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Biomedical subjects

N Halpern

Publications and source records attributed to N Halpern.

17 recordsLinked to original sources
PubMed1999

Saccharomyces cerevisiae cells harboring the gene encoding sarcotoxin IA secrete a peptide that is toxic to plant pathogenic bacteria.

Sarcotoxin IA is a cecropin-type antibacterial protein produced by the flesh fly, Sarcophaga peregrina. Similar to other bactericidal small proteins produced by insects, sarcotoxin IA is released into the hemolymph of larvae and nymphs upon mechanical injury or bacterial infection. The gene (sarco) that encodes this toxin was introduced into Saccharomyces cerevisiae yeast cells and was expressed under a constitutive yeast promoter. The transformed yeast cells were grown in a liquid medium, and a peptide with a similar molecular size to that of the mature sarcotoxin IA was detected in the medium by Western blot analysis. The secreted sarcotoxin-like peptide (SLP) had a potent cytotoxic effect against several bacteria, including plant pathogenic bacteria, similar to the toxic effects of the authentic sarcotoxin IA. Erwinia carotovora was more susceptible to the toxic medium than Pseudomonas solanacearum and Pseudomonas syringae pv. lachrymans. Thus, yeast may be used in the production of such proteins for employment against various bacterial pathogens.

Animals↗
PubMed1995

Point-of-care testing in the intensive care unit. The intensive care physician's perspective.

Technological advancements have, for the first time, made the entire laboratory testing process feasible at the bedside. Physicians working in the intensive care unit have always had immediate access to patients' medical history, physical examination, and physiologic monitoring data, but had to wait for laboratory results. Using point-of-care testing, laboratory parameters targeted to critical illnesses can now be integrated into initial diagnostic assessments, on patient rounds, and during therapeutic maneuvers. The concept of point-of-care testing in the intensive care unit is relatively new, but as technology progresses, physicians will undoubtedly become aware and use it in the intensive care unit. This article focuses on the intensive care physician's perspective on laboratory testing, the evolution of the intensive care unit laboratory, advantages of point-of-care testing in that setting, new developments in arterial blood gas analyzers and monitors, and cost-effectiveness and incorporation of point-of-care testing.

Attitude of Health Personnel↗
PubMed1993

Descriptive analysis of critical care units in the United States: patient characteristics and intensive care unit utilization.

OBJECTIVE: To gather data about occupancy, admission characteristics, patients' ages, and types of therapy utilized in ICUs in the United States. DESIGN AND SETTING: Survey instruments were mailed to the administrators of 4,233 hospitals to gather information from the medical director of the institutions' respective ICUs for the purpose of developing a database on ICUs in the United States. The sampling frame for this study was based on all American Hospital Association (AHA) hospitals stating they had ICUs. MEASUREMENTS: Census questionnaires solicited information on occupancy, where the patients were admitted from, length of stay, therapies rendered, intensive care diagnoses, and resuscitation status, as well as other information. MAIN RESULTS: Data were obtained regarding 32,850 ICU beds, with 25,871 patients from 2,876 separate ICUs in 1,706 hospitals in the United States. The census response rate was 40% of the AHA hospitals that stated they had ICUs, with specific ICU data on 38.7% of the nation's ICUs. Overall, the responding units reported a mean occupancy rate of 84% of total bed capacity and 87% of available beds. As hospital size increased, so did ICU occupancy. Nearly 17% of all of the critical care patients had been in the units for > 14 days. More precisely, 49% of all responding units indicated that they had one or more "chronic" (> 14-day length of stay) patients. Most patients were admitted to the units from the emergency room (38%), operating room/postanesthesia care unit (22%), and the general hospital floor (16%). Neonatal units were exceptions to this observation, where most patients came from the delivery room (60%). Admission from other hospitals represented a significantly larger group of patients in the cardiac care, pediatric, and neonatal units. Respondents indicated that many of their current patients were elderly, with 43% of these patients aged 65 to 84 yrs and with 4% being > or = 85 yrs of age. The 47% of patients > or = 65 yrs of age increased to 58% when the neonatal and pediatric units were eliminated from the analyses. For all units responding to the survey, the leading primary admitting intensive care diagnoses were postoperative management, ischemic heart disorder, respiratory insufficiency/failure, and prematurity. Elimination of units predominantly treating children (pediatric and neonatal) from the analysis left "adult" units with three primary admitting diagnoses: ischemic heart disease, postoperative management, and respiratory insufficiency/failure with variation according to specific unit type. The leading diagnoses in pediatric units were respiratory insufficiency/failure, postoperative management, and congenital abnormalities. For neonatal units, prematurity was the primary admitting diagnosis, accounting for 59% of these units' patients. Respondents reported 5.3 +/- 10.9% of patients had received cardiopulmonary resuscitation (CPR) before admission into the critical care unit. Only 6.0 +/- 11.9% of patients in these critical care units had instructions that CPR not be performed while in the unit. CONCLUSIONS: This report should be viewed as the beginning step of an effort to improve both the information base available on critical care medicine and the performance of ICUs. Our survey findings provide an introduction into the everyday workings of critical care units throughout the United States. Research is required to determine which patients will benefit from intensive care and how to efficiently utilize the vast technology we have available for them in a world with limited financial resources, an aging population, and a multiplicity of societal and ethical concerns.

Adolescent↗
PubMed1992

Myocardial ischemia during the weaning period.

OBJECTIVES: To estimate the incidence of silent myocardial ischemia, its pattern over time and its relationship to the time and mode of weaning high-risk cardiac patients after noncardiac surgery. DESIGN: Prospective study with random assignment to one of three weaning modes. SETTING: A surgical intensive care unit in a university hospital and a Veterans Administration hospital. PATIENTS: Sixty-two patients meeting standard criteria for extubation were randomized to one of three modes of weaning: synchronized intermittent mandatory ventilation (n = 19), T-Bar (n = 21) or continuous positive airway pressure (n = 22). METHODS: Ischemia was monitored with a continuous two-lead (V5, III) ST segment analyzer. Tracings were reviewed by a cardiologist. Ischemia was defined as greater than 1 mm ST segment depression 60 milliseconds after the J point. The monitoring period included a prewean (mean 654.0 minutes), wean (mean 46.5 minutes) and postwean (mean 1223.4 minutes) period. RESULTS: Of 62 patients, 12 (19.3%) experienced ischemia at some time during the monitoring period, most often during the weaning period. Ischemia during weaning was detected in 3 of 21 (14.3%) T-Bar patients and 2 of 22 (9.1%) continuous positive airway pressure patients but in no synchronized intermittent mandatory ventilation patients. CONCLUSION: This study demonstrates that silent myocardial ischemia occurs frequently in high-risk postoperative patients, with the highest incidence during weaning.

Aged↗
PubMed1991

Predeposit Autologous Blood Donation: a survey of patient attitudes.

Attitudes to autologous blood donation have been surveyed in a group of 38 postoperative bariatric patients. Only two patients (5%) declined to participate. Twenty-eight of 38 ( 70%) successfully predeposited autologous blood. Twenty-five of 28 donors (90%) had done so at the suggestion of their surgeon. Concern about contracting AIDS was the motivating factor in the majority of patients (21 patients = 55%). Lack of infectious complications in general was cited by an additional four (11%). All respondents would donate autologous blood in the future, and would recommend the procedure to others who were about to undergo elective surgery. There was an increase from 29% to 50% who stated that, following their autologous donation experience, they would consider being homologous volunteer blood donors in the future.

Journal Article↗
PubMed1989

Postural kinematics of trumpet playing.

This paper examines the effects of anthropometry on body posture of trumpeters playing in standing position. Sixteen virtuosi trumpeters were photographed while hitting three notes (low C, high F and high F sustained) during performance of musical tasks. Initial standing posture and anthropometric data were recorded. Six body segment angles were computed and a vectorial sum was obtained to describe whole body posture in neutral and playing conditions. Horn angle and dental overbite were also computed. Earlier results showed that the musical task has no effect on playing posture. One-way ANOVA showed notable differences between the neutral posture and the note-related playing postures. A multiple regression model showed that in addition to the note effect, anthropometric variables, mainly neck length, explain the changes in playing posture. Horn angle is determined by the dental overbite. The importance of the anthropometric variables in playing the more demanding notes indicate that anthropometry may act to constrain trumpeters' performance.

Adult↗
PubMed1988

Musculoskeletal demands on flamenco dancers: a clinical and biomechanical study.

The flamenco dancer acts on the floor like a drummer. The percussive footwork and vibration patterns created during dancing impose unusual demands on the musculoskeletal system. This study investigated the clinical and biomechanical aspects of this task. Using the electrodynogram and skin-mounted accelerometers, foot pressures as well as hip and knee vibrations were recorded in 10 female dancers after a thorough clinical evaluation. A health questionnaire was also distributed to 29 dancers. Foot pressures and acceleration data reveal the percussive nature of the dance. Some clinical findings, like calluses, are related to pressure distribution. Urogenital disorders, as well as back and neck pain, may be related to the vibrations generated by the flamenco dance form. The hip joint seems to absorb most of the impacts. "Vibration-pressure" diagrams are suggested as a useful tool for evaluating a dancer's biomechanical behavior, as well as the effect of floors and footwear on this behavior.

Adult↗
PubMed1983

Keyboard design through physiological strain measurements.

The physiologically tolerable range of positions for the joints of the upper extremities have been investigated for typing tasks by recording the myoelectric activities of the involved muscles. For long-term typing tasks a split keyboard is recommended allocating a key field to each hand. The fields should be rotated against each other in the horizontal plane and inclined laterally.

Journal Article↗
PubMed1983

Ketoconazole: a novel and rapid treatment for advanced prostatic cancer.

Ketoconazole is an orally administered broad-spectrum antifungal agent that acts through the inhibition of the steroid synthetic pathways. At high doses in humans ketoconazole can lower rapidly serum testosterone and maintain it in the castrate range with frequent administration. This property suggested that ketoconazole might be useful in the treatment of prostatic cancer. We report a case of prostatic cancer in which ketoconazole resulted in rapid and sustained reduction in serum androgens as well as rapid induction of a clinical remission. Ketoconazole may be a valuable agent in the treatment of prostatic cancer.

Aged↗
PubMed1983

Haemoproteus and Leucocytozoon infections in birds of the Oklahoma City Zoo.

A total of 222 birds, captive or free-flying in the Oklahoma City Zoo, were examined for blood parasites; 31 (14%) harbored Haemoproteus and/or Leucocytozoon. While 21% of the indigenous avifauna were infected, only 8% of the exotic bird species harbored haemoproteids and these parasites were also exotic to North America. There was no evidence to indicate that exotic infections were transmitted to native birds or vice versa.

Animals↗