Regulation of purinoceptors in guinea pig pulmonary artery: functional evidences.

In isolated guinea pig pulmonary arteries (precontracted with 1 microM noradrenaline) N6-cyclopentyladenosine (CPA), a selective A1 adenosine receptor agonist, exerted a concentration-dependent contraction, whereas 5'-N-ethylcarboxamidoadenosine (NECA), a non-selective A1/A2 receptor agonist, in the presence of DPCPX (a highly selective A1 receptor antagonist), produced a concentration-related rapid relaxation. Pulmonary arteries obtained from guinea pigs treated with aminophylline (APH) or 8-phenyltheophylline (8-PT) for 10 consecutive days, displayed more pronounced contraction in response to CPA compared to those of solvent-treated animals. Relaxant action of NECA was, however, attenuated in arteries prepared from methylxanthine-treated guinea pigs.

On the cardioprotective effect of adenosine.

In isovolumically perfused Langendorff heart preparations of guinea pigs adenosine-depending on the experimental protocol-more or less could prevent the hypoxia-induced decrease in myocardial adenosine triphosphate [ATP], creatine phosphate [CP], glycogen and increase in lactate, i.e. showed cardioprotection.

Long-lasting treatment with adenosine receptor antagonists: effects on hypoxic tolerance and vascular responsiveness.

In electrically driven myocardial preparations obtained from chronically methylxanthine-[aminophylline (APH) and 8-phenyltheophylline (8-PT)] or solvent(DMSO)-treated guinea pigs no differences were found in alteration of mechanical activity under hypoxia and reoxygenation. The vasoconstrictor effects observed after in vitro exposure of pulmonary arterial preparations (excised from either methylxanthine- or solvent-treated guinea pigs) to both noradrenaline and PGF2 alpha were also similar. In methylxanthine-treated vascular tissues, however, nitroglycerin and NO exerted more pronounced vasorelaxant effect than in specimens prepared from solvent-treated guinea pigs.

Parameters of respiratory burst and arachidonic acid metabolism in polymorphonuclear granulocytes from patients with various thyroid diseases.

The oxidative processes (oxygen consumption, superoxoid anion generation, arachidonic acid cascade) of human polymorphonuclear granulocytes (PMNs) obtained from patients suffering from thyroid disorders of autoimmune origin (Graves' disease and Hashimoto's thyroiditis), and non autoimmune origin (toxic adenoma) were investigated. All Graves' and toxic adenoma patients were hyperthyroid. Hashimoto's thyroiditis patients were euthyroid.

[In vitro comparative study of instruments for root canal preparation. IV. Correlations between the original shape of the root canal and the asymmetry resulting from the preparation].

Certain asymmetry of root canal preparation can be observed in the straight root canal group, as well. The modification of original root canal shape in this group usually is not substantial. Using hand instruments for shaping curved canals special tecniques are required to minimize the asymmetry.

Bidirectional enhancing activities between human T cell leukemia-lymphoma virus type I and human cytomegalovirus in human term syncytiotrophoblast cells cultured in vitro.

The syncytiotrophoblast layer of the human placenta has an important role in limiting transplacental viral spread from mother to fetus. Human cytomegalovirus (HCMV) is capable of establishing a latent infection in syncytiotrophoblast cells, with restriction of gene expression to immediate-early and early proteins. We analyzed the extent of replication of human T cell leukemia-lymphoma virus type I (HTLV-I) in human term syncytiotrophoblasts infected with HTLV-I alone or coinfected with HTLV-I and HCMV.

A mathematically based classification of root canal curvatures on natural human teeth.

Testing of root canal-shaping instruments on natural human teeth has many difficulties, because of the different anatomical forms of root canals. There is a lack of an internationally accepted and mathematically based classification of root canal morphology. The aim of this study was to give a mathematical description of root canal forms with the help of differentiated geometrical pattern analysis and computer graphics.

Genetic abnormalities in sporadic parathyroid adenomas: loss of heterozygosity for chromosome 3q markers flanking the calcium receptor locus.

Inactivating mutations of the parathyroid cell calcium receptor (CaR) gene cause one form of familial benign/hypocalciuric hypercalcemia, and in homozygous form, cause neonatal severe primary hyperparathyroidism with parathyroid hyperplasia. Thus, we postulated that partial or total loss of CaR function might contribute to calcium insensitivity or even stimulate cell proliferation in sporadic parathyroid adenomas (PAds). To examine this possibility, we sought loss of heterozygosity (LOH) for markers flanking the CaR locus (3cen-3q21) in 35 PAds.

[In vitro comparison of instruments for root canal preparation. III. Study of the instruments from the viewpoint of shaping asymmetry].

The shape of the prepared root canals is not consistent with the original anatomical shape in the majority of curved canals. The discrepancy is dependent of the type of instrument, the original anatomical form of the root canal and the location of the measurement. The original shape of the root canal has to be taken into consideration in the selection of preparatory instruments because their application is limited by the above mentioned factor.

[Ultrasonic diagnosis of exencephaly/anencephaly during the first trimester].

The paper deals with first trimester diagnosis of exencephaly. In association with first trimester sonographic and cytogenetic screening of chromosomal anomalies in 1145 examined pregnancies 2 exencephalic fetuses with normal karyotype were diagnosed. Exencephaly was characterized with the absence of normal echoes of the exocranium, the lateral ventricles, the chorioid plexus, the cerebral falx, and with the presence of deformed shape of the head and irregular, lobulated cerebral material with increasing volume at follow-up examination.

[In vitro comparison of instruments used for root canal preparation. II. Effectiveness of the instruments].

According to our examination, the anatomical shape of the root canal can influence the function of the examined instrument, therefore it's advisable to pay attention to the canal's curve at the selection of the root canal cutting instrument. Concerning the examined instruments, the least effective was the ultrasonic instrument.

[In vitro comparison of instruments for root canal preparation. I. Pilot study of the homogeneity of study groups].

If extracted human teeth are used for comparative study of root canal preparatory instruments the selection of roots into homogeneous test groups is decisive step of the experiment. On the basis our pilot USDA it is necessary not only to consider the Schneider angle and the length of root canal curvature but the surface area of root canals on the mesio-distal and oro-vestibular radiographs showing the projected view of the canals.

Negative regulators may mediate some of the inhibitory effects of HIV-1 infected stromal cell layers on erythropoiesis and myelopoiesis in human bone marrow long term cultures.

This report presents results concerning the potential role of negative regulators in hematopoietic suppression observed in human immunodeficiency virus (HIV)-infected long-term cultures (LTC) of human bone marrow cells. Confluent stromal cell layers established from human bone marrow cells were exposed to HIV-1ADA, a monocytotropic strain of HIV-1. A progressive increase in the concentration of HIV-1 p24 antigen in cultures exposed to HIV-1ADA demonstrated that there was a productive infection.

[Comparison of the planimetric and gravimetric methods in the study of the efficiency of endodontic instruments].

Both gravimetry (measurement of weight loss of roots after root canal preparation) and planimetry (measurement of surface area corresponding to the removed dentin layer of canal walls on oro-vestibular and mesio-distal X-ray views of roots before and after the preparation) were used on the same samples for determination of the efficacy of root canal shaping instruments. There were no statistically significant differences between the results obtained using either the gravimetry or the planimetry indicating the evidence of reliability of results obtained using only the planimetry as a single method.

Hereditary hyperparathyroidism-jaw tumor syndrome: the endocrine tumor gene HRPT2 maps to chromosome 1q21-q31.

The syndrome of hereditary hyperparathyroidism and jaw tumors (HPT-JT) is characterized by inheritance, in an autosomal dominant pattern, of recurrent parathyroid adenomas, fibro-osseous tumors of the mandible and/or maxilla, Wilms tumor, and parathyroid carcinoma. This syndrome is clinically and genetically distinct from other endocrine neoplasia syndromes and appears to result from mutation of an endocrine tumor gene designated "HRPT2." We studied five HPT-JT families (59 persons, 20 affected); using PCR-based markers, we instituted a genomewide linkage search after excluding several candidate genes.

Adenosine receptors mediate both contractile and relaxant effects of adenosine in main pulmonary artery of guinea pigs.

In guinea pig main pulmonary artery precontracted with noradrenaline, adenosine exerted an initial phasic contraction followed by a tonic contraction and a slow relaxation. After selective blockade by 1,3-dipropyl-8-cyclopentylxanthine (DPCPX: 10 nM) of A1 receptors, adenosine only elicited a rapid relaxation. This initial response was characterized by use of adenosine (AR) and its analogues N6-cyclopentyl-adenosine (CPA), R-N6-phenylisopropyladenosine (R-PIA), 2-chloroadenosine (CADO), 5'-N-ethyl-carboxamidoadenosine(NECA), N6-2-(4-aminophenyl) ethyl adenosine (APNEA) and 2-p-((carboxyethyl)-phenethylamino)-5'-carboxamidoadenosine (CGS 21 680).

First-trimester ultrasound screening for fetal aneuploidies in women over 35 and under 35 years of age.

In a prospective screening study, the utility of the thickness of first-trimester simple hygroma in sonographic screening for fetal chromosomal aberrations was examined. A total of 3380 women, 1280 of whom were 35 years or over, and 2100 of whom were under 35 years, were screened by ultrasound at 9-12 weeks of gestation. The thickness of fetal nuchal simple hygroma was measured.

[Effect of preparation methods on the adaptability of conventional amalgams and amalgams without gamma-2-phase].

Experimental investigations with "Goodfill 700" and "Starfill NG2" amalgams showed, that the adaptability and plasticity depend not only on characteristics of the powder, but are influenced by mixing ratios resp. methods of condensation. Fillings performed from "Starfill NG2", possessing a higher content of powder, but in spherical and smaller particles, have a better adaptability, however a more loose structure at the edges.

HCV antibodies in Hungarian blood donations. Experiences collected by ELISA tests, immunoblot assays and polymerase chain reaction and protocols for donor management.

Routine screening of Hungarian blood donors for anti-HCV commenced in the second half of 1992. Before this, five available anti-HCV ELISA kits were compared in pilot studies. In the first series, 831 random donor samples were tested by one of the tests and the 12 (1.

[The role of local excision in the surgical treatment of rectal cancer].

Unlabelled: Between 1984 and 1992 authors performed 307 surgical interventions for patients with rectal cancer, of these 199 operations were curative (65%). Local excision of the tumour was carried out in 9 cases: 2 with palliative intent, 7 were considered a curative treatment, that constituted 3.5% of all curative procedures.

[Synthesis of quinazolino-1,3-benzothiazine derivatives].

The ring-closure reactions of N-(3,4-dimethoxyphenylthio-methyl)-2-nitrobenzamide derivatives 5a,b with phosphoryl chloride gave 4-(2'-nitrophenyl)-2H-1,3-benzothiazine derivatives 7a,b, which on reduction yielded 4-(2'-aminophenyl)-3,4-dihydro-2H-1,3-benzothiazines 8a,b. Reaction of these compounds with phosgene led to the derivatives 9a,b of a new heterocyclic ring system, 6H,8H-quinazolino[3,4-c] [1,3]benzothiazine. The structures of the title compounds were proved by their ir and nmr (1H, 13C) spectra.