Search PubMed⌕ Search

Biomedical subjects

P Wilson

Publications and source records attributed to P Wilson.

At least 181 records · Page 10Linked to original sources

The dermatomes of the pectoral and pelvic fin of the long-tail stingray Himantura fai.

Recorded action potentials in whole spinal nerves during mechanical stimulation of the skin of Himantura fai revealed that sequential nerves innervated sequential overlapping strips of the pectoral and pelvic fin skin. As found in previous studies, in which the dermatomes of the skate Raja clavata were measured behaviourally, approximately one-third of the rostral and caudal regions of each dermatome overlapped with the adjacent dermatomes. Consistent with dermatomal maps from non-mammalian vertebrates, but unlike the dermatomal maps obtained in mammals, there appears to be little difference in dermatome size when measured behaviourally or electrophysiologically. We suggest that neural mechanisms of the spinal cord, which appear to contribute to the discrepancy between behaviourally and electrophysiologically mapped dermatomes in mammals, are of negligible influence in stingrays.

Afferent Pathways↗

The effect of eight V2 vasopressin receptor mutations on stimulation of adenylyl cyclase and binding to vasopressin.

We previously identified six V2 vasopressin receptor mutations in five unrelated nephrogenic diabetes insipidus (NDI) families. In order to elucidate the effect of these mutations on the function of the V2 vasopressin receptor, we introduced these six and two additional, naturally occurring mutations into the V2 vasopressin receptor gene by in vitro mutagenesis. Five of the mutants (two frameshift, one nonsense, and two missense) failed to stimulate adenylyl cyclase due to their inability to bind vasopressin under the experimental conditions. In contrast, ligand binding and cAMP accumulation were normal for two other mutations, a A61V missense mutation and an in-frame deletion of four amino acids (Arg-247 to Gly-250), suggesting that they are not the cause of NDI in these families. The deletion mutation was found in a family in conjunction with a second mutation, R181C, which yielded a much reduced ligand-binding capacity. The KD of R181C was at least 26 times higher than that of the wild type. Further characterization by an immunofluorescent assay showed that the R181C mutant receptor is expressed and distributed on the cell surface in a manner similar to that of the wild type. This finding indicates that the inability of this mutant to stimulate adenylyl cyclase is caused by the reduced capacity for vasopressin binding and that the R181C mutation is responsible for NDI in this family.

Adenylyl Cyclases↗

Female sterilisation: National Women's Hospital 1988-9.

AIM: To determine the failure rate of all female sterilisation procedures performed at National Women's Hospital in order to identify ways of improving the service. METHODS: A review was made of all sterilisation procedures performed at National Women's Hospital in 1988 and 1989. All patient notes and theatre records were examined. A consumer questionnaire was mailed to all patients monthly for 3 months. If there was no response efforts were made to contact these women via their last known general practitioner. Epsom Day Hospital where 95% of all terminations of pregnancy in Auckland are performed also examined their records. RESULTS: 1094 procedures were performed at National Women's Hospital in Auckland during 1988 and 1989. Failures were classified into two groups: those pregnant at the time of surgical procedure (administrative failures) and those pregnant after the procedure (surgical failure). There were 15 surgical failures (1.4%). Laparoscopy using Filshie clips was the most common method used and had a 1.2% surgical failure rate. Registrars had a 1.3% failure rate, consultants 1.9% and when both a consultant and registrar performed the procedure a failure rate of 0.7% was recorded. Eighty-six percent (6/7) of women who had a subsequent laparotomy after a failed sterilisation were found to have surgical misapplication of the occlusive device. There were 7 (0.6%) women who were pregnant at the time of the procedure. There were no patient or procedure-related factors which were associated with failures. CONCLUSION: Sterilisation is associated with a significant failure rate. Contraception counselling at the time of booking for the procedure needs to be improved. Preoperative pregnancy testing should be introduced to avoid sterilisation procedures in early pregnancy. Surgical misapplication of devices was a common cause of failure, not recanalisation as found elsewhere. From this review it would appear that the involvement of two surgeons lowers the failure rate.

Female↗

The development of community orientated recommendations for diabetes care in south Auckland. South Auckland Community Diabetes Planning Group.

Growing numbers and costs associated with diabetes and its tissue damage are of increasing concern. We describe the development of community orientated recommendations aimed at primary and secondary prevention of diabetes in an area with a high proportion of Maori and Pacific Islands people. Preliminary results from structured face-to-face interviews with patients (n = 555), general practitioners (n = 163) and other health professionals were discussed by a core group of elected or selected community and health professional representatives. Twelve meetings and one full day workshop were held over a 7 month period. Formal and informal consultation occurred among community and health groups between meetings. The 68 recommendations included the need to: empower communities and diabetic patients; improve coordination and standardisation of care and the importance of the general practitioner in this process; improve access to care by removing transport, cultural and language barriers to care; subsidize preventative treatment costs; improve foot and eye services; improve monitoring of those with past diabetes in pregnancy or impaired glucose tolerance; improve detection of diabetes by increased high risk screening linked to ongoing diabetes care programmes. Implementation requires quality information systems and a cooperative partnership approach between hospital, general practitioner and the community, particularly local Maori and Pacific Islands communities.

Community Health Services↗

Expression and distribution of functional integrins in rat CNS glia.

In previous studies, we have reported on the expression of beta 1 integrins in type 1 astrocytes and their function in cell-substratum attachment (Tawil et al., J Cell Biol 120:261-271, 1993). Here we extend those findings by providing evidence that type 1 astrocytes express integrins of the beta 3 and possibly beta 4 subclasses and that the former (alpha v beta 3) functions in attachment by recognizing the peptide, Arg-Gly-Asp, in vitronectin. In addition, we have examined immunocytochemically the expression of beta 1 integrins on type 2 astrocytes and oligodendrocytes. The pattern of expression of integrins on these two cell types is distinct from type 1 astrocytes; most notably type 1 astrocytes but not oligodendrocytes or type 2 astrocytes express alpha 1 beta 1 heterodimers. Since type 2 astrocytes and oligodendrocytes originate from a common precursor (O-2A), the alpha 1 beta 1 heterodimer may be a functional marker which distinguishes O-2A-derived cells from those of the type 1 astrocyte lineage.

Amino Acid Sequence↗

Methadone maintenance in general practice: patients, workload, and outcomes.

OBJECTIVE: To assess recruitment to and work-load associated with methadone maintenance clinics in general practice; to investigate the characteristics of patients and outcomes associated with treatment. DESIGN: Study of case notes. SETTING: Methadone maintenance clinics run jointly by general practitioners and drug counsellors in two practices in Glasgow. PARTICIPANTS: 46 injecting drug users receiving methadone maintenance during an 18 month period, 31 of whom were recruited to clinic based methadone maintenance treatment and 15 of whom were already receiving methadone maintenance treatment from the general practitioners. Mean (SD) age of patients entering treatment was 29.6 (5.5) years; 29 were male. They had been injecting opiates for a mean 9.9 (5.1) years, and most had a concurrent history of benzodiazepine misuse. Average reported daily intake of heroin was approximately 0.75 g. Participants in treatment had high levels of preexisting morbidity, and most stated that they committed crime daily. RESULTS: 2232 patient weeks of treatment were studied. Mean duration of treatment during the study period was 50.7 (21.1) weeks and retention in treatment at 26 weeks was 83%. No evidence of illicit opiate use was obtained at an average of 78% of patients' consultations where methadone had been prescribed in the previous week; for opiate injection the corresponding figure was 86%. CONCLUSIONS: Providing methadone maintenance in general practice is feasible. Although costs are considerable, the reduction in drug use, especially of intravenous opiates, is encouraging. Attending clinics also allows this population, in which morbidity is considerable, to receive other health care.

Adult↗

Evaluation of school children at high risk for fragile X syndrome utilizing buccal cell FMR-1 testing.

We describe a pilot project utilizing saliva to identify the FMR-1 mutation in high-risk special education students from four public school districts in Colorado. The program included presentations to special education teachers regarding fragile X syndrome, parental consent for testing, completion of a behavior checklist by the teachers, identification of special education students at high risk for fragile X syndrome, subsequent brief examination of face and hands, collection of a saliva sample by either Gatorade swish or brushing of the inside of the cheek, and analysis for the FMR-1 mutation by PCR. Equivocal samples were studied by direct DNA testing using Southern blot analysis, and abnormal results were confirmed by a blood analysis for the FMR-1 mutation. Mutant individuals received genetic counseling and medical and educational assessments to optimize treatment and intervention. This pilot project was met with enthusiasm by the schools. Of the first 439 students evaluated, 68% were male with an average age of 7.75 years; 13% were mentally retarded or autistic. Most students referred for the evaluation were learning disabled (51%) and/or had an Attention Deficit Hyperactivity Disorder (ADHD) (35%). The overall prevalence of the FMR-1 mutation was 5 of 439 or 1.1%. This relatively low yield is probably due to the high number of non-retarded but learning disabled students tested. Of the mentally retarded patients tested, 3.5% were positive for the FMR-1 mutation; however, of the non-retarded or learning disabled patients, only 0.79% were FMR-1 positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Sciatic axotomy compromises axonal transport of transganglionic tracer BSI-B4 from the soma to the central terminals of C fibre afferents.

The C afferent specific lectin BSI-B4 was used to examine the effects of sciatic axotomy on axonal transport by the C afferent subpopulation. From about 4 days after sciatic nerve lesion, BSI-B4 injected into the peripheral nerve is transported only as far as the neuronal cell bodies in the dorsal root ganglion. The previous demonstrations of A beta afferent terminal sprouting into lamina II, and the atrophy of lamina II terminals, in response to sciatic lesions may be related to the inability of C afferents to maintain transganglionic transport.

Animals↗

Reference data for bone mass, calciotropic hormones, and biochemical markers of bone remodeling in older (55-75) postmenopausal white and black women.

From a random sample of our institution's health maintenance organization (HMO), we recruited 250 white women and 112 black women, aged 55-75, all of whom were 10 or more years postmenospause with minimal estrogen exposure and free of osteoporosis, other metabolic bone disease, and medical, surgical, or therapeutic situations that may influence bone loss. Bone mass was measured in the radius, spine, and femur by DXA and in L1 by QCT. Serum samples were analyzed for parathyroid hormone, calcidiol, calcitriol, osteocalcin, and bone alkaline phosphatase and urine samples analyzed for creatinine, calcium, and hydroxyproline. Mean Z score, based on published reference data for forearm and femoral neck BMD in the white women, was not significantly different from zero, but mean Z score at the lumbar spine was 0.6 (p < 0.001), 17.2% of the individual values being > 2.0. In normal white women (BMI < 27.3, n = 143), Z score was still > 2.0 in 10.3%, suggesting that the upper bound of the published reference interval may be too low. After adjustment for body mass index, BMD was greater in the forearm (9.8%), spine (8.7%), and femoral neck (14.7%) in black women (p < 0.001 at all sites). At L1, adjusted BMC in the black women was 37.4% greater than in the white women (p < 0.001). Serum calcidiol was significantly lower and serum PTH and calcitriol significantly higher in the black women. Despite this, biochemical markers of bone resorption and formation were significantly lower in the black women. We conclude that skeletally healthy older black women have a greater bone mass and lower rates of bone remodeling than a comparable group of white women. These data can serve as reference intervals for the variables measured.

Aged↗

Transganglionic labelling of primary sensory afferents in the rat lumbar spinal cord: comparison between wheatgerm agglutinin and the I-B4 isolectin from Bandeiraea simplicifolia.

We recently reported that the I-B4 isolectin from Bandeiraea simplicifolia could be used as a transganglionic neuronal tracer which appears to be selective for unmyelinated cutaneous afferents (C fibres) and their terminals in the superficial dorsal horn. As terminals in the superficial dorsal horn are also labelled by wheatgerm agglutinin, we sought to compare these two neuronal tracers. Three days after the injection of 1% wheatgerm agglutinin-HRP or 1% BSI-B4-HRP into the sciatic nerve of adult rats the lumbar spinal cord was processed for HRP reactivity. The majority of labelled structures was found in the superficial dorsal horn, with fewer labelled structures seen in the overlying white matter (including Lissauer's tract). In wheatgerm agglutinin-HRP experiments most labelled structures were synaptic terminals (63%) and unmyelinated axons (32%). About 3% of wheatgerm agglutinin-HRP-labelled structures were fine myelinated fibres (which were found only in lamina I and outer lamina II) and about 2% of label was located in neuronal somata. In contrast, label from BSI-B4-HRP experiments was found only in synaptic terminals (37%) and unmyelinated axons (63%). Previous studies have shown that small diameter dorsal root ganglion neurons and their terminals in the superficial dorsal horn express a range of structurally related carbohydrates that contain binding sites for BSI-B4 or wheatgerm agglutinin or both. Comparison of the labelling patterns produced by the two transganglionic tracers in the present study suggests that unmyelinated sciatic afferents express wheatgerm agglutinin and BSI-B4 binding sites, but some thin myelinated afferents, and a distinct form of synaptic terminal in lamina I/II outer, express the wheatgerm agglutinin binding site and not the BSI-B4 binding site.

Afferent Pathways↗

Gastroesophageal reflux disease is associated with enteric hormone abnormalities.

Basal and postprandial levels of the foregut hormones gastrin, cholecystokinin (CCK), motilin, and pancreatic polypeptide, and the distal gut hormones neurotensin and peptide YY were measured in 20 patients with gastroesophageal reflux disease (GERD). GERD was defined by abnormal esophageal exposure to pH less than 4. Ten GERD patients had decreased lower esophageal sphincter (LES) pressure (mean: 4.5 mm Hg, range: 0.8 to 6.8 mm Hg), and 10 patients had normal LES pressures (mean: 14.1 mm Hg, range: 9.7 to 22.4 mm Hg). Eight age-matched healthy subjects were also studied. Basal levels of peptide YY were moderately decreased in GERD patients compared with controls irrespective of LES pressure. In patients with abnormal LES pressure, basal levels of motilin and the postprandial response of CCK were significantly decreased compared with controls; and basal levels of neurotensin and the postprandial response of gastrin were significantly increased compared with controls. Pancreatic polypeptide levels were similar in all groups. These gut hormone changes, which are more marked in patients with poor LES pressure, may reflect primary or secondary abnormalities in GERD.

Esophagogastric Junction↗

Association between the histological diagnosis of tuberculosis and microbiological findings.

The aim of this study was to determine the association between the histological diagnosis of tuberculosis and the microbiological findings and to indicate how these results affect treatment. Histopathology and microbiology records were examined retrospectively. 89 cases were identified between 1984 and 1988. 67% were diagnosed as tuberculosis (TB) by both methods, 97% were diagnosed as TB or 'compatible with TB' by histology. For 7% of these the final diagnosis was found to be other than TB. 48% of patients diagnosed as TB on the basis of histology alone were treated for TB. 70% were diagnosed as TB by microbiology and treated. When matched and appropriate specimens were sent to both departments there was a high level of agreement between histopathologists and microbiologists. There was a problem with inappropriate specimens sent to microbiology.

Adolescent↗

Altered antroduodenal motility after cholecystectomy.

BACKGROUND: Persistent nonspecific symptoms such as epigastric pain, bloating, nausea, and bilious vomiting are common following cholecystectomy. The etiology of these symptoms is unknown, but abnormal antroduodenal motility associated with duodenogastric reflux (DGR) is a possible cause. PATIENTS AND METHODS: Sixteen postcholecystectomy patients and 19 healthy volunteers ("normals") were studied. Ten of the patients were asymptomatic and 6 were symptomatic. The study consisted of a 4-hour 99mTc-DISIDA (diisopropyl imidodiacetic acid) infusion and gastric aspiration, 24-hour intragastric pH monitoring, and 24-hour ambulatory antroduodenal manometry. RESULTS: The postcholecystectomy patients showed increased DGR of the infused 99mTc-DISIDA. The data are given as coulter counts x 10(6)/min. The increase was more marked in symptomatic postcholecystectomy patients (2.54 +/- 0.15) compared to asymptomatic patients (1.21 +/- 0.46) or normals (0.26 +/- 0.15). Postcholecystectomy patients had increased percentage of time with intragastric pH > 3. In the supine period in particular, the pH was > 3 in symptomatic patients 25.4% +/- 7.7% of the time versus 8.1% +/- 4.3% for asymptomatic patients (P < 0.01). The antral phase III frequency after cholecystectomy was 2.5 +/- 0.09 cycles/min compared to 3.2 +/- 0.08 cycles/min in normals (P < 0.0001). Furthermore, propagation of the phase III front in the duodenum was significantly slowed to 0.14 +/- 0.02 cm/s after cholecystectomy compared to 0.27 +/- 0.02 cm/s in normals (P < 0.001). The duration of phase III in the proximal duodenum after cholecystectomy was also decreased to 4.3 +/- 0.27 min compared to 5.9 +/- 0.35 min in normals (P < 0.005). CONCLUSIONS: Fasting antroduodenal motility is altered after cholecystectomy. The abnormality is associated with increased DGR, which is more marked in symptomatic patients.

Adult↗

Partners of problem drinkers: moving into the 1990s.

The literature on partners of problem drinkers is reviewed. Originally research and treatment viewed partners of problem drinkers from a pathological perspective. This paper suggests an alternative stress and coping perspective as less stigmatizing and more realistic in terms of the experiences of these individuals.

Journal Article↗

Protein-specific cervical antibody responses to primary genital herpes simplex virus type 2 infections.

Antibodies to herpes simplex virus (HSV) have been demonstrated in cervicovaginal secretions but have not been analyzed for their viral protein targets, prevalence, isotype, or kinetics of development. A method was devised to collect cervical secretions from women with primary genital HSV-2. By Western blot, cervical IgG and IgA responses to HSV-2 proteins VP5, gB, and gD were detected in most patients within 2 weeks of onset and to gC/gE within 3 weeks. Cervical IgM and IgG responses to gG, VP16, and ICP35 developed later and were more variable. Cervical IgM to most proteins appeared within 6-10 days. Cervical IgA and IgG persisted for weeks, but cervical IgM waned. Western blot profiles of serum IgG and cervical IgG to individual HSV-2 proteins were similar; those of serum IgA and cervical IgA differed. These findings suggest a universal, complex immune response to HSV-2 infection in the female genital tract.

Adult↗