Cause of perimesencephalic hyperattenuation in cases of ruptured vertebrobasilar aneurysm.
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Aneurysm, Ruptured↗
Biomedical subjects
D Friedman
Publications and source records attributed to D Friedman.
Negative and positive dimensions of schizotypal personality disorder.
The positive (perceptual-cognitive) and negative (social-interpersonal) dimensions of schizotypal personality traits were examined in biological relatives of individuals with Axis I disorder. The subjects were young adult offspring from three contrasting parental groups, including schizophrenic disorder, affective disorder, and normal controls. Cognitive correlates, including digit span (presumed to assess working memory) and P3 amplitudes, were also examined. Preliminary results showed that positive and negative dimensions were distinguished by different prevalence patterns in the offspring subjects, and by a different pattern of correlations with cognitive measures. Negative dimensions were more frequent in offspring from the schizophrenic parental group than in the offspring from affective disorder and normal control parental groups. Digits forward and backward, and P3 amplitude decrements, characterized a subset of offspring with negative features from the schizophrenic parental group. Positive dimensions did not differ between the psychiatric parental groups, and did not covary with digit span or P3 amplitude assessments. These results support the view that positive and negative dimensions may reflect separable pathophysiologic processes.
Adult↗
Effect of multiple presentations of words on event-related potential and reaction time repetition effects in Alzheimer's patients and young and older controls.
The hallmark symptom in probable Alzheimer's disease (PAD) is dramatic difficulty in storing and/or retrieving new information on tests of explicit or direct memory. However, in many studies of implicit or indirect memory, these same patients show repetition-priming magnitudes (i.e., facilitation of performance on the basis of previous experience) similar to that of normal controls. Recent studies of repetition priming have shown that PAD subjects have an intact event-related potential (ERP) repetition effect, which is thought to index indirect memory functioning. The present study was designed to test the effect of multiple repetitions of verbal stimuli on the ERPs of PAD patients. ERPs were recorded from 8 subjects with PAD, 8 age-matched elderly and 16 young healthy controls. Subjects were asked to make speeded but accurate choice responses to infrequently occurring animal words and frequently occurring nonanimal words, some of which repeated across three blocks of trials. All groups of subjects produced ERP activity that was more positive to repeated (i.e., old) than to new items, with no additional enhancement elicited by the third presentation. ERP enhancement to repeated items was associated with reaction time facilitation, which also showed no additional facilitation to the third presentation. Moreover, the scalp distribution of the repetition effect was similar in the PAD and control groups, suggesting that it emanated from similar brain tissue in the three groups. These results indicate that ERP and reaction time repetition-priming effects are relatively intact in subjects who are aging normally and in those with a diagnosis of "mild" Alzheimer's disease.
Adult↗
ERPs during study as a function of subsequent direct and indirect memory testing in young and old adults.
Event-related potentials (ERPs) were recorded from young and older adults while words were studied during structural and semantic encoding tasks. Items were presented twice to assess repetition effects. Subsequent memory effects (i.e. Dm or difference in subsequent memory) associated with non-target study items were also evaluated. Memory for non-target study items was tested either indirectly (word stem completion) or directly (cued recall). There were small, but unreliable age differences (favoring the young) on both the indirect and direct tests. These small differences were consistent with previous results for stem completion performance, but were counter to expectation for the cued recall test, where young adults were expected to show clear superiority. We conclude, based on task considerations, that for cued recall, subjects may have adopted an 'implicit' retrieval strategy. Because older adults typically have little difficulty with implicit retrieval, they fared almost as well as the young on cued recall. Dm effects were reliable for the young only. As Dm is thought to reflect elaborative encoding processes, the larger Dm magnitudes in the young than the old suggest that the small, though unreliable, age-related performance differences that resulted may have been mediated by such elaborative processing on the part of the younger adults.
Adult↗
Biliopancreatic diversion for obesity at eighteen years.
BACKGROUND: Surgical attempts to treat obesity began because of the discouraging results of conservative medical treatment, which successfully achieved initial weight loss but failed to maintain it. Gastric restrictive procedures, currently the most popular surgical methods for obesity therapy, have proved to be effective in initiating weight loss, but some concerns regarding their long-term efficacy in weight maintenance have arisen. METHODS: Of a total of 1968 obese patients who underwent biliopancreatic diversion since 1976, the last consecutive 1217 underwent the "ad hoc stomach" type of diversion with a 200 cm alimentary limb, a 50 cm common limb, and a gastric volume varying between 200 and 500 ml. Mean age was 37 years old (11 to 69 years), and mean excess weight was 117%. Maximum follow-up was 115 months with nearly 100% participation. RESULTS: In the last half of the series, operative mortality was 0.4% with no general complications and with early surgical complications of wound dehiscence and infection (total, 1.2%) and late complications of incisional hernia (8.7%) and intestinal obstruction (1.2%). Mean percent loss initial excess weight (IEW) at 2, 4, 6, and 8 years was 78 +/- 16, 75 +/- 16, 78 +/- 18, and 77 +/- 16 in the patients with IEW up to 120% and 74 +/- 12, 73 +/- 13, 73 +/- 12, and 72 +/- 10 in those with IEW more than 120%. A group of 40 patients who underwent the original "half-half" biliopancreatic diversion maintained a mean 70% reduction of IEW during a 15-year follow-up period. Specific late complications included anemia (less than 5%), stomal ulcer (2.8%), protein malnutrition (7% with 1.7% requiring surgical revision by common limb elongation or by restoration). Clinical problems from bone demineralization were minimal in the short term and almost absent in the long term. CONCLUSIONS: Biliopancreatic diversion is a very effective procedure but is potentially dangerous if used incorrectly.
Adolescent↗
Improved oral delivery of desmopressin via a novel vehicle: mucoadhesive submicron emulsion.
PURPOSE: Desmopressin acetate (DDAVP) is used parenterally and intranasally in the control of several diseases. Oral administration of DDAVP, while most desirable, is not practical presently due to low bioavailability. The objective of the present study was to explore the feasibility for employing oil-in-water MucoAdhesive SubMicron Emulsion (MA-SME), a novel mucoadhesive vehicle with polymer-coated droplets, for enhanced oral delivery of DDAVP. METHODS: We used a modified pharmacopeal method, based on measurement of the antidiuretic activity, for the assessment of oral delivery of DDAVP in rats. DDAVP formulated in two MA-SME preparations, in non-mucoadhesive SME (plain-SME), in saline and in other control solutions was administered orally to rats via a stomach tube at a dose of 0.5 units/kg. At various times following DDAVP administration, water was given via a stomach tube. Excretion times for 30% and 60% of the total water load were measured. RESULTS: Excretion times for DDAVP in MA-SME formulations were always longer (up to 2-fold) than those following DDAVP in saline. By contrast, excretion times for DDAVP in plain-SME and in non-SME Carbopol (a Mucoadhesive polymer) solution were virtually identical to those for DDAVP in saline. CONCLUSIONS: Formulations of MA-SME were shown to generate substantial enhancement (up to 12-fold) of the rat oral bioavailability of DDAVP with regard to simple saline solution of the drug. From the results it is also evident that MA-SME, but not plain-SME or non-SME Carbopol solution, is responsible for the enhancement of oral delivery of DDAVP in rats.
Administration, Oral↗
Nomenclature of the genes encoding IHF.
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Bacterial Proteins↗
The air gun: toy or weapon?
Originally used in warfare, air guns are commonly used in target shooting, as toys, and as "beginner" guns for children. The projectile force of these weapons can rival that of many conventional handguns. Pneumatic weapons pose a serious threat to the pediatric population, and their potential for serious injury must be recognized.
Brain Injuries↗
Naming norms for brief environmental sounds: effects of age and dementia.
Brief nontonal sounds are used in electrophysiology in the novelty oddball paradigm. These sounds vary in the brain activity they elicit and in the degree to which they can be identified, named, and remembered. Because ease of sound identification may influence sound processing, naming and conceptual norms were determined for 100 sounds for 77 young adults (Experiment 1). Naming ability decreases in normal and pathological aging. Therefore, norms were also derived for older adults (Experiment 2) and for probable Alzheimer's disease patients (Experiment 3). With respect to the young adults, perseverative naming behavior increased in these groups, and sound and picture naming performance were correlated. In Experiment 4, the sound-naming performance of children aged 5-6, 9-11, and 14-16 years was compared. Name and conceptual agreements improved with age, whereas perseverative behavior decreased. These normative data should be useful in guiding sound selection in future studies and help clarify the relationships between sound naming and other variables, including direct and indirect memory performance.
Acoustic Stimulation↗
An ERP developmental study of repetition priming by auditory novel stimuli.
Event-related potentials were recorded from participants 5-7, 9-11, 14-16, and 22-28 years old during an auditory novelty oddball task. In this task, stimuli about which the participant is not instructed (i.e., novel or uncategorized) typically elicit a more frontally oriented P3 scalp topography (novelty P3). In contrast, stimuli to which the participant must respond (i.e., target or precategorized) elicit a P3 with a more posterior scalp topography. Repetition of identical novel stimuli led to a similar reduction in novelty P3 amplitude for all age groups. Moreover, with repetition the shift in scalp topography of the novelty P3 to a more parietally oriented distribution was similar in children and adults. A second component, the P3(2) (assumed to be an analog of the P3b), exhibited a repetition priming effect in both the adults and the youngest children. The fact that age-related differences induced by novel repetition were small and not systematic indicates that the processing of novel information is similar across a wide age range.
Acoustic Stimulation↗
[Pregnancy after surgical therapy of obesity. Bibliographic review and our experience with biliopancreatic diversion].
BACKGROUND: An increasing number of women in childbearing age are submitted to surgical treatment of obesity; for this reason pregnancy represents a frequent event in operated patients. METHODS: In this study pregnancy in patients with morbid obesity submitted to jejunoileal bypass (JIB) and gastric bypass (GB) are reviewed from the literature and the analysis of our experience with biliopancreatic diversion (BPD) is reported. RESULTS: In 113 pregnancies after JIB reviewed from the literature, the results seem to be debated either about the course of pregnancy or about maternal and neonatal status. The data of literature concerning the pregnancies following GB are less debated but rather slight. One hundred and fifty-two pregnancies after BPD have a complete documentation concerning maternal conditions, modality of outcome and neonatal situation. CONCLUSIONS: Pregnancy occurred in the obese women represents an increased maternal-fetal risk. The excess weight loss, the weight maintenance and the reduced weight changes during pregnancy are an advantage in the operate women who, in any case, need accurate controls of the nutritional status during the whole gestational period. Keeping these cautions pregnancy following surgical treatment of obesity represents an event not only possible but even with less problems than in pregnancy in obese women.
Adult↗
Preliminary observations on the use of midodrine in treating orthostatic hypotension in familial dysautonomia.
Midodrine, a peripheral alpha-adrenergic agonist, was evaluated in 7 female and 2 male patients with familial dysautonomia (FD), a disorder characterized by decreased sympathetic innervation. Prior to and after three months of midodrine treatment, each patient's response to postural change was assessed by arteriosonde readings of blood pressure and heart rate, corrected QT-interval measurements, Doppler evaluation of renal blood flow and circulating atrial natriuretic peptide (ANP) levels. The initial midodrine dose (2.5 mg three times daily) was raised until subjective symptoms improved. Doses were reduced if patients felt jittery or developed erect hypertension (systolic > 180 mmHg or diastolic > 110 mmHg). Midodrine, at an average dose of 0.25 mg/kg per day, improved subjective symptoms in all patients. With treatment, magnitude of blood pressure responses was variable. Although mean erect blood pressure did not increase significantly for the aggregate, it did increase in six of nine patients. In addition, the QTc interval normalized and erect renal perfusion improved. Changes in supine mean blood pressure and supine circulating ANP correlated directly. We judge midodrine to be useful in management of orthostatic hypotension in patients with familial dysautonomia.
Adolescent↗
Event-related potential and behavioral correlates of semantic processing in Alzheimer's patients and normal controls.
In normal young adults, N400 amplitude varies inversely with the extent to which a word has been primed by its preceding semantic context. Based on a series of behavioral studies, it appears that in Probable Alzheimer's patients (PAD) the organization of semantic memory is disrupted such that specific items within a category lose their distinction, although superordinate information remains relatively intact. The present study examined whether the N400 gradient which has been found with normal young adults would also reflect this loss of discriminability among semantically related items in PAD patients. Ten normal young adults, 10 normal elderly, and 6 "mild" PAD patients made speeded (but accurate) sense/nonsense decisions to the terminal words of a series of highly constrained sentence contexts. The terminal words belonged to one of four stimulus types which varied as a function of relatedness to a highly expected word. Counter to our predictions, N400 amplitude was identically responsive to semantic relatedness in the young normal and PAD groups, but was characterized differently in the normal elderly. Given the significantly greater number of errors committed by PAD patients, we concluded that their disruption in semantic processing occurs at some point between the elicitation of N400 and the generation of the reaction time response. The anomalous N400 pattern in the normal elderly appeared to be strategy related and superimposed upon an otherwise normal semantic network.
Adult↗
The development of selective attention as reflected by event-related brain potentials.
The development of auditory selective attention was assessed using event-related brain potentials (ERPs) and behavioral measures, with children (mean age = 8.1), adolescents (14.4), and young adults (23.8) as subjects. During separate blocks, subjects heard two sequences of pure tones (low- and high-pitched) or consonant-vowels (CVs; for example, ba vs da). Subjects were required to attend to one of the two stimuli in order to detect a deviant target embedded within the attended sequence, while ignoring the sequence comprised of the other stimulus (which also contained standard and deviant stimuli). The frequent standards were always 100 ms in duration, whereas the infrequent targets were of longer duration. The effect of selective attention was operationalized by computing the Nd difference waveform (ERP elicited by the unattended standard subtracted from that elicited by the attended standard). There was an increase in early Nd amplitude (measured from about 200 to 400 ms) and a decrease in its latency for both pure tones and CVs from childhood through young adulthood. For the amplitude measure, this effect was much more marked for CVs. Additional analyses indicated that the major effect of age involved reduction of negative-going ERP amplitude elicited by stimuli in the unattended channel, suggesting that with age there is an improvement in the narrowing of the attentional focus, with the major change taking the form of greater facility in rejecting stimuli in the unattended channel. Age-related shifts in scalp distribution of both early and late Nd were seen as consistent with, respectively, age-related changes in the way attention was allocated to the two input channels, and in the way in which the attentional trace was maintained by selective rehearsal.
Adolescent↗
Children who are shot: a 30-year experience.
Three data sets describe the pattern of gunshot injuries to children from 1960 to 1993: The Harlem Hospital pediatric trauma registry (HHPTR), the northern Manhattan injury surveillance system (NMISS) a population-based study, and the National Pediatric Trauma Registry (NPTR). A small case-control study compares the characteristics of injured children with a control group. Before 1970 gunshot injuries to Harlem children were rare. In 1971 an initial rise in pediatric gunshot admissions occurred, and by 1988 pediatric gunshot injuries at Harlem Hospital had peaked at 33. Population-based data through NMISS showed that the gunshot rate for Central Harlem children 10 to 16 years of age rose from 64.6 per 100,000 in 1986 to 267.6 per 100,000 in 1987, a 400% increase. The case fatality for children admitted to Harlem Hospital (1960 to 1993) was 3%, usually because of brain injury, but the majority of deaths occurred before hospitalization. During the same period, felony drug arrests in Harlem increased by 163%. The neighboring South Bronx experienced the same increase in gunshot wound admissions and felony arrests from 1986 to 1993. The NPTR showed a similar injury pattern for other communities in the United States. In a case-control analysis. Harlem adolescents who had sustained gunshot wounds were more likely to have dropped out of school, to have lived in a household without a biological parent, to have experienced parental death, and to have known of a relative or friend who had been shot than community adolescents treated for other medical or surgical problems.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Primary omental torsion in children.
Primary torsion of the omentum is an unusual cause of an acute abdomen and commonly mimics acute appendicitis. The following report of four obese children is supportive of obesity as a predisposing factor. The paucity of gastrointestinal symptoms, anorexia, nausea, vomiting, and the relatively long duration of symptoms, may increase the index of suspicion. In the majority of cases, the diagnosis is made intraoperatively by digital exploration through the muscle-splitting incision. The torsed omentum is easily delivered through the same incision, and excision results in complete recovery.
Adolescent↗
Pupillary and visual thresholds in young children as an index of population vitamin A status.
A prototype scotopic sensitivity machine was used to evaluate pupillary and visual thresholds for 295 Indonesian children aged 1-5 y, most of whom were initially vitamin A-deficient. Subjects were tested 6 and 9 mo after receiving a high dose of vitamin A. A group of 136 older children was tested at 6 mo after dosing; all subjects underwent testing at 9 mo. After testing at 9 mo, children randomly received either a second high dose of vitamin A or placebo and were tested a final time 2 wk later. Children with abnormal pupillary thresholds had significantly higher relative dose responses (RDRs) (P < 0.01) and significantly lower serum retinol values (P = 0.05) than did normal children. The mean pupillary threshold rose (eg, retinal sensitivity fell) as vitamin A status deteriorated between 6 and 9 mo after initial dosing, and was significantly different from a group of normal American children tested previously (P < 0.001). After placebo-controlled dosing, the decline in pupillary and visual thresholds (rise in retinal sensitivity) was significant for children receiving vitamin A but not for children receiving placebo.
Aging↗
Changes in brain activity patterns in aging: the novelty oddball.
A decrease in the frontal lobes' efficiency is supposed to play a role in age-related changes in cognitive function. If frontal lobes are involved in the maintenance of working memory, the elderly may require increased frontal activity because of more rapid memory decay. This is consistent with the fact that the P3 component of the event-related potential (ERP) has a more frontal orientation with increasing age. However, frontally distributed P3s are also observed in young people when novel stimuli are unexpectedly presented in an oddball paradigm. Young and old subjects were run in an auditory novelty oddball in which ERPs were recorded from 30 scalp sites. The young adults' P3s showed either a posterior (targets) or more frontally oriented (novels) scalp focus. The elderly were less accurate in their memory for the novel stimuli, and their P3s showed anterior and posterior foci to both targets and novels. The young adults' target P3s changed over time from a frontal to a posterior focus, whereas the old adults' did not. These results are consistent with decreased ability of the elderly to maintain the templates needed for stimulus categorization.
Adult↗