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Biomedical subjects

S Wolf

Publications and source records attributed to S Wolf.

At least 487 records · Page 27Linked to original sources
PubMedDate not supplied

Disorders of cardiac conduction accompany the dive reflex in man.

The faces of 19 healthy subjects were immersed in water at the temperatures varying between 10 degrees and 30 degrees C and at different degrees of lung inflation. Several abnormalities of cardiac conduction were noted. They occurred with the greatest frequency in the coldest water and when there was relatively little air in the lungs at the moment of immersion. There was fragmentary evidence, confirmatory of earlier studies, that heart-rate slowing was accentuated by fear and that very little slowing occurred when the subject was distracted or preoccupied. Various conduction abnormalities were recorded. The most striking finding was the wide difference from person to person in the occurrence of conduction disturbances under more or less comparable circumstances. Moreover, the patterns of conduction alterations, differing from person to person, were nevertheless relatively consistent from dive to dive for the same individual. To ascertain whether or not such idiosyncratic responses may have prognostic significance calls for a long-term, prospective study.

Adult↗
PubMedDate not supplied

A preliminary study in medical anthropology in Brunei, Borneo.

Nine rural village communities in the jungle of Brunei, Borneo were studied to ascertain possible effects of rapid social change on the health of the inhabitants. The social mores and religious beliefs of the rural tribes--Iban, Dusun, and Punan--have undergone but little change over many hundreds of years. During the past three decades, however, enormous social pressures for change have envolved from extraordinary economic prosperity of the region, due to the exploitation of large discoveries of oil and gas. Much of the money has been invested in health care, with the result that malaria, typhus and other tropical scourges have been virtually wiped out. Child and maternal mortality have been reduced to the standards of some of the healthiest countries in the world. The young of the formerly illiterate population are being rapidly educated in new schools scattered throughout the nation. New roads are penetrating the jungle and a thriving lumber industry has been established. Motor boats for the rivers, T.V. and even a national airline have been added. Despite these incursions a vigorous proseletizing by the Moslem and to a lesser extent by the Christian church, the villagers have held tenaciously to their ancient animistic beliefs. Living in long houses, they have also been able to maintain a tightly cohesive patriarchal family structure. Against this background there is as yet little or no evidence of the major diseases of Western society--coronary artery disease and hypertension, although most forms of cancer are commonly encountered. Brunei offers a splendid opportunity to test the putative relationship of chronic vascular disease to social structure and a way of life. Future studies may be made prospectively as the almost inevitable breakdown of old customs and patterns of living occurs in the face of rapid modernization.

Anthropology↗
PubMedDate not supplied

Cost reduction after introduction of a multidisciplinary infectious disease service at a German university hospital.

BACKGROUND: In 1997 an infectious disease service (IDS) similar to those in the US was established at a university hospital in Munich, Germany. PATIENTS AND METHODS: We assessed the economic impact of the new policy by performing a cost comparison analysis. Inpatients with pneumonia, skin infections/cellulitis, urinary tract infections (UTI) and bacteremia/sepsis were assigned to two groups: patients from a 6-month period after the establishment of the IDS (post-IDS group) were compared with similar patients before the implementation of the ID-service (pre-IDS group). Costs of microbiological investigation (MB), antibiotic treatment (AB), clinical imaging (CI), total costs and length of antibiotic therapy were analyzed. RESULTS: Patients with UTIs in the post-IDS group had 39% fewer MBs (p<0.05) than patients in the pre-IDS group, resulting in a 33% decrease in average MB costs (p<0.05). In the total group, in which subgroups with pneumonia, skin infection and UTI were summarized, the post-IDS group had 37% fewer MBs (p<0.05) resulting in MB cost reductions of 34% (p<0.05). There were no significant differences in expenditures for AB and CI and in the average length of antibiotic therapy. CONCLUSION: This study shows that continuous consultation by an IDS does not increase diagnostic and treatment costs, but results in significant cost reductions.

Aged↗
PubMedDate not supplied

Missing annual external radiation dosimetry data among Hanford workers.

Epidemiological studies of workers employed at the Hanford Site have been underway for nearly 30 years. Although the external radiation dosimetry program at Hanford has been fairly comprehensive, some workers included in previous epidemiological analyses have periods of employment during which there are missing annual external radiation dosimetry records. In this report, employment history records and annual external dosimetry records have been used to investigate the extent of missing annual external dosimetry records for workers at the Hanford facility. A "nearby" procedure for estimating values for missing annual external dosimetry records was evaluated. Among the 33,459 workers who were employed at least 180 days and had at least one annual external dosimetry record, annual external dosimetry records were missing for 8% of the years of employment (32,323 missing annual external dosimetry records). Missing annual external dosimetry records were more common for female Hanford workers than for male workers, and for workers employed in the early years of Hanford's operation than for workers employed in later years of operation. The nearby procedure provided reliable estimates of values for missing annual external dosimetry records. Using this procedure, 18,937.5 mSv were estimated for missing annual external dosimetry records; this was 2% of the total recorded cumulative external radiation dose for these workers. Missing annual external dosimetry records should be considered as a potential source of bias and uncertainty in investigations of radiation-cancer associations among Hanford workers.

Air Pollution, Radioactive↗
PubMedDate not supplied

Evaluation of annual external radiation doses at values near minimum detection levels of dosimeters at the Hanford nuclear facility.

In epidemiological studies of workers exposed to ionizing radiation, recognition of the limitations of available radiation dosimetry data is important to interpretation of a study's findings. This paper provides an investigation of external radiation dosimetry data for workers at the Hanford nuclear facility, focusing on changes over time in practices for recording dosimetry measurements that were between zero and the minimum detectable level of a radiation dosimeter. Reported annual external radiation doses for the years 1944-1989 were examined for 33,459 workers; these records are the sum of periodic dosimetry measurements within a calendar year. For each year, the proportion of annual external doses with values in the range of minimum detectable level was examined. Contrary to previous researchers, we conclude that there is evidence that dosimetry measurements with values between zero and the minimum detectable level may have been recorded as zero in some historical periods. This conclusion is supported by evidence drawn from historical documentation about radiation dosimetry practices at the Hanford facility. Although workers at the Hanford facility have relatively complete and detailed external radiation dosimetry data compared to some other nuclear facilities that began operation in the 1940s, these data may suffer limitations related to dosimetry recording practices at the facility.

Adult↗
PubMedDate not supplied

[Fluorescence angiography of the anterior eye segment in severe eye chemical burns].

BACKGROUND: Severe eye burns usually result in extensive necrosis of the conjunctiva and subconjunctival tissue. To reduce the reactive inflammatory response excision of the necrotic tissue is necessary. PATIENTS AND METHOD: Between August 1990 and December 1994 fluorescein angiograms of the anterior eye segment were performed in 13 (17 eyes) patients with most severe eye burns. The angiographies were carried out 1-4 days after the accident. Conventional photo angiography was performed using a fundus camera (NF 505-AF Nikon). RESULTS: The angiograms revealed characteristic patterns that provided exact information on the perfusion of burned conjunctival and underlying tissue. It was particularly useful in the detection of clinically not recognisable subconjunctival ischemia. In addition, perfusion of the episcleral vessels and the extent of scleral ischemia could be quantified. According to the angiographic findings subtile excision of the necrotic tissue was performed and vascularized tissue was preserved. CONCLUSION: Anterior segment angiography is a valuable method in assessing the extent of necrosis of the conjunctiva and underlying tissue and in determining scleral ischemia. It provides a basis for deciding the extent of surgical debridement of necrotic tissue in the acute phase of the burn. The quantification of limbal and scleral ischemia may give useful information for early plastic-reconstructive procedures.

Adult↗
PubMedDate not supplied

[Digital fluorescein angiography in follow-up of the clinical course in therapy of patients with central vein occlusion and cystoid macular edema].

BACKGROUND: Fluorescein angiography with a scanning laser ophthalmoscope allows the quantification of morphologic and dynamic changes in the retina. In two patients with central retinal vein occlusion we monitored the progression of the cystoid macular edema (CME) and changes of microcirculation with a follow up of 4 to 6 months. MATERIALS AND METHODS: Two patients with central retinal vein occlusion and CME were examined by means of digital fluorescein angiography. Arteriovenous passage times and macular capillary blood velocities in combination with quantifications of the macular angioarchitecture and the extent of the CME were evaluated. RESULTS: Hemodilution therapy improved retinal circulation, whereas macular circulation and the severity of the CME remained unchanged. With persisting CME oral acetazolamid therapy was initiated. Oral Acetazolamide led to resorption of the cystoid edema in tandem with improved macular circulation. The capillary density was altered but remained unchanged over time. CONCLUSIONS: By means of digital analysis of fluorescein angiograms a detailed monitoring and retinal and macular dynamics, macular morphology is possible. In these two cases CME improved after Acetazolamide and moreover retinal circulation returned to normal conditions.

Acetazolamide↗
PubMedDate not supplied

A multicenter review of toxic epidermal necrolysis treated in U.S. burn centers at the end of the twentieth century.

Toxic epidermal necrolysis (TEN) is a potentially fatal disorder that involves large areas of skin desquamation. Patients with TEN are often referred to burn centers for expert wound management and comprehensive care. The purpose of this study was to define the presenting characteristics and treatment of TEN before and after admission to regional burn centers and to evaluate the efficacy of burn center treatment for this disorder. A retrospective multicenter chart review was completed for patients admitted with TEN to 15 burn centers from 1995 to 2000. Charts were reviewed for patient characteristics, non-burn hospital and burn center treatment, and outcome. A total of 199 patients were admitted. Patients had a mean age of 47 years, mean 67.7% total body surface area skin slough, and mean Acute Physiology and Chronic Health Evaluation (APACHE II) score of 10. Sixty-four patients died, for a mortality rate of 32%. Mortality increased to 51% for patients transferred to a burn center more than one week after onset of disease. Burn centers and non-burn hospitals differed in their use of enteral nutrition (70 vs 12%, respectively, P < 0.05), prophylactic antibiotics (22 vs 37.9%, P < 0.05), corticosteroid use (22 vs 51%, P < 0.05), and wound management. Age, body surface area involvement, APACHE II score, complications, and parenteral nutrition before transfer correlated with increased mortality. The treatment of TEN differs markedly between burn centers and non-burn centers. Early transport to a burn unit is warranted to improve patient outcome.

APACHE↗
PubMedDate not supplied

Responses of the QT interval of the electrocardiogram during emotional stress.

The relationship of emotional stress to the duration of the QT interval of the electrocardiogram (which contains the period of repolarization of the myocardium) was explored because QT prolongation has been shown under some circumstances to carry a risk of potentially fatal cardiac arrhythmia. A thoroughly studied case of repeated serious and ultimately fatal arrhythmia which occurred in a setting of overwhelming family and personal stress and which was preceded by marked prolongation of the QT interval prompted an experimental study of the behavior of the QT interval during stressful interviews. The subjects were 17 men and women ranging in age from 26 to 74. The experimental sessions included: 1) a period of inactivity with the subject sitting alone, 2) a period of "neutral" discussion, 3) a period of dwelling on a presumed stressful topic, followed by 4) a period of reassurance. Heart rate, respiration, arterial pressure, and the electrocardiogram were recorded throughout the four intervals together with a real time tracing of the QT interval of the electrocardiogram made by a computerized instrument recently devised by one of us (J.E.). Most of the subjects reacted to the stressful discussion with anger and resentment that was associated with shortening of QT. Two of them, however, who reacted with dejection and a feeling of being overwhelmed, displayed lengthening of QT. The QT changes were generally not linked to changes in heart rate.

Adult↗
PubMedDate not supplied

Levocabastine eye drops do not affect accommodative capacity in volunteers and intraocular pressure in glaucoma patients.

Levocabastine is a potent and highly selective H1-receptor antagonist specifically developed for the topical treatment of allergic conjunctivitis. This study assessed the effects of levocabastine eye drops on accommodative capacity in 20 healthy volunteers and on parameters influencing glaucoma in 12 glaucoma patients. A single dose of levocabastine (0.5 mg/ml) did not influence accommodative capacity, pupil diameter, or intraocular pressure (IOP) in volunteers. Similarly, levocabastine (0.5 mg/ml, one drop in each eye twice daily) for two weeks was well tolerated by patients with glaucoma. Measurement of IOP, iridocorneal angle, depth of the anterior chamber, visual acuity and near-point in these patients provided no evidence of exacerbation of glaucoma or interactions with concurrent antiglaucoma medication. Application site reactions (local irritation and ocular pain) were the only adverse effects, with an incidence comparable to placebo-treated controls. In conclusion, ocular levocabastine appears to be well tolerated, with no apparent effects on accommodative capacity or glaucoma.

Accommodation, Ocular↗
PubMedDate not supplied

Xanthogranuloma of the Erdheim-Chester type within the sellar region: case report.

Manifestations of Erdheim-Chester disease in the central nervous system are very rare. Cases with localization in the retroorbital space, hypothalamic area and posterior pituitary as well as intracerebral lesions are known. In our neurosurgical unit, a 51-year-old male patient with a history of hypophyseal insufficiency and visual deficits underwent surgery for a pituitary lesion. Histological and immunohistochemical examination revealed a xanthogranulomatous lesion composed of very large CD68-positive foam cells with small nuclei and some Touton-like giant cells, histiocytes, as well as loci with small lymphocytes and isolated eosinophilic granuolcytes, embedded in fibrotic tissue. Based on these findings, the histological diagnosis was a xanthogranuloma of the Erdheim-Chester type.

Granuloma↗