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Biomedical subjects

R Graham

Publications and source records attributed to R Graham.

At least 199 records · Page 11Linked to original sources
PubMed1986

The 24 hours before hospitalization: factors related to suicide attempting.

Fifty-nine psychiatric inpatients were interviewed concerning the psychological and environmental events that occurred in the 24 hours prior to their hospitalization. Independent raters then performed a content evaluation of these accounts, allowing for comparisons among patients admitted for a suicide attempt, suicide ideation, or non-suicide-related complaints. Results showed that suicide attempters were more likely to have used alcohol or marijuana and less likely to have contacted a health care professional than suicide ideators, even when past history of suicide behavior was controlled for. Suicide ideators were more likely to have contacted a mental health professional. Implications for suicide risk assessment and intervention are discussed.

Adult↗
PubMed1986

Respiratory muscle energetics during endotoxic shock in dogs.

Respiratory muscle O2 consumption, lactate production, and endogenous substrate utilization during endotoxic shock were assessed in two groups of anesthetized spontaneously breathing dogs. In the endotoxin group (Escherichia coli endotoxin 10 mg/kg iv) and the sham group (saline iv), we sampled diaphragm, external intercostal, and gastrocnemius muscle tissue for glycogen and lactate concentrations before and after 3 h of the experimental period. Only in the endotoxin group did blood pressure and cardiac output decline significantly. Arterial O2 content did not change significantly during shock, whereas mixed venous, phrenic venous, and femoral venous O2 contents dropped to 8.0 +/- 1.1, 5.8 +/- 0.8, and 3.6 +/- 0.6 ml/dl at 60 min of shock, respectively, with little change thereafter. At 30 min of shock, femoral venous lactate rose higher than arterial values, whereas at 90 min of shock, onward, phrenic venous lactate was significantly higher than arterial concentrations. All muscle tissues showed significant lactate production and glycogen depletion after shock. In a second set of experiments we measured respiratory muscle blood flow during shock with radioactive microspheres. At 60 min of shock, diaphragmatic and intercostal blood flow rose by six- and twofold, respectively, whereas gastrocnemius blood flow declined significantly. We conclude that during endotoxin shock 1) the increased demands of the respiratory muscles are met by increasing blood flow and O2 extraction; 2) anaerobic metabolism and respiratory muscle substrate depletion, or both, may contribute to the observed fatigue.

Animals↗
PubMed1986

Transfer of immunity to Ostertagia circumcincta and IgA memory between identical sheep by lymphocytes collected from gastric lymph.

Sheep rendered immune to Ostertagia circumcincta were challenged with 50,000 larvae and lymphocytes were collected from the gastric lymph up to eight days after challenge. The cells were transferred intravenously to genetically identical worm-free sheep which, together with controls, were challenged with 50,000 larvae and killed nine days later. Cells obtained during the donors lymphoblast response to challenge transferred partial immunity, measured either as stunting or loss of worms. Significantly less immunity was transferred by cells collected either before or after this response. Thus the responding cells can mediate protective immunity to O circumcincta. On the other hand the donor sheep remained immune to their challenge infection despite being depleted of these functional cells, showing that their presence was not essential for immunity to be maintained. Comparison of the immunoglobulin A (IgA) concentrations in the gastric lymph of recipient and control sheep showed that a local IgA response had also been transferred. Enumeration of mucosal mast cells suggested that a mastocytosis had been transferred to the two recipients which were most immune to challenge.

Animals↗
PubMed1985

Torre-Muir syndrome. An association with isolated sebaceous carcinoma.

Three cases of Torre-Muir syndrome are described in which isolated sebaceous carcinomas were associated with internal malignancy. The first was a 66-year-old woman who had a sebaceous carcinoma in association with carcinoma of the uterus, two adenocarcinomas of colon, carcinoma of renal pelvis and bladder, and a squamous cell carcinoma of the skin. The second was a 78-year-old woman who had a sebaceous carcinoma associated with carcinomas of the colon, ovary, and pancreas. The third patient had a sebaceous carcinoma associated with breast cancer. The subject is discussed and the previously reported cases reviewed.

Abdominal Muscles↗
PubMed1985

Dental occlusal wear and degenerative disease of the temporomandibular joint: a correlational study utilizing skeletal material from a contemporary population.

Forty crania and mandibles with intact dentition exceeding twenty-six teeth and bilaterally intact condyle-fossa apparatus were evaluated for attrition and degenerative joint disease. The skeletal specimens all represent a twentieth-century contemporary American population from the Atkinson Skull Collection at the University of the Pacific School of Dentistry. While 23.1% of this sample exhibited some degree of erosive osseous degenerative wear involving the condyle or articular fossa and 76.3% exhibited occlusal tooth wear, no significant correlation between the degree of attrition and the severity of degenerative joint disease could be documented.

Adult↗
PubMed1984

Effect of hypoxic hypoxia on systemic vasculature.

Effects of hypoxic hypoxia (HH) on cardiac output (CO), CO distribution, arterial and venous pressure-flow curves, vascular compliance, vascular time constant (tau), and resistance to venous return (RVR) were evaluated on six dogs. The vascular bed was isolated into four compartments depending on venous drainage: superior vena cava (SVC), splanchnic, renal and adrenal, and the remainder of the inferior vena cava (IVC). Low arterial O2 content and PO2 produced a threefold increase in CO at the same mean arterial pressure and a significant redistribution of CO to the SVC. Arterial pressure-flow curves decreased their slope (i.e., flow resistance) by a factor of two in the IVC and renal beds and by a factor of three in the splanchnic and SVC beds. Venous pressure-flow curves for the animal also decreased their slope significantly. HH causes a twofold increase in venous compliance and in mean venous pressure; tau did not change, but RVR halved. Seventy percent of the CO increase is explained by the increase in mean venous pressure and 30% by the reduction in RVR.

Acid-Base Equilibrium↗
PubMed1984

Adverse responses to local anaesthetics.

Progressive challenge was used to investigate twenty-seven patients with a history of an adverse response to local anaesthesia. True allergy was detected in only one patient. The method does not exclude reactions to additives and preservatives in local anaesthetics. If preservative-free local anaesthetics are used for subsequent exposure in patients with no response to progressive challenge, subsequent exposure is safe. The possibility that some of these patients may be reacting to preservatives in the solutions cannot be excluded by such testing. Where possible preservative-free local anaesthetic preparations should be used for subsequent anaesthesia.

Anaphylaxis↗
PubMed1983

A comparison of triclosan and chlorhexidine preparations with 60 per cent isopropyl alcohol for hygienic hand disinfection.

Four detergent preparations containing triclosan; two alcoholic products, containing triclosan and chlorhexidine respectively, and a detergent preparation containing chlorhexidine were compared with 60 per cent isopropyl alcohol following a single hand wash using Escherichia coli as the test organism. In vitro tests indicated that all had a high activity against hospital pathogens. The triclosan-containing preparations exhibited a significant pathogens. The triclosan-containing preparations exhibited a significant residual activity. Experiments in volunteers showed that 0.5 per cent alcoholic triclosan was significantly more effective than all other preparations tested. All the detergent preparations had an effect similar to that of 60 per cent isopropyl alcohol. None of the seven products evaluated was significantly less bactericidal than 60 per cent isopropyl alcohol.

1-Propanol↗
PubMed1983

Dopamine, dobutamine, and phentolamine effects on pulmonary vascular mechanics.

The pressure-flow (P-Q) relationship of the pulmonary vasculature, in an isolated canine lobe perfused under classical zone II conditions, can be characterized by a rectilinear segment at high flow, a curvilinear segment at low flow, and a pulmonary arterial pressure (Ppa) that exceeds alveolar pressure at zero flow. This demonstrates the presence of critical closure in the pulmonary vascular bed. Effects of drugs on pulmonary vascular resistance (PVR) must take the normal P-Q relationship into account. We examined the effect of dopamine (D) and dobutamine (DB), alone and in combination with phentolamine (P), on the slope of the rectilinear segment of the P-Q curve (equivalent to vascular conductance), the extrapolated Ppa intercept (Ppai), and the Ppa at zero flow (Ppaz). Low-dose D (0.4-0.8 mg) and DB (1.0-5.0 mg) did not significantly alter any parameter from control. Higher-dose D (1.2-6.8 mg) and DB (13-38 mg) decreased vascular conductance 32.3 +/- 12.1 (SE) to 50.45 +/- 5.6% (P less than 0.05), and P alone increased conductance 12.0 +/- 2.6% (P less than 0.01) from control with no significant effect on Ppai or Ppaz. The change in conductance with D and DB alone was abolished when either drug was given in combination with P. Ppaz and Ppai decreased significantly from control with DB in combination with P when no significant effect on vascular conductance was noted. The results suggest that lung vessels determining changes in flow resistance are pharmacologically distinct from those subserving critical closure in the pulmonary vascular bed.

Animals↗
PubMed1982

Critical closure in the canine pulmonary vasculature.

The vascular pressure-flow (P-Q) relationships in zone II (West et al.) were studied in isolated canine left lower lobes, in order to characterize the total resistance in the pulmonary vascular bed with respect to incremental or flow resistance and critical closure. At each of five levels of static lung inflation, the P-Q relationship was curvilinear at low flow and rectilinear at higher flows. The slope of the linear portion was not significantly different at alveolar pressures (PA) = 5, 7, or 9 cm H2O, but decreased significantly at PA = 11 and 15 cm H2O ((P less than 0.05), indicating an increase in flow resistance. The pulmonary artery pressure (Ppa) fell to the same value at zero flow regardless of inflation level [10.1 +/- 1.0 (SD) cm H2O at PA = 5 cm H2O to 10.9 +/- 2.7 (SD) at PA = 15 cm H2O]. The Ppa intercept (Ppai), extrapolated from the linear portion of the P-Q curve and representing the average closing pressure for the vascular bed, increased from 16.0 +/- 1.8 (SD) cm H2O at PA = 5.0 to 26.5 +/- 4.4 (SD) cm H2O at PA = 15 (P less than 0.05) in a direct one-to-one relationship with the increase in PA. Since this results in a constant transmural gradient at the alveolar vessel level, these vessels must be the major fraction which undergo critical closure. Operationally defined vascular compliance, determined from the slope of a simultaneously obtained pressure-volume (P-V) curve, decreased significantly from 1.51 +/- 0.62 (SD) ml/cm H2O at PA = 5.0 H2O to 0.87 +/- 0.27 ml/cm H2O at PA = 15 cm H2O (P less than 0.05).

Animals↗