General practitioner maternity units.
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Family Practice↗
Biomedical subjects
R Campbell
Publications and source records attributed to R Campbell.
Deafness and immediate memory for pictures: dissociations between "inner speech" and the "inner ear"?
Born-deaf, orally trained youngsters were examined on two tasks of immediate memory for pictures of objects. The aim was to investigate the extent of speech coding for pictures in immediate memory in a developmental context. The deaf, unlike young hearing children, did not use picture-name rhyme spontaneously as a cue to recall in a paired association task. Nevertheless, they were just as sensitive as reading age-matched hearing controls to spoken word length in recalling pictures by name. This might mean that the deaf use articulatory rehearsal in some immediate memory tasks, but this leads to a paradoxical conclusion. What could "inner speech" in the deaf be for, if it fails to affect their "inner ear" by inducing rhyme sensitivity in the paired associate task? This paradox is discussed in relation to distinctions between covert and overt use of memory cues in the paired recall task and to possible sources of the word length effect in young hearing (8-9 years old) and deaf subjects.
Adolescent↗
Neuropsychological studies of auditory-visual fusion illusions. Four case studies and their implications.
A heard speech sound which is not the same as the synchronized speech sound can sometimes give rise to an illusory phonological percept. Typically, a heard /ba/ combines with a seen /ga/ to give the impression that /da/ has been heard (McGurk, H. and MacDonald, J. Nature Lond. 264, 746-748, 1976). We report the susceptibility to this illusion of four individuals with localized brain lesions affecting perceptual function. We compare their performance to that of ten control subjects and relate these findings to the efficiency of processing seen and heard speech in separate and combined modalities. The pattern of performance strongly suggests LH specialization for the phonological integration of seen and heard speech. The putative site of such integration can be effectively isolated from unilateral and from bilateral inputs and may be driven by either modality.
Adult↗
Sensitivity to eye gaze in prosopagnosic patients and monkeys with superior temporal sulcus ablation.
Accuracy at perceiving frontal eye gaze was studied in monkeys and human subjects using a forced-choice detection task on paired photographs of a single human face. Monkeys learned the task readily, but after bilateral removal of the banks and floor of the superior temporal sulcus (STS) they failed to perform the task efficiently. This result is consistent with the conclusion, based on recordings from single cells in awake, behaving monkeys [Perret et al., Physiological Aspects of Clinical Neuro-ophthalmology, Chapman & Hall, London, 1988] that this region of the temporal lobe is important for coding information about eye-gaze of a confronting animal. Human subjects were given identical stimuli in a task where they were asked to detect "the face that is looking straight at you". Human performance is sensitive to the degree of angular deviation from the frontal gaze position, being poorest at small angular deviations from 0 degrees. This was also true of monkeys viewing these stimuli, pre- and post-operatively. Compared with normal controls, two humans prosopagnosics were impaired at this task. However the extent of impairment was different in the two patients. These findings are related to earlier reports (including those for patients with right-hemisphere damage without prosopagnosia), to normal performance with upright and inverted face photographs, and to notions of independent subsystems in face processing.
Adult↗
Opioid control of growth hormone in the suckled sow is primarily mediated through growth hormone releasing factor.
Endogenous opioid peptides mediate the effect of suckling on LH and PRL in the domestic pig. However, the role of opioids in modulating GH during lactation in swine is not known. Primiparous sows that had been immunized against GRF(1-29) conjugated to human serum albumin (GRF-HSA, n = 5) or HSA (n = 4) were used to determine changes in GH after naloxone. Treatments were imposed in all sows on day 21 of lactation when antibody titers were 9100 +/- 1629. All sows received (i.v.) naloxone (0.25 mg/kg) or saline (0.0125 ml/kg) at 15 min intervals for 165 min. Active immunization against GRF-HSA during lactation decreased (P less than 0.05) mean concentration (4.8 +/- 0.2 vs 2.6 +/- 0.1 ng/ml) and frequency (1.5 +/- 0.3 vs 0.4 +/- 0.2 peaks/4 hr). Concentrations of LH and PRL were similar in GRF-HSA and HSA immunized sows. Naloxone suppressed (P less than 0.05) GH in all sows. In HSA sows, naloxone abolished episodic release of GH and decreased average, but not basal, concentrations of GH. In sows immunized against GRF-HSA, naloxone decreased (P less than 0.05) average and basal GH but failed to decrease frequency of GH release. Naloxone failed to alter frequency of LH release. Concentrations of PRL decreased (P less than 0.05) after naloxone in all sows. In conclusion, immunization against GRF-HSA blocked most of the effect of lactation on GH. Blocking opioid receptors with naloxone decreased GH and PRL in all sows. In contrast to previous findings naloxone had no effect on LH. Opioids alter concentrations of GH through a GRF dependent and GRF independent pathway.
Animals↗
Learning a unimanual motor skill by partial commissurotomy patients.
A series of motor tests on four Chinese partial commissurotomy patients is reported. The single-stage commissurotomy in all four patients included the anterior commissures and two-thirds or four-fifths section of the corpus callosum with sparing of the splenium. There was no demonstrable ability to transfer hand posture in these patients. This was the major evidence for functional deconnexion. A newly learned task of one-hand knotting revealed right hand impairment in all four patients. There was no dyspraxia in the right hand for over-learned object-handling tasks in these patients. It is suggested that there might be right hemisphere specialisation for the initial acquisition of unimanual object-handling skills and that the spared callosal fibres in the splenium alone are insufficient to mediate task control under these conditions. This is supported by the finding that one of these patients, who was the only one who had a right parietal lesion, was unable to perform the newly learned task with either hand.
Adolescent↗
Toxoplasmosis of the conus medullaris in a patient with hemophilia A-associated AIDS. Case report.
Toxoplasma gondii has been reported to be the most common cause of focal brain lesions in patients with acquired immunodeficiency syndrome (AIDS). A case of intramedullary toxoplasmosis of the conus medullaris is reported in a patient with hemophilia A-associated AIDS. The diagnosis is discussed, with particular emphasis on the magnetic resonance imaging appearance.
Acquired Immunodeficiency Syndrome↗
Laboratory and clinical evaluation of the MAX transport ventilator.
UNLABELLED: Transport of critically ill, mechanically ventilated patients from intensive care units for diagnostic and therapeutic procedures has become common in the last decade. Maintenance of adequate oxygenation and ventilation during transport is mandatory. We evaluated the Hamilton MAX transport ventilator in the laboratory and in the clinical arena to determine its usefulness during in-hospital transport. METHODS: In the laboratory, we determined the MAX's ability to assure tidal volume (VT) delivery in the face of decreasing compliance of a test lung, and we tested the alarm system. Using a two-compartment lung model modified to simulate spontaneous breathing, we also evaluated the responsiveness of the demand valve. The clinical evaluation was accomplished by comparing arterial blood gases and ventilator settings in the intensive care unit to those during transport. RESULTS: As lung compliance was reduced from 0.1 to 0.02 L/cm H2O [1.0 to 0.20 L/kPa], delivered VT fell significantly at each set VT. The alarm systems performed according to manufacturer's specifications. The demand valve triggered appropriately without positive end-expiratory pressure (PEEP), but as PEEP was increased, triggering became more difficult. The demand valve is referenced to ambient pressure and cannot compensate for elevated end-expiratory pressures. During patient transport, arterial blood gases were comparable to those achieved in the ICU. Because an inspired oxygen concentration of 1.0 was used during transport, arterial oxygenation (PaO2) was significantly greater (123 +/- 75 vs 402 +/- 85 torr [16.4 +/- 10 vs 53.6 +/- 11 kPa]). A higher ventilator rate was required during transport to prevent tachypnea (7 +/- 3 vs 12 +/- 6 breaths/min), and peak inspiratory pressure (PIP) was higher during transport (40 +/- 8 vs 52 +/- 11 cm H2O [3.9 +/- 0.8 vs 5.1 +/- 1.1 kPa]). CONCLUSIONS: The MAX is a reliable transport ventilator, capable of maintaining adequate ventilation and oxygenation in a majority of mechanically ventilated patients. Care should be taken to assure adequate VT delivery at high PIP, and ventilator rate may require adjustment to prevent tachypnea associated with triggering the non-PEEP-compensated demand valve when PEEP greater than 8 cm H2O [0.8 kPa] is used.
Adult↗
Survival after blunt traumatic rupture of the left ventricle.
There have been 11 reported survivors from blunt-trauma-induced right ventricular rupture and only three from left ventricular rupture. We report the fourth case of a survivor of blunt left ventricular rupture. This patient presented with hypotension from both hemorrhage into the left chest and pericardial tamponade. The tamponade was relieved via an emergent left thoracotomy, the bleeding from the rent in the left ventricle was easily controlled, and repair was straightforward.
Adult↗
Neuropathological abnormalities in developmental dysphasia.
The brain of a 7-year-old girl with developmental dysphasia who died of complications of infectious mononucleosis was examined grossly and histologically. The neuropathological studies revealed atypical symmetry of the plana temporale and a dysplastic gyrus on the inferior surface of the left frontal cortex along the inferior surface of the sylvian fissure. These anomalies are likely related to midgestation, the period of neuronal migration from the germinal matrix to the cerebral cortex, and are consistent with a neurodevelopmental cause of developmental dysphasia.
Aphasia↗
The early and late responses of the arterial wall to graft placement.
The relationship between the early smooth muscle cell proliferative response (SMC-PR) to injury and the later development of myointimal hyperplasia (MIH) complicating arterial bypass grafts remains unclear. In the present study, the early SMC-PR and the later MIH induced by a 2-mm-diameter PTFE graft placed in a rabbit carotid were compared with the response induced by an autogenous artery (AA) graft in the contralateral carotid. The early SMC-PR was measured in the proximal and distal arterial segments 5 days after graft placement by in vivo labeling with [3H]thymidine to determine the DNA specific activity (DNA-SA). The later anastomotic MIH was measured 16 and 32 weeks postgrafting by calculating the intimal/medial ratio. There was a marked and similar increase in the early SMC-PR noted with both the AA and the polytetrafluoroethylene (PTFE) grafts. The distal segments demonstrated a significantly higher DNA-SA when compared to the proximal in both AA- and PTFE-grafted arteries. There was a moderate degree of anastomotic MIH noted in chronic grafts; however, a regression in intimal thickening was observed over time in the AA-grafted arteries, while the distal anastomosis of the PTFE-grafted vessels demonstrated a continuous progression of the MIH process. The early SMC-PR may abate in arteries grafted with autogenous grafts, but there is a persistent proliferative response at the distal anastomosis associated with synthetic grafts.
Animals↗
Solar and UVC-induced mutation in human cells and inhibition by deoxynucleosides.
Optimum conditions were established for quantitating the induction of hypoxanthine guanine phosphoribosyl transferase-deficient (HGPRT-) mutants in HeLa cells and in a human amelanotic melanoma cell line (MM96L). Compared at a fluence of equal toxicity (D37, fluence required to decrease cell survival to 37% of unirradiated control), noon sunlight in summer was slightly more mutagenic in MM96L than in HeLa cells (17 and 12 HGPRT- mutants per 10(6) survivors respectively). UVC (predominantly 254 nm) exhibited similar mutagenicity as equitoxic sunlight in HeLa but was 8-fold more effective in MM96L than equitoxic sunlight. Addition of a mixture of deoxyguanosine (20 microM), deoxyadenosine (20 microM), deoxycytidine (100 microM) and thymidine (20 microM) to the culture medium during the 7-day expression period following irradiation gave a 3-fold reduction in the UVC-induced mutation frequency of MM96L but not HeLa cells. The results suggest that these melanocytic cells are highly susceptible to mutagenesis by short wavelength UV, in a mechanism sensitive to deoxynucleosides.
DNA Damage↗
Cellular mosaicism in the methylation and expression of hemizygous loci in the mouse.
Proposed models for the inheritance of locus-specific methylation phenotypes in somatic cells include those in which there is stable inheritance of a methylation pattern such that all cells contain a similarly methylated locus, as well as models in which the inheritance of methylation can be variable. We investigated these possibilities by examining the methylation and expression of hemizygous loci in the mouse. Our results demonstrate that differences in both methylation and expression can exist between apparently identical cells and that such mosaicism is genetically controlled.
Animals↗
Immediate memory in the orally trained deaf: effects of 'lipreadability' in the recall of written syllables.
Immediate recall of written lists was compared in strictly orally trained born-deaf teenagers and in hearing controls. The lists were of syllables of CV form (e.g. SHA NA ZA DA). The deaf subjects showed a significant effect of consonant 'lipreadability'. Syllable lists containing consonants like D, SH and Z whose place of articulation is not visibly distinctive and which are therefore hard to lipread are less well recalled than (phonetically and orthographically matched) syllable lists containing consonants like F, TH and B which are produced with the tongue, teeth and lips in visible configuration. We conclude that for these deaf youngsters the phonological representation of written consonants is less secure for speech sounds that are hard, rather than easy, to lipread. The oral training of these youngsters has had an effect on their internal representation of written speech. Hearing subjects showed no 'lipreadability' effect in their recall of these lists. Reading-age matched controls (aged 8-10 years) showed significantly shorter span for both list types than the deaf group. Older hearing controls (14-16 years) matched the deaf group in span and tended to recall most accurately written syllables which are not easily lipread. We discuss these comparisons and conclude that while this group of deaf subjects is using a phonological code in the recall of written syllables, it is qualitatively different from that used by hearing subjects in this task. In particular, not only hard-to-lipread consonants but also vowels may be less strongly represented in these deaf readers' 'inner voice'.
Adolescent↗
Effectiveness of writing groups in nursing homes.
We examine the effect of participation in an 8-week writing group in six nursing homes. Pretest and posttest assessments of cognitive and affective functional status were administered to 62 participants and 54 control subjects. We asked writing-group participants about previous writing experience and perceived ability to convey feelings, ideas, life experiences, and memories to others. Weekly assessments were conducted on eight group process measures. Findings suggest that participation in writing groups may reduce depression, particularly among residents with higher cognitive ability and greater depression. Significantly more participants than control subjects report an ability to relate feelings and ideas to other residents and staff. Improvement in group process measures is greatest for cognitively impaired participants and those with high physical function scores. There is considerable improvement in residents for whom writing-group participation frequently is considered inappropriate: those without writing experience, the depressed, and the cognitively impaired.
Aged↗
An animal model for small-diameter arterial grafts.
A rabbit model was developed to study small-diameter arterial grafts. A total of 158 2-mm-diameter polytetrafluoroethylene (PTFE) grafts and 35 autogenous carotid artery (AA) grafts were interposed in the carotid arteries of New Zealand white rabbits. A pilot study of 16 PTFE grafts used to develop operative and anesthetic techniques had a 20% mortality and 38% early (less than 2 day) thrombosis rate. Subsequent to the pilot study 177 grafts were placed and a 92% postoperative survival with 100% AA graft patency and 93% PTFE graft patency at 2 weeks was observed. AA grafts followed beyond 16 weeks continued to have 100% patency, while PTFE grafts began to show increased failure. Closure was found to be due to the development of anastomotic myointimal hyperplasia.
Animals↗
Michigan doctor encourages children to plant trees, help environment.
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Child↗
A transgene containing lacZ inserted into the dystonia locus is expressed in neural tube.
The site of integration of transgenes in the host genome can affect levels of expression and occasionally confer ectopic patterns of expression on otherwise tissue-specific genes. We describe here a line of mice in which an hsp68-lacZ transgene is expressed in unstressed developing neural tissue and where the transgene insertion has caused a mutation of a neural tissue-specific gene, dystonia musculorum (dt). This coincidence suggests that expression of the hsp68-lacZ construct may be controlled directly by cis-acting regulatory sequences that normally control the developmental expression of the dt gene. Such constructs may serve as useful tools for identifying new tissue-specific enhancers and their associated genes.
Animals↗