Biomedical subjects
R Graham
Publications and source records attributed to R Graham.
What is dermatosis papularis nigra?
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What is pityriasis rosea?
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What is a dysplastic naevus?
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In vitro fertilization of mouse ova by spermatozoa exposed isothermally to radio-frequency radiation.
Mouse spermatozoa were exposed in vitro for 1 h to 27- or 2,450-MHz CW RF radiation at SARs of 0 to 90 W/kg under isothermal (37 +/- 0.2 degrees C) conditions. Exposure at either frequency to RF radiation at SARs of 50 W/kg or greater resulted in a statistically significant reduction in the ability of irradiated sperm to fertilize mouse ova in vitro (P less than .05). Over the range of SARs there was no apparent difference in the effects of 27- vs. 2,450-MHz RF radiation. There were no readily detectable exposure effects on spermatozoan morphology, ultrastructure, or capacitation. The reduction of in vitro fertilization is attributed to a direct effect of RF radiation on spermatozoa rather than to heating.
Two sources of contamination of a hydrotherapy pool by environmental organisms.
As a result of occasional water discolouration, the hydrotherapy pool of a large teaching hospital was monitored for free and combined chlorine, alkalinity, calcium hardness, total dissolved solids and cyanuric acid levels together with bacteriological analysis. The hose pipe supplying the pool and the dual water pumps were also examined as potential sources of bacterial contamination. The pool water yielded high counts of Pseudomonas vesicularis, Pseudomonas aeruginosa, and CDC Group IV C2, even in the presence of adequate levels of free chlorine. This was found to be due to high concentrations of cyanuric acid which resulted in a 'chlorine lock'. The source of the P. vesicularis and CDC Group IV C2 was found to be the pool hose and this problem was alleviated by flushing it with water each day before use. The source of the P. aeruginosa was the pool pumps, and was eradicated by regularly shock dosing them with 6-8 ppm of free chlorine.
Iliac artery aneurysms presenting as large pelvic masses.
Iliac artery aneurysms are rare but potentially lethal. Radiographic diagnosis is imperative as they can be asymptomatic. Five cases of iliac artery aneurysms are presented.
Audit of the activity of a same day ward.
OBJECTIVE: To assess the utilization of a 16-bed same day ward with particular reference to preadmission, discharge and after-care planning, and complication and delayed discharge rates. METHOD: Three audits, each of 200 consecutive patients, were carried out during 1987 with a questionnaire suitable for desk-top data processing. RESULTS: The same day ward was capable of being used by a wide variety of disciplines, with one in five patients aged more than 70 years. Significant falls in complication and delayed discharge rates occurred, with increasing use of discharge notes and follow up arrangements by medical staff. Preadmission visits by a community nurse may facilitate the appropriate use of the ward by elderly patients.
RBRVS: four perspectives.
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Primary adenocarcinoma of the jejunum.
Experience with primary adenocarcinoma of the jejunum at the Union Memorial Hospital is reviewed. Six patients treated from 1968 to 1986 with this interesting but rare tumor were identified. Although symptoms appeared to be of long duration, all patients were diagnosed with advanced disease, with only one patient surviving long-term. Data on primary jejunal adenocarcinoma reported in the medical literature were reviewed. The survival figures appear to correlate with stage at presentation, and therefore early and aggressive diagnostic and therapeutic intervention seems indicated to improve the outlook in these patients with historically poor survival rates.
The aftermath of a strike: "Everyone lost". Interview by Alden Solovy.
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Modulation of tendon fibroplasia by exogenous electric currents.
A chicken tendon explant model system has been developed to investigate the effects of extremely-low-frequency (ELF), low-amplitude, unipolar, square wave pulsed electric fields on fibroplasia in vitro. An electric field parameter set consisting of 1-Hz, 1-ms duration pulses, with a time-averaged current density of 7 mA/m2 (peak current density 7 A/m2) induced maximal (32%) increase in fibroblast proliferation in tendon explants exposed for 4 days. Exposure to the same field at an average current density of 1.8 mA/m2 had no effect on fibroblast proliferation, whereas exposure to current densities on greater than 10 mA/m2 inhibited proliferation and relative collagen synthesis, without affecting noncollagen protein synthesis. Fibroplasia was significantly increased in explants oriented parallel to applied electric fields having current densities of 3.5 or 7 mA/m2, but there was no detectable effect on explants oriented perpendicular to the same electric field. Fibroblast proliferation and relative collagen synthesis were inversely proportional to donor age for chickens in the 3- to 16-week age group used in this study. For these dependent variables (proliferation and relative collagen synthesis), there was no interaction between donor age and ELF electric field exposure.
In vitro activity of florphenicol.
Florphenicol was active at a lower concentration than chloramphenicol against over half of 234 recent clinical bacterial isolates. The majority (98%) of the isolates were inhibited by florphenicol at a concentration of 8 mg/l or less. Florphenicol was particularly effective against chloramphenicol resistant strains of Haemophilus influenzae. Klebsiella aerogenes and Bacteroides spp. Florphenicol was bacteristatic for salmonellae and Escherichia coli but bactericidal for Haemophilus influenzae. Florphenicol was slightly more active than chloramphenicol against Chlamydia trachomatis, Mycoplasma hominis and Mycoplasma pneumoniae but less active against Ureaplasma urealyticum.
The effect of hypertension, sodium, and race on isoproterenol sensitivity.
The heart rate response to isoproterenol is felt to be an index of beta receptor sensitivity. We studied this response in 55 normotensive and mildly hypertensive men on two dietary salt intakes (10 meq sodium per day, and 200 meq sodium per day). There was no relationship between receptor functioning and diagnosis of hypertension. Similarly, age, relative body weight, and resting plasma catecholamines were unrelated to the heart rate response to isoproterenol. There was however, a significant three-way interaction between race, diagnosis, and dietary salt. Black hypertensives fail to down regulate their beta receptors' response to isoproterenol in the face of a high salt challenge (p less than .006).
Prophylaxis against Pneumocystis carinii pneumonia in patients receiving azidothymidine.
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Inverted papilloma: an uncommon benign cause of a ureteral filling defect.
A case of inverted papilloma of the ureter in a 62-year-old man is presented along with a literature review of 14 cases. This rare benign tumor should enter the differential diagnosis of a ureteral filling defect especially when it has a smooth configuration. Preoperative consideration of this diagnosis may lead to intraoperative confirmation of pathology and conservative resection.
Acquisition of endemic Pseudomonas aeruginosa on an intensive therapy unit.
During a 9-month period, patients, staff and environment were monitored in order to trace the source of endemic Pseudomonas aeruginosa on our intensive therapy unit (ITU). Of 81 patients studied, 14 (17%) acquired 15 different pyocin types while on the ITU. The most frequent site of colonization was the rectum (11 patients). Rectal strains subsequently appeared in urine (two patients), wound (one) and sputum (four) of six patients. Three episodes of cross-infection (wound (two), urine (one] occurred without development of rectal colonization. Strains isolated from the environment and staff were not implicated. While gastrointestinal carriage of P. aeruginosa may not be detected on admission to the ITU, excessive use of antibiotics may be responsible for apparent acquisition of the organism followed by endogenous transfer of the rectal strains to other sites of the body.
Effects of norepinephrine and fluid administration on diaphragmatic O2 consumption in septic shock.
The effects of norepinephrine infusion and fluid administration on diaphragmatic O2 consumption during endotoxic shock were assessed in spontaneously breathing anesthetized dogs. Blood flow was measured with the microsphere technique, and diaphragmatic venous blood was obtained via a catheter inserted into the left inferior phrenic vein. One group of dogs (n = 6) received 10 mg/kg Escherichia coli endotoxin intravenously (E group). In the second and third groups, blood pressure after endotoxin injection was restored by continuous infusion of norepinephrine tartrate (N group) or by infusion of normal saline and dextran infusion (F group). The animals were observed for 2 h after endotoxin injection. Cardiac output fell significantly in the E and N group, whereas it was restored in the F group. Minute ventilation and diaphragmatic pressure-time index rose twofold in the three groups of dogs. Diaphragmatic O2 consumption (VO2 di) increased substantially in the E group to a mean value of 3.46 ml X 100 g-1 X min-1, which was achieved by higher blood flow and by an increase in O2 extraction. In the N group, VO2 di was higher than control but was lower than that of the E group (mean value of 1.43 ml X 100 g-1 X min-1), which was achieved solely by increasing O2 extraction. In the F group, VO2 di was also lower than that of the E group (mean value of 1.51 ml X 100 g-1 X min-1), which was achieved by high diaphragmatic blood flow. Thus, at any given diaphragmatic task, the diaphragm consumed less O2 in the N and F group than in the E group.