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Biomedical subjects

A Buchholz

Publications and source records attributed to A Buchholz.

17 recordsLinked to original sources
PubMed1990

Inhibition of low Km cyclic GMP phosphodiesterases and potentiation of guanylate cyclase activators by cicletanine.

Cicletanine is an antihypertensive/vasorelaxant/natriuretic agent of unknown mechanism. We wished (a) to determine if cicletanine interacts with guanylate cyclase activators that modulate vasomotor tone and sodium balance [i.e., atriopeptin II (AP II), endothelium-derived relaxing factor (EDRF), and sodium nitroprusside (SNP)], and (b) to define the subcellular basis for this interaction by quantitating the effects of cicletanine on low Km cyclic GMP phosphodiesterase (PDE) activity. In phenylephrine-contracted rat aortic smooth muscle, the vasorelaxant potency of cicletanine was increased twofold in the presence of a threshold-relaxant concentration of AP II, and functional cyclic GMP PDE inhibition was also evident from the three- to sixfold potentiation by cicletanine of AP II- or SNP-induced vasorelaxation. Vasorelaxation produced by cicletanine was not endothelium dependent, however. In further studies, intravenous (i.v.) administration of cicletanine or the low Km cyclic GMP PDE inhibitor, zaprinast, decreased blood pressure (BP) greater than or equal to 20% in conscious spontaneously hypertensive rats (SHR). These results are consistent with the additional finding that cicletanine inhibited Ca2(+)-calmodulin (CaM) cyclic GMP PDE and zaprinast-sensitive cyclic GMP specific PDE over a concentration range (10-600 microM) similar to that for vasorelaxation. Thus, inhibition of low Km cyclic GMP PDEs by cicletanine may be partly responsible for the vasorelaxant effect of cicletanine as well as the potentiation by cicletanine of the vasorelaxant actions of guanylate cyclase activators. The extent to which this mechanism contributes to the antihypertensive efficacy of cicletanine has not yet been fully determined.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1990

[An unusual benign hamartomatous tumor of the lung].

About a rare benign tumor of the lung of a fifty-nine years old woman is reported. The possible relation to the group of the pulmonary hamartomas is discussed. The tumor was benoted as "Benign angiohamartomatous tumor".

Endothelium, Vascular↗
PubMed1990

[Mullerian adenosarcoma].

The Müllerian adenosarcoma is an extremely rare entity of tumours of the group of the Müllerian and mesodermal mixed tumours. This tumour seems to be a malignant transformation of the uterine papillary cystadenofibroma. The periglandular malignant transformation of the stromal component and the benign glandular structures are typical signs of the Müllerian adenosarcoma. In accordance with references the prognosis of the adenosarcoma is better than those of other Müllerian mixed tumours. The demonstrated cases warn against undervalue.

Aged↗
PubMed1990

[Struma ovarii. Short report of 2 cases].

A 75-year old and a 48-year old woman were treated by hysterectomy and unilateral adenectomy. The extirpated ovarian tumors both have shown histologically the structures of Struma ovarii with monodermal differentiation. The Struma ovarii represents a rare special manifestation of mature teratoma with typical histological appearance. At similarities to original thyroid tissue are given directions.

Aged↗
PubMed1989

Cell-line-dependent inhibition of phenotypic expression of preneoplastic and neoplastic tracheal epithelial cells by normal tracheal cells in denuded tracheal transplants.

The inhibitory role of normal cells on the expression of neoplastic or preneoplastic cells was investigated using repopulated, heterotopic tracheal transplants. Denuded tracheal transplants were repopulated with a constant number of cells composed of different ratios of normal and neoplastic or preneoplastic rat tracheal epithelial (RTE) cells. Tracheas were harvested at 2 and 6 weeks after implantation, and examined histologically and in cell culture for the presence of the abnormal cells. Two neoplastic cell lines showed marked differences in the number and extent of squamous cell carcinomas which developed in tracheas repopulated at equivalent ratios of RTE: neoplastic cells. One preneoplastic cell line was almost completely inhibited in proliferative and phenotypic expression by normal cells, in contrast to a marked lack of suppression by normal cells of a second preneoplastic cell line. The extent of squamous metaplasia present, or the presence of invasive squamous cell carcinoma, was dependent upon the cell line instilled, suggesting that the cell lines represent different stages in the progression toward neoplasia. The lack of inhibition of some tumorigenic or preneoplastic cells by normal cells in this study is in conflict with previously published reports which indicate that the presence of greater than 10(4) normal cells are capable of inhibiting neoplastic expression in this model. Based on these studies, it appears that the nature of the neoplastic or preneoplastic cell is critical in determining whether inhibition by normal cells can occur.

Animals↗
PubMed1989

[A membrane-bound alanine aminopeptidase from Acinetobacter calcoaceticus. 2. Substrate specificity of the enzyme].

The substrate specificity of the membrane-bound alanine aminopeptidase from Acinetobacter calcoaceticus was investigated with a series of substituted amides of alpha-amino acids. In contrast to mammalian AAP forms, the rate of hydrolysis of the AAP from Acinetobacter calcoaceticus is higher using 4-nitranilide than 2-naphthylamide substrates. The enzyme affinity is very high for alanine substrates and decreases in the series of the amide substituents, from methyl coumarylamides, 4-nitranilides, 4-methoxynaphthylamides to the 2-naphthylamides. The alanine aminopeptidase shows its highest affinity to Ala-MCA (Km = 77 mumol(s)/1).

Acinetobacter↗
PubMed1987

Use of adherence protein of Mycoplasma pneumoniae as antigen for enzyme-linked immunosorbent assay (ELISA).

Antibodies against the adherence protein of Mycoplasma pneumoniae are regularly found in patients with M. pneumoniae infection. Therefore, this 168-kilodalton (kDa) protein was used as an antigen in a dot-ELISA for serological diagnosis of M. pneumoniae disease. M. pneumoniae proteins were separated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), gels were stained with Coomassie Blue, and the 168-kDa protein band was cut out and eluted using a special electroelution device. Isolated proteins or sonicated whole-cell antigens, respectively, were immobilized on a 96-well filtration plate with a nitrocellulose bottom (dot-ELISA). The test procedure was performed as in conventional ELISA tests, using alkaline phosphatase-labeled antihuman IgM or IgG antibodies, respectively, to detect antigen-antibody complexes. All results were confirmed by immunoblotting. The dot-ELISA using the 168-kDa antigen proved to be sensitive and specific. The specificity was tested on 53 sera of M. pneumoniae infections and on 490 serum specimens of patients with other respiratory diseases due to other pathogens, or with clinical conditions such as pancreatitis, meningitis or endocarditis. With regard to IgM antibodies, no false-positive reactions were found in non-M. pneumoniae diseases against the 168-kDa antigen, but there were such reactions against other M. pneumoniae proteins in immunoblots.

Adhesins, Bacterial↗
PubMed1986

[Cryosurgical treatment of cervical intraepithelial neoplasia following cervical smears and curettage].

65 patients exhibiting colposcopically and cytologically atypical epithelium in the cervix were treated by cryosurgery with liquid nitrogen. 63 of whom were confirmed histologically after surface scraping and curettage of the cervix. The patient then were followed cytologically and colposcopically 8 and 12 weeks after cryosurgery. According to that the definitive histological diagnosis was performed after conization (48 patients) hysterectomy (12 patients) and surface scraping and curettage of the cervix (8 patients). Colposcopical, cytological and histological findings after surface scraping of the cervix showed a correlation rate in the 95% range. Treatment failure rate following cryosurgery showed an increased percentage with increased grade of CIN. A complete destruction of ectocervical pathologic tissue in CIN 1 and 2 is opposed to a persistent disease rate of 20 percent in patients with CIN 3. The failure rate was significantly higher in cases without fully visualization of squamocolumnar junction. Cytological follow-up predicted all cases with histologic diagnosis of persistent disease. Colposcopical evaluation was frequently unsatisfactory after cryosurgery. Cryosurgery of CIN should be reserved for the treatment of those patients in whom the criteria for patient selection are performed and the benefits of this method outweigh the possible drawbacks.

Carcinoma in Situ↗
PubMed1978

[Thorotrast carcinoma of the lung--contribution to the genesis of carcinoma after application of thorotrast and of old bullet wound (author's transl)].

A bronchogenic carcinoma was found in the sphere of the scar in a fifty-years-old man who suffered in 1945, 27 years before his death, from a pulmonary bullet wound caused by war influence. The histological examination furthermore disclosed considerable autoradiographic secured deposits of thorotrast in the carcinoma and scar sphere. One may suppose that in connection with the treatment of the results of this injury a bronchography or a preparation of the fistula followed. All available cases of a beginning of carcinoma after a pulmonary bullet wound as well as all cases of carcinoma of the lungs after thorotrast incorporation found in literature were collected, critically sorted out and represented in schedules. A summary of questions of the causes and pathogenesis is given.

Carcinoma, Bronchogenic↗
PubMed1978

[Fibrosarcoma of the right ventricle of the heart--a contribution to the pathology of the primary sarcoma of heart and pulmonary arteries (author's transl)].

The clinical signs as well as the pathological-anatomical and histological peculiarities of a case of fibrosarcoma of the right ventricle of the heart in a fifty-years-old women are described. Examining of all cases described in literature it becomes evident that when ascertaining the starting points, there is a fluent transition from the sarcoma of the endocardium to the sarcoma of the pulmonary arteries. Four types become evident. The morphological pecularities of the appearance of Anitschkow-cells are described. Origin and importance of these cells are not known yet in all their details. The Survey over the single observations speaks in favour of their affiliation to the cellular defence system of the heart.

Female↗
PubMed1978

[Coincidence of chronic lymphadenosis and lymphogranulomatosis].

A case is reported on the joint presence of chronic lymphatic leukaemia and lymphogranulomatosis in a 58 years old patient. 5 years after diagnosis and therapy of lymphadenosis a lymphogranulomatosis existing in addition to lymphadenosis was discovered by autopsy. Previously a change of symptoms had occurred. This became evident in the regression of palpable lymph node swellings as well as leukocytosis and lymphocytosis, in a change of the differential blood picture and the presence of periodic subfebrile temperatures. Problems connected with these double neoplasias are briefly outlined and discussed.

Hodgkin Disease↗