Biomedical subjects
A Lee
Publications and source records attributed to A Lee.
Health status of Ethiopian refugees in the United States.
The health status of 239 Ethiopian refugees in the United States was evaluated. Over 70 per cent were males 15-30 years old. Positive PPDs (purified protein derivative of tuberculin) were observed in 72 per cent and 3.4 per cent had abnormal chest x-rays. One patient had active tuberculosis. Other laboratory abnormalities included: intestinal parasites (36.7 per cent), anemia (14.9 per cent), eosinophilia (14 per cent), positive syphilis serology (7.5 per cent), and hepatitis B surface antigenemia (9.4 per cent). The most prevalent intestinal parasites were Giardia lamblia, Trichuris trichiura, and Schistosoma mansoni.
Campylobacter pyloridis gastritis I: Detection of urease as a marker of bacterial colonization and gastritis.
A method to detect the presence of Campylobacter pyloridis in dyspeptic patients is described. The test procedure involves placing a gastric pinch biopsy into a small amount of a solution containing urea and a pH indicator in the well of a microtiter tray. The method depends on the ability of C. pyloridis to hydrolyse urea and release an alkaline product (ammonia). The "microtiter biopsy urease test" is 100% specific for C. pyloridis and has a 91% sensitivity after 18 h reaction time. Seventy-five percent of positive biopsies had a reaction time of less than 1 h. The test may be used to predict the presence of antral gastritis; as well as marking the presence of the bacterium; with a positive predictive value of 96% and a negative predictive value of 73%. There was a positive correlation between the biopsy urease test results and the grades of both chronic and active antral gastritis. This test is simple and can be performed in the endoscopy clinic as the formulation of the reagent obviates the need for aseptic techniques.
Campylobacter pyloridis gastritis II: Distribution of bacteria and associated inflammation in the gastroduodenal environment.
The distribution of Campylobacter pyloridis in the stomach and duodenal bulb of two series of patients (n = 53) with dyspeptic symptoms was studied. In all patients where a comprehensive search of the stomach was conducted, C. pyloridis and active chronic gastritis were associated. That is, the presence of this organism anywhere in the stomach may be taken as a marker of active chronic gastritis within that stomach, although not necessarily at the site of bacterial detection. Two main patterns of colonization are proposed: C. pyloridis either colonizes normal antra and extends proximally along the lesser curvature and into the body with subsequent development of active chronic gastritis and/or the bacterium colonizes areas of chronic-only gastritis induced by other agents resulting in active chronic gastritis. As C. pyloridis may be limited to the antrum or body of any given stomach, it is necessary to biopsy both areas when looking for the bacterium.
Campylobacter pyloridis infection as possible complication of weight loss therapy.
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Campylobacter pyloridis, urease, and gastric ulcers.
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Randomised controlled trial of computer assisted management of hypertension in primary care.
The hypothesis that general practitioners would obtain better outcomes for patients with hypertension using a computer than doctors not using a computer was tested. Sixty family physicians were randomised to two treatment strategies. "Test" physicians completed a data collection form after each visit from a patient with hypertension and mailed the forms to the test centre for processing. Computer feedback on management was mailed to the doctors. This encouraged doctors to apply the "stepped care" protocol, supplied charts of diastolic blood pressure v time, and ranked patients' diastolic blood pressures by percentile. Letters were mailed to patients to remind them of appointments. "Control" doctors filled out the same data collection forms as test physicians, but neither doctors nor patients received computer feedback. Physicians who used the computer saw more patients per practice than control doctors (test 50 patients, control 40). For all patients the length of follow up was significantly longer in test practices (test 199 days, control 167), and a smaller percentage dropped out of active treatment in test practices (test 37.5%, control 42.1%). For patients with "moderate" hypertension of a baseline diastolic pressure of greater than 104 mm Hg the mean score of the last recorded pressure was below the goal of 90 mm Hg in test practices (88.5 mm Hg), but it failed to reach this goal in control practices (93.3 mm Hg). A greater average reduction of diastolic pressure was achieved in test practices (test 21.7 mm Hg, control 16.7 mm Hg). Though patients with "moderate" hypertension were better controlled in test practices than in control practices, the patients in test practices visited their doctors less often (test 13.3 visits per patient-year, control 17.4 visits). Among patients with newly detected hypertension test practices achieved a greater reduction in diastolic pressure than control practices (test 15.1 mm Hg v control 11.3 mm Hg) and more sustained control of hypertension (test 323 days per patient-year with a diastolic pressure of 90 mm Hg or less v control 259 days).
Endodermal sinus tumor of the mediastinum. A report of seven cases and review of the literature.
Primary mediastinal endodermal sinus tumor is rare, and to date only 49 cases have been described in the English-language literature. Seven new cases are reported. Light microscopic examination showed characteristic features including papillary, reticular, tubular and solid growth patterns, complete or incomplete Schiller-Duval bodies and intracellular or extracellular periodic acid-Schiff-positive material. Immunohistochemical studies showed alpha-1-antitrypsin in seven, alpha-fetoprotein in seven, keratin in six, and carcinoembryonic antigen in four cases. The beta subunit of human chorionic gonadotropin, albumin, fibronectin, and transferrin were not found in any case. Electron microscopic studies performed in four cases showed intracellular and extracellular basement membrane-like material, multiple large multivesicular bodies, desmosomes and microvilli. Mediastinal endodermal sinus tumor can and must be differentiated from poorly differentiated adenocarcinoma metastatic or extending to the mediastinum because of the distinctly different prognoses and therapies. In spite of modern chemotherapy, the prognosis of mediastinal endodermal sinus tumor remains poor. The single most important prognostic indicator is whether the tumor mass can be completely excised before or after chemotherapy.
Campylobacter pyloridis, urease, hydrogen ion back diffusion, and gastric ulcers.
Campylobacter pyloridis, a bacterium implicated as the aetiological agent of gastritis and possibly gastric ulcers, has a very high urease activity. The rapid hydrolysis of urea at intercellular junctions results in alterations in the milieu of the gastric epithelium preventing the normal passage of hydrogen ions (H+) from the gastric glands through the mucus to the lumen and permits back diffusion. A consequence of H+ back diffusion is hypochlorhydria and a predisposition to ulcer formation. Several conflicting reports on the physiology of normal, gastritis, and ulcerated stomachs are reconciled by this hypothesis.
Alveolitis after use of a leather impregnation spray.
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Campylobacter jejuni in broilers: the role of vertical transmission.
The role of broiler eggs in the transmission of Campylobacter jejuni to broiler grow-out flocks was investigated. Six breeder flocks supplying broiler eggs to hatcheries were examined for cloacal carriage of C. jejuni. Of 240 birds tested, 178 (74%) were C. jejuni-positive. Eggs from these birds examined for C. jejuni penetration of the egg shell indicated that 185 of 187 were campylobacter-free. Eggs from breeder flocks of unknown C. jejuni status were also examined for C. jejuni shell penetration. C. jejuni was not isolated from 142 eggs examined. A further 193 hatchery eggs incubated and hatched in the laboratory were campylobacter-free. Six farms containing the progeny of C. jejuni-positive breeder flocks were monitored. Eight hundred and forty birds from 14 flocks in these grow-out farms were campylobacter-free during their 6-week grow-out period. Experimental egg-penetration studies indicated that C. jejuni transmission via the egg is not easily effected. Of 257 eggs surface-challenged with C. jejuni, 162 hatched; all were campylobacter-free. Of 167 eggs injected with C. jejuni, 12 hatched; 2 of these were colonized with C. jejuni. Our data do not support a role for vertical transmission of C. jejuni in commercial broiler production.
Blood pressure in the puerperium.
Blood pressure was measured by random zero sphygmomanometer in the morning and afternoon for 5 days after normal delivery in a group of 136 previously normotensive women. The number of women studied each day varied from 32 to 125. The afternoon blood pressure was higher than the morning blood pressure (differences: 1.7 mmHg systolic, 2.6 mmHg diastolic; P less than 0.05). Both systolic and diastolic blood pressures rose for the first 4 days after delivery. The average rise over the whole period was about 6 mmHg systolic and 4 mmHg diastolic (P less than 0.05). A considerable number of previously normotensive women displayed elevations of blood pressure in the puerperium. Twelve per cent of all patients exceeded a diastolic blood pressure of 100 mmHg.
Respiratory depression--tidal volume or frequency?
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Campylobacter pyloridis and gastritis: association with intercellular spaces and adaptation to an environment of mucus as important factors in colonization of the gastric epithelium.
Stomach biopsy specimens from greater than 40 individuals with Campylobacter pyloridis-associated gastritis were examined by light and electron microscopy. The bacteria were consistently seen in two locations: within the gastric mucus and associated with intercellular junctions of gastric epithelial cells. C. pyloridis is suggested to be one of a broad group of spiral bacteria that are adapted to the peculiar niche provided by intestinal mucus. The spiral morphology and the form of motility of these organisms give them a selective advantage in a viscous environment. This point has been demonstrated in vitro by measurement of the velocity of clinical isolates in solutions of methyl cellulose of varying viscosity. The localization of C. pyloridis close to intercellular junctions is proposed to be due to the presence of preferred metabolites or growth factors, e.g., urea and hemin. All isolates show an extremely high urease activity and require hemin for growth.
High frequency jet ventilation in fat embolism syndrome.
The use of high frequency jet ventilation in the management of a patient with fat embolism syndrome is described. Its principal advantage over conventional intermittent positive pressure ventilation is a reduction in the amount of sedation necessary.
Accidental subdural catheterisation.
A case of accidental subdural catheterisation is presented, and its course is compared with previously reported subdural injections of local anaesthetic agents. The importance of obtaining proof of the site of malposition of an epidural catheter is stressed.
Mucus colonization as a determinant of pathogenicity in intestinal infection by Campylobacter jejuni: a mouse cecal model.
Human isolates of the intestinal pathogen Campylobacter jejuni have been shown to colonize mucus on the outer surface and deep within the intestinal crypts of gnotobiotic or germfree mice. The cecal crypts are preferentially colonized. A model of mucus colonization by C. jejuni in the mouse cecum has been developed, using antibiotic- and magnesium sulfate-treated specific-pathogen-free animals. These spiral-shaped bacteria colonize the mucus in a similar manner to the normal spiral-shaped microbiota. No evidence of adhesion to the intestinal surface was found with a wide variety of microscopic techniques. The campylobacters were seen to be highly motile in living preparations of gut tissue and rapidly tracked along intestinal mucus. Just as many of the normal spiral-shaped bacteria of intestinal surfaces can achieve close association with the epithelium through mucus association and do not adhere to the surface, C. jejuni colonizes the intestinal mucosa via mucus colonization. Thus, a major determinant of pathogenicity in intestinal infection with C. jejuni is proposed to be an ability to colonize intestinal mucus. The possession of specific adhesins is unlikely to be a significant determinant of pathogenicity. Better understanding of the mechanism of mucus association and the properties of the bacterium that are responsible will provide a basis for the rational selection of preventative measures. The model of mucus association in adult antibiotic-treated mice provides an opportunity for colonization studies with variant organisms and immunization studies.
Human tumor xenografts treated with recombinant human tumor necrosis factor alone or in combination with interferons.
We have studied the activity of recombinant human tumor necrosis factor (rHuTNF) on six different human tumor xenografts derived from primary breast and bowel tumors and maintained by passage in nude mice. When 5 micrograms rHuTNF was given daily intratumorally to mice with established (approximately, 0.5 cm) tumors, total tumor regression was observed by 3-4 weeks in three of six xenograft lines. In a further two lines tumor stasis or significant slowing of growth was seen. This antitumor action was not accompanied by any consistent macroscopic change in the tumor such as necrosis, but histological examination revealed tumor cell degeneration and a large peritumoral infiltration of host inflammatory cells after 4-7 days therapy. In contrast to these data, little effect was seen when the same dose of rHuTNF was administered i.p. to nude mice bearing these tumors. In only two of six lines was any significant slowing of tumor growth seen. A 5-fold increase in the i.p. dose resulted in improved activity on only one of two xenograft lines tested. Efficacy of the i.p. rHuTNF dose could, however, be enhanced by simultaneous administration of human interferon, alpha or gamma. No obvious signs of toxicity were observed at all rHuTNF doses administered and weights of control and treated mice at the end of the experiments were comparable.