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Biomedical subjects

R Kaplan

Publications and source records attributed to R Kaplan.

At least 127 records · Page 7Linked to original sources
PubMed1987

Carbon monoxide toxicity: MR imaging in the brain.

Two cases of magnetic resonance (MR) imaging of intracranial abnormalities resulting from carbon monoxide toxicity are presented. Both cases demonstrate lesions in the globus pallidi of high MR signal intensity that correspond to previously reported abnormalities; the second case illustrates bilateral cortical high signal intensity lesions. The superiority of MR imaging in comparison with computed tomography is demonstrated in one case. The known effects of carbon monoxide toxicity in the brain are correlated with the findings of MR imaging.

Adult↗
PubMed1987

Can calcium antagonists affect the hemostatic mechanism and promote rebleeding? An experimental study.

Calcium antagonists are currently under investigation as potential beneficial drugs in the prevention of cerebral vasospasm. However, some calcium antagonists have the propensity to inhibit platelet aggregation. This study investigated the danger posed by the administration of calcium antagonists for recurrent hemorrhage in a simulated rat model of subarachnoid hemorrhage. We found that verapamil, a calcium antagonist with antiplatelet activity, lowers clot resistance and may promote rebleeding.

Animals↗
PubMed1986

Monocyte-derived growth factors for human tumor clonogenic cells.

Human peripheral blood monocytes secrete a soluble factor that enhances the ability of human epithelial tumor cell lines to clone in soft agar. Monocytes increased colony growth in a concentration-dependent manner, although inhibition of cell growth was observed in the presence of high concentrations of monocytes. Addition of indomethacin to monocytes did not abrogate this inhibition. Exposure of monocytes to endotoxin increased their ability to secrete stimulatory factors. Nonadherent lymphocytes were unable to support colony growth. Conditioned media from unstimulated monocytes also increased colony growth. Growth-promoting activity was detected in the media within the first 24 hr of culture, reaching a peak at 72 hr. Activity was not observed in monocyte lysates. Monocytes released this activity when cultured in the presence of both serum-free and serum-containing media. The activity was nondialyzable, relatively heat stable, and failed to adhere to CM-Sephadex. The demonstration of a monocyte-derived factor that enhances growth of epithelial tumor colonies supports findings indicating that inflammatory products may enhance tumor cell growth in vitro.

Adenocarcinoma↗
PubMed1986

Mononuclear phagocytes secrete a protein that directly resorbs devitalized bone particles.

The radiolabelled bone particle assay was used as an in vitro model of bone resorption. Normal human peripheral blood monocytes and the monoblastic cell line, U937, increased 45Ca release from the devitalized bone particles. In contrast, normal human peripheral blood neutrophils, resting or stimulated, did not increase 45Ca release. Exposure of monocytes to gamma interferon (INF-gamma) stimulated secretion of hydrogen peroxide and inhibited 45Ca release from bone particles. U937 cells incubated with 1,25(OH)2D3 and lymphokines had increased secretion of oxygen reduction products and increased 45Ca release. Medium conditioned by incubation with U937 cells stimulated 45Ca release to the same extent as the U937 cells. The 45Ca releasing activity in the medium was resistant to extremes of temperature and acidification. This activity is not dependent on the presence of disulfide bonds and was not inhibited by collagenase or trypsin inhibitors. Exposure to a proteolytic agent reduced the activity by over 50%. These findings are consistent with the concept that mononuclear phagocytes secrete a substance, presumably a protein, which acts directly on the bone particles. The isolation and identification of this substance may increase our understanding of the mechanisms of bone loss associated with inflammatory processes.

Bone Resorption↗
PubMed1985

Mediator release in local heat urticaria: protection with combined H1 and H2 antagonists.

Two patients with local heat urticaria were examined for evidence of histamine release and for changes in mast cell morphology after local heat challenge. Both patients demonstrated significant release of histamine into the draining venous blood in the challenged arm. Biopsy specimens revealed mucosal edema after 30 min, followed by a mononuclear, perivascular infiltrate by 6 hr, and increasing in intensity by 24 hr. Degranulated mast cells were observed by electron microscopy. Heat challenge was repeated after treatment with hydroxyzine, cimetidine, or a combination of both drugs. Neither hydroxyzine nor cimetidine alone affected the clinical response to challenge, but both drugs together completely abolished the clinical response. In addition, the combination of both drugs taken regularly completely prevented symptoms. This observation suggests that histamine is one of the major mediators of this disorder and that both H1 and H2 receptors are operative.

Adult↗
PubMed1985

Influence of mask design on bag-mask ventilation.

Adequate positive pressure ventilation in the field or emergency department continues to represent a major challenge. A new face mask design that recently has been introduced consists of a low-pressure "balloon" through which a Guedel airway is attached and extended proximally through the mask to allow the attachment of a ventilation bag. The mask is designed to seal the nares and mouth when pressed against the face. Ventilation is achieved through the airway which extends through the mask to just above the epiglottis. We designed a study to evaluate ventilating volumes and mask leak with this mask design, and to compare these parameters with those achieved with standard masks. Thirty volunteers with varied experience in bag-mask ventilation were chosen to ventilate a specially adapted ventilation manikin connected to a test lung that was capable of simulating varied compliances. Spirometers measured volumes delivered to the ventilating bag and lung, and mask leak could be calculated from these readings. A constant rate of 12 ventilations per minute was maintained by each volunteer for two minutes. Volunteers ventilated the test lung using three masks in random sequence: the SealEasy mask (Respironics Inc, Monroeville, PA), a Laerdal mask (old type), and a transparent Robertshaw mask with inflatable black rim. The average tidal volume delivered by the SealEasy mask was consistently higher than either of the other two. Significantly (P less than .05) higher volumes were delivered with the SealEasy mask when compared to the Laerdal, and significantly lower mask leaks were seen when the SealEasy was compared to both.(ABSTRACT TRUNCATED AT 250 WORDS)

Equipment Design↗
PubMed1985

Further data on the effects of subliminal symbiotic stimulation on schizophrenics.

This investigation further examined the effects of activating unconscious symbiotic fantasies in schizophrenics. One hundred twenty-eight hospitalized schizophrenic men who qualified as "relatively differentiated" on the Adjective Rating Scale were randomly assigned to four groups. Each group was assessed for pathological thinking, pathological nonverbal behavior, and self-esteem before and after the subliminal exposure of an experimental and control stimulus. The control stimulus for all groups was the message PEOPLE ARE WALKING and the experimental stimuli were the messages MOMMY AND I ARE ONE, MOMMY IS ALWAYS WITH ME, MOMMY FEEDS ME WELL, and I CANNOT HURT MOMMY (one for each group). One half of each group was subliminally exposed to verbal messages only and one half to verbal messages accompanied by congruent pictures. The first stimulus (MOMMY AND I ARE ONE) was intended to activate unconscious symbiotic fantasies that in a number of prior studies reduced pathology in groups of relatively differentiated schizophrenics. The other stimuli were intended to activate reassuring unconscious fantasies about "mommy" that were not specifically symbiosis-related. Only the MOMMY AND I ARE ONE stimulus led to more adaptive behavior and did so on all three dependent variables. This supported the supposition, also borne out in two other studies, that it is specifically symbiosis-related gratifications that are ameliorative for schizophrenics. The above results were considerably stronger for the subgroup that was exposed to a picture accompanying the MOMMY AND I ARE ONE message. This was viewed as probably the result of the pictorial representation serving as a concretization of the more abstract verbal message and as such being more relevant to the relatively primitive mode of thinking in schizophrenia.

Adolescent↗
PubMed1984

Substantive and methodological issues in a rating of cognitive and psychological function in multiple sclerosis.

There is a need for a practical, reliable, and valid rating scale for cognitive function in Multiple Sclerosis due to the high frequency of cognitive dysfunction and its consequences for patients and family. The process of rating cognitive function is examined from the point of view of the observer, the observed, and the examination and rating scales. It is concluded that observers can be trained to reduce bias and increase reliability. The patient may be a source of information through diaries, check lists, and interviews. Rating items must be based on the major cognitive deficit factors in multiple sclerosis. Standardized examination must be the basis for ratings. Rating items must be clear and closely tied to observable behaviour. A series of steps for a project to develop an acceptable international cognitive rating scale is proposed.

Cognition Disorders↗
PubMed1984

Localized cicatricial pemphigoid (Brunsting-Perry). A transplantation experiment.

Normal skin was transplanted into a cicatricial plaque in a patient affected with localized, benign pemphigoid of the Brunsting-Perry type. Eight weeks later, the transplanted tissue was removed and found to have IgG at the basement membrane zone on immunofluorescence microscopy. Subepidermal bullae developed at the graft-donor site. Local factors and trauma may be important in the pathogenesis of this variant of cicatricial pemphigoid.

Administration, Oral↗
PubMed1984

Establishment of cell lines from somatic cell hybrids between human monocytes and mouse myeloma cells.

To study human monocyte functions, we attempted to immortalize human monocytes by producing somatic cell hybrids between such monocytes and the mouse myeloma cell line NSI. In this study we report the successful establishment of eight hybrid cell lines that have been grown in culture for more than a year, and some of them retained part of the human chromosome complement, as well as monocyte markers and activities. Karyotype analysis of these hybrid lines revealed that cells of seven out of eight of the lines contained one to 16 human chromosomes and in four of them, more than nine human chromosomes were observed. Several of the cell lines expressed monocytic markers and functions. Thus, in two of the hybrid lines nonspecific esterase could be demonstrated in 10 to 29% of the cells, and Fc receptors were demonstrated in three of the hybrid cell lines. Significant levels of human ferritin were detected in one of the lines, and two other cell lines secreted interleukin 1-like substance into the culture medium. These results encourage us to use human-mouse somatic cell hybridization as an approach for the establishment of human monocyte cell lines, which will preserve their functions and produce monocyte-derived factors.

Animals↗
PubMed1983

Radiation therapy in bulky seminoma.

Between 1969 and 1980, 17 patients with bulky retroperitoneal seminoma and 1 patient with bulky mediastinal seminoma were treated with radiation therapy. One patient had resection of gross retroperitoneal disease, and 1 patient had resection of gross mediastinal disease. Fifteen patients received adjuvant irradiation to the mediastinum and paraclavicular lymph nodes, and 1 patient received adjuvant chemotherapy. At last follow-up, 17 of 18 patients (94%) remain free of disease. No patient has sustained treatment-related morbidity or mortality.

Dysgerminoma↗
PubMed1983

Successful management of severe paraquat poisoning.

A case of paraquat poisoning was successfully treated which would have been considered lethal according to a reported prognostic index. Main features in the treatment were removal of paraquat by gastric lavage, forced diuresis, hemodialysis, and charcoal hemoperfusion. Early ventilation with low FIo2 and with positive end-expiratory pressure (PEEP) were also utilized.

Charcoal↗