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Biomedical subjects

M Crawford

Publications and source records attributed to M Crawford.

At least 199 records · Page 11Linked to original sources
PubMed1980

Experimental comparison of extradural and i.m. morphine.

Morphine sulphate 3 or 4 mg was administered to the extradural space in five volunteers. Morphine 10 or 15 mg i.m. was given as control. Extradural administration resulted in an increase of pain threshold in the legs but not in the forehead. There was no significant depression of carbon dioxide response or deterioration of co-ordination or short-term memory. I.m. morphine caused an increase in forehead pain threshold, depression of the carbon dioxide response and some deterioration of cerebral function. Extradural morphine caused urinary retention in four and inability to ejaculate in three of the subjects. The principal site of action of extradural morphine appears to be regional, at spinal cord level, but it appears that autonomic function as well as pain perception can be affected.

Adult↗
PubMed1977

[The perioperative myocardial infarct after aortocoronary bypass].

Two sets of criteria are developed for the diagnosis of perioperative myocardial infarction: 1) new, persistent Q waves and either an elevated 48-hour MB-CPK area or a positive pyrophosphate scan, 2) severe ischemic ST-T wave changes and both elevated MB-CPK area and a positive scan.

Coronary Artery Bypass↗
PubMed1977

Growth of human melanoma in nude mice: suppression by T-lymphocytes from the tumor donor: brief communication.

Human malignant melanoma cell lines established in tissue culture were successfully transplanted sc into BALB/c nude mice. The growth rate of the resulting tumors was significantly suppressed when lymphocytes from the patient in whom the tumor arose were injected iv into BALB/c nude mice at the same time as sc tumor transplantation, but inoculation with lymphocytes from a person without a tumor was ineffective. Cell separation identified T-lymphocytes as the active subpopulation. Growth of the tumors was also significantly suppressed by reconstitution of the mice with normal BALB/c lymphocytes; lymphocytes from BALB/c mice previously immunized against the melanoma line were not more effective than nonimmune lymphocytes in preventing tumor growth. Sera from normal BALB/c mice or BALB/c mice immunized against a human melanoma cell line effectively suppressed growth of that cell line in BALB/c nude mice if given at the time of tumor transplant. The results suggested that, whereas murine lymphocytes reconstitute the ability of nude mice to react to xenogeneic antigens on the human tumor, human lymphocytes showed greater specificity to autologous human melanoma-associated antigens.

Animals↗
PubMed1976

51Chromium-release microassay technique for cell-mediated immunity to mumps virus: correlation with humoral and delayed-type skin hypersensitivity responses.

Lymphocyte-mediated immune responsiveness to mumps virus was studied with use of a 51chromium (51Cr)-release microassay of lymphocytotoxicity to target cells persistently infected with mumps virus. The release of 51Cr from immune cells was found to be virus-specific and reproducible and correlated well with the presence of antibody but not with the magnitude of antibody levels. Delayed-type skin hypersensitivity and specific immune release of 51Cr did not correlate well, which suggests that the two events may be mediated by different populations of cells.

Antibody Formation↗
PubMed1975

The physiological effects of inhaling exhaled cigarette smoke in relation to attitude of the nonsmoker.

Fifty-six nonsmoking college students were exposed, in a closed environment, for a period of 20 minutes to the exhaled cigarette smoke of two smokers. After intervals of 5, 10, 15 and 20 minutes of being exposed to the exhaled smoke, heart rates and systolic and diastolic blood pressures were monitored. Differences between times on systolic pressure was the only statistically significant finding. The subjects were then divided into two distinct attitude groups: (1) those who objected ("disliked") to being in the presence of cigarette smoke, and (2) those who did not mind ("indifferent") being in the presence of cigarette smoke. Variances attributable to between groups was statistically significantly different for heart rate. The "dislike" group had the higher rate in comparison to the "indifferent" group. Between times was statistically different for both groups for systolic pressure. Between group systolic pressures were not significantly different. As expected, there was no significant finding concerning diastolic changes.

Attitude↗
PubMed1975

Influence of acute alterations in heart rate and systemic arterial pressure on echocardiographic measures of left ventricular perfornmance in normal human subjects.

To study the effects of acute alterations in heart rate and systemic arterial pressure on the mean velocity of left ventricular circumferential fiber shortening (Vcf) and on mean posterior wall velocity (Vpw), we performed ultrasound studies in 25 normal human subjects between the ages of 21 and 29 years. When heart rate was augmented by the administration of intravenous atropine from 64 +/- 2.2 (SEM) to 98 +/- 2.7 beats/min, mean normalized Vcf increased from 1.22 +/- 0.05 to 1.38 +/- 0.06 circumferences (circ)/sec(P less than 0.001). Mean normalized Vpw increased from 0.76 +/- 0.03 to 0.89 +/- 0.04 sec-1 (P less than 0.001). Mean Vcf and mean Vpw uncorrected for end-diastolic diameter increased in a similar fashion (P less than 0.01). After atropine administration, systemic arterial pressure was augmented by means of a phenylephrine infusion in 23 subjects by an average of 39 mm Hg (range 20-50 mm Hg). During the phenylephrine infusion, average heart rate decreased from 96 +/- 2.6 to 91 +/- 3.1 beats/min (NS), while mean normalized Vcf declined from 1.38 +/- 0.06 to 1.09 +/- 0.05 circ/sec (P less than 0.001) and normalized Vpw from 0.89 +/- 0.04 to 0.65 +/- 0.04 sec-1 (P less than 0.001). Nonnormalized velocities exhibited similar alterations (P less than 0.01). We conclude that in the normal human subject mean Vcf and mean Vpw are sensitive to acute alterations in heart rate and systemic arterial pressure. Thus, when ultrasound measures are used for serial assessment of left ventricular performance, the level of heart rate and systemic arterial pressure at which studies are obtained must be considered. Further, the sequential use of atropine and phenylephrine, as described in this study, provides an experimental model for the evaluation of the effects of drug treatment and other interventions on left ventricular performance in man.

Adult↗
PubMed1975

Evaluation of left ventricular performance in acutely ill patients with chronic obstructive lung disease.

Among 28 patients with chronic obstructive pulmonary disease (COPD) with increasing dyspnea, the resting mean pulmonary arterial wedge pressure was elevated (greater than 12mm Hg) in 4 and became abnormal with exercise in 3 other subjects. Stroke volume index was reduced (less than 36 ml/beat/M2) in 16 of 26 patients (62 percent). The resting pre-ejection period index was prolonged (greater than 144 msec) in 17 patients (65 percent), while the left ventricular (LV) ejection time index was reduced (less than 408 msec) in 23 patients (88 percent). The ratio of the pre-ejection period to the LV ejection time was within the normal range (0.309 to 0.381) in only 3 of 26 patients (12 percent). Echocardiographic measurements of LV function were normal in nine patients, seven of whom had one or more abnormal values for systolic time intervals (STIs). These data suggest that reduced LV filing results in abnormal values for STIs in patients with COPD, and therefore that in such patients STIs are not accurate indices of LV function.

Aged↗