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Biomedical subjects

W Adams

Publications and source records attributed to W Adams.

At least 19 recordsLinked to original sources
PubMed1998

2,3-Butanedione monoxime (BDM) decreases sarcoplasmic reticulum Ca content by stimulating Ca release in isolated rat ventricular myocytes.

The effects of 2,3-butanedione monoxime (BDM) were examined using rat ventricular myocytes loaded with Indo-1 to measure the intracellular Ca concentration ([Ca2+]i). BDM (10 mM) produced a transient increase of the systolic Ca transient with no steady-state effect on its magnitude. This transient increase was more marked when BDM was applied after having decreased the external Ca concentration from 1 to 0.1 mM. There was a transient increase of resting [Ca2+]i in both quiescent and electrically stimulated cells. Prior application of BDM decreased the rise of [Ca2+]i produced by caffeine. In voltage-clamped cells the rise of [Ca2+]i produced by BDM was accompanied by a transient inward current attributed to the electrogenic Na-Ca exchange. The amount of Ca lost from the cell upon application of 10 mM BDM could be estimated either from the integral of the BDM-evoked current or from the reduction of the integral of a caffeine-evoked current and corresponded to about 50% of the sarcoplasmic reticulum (s.r.) Ca content. The decrease of s.r. Ca content and the transient potentiation of the systolic Ca transient suggest that BDM acts by stimulating Ca-induced Ca release. These effects must be allowed for when using BDM.

Animals↗
PubMed1998

Mucinous anal gland carcinoma with perianal Pagetoid spread.

We report a case of well differentiated perianal mucinous carcinoma with associated dysplasia of the adjacent anal gland epithelium. Anal gland dysplasia is only rarely demonstrable histologically in cases of adenocarcinoma of suspected anal gland origin. The tumor was not associated with chronic perianal abscess or fistula formation, which had been regarded as important in the pathogenesis of perianal mucinous carcinoma. There was associated, clinically unsuspected Pegetoid intra-epidermal spread of adenocarcinoma in the perianal skin.

Adenocarcinoma, Mucinous↗
PubMed1998

A comparison of three methods of measuring 99mTc-DTPA lung clearance and their repeatability.

The lung clearance of technetium-99m diethylenetriamine penta-acetic acid (99mTc-DTPA) is a measure of respiratory epithelial permeability. Many factors may contribute to the wide range of normal values, including the method of correction for background activity. The aim of this study was to compare three methods of analysis, including their repeatability. 99mTc-DTPA lung clearance imaging was performed on eight nonsmokers (age 32+/-2 yrs, forced expiratory volume in one second (FEV1) 102.8+/-3.3% predicted yrs, mean+/-SEM and seven smokers (age 46+/-4 yrs, p<0.01, versus nonsmokers; FEV1 88.9+/-8.9%, p<0.05 versus nonsmokers) on two occasions each. The smokers were asked to refrain from smoking for 12 h. An uncorrected analysis was compared with two methods corrected for recirculating background activity using an intravenous correction and inter-renal and shoulder background regions of interest. The uncorrected method gave higher mean values for 50% lung clearance of 99mTc-DTPA (t50) values than the inter-renal (p<0.001) and shoulder (p<0.001) methods of correction in nonsmokers and the inter-renal method gave lower values than the shoulder-corrected method (p<0.05). In smokers there was no difference. There were no differences in mean t50 values obtained on two separate visits. There was no difference in the repeatability of the three methods of analysis. The three methods of analysis produced comparable results with no differences in repeatability.

Adult↗
PubMed1997

Concurrent colonic adenocarcinoma and two ileal carcinoids in a 72-year-old male.

A case of synchronous rectal cancer and two small-bowel carcinoid tumours was recently encountered in a 72-year-old man. This will be presented and discussed with a literature review. It emphasizes the importance of the concept of synchronous malignancy within the gastrointestinal tract and that patients presenting with any gastrointestinal neoplasm, especially colonic cancer and carcinoids, should undergo thorough exploration of the peritoneal cavity and its organs at initial surgery.

Adenocarcinoma↗
PubMed1997

Safety and effectiveness of homemade and reconstituted packet cereal-based oral rehydration solutions: a randomized clinical trial.

OBJECTIVES: Parents may be deterred from obtaining commercial oral rehydration solutions (ORS) for their young children with acute diarrheal disease because of its availability and/or cost, especially if they are poor. We conducted a randomized clinical trial to determine 1) whether low-income parents could safely mix and administer cereal-based ORS (CBORS) both from ingredients commonly found in the home and from a premixed packet; 2) whether these CBORS were as effective in maintaining hydration as commercial glucose-based ORS; and 3) whether CBORS were more effective in reducing severity and duration of illness. METHODS: Children 4 to 36 months of age discharged from emergency departments and health centers with acute diarrheal disease were randomized to receive either homemade CBORS, reconstituted packet CBORS, or Pedialyte. A study nurse saw the child at home each day until the illness resolved, and obtained capillary blood for serum sodium at enrollment and at 24 to 48 hours; a sample of CBORS for sodium concentration; stool for pathogen analysis; and daily fluid intake, stool frequency, and weight. RESULTS: A total of 232 children were enrolled, of whom 203 (88%) completed the study. Two parents (3%) in the homemade CBORS group and one parent (1%) in the packet CBORS group made mixing errors resulting in a high sodium concentration (>100 mEq/L); their children refused the solution and had normal serum sodium values. Mean CBORS sodium concentration for the remainder of the homemade CBORS group was 60 +/- 10 mEq/L, and for the packet CBORS group, 54 +/- 13. Eighteen children (11%) had abnormal serum sodium values at presentation, which returned to normal in all groups in most cases. Three children (4.5%) in the homemade CBORS group, 4 (6%) in the packet CBORS group, and 1 child (1.4%) in the Pedialyte group failed therapy. Children refused to take homemade CBORS and packet CBORS (43% and 32%, respectively) more often than Pedialyte (9%), and those in the CBORS groups tended to take less ORS and total fluids. There were no significant differences among the three groups in incidence of daily vomiting or stooling, duration of diarrhea, or weight gain. CONCLUSIONS: CBORS do not offer a clinically significant advantage over glucose-based ORS. Homemade CBORS represent a treatment option in carefully selected cases, but it is not the safest alternative for regular clinical use.

Acute Disease↗
PubMed1996

Therapy for acute otitis media. Preference of parents for oral or parenteral antibiotic.

OBJECTIVE: To determine if parents prefer single-dose intramuscular (IM) therapy or standard 10-day oral therapy for treatment of acute otitis media (AOM). DESIGN: Parents were asked their preference at the time their child was enrolled in a randomized controlled trial comparing the clinical efficacy of single-dose IM ceftriaxone sodium with 10 days of oral amoxicillin and clavulanate potassium for AOM. Additional information was collected at days 3 to 5 and 14 to 16 after the initiation of the therapy. SETTING: Primarily private practices; 15 sites. PATIENTS: For this study, 648 children aged 3 months to 6 years were randomly assigned to receive IM (n=327) or oral (n=321) therapy. RESULTS: The groups were equivalent in all measured sociodemographic factors. At the time of enrollment, 85% of parents expressed a preference for single-dose IM therapy. At days 3 to 5, no differences were reported in days children were absent from school or day care, parental absence from work, or loss of sleep by children. However, more parents with children in the IM therapy group than in the oral therapy group reported loss of sleep by the parent (35% vs 26%, P=.02, chi(2)). At days 14 to 16, more parents with children in the IM group reported being "very satisfied" with the antibiotic (65%) compared with parents whose children were assigned to the oral therapy group (38%, P<.001). In comparing current therapy to past oral therapy for AOM, 71% of the parents with children in the IM therapy group reported more satisfaction with current therapy, in contrast to 21% of parents with children in the oral therapy group (P<.001). Of the parents, 83% indicated they would prefer single-dose IM therapy for AOM in the future. CONCLUSION: All of the parents prefer single-dose IM therapy for AOM over standard 10-day oral therapy.

Acute Disease↗
PubMed1996

Pooling of vertical disparities by the human visual system.

Two experiments are described in which the effects of scaling vertical disparities on the perceived amplitudes of dome-shaped surfaces depicted with horizontal disparities were examined. The Mayhew and Longuet-Higgins's theory and the regional-disparity-correction theory of Garding et al predict that scaling should generate a change in perceived depth appropriate to the viewing distance simulated by the scaled vertical disparities. Significant depth changes were observed, by means of a nulling task in which the vertical-disparity-scaling effect was cancelled by the observer choosing a pattern of horizontal disparities that made the dome-shaped surface appear flat. The sizes of the scaling effects were less than those predicted by either theory, suggesting that other cues to fixation distance such as oculomotor information played an appreciable role. In conditions in which 50% of the texture elements were given one value of vertical-disparity scaling and the remaining 50% were left unscaled, the size of the scaling effect on perceived depth could be accounted for by equally weighted pooling of the vertical-disparity information unless the two scalings were very dissimilar, in which case the lower scaling factor tended to dominate. These findings are discussed in terms of a Hough parameter estimation model of the vertical-disparity-pooling process.

Attention↗
PubMed1994

A perspective on the potential development of environmentally acceptable light-duty diesel vehicles.

Between 1979 and 1985, an international technical focus was placed upon potential human health effects associated with exposure to diesel emissions. A substantial data base was developed on the composition of diesel emissions; the fate of these emissions in the atmosphere; and the effects of whole particles and their chemical constituents on microorganisms, cells, and animals. Since that time, a number of significant developments have been made in diesel engine technology that require a new look at the future acceptability of introducing significant numbers of light-duty diesel automobiles into the European and American markets. Significant engineering improvements have been made in engine design, catalysts, and traps. As a result, particle emissions and particle associated organic emissions have been reduced by about 10 and 30 times, respectively, during the past 10 years. Research studies to help assess the environmental acceptability of these fuel-efficient engines include the development of an emissions data base for current and advanced diesel engines, the effect of diesel emissions on urban ozone formation and atmospheric particle concentrations, the effect of fuel composition, e.g., lower sulfur and additives on emissions, animal inhalation toxicology studies, and fundamental molecular biology studies.

Gasoline↗
PubMed1993

The problem of detecting changes in the incidence of schizophrenia.

Despite reports of falling first-admission rates for schizophrenia in the UK and other Western countries, it would be rash to conclude that the incidence of schizophrenia is falling. An attempt was made to tackle the many methodological problems and sources of bias influencing the relationship between admission rates and incidence in an analysis of inception rates for schizophrenia and other psychoses in Edinburgh between 1971 and 1989. However it was calculated, the inception rate for schizophrenia fell significantly, but because there was evidence that diagnostic criteria for schizophrenia had narrowed between 1971 and 1989, and because a substantial and changing proportion of recorded first admissions were not true first admissions, it was impossible to conclude that the incidence of schizophrenia had fallen. Changes in the incidence of psychiatric syndromes are difficult to establish, particularly in retrospect, and future studies must pay more attention to the many possible confounding influences.

Adult↗
PubMed1993

Epidemiological evidence that maternal influenza contributes to the aetiology of schizophrenia. An analysis of Scottish, English, and Danish data.

The epidemiological evidence that the offspring of women exposed to influenza in pregnancy are at increased risk of schizophrenia is conflicting. In an attempt to clarify the issue we explored the relationship between the monthly incidence of influenza (and measles) in the general population and the distribution of birth dates of three large series of schizophrenia patients--16,960 Scottish patients born in 1932-60; 22,021 English patients born in 1921-60; and 18,723 Danish patients born in 1911-65. Exposure to the 1957 epidemic of A2 influenza in midpregnancy was associated with an increased incidence of schizophrenia, at least in females, in all three data sets. We also confirmed the previous report of a statistically significant long-term relationship between patients' birth dates and outbreaks of influenza in the English series, with time lags of -2 and -3 months (the sixth and seventh months of pregnancy). Despite several other negative studies by ourselves and others we conclude that these relationships are probably both genuine and causal; and that maternal influenza during the middle third of intrauterine development, or something closely associated with it, is implicated in the aetiology of some cases of schizophrenia.

Adult↗
PubMed1992

Effect of an omental wrap on the healing and vascularity of compromised intestinal anastomoses.

Adult Wistar rats were used to investigate the ability of an omental wrap to limit leakage from compromised intestinal anastomoses. Under ketamine anesthesia, a section of small bowel was divided and then reanastomosed using a "control" anastomosis, a "deficient" anastomosis, or an "ischemic" anastomosis, plus or minus the addition of a wrap of omentum. Initially 10 rats were randomly assigned to each group. Nineteen of the 20 rats with unwrapped compromised anastomoses died within six weeks, compared with five deaths in the rats protected by an omental wrap (Fisher's exact test; P less than 0.01). The experiment was then repeated with a sample of rats from each anastomotic group being sacrificed for histologic examination on days 2 to 7, 10, 14, and 42. At the time of sacrifice a dye was injected into the omental vasculature to determine its contribution to the healing anastomosis. An anastomosis could be demonstrated between omental and bowel wall vessels by the third postoperative day. At one week the infarcted bowel edges were being resorbed and the omentum formed a fibrotic cylinder aligning the separated ends of bowel wall. At six weeks the scar became more contracted and the bowel mucosa had started to grow onto its luminal surface. It is concluded from this study that the omental wrap is protective to a compromised anastomosis by providing a biologically viable plug to prevent early leakage and a source of granulation tissue and neovasculature for later wound repair.

Anastomosis, Surgical↗
PubMed1992

Ocular pulsation correlates with ocular tension: the choroid as piston for an aqueous pump?

In 26 random out-patients, including 13 treated glaucoma patients and ocular hypertensives, the higher the ocular tension, the greater the pulse amplitude, by Alcon pneumotonometry, at a statistically significant level. In a single untreated hypertensive, when 2-hourly pneumotonometry was done for 24 h, the correlation was similar and significant. The higher the diastolic blood pressure, the higher the ocular pulsation, also significantly. Pulsation is suggested to be a pump, the choroid being the piston, contributing (1) to an increase in the outflow of aqueous humour and (2) to a homeostatic mechanism contributing to normalization of the intra-ocular pressure, wherein pulsation increases or decreases, as the intraocular pressure increases or decreases, respectively.

Aqueous Humor↗