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J Polasek

Publications and source records attributed to J Polasek.

26 records · Page 2Linked to original sources
PubMed1993

[Fulminant pulmonary embolism in the 35th gestational week. Sonographic detection of a thrombus in the inferior vena cava with normal cavography].

Pulmonary embolism is the most common cause of maternal death during pregnancy. CASE REPORT. We report a 28-year-old obstetric patient (35th gestational week) who was admitted to the hospital because of intermittent vaginal bleeding caused by placenta totalis et accreta. Eleven days after admission she suffered a cardiac arrest. After cardiopulmonary resuscitation, an emergency caesarian section was performed and a healthy child was delivered. Abdominal sonography (B-mode) showed a floating thrombus in the inferior vena cava. Perfusion scintigraphy and cavography were normal; a computed tomography i.v. contrast medium study confirmed the presence of the thrombus. An open thrombectomy was performed to protect the patient from further pulmonary emboli. After 8 days she left the intensive care unit without residual complications. CONCLUSION. This case emphasises the importance of bedside sonography as a diagnostic method of identifying the source of a thrombus in patients with suspected pulmonary embolism.

Adult↗
PubMed1992

Innovative desktop learning tools. Implications for rural hospitals and physicians.

Innovative methods of providing workplace education for health care professionals may be a key to the survival of rural hospitals in America. Such methods must overcome time, distance, cost and organizational constraints, and take into account the structure of the learning experience. The Texas Hospital Education and Research Foundation has recently been involved in two programs that tested new approaches to worker education using distance-learning strategies. The projects--resource sharing among rural directors of nursing and training for cancer tumor registrars--used computer-conferencing technology. A new model using existing satellite, audio-conferencing, and computer-based instruction augmented by computer conferencing is proposed. The Computer-Related Assisted Distance Learning Enhancement (CRADLE) model integrates existing technologies to provide education to health care workers at their desktop. The Cancer Learning Center (CLC) tested peer collaboration, the primary component of the model. The ultimate goal is to have the system available to all tumor registrars in Texas, and to secure funding to implement rural nursing and rural high-school health occupations education projects. Current projects from set-up through results are presented.

Computer Communication Networks↗
PubMed1989

Lysosomal concept of platelet secretion--revisited.

Certain morphological and biochemical aspects of platelet secretion are discussed. Based on own experiments and review of the literature a hypothesis is forwarded that platelet secretory granules or rather storage organelles can be viewed as secondary lysosomes participating in platelet endocytosis and exocytosis. Formation of the platelet thromboplastic activity, so called PF3, is linked to the platelet storage organelles disintegration and lypolysis during their exocytosis through the platelet plasma membrane.

Adenosine Diphosphate↗
PubMed1987

Evidence for an alternative mechanism of human platelet secretion involving peripheralization of secretory granules and formation of membrane-associated multivesicular structures.

Stimulated platelets release the content of their granules to the environment by a process known as platelet secretion. The precise mechanism of platelet secretion is poorly understood. The most widely-held theory suggests that, during platelet activation, secretory granules centralize and their content is released into the surface-connected canalicular system. Using fixation techniques directed at preserving membrane structures, morphological evidence is provided that human platelet activation is associated with secretory granules migrating to the periphery of platelets, where they undergo transition to participate in the formation of membrane-associated multivesicular structures. These multivesicular structures then undergo dissolution resulting in granule content secretion to the environment. The formation of the membrane-associated multivesicular structures occurs in platelets in which some of the secretory granules have also become centralized. This suggests that during the activation of human platelets, membrane-associated multivesicular structure release may occur concurrently with other mechanisms of secretory granule content release. The present observations are consistent, however, with the hypothesis that during human platelet activation the formation of membrane-associated multivesicular structures by platelet secretory granules contributes importantly to the mechanism of platelet secretion.

Blood Platelets↗
PubMed1984

Release of multivesicular bodies from platelets as observed in SEM.

Scanning EM was used to study platelet shape changes induced by collagen in citrated PRP. While using a modified fixation technique known to protect phospholipids from extraction during alcohol dehydration a release of multivesicular bodies from platelets was observed. Maximum frequency of their appearance correlated with the onset of a release reaction from platelets as seen in an aggregometer curve. Depicted structures may thus be related to the release of different platelet constituents.

Blood Platelets↗