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PubMed2002

Cortical representation of auditory space: information-bearing features of spike patterns.

Previous studies have demonstrated that the spike patterns of cortical neurons vary systematically as a function of sound-source location such that the response of a single neuron can signal the location of a sound source throughout 360 degrees of azimuth. The present study examined specific features of spike patterns that might transmit information related to sound-source location. Analysis was based on responses of well-isolated single units recorded from cortical area A2 in alpha-chloralose-anesthetized cats. Stimuli were 80-ms noise bursts presented from loudspeakers in the horizontal plane; source azimuths ranged through 360 degrees in 20 degrees steps. Spike patterns were averaged across samples of eight trials. A competitive artificial neural network (ANN) identified sound-source locations by recognizing spike patterns; the ANN was trained using the learning vector quantization learning rule. The information about stimulus location that was transmitted by spike patterns was computed from joint stimulus-response probability matrices. Spike patterns were manipulated in various ways to isolate particular features. Full-spike patterns, which contained all spike-count information and spike timing with 100-micros precision, transmitted the most stimulus-related information. Transmitted information was sensitive to disruption of spike timing on a scale of more than approximately 4 ms and was reduced by an average of approximately 35% when spike-timing information was obliterated entirely. In a condition in which all but the first spike in each pattern were eliminated, transmitted information decreased by an average of only approximately 11%. In many cases, that condition showed essentially no loss of transmitted information. Three unidimensional features were extracted from spike patterns. Of those features, spike latency transmitted approximately 60% more information than that transmitted either by spike count or by a measure of latency dispersion. Information transmission by spike patterns recorded on single trials was substantially reduced compared with the information transmitted by averages of eight trials. In a comparison of averaged and nonaveraged responses, however, the information transmitted by latencies was reduced by only approximately 29%, whereas information transmitted by spike counts was reduced by 79%. Spike counts clearly are sensitive to sound-source location and could transmit information about sound-source locations. Nevertheless, the present results demonstrate that the timing of the first poststimulus spike carries a substantial amount, probably the majority, of the location-related information present in spike patterns. The results indicate that any complete model of the cortical representation of auditory space must incorporate the temporal characteristics of neuronal response patterns.

Action Potentials↗
PubMed1985

Pattern evoked potentials from the cat's retina.

We have studied electroretinograms (ERG) in the cat using phase-reversed sinusoidal gratings as a stimulus. Our purpose was to characterize response properties of this type of ERG. One basic question we addressed was whether the response to a grating stimulus is actually pattern specific. For the purpose of comparison, we used the same stimulus to investigate mass potentials from the lateral geniculate nucleus (LGN) and the visual cortex. The pattern ERG consists mainly of a vitreous negative after potential peaking shortly (120-200 ms) after reversal of the pattern. There is a notable absence in the pattern ERG of a b-wave that, however, can be elicited by a step increase of luminance over a uniform field. Pattern ERG amplitudes decrease monotonicaly with increasing spatial frequency and show no low-frequency attenuation when the pattern is phase reversed in square-wave fashion. This is markedly different than evoked potentials from the LGN and visual cortex that show band-pass characteristics. On the other hand, sinusoidal phase reversal reveals a clear attenuation of the pattern ERG amplitude at low spatial frequencies, whereas this type of stimulation produces very poor responses from LGN and visual cortex. The low spatial-frequency attenuation in the pattern ERG shows that the generating mechanism involves lateral interactions. There is thus a clear pattern-specific component in the pattern ERG. The pattern ERG has a surprisingly high contrast threshold relative to those estimated from cortical and LGN evoked potentials. Above threshold, pattern ERG response amplitude increases rapidly with contrast, but it often shows saturation at high contrast levels. These saturation points are generally high when contrast thresholds are high so that the rising portion of the contrast-response functions have fairly uniform slopes. Contrast-response curves from the LGN and cortical potentials are quite different from those for the retina in that amplitudes increase approximately linearly with log contrast over a 2-log-unit range (1 to 100%).

Animals↗
PubMed1986

PAD and PAH response patterns of group Ia- and Ib-fibers to cutaneous and descending inputs in the cat spinal cord.

The characteristics of the primary afferent depolarization (PAD) of Ia- and Ib-fibers generated by segmental and descending inputs have been analyzed in the spinal cord of anesthetized cats. The PAD was inferred from the changes produced by conditioning inputs on the intraspinal stimulus current required to produce a constant antidromic firing of single group I afferent fibers from the gastrocnemius (GS) or posterior biceps and semitendinosus (PBSt) nerves. Group I GS and PBSt fibers ending in the intermediate nucleus could be classified in three different types according to their PAD patterns in response to stimulation of cutaneous nerves and of descending fibers. In one set of group I fibers stimulation of cutaneous nerves and of the ipsilateral brain stem reticular formation, or the contralateral red nucleus, produced no PAD, but was able to inhibit the PAD generated by stimulation of group I fibers from flexors (type A PAD pattern). PBSt nerve fibers with this PAD pattern had peripheral thresholds and conduction velocities between 1.01 and 1.56 times threshold and 76.3 to 118 m/s, respectively. A second set of group I fibers was found to be depolarized by cutaneous nerves as well as by stimulation of rubrospinal and reticulospinal fibers (type B PAD pattern). The peripheral thresholds and conduction velocities of PBSt afferent fibers with a type B PAD pattern were of 1.66-2.03 times threshold and 71-83 m/s, respectively. We found a third set of group I fibers that were also depolarized by reticulospinal and rubrospinal inputs, but not by cutaneous nerves that instead inhibited the PAD elicited by group I volleys in flexor nerves (type C PAD pattern). All PBSt afferent fibers with a type C PAD pattern, with the exception of two, had peripheral thresholds and velocities between 1.46 and 2.16 times threshold and between 72 and 89 m/s, respectively. Stimulation of the Deiter's nucleus was found to depolarize the intraspinal terminals of a small fraction of group I GS fibers with a type A PAD pattern and of all group I GS and PBSt fibers with type B and C PAD patterns. The PAD produced by vestibulospinal stimulation in fibers with type A and C PAD patterns could be inhibited by conditioning volleys applied to cutaneous nerves. It is suggested that group I afferent fibers from flexors and extensors with a type A PAD pattern are group Ia, and that most fibers with type B and type C PAD patterns are group Ib.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1994

Intrinsic discharge patterns and somatosensory inputs for neurons in raccoon primary somatosensory cortex.

1. Discharge patterns of neurons are regulated by synaptic inputs and by intrinsic membrane properties such as their complement of ionic conductances. Discharge patterns evoked by synaptic inputs are often used to identify the source and modality of sensory input. However, the interpretation of these discharge patterns may be complicated if different neurons respond to the same synaptic input with a variety of discharge patterns due to differences in intrinsic membrane properties. The purposes of this study were 1) to investigate intrinsic discharge patterns of neurons in primary somatosensory cortex of raccoon in vivo and 2) to use somatosensory postsynaptic potentials evoked by stimulation of forepaw digits to determine thalamocortical connectivity for the same neurons. 2. Conventional intracellular recordings with sharp electrodes were made from 121 neurons in the cortical representation of glabrous skin of digit four (d4). Intracellular injection of identical current pulses (100-120 ms in duration) elicited various patterns of discharge in different neurons. Neurons were classified on the basis of these intrinsic patterns of discharge, rates of spike adaptation, and characteristics of spike waveforms. Three main groups were identified: regular spiking (RS) neurons, intrinsic bursting (IB) neurons, and fast spiking (FS) neurons. Subclasses were identified for the RS and IB groups. 3. Neurons were tested for somatosensory inputs by stimulating electrically d3, d4, and d5. Excitatory postsynaptic potentials (EPSPs) were elicited in 100% of the neurons by electrical stimulation of d4, the "on-focus" digit. EPSPs were usually followed by inhibitory postsynaptic potentials (IPSPs). Many neurons (41%) responded with EPSP-IPSP sequences after stimulation of d3 or d5, the "off-focus" digits. 4. Latencies of somatosensory EPSPs and IPSPs were used to determine the synaptic order in the cortical circuitry of RS, IB, and FS neurons. EPSPs with monosynaptic thalamocortical latencies were recorded in RS, IB, and FS neurons. 5. We conclude that precise patterns of neural discharge in primary somatosensory cortex cannot be reliable estimates of sensory inputs reaching these neurons because patterns of discharge are so strongly influenced by intrinsic membrane properties. Ionic conductances governing patterns of neuronal discharge seem almost identical in intact cortex of raccoon, rat, and cat, and in slices of rodent cortex, because similar patterns of discharge are found. The consistency of patterns of discharge across species and types of preparation suggests that these intrinsic membrane properties are a general property of cerebral cortical neurons and should be considered when evaluation sensory coding by these neurons.

Animals↗
PubMed2000

Predictive modulation of muscle coordination pattern magnitude scales fingertip force magnitude over the voluntary range.

Human fingers have sufficiently more muscles than joints such that every fingertip force of submaximal magnitude can be produced by an infinite number of muscle coordination patterns. Nevertheless, the nervous system seems to effortlessly select muscle coordination patterns when sequentially producing fingertip forces of low, moderate, and maximal magnitude. The hypothesis of this study is that the selection of coordination patterns to produce submaximal forces is simplified by the appropriate modulation of the magnitude of a muscle coordination pattern capable of producing the largest expected fingertip force. In each of three directions, eight subjects were asked to sequentially produce fingertip forces of low, moderate, and maximal magnitude with their dominant forefinger. Muscle activity was described by fine-wire electromyograms (EMGs) simultaneously collected from all muscles of the forefinger. A muscle coordination pattern was defined as the vector list of the EMG activity of each muscle. For all force directions, statistically significant muscle coordination patterns similar to those previously reported for 100% of maximal fingertip forces were found for 50% of maximal voluntary force. Furthermore the coordination pattern and fingertip force vector magnitudes were highly correlated (r > 0.88). Average coordination pattern vectors at 50 and 100% of maximal force were highly correlated with each other, as well as with individual coordination pattern vectors in the ramp transitions preceding them. In contrast to this consistency of EMG coordination patterns, predictions using a musculoskeletal computer model of the forefinger show that force magnitudes </=50% of maximal fingertip force can be produced by coordination patterns drastically different from those needed for maximal force. Thus when modulating fingertip force magnitude across the voluntary range, the number of contributing muscles and the relative activity among them was not changed. Rather, the production of low and moderate forces seems to be simplified by appropriately scaling the magnitude of a coordination pattern capable of producing the highest force expected.

Adult↗
PubMed2006

Dietary patterns and risk of prostate cancer in U.S. men.

We prospectively investigated the associations between dietary patterns and risk of prostate cancer in the Health Professionals Follow-up Study. Between 1986 and 2000, 3,002 incident prostate cancer cases were identified in our cohort. Using factor analysis, two major dietary patterns were identified, a prudent and a western dietary pattern. Dietary patterns were not appreciably associated with risk of total prostate cancer. For the highest versus the lowest quintiles, the multivariable relative risk (RR) for the prudent pattern was 0.94 [95% confidence interval (CI), 0.83-1.06], and for the western pattern, the multivariable RR was 1.03 (95% CI, 0.92-1.17). Neither were these associated with risk of advanced prostate cancer [highest versus lowest quintile, prudent pattern (RR, 1.01; 95% CI, 0.68-1.49); western pattern (RR, 1.13; 95% CI, 0.77-1.67)]. Higher western pattern scores were suggestively associated with a greater risk of advanced prostate cancer among older men [highest versus lowest quintile (RR, 1.35; 95% CI, 0.97-1.90)], but not after adding processed meat to the model [highest versus lowest quintile (RR, 1.11; 95% CI, 0.75-1.65)]. We did not find any evidence for a protective association between prudent pattern and risk of prostate cancer. The lack of association between a western dietary pattern as identified by factor analysis in our cohort and prostate cancer risk suggests that dietary risk factors for prostate cancer are likely to differ from those for other conditions, such as cardiovascular disease and type 2 diabetes, that have been associated with a western dietary pattern in this cohort.

Adult↗
PubMedDate not supplied

Carcinoembryonic antigen staining patterns at the invasive tumor margin predict the malignant potential of colorectal carcinoma.

Immunohistochemical carcinoembryonic antigen (CEA) staining patterns at the invasive tumor margin were correlated with malignant potential in 64 advanced colorectal carcinomas. Twenty-two (34%) carcinomas showed an apical and 42 (66%) a cytoplasmic staining pattern. Carcinomas with a cytoplasmic pattern had a higher incidence of lymph node (71 versus 41%; p < 0.05) and liver (50 versus 23%; p < 0.05) metastasis and higher levels of serum CEA (p < 0.01) than those with an apical staining pattern. Nine of 11 recurrent tumors had a cytoplasmic pattern and 2 had an apical pattern (p < 0.05). Among carcinomas having the same degree of differentiation, those with a cytoplasmic CEA staining pattern were more aggressive. Six (55%) well-differentiated carcinomas with a cytoplasmic pattern metastasized to the liver while none with an apical pattern did (p < 0.05). Moderately differentiated carcinomas with a cytoplasmic pattern had a significantly higher incidence of lymph node metastasis than those with an apical pattern (77 versus 46%; p < 0.05). When colorectal carcinomas are examined at the invasive tumor margin, an evaluation of the CEA staining pattern is useful in recognizing carcinomas having a higher potential to metastasize and recur after curative surgery.

Adenocarcinoma↗
PubMed1998

Tidal expired airflow patterns in adults with airway obstruction.

Earlier studies have shown that time and flow indices derived from tidal expiratory flow patterns can be used to distinguish the severity of airway obstruction. This study was designed to address two aspects of tidal expiratory flow patterns: 1) how do expiratory flow patterns differ between subjects with normal and obstructed airways; and 2) can a sensitive index of airway obstruction be derived from these pattern differences? Tidal expiratory flow patterns from 66 adult subjects with varying degrees of airway obstructive disease with a forced expiratory volume in one second (FEV1) of 20-121% predicted were examined. In each subject, the expired flow pattern from each consecutive breath was scaled and then averaged together to create a single expired pattern. A detailed examination of the scaled flow patterns in 12 subjects (six with normal airways and six with airway obstruction) showed that the shape of the post-peak expiratory flow portion was different in the subjects with airway obstruction. A slope index, S, was derived from the scaled patterns and found to be sensitive to the severity of airway obstruction, correlating with FEV1 (% pred) with r2=0.74 (p<0.05, n=57). The S index also correlated (r2=0.36, p<0.05, n=47) with the functional residual capacity (FRC) (% pred) which was >100% in subjects with severe airway obstruction and lung overinflation. In subjects with normal airways, three further airflow patterns could be distinguished, which were different from the patterns seen in subjects with the severest airway obstruction. Scaled flow patterns from tidal expiration collected from uncoached subjects, can be used to derive an index of airway obstruction.

Adolescent↗
PubMed2005

Histopathologic pattern and clinical features of rheumatoid arthritis-associated interstitial lung disease.

STUDY OBJECTIVES: To investigate the histopathologic pattern and clinical features of patients with rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) according to the American Thoracic Society (ATS)/European Respiratory Society consensus classification of idiopathic interstitial pneumonia. DESIGN: Retrospective review. SETTING: Two thousand-bed, university-affiliated, tertiary referral center. PATIENTS: Eighteen patients with RA who underwent surgical lung biopsy (SLBx) for suspected ILD. METHOD: SLBx specimens were reviewed and reclassified by three lung pathologists according to the ATS/European Respiratory Society classification. Clinical features and follow-up courses for the usual interstitial pneumonia (UIP) pattern and the nonspecific interstitial pneumonia (NSIP) pattern were compared. RESULTS: The histopathologic patterns were diverse: 10 patients with the UIP pattern, 6 patients with the NSIP pattern, and 2 patients with inflammatory airway disease with the organizing pneumonia pattern. RA preceded ILD in the majority of patients (n = 12). In three patients, ILD preceded RA; in three patients, both conditions were diagnosed simultaneously. The majority (n = 13) of patients had a restrictive defect with or without low diffusion capacity of the lung for carbon monoxide (D(LCO)) on pulmonary function testing; 2 patients had only low (D(LCO)). The UIP and NSIP groups were significantly different in their male/female ratios (8/2 vs 0/6, respectively; p = 0.007) and smoking history (current/former or nonsmokers, 8/2 vs 0/6; p = 0.007). Many of the patients with the UIP pattern had typical high-resolution CT features of UIP. Five patients with the UIP pattern died, whereas no deaths occurred among patients with the NSIP pattern during median follow-up durations of 4.2 years and 3.7 years, respectively. CONCLUSIONS: The histopathologic type of RA-ILD was diverse; in our study population, the UIP pattern seemed to be more prevalent than the NSIP pattern.

Adult↗
PubMed2004

Association between patterns of maternal substance use and infant birth weight, length, and head circumference.

OBJECTIVE: To determine the effects of patterns of drug use during term pregnancy on infant growth parameters at birth. METHODS: Histories of cocaine, opiate, alcohol, tobacco, and marijuana use during the 3-month period before pregnancy and the 3 trimesters of pregnancy were recorded at the infants' 1-month visit. Patterns of use were categorized as consistently high, moderate, or low/none or increasing/decreasing, and effects on growth parameters were analyzed in multivariate linear regression analyses, with adjustment for clinical site, maternal age, prepregnancy weight, multidrug use, and socioeconomic status. RESULTS: A total of 241 cocaine-exposed women and 410 non-cocaine-exposed women participated in the study. In the cocaine-exposed group, 75% used alcohol, 90% used tobacco, and 53% used marijuana; in the non-cocaine-exposed group, 57% used alcohol, 34% used tobacco, and 19% used marijuana. Birth weight, birth length, and head circumference were significantly greater among infants born to women who used no drugs, compared with women with any cocaine, opiate, alcohol, tobacco, or marijuana use, and were greater among infants born to cocaine nonusers, compared with cocaine users. With adjustment for confounders, birth weight was significantly affected by cocaine (deficit of 250 g with consistently low pattern) and tobacco (deficits of 232 g with consistently high pattern, 173 g with consistently moderate pattern, 153 g with decreasing pattern, and 103 g with consistently low pattern). Head size was affected by cocaine (deficit of 0.98 cm with consistently moderate pattern) and tobacco (deficits of 0.72 cm with consistently high pattern and 0.89 cm with consistently moderate pattern). Birth length was affected by tobacco use only (deficits of 0.82 cm with consistently high pattern and 0.98 cm with decreasing use). CONCLUSION: Patterns of tobacco use during pregnancy affect birth weight, length, and head circumference, whereas cocaine affects birth weight and head size, when adjustments are made for confounders, including multidrug use.

Birth Weight↗
PubMed1997

Relationship between scrotal infrared temperature patterns and natural-mating fertility in beef bulls.

The infrared temperature pattern (IRT) of the scrotal surface was recorded for 73 yearling beef bulls and a color video thermogram of the pattern of each bull was recorded. The average scortal surface temperature, temperature at the top and bottom of the scrotum, scortal temperature gradient, and thermal class (normal, questionable, or abnormal scortal surface thermal pattern) were recorded for each thermogram. Thirty-seven bulls had a normal temperature pattern (51%), 20 had a questionable pattern (27%), and 16 had an abnormal temperature pattern (22%). Bulls exhibiting abnormal scrotal temperature patterns had lower (P < .05) percentages of sperm exhibiting normal head and tail morphology and had a higher (P < .01) percentage of sperm with proximal droplets than did bulls with normal or questionable thermogram patterns. Thirty bulls with acceptable testis size and semen quality and representing the three thermal classes were each exposed single-sire to approximately 18 heifers during a 45-d pasture breeding period. Pregnancy rate was lower (P < .01) for bulls with abnormal scrotal temperature patterns (68 +/- 4%, n = 8) than for bulls with normal (83 +/- 4%, n = 13) and questionable temperature patterns (85 +/- 4%, n = 9), and pregnancy rate was related significantly to all four major characteristics (surface, top, and bottom temperatures and temperature gradient) of scortal thermograms. Data indicated that bulls with abnormal scortal temperature patterns exhibited a reduced ability to maintain an effective thermal gradient from top to bottom of the testes and that bulls with abnormal scrotal temperature patterns achieved reduced pregnancy rates when used for natural mating.

Animals↗
PubMedDate not supplied

Patterns of changes of tumour temperatures during clinical hyperthermia: implications for treatment planning, evaluation and control.

The patterns of changes in tumour temperatures were studied at selected times throughout 104 hyperthermia sessions. Temperature change patterns were analysed in the context of the known patterns of change of the applied power. First, of 69 extracranial treatments analysed, 74% indicated relatively flat temperatures at constant applied power during a major portion of the treatment, thereby indicating that during that time there were no major changes in any of the physical or physiological tissue parameters which contribute to the ability of the tumour tissue to remove energy (Pattern 1). Second, after reaching an initial steady state, approximately 14% of these extracranial treatments showed either steadily decreasing temperatures at constant power, or constant temperatures at steadily increasing applied power, thereby indicating that the tumour's ability to remove energy was steadily increasing in time following the initial steady state (Pattern 2). Finally, after reaching an initial steady state, the remaining 12% of these treatments showed a pronounced decrease in temperature occurring about 10-20 min into the treatment followed by increasing temperatures or levelling off of temperatures at a higher value than the temperature minimum that had occurred, all at constant applied power (Pattern 3). Of 35 brain treatments analysed, 80% followed Pattern 1, 14% followed Pattern 2, and 6% followed Pattern 3. Intratumoral heterogeneity was evident in some cases with approximately 44% of all treatments having at least one individual temperature sensor change in a manner that did not follow the average direction of change when all sensors were combined. For seven patients with permanent probes, the patterns of change presented in the first treatments were also observed during six out of seven of the second treatments. In addition, three out of the five patients who had an evaluable third treatment showed a pattern of change during that third treatment that was similar to the pattern observed in both treatment one and treatment two.

Body Temperature↗
PubMed1998

Vibrotactile pattern isolation/integration.

Temporal integration has been cited as a major factor in temporal masking. Two experiments were designed to examine the conditions under which temporal integration may aid or hinder the perception of vibrotactile spatial patterns. In Experiment 1, the subject's task was to discriminate between pairs of patterns. Each pattern was composed of two temporally separated pattern elements. When the task required the subjects to perceive the individual pattern elements, performance improved with temporal isolation--that is, performance improved as the temporal separation between the elements increased. In a second task, when the discrimination could be based on either the overall pattern shape or the pattern elements, temporal integration appeared to improve performance--that is, performance improved as the temporal separation decreased. In Experiment 2, an identification task was used. Several factors appeared to determine whether temporal integration aided or hindered pattern identification. When pattern elements similar to those in Experiment 1 were tested, performance improved with increasing temporal separation (isolation). A single function was fit to the discrimination (isolation) and identification (isolation) results. Whether temporal integration aids or hinders pattern perception appears to depend on pattern shape, the pattern elements, and the nature of the task.

Female↗
PubMed1993

Perceptual organization of auditory temporal patterns in European starlings (Sturnus vulgaris).

The perception of continuously repeating auditory patterns by European starlings was explored in seven experiments. In Experiment 1, 4 starlings learned to discriminate between two continuously repeating, eight-element, auditory patterns. Each eight-element pattern was constructed from different temporal organizations of two elements differing in timbre. In Experiments 2-7, the repeating patterns were transformed in ways designed to identify the starlings' perceptual organization of the patterns. In Experiment 2, the starlings identified patterns beginning with novel starting points. In Experiment 3, discrimination performance was adversely affected by reorganizing the elements in the patterns. In Experiments 4 and 5, the pattern elements were altered. In Experiment 4, the patterns were constructed from two novel elements. In Experiment 5, the temporal location of the two pattern elements was reversed. The transformations of the patterns in Experiments 4 and 5 affected discrimination performance for some, but not all, of the starlings. In Experiments 6 and 7, replacing either of the two elements with silent intervals had no effect on discrimination performance. The results of these experiments identify basic grouping principles that starlings use when they perceive auditory patterns.

Animals↗
PubMed1997

Tactile pattern perception by two fingers: temporal interference and response competition.

The identification of a spatial pattern (target) presented to one fingerpad may be interfered with by the presentation of a second pattern (nontarget) to either the same fingerpad or a second fingerpad. A portion of the interference appears to be due to masking and a portion to response competition. In the present study, vibrotactile spatial patterns were designed to extend over two fingerpads. Target and nontarget patterns were presented to the same two fingerpads with a temporal separation between the two patterns. The function relating target identification to the temporal separation between the target and nontarget was very similar to the functions obtained with one-finger patterns in temporal masking studies. Subsequent measurements showed that a substantial portion of the interference resulted from response competition. Pattern categorization was better when patterns were presented to two fingers on opposite hands than to two fingers on the same hand; however, there was more interference for patterns presented bilaterally than for patterns presented ipsilaterally. The results supported the conclusion that similar processes are involved in the perception of sequences of spatial patterns whether the patterns are presented to one or to two fingers.

Adult↗
PubMed2002

Acute fibrinous and organizing pneumonia: a histological pattern of lung injury and possible variant of diffuse alveolar damage.

CONTEXT: The histologic patterns of diffuse alveolar damage (DAD), bronchiolitis obliterans with organizing pneumonia (BOOP), and eosinophilic pneumonia (EP) are well-recognized histologic patterns of lung injury associated with an acute or subacute clinical presentation. We have recognized acute fibrinous and organizing pneumonia (AFOP) as a histologic pattern, which also occurs in this clinical setting but does not meet the classic histologic criteria for DAD, BOOP, or EP and may represent an underreported variant. OBJECTIVE: To investigate the clinical significance of the AFOP histologic pattern and to explore its possible relationship to other disorders, including DAD and BOOP. DESIGN: Open lung biopsy specimens and autopsy specimens were selected from the consultation files of the Armed Forces Institute of Pathology, which showed a dominant histologic pattern of intra-alveolar fibrin and organizing pneumonia. Varying amounts of organizing pneumonia, type 2 pneumocyte hyperplasia, edema, acute and chronic inflammation, and interstitial widening were seen. Cases with histologic patterns of classic DAD, BOOP, abscess formation, or eosinophilic pneumonia were excluded. To determine the clinical behavior of patients with this histologic finding, clinical and radiographic information and follow-up information were obtained. Statistical analysis was performed using Kaplan-Meier and chi(2) analysis. RESULTS: Seventeen patients (10 men, 7 women) with a mean age of 62 years (range, 33-78 years) had acute-onset symptoms of dyspnea (11), fever (6), cough (3), and hemoptysis (2). Associations believed to be clinically related to the lung disease included definitive or probable collagen vascular disease (3), amiodarone (1), sputum culture positive for Haemophilus influenza (1), lung culture positive for Acinetobacter sp. (1), lymphoma (1), hairspray (1), construction work (1), coal mining (1), and zoological work (1). Six patients had no identifiable origin or association. Follow-up revealed 2 clinical patterns of disease progression: a fulminate illness with rapid progression to death (n = 9; mean survival, 0.1 year) and a more subacute illness, with recovery (n = 8). Histologic analysis and initial symptoms did not correlate with eventual outcome, but 5 of the 5 patients who required mechanical ventilation died (P =.007). CONCLUSIONS: Acute fibrinous and organizing pneumonia is a histologic pattern associated with a clinical picture of acute lung injury that differs from the classic histologic patterns of DAD, BOOP, or EP. Similar to these patterns of acute lung injury, the AFOP pattern can occur in an idiopathic setting or with a spectrum of clinical associations. The overall mortality rate is similar to DAD and therefore may represent a histologic variant; however, AFOP appears to have 2 distinct patterns of disease progression and outcome. The need for mechanical ventilation was the only parameter that correlated with prognosis. None of the patients with a subacute clinical course required mechanical ventilation.

Acute Disease↗
PubMed2006

[X chromosome inactivation patterns in patients with Rett syndrome and their mothers and the parental origin of the priority inactive X chromosome].

OBJECTIVE: Rett syndrome (RTT) is a severe childhood neurodevelopmental disorder mainly affecting females. The pathogenic gene is located at Xq28, which codes for the methyl-CpG-binding protein 2. MECP2 gene is affected by X chromosome inactivation (XCI). The different XCI patterns of females could affect the expression ratios of pathogenic gene, causing changes in clinical symptoms. In order to understand the XCI patterns in RTT patients and the relationship between XCI pattern, genotype and phenotype, the XCI patterns in patients with RTT and their mothers, the parental origin of the priority inactive X chromosome in RTT, and the relations of XCI patterns with genotype and phenotype in RTT cases were analyzed. METHODS: Genomic DNA was extracted from peripheral blood of 55 cases with RTT (52 with MECP2 mutations, 3 without mutations), 53 mothers of RTT cases and 48 normal female controls. DNA was digested with methylation sensitive restriction endonuclease Hpa II. Then the undigested and digested DNAs were amplified via PCR for the first exon of human androgen receptor (AR) gene. PCR products were analyzed by Genescan. RESULTS: The heterozygotic rates of AR gene were 82%, 77% and 83% in RTT patients, mothers and controls, respectively. XCI distribution pattern of RTT was different from that of the mothers and control, P < 0.05. More mothers and controls than RTT patients were in the area of XCI 50:50 - 59:41. The differences between them were statistically significant (P < 0.05). No significant difference in XCI distribution patterns between mothers and the control groups was found (P > 0.05). Non-random XCI rates in the areas of XCI >or= 65:35 and >or= 80:20 were 53.35% and 17.8%, respectively, in RTT patients, compared with the mothers group (36.6%, 7.3%) and control group (35%, 10%), it was higher in RTT patients, but the difference was not statistically significant (P > 0.05). In 18 of 21 cases with XCI >or= 65:35, the priority inactive X chromosome was of paternal origin (85.7%). Variable XCI patterns were observed in the same gene mutation patients. The highly skewed XCI as well as the random XCI were found in patients with mild, severe and typical phenotype. The rate of highly skewed XCI in atypical patients was higher than that in typical RTT patients. The rate of highly skewed XCI in T158M was higher than the other type mutations. No highly skewed XCI was observed in cases with R133C mutation. CONCLUSION: The XCI distribution pattern of RTT patients was different from that of RTT mother and control groups. There was no significant difference in XCI distribution patterns between mothers and the control groups. It was not a main genetic pattern in RTT that mothers as the carriers to transmit the pathogenic gene to the patients. Non-random XCI was not the main XCI pattern in RTT patients. The priority inactive X chromosome was mainly of paternal origin. XCI could modify the clinical phenotype of RTT, but had limitations in explaining all the phenotypes manifested in RTT cases.

Adolescent↗
PubMed1991

Patterns of DNA methylation in selected human genes in different Hodgkin's lymphoma and leukemia cell lines and in normal human lymphocytes.

The human genome, like many other genomes, harbors highly specific patterns of DNA methylation which have not yet been systematically studied. In a limited investigation on the genes for tumor necrosis factors-alpha and -beta, a surprising interindividual concordance in the patterns of DNA methylation at the nucleotide level has been demonstrated earlier by using the genomic sequencing method on DNA from individuals of very different ethnic origins. Patterns of DNA methylation could perhaps serve as indicators for genetic activities. These activities would not have to be restricted to gene transcription but could relate to other genetic activities in the cell. DNA methylation patterns are known to be cell type-specific. We have now initiated a study of these DNA patterns in human lymphocytes and in human cell lines of different malignant origins. Several of the proto-oncogenes, parts of the genes for tumor necrosis factor-alpha and -beta, the insulin receptor and lamin C have been used as hybridization probes. We have relied to some extent on the documented observation that the methylation patterns at 5'-CCGG-3' (HpaII/MspI) sequences yield a reflection of patterns at all 5'-CG-3' sequences. Three main types of patterns have been observed. Some of the probed segments are completely unmethylated; others are fully methylated, most of the areas are partly methylated exhibiting complex patterns at the 5'-CCGG-3' sites. In different tumor cell lines, different DNA methylation patterns are apparent for the same DNA probes. Comparisons of the methylation patterns in a given DNA segment between DNA from primary normal human lymphocytes and DNA from different tumor cell lines reveal changes in these patterns in several instances.

Base Sequence↗