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Biomedical subjects

A Kiss

Publications and source records attributed to A Kiss.

At least 181 records · Page 10Linked to original sources
PubMed1993

Regulation of the hypothalamic pituitary adrenal axis during chronic stress: responses to repeated intraperitoneal hypertonic saline injection.

Chronic osmotic stress inhibits, while repeated physical stress can increase pituitary ACTH responsiveness to a novel stress. The interaction between these effects was studied in rats subjected to repeated i.p. injection of hypertonic saline, a strong aversive stimulus with osmotic and painful and psychological stress components, for 14 days. Hypertonic saline injection caused marked drinking responses, transient increases in plasma vasopressin (VP), and marked increases in VP mRNA and irVP in magnocellular cell bodies in the hypothalamus. Parvicellular activity was also enhanced as indicated by increases in VP immunostaining in the external zone of the median eminence and CRH mRNA and irCRH in the PVN. Plasma ACTH levels increased 10-fold after 30 min hypertonic saline injection, returning to basal levels in 4 h, and there was no desensitization of the ACTH responses after repeated injections (from basal values of 76 +/- 10 to 782 +/- 57, 788 +/- 83 and 779 +/- 31 pg/ml 30 min after the first, 4th and 14th injection, respectively). Basal ACTH levels were normal 24 h after the last injection, but pituitary POMC mRNA levels were increased by 95%, and ACTH responses to a novel stress (15 min immobilization) were significantly larger than in controls (P < 0.01) despite increases in morning plasma corticosterone levels (1.5 +/- 0.4 and 9.2 +/- 3.1 micrograms/dl in controls and stressed rats, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1993

[Congenital absence of the left pericardium. Case report and review of the literature].

Congenital absence of the pericardium, whether partial or total, is a rare abnormality. If suspicion of such a malformation arises it should be classified because of possible herniation of the atrium or ventricle. The authors report the case of an asymptomatic young male patient in whom the diagnosis was suggested radiographically, electrocardiographically (total electrical alternans has been noticed) and confirmed by cross-sectional echocardiography, computed tomography and magnetic resonance imaging. Only in exceptional cases should it be necessary to perform an exploratory thoracotomy. In patients with complete pericardial defects no specific therapy is indicated, however, in patients with partial defects surgical treatment is indicated. Congenital pericardial defects are not completely benign, as has been suggested before.

Adult↗
PubMed1993

[A bleeding jejunal schwannoma. The complications of a rare neoplasm of the small intestine].

The authors report a rare case of jejunal Schwannoma which appeared as hematemesis and melaena. No preoperative test, even selective angiography, enabled a correct clinical diagnosis to be made. Only after explorative laparotomy and careful palpation of the small intestine was the bleeding lesion located. Resection and termino-terminal anastomosis were then performed. The preparation of immunohistochemical reactions now allow forms which were previously diagnosed in different terms to be precisely classified.

Adult↗
PubMed1993

Antiretroviral immune response and plasma interferon in different phases of chronic granulocytic leukemia.

Forty patients with chronic granulocytic leukemia (CGL) were tested for antibodies and lymphocytes reacting with gibbon ape leukemia virus (GaLV) and baboon endogenous virus (BaEV) antigens as well as for plasma interferon levels. Antibodies reacting with envelope antigens of GaLV and BaEV were found frequently and in high titers in patients with the quiescent phase of CGL but rarely and in low titers in the accelerated and blastic phase of the disease. Results of radioimmunoprecipitation studies were in concordance with those obtained in virus neutralization experiments. Cellular and humoral cytotoxic activity of blood plasma and lymphocyte samples against autologous tumor cells showed a similar phase-specific distribution. Most of these activities could be blocked by GaLV and BaEV gp70 antigens. Elevated plasma interferon (IFN)-alpha levels were found in the quiescent and accelerated phase of CGL, whereas no significant differences could be detected between IFN levels of patients with the blastic crisis of CGL and those of the control persons. Follow up studies of four patients confirmed this stage-specific distribution of antiretroviral immune and interferon response.

Animals↗
PubMed1993

Studies on acute myelomonocytic leukemia in LBF1 rats.

Granulocytic leukemia was induced in Long-Evans (LE) rats by using the Huggins and Sugiyama method. After serial passage the cells became transformed. The newly transformed cells could be transplanted to LBF1 hybrid rats and observed more readily. A quantity of 10(8) cells/100 g body weight was injected intravenously and after 2-3 weeks myelomonocytic leukemia developed. By examining the bone marrow, spleen and lymph nodes, cytochemical tests verified this transformation. Transplanting 10(2)-10(4) cells under the renal capsule, a quickly growing solid tumor was observed, which caused metastasis to the parathymical lymph nodes and peritoneum. The investigation of oncogene expression for the myc and ras families revealed the presence of myc p62 and ras p21 oncoproteins in the tumor cells by using monoclonal antibodies in immunohistochemical tests. LBF1 rats proved to be good models in obtaining solid tumor growth and myelomonocytic leukemias, equivalent to human M4-M5 type leukemia.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

Megakaryocyte markers in myeloproliferative disorders.

Identification of megakaryocyte precursors with immunohistochemical methods in bone marrow trephine biopsy specimens (embedded in a plastic resin, Immuno-Bed) was performed from patients with blastic phase of chronic granulocytic leukaemia (five cases), from chronic megakaryocytic-granulocytic myelosis (four cases) and from acute megakaryoblastic leukaemia (11 cases). In megakaryoblasts of bone marrow biopsies immunohistochemical reactions using the ABC method and monoclonal antibodies against von Willebrand antigen and GpIIb/IIIa (CD41) were visible in various percentages depending on the maturation's degree of megakaryocyte precursors. The number of circulating blast cells determined by flow cytophotometry was nearly similar to those of observed in biopsies. The greatest bone marrow reticulin content could be detected in acute megakaryoblastic leukaemia cases. Despite the different clinicopathological entities, the presence of the same phenotype (megakaryoblasts) was associated with a short survival in these haematological malignancies (in CGL MKB phase 4.0, in CMGM MKB phase 4.2, and in AML M7 5.8 months, respectively).

Adult↗
PubMed1993

Activation of magnocellular vasopressin responses to non-osmotic stress after chronic adrenal demedullation in rats.

Increases in plasma VP in response to osmotic stimulation are critical for water conservation, while VP released into the pituitary portal circulation is an important regulator of ACTH secretion and does not contribute to plasma VP levels. The role of the adrenal medulla in the specificity of these responses was studied in rats subjected to osmotic and non-osmotic stress two months following adrenal demedullation or sham operation. Basal and stimulated plasma corticosterone, aldosterone, ACTH and PRA levels in adrenal demedullated rats were similar to those in the sham operated groups indicating recovery of adrenocortical function. Basal plasma VP level were similar in sham operated controls and adrenal demedullated rats (0.93 +/- 0.13 and 1.0 +/- 0.1 pg/ml, respectively) and rose to comparable levels in both groups following 48 h osmotic stimulation by water deprivation (14.4 +/- 1.3 and 20.7 +/- 3.4, respectively). On the other hand, while in sham operated rats, immobilization for 15 min, a non-osmotic stress, had no effect on plasma VP levels in control or water deprived (2.0 +/- 0.9 and 15.0 +/- 2.7 pg/ml), in adrenal demedullated rats, caused dramatic increases in plasma VP from 1.0+/-0.1 to 126.0+/029.9 pg/ml in controls, and from 20.7 +/- 3.4 to 155 +/- 37 pg/ml in water deprived rats. Intraperitoneal hypertonic saline injection, a combination of osmotic and painful stress, caused much higher increases in plasma VP in adrenal demedullated rats (138.0 +/- 22.1 compared with 34.7 +/- 3.7 pg/ml in sham operated rats). Water deprivation potentiated this response to 70.0 +/- 8.3 and 295 +/- 24 pg/ml in sham operated and adrenal demedullated rats, respectively. VP mRNA measured by in situ hybridization, and irVP measured by immunohistochemistry, were elevated in magnocellular neurones in the hypothalamus of adrenal demedullated rats. The demonstration of marked plasma VP responses to non-osmotic stimuli in adrenal demedullated rats, suggests a modulatory role for the adrenal medulla in the specificity of the secretory responses of the magnocellular and parvicellular vasopressinergic systems.

Adrenal Medulla↗
PubMed1993

Contrasting effects of central alpha-1-adrenoreceptor activation on stress-responsive and stress-nonresponsive subpopulations of corticotropin-releasing hormone neurosecretory cells in the rat.

Stimulation of the rat hypothalamopituitary-adrenal axis during stress involves activation of central alpha 1-adrenergic receptors. The subpopulation of corticotropin-releasing hormone (CRH) neurosecretory cells that contains vasopressin (VP) is selectively activated by several types of stress (immobilization, hypoglycemia, and intracerebroventricular, i.c.v., colchicine), and is located in a catecholamine-rich area of the hypothalamic paraventricular nucleus. Therefore, we tested the hypothesis that the CRH+/VP+ subpopulation is selectively activated by central alpha 1-adrenergic receptors. The alpha 1-agonist methoxamine or vehicle alone was injected i.c.v. after habituation of rats to daily injections of vehicle through a chronic i.c.v. cannula. Activation of the CRH+/VP+ and CRH+/VP- subpopulations was measured by quantifying depletion of neurosecretory vesicles from immunocytochemically identified axons in the external zone of the median eminence. The habituated, vehicle-injected sham control group had normal levels of plasma ACTH and corticosterone, but possessed a significantly higher proportion of VP-containing CRH axons than naive animals. This change is similar to what was observed previously in rats subjected to repeated daily stress. I.c.v. methoxamine caused elevations of plasma ACTH and corticosterone and significant depletions of vesicles from the CRH+/VP+ axons at 1 and 2 h after injection, compared to the sham control group. The CRH+/VP- axons, however, displayed significant accumulations of neurosecretory vesicles at the same times after 300 micrograms methoxamine, compared to the sham control group. After 100 micrograms methoxamine, there was no change in the CRH+/VP- axons, compared to the sham control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1993

Regulation of the hypothalamic-pituitary-adrenal axis during water deprivation.

The contribution of the magnocellular vasopressinergic system to the regulation of ACTH secretion was studied by analysis of hypothalamic-adrenal axis function in rats subjected to water deprivation for 48 h. Water deprivation resulted in marked increases in plasma osmolarity and vasopressin (VP) levels and hypothalamic VP mRNA and immunoreactive (ir) VP in magnocellular neurons. While CRH mRNA levels in the paraventricular nucleus were decreased, irCRH accumulation in paraventricular nucleus neurons after colchicine treatment was normal or increased. Similarly, the irCRH content in the median eminence and its release under stress were similar in control and water-deprived rats. While basal plasma ACTH levels were similar in both groups (34.5 +/- 3.8 and 39.8 +/- 3.3 pg/ml), levels stimulated by CRH injection (10 micrograms, i.v.) or 15-min immobilization stress were reduced by 47% (P < 0.01) and 43% (P < 0.05), respectively, in water-restricted rats. The decreased ACTH responses were not prevented by injection of CRH (7.5 micrograms/day, sc) during the period of water deprivation. In contrast to the ACTH responses, basal and CRH-stimulated plasma corticosterone levels were significantly elevated (P < 0.001), and the responses to acute stress were normal. The inhibition of ACTH secretion was not due to increased glucocorticoid feedback, since similar blunted ACTH responses to acute immobilization stress were observed in adrenalectomized rats receiving corticosterone replacement. Despite similar levels of pituitary POMC mRNA, pituitary ACTH content was reduced in water-deprived rats, suggesting a posttranscriptional inhibition of POMC synthesis or processing. The data demonstrate that osmotic activation of the magnocellular VP system is accompanied by reduced responsiveness of the corticotrophs, an effect that is not due to increased glucocorticoid feedback or hypothalamic CRH deficiency. These findings suggest that the magnocellular vasopressinergic system does not play an important role in the regulation of ACTH secretion during chronic osmotic stimulation.

Adrenal Glands↗
PubMed1992

Purification and biochemical characterization of the EcaI DNA methyltransferase.

The EcaI GGTNACC-specific DNA-adenine modification methyltransferase has been purified to apparent homogeneity. The active form of the DNA methyltransferase is a single polypeptide. The enzyme has a pH optimum at pH 8.0 and a temperature optimum at 25 degrees C. EcaI DNA methyltransferase transfers one methyl group to the adenine of the recognition site in a single binding event. The Km was 170 nM for DNA and 1.8 microM for the methyl donor S-adenosylmethionine. Methylated DNA is a competitive inhibitor with respect to DNA (Ki = 3.5 nM). The other product of the DNA-methylation reaction, S-adenosylhomocysteine was found to be a competitive inhibitor with respect to S-adenosylmethionine (Ki = 2.7 microM). The S-adenosylmethionine analog sinefungin was shown to be a very strong inhibitor (Ki = 3.5 nM) of the DNA methyltransferase reaction.

Adenosine↗
PubMed1992

[Secondary acute leukemia in Hodgkin's disease].

Two secondary acute leukaemias out of 166 patients with Hodgkin's disease were detected. At a young female patient treated only with chemotherapy the acute leukaemia developed 39 months following the diagnosis of Hodgkin's disease. Phenotype of leukaemic blast cells could not be determined exactly. After a short complete remission (1,5 month) the patient died because of the progression of her leukaemic process. The other young male patient treated with radio- and chemotherapy had six years disease free interval between the diagnosis of two malignant diseases. The combined cytostatic treatment of his acute lymphoblastic leukaemia resulted complete remission that lasted for one year but later the progression of leukaemia caused death. In connection with these cases the authors reviewed the current questions of treatment related acute leukaemias in Hodgkin's disease.

Adolescent↗
PubMed1992

[Patients with functional symptoms--what should be done?].

Unspecific complaints are one of the major reasons why doctors are consulted. The management of these patients is difficult and has been little explored. Most doctors confine their efforts to ruling out organic causes for the patient's symptoms, a policy which often results in frustration for both doctor and patient. The following guidelines for better management have proven useful in clinical practice: (1) Psychosocial history: Psychosocial data should be obtained from the start, not only when no organic reason is found to explain the symptoms. (2) Specific questions: What alleviates symptoms, what makes them worse? In the case of vague answers ("stress") it is preferable to check before giving hasty advice. (3) Disclosing the diagnosis: It is necessary to convey the idea that the symptoms are real. Phrases such as "It's nothing" or "It's all in your head" should be avoided. (4) Lay theory: The patient's view of the reasons for his symptoms should be explored. (5) Agreement on working hypotheses: Knowing the patient's lay theory, the doctor can shape his suggestions to match the patient's convictions. (6) Therapeutic goals: Establishment of a climate of trust between patient and doctor can avoid "doctor shopping" and protect the patient from unnecessary diagnostic procedures. (7) Psychotherapeutic techniques: A supportive approach and relaxation techniques of limited duration (5-10 consultations) afford long-term benefit.

Diagnosis↗
PubMed1992

[Doctor-patient relationship--its quality and possibilities for improvement].

A review of the last decade's literature suggests that the doctor-patient relationship could be improved in three main respects: (1) Medical, social and psychological information is obtained incompletely or incorrectly. (2) A positive emotional relationship with the doctor is reported by the patient who has been able to talk about his own ideas, fears and expectations. The doctor rarely enquires about the latter and, if he does so, pays little attention to the reply. (3) Patients are not well informed about prior test results, prognosis or etiology. Concepts in social psychology afford valuable and practical hints in improving the doctor-patient relationship: checking on what the doctor and patient have said; a structured interview (use of a list of topics; open discussion of time limits); avoidance of yes/no type questions at the beginning; perceptions of patients' emotions; partnership-based approach. As a means of approaching the doctor-patient relationship on a psychoanalytic basis, Balint groups have proved of value.

Communication↗
PubMed1992

Nucleolar organizer regions in acute and chronic leukaemias.

A silver staining technique for nucleolar organizer regions (NORs) has been applied to bone marrow biopsies of various types of acute and chronic leukaemias. This method could be easily evaluated on resin-embedded bone marrow obtained from acute lymphocytic leukaemia (n = 12), acute myelogenous (n = 16), chronic lymphocytic (n = 16) and chronic granulocytic (n = 20) leukaemia. A significant difference (p < or = 0.1) was only found between the AgNOR numbers in nuclei of lymphocytes from acute and chronic leukaemia (mean of 1.23 to 1.40 and 1.58) and those of cells from acute and chronic myelogenous leukaemia (from a mean of 5.00 to 9.17 per nucleus). However, no significant difference was observed among cells of various types of acute and chronic myelogenous leukaemias, despite of their markedly higher staining intensity and proliferative activity. The greatest mean of AgNOR numbers was counted in monoblasts of acute myelomonocytic leukaemia. It is suggested, that higher AgNOR counts in nuclei of more malignant leukaemic cells are in parallel with their mitotic activity and could be related to their elevated cell turn-over.

Bone Marrow↗
PubMed1992

Participation of alpha 1-adrenergic receptors in the secretion of hypothalamic corticotropin-releasing hormone during stress.

The role of alpha 1-adrenergic receptors in the secretion of corticotropin-releasing hormone (CRH) during stress was studied by immunohistochemical analysis of the CRH content of the median eminence (ME) after intracerebroventricular (icv) administration of the alpha 1-adrenergic agonist, methoxamine, or the antagonist, prazosin, in rats pretreated with colchicine. Immunohistochemical staining was performed by the peroxidase technique on 40 microns free-floating sections using a polyclonal antibody specific for CRH. In the first experimental model, rats were implanted with icv cannulae and adapted to the experimental conditions by daily handling and icv injection of artificial CSF. Colchicine (75 micrograms) was administered through the cannulae 6 h before the experiment, conditions in which axonal transport was blocked with little change in basal immunostaining. Two hours after immobilization stress or a single injection of methoxamine (100 micrograms, icv), there was a marked decrease in CRH immunoreactivity throughout the ME, reflecting release of the neuropeptide into the portal circulation. The decrease in CRH immunostaining following immobilization was largely prevented by icv injection of the alpha 1-adrenergic antagonist, prazosin. In the second experimental model, rats were sacrificed 48 h after icv colchicine injection, conditions in which colchicine acts as a stressor and causes marked depletion of irCRH from the ME. This chronic effect of colchicine was also partially prevented by administration of prazosin, 400-ng injection 5 min prior to colchicine, followed by a continuous icv mini-pump infusion of prazosin, indicating that alpha 1-adrenergic stimulation contributes to the action of colchicine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Demonstration of HTLV-related proviral DNA sequences and antibodies reactive with HTLV internal proteins in an Hungarian patient with Sézary syndrome.

DNA sequences distantly related to the proviral DNA of HTLV-I were found in the leukemic cells of a Hungarian patient suffering from Sézary syndrome. Serum samples from the patient contained antibodies reactive with the internal core polypeptides of HTLV-I and HTLV-II, but not with the env gene encoded type-specific HTLV antigens. The husband and daughter of the patient also had antibodies of the same specificity. These findings suggest the presence of a virus distantly related to HTLV-I and HTLV-II.

Adult↗