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Biomedical subjects

P Czerniak

Publications and source records attributed to P Czerniak.

At least 19 recordsLinked to original sources
PubMed1993

Effects of modulation of basic fibroblast growth factor on tumor growth in vivo.

BACKGROUND: Recombinant human basic fibroblast growth factor (rHu-bFGF) is known to stimulate proliferation in some tumor cells and to modulate tumor vascularization. PURPOSE: The purpose of this study was to examine the possible role of this agent in the development of tumors. The study was designed to determine the effects of modulating bFGF activity in vivo in tumor models from cell lines with different responses to bFGF and with different content and receptor levels of bFGF. METHODS: Two tumor cell lines (human DLD-2 colon carcinoma and rat C6 glioma) were characterized for bFGF content and bFGF receptor levels by Western blot analysis in cultured cells and by studies of [125I]rHu-bFGF binding to sections from xenografts grown in nude mice. Tumor cell proliferation was monitored after treatment with rHu-bFGF or the DG2 or DE6 IgG monoclonal antibody to rHu-bFGF in culture and in vivo. RESULTS: C6 cells exhibited 7800 high-affinity receptors for rHu-bFGF per cell (dissociation constant [Kd] = 46 pM), while DLD-2 cells lacked high-affinity receptors. rHu-bFGF stimulated [3H]thymidine uptake by C6 cells, but the addition of DG2 IgG prevented this stimulation; rHu-bFGF had no effect on [3H]thymidine incorporation by DLD-2 cells. C6 cells had higher levels of immunoreactive bFGF than did DLD-2 cells. The xenografts from both cell lines exhibited high-affinity [125I]rHu-bFGF binding that was concentrated on vascular-like structures. rHu-bFGF at a dosage of 0.25 mg/kg given intraperitoneally daily for 18 days caused a twofold increase in DLD-2 tumor weight but had little effect on the growth of C6 xenografts. In contrast, daily intravenous injections of DG2 IgG given to mice had no effect on DLD-2 tumor growth but reduced growth of C6 tumors by approximately 30%--a statistically significant difference. CONCLUSIONS: The addition of exogenous rHu-bFGF or of a neutralizing antibody resulted in significant alterations in tumor growth in vivo, which were specific for tumor type and bFGF characteristics. While some of these effects may be mediated by the bFGF-responsive endothelial cells of the tumor vasculature (DLD-2 colon carcinoma), others may result from inhibition of bFGF-dependent tumor cell proliferation (C6 glioma). IMPLICATIONS: Studies that measure tumor blood flow are necessary to confirm that these effects are mediated by changes in tumor vasculature.

Animals↗
PubMed1988

Treatment of osteoradionecrosis combined with pathologic fracture and osteomyelitis of the mandible with electromagnetic stimulation.

Osteoradionecrosis, complicated by pathologic fracture and osteomyelitis, is difficult to treat. Electromagnetic stimulation therapy may present a solution to this problem. A case of a 66-year old woman, suffering from osteoradionecrosis, pathologic fracture and osteomyelitis of the mandible, 6 years after irradiation therapy and partial resection of the mandible for squamous cell carcinoma of the gingiva, treated by electromagnetic stimulation, is presented. After 9 months of treatment, the patient was asymptomatic. Radiographic examination and bone scintigraphy carried out upon termination of the treatment, proved that healing of osteoradionecrosis and osteomyelitis had occurred. As far as we know, no previous reports have been published regarding this type of treatment.

Aged↗
PubMed1985

RIA examinations of CSF hormones as a method of demonstrating leakage through the blood-brain and brain-CSF barriers.

Radioimmunoassay determinations of the levels of total T3, total T4, TSH, and prolactin in the CSF were performed on samples taken from 36 healthy individuals. The obtained reference values are the first of their kind. It is considered that RIA determinations of CSF hormone levels may provide a sensitive method for demonstrating pathological leakage through the blood-brain and brain-CSF barriers.

Blood-Brain Barrier↗
PubMed1980

Direct subdural scintigraphy. Report of a case with subdural effusion following pneumococcal meningitis.

We report a case of pneumococcal meningitis in an 8 weeks olf female infant followed by persistent subdural effusion successfully treated by repeated subdural taps. The initial delineation of the subdural effusion, the decrease in size and the disappearance of the fluid were demonstrated by direct subdural scintigraphy (D.S.S.). The literature of pneumococcal meningitis, its diagnosis, treatment and complications are reviewed, and it is suggested that direct subdural scintigraphy should be employed as a diagnostic aid in the evaluation and follow up of subdural effusions.

Female↗
PubMed1978

Blood-C.S.F. barriers dysfunction in the chronic organic brain syndrome; a R.I.A. study.

C.S.F. samples of 35 patients, who suffered from verified chronic, non-tumorous organic brain syndrome, were radioimmunoassayed for T4 and T.S.H., and were compared to C.S.F.-R.I.A. samples from a control group of patients who underwent myelography because of lumbar disc. In addition T4 and T.S.H. plasma levels were evaluated in the O.B.S. patients. C.S.F. T4 and T.S.H. levels were significantly higher in 65% of the O.B.S. group of patients than those of the control group. The average determinations for T4 were: 0.77 muh/100 ml in O.B.S. group as against 0--0.4 micrograms/100 ml in the C.S.F.'s of the control group. P greater than 0,001 T.S.H. C.S.F. levels were 1.33 microU/ml in the O.B.S. group, and 0--0.6 microU/ml in the control group (P greater than 0.005). It is suggested that the elevated R.I.A. values of these hormones in the C.S.F. of the O.B.S. patients reflect a disruption of blood-C.S.F. barriers. Therefore in the organic brain syndrome there seems to exist a pathophysiological dysfunction of brain barriers in addition of the neural damage.

Adult↗
PubMed1977

Thoracoscintigraphy in the differential diagnosis of cardiomegaly.

"Thoracoscintigraphy" is a radioisotopic scanning technique for demonstrating the nature of an enlarged cardiac shadow found on chest X-ray. The technique consists of superimposing scintiscans of the cardiac blood pool, the liver and the lungs and comparing the outline of the cardiac blood pool image with the cardiac shadow seen on X-ray. With this procedure the correct diagnosis of pericardial effusion was made in 11 of 15 patients and of pure cardiac dilatation and/or myocardial hypertrophy in three patients. In one of the patients the thoracoscintigraphic diagnosis was equivocal. Thoracoscintigraphy clearly demarcates the cardiac shadow from the surrounding organs, delineates the intracardiac blood pool within the cardiac shadow and indicates the best approach for pericardiocentesis. The procedure is harmless and noninvasive, and the radiation exposure is low and safe.

Adult↗
PubMed1976

Triiodothyronine radioimmunoassay and its application to thyroid disorders.

An accurate, highly sensitive triiodothyrone (T3) radioimmunoassay system is described. Direct measurement in serum is made possible by the use of T3-free serum for standards, and blocking of T3 binding to thyroxine (T4)-binding globulin with salicylate. T4 cross reactivity was less than 0.3%. Mean T3 levels in 55 euthyroid, 32 hyperthyroid and 19 primary hypothyroid patients were 1.46 +/- 0.17, 5.34 +/- 1.86 and 0.49 +/- 0.34 (SD) ng/ml, respectively. T3 was found to be a more sensitive index than T4 in hyperthyroidism; in hypothyroidism it overlapped with euthyroidism. The presence of goiter had no effect on T3 concentrations in euthyroid patients. Among the patients studied, eight were found to have T3 toxicosis, including two patients with recurrent thyrotoxicosis. A significant T3 elevation was also found in euthyroid patients after thyroidectomy whereas T4 remained normal. The extent of T4 and T3 elevation was similar during the initial phase of subacute thyroiditis. There were significantly lower T3 values and higher thyroid-stimulating hormone values in umbilical cord blood than in maternal blood. In two euthyroid subjects, thyrotropin-releasing hormone stimulation caused a 50% rise in T3 levels and no change in T4 levels over a 2-h period.

Female↗
PubMed1975

Head and brain scan findings in rhinocerebral mucormycosis: case report.

Brain and bone scan findings in two patients suffering from rhinocerebral mucormycosis following kidney transplantation are presented. Two patients who had had kidney transplants and were sustained for over a month on immunosuppressive drugs developed a rare type of opportunistic infection--mucormycosis. They were examined in various stages of their disease. Special attention was paid to the scintillagraphic findings.

Adult↗