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Biomedical subjects

W L Johnson

Publications and source records attributed to W L Johnson.

At least 19 recordsLinked to original sources
PubMed1992

Myocardial salvage with direct coronary angioplasty for acute infarction.

To assess the changes in myocardial function following direct coronary angioplasty, we evaluated 323 consecutive patients undergoing coronary angioplasty without antecedent thrombolytic therapy for acute myocardial infarction. Left ventricular function was evaluated using contrast ventriculography immediately preangioplasty and at the time of predismissal follow-up angiography (a mean of 7 days after infarction). The global ejection fraction increased from 52.6% to 58.9% (p less than 0.0005). Multivariate correlates of improved global left ventricular function included baseline ejection fraction less than or equal to 45%, and a patent infarct vessel at the time of predischarge follow-up angiography. Systolic function in the infarct zone improved by a mean of 30%. Logistic regression analysis identified sustained infarct vessel patency and anterior myocardial infarction as multivariate correlates of improved regional function in the infarct zone. In patients presenting with baseline ejection fractions less than or equal to 40%, the mean ejection fraction increased from 28% to 42%. Long-term survival was compromised in patients with global ejection fractions of less than or equal to 40% at the time of dismissal. Thus significant improvement in left ventricular function can be expected in the majority of patients undergoing direct infarct angioplasty. The myocardial salvage appears to be most significant in patients suffering large infarctions, and in those with sustained infarct vessel patency.

Aged↗
PubMed1992

Effects of compensatory growth on some body component weights and on carcass and noncarcass composition of growing lambs.

A trial was conducted in 1983 and repeated in 1984 to measure effects of restricted feed intake and realimentation on weights of organs and on carcass and noncarcass composition. A total of one hundred six weaned lambs from two breeds (Timahdit and D'man) and a breed cross (Ile de France x D'man) were used in both years. Lambs were allotted to one of six feed intake regimens: HH (ad libitum access to feed from 21 to 30 kg); HM (ad libitum access to feed from 21 to 26 kg then 70% ad libitum to 30 kg); MH (70% ad libitum from 21 to 26 kg then ad libitum to 30 kg); MM (70% ad libitum from 21 to 30 kg); LH (restricted to lose weight from 21 to 17 kg then ad libitum to 30 kg); and LM (restricted to lose weight from 21 to 17 kg then 70% ad libitum to 30 kg). Weights of visceral organs and mesenteric and kidney fat showed dramatic responses to alteration of feed allowances. After recovery from 20% live weight loss, weight of liver equaled or exceeded that of both the ad libitum and 70% refed lambs. Mesenteric and kidney fat did not. Refeeding was accompanied by an increase in water (P less than .05) and a decrease in fat (P less than .01) of both carcass and noncarcass components. These results indicate that weight loss of lambs incurred during feed shortage was largely in internal organ weights, and that these lambs can recover these losses during realimentation and undergo compensatory growth with better feed efficiency and lean carcasses.

Adipose Tissue↗
PubMed1992

Effects of undernutrition and refeeding on weights of body parts and chemical components of growing Moroccan lambs.

Forty-four intact, male lambs (20 Timahdit and 24 D'man) were used to assess the effects of 22% (from approximately 25 to approximately 20 kg) and 31% (from approximately 25 to approximately 17 kg) live weight loss and the subsequent refeeding to initial BW on changes in body components. Body composition was determined using a serial slaughter technique at 17, 20, and 25 kg live weight during normal growth, weight loss, and refeeding phases. Reduction in live weight from 25 to 20 kg was associated with greater loss of visceral organs (30%) and internal fat (75%) than carcass loss (19%). Further body weight loss (from 20 to 17 kg) involved carcasses to a greater extent than internal organs. The composition of BW loss consisted of 53% water, 28% fat, and 15% protein. Refeeding was associated with a rapid increase in organ weights and less fat regeneration. Although total internal organs recovered only 90% of their original weight, liver and kidneys regained all their weight. At the same slaughter weight, carcass and noncarcass components of refed lambs were leaner because of lower fat content in these components.

Adipose Tissue↗
PubMed1992

Orthopedic experience in a MASH unit in postwar Iraq.

The orthopedic experience of a U.S. Army MASH unit deployed in southern Iraq is discussed. Seventy major casualties were surgically treated in a short time span. A high percentage of extremity trauma was observed (69%). Many patients had multiple extremity involvement. The emergency wartime surgical treatment of four specific types of trauma is explored. A new algorithm is presented for the rapid evaluation of penetrating joint injuries. We summarize the current concepts of war surgery as they apply to orthopedic injuries, and add specific observations from this experience.

Hospitals, Military↗
PubMed1991

Safety and efficacy of percutaneous transluminal coronary angioplasty in patients with left ventricular dysfunction.

The risks and long-term outcome after 845 elective percutaneous transluminal coronary angioplasties (PTCA) in patients with left ventricular (LV) dysfunction (ejection fraction less than or equal to 40%) were examined. Procedural results were compared with 8,117 consecutive procedures in patients with ejection fractions greater than 40%. The patients with LV dysfunction were older (63 vs 60 years, p less than 0.01), had a greater incidence of prior myocardial infarction (84 vs 45%, p less than 0.001), prior bypass surgery (39 vs 21%, p less than 0.001), 3-vessel disease (62 vs 33%, p less than 0.001), and class IV angina (48 vs 41%, p less than 0.01) than the control group. Angiographic success was lower (93 vs 95%, p less than 0.01), and overall procedural mortality was increased ( 4 vs 1%, p less than 0.001) in the study group. Emergency surgery rates were identical (2%). No significant difference was found in rates of nonfatal Q-wave myocardial infarction (2 vs 1%). At mean follow-up of 33.5 months, 15% of the patients with LV dysfunction required late bypass surgery, 27% underwent repeat PTCA, and 59% were angina free. Actuarial survival at 1 and 4 years was 87 and 69%, respectively. Cox regression analysis identified 3-vessel disease, age greater than or equal to 70 years, class IV angina and incomplete revascularization as correlates of long-term mortality. These data suggest that PTCA may be an effective treatment for coronary artery disease in patients with LV dysfunction.

Adolescent↗
PubMed1979

Predictability of gestational hypertension.

Eighty-five women at 28-36 weeks' gestation were studied prospectively in a clinical research center to assess a "roll over test" (RT) based on the original study by Gant et al. Patients were admitted to the hospital, placed on bed rest, and given a balanced diet. The test started 12 hours after admission. Blood pressure was measured every 10 minutes for an hour with the patient in the left lateral position, and then in the supine position for a second hour. The mean diastolic blood pressure was calculated in each position and the patients were sorted into 6 groups based on the magnitude of change in blood pressure. Seventeen patients developed gestational hypertension (GH). Only 3 of 20 (15%) patients with a positive RT developed GH, while 14 of 65 (22%) patients with a negative RT developed GH. Five of 12 patients who had an actual decrease in mean diastolic blood pressure also developed GH.

Adolescent↗
PubMed1975

Pharmacologic control of uterine contractility. In vitro human and in vivo monkey studies.

The exact cause and mechanism of the onset of labor are unknown but the theories are many. There is considerable evidence that prostaglandins are potent stimulants of uterine activity and may play a role in the onset of labor. Prostaglandin release may be the natural mediator of uterine contractions during labor. A group of anti-inflammatory compounds (aspirin-like compounds) that inhibit prostaglandin synthesis include indomethacin and fenoprofen. Inhibition of prostaglandin production is a reasonable approach to inhibiting premature labor. An excised muscle strip technique was used as a screening procedure for pharmacologic depression of human uterine activity in vitro, testing isoxsuprine, mesuprine, Alupent, ritodrine, indomethacin, and fenoprofen. The prostaglandin antagonists indomethacin and fenoprofen exhibited marked depressant activity. These drugs were further tested in an in vivo rhesus monkey preparation measuring uterine activity, maternal blood pressure, uterine blood flow, fetal heart rate, fetal blood pressure, and blood gases. Fenoprofen is effective in reducing uterine contractility without serious maternal or fetal side effects and shows promise as a clinically effective agent for pharmacologic control of premature labor.

Adrenergic beta-Agonists↗
PubMed1975

Evaluation of human sera for antibodies against sperm by immunofluorescence.

Newborn cord sera and sera from pregnant women and from couples with unexplained infertility were observed by indirect immunofluorescence for reactions against human sperm. The sera from the infertile couples had been tested for macro-agglutination and complement-dependent immobilizing antibodies as well. Nonspecific fluorescence was noted only on the quatorial segment. Acrosomes and tail end-pieces were strongly immunofluorescent (positive at a serum dilution of 1:16) with 60 to 70% and 30 to 50%, respectively, of the sera from each main group, with the exception of the nonreactive cord blood. End-piece fluorescence was primarily due to the IgM globulin fraction. It is suggested that cord serum anti-sperm antibodies, directed mainly against the tail main piece, are due to IgG passively acquired from the mother. There was no apparent difference in immunofluorescence between infertile patients and control groups (except for the acrosome and end-piece, with cord sera). However, when the sera from infertile patients were subdivided into groups containing only agglutinating antibody, only immobilizing antibody, and both types of antibody, a higher percentage of the sera from the group having only agglutinating antibody reacted with all sperm areas. This reaction seemed more uniform over the sperm and included the usually negative posnuclear cap and midpiece. The other subgroups showed no obvious trends.

Acrosome↗
PubMed1975

Educational preparation for nursing--1974.

Each year a report of some of the most recent statistics on nursing education appears in the September issue of Nursing Outlook. The data presented are derived from The National League for Nursing's annual survey of state-approved schools of nursing in the 56 jurisdictions of the United States. The programs surveyed include those which prepare for beginning practice in nursing (baccalaureate, associate degrees, diploma, and practical nursing); those graduate programs that lead to masters and doctoral degrees in nursing; and those baccalaureate programs that conduct nursing programs for registered nurses only. Data on the status of state-approved basic schools (new schools, closed schools, and changes in existing schools) are obtained in September of each year from the state boards of nursing. In October, questionnaires are mailed to each school of nursing, as well as to those nursing programs that do not require state board approval (masters and doctoral programs, and baccalaureate programs for registered nurses). Information is also obtained from irregularly conducted surveys of all four-year colleges and universities in the United States that do not have state-approved basic nursing baccalaureate programs. The data obtained include admissions and graduations for the preceeding academic year, admissions for the current fall term, and enrollments as of October 15. Other information, such as data on men and minority students, is collected every three years. In recent years, enrollment figures for students who were admitted with advanced placement status have also been collected. With few exceptions, the schools have been most cooperative in providing the data, making it possible for us to obtain a 100 percent response rate for both registered nurse and practical nurse programs.

Education, Nursing↗