Biomedical subjects
G M Stewart
Publications and source records attributed to G M Stewart.
Jaw mass in a pediatric patient.
The aneurysmal bone cyst is an unusual cause of a jaw mass in children. Left untreated, this relatively benign lesion can lead to deformity and destructive bone changes. We report a nine-year-old patient with a large untreated aneurysmal bone cyst, and briefly discuss the differential diagnosis of head and neck masses in children.
Use of topical lidocaine in pediatric laceration repair: a review of topical anesthetics.
OBJECTIVE: To determine whether application of topical aqueous lidocaine to a laceration attenuates the pain from the subsequent lidocaine injection in children. DESIGN: Prospective, double-blind study. SETTING: A large, urban, tertiary care children's hospital emergency department. PATIENTS: A convenience sample of 100 children, five to 16 years of age, presenting with simple lacerations over a six-month period. INTERVENTIONS: An unlabelled 3-ml solution of either 1% lidocaine or placebo (saline) was used to soak a Telfa pad (Kendall, Mansfield, MA) and then placed onto the laceration for 10 minutes. The wound was then injected with 1% lidocaine, irrigated, and sutured per standard emergency department protocol. Independent pain response was elicited from the patient and parent four times: before any intervention, after the soak, after the injection, and at the end of the procedure. Blood pressure and heart rates were recorded at the same intervals. RESULTS: Four patients were excluded. Of the 96 remaining patients, 46 received the placebo and 50 received lidocaine. Age, sex, race, and laceration length and location were similar between groups. Physiologic parameters did not differ between groups. For all four pain ratings, the independent variables of age, sex, race, and laceration length or location did not differ between groups. Topical lidocaine was ineffective in relieving pain from the injection. When groups were combined, a significant negative correlation was noted for age versus injection pain (P = .035), with older children reporting less pain from injection than younger children. CONCLUSION: For children, soaking a simple laceration with 1% lidocaine does not decrease pain from the subsequent lidocaine injection.
New types of cancer after basal-cell cancer.
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Series on the quality of health care.
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Conditions mistaken for child abuse: Part I.
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Conditions mistaken for child abuse: Part II.
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ADCC activity of monoclonal anti-D antibodies.
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Human placenta--an antibody sponge?
Maternal IgG antibodies in sera and placenta eluates were studied by a cellular enzyme-linked immunosorbent assay (CELISA) method. Antibodies were not detectable in any of the serum samples obtained before or after delivery from nine normal primigravid women. Antibody activity was, however, present in five of nine placental eluates and two of nine neonatal sera tested in CELISA. Lymphocytotoxic antibodies were not detected in any of the samples tested. These results support the concept that the absence of antibody activity in maternal sera may be caused by the immunosorbent effect of the placenta.
Autocrine regulation of casein turnover in goat mammary explants.
Local feedback control of milk protein secretion was investigated in goat mammary explants by measuring degradation of newly synthesized casein in the presence of a goat milk whey fraction. Reduced net synthesis of [3H]casein in the presence of the milk fraction was due, at least in part, to its degradation during secretion, suggesting that this process is under autocrine regulation.
Day-by-day variation in fibrinolytic activity and in mortality from ischaemic heart disease.
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Ratings of psychosocial stressors in adolescence using DSM-III Axis IV criteria.
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Reductive metabolism and hypoxia-selective toxicity of nitracrine.
The 1-nitroacridine nitracrine [NC,1-nitro-9-(dimethylaminopropyl-amino)acridine] is a potent hypoxia-selective cytotoxic agent in culture, but lacks activity against hypoxic tumor cells in vivo at therapeutically accessible doses. To clarify reasons for this failure in vivo the metabolism of NC was investigated in stirred suspension cultures of Chinese hamster ovary cells, in EMT-6 spheroids, and in mice. One major low molecular weight metabolite (identical to that generated by NaBH4/Pd/C reduction) was observed in hypoxic (less than 10 ppm O2) single cell suspensions, while [G-3H-acridinyl]NC formed trichloroacetic acid- and acetonitrile-insoluble macromolecular adducts (MA) at a rate seven-fold higher than in aerobic (20% O2) cultures. Formation of these adducts correlated with cytotoxicity under air or nitrogen, and hence may provide a dosimeter for NC-induced damage. Autoradiographic investigation of the distribution of MA in spheroids equilibrated with 5% O2 showed that the label was restricted to the outer cell layers rather than being localized in the hypoxic central region. Thus metabolic activation is probably too rapid, even in well-oxygenated cells, to allow adequate distribution to hypoxic microenvironments in tumors. In mice, levels of MA were higher in liver, kidney, spleen and lung than in Lewis lung tumors, indicating that oxygen concentration does not exert a dominant influence on relative rates of metabolic activation in vivo. The development of nitroacridines with useful hypoxic selectivity in vivo will require identification of analogs for which reductive metabolism is more completely inhibited at oxygen concentrations found in normal tissues.
Noncytotoxic antibodies to paternal antigens in maternal sera and placental eluates.
Noncytotoxic antibodies were detected in sera from 6 of 7 primigravid women during the first trimester of pregnancy. Such antibodies directed to antigens expressed on paternal B lymphocytes were detectable within the first 4-5 weeks of gestation. Antibody activity toward paternal B lymphocytes was also detected in 6 of 10 placental eluates, and in 3 of 10 predelivery and 2 of 10 postdelivery maternal serum samples. When B lymphocytes from umbilical cord blood were used as target cells, antibodies were detected in 5 of 7 placental eluates, and in 3 of 7 predelivery and 2 of 7 postdelivery serum samples. These antibodies also reacted with selected members of a normal B lymphocyte panel. The concept of an immunological enhancing mechanism in normal pregnancy is supported by these data.
The fetus as an allograft: evidence for protective antibodies to HLA-linked paternal antigens.
Non-cytotoxic antibodies to paternal B lymphocytes were detected in sera from 11 of 11 multiparous women and from 11 of 16 normal primigravidae during the first trimester of pregnancy. These antibodies were not, however, detected in sera from 9 of 10 women of comparable gestation at the time of spontaneous abortion. By means of a rosette inhibition assay, the difference in antibody activity between the primigravidae (mean 37.9 +/- 19%, median 36.5%) and the women subject to spontaneous abortion (mean 7.3 +/- 11.6%, median 0%) was statistically significant. This antibody activity was not directed to the known HLA specificities (HLA--A, B, C, or DR), but linkage to the HLA gene complex was suggested by family studies. These results provide evidence for an HLA-linked antigen system not defined by conventional tissue-typing techniques. Fetomaternal disparity at this antigenic site may be important for successful pregnancy.
Blood-pressure screening and supervision in general practice.
Since April 1975 all men aged 35-69 years registered with four general practices in west central Scotland have had their blood pressure checked whenever they visit the surgery. Although the practice locations range from rural to city centre and observers comprise receptionists, nurses, and doctors, a standard procedure has been adopted for the examination, recording, follow-up, and management of high blood pressure. The results confirm that raised blood pressure is common and often goes undetected. Even when hypertension is known, casual blood pressure readings often exceed accepted normal levels. The findings also show that a population may be routinely examined through normal contact with the family doctor, and that this can provide a convenient, acceptable, and effective means of detecting and reducing raised blood pressure.
Excess smoking in malignant-phase hypertension.
The smoking habits of 82 patients with malignant-phase hypertension were compared with those of subjects in three control groups matched for age and sex. Sixty-seven (82%) of the patients with malignant-phase hypertension were smokers compared with 41 (50%) and 71 (43%) of the patients in two control groups with non-malignant hypertension, and 43 people (52%) in a general population survey. The excess of smokers in the malignant-phase group was significant for men and women, together and separately, for cigarette smoking alone, and for all forms of smoking. There were no significant differences between the control groups. The chance of a hypertensive patient who smoked having the malignant phase was five times that of a hypertensive patient who did not. Twelve patients in the malignant-phase group had never smoked. All were alive three and a half years on average after presentation (range 11 months to seven years). Twenty-four (36%) of the smokers with malignant-phase hypertension died during the same period. The mortality rate was significantly higher among patients with renal failure, as was the prevalence of smoking. Eighteen patients with malignant-phase hypertension had a serum creatinine concentration higher than 250 mumol/l (2.8 mg/100 ml); 17 were smokers and one an ex-smoker. Eleven of these 18 patients died.It is concluded that hypertensive patients who smoke are much more likely to develop the malignant phase than those who do not, and that once the condition has developed it follows a particularly lethal course in smokers.