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Biomedical subjects

W A Reid

Publications and source records attributed to W A Reid.

At least 37 records · Page 2Linked to original sources
PubMed1989

Immunolocalisation of aspartic proteinases in the developing human stomach.

The distribution and time of appearance in the developing human stomach of the 4 aspartic proteinases, pepsinogen, progastricsin, slow-moving protease and cathepsin D, all present in gastric carcinoma, has been determined by the peroxidase-antiperoxidase method on formalin fixed paraffin embedded sections of fetal stomach. Slow-moving protease appears to be the dominant enzyme from 12 weeks gestation onward, although progastricsin is also present at this time. Pepsinogen and cathepsin D do not appear until 17-18 weeks.

Aspartic Acid Endopeptidases↗
PubMed1987

The labile nature of the insulin signal(s) for the stimulation of DNA synthesis in mouse lens epithelial and 3T3 cells.

A kinetic study was carried out to assess the stability of the intracellular signal(s) generated by insulin in quiescent cells for the stimulation of DNA synthesis. Using murine lens epithelial cells and Swiss 3T3 cells in culture, it was found that insulin stimulated DNA synthesis after a lag of 14.5 h. If, however, 6 h after the addition of insulin to the cells, the insulin-containing media were totally removed, followed by the addition of fresh media (even if insulin was returned to the medium within approximately 10 min), a 14.5-h lag still remained after insulin readdition before DNA synthesis started. In another set of experiments, the insulin was removed after 6 h by diluting its concentration approximately 60,000-fold. In this case, if insulin was at the diluted concentration for approximately 60 min before being added back, a full 14.5 h was necessary for the start of DNA synthesis. The half-time for loss of signal was 2 +/- 1 min for total washout and 18.4 +/- 0.5 min for the dilution experiment. These results indicate that the intracellular signal(s) for DNA synthesis produced by the binding of insulin to its cellular receptor are extremely transitory in nature. The signal disappears at approximately the same rate that insulin dissociates from the receptor. Thus, insulin must be constantly binding to the membrane receptor in order to keep the key signal(s) at a high enough level for the cell to progress on to S phase. Early events, such as specific protein synthesis, changes in ion flux, changes in cellular metabolism, and changes in cellular pH, may be essential, but they are not sufficient to cause a cell to progress on to S phase. Addition of sodium vanadate to the cell is found to stabilize the messenger such that there is no loss of signal when insulin is removed. These data are consistent with the tyrosine-phosphorylated insulin receptor or a product of its action being the signal.

Animals↗
PubMed1987

Continual audit of clinical diagnostic accuracy by computer: a study of 592 autopsy cases.

In a prospective study of 592 autopsy cases, correlations between clinical and pathological data were made by computer from a novel protocol on which morphological and functional diagnoses were separated. The accuracy of diagnosis was analysed with respect to time in hospital, specialty, consultant in charge, and other criteria. Overall, there were 168 clinical 'overdiagnoses', not confirmed at autopsy; 492 'underdiagnoses', not made clinically; and 432 'agreements' between clinical and pathological diagnoses. The computer program allows the data to be analysed at any time as the number of cases increases. Entry of information entails comparatively little extra work and a similar system could be incorporated into the service commitment of any pathology department with a suitable microcomputer and access to a mainframe computer.

Autopsy↗
PubMed1987

The effect of diffusion on the immunolocalization of antigen.

Diffusion prior to tissue fixation may result in immunohistochemical localization of antigen at sites in which it does not occur in vivo. The extent and speed with which this may occur have been investigated with several antigens of different molecular weights in tissues which were left unfixed for various lengths of time. There was clear evidence of diffusion when fixation was delayed for as little as 1 h, resulting in focal labelling of cells which did not contain antigen in rapidly fixed tissues. Falsely localized antigen was particularly evident adjacent to sites containing high antigen concentrations and might be expected in areas permeated by antigen-containing tissue fluid. These findings substantiate the view that diffusion of antigen should be considered as a cause of false positivity in any immunolocalization study.

Animals↗
PubMed1987

Cost effectiveness of routine postmortem histology.

In a retrospective study of the records of 160 necropsies it was found that, according to the clinical and gross necropsy findings, no clinically important abnormality would have been anticipated in 46% of the tissue samples. The estimated annual cost of processing this material alone was pounds 10,500, including the salary of one full time medical laboratory scientific officer (MLSO). Few of the microscopic findings led to a change in diagnosis. It is suggested that unselected postmortem histology is, for diagnostic purposes, not cost effective.

Autopsy↗
PubMed1987

Slow moving proteinase. Isolation, characterization, and immunohistochemical localization in gastric mucosa.

Human gastric mucosa contains three immunochemically distinguishable aspartic proteinases, pepsinogen I (pepsinogen A), pepsinogen II (pepsinogen C, progastricsin), and a nonpepsinogen proteinase also termed slow moving proteinase (SMP). The properties of SMP, and in particular its relationship to another aspartic proteinase, cathepsin D, were examined in this study. Slow moving proteinase and cathepsin D were isolated, respectively, from gastric mucosa and human spleen. Antiserum specific to each proteinase was prepared in rabbits. Rabbit anti-SMP did not recognize cathepsin D, and conversely, anticathepsin D did not react with SMP. Immunohistochemical studies localized SMP to surface epithelial cells in both the fundic and pyloric gland areas of the stomach. In contrast, cathepsin D was found mainly in mononuclear cells in the lamina propria and in parietal cells. Slow moving proteinase exhibited considerably lower Km values for its interaction with two chromogenic substrates than did cathepsin D. An even greater distinction between the two enzymes was found with the protein inhibitor from Ascaris lumbricoides; the activity of SMP was inhibited very strongly, whereas that of cathepsin D was not affected. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis under denaturing conditions, SMP consisted of two subunits with apparent molecular weights of 42,500 and 41,000. The last two properties characterize a less-well-known aspartic proteinase, cathepsin E. We conclude that SMP is not cathepsin D, but that it may be cathepsin E.

Cathepsin D↗
PubMed1986

Schistosoma mansoni: salicylanilides as topical prophylactic against cercarial penetration of mice.

Salicylanilide and 37 of its analogs were applied topically to mice as candidate chemoprophylactic agents against Schistosoma mansoni cercarial penetration. The compounds were solubilized in absolute methanol, dimethyl sulfoxide, or isopropanol at concentrations not exceeding 1.25% W/V. The tails of the mice of each experimental group were treated by immersion for 5 min in the test compound solution or in the vehicle. The treated tails of 5 mice from each group were washed for 30 min in flowing tap water 3-4 hr after compound application. Tails of all mice were then exposed to approximately 100 cercariae by tail immersion for 1 hr, 24 hr after treatment. The portal veins were perfused 49 days after exposure and worm burdens were determined. The protective capacity of each compound was calculated by comparing the reduction of the mean worm burdens of the compound treated mice to the worm burdens of those treated with only the vehicle and expressing the resulting value as percentage protection. Of the 38 compounds tested, 20 provided 98% or better protection if the treated tails were not washed before exposure to cercariae. Of these 20 active compounds, 16 provided 98% or better protection from infection by S. mansoni cercariae even after the mouse tails were subjected to the 30 min wash.

Administration, Topical↗
PubMed1986

Necropsy study of mountaineering accidents in Scotland.

One hundred and twenty one people died in mountaineering accidents in Scotland between July 1978 and December 1983. Necropsies were carried out on 42, which form the basis of this report. In 21 cases head injury was major fatality factor, but in 11 of these there were also serious chest injuries. Focal brain damage (haematomas, contusions, or lacerations) was more common (n = 21) than diffuse brain damage (n = 18). Over half of the victims with severe head injury had few other injuries and would probably have survived had the head injury been prevented. Spinal injuries usually occurred with other major injuries. Chest injuries were common, being serious in 18 cases, but abdominal injuries were uncommon. Four climbers with only minor injuries died of hypothermia.

Abdominal Injuries↗
PubMed1986

Immunolocalization of cathepsin D in normal and neoplastic human tissues.

The aspartic proteinase cathepsin D was purified from human spleen and localised in various formalin fixed paraffin embedded human tissues using the peroxidase-antiperoxidase (PAP) technique. Cathepsin D was shown not only in macrophages but also in other connective tissue cells, and in epithelium. It was present in spleen (littoral cells and cells within Malpighian bodies), liver (hepatocytes and Kupffer cells), lung (alveolar macrophages and bronchial epithelium), brain (neurones), lymph nodes (histiocytes in germinal centres, sinusoid lining cells) and stomach (parietal and mucous neck cells). Cathepsin D was also found in carcinomas of bronchus, stomach, colon, kidney, breast, ovary, bladder and pancreas, both in neoplastic epithelium and in stromal cells, but was seldom present in connective tissue neoplasms. A group of malignant lymphomas also contained the enzyme within scattered cells. The distribution of cathepsin D seems to be much wider than that of the structurally related aspartic proteinases pepsin, gastricsin, and renin.

Brain↗
PubMed1986

Synchronized estrus and fertility of beef cows after weaning calves for short intervals.

In Exp. 1, the objective was to determine if interval of separating calves from cows (24 or 48 h) immediately before insemination affects detection and precision of estrus and pregnancy rates of lactating beef cows implanted with norgestomet. Separation of calves from cows for 24 h (n = 418) lengthened intervals to estrus, did not affect precision of estrus, reduced success of detecting estrus and lowered pregnancy rates relative to positive controls (48 h separation, n = 508). Cows with poor body condition, and not suckled for 24 h, conceived at lower rates than cows with similar condition that were not suckled for 48 h. Adverse effects of separation for only 24 h on fertility are apparently due to inadequate intervals between estrus and insemination at 48 h after removing implants. In Exp. 2, the objective was to determine effects of separating calves from cows for 48 h immediately before insemination on detection and precision of estrus and on pregnancy rate of ovulatory lactating beef cows injected twice with prostaglandin F2 alpha (PGF2 alpha). Weaning increased detection of estrus but overall pregnancy rates did not differ between suckled (n = 256) and nonsuckled (n = 221) cows. But, weaning calves improved pregnancy rates of young (2 to 3 yr) cows and reduced fertility among middle (4 to 6 yr)-aged cows. Increased pregnancy rates after weaning calves for 48 h are due largely to greater detection of estrus and inseminating more cows.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Synchronization of estrus in dairy heifers: a field demonstration.

Use of prostaglandin F2 alpha to synchronize estrus was demonstrated over 3 yr with 2966 dairy heifers in 45 herds. Reproductive status of all heifers was determined before any injections occurred. Anovulatory heifers (8.3%) were not injected or inseminated. Ovulatory heifers received one intramuscular injection and most heifers received two injections of prostaglandin F2 alpha spaced 11 d apart. Observations for estrus and insemination were scheduled and performed by dairy farmers. Insemination of heifers occurred 12 h after detection of estrus or at 80 h after second injection of prostaglandin F2 alpha. Pregnancy rate averaged 50.9% but varied from 0 to 100%. Pregnancy rate after insemination according to estrus (62.8%) was greater than when insemination was at 80 h (39.1%). Low pregnancy rates were associated with limitations in basic management of heifers before or during insemination. Managerial limitations were in timing insemination, range of ages or weights of heifers housed together, number and types of vaccinations, season and diet, frequency of observing heifers for estrus, and number of straws of semen thawed concurrently. Managerial factors that affect fertility are similar whether or not estrus is synchronized. Although agents used to synchronize estrus do not affect fertility directly, managerial limitations on fertility may be accentuated by increased intensity of activity associated with synchronization.

Animals↗
PubMed1985

Immunolocalization of prealbumin: distribution in normal human tissue.

Using an indirect immunoperoxidase staining technique we have demonstrated the plasma protein, prealbumin, in the cells of the pancreatic islets of Langerhans. Serial sections stained with antisera to glucagon, insulin and somatostatin revealed that the distribution of the prealbumin stained cells matched that of the glucagon A-cells. Absorption and cross-absorption experiments with prealbumin and glucagon showed that the staining was specific. We also found positive staining for prealbumin in single cells in the mucosa of the gastrointestinal tract, mainly stomach and colon, and kidney tubules.

Glucagon↗
PubMed1985

Gastricsin in the benign and malignant prostate.

An immunoperoxidase (peroxidase-antiperoxidase) method was used to localise the gastric acid proteinase gastricsin in prostate. The enzyme was present, probably as zymogen, in acinar lining cells in 66 (69%) of 96 cases of benign prostatic enlargement; other normal tissues from male genital tract were negative. It was also present in the tumour cells in 21 (39%) of 54 cases of prostatic adenocarcinoma. The findings support the suggestion that the prostate is the source of the gastricsin of normal seminal fluid. It is not yet clear whether its presence in prostatic carcinomas will be of diagnostic use.

Acid Phosphatase↗