PubMed Health⌕ Search

Biomedical subjects

J B Henry

Publications and source records attributed to J B Henry.

At least 19 recordsLinked to original sources
PubMed1992

Differential effects of intravenous hydralazine on myoendometrial and placental blood flow in hypertensive pregnant ewes.

OBJECTIVE: The differential vasoactive effects of hydralazine on the uteroplacental vascular bed were studied. STUDY DESIGN: After control measurements were taken, near-term chronically prepared pregnant sheep were continuously infused with angiotensin II. Maternal arterial pressure was increased by 32 mm Hg. Hydralazine was then administered; the effects on regional resistance and blood flow were evaluated with a radionuclide-labeled microsphere technique. Analysis of variance for repeated measures was used to compare observations. RESULTS: When compared with the hypertensive state, hydralazine caused the following changes by 40 minutes (mean +/- SEM): Although maternal blood pressure fell 31% +/- 5% (p = 0.0005), placental blood flow was unchanged, total uteroplacental blood flow increased 24% +/- 8% (p = 0.03), total uteroplacental resistance decreased 43% +/- 4% (p = 0.0002), placental resistance decreased 19% +/- 9% (p = 0.01), myoendometrial blood flow increased 390% +/- 82% (p = 0.0005), and myoendometrial resistance decreased 82% +/- 4% (p = 0.0005). CONCLUSIONS: In angiotensin II-induced hypertensive ewes, hydralazine is an effective dilator of the uteroplacental vascular bed and can maintain placental blood flow while blood pressure.

Adrenal Glands↗
PubMed1992

Medical futility. Committee on Bioethical Issues of the Medical Society of the State of New York.

The term futile is used in many different ways. It is therefore difficult to decide whether a procedure or treatment such as CPR or hemodialysis or blood transfusion would be futile in a given case. The AMA's guidelines on the appropriate use of DNR orders state that DNR decisions should be made openly. Institutions should have policies and physicians should elicit the patient's preferences about CPR. For physicians, the question is no longer whether we should discuss DNR orders with our patients; instead, the issue is how to do so with compassion and caring. Physicians should share with patients their judgment about what medicine can and cannot do. Then physicians must "make decisions about when to withhold or limit resuscitation openly" in honest and trusting conversation between doctor and patient. Often CPR is an exercise in futility. The medical profession should be vested with the authority to make futility decisions if they are the product of open discussion and shared deliberation between physician and patient, family, or surrogate. Rationing, triage, and medical futility in relation to AIDS patients require careful deliberation and consideration. What was considered medically futile five years ago for an AIDS patient may be appropriate care nowadays. The need for appropriate use or non-use of life-sustaining therapy for the elderly, the terminally ill, patients with AIDS and other incurable illnesses is evident to patients, health care providers, policy makers, and the public. CPR should only be administered if it is expected to confer lasting benefit to the patient. However, if 10% of elderly patients benefit from CPR in the case of out-of-hospital cardiac arrest, how can one consider this procedure futile? Although communication between physician and patient about difficult treatment limitation decisions has markedly improved in recent years, it remains a problem, largely because open dialogue with patients and families about futility is a demanding emotional and intellectual task. The medical profession is charged with setting standards for the proper implementation of judgments regarding futility.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Resuscitation↗
PubMed1990

Computers in medical education: information and knowledge management, understanding, and learning.

Desktop computers have evolved to permit physicians in practice and/or training to access and manage information to enhance knowledge, understanding, and learning. There are compelling reasons why the personal computer is key to learning and important in medical education. Above all, the computer enhances and amplifies the learning process. Using the desktop computer effectively is relatively easy. We teach our students to research information in books and journals and hope that, as practicing physicians, they do it even more to be current and maintain their competency. Why not a desktop computer to access and manage information, analyze it, and present findings? Computer technology is available to do virtually all of these tasks. Some tools are critical for medical students. For some time, all medical students have needed a black bag and microscope. Now every medical student needs a computer. Ample courseware is available and expanding rapidly for basic sciences and clinical disciplines. The explosion in biomedical information will continue. Finding information is key to understanding and learning rather than depending solely on memory, recall, or library trips for information. The desktop computer will benefit students, faculty, and future physicians and other health professionals as life-long learners.

Artificial Intelligence↗
PubMed1978

Expected hemotherapy in elective surgery. A follow-up.

Preoperative cross match guidelines were developed from a review of elective surgical hemotherapy. Six elective surgical procedures were studied prospectively to determine the effectiveness of the recommendations. All six procedures demonstrated a substantial reduction in preoperative cross match ordering during the study period, although for only one procedure was the guidelines' recommendation followed strictly. For those procedures that rarely required hemotherapy, an ABO-Rh typing and an antibody detection test were recommended as a preoperative study without a cross match. Through education of the clinical staff, successful establishment of these guidelines can lead to substantial monetary savings, reduced blood outdating, and a decreased blood bank workload with a more appropriate allocation of the technologists' time and effort.

ABO Blood-Group System↗
PubMed1978

Effective utilization of clinical laboratories.

Effective utilization of clinical laboratories requires that underutilization, overutilization, and malutilization be appreciated and eliminated or reduced. Optimal patient care service, although subjective to a major extent, is reflected in terms of outcome and cost. Increased per diem charges, reduced hospital stay, and increased laboratory workload over the past decade all require each laboratory to examine its internal operations to achieve economy and efficiency as well as maximal effectiveness. Increased research and development, an active managerial role on the part of pathologists, internal self-assessment, and an aggressive response to sophisticated scientific and clinical laboratory data base requirements are not only desirable but essential. The importance of undergraduate and graduate medical education in laboratory medicine to insure understanding as well as effective utilization is stressed. The costs and limitations as well as the accuracy, precision, sensitivity, specificity, and pitfalls of measurements and examinations must also be fully appreciated. Medical malpractice and defensive medicine and the use of critical values, emergency and routine services, and an active clinical role by the pathologist are of the utmost value in assuring effective utilization of the laboratory. A model for the optimal use of the laboratory including economy and efficiency has been achieved in the blood bank in regard to optimal hemotherapy for elective surgery, assuring superior patient care in a cost effective and safe manner.

Clinical Laboratory Techniques↗
PubMed1978

An improved technic for examining urinary casts and a review of their significance.

Casts represent an important, diagnostic component of urinary sediment, and may signal renal parenchymal disease in asymptomatic individuals. Accurate, precise identification of certain casts may be difficult due to poor visualization by current technics. Casts from freshly voided urine specimens, cytocentrifuged and stained by the Papanicolaou method, can be visualized optimally from permanent slide preparations. The genesis of these casts and their diagnostic potential related to renal disease and acute renal allograft rejection are discussed.

Erythrocytes↗
PubMed1978

Rapid amylase and lipase determinations by nephelometry.

The Coleman 91 nephelometer provides rapid, simple amylase and lipase assays, which are particularly suited to emergency requests. Linearity of amylase compares favorably with that of the Phadebas assay, and comparable precision was obtainable with serum and urine. Normal ranges for serum amylase are slightly higher than those based on the amyloclastic end-point assay. The serum lipase assay shows improved linearity over titrimetric procedures, although kinetics remain variably non-linear. Occasional sera show discordantly elevated nephelometric lipase and normal titrimetric lipase. Precision of the nephelometric lipase assay is somewhat lower than that of amylase; normal ranges are considerably higher than those based on titrimetry. Extremely lactescent sera may yield falsely low nephelometric amylase and lipase activities: these sera must be serially diluted to achieve actual values.

Amylases↗
PubMed1978

Transiently elevated apparent lipase by nephelometry.

Occasional patient sera showing normal or minimally elevated lipase activity in the 6-hour titrimetric assay and discordantly high lipase activity in the 6-minute nephelometric assay were encountered. Most of these sera had normal amylase activity. They represented about 1% of outpatient sera subjected to amylase assay. A few sera with discordant lipase activities showed elevated amylase activities and were from patients with the diagnosis of pancreatic dysfunction. Nephelometric lipase assay in these sera showed pronounced nonlinear kinetics; in the most discordant cases a gradual decay of initially high activity to zero occurred. Elevated nephelometric lipase activity was lost inordinately in serial dilution of serum or on serial reduction of undiluted assay volume. In tracer experiments, two of these sera liberated no significant amount of free fatty acids after extensive "de-emulsification" of the nephelometric substrate mixture. This nonlipolytic "deemulsifying" activity was found to be relatively heat-stable in one serum. The nature of this activity remains obscure. A simple and effective protocol is suggested to detect and identify these aberrant nephelometric lipases in the routine laboratory.

Amylases↗