Search PubMed⌕ Search

Biomedical subjects

P Matthews

Publications and source records attributed to P Matthews.

At least 55 records · Page 3Linked to original sources
PubMed1996

Recovery of muscle strength following arthroscopic meniscectomy.

The purpose of this study was to investigate the time course of spontaneous recovery (no supervised training) of muscle torques in the first 3 months postarthroscopic partial meniscectomy. This information will then be used to plan a clinical trial investigating the effects of rehabilitation following arthroscopic meniscectomy. Knee extensor and flexor strength was evaluated at four different velocities (60, 120, 180, and 240 degrees/sec) preoperatively and every 2 weeks from weeks 2-12 postsurgery. Eight subjects were evaluated on a Cybex II+ and 14 subjects were evaluated on a Cybex II isokinetic device. A repeated measures analysis of variance was used to determine possible side (involved and uninvolved), speed (60, 120, 180, and 240 degrees/sec), or time (preoperative, 2, 4, 6, 8, 10, and 12 weeks postoperatively) effects as well as possible interactions between these factors. Prior to partial meniscectomy, the involved quadriceps was significantly weaker than the uninvolved quadriceps only at 60 degrees/sec (15%). A further decrease in torque was noted at 2 (25-40% deficit depending on the velocity) and 4 weeks postsurgery at all speeds (17-25%). The quadriceps recovered to preoperative values by 4-6 weeks postsurgery and stabilized at this level until the end of the study, at which time the quadriceps remained weaker than the contralateral side at 60 degrees/sec (14%) and 120 degrees/sec (12%). Prior to surgery, the involved hamstrings were comparable with the uninvolved hamstrings. Although significant differences between sides were found at week 2 postsurgery at 60 (23%) and 120 degrees/sec (17%), the hamstrings were fully recovered by 4 weeks postoperatively. In conclusion, although the quadriceps may recover to preoperative levels by 4-6 weeks following partial meniscectomy, further recovery does not appear to be possible without training as the quadriceps remains weaker than the contralateral side up to 12 weeks postsurgery.

Adult↗
PubMed1996

Use of immunocytochemistry in the diagnosis of metastatic carcinoma.

Metastasis of unknown primary site is a common clinical problem. Immunohistochemistry has been shown to be a useful tool in the identification of the primary site. The availability of new antibodies specific for a wide range of antigens and working on routinely fixed, paraffin-imbedded material will ensure that this technique will continue to offer useful information in the search for an elusive primary tumour.

Diagnosis, Differential↗
PubMed1996

Using data to measure outcomes.

The health care marketplace is beginning to demand that providers develop and provide outcomes data. But implementing a process of collecting outcomes data can be very labor intensive. Planning must include defining outcomes, understanding how outcomes are used in analysis and decision-making activities, identifying data sources, and identifying the users.

Cost-Benefit Analysis↗
PubMed1996

Small bowel strangulation and infarction: an unusual complication of Meckel's diverticulum.

We report an unusual case of small bowel infarction as a result of strangulation by a long Meckel's Diverticulum (MD). In any patient with a MD there is approximately a 4% risk of developing complications. These include bleeding, intussusception, obstruction due to a mesodiverticular band, volvulus and herniation. We present a case in which strangulation was due to encirclement of the small bowel by a long MD.

Adolescent↗
PubMed1992

Prenatal testicular torsion: principles of management.

To assess our experience with in utero testicular torsion, we retrospectively studied all newborns presenting in the newborn nursery with a diagnosis of neonatal testicular torsion. A total of 25 consecutive cases of torsion of the spermatic cord in 23 patients was identified and explored on an emergency basis. To our knowledge this represents the largest single institution series and 40% of all of the confirmed cases reported in the literature. No viable testicles were found. We strongly believe that torsion of the testis presenting at birth represents an irreversible intrauterine event best treated in an early elective setting. We suggest an inguinal approach with contralateral orchiopexy in all patients who present with signs and symptoms of prenatal (in utero) testicular torsion.

Female↗
PubMed1991

Correlative multidisciplinary approach to the study of mitochondrial encephalomyopathies.

Mitochondrial encephalomyopathies can be caused by defects in the mitochondrial respiratory complexes. The clinical phenotypes are quite protean but in many instances a characteristic or suggestive clinical presentation permits a tentative bedside diagnosis. The diagnosis can be verified by laboratory investigations. The major laboratory hallmarks of mitochondrial encephalomyopathies include: ragged red fibers on muscle biopsy, a specific defect or deficiency in a mitochondrial respiratory enzyme complex, mtDNA abnormalities, reduced anaerobic threshold by bicycle ergometry, impaired cellular energy state by MRS and characteristic brain imaging abnormalities. Monitoring of some of these parameters along with the clinical phenotype will aid in the evaluation of therapeutic trials.

Brain Diseases↗
PubMed1990

Insertional inactivation of the mec gene in a transposon mutant of a methicillin-resistant clinical isolate of Staphylococcus aureus.

All clinical strains of methicillin-resistant Staphylococcus aureus (MRSA) examined so far contain the mec gene and its product, the penicillin-binding protein (PBP) 2A. Yet the same strains show tremendous variation in the phenotypic expression of antibiotic resistance (MIC), which is under the control of a set of additional, auxiliary genes. Thus, the quantitative contribution of the mec gene to the resistance phenotype of MRSA is not known, and no mutants with the lesion located within the mec gene have been described. We subjected a highly resistant MRSA strain to transposon mutagenesis with the erythromycin resistance transposon Tn551, and a mutant expressing greatly decreased methicillin resistance (RUSA4) was selected to characterize the transposon insertion site. The results indicate that the Tn551 insertion site in mutant RUSA4 is between base pairs 1000 and 1400 of the sequence encoding PBP 2A. Thus, the uniform and greater than 200-fold drop in the methicillin MIC (4 micrograms/ml) for this mutant relative to that for the parent strain (MIC greater than or equal to 800 micrograms/ml) must be related to the inactivation of the PBP 2A gene. The results provide the first unequivocal evidence for the importance of PBP 2A as a quantitative contributor to the MIC for MRSA.

Blotting, Southern↗
PubMed1989

Inspired oxygen concentration during general anaesthesia for caesarean section.

The effects on maternal oxygen saturation, foetal wellbeing and umbilical blood gases were compared when parturients received either 30 or 50% oxygen prior to delivery by Caesarean section under general anaesthesia. Maternal arterial oxygen saturation was significantly increased in the group receiving 50% oxygen. There was no difference between the two groups in terms of Apgar score minus colour, time to sustained respiration or umbilical cord blood gas estimations. The use of 30% inspired oxygen during uncomplicated Caesarean section is advocated.

Adult↗
PubMed1984

Thyroid hormone metabolism and the source of plasma triiodothyronine in 2-week-old rats: effects of thyroid status.

Earlier studies have shown larger increments in serum T3 in 2-week-old congenitally hypothyroid rats than in euthyroid controls after injections of small doses of T4. Since hepatic and renal 5'-deiodination of T4 to T3 in vitro (5' D-I) is reduced during the neonatal period and in hypothyroidism, those results suggest that there may be major changes in the distribution and metabolism of T3 or that an alternative enzymatic pathway is the predominant source of extrathyroidally produced T3 in these rats. The alternative pathway, 5' D-II, is a relatively minor source of serum T3 in adult euthyroid rats, but the contribution of this pathway to the extrathyroid T3 pool during the neonatal period and in hypothyroxinemia is not known. Consequently, we studied [125I]T4 and [131I]T3 kinetics and fractional T4 to T3 conversion in 2-week-old euthyroid and hypothyroid rats and then explored the source of circulating T3 by manipulating 5' D-I activity with propylthiouracil and that of 5' D-II with thyroid hormone. The plasma clearance rate of T4 was increased in hypothyroid rats, a difference entirely accounted for by the faster fractional rate of irreversible removal in the hypothyroid pups. Plasma clearance rate of T3 was reduced in hypothyroid rats owing to the reduced volume of distribution of T3. Fractional T4 to T3 conversion was 2- to 3-fold higher in euthyroid or hypothyroid neonates than in adult rats. In euthyroid rats the serum concentration of T4 was 36 +/- 1 (SEM) ng/ml and that of T3 0.61 +/- 0.03 ng/ml, and the production rates were 432 and 159 ng day-1 30 g-1 BW for T4 and T3, respectively. About 80% of the T3 in euthyroid neonates was produced extrathyroidally . These findings are inconsistent with hepatic and renal 5' D-I being the main source of serum T3 in 2-week-old rats. In fact, liver and kidney 5' D-I activities were 40% and 65% of the corresponding adult values in euthyroid neonates, and in hypothyroid pups were further reduced to 15% and 17%. In contrast, 5' D-II, previously reported to be high in central nervous tissue and pituitary, was 7-10-fold higher in brown adipose tissue (BAT) of hypothyroid pups than in that of euthyroid ones.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗