Search PubMed⌕ Search

Biomedical subjects

R Scott

Publications and source records attributed to R Scott.

At least 217 records · Page 12Linked to original sources

Effect of enprostil on glucose and lipid metabolism in type 2 diabetes.

Enprostil, a dehydro-prostaglandin E2 analogue, has been tested as treatment for peptic ulcer. Its effect on blood glucose and lipid metabolism in Type 2 diabetes was assessed in a randomized, double-blind trial. Fifteen patients on sulphonylurea therapy received, in addition, enprostil 35 micrograms or placebo thrice daily for two weeks, with a 2-week wash-out before crossover. Data from 12 patients were analysed. After a 530 Cal test breakfast at the end of active treatment, plasma glucose rose from a fasting concentration similar to that after the last placebo dose (10.5 +/- 0.8 (+/- SE) and 10.6 +/- 1.1 mmol l-1 respectively) to 1, 2 and 3 h concentrations which were 1.5 to 2.1 mmol l-1 lower than on placebo (2 h concentration 14.6 +/- 0.9 vs 16.4 +/- 1.3 mmol l-1, p less than 0.05). Serum fructosamine concentrations at the end of active treatment and placebo were 3.66 +/- 0.22 and 3.78 +/- 0.24 respectively (p = 0.051). No changes in fasting or post-prandial insulin concentrations were observed. After 2 weeks of enprostil, fasting serum triglyceride (1.76 +/- 0.18 mmol l-1) and total cholesterol (6.27 +/- 0.29 mmol l-1) concentrations were lower than after placebo (2.14 +/- 0.25 and 7.35 +/- 0.46 mmol l-1, p = 0.031 and p = 0.002, respectively), the latter effect being primarily due to reduced LDL-cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Interferon alfa, infectious virus, and virus antigen secretion in respiratory syncytial virus infections of graded severity.

Interferon alfa was measured by an immunoradiometric assay in the nasopharyngeal secretions of a group of infants admitted to hospital with respiratory syncytial virus infection. Virus replication in the upper respiratory tract was assessed by infectivity assay and by an enzyme linked immunoadsorbent assay for the viral fusion protein on the same nasopharyngeal secretions. All infants were examined daily while in hospital and allocated a score based upon a subjective assessment of the severity of their illness. There was no significant correlation between interferon, virus, or fusion (F) protein secretion and severity of illness or age of infant. It is concluded that poor interferon alfa secretion does not underly the susceptibility of infants to severe infections with this virus.

Antigens, Viral↗

IgG and IgM antibodies to viral glycoproteins in respiratory syncytial virus infections of graded severity.

Serum antibodies to the fusion (F) and large glycoprotein (G) of respiratory syncytial virus in the serum of 57 infected infants were measured by enzyme linked immunosorbent assay (ELISA). Most serum samples taken at the time of admission to hospital contained antibodies to both glycoproteins, and overall there was no significant evidence of a selective deficiency of antibody to either viral antigen. Less than a quarter of the infants showed rising IgG antibody titres to either glycoprotein after infection, whereas over threequarters produced an IgM response. There was a significant correlation between IgG response to viral glycoproteins and the age of the infant. The correlation of age with the IgM response was less pronounced, and there was no correlation between serum IgG antibody derived transplancentally in the acute phase of infection and IgM response to either glycoprotein. Neither IgG or IgM responses correlated with a clinical assessment of the severity of infection in the infants. IgM responses, however, were weakly correlated with reduced secretion of infectious virus in the upper respiratory tract.

Antibodies, Viral↗

Some observations on the regeneration of smooth muscle in the repaired urinary bladder of the rabbit.

The regeneration of smooth muscle appears to take place within the fibrous tissue characteristically found when a biodegradable collagen/Vicryl prosthesis is used to repair full thickness defects in the rabbit urinary bladder. The question of whether the central smooth muscle was the result of myoblastic differentiation in the fibrous tissue or arose from healthy pre-existing detrusor muscle was resolved by serial sectioning and specific staining. Only in situ transmutation, or differentiation, explains the morphology, and the results therefore strongly suggest that this central smooth muscle regenerated from within the repair area.

Animals↗

The effect of foster feeding and bottle feeding expressed breast-milk on the susceptibility of guinea-pig infants to influenza virus.

Infant guinea-pigs born to mothers immunized against influenza virus by infection during pregnancy were reared from birth by non-immune foster mothers. As a control for the effects of fostering, a similar group were fostered to immune mothers. Fostering, regardless of the immune state of the foster-mother, increased the susceptibility of the infant to upper respiratory tract infection. Increased susceptibility was associated with ablation of the infants IgM and IgA antibody responses and reduced secretion of transplacentally acquired IgG antibody in nasal secretions. In the reciprocal experiment, infants of non-immune mothers fostered to immune mothers cleared virus more rapidly than their peers who were fed by their own mothers. This protective effect was associated with an enhanced nasal IgM and IgA antibody response. Infants of immune mothers separated from their mothers at birth and hand-reared on a cow's-milk-based formula feed suffered an increased susceptibility to the virus similar to that seen in fostered infants. Addition of a pool of expressed milk from a group of immune mothers, including their own, to the feed of hand-reared infants did not reduce their susceptibility. However, a further group of infants fed a non-cellular whey fraction of the same milk pool secreted significantly lower titres of virus. This increased protection was associated with elevated levels of IgG antibody secretion into nasal washes early in infection.

Animal Nutritional Physiological Phenomena↗

Isolation of a complementary DNA clone encoding a precursor to human eosinophil major basic protein.

A 14-kD protein was purified from human PMNs and its NH2-terminal sequence was determined. Comparison of a portion of the NH2-terminal sequence of this protein to the recently reported NH2-terminal sequence of eosinophil major basic protein (MBP) showed them to be identical. To aid further characterization of the structural and functional properties of this molecule, we isolated from an HL-60 cDNA library a single class of cDNA clones whose sequence matched exactly the NH2-terminal amino acid sequence of the 14-kD polypeptide. Northern analysis of HL-60 cells suggests that MBP is constitutively expressed in HL-60 cells and is highly transcribed from a single copy gene. The sequence of the full-length cDNA clones predicts that MBP is synthesized as a 23-kD precursor form (pro-MBP) which is subsequently cleaved to release the mature 14-kD MBP. The putative pro-MBP has a predicted pI of 6.0, but both the charged and the hydrophobic residues are asymmetrically distributed, creating a bipolar molecule. The NH2-terminal half has a predicted pI of 3.7 and is hydrophilic, while the COOH-terminal half (corresponding to mature MBP) has a predicted pI of 11.1 and is hydrophobic.

Base Sequence↗

The in-vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for potential use in urinary tract surgery. III. Adherence of bacteria to the material surface.

A Collagen/Vicryl (Polyglactin) composite membrane (developed for use in urinary tract surgery) has been incubated in cultures of radioactively labelled urinary tract pathogens vis Escherichia coli, Staphylococcus epidermidis, and Proteus mirabilis for up to 1 h. For comparison, collagen film, Vicryl mesh, and a number of absorbable and non-absorbable sutures were similarly tested. Following incubation, samples were also examined by scanning electron microscopy. Under the experimental conditions employed, only minimal adherence of the micro-organisms to the collagen coated Vicryl mesh, its two individual components, as well as Vicryl and nylon sutures was observed. Significantly greater numbers of bacteria, however, adhered to silk and Chromic Catgut. The results suggest that adherence of microorganisms to the prosthesis even in infected urine is unlikely to develop into a microcolony of bacteria. However, it should be emphasised that great care must be exercised when extrapolating from the in-vitro to the in-vivo situation.

Bacterial Adhesion↗

The in-vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for use in urinary tract surgery. II. Surface deposition of urinary salts.

Collagen coated vicryl mesh has been incubated with a series of urine collections from healthy and stone-forming patients. For comparison, collagen film, vicryl mesh, and a number of absorbable and non-absorbable sutures were similarly tested. Incubation in rabbit urine were also included in the study. Deposition of urinary salts, estimated qualitatively by electron microscopy, were observed on the collagen vicryl composite in approximately two thirds of the urines tested including rabbit urine. Those urines from patients with a high calcium excretion in particular caused urinary deposits on the material. Similar results were obtained with collagen film although the latter was not tested in rabbit urine. Considerably less deposits of urinary constituents were found with other absorbable materials such as vicryl mesh, vicryl sutures, and chromic catgut, whereas a higher proportion of concretions were found with the non-absorbable sutures. The results indicate that urinary salt deposition may be a problem associated with collagen based composite materials after prolonged exposure to urine. It must, however, be emphasised that great care should be exercised when extrapolating any results obtained in-vitro to the in-vivo situation.

Animals↗

Hyperthermia in combination with definitive radiation therapy: results of a Phase I/II RTOG Study.

Between August 1981 and April 1986, 133 patients with superficial malignant tumors not previously treated with radiotherapy were entered on a Phase I/II RTOG study evaluating hyperthermia plus definitive radiotherapy. Eligible patients included those with superficial epithelial or mesenchymal tumors less than 4 cm in depth. Protocol radiotherapy specified a tumor dose of 60 Gy delivered in 1.8-2.0 Gy fractions 5 times/week with a boost of 5-10 Gy through reduced portals to residual tumor. Protocol hyperthermia, delivered twice weekly, was to start within 15 minutes following irradiation and to consist of 60 minutes of heat to a tumor temperature of 43 degrees C. Sixteen patients were excluded. Of the 117 eligible patients, the treated lesions had site/histologies which were 35% head & neck/squamous, 46% breast/adenocarcinoma, and 19% other site/histologies. Lesions were 3 cm or larger for 77% of patients. Of the 41 patients with head & neck/squamous lesions, skin or subcutaneous necrosis occurred within 6 months for 2% of the patients; 12% experienced thermal blisters. Fourteen patients were followed for 6 months or more following start of treatment; none of these experienced late toxicities more severe than telangiectasis. Complete responses were observed in 51% of these patients. Of the 54 patients with breast/adenocarcinoma lesions, skin or subcutaneous necrosis occurred within 6 months for 13% of the patients; 17% experienced thermal blisters. Thirty-seven patients were followed for 6 months or more following start of treatment; complications observed during this period included 13% with ulceration and one case of skin necrosis. Complete responses were observed in 85% of these patients. Local control was maintained at nearly this level for at least 2 years. Logistic regression analyses showed site/histology, greatest tumor diameter and average tumor temperature to be significantly related to response. Based on these promising findings, the RTOG has instituted a randomized Phase III study evaluating radiation therapy with or without hyperthermia in this patient population.

Adenocarcinoma↗

Transdermal estrogen replacement in ovarian failure for ovum donation.

This study examined the efficacy of transdermal estradiol (TE2) replacement versus oral estradiol (OE2) through evaluation of peripheral steroid levels, endometrial morphology, and clinical outcome in six patients with ovarian failure. Patients were begun on sequential E2 and progesterone replacement with transdermal E2 patches. Endometrial biopsies were done on day 21 of the first replacement cycle and day 26 of the second cycle. Controls were 28 cycles on a regular 28-day micronized OE2 protocol. No significant difference was found between E2 levels throughout the cycle of the two respective stimulation protocols, except for days 12 to 14, when the OE2 protocol produced significantly lower E2 than did the TE2 protocol (P less than 0.01). A positive, highly significant correlation was found between estrone (E1) and E2 values in the OE2 group (r = 0.92) (P less than 0.003). During OE2 administration, E1 was significantly higher than E2 (P less than 0.01). E1 was not found to be higher than E2 in the TE2 group, resulting in a significant difference in the E2/E1 ratio of 1.59 +/- 1.6 for TE2 compared with 0.13 +/- .04 for OE2 (P less than 0.05). Early biopsies in patients on TE2 revealed glandular components that were dated as day 18.2 +/- 1.7, while the stroma was dated as day 21.8 +/- 0.8, a statistically significant disparity (P less than 0.01). In patients on OE2, the same significant 3-day glandular/stromal disparity was observed (P less than 0.05). Morphologic evaluation of late biopsy specimens revealed day 25.0 +/- 0.8 and 24.5 +/- 1.5 for TE2 and OE2 groups, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗

Educational level differences on the Mini-Mental State: the role of test bias.

Less educated elderly people are commonly found to perform more poorly on the Mini-Mental State Examination (MMSE). This educational level difference has been attributed by some research workers to test bias. To assess whether the MMSE is biased against the poorly educated, its validity was assessed separately in the more- and less-educated members of a community sample. No evidence was found to indicate that the test is a biased measure of cognitive impairment.

Aged↗

Spontaneous and pharmacologically induced remissions in patients with premature ovarian failure.

To determine the fertility potential of patients with apparent ovarian failure, a retrospective analysis of 86 ovarian failure patients in the Norfolk oocyte donation program was performed. None of the 23 patients with primary ovarian failure ovulated. Seven of 63 (11.1%) with secondary ovarian failure did ovulate, and three of 63 (4.8%) conceived and delivered normal, healthy infants. Of patients whose etiology for ovarian failure was partial ovarian resection or chemotherapy, the ovulation rate and pregnancy rate were 30.8 and 15.4%, respectively, compared with 5.0 and 1.7%, respectively, for the other patients with secondary ovarian failure. Serum estradiol and FSH obtained during hormone replacement were not predictive of the resumption of normal reproductive functions. Therefore, it is recommended that patients with secondary ovarian failure, especially in the better-prognosis group, be treated with a trial of estradiol replacement and have close monitoring for ovulation before oocyte donation.

Adult↗

The purification of four respiratory syncytial virus proteins and their evaluation as protective agents against experimental infection in BALB/c mice.

The fusion (F) glycoprotein, large glyco- (G) protein, phospho- (P) protein and 22K protein of respiratory syncytial (RS) virus A2 strain were purified by a combination of immunoaffinity adsorption and preparative SDS-PAGE. All four proteins elicited serum antibody in mice after repeated inoculation in adjuvant, although the magnitude of the response as measured by ELISA varied from mouse to mouse. The F protein generated neutralizing antibodies in only 50% of the mice determined to be seropositive by ELISA. The G protein also induced neutralizing antibodies but in this instance neutralization tests and ELISA titres were more closely correlated. No neutralizing activity was detected in mice immunized with the P or 22K proteins although all produced antibody detectable by ELISA. Mice immunized with either the F or the G protein were found to be protected against subsequent RS virus challenge, whether they had developed neutralizing antibody or not. Mice inoculated with the P or 22K proteins were not protected.

Animals↗

The evolution of a biodegradable membrane for use in urological surgery. A summary of 109 in vivo experiments.

The evolution of a collagen/vicryl composite membrane designed as a prosthetic material for use in urinary tract surgery is described. The early experiments in which collagen film alone was used to repair experimental ureterotomies are reviewed together with our first experiments with the collagen/vicryl prosthesis in the repair of partial nephrectomies and of full thickness defects created in the urinary bladder of experimental rabbits. These early results led to the preparation of a composite using a more highly purified collagen and employing a method of sterilisation (gamma irradiation) which would be acceptable for regular use in medical products. The results of a further series of partial nephrectomy and full thickness bladder repairs show that irradiation does not compromise the efficacy of the collagen/vicryl composite in vivo.

Animals↗

Clinico-pathologic studies in dementia: nondemented subjects with pathologically confirmed Alzheimer's disease.

We compared neuropsychological findings in 28 longitudinally evaluated elderly subjects with their postmortem neuropathology, including senile plaque and neurofibrillary tangle counts from standardized sections. Nine of the subjects were not demented when evaluated just prior to their death. Numerous cortical senile plaques and other changes of Alzheimer's disease (AD) occurred in six of nine nondemented old-old subjects. Five of these six subjects had shown decline on yearly neuropsychological tests but their cognitive impairment was too mild to meet clinical criteria for dementia. Whereas cortical senile plaque count did not distinguish well between demented and nondemented subjects, every subject with numerous cortical neurofibrillary tangles was demented. The nondemented subjects with Alzheimer pathology may have had "preclinical" AD, or numerous cortical plaques may occur in some elderly subjects who would never develop clinical dementia.

Aged↗

The susceptibility of breast-fed and cow's milk formula-fed infant guinea pigs to upper respiratory tract infection with influenza virus.

Breast-fed infant guinea pigs from immune mothers were partially protected against infection with influenza virus when compared to those from nonimmune mothers. Virus titres in nasal washes at 24 h post-infection were reduced and virus clearance from the upper respiratory tract accelerated. When infants of immune mothers were deprived of colostrum and hand-reared on a formula-feed their ability to reduce virus yields at 24 h post-infection was lost. Infants partially breast-fed and partially formula-fed gave total virus yields similar to their fully breast-fed peers. Infants of immune mothers possessed high titres of serum IgG antibody to the virus prior to infection. Post-infection, IgG antibodies appeared on the mucosal surface of breast-fed seropositive infants earlier than for seronegative infants of nonimmune mothers but IgM and IgA responses of seropositive infants were less vigorous than those of seronegative infants. There was little evidence that antibody present in a mother's milk was transmitted to the nasal mucosa of her offspring. Fully and partly formula-fed seropositive infants showed enhanced transudation of serum IgG antibody on to the mucosal surface and this effect was most marked in the partly formula-fed group which showed greater protection. In both formula-fed groups serum and nasal IgM and IgA responses were completely suppressed.

Animals↗