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Biomedical subjects

J Bruce

Publications and source records attributed to J Bruce.

At least 145 records · Page 8Linked to original sources
PubMed1991

Timing of surgery in congenital diaphragmatic hernia. Low mortality after pre-operative stabilisation.

Eighty-six consecutive patients with congenital diaphragmatic hernia presenting within 6 hours of birth to a regional neonatal surgical unit were reviewed. Patients were managed under a policy of delayed surgery which has evolved during the 6-year study period. Overall survival (to leave hospital) was 70.9%. There were only seven postoperative deaths (10.3% of operations). Analysis of the 25 deaths in the light of postmortem findings and published exclusion criteria indicates that the availability of extracorporeal membrane oxygenation would have made little difference to overall survival.

Emergencies↗
PubMed1991

Long-term follow-up of children with testicular tumours: surgical issues.

Testicular tumours are rare in childhood. The clinical, pathological and follow-up details of 48 children are presented. The combined approach of surgery, chemotherapy and radiotherapy is confirmed as being extremely effective. Transcrotal orchiectomy is not an appropriate surgical procedure. Testicular biopsy is detrimental to prognosis.

Child, Preschool↗
PubMed1991

Sequential cerebrospinal fluid and plasma sampling in humans: 24-hour melatonin measurements in normal subjects and after peripheral sympathectomy.

Simultaneous measurements of plasma and cerebrospinal fluid (CSF) melatonin and urinary excretion of 6-hydroxymelatonin were performed in four normal volunteers and one patient before and after upper thoracic sympathectomy for the control of essential hyperhidrosis. For normal individuals, hourly 24-h melatonin concentrations in plasma and CSF exhibited similar profiles, with low levels during the day and high levels at night. Peak plasma levels varied from 122-660 pmol/L, and the peak CSF levels from 94-355 pmol/L. The onset of the nocturnal increase in melatonin did not occur at the same time for each individual. Urinary 6-hydroxymelatonin levels also exhibited a daily rhythm, with peak excretion at night. The individual with the lowest nocturnal levels of circulating melatonin also had the lowest excretion of 6-hydroxymelatonin. In the patient with hyperhidrosis, a prominent melatonin rhythm was observed preoperatively in the CSF and plasma. After bilateral T1-T2 ganglionectomy, however, melatonin levels were markedly reduced, and the diurnal rhythm was abolished. These results provide direct evidence in humans for a diurnal melatonin rhythm in CSF and plasma as well as regulation of this rhythm by sympathetic innervation.

Adult↗
PubMed1990

Simultaneous up-regulation of neurofilament proteins during the postnatal development of the rat nervous system.

The expression of neurofilament (NF) proteins was examined during postnatal development of the rat nervous system in order to elucidate the nature of NF expression during the period of transition from the embryonic (immature) to the adult (mature) stages of NF expression. mRNAs to the light (NF-L), mid-sized (NF-M), and heavy (NF-H) NF proteins were compared by Northern blots and by in situ hybridizations, in NF-rich (i.e., DRG, spinal cord and brainstem) and in NF-poor (i.e., cerebellum and cerebral cortex) regions of the developing rat nervous system. NF proteins were analyzed by gel electrophoresis and by immunoblots. In each tissue, the expression of NF-H was delayed compared to that of NF-L and NF-M, as previously reported. The present study now shows that the delayed expression of NF-H is accompanied by parallel up-regulations in the expressions of NF-L and NF-M, both at the levels of mRNA and protein. Similar rates of increase of all three NF mRNAs occur between postnatal days 5 (P5) and 24 (P24) in rat spinal cord and DRG. Furthermore, the postnatal up-regulation of NF expression is characterized by a progressive accumulation of all three NF proteins in the tissues. The findings indicate that the adult pattern of NF expression (with high levels of expression of all three NF proteins) becomes established during the postnatal period of development, raising questions as to the nature of factors that coregulate the expression of NF subunits.

Aging↗
PubMed1990

Axonal dependency of the postnatal upregulation in neurofilament expression.

A coordinated up-regulation in the expression of all three neurofilament (NF) proteins occurs during postnatal development in the rat (Schlaepfer and Bruce, J Neurosci Res [in press], 1990a). In the present study, sciatic nerves were transected in neonatal rats in order to determine the effects of axotomy on the postnatal upregulation of NF expression in neurons of rat dorsal root ganglia (DRG). Left sciatic nerves were transected at postnatal day 3 (P3), 6 (P6), 8 (P8), or 10 (P10). mRNA and protein levels of the light (NF-L), mid-sized (NF-M), and heavy (NF-H) NF proteins were compared in L4 and L5 DRGs from the transected (left) vs. control (right) sides of the same animals at varying intervals after transection. When nerves were transected at P10, mRNA levels of all three NF proteins declined markedly in the parent DRG neurons, thereby completely interrupting the postnatal upregulation of NF expression. P10 transections also led to widespread chromatolytic changes in axotomized neurons, indistinguishable from those that occur in adult DRG following sciatic nerve transection (Goldstein et al., J Neurosci 7:1586-1594, 1987). Nerve transections at earlier (e.g., P3) neonatal timepoints also led to a decrease of NF expression, but to a lesser extent than that which resulted from a P10 transection. Also, P3 transections caused only minimal chromatolytic changes in the axotomized neurons. Thus, the postnatal upregulation of NF expression is dependent upon axonal continuity and the extent of axonal dependency increases during early postnatal development. These findings support the hypothesis that the postnatal upregulation of NF expression, the axotomy-induced downregulation of NF expression and the chromatolytic reaction to nerve transection are all dependent upon or responsive to axonal- or target cell-derived signals that are acquired during postnatal maturation.

Animals↗
PubMed1990

Long-term follow-up of children with renal carcinoma.

Renal carcinoma is a rare tumour in children. The clinical, histological and follow-up details of 6 patients are presented. Haematuria is confirmed as an important indicator of renal pathology. Long-term follow-up suggests that chemotherapy and radiotherapy have little effect on the prognosis in advanced disease.

Adolescent↗
PubMed1990

Neurofilament proteins are distributed in a diminishing proximodistal gradient along rat sciatic nerve.

Neurofilament (NF) proteins are distributed in a diminishing proximodistal gradient along rat sciatic nerve when compared with total noncollagen or other proteins in nerve. About a twofold decline of NF proteins can be detected by quantitating nerve proteins that have been separated by gel electrophoresis. A similar decrease of immunoreactivity to each NF subunit is seen in distal nerve segments when noncollagen nerve proteins are immunoblotted. Parallel decreases occur in all three NF proteins, thereby maintaining neurofilament subunit stoichiometry along the neuraxis. The same NF gradient can be detected when the NF contents in nerve branches to the gluteus and gastrocnemius muscles are compared with each other and with those in nerve segments taken from the same proximodistal levels of the parent sciatic nerve. The gradient of NF proteins increases during postnatal development and is readily detected by postnatal day 16. During the same period of development, the heavy NF subunit appears for the first time and is rapidly incorporated throughout the sciatic nerve. Hence, the NF gradient becomes manifest during the development and maturation of the adult form of the axonal cytoskeleton. The basis for the proximodistal gradient of NF proteins in peripheral nerve is presently unknown. The extent of the gradient cannot be accounted for on the basis of diminishing numbers of nerve fibers or increasing amounts of other nerve proteins, e.g., collagen, in distal nerve. An alternative interpretation is that the gradient reflects a low level of NF protein turnover during axonal transport.

Animals↗
PubMed1989

A large outbreak of Salmonella enteritidis phage type 4 associated with eggs from overseas.

In February 1989 the largest reported outbreak to date in the United Kingdom of Salmonella enteritidis phage type 4 (PT4) infection occurred following a wedding reception at a hotel. One hundred and seventy-three people met the case definition of illness of whom 118 had the organism isolated from their stools. A further 17 were found to be S. enteritidis PT4 positive, but were asymptomatic. Lightly-cooked, egg-based sauces were the epidemiologically proven vehicles of infection. Investigations showed this outbreak to be the first to implicate imported European eggs as the source of infection. An unusual feature of this outbreak was a reported incubation period of less than 3 h for some of the confirmed cases of salmonellosis.

Animals↗
PubMed1988

Omphalocele with pyloroduodenal obstruction by extrinsic hepatic compression: a case report.

The diagnosis of gastroduodenal obstruction by hepatic compression following omphalocele closure must be suspected in the presence of persistent nonbilious vomiting. We feel that computed tomography (CT) is the appropriate imaging method to define the liver abnormality. Nonsurgical management is the best approach with nutritional support maintained by total parenteral nutrition until physiological resolution of the obstruction occurs.

Duodenal Obstruction↗
PubMed1987

Studies of neurofilaments that accumulate in proximal axons of rats intoxicated with beta,beta'-iminodipropionitrile (IDPN).

The paradigm of IDPN neuropathy was produced in rats in order to examine the neurofilaments (NFs) that accumulate in the proximal motor and sensory axons of intoxicated animals, and to compare the aggregated NFs with control NFs and with the depleted populations of NFs in the distal portions of the same experimental nerves. NFs were probed biochemically and histochemically, using a large and well-characterized library of monoclonal antibodies that included antibodies that are monospecific for each of the rat NF protein subunits (NF-H, NF-M, and NF-L) as well as antibodies that recognized differential phosphorylated states of rat NF-H and NF-M. All antibodies tested showed enhanced immunostaining of enlarged axons and of large spheroids in the spinal cord and dorsal root ganglia of experimental animals. Biochemical analyses of IDPN-treated animals revealed enrichment of NF-H, NF-M, and NF-L in homogenates of dorsal root ganglia and of proximal motor and sensory nerve roots as well as depletion of the three subunits in distal nerve roots and in sciatic nerves. Immunoblot revealed a uniform enrichment of NF-H, NF-M, and NF-L in NF aggregates as well as the same admixture of phosphorylated and dephosphorylated epitopes of NF-H and NF-M in experimental and in control tissues. The global increase of immunoreactivity in axonal swellings to antibodies that react with phosphorylated, nonphosphorylated, and phosphorylation-independent NF epitopes suggests that IDPN induces an accumulation of NFs in proximal axons without necessarily altering the state of NF phosphorylation.

Animals↗
PubMed1987

The operative management of posterior urethral valves.

The surgical management of posterior urethral valves remains controversial. To examine the effects and results of operative treatment in boys with proven posterior urethral valves, a retrospective study was undertaken. The case records of 33 male children who presented with posterior urethral valves over a 10-year period were reviewed. Two patients died prior to definitive treatment and one died postoperatively. Following resuscitation and diagnostic procedures, the remaining patients had eradication of the posterior urethral valves by electrothermic fulguration. In 14 patients this was performed using the Innes-Williams diathermy hook under control of contrast enhanced radiography. In 16 patients the valves were fulgurated under direct cystoscopic visualization. All surviving patients had an uneventful postoperative recovery. However, of those undergoing cystoscopic fulguration, four developed symptomatic urethral strictures necessitating repeat cystoscopy and urethral dilatation. No cases developed strictures following the use of the diathermy hook. One patient from each treatment group developed dribbling. The Innes-Williams diathermy hook has been proven to be a safe, simple, and inexpensive technique. This has specific application in the neonate and small infant where cystoscopy poses technical problems because of anatomic size and where potentially traumatic urethral instrumentation should be avoided.

Child↗
PubMed1987

The relative merits of various methods of indirect measurement of intraabdominal pressure as a guide to closure of abdominal wall defects.

Visceral ischemia secondary to increased intraabdominal pressure (IAP) following closure of abdominal wall defects presents a serious postoperative problem. Currently, the method of closure and postoperative management are determined by clinical impressions rather than measurement of IAP. In this study various methods of indirectly measuring IAP were compared in 17 rabbits in which IAP was sequentially increased with an intraabdominal balloon. Vesical and inferior vena caval (IVC) pressures were found to have good statistical correlation with IAP. Other methods tested were gastric, rectal, superior vena caval, femoral and brachial artery, and rectus compartment pressures. All were found to be poor indicators of actual IAP. In nine of the rabbits, radiolabeled microspheres were used to assess cardiac output and visceral blood flow. Renal blood flow was very sensitive to increased IAP with dramatic impairment at IAP above 10 to 15 mmHg. Small intestinal flow was less sensitive and did not become significantly diminished until IAP exceeded 25 to 30 mmHg. Our studies suggest that vesical and IVC pressure monitoring should be used to evaluate IAP in the clinical setting. If IAP is in excess of 10 to 15 mmHg surgical intervention is indicated to prevent the development of renal ischemia.

Abdominal Muscles↗