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Biomedical subjects

M Barr

Publications and source records attributed to M Barr.

At least 19 recordsLinked to original sources
PubMed1992

Cervical spine in the Apert syndrome.

Radiographs of the cervical spine--in many cases longitudinal--were available for study in 68 cases of Apert syndrome. Autopsy material was available in one of these cases, and a 3-dimensional reconstruction from a CT scan was also studied in one case. Variable degrees of fusion were observed, involving the articular facets, the neural arch or transverse processes, or block fusion of the vertebral bodies. Ossification may not always be evident in some early radiographs. However, early radiographic signs of impending fusion may be irregularity in vertical orientation of the vertebral bodies and narrowing of the involved intervertebral spaces. Cervical fusions occurred in 68%, single fusions being found in 37%, and multiple fusions in 31%. C5-C6 fusion was most common, alone or in combination with other fusions. In contrast, cervical fusions are known to occur in 25% of Crouzon patients, most commonly involving C2-C3 only. It appears that when fusions are present, C5-C6 involvement in the Apert syndrome and C2-C3 involvement in the Crouzon syndrome separate the 2 conditions in most cases. Because cervical anomalies may complicate an already compromised airway in any form of acrocephalosyndactyly, it is imperative to initiate radiographic study of the cervical spine before undertaking anesthesia for surgery.

Acrocephalosyndactylia↗
PubMed1992

Expression of four protein kinase C isoforms in rat fibroblasts. Differential alterations in ras-, src-, and fos-transformed cells.

In the accompanying study (Borner, C.B., Guadagno, S. N., and Weinstein, I. B. (1992) J. Biol. Chem. 267, 12892-12899) we found that R6 embryo fibroblasts express four isoforms of PKC, cPKC alpha, nPKC epsilon, nPKC delta, and nPKC zeta whose subcellular distribution, activation, and down-regulation are differentially regulated. Furthermore, we demonstrated that overproduction of an exogenous cPKC beta I isoform in these cells (R6-PKC3) altered the TPA-induced down-regulation of nPKC delta and nPKC epsilon. In this paper we show that transformation of R6 or R6-PKC3 cells with a variety of different oncogenes results in differential alterations in expression of individual PKC isoforms. R6 or R6-PKC3 cells transformed by an activated c-H-ras oncogene displayed a marked increase in the expression of both cPKC alpha and nPKC delta, decreased expression of nPKC epsilon, and no change in the expression of nPKC zeta. These alterations occurred at both the mRNA and protein levels but did not significantly affect the subcellular distribution of any of the four isoforms. Studies using actinomycin D and nuclear run-off assays indicated that the increased expression of cPKC alpha in ras-transformed cells was due to increased de novo transcription rather than increased mRNA stability. Qualitatively similar, but less extensive changes in the expression of the four PKC isoforms were seen in v-fos-transformed R6-PKC3 cells. Decreased expression of nPKC epsilon was also seen in the v-src-transformed R6- and R6-PKC3 lines; however, the cellular level of cPKC beta I appeared to be a limiting factor in mediating the effects of v-src on the increased expression of cPKC alpha and nPKC delta. Interestingly, no major changes in the levels of expression of any of the four PKC isoforms were found when R6 cells were transformed by myc, neu/erb-B2, or mos oncogenes. These results demonstrate that transformation of R6 cells by the oncogenes ras, src, and fos differentially alter the expression of three isoforms of PKC in the same host cell, and they suggest that individual isoforms may play distinct roles in mediating cellular transformation by specific oncogenes.

Alkaloids↗
PubMed1992

Effect of ACE inhibition on the fetal kidney: decreased renal blood flow.

The kidneys of nine fetuses whose mothers were chronically hypertensive were examined microscopically. Three of these mothers used antihypertensive agents throughout pregnancy including one who used an angiotensin-converting enzyme (ACE) inhibitor. The tubular defects found in these kidneys were compared to the kidneys of 20 normal controls, 13 fetuses with various multiple malformation syndromes and six cases of the twin to twin transfusion syndrome. Evidence from these cases as well as the literature suggest that the primary mechanism by which ACE inhibitors affect development of the fetal kidney is through decreased renal blood flow.

Abnormalities, Drug-Induced↗
PubMed1992

A four-year follow-up of hearing and development in children exposed in utero to vibro-acoustic stimulation.

OBJECTIVE: To obtain information of hearing and neuro-development in children exposed to vibro-acoustic stimulation in utero. DESIGN: Information collected from Swedish child care programmes. SETTING: Department of Obstetrics and Gynaecology, Karolinska Institutet, Danderyd University Hospital, Sweden. SUBJECTS: Children of 460 mothers exposed to vibro-acoustic stimulation for the assessment of fetal well-being during high- and low-risk pregnancies during 1985-1987. MAIN OUTCOME MEASURES: Auditory test (20-25 dB at eight frequencies between 500 and 8000 Hz) and general neurological examination at four years of age. RESULTS: No hearing damage or neuro-developmental abnormalities that could be connected to the vibro-acoustic stimulation were found. CONCLUSIONS: Vibro-acoustic stimulation, as applied in clinical practice, did not endanger either neurological development or hearing in children exposed in utero.

Acoustic Stimulation↗
PubMed1992

Spontaneous resolution of nonimmune hydrops fetalis secondary to human parvovirus B19 infection.

Many instances of nonimmune hydrops fetalis ascribed to human parvovirus B19 have been reported. The leading proposed pathophysiologic mechanism of hydrops in affected fetuses is viral invasion of red blood cell progenitors, causing a profound reticulocytopenic fetal anemia. Although the natural history of fetal parvovirus infection remains to be elucidated fully, there have been recent reports of funipuncuture and intrauterine blood transfusions to diagnose and manage this problem. We report two pregnancies in which parvovirus-related hydrops fetalis was observed to resolve without intervention, followed by uncomplicated vaginal deliveries of healthy infants. These observations emphasize the need for further investigation before recommending routine fetal blood transfusion in affected cases.

Adolescent↗
PubMed1991

ACE inhibitor fetopathy and hypocalvaria: the kidney-skull connection.

Two cases of angiotensin converting enzyme inhibitor fetopathy with renal tubular dysgenesis and severely underdeveloped calvarial bone are described. Six additional, unexposed cases of hypocalvaria are described, and possible links between calvarial development and fetal hypotension and/or chronic hypoxia are explored.

Abnormalities, Drug-Induced↗
PubMed1991

Renal obstructive dysplasia: ultrasound diagnosis and therapeutic implications.

57 cases of renal obstructive dysplasia (defined as the abnormal development of nephronic and ductal structures due to in utero obstruction of the urinary tract) were evaluated in terms of sonographic findings, renal and other associated anomalies, and current status of the child. More than one-third of the cases had bilateral disease and although not uniformly fatal bilateral involvement was associated with significant morbidity and mortality. In 12 of the 33 cases with unilateral dysplasia there was an association with contralateral renal problems including uretero-pelvic junction obstruction, vesicoureteral reflux and aplasia. Almost one-half of the cases had congenital anomalies, these included VACTERL association, congenital heart disease, cranial abnormalities and gastrointestinal malformations. Fifteen stillborns and 12 of the patients with bilateral involvement and four with unilateral involvement have died. Four patients are on dialysis (two with bilateral involvement and two with unilateral renal obstructive dysplasia). Only one-quarter are otherwise normal. More serious problems are reported in this mixed age population of patients with obstructive renal dysplasia than has been identified in previous studies. Management decisions of the fetus and child must be based on this new age-expanded population.

Abnormalities, Multiple↗
PubMed1991

Records. Rights of access.

From 1 November 1991 clients will have right of access to their health records. Health visitor journal outlines the provisions of the Access to Health Records Act 1990; HVA professional officer Jane Naish examines the implications for health visitor and school nurse practice, and solicitor Melanie Barr describes the legal context.

Community Health Nursing↗
PubMed1979

Feingold diet.

Explore the source record for details and available documents.

Child↗