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G Geier

Publications and source records attributed to G Geier.

At least 19 recordsLinked to original sources
PubMed1999

Aspartyl proteases in Caenorhabditis elegans. Isolation, identification and characterization by a combined use of affinity chromatography, two-dimensional gel electrophoresis, microsequencing and databank analysis.

Crude homogenates of the nematode Caenorhabditis elegans exhibit maximal proteolytic activity under acidic pH conditions. About 90% of this activity is inhibited by the oligopeptide pepstatin, which specifically inhibits the activity of aspartyl proteases such as pepsin, cathepsins D and E or renin. We have purified enzymes responsible for this proteolytic activity by a single-step affinity chromatography on pepstatin-agarose. Analysis of the purified fraction by 1D SDS gel electrophoresis revealed six bands ranging from 35 to 52 kDa. After electrotransfer to poly(vinylidene difluoride) membranes, all bands were successfully subjected to N-terminal microsequencing. On 2D gels, the purified protein bands split into 19 spots which, after renewed microsequencing, were identified as isoelectric variants of the six proteins already described. The N-termini obtained for these proteins could be correlated to genomic DNA sequences determined in the course of the C. elegans genome sequencing project. All these sequences were predicted to code for expressed proteins as collected in the WORMPEP database. Five of the six coding sequences identified in this study were found to contain the typical active-site consensus sequence of aspartyl proteases and displayed an overall amino acid identity between 25 and 66% as compared to aspartyl proteases from other organisms. In addition to the five aspartyl proteases detected at the protein level, we have identified the coding sequences for seven other enzymes of this protease family by a similarity search in the genomic DNA of C. elegans which has recently been completely sequenced.

Amino Acid Sequence↗
PubMed1998

Cloning and characterization of a cDNA coding for Astacus embryonic astacin, a member of the astacin family of metalloproteases from the crayfish Astacus astacus.

The astacin family of zinc endopeptidases was named after the digestive enzyme astacin isolated from the crayfish Astacus astacus. Employing a reverse transcription/PCR strategy with degenerate oligonucleotide primers specific for two signature seqences of the astacin family, we have isolated a 1602-bp cDNA from embryos of developing A. astacus eggs, which was designated Astacus embryonic astacin (AEA). This cDNA was found to code for an astacin-like protease domain which accounts for the N-terminal half of the predicted protein. The C-terminal half mainly consists of two complement subcomponent C1r/C1s/embryonic sea urchin protein Uegf/bone morphogenetic protein 1 (CUB) domains. The metalloprotease domain displays an amino acid sequence identity of 42% with astacin. A higher sequence similarity was found to astacin family members that act as hatching enzymes in different species, e.g. chorioallantoic membrane protein 1 (CAM-1; from quail) and Xenopus hatching enzyme (formerly UVS.2), both of which show 54% identity, and high and low choriolytic enzymes (HCE and LCE) from the teleost Oryzias latipes (52% and 48% identity, respectively). A relationship to astacin-like hatching enzymes is further supported by a phylogenetic analysis of the protease domains. Expression of AEA mRNA in developing embryos was found to be restricted to unhatched juveniles (larvae) during the last 8 days before hatching. AEA transcripts could not be detected in various tissues of adult animals or in eggs and embryos from an earlier developmental stage. AEA expression starts about 8 days prior to hatching, followed by a strong (18-fold) induction with a maximum at day 4 before hatching. Newly hatched juveniles were found not to express the AEA mRNA.

Amino Acid Sequence↗
PubMed1997

Genomic organization of the zinc-endopeptidase astacin.

The crayfish digestive protease astacin is the first described member of the astacin family of zinc-endopeptidases, for which it is regarded as a prototype. We have isolated and characterized the genomic sequence of astacin which spans a region of 2616 bp. The coding sequence is distributed over five exons and is interrupted by four introns. It was observed that structurally and functionally essential units of the protein, like the three alpha-helices, the five beta-strands, the Zn-binding motif, and the Met turn are never disrupted by introns. The start site of transcription was determined by primer extension analysis, confirming the existence of a pre-pro-protein of 49 amino acids which so far had not been detectable at the protein level. In addition, when compared to the amino acid sequence of mature astacin, a carboxy-terminal extension of two additional amino acids was also found. The exon-intron pattern of the astacin gene was compared to those of three other astacin family members with known genomic sequences, i.e., tolloid of Drosophila, the fish hatching enzyme LCE, and the human BMP1 gene. In each of the four proteins one intron was found to be inserted in the codon for a similar Gly residue which is highly conserved in this position within the astacin family.

Amino Acid Sequence↗
PubMed1995

[The value of aspiration cytology within the scope of triple diagnosis of palpable breast changes].

The diagnostic value of aspiration cytology and the overall diagnostic quality of the so-called triple test (aspiration cytology, mammography and physical examination) in the evaluation of palpable breast masses were investigated in a retrospective study. 608 histologically evaluated cancers and 224 benign lesions were investigated. A main purpose of the study was to find out whether the triple diagnostic test can replace surgical biopsy and thereby reduce the number of unnecessary biopsies. All lesions triple-diagnosed as malignant were histologically proved to be malignant, i.e. there were no false positive results. The rate of false negative results was found to be within the range reported for false negative results in fresh frozen sections. Based on these results we state that the dogmatic statement "every palpable mass in the breast must be excised" should be replaced by the recommendation "every palpable mass must be assessed and clarified". A great number of retrospectively unnecessary biopsies can be avoided by a systematic use of the triple diagnosis. The diagnostic safety of this method is close to that of open biopsy. In all cases where positive or negative concordant triplets are found, histological confirmation by biopsy can be avoided. Patients with benign lesions can be thoroughly followed up by repeated physical and radiological examinations. Patients with triple diagnostic malignant results can be adequately treated. Lesions for which triple diagnosis yields neither benign nor malignant, must be biopsied: This is also necessary in all cases with suspicious findings in mammography without a palpable mass, if the equipment for stereotactic or ultrasound- guided biopsies is not available.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy, Needle↗
PubMed1990

Nerve-sparing retroperitoneal lymphadenectomy with preservation of ejaculation.

The feasibility of sparing postganglionic fibers of lumbar sympathetic nerves during the course of retroperitoneal lymphadenectomy has been investigated at our university medical center beginning in 1978. We selected 75 patients for nerve-sparing retroperitoneal lymphadenectomy in an effort to preserve ejaculatory function postoperatively. This cohort of patients was selected on the basis of clinical stage. Of the 75 patients 73 had clinical stage I disease. However, 14 of these 73 patients had pathological stage II cancer. No patient was treated with adjuvant chemotherapy after nerve-sparing retroperitoneal lymphadenectomy. Of these 14 patients with pathological stage II disease 4 had relapse: 1 with proved retroperitoneal recurrence, and 3 with serological elevations of tumor markers and questionable clinical findings as to anatomical site of relapse. All 4 patients are free of disease after chemotherapy and/or surgical (1) rescue. There were no local recurrences in the 61 patients with negative nodes. All 75 patients ejaculate and had no evidence of disease more than 2 years after nerve-sparing retroperitoneal lymphadenectomy. It is clear that nerve-sparing retroperitoneal lymphadenectomy is a feasible technique. As noted, it can even be applied to selected patients with low volume positive nodes, yet maintaining relapse and survival figures that are acceptable. Ejaculation is reliably preserved when this nerve-sparing technique is applied accurately in retroperitoneal lymphadenectomy.

Adrenergic Fibers↗
PubMed1987

Correlation of computerized tomographic changes and histological findings in 80 patients having radical retroperitoneal lymph node dissection after chemotherapy for testis cancer.

A total of 80 patients with stage B3 or B2/C germ cell testis tumors underwent computerized tomography before and after chemotherapy. The volume and computerized tomographic density of metastatic retroperitoneal tumor were measured on all scans. The patients then underwent full bilateral retroperitoneal lymphadenectomy. The change in volume and density of retroperitoneal disease was correlated with the histological type of the primary testis tumor and with the histological findings at retroperitoneal lymphadenectomy. In all 15 patients (100 per cent) without teratomatous elements in the original tumor and who had a greater than 90 per cent decrease in the volume of retroperitoneal masses as a response to systemic chemotherapy no teratoma or active cancer was found in the surgical specimen. In contrast, 7 of 9 patients (78 per cent) with teratomatous elements in the original specimen had either teratoma or carcinoma in the retroperitoneal lymphadenectomy specimens despite having a greater than 90 per cent decrease in tumor volume. This difference was significant (p less than 0.05). These data suggest that patients with no teratomatous elements in the original specimen and a greater than 90 per cent decrease in the volume of retroperitoneal masses in response to chemotherapy can be observed carefully for signs of recurrence rather than undergoing post-chemotherapy retroperitoneal lymphadenectomy.

Antineoplastic Agents↗
PubMed1986

[Effect of azelaic acid on the growth of melanoma cell cultures in comparison with fibroblast cultures].

Azelaic acid, a linear C9 dicarbonic acid, can effect a reduction in the growth of melanoma cells. This was shown in a comparison of two human melanoma cell cultures and cultured human skin fibroblasts. The cultures were observed for 24 days. The reduction in growth effected by azelaic acid showed significant differences concerning the dose-effect ratio in both melanoma cell lines observed. There was no inhibition of cell proliferation in the fibroblast cultures. Morphological and final trypan blue tests suggest that azelaic acid is not cytotoxic but cytostatic in a selective way.

Antineoplastic Agents↗
PubMed1983

[Phosphohexose isomerase in cyst fluids and effusions as a complement to cytological diagnosis].

Phosphohexose-isomerase concentration in cysts and effusions of various localisations was measured in 83 cases. The enzyme activity was compared with aspiration-cytologic results on the basis of histologic diagnoses. There is a reasonable correlation from cytologic cellularity and PHI-concentration. PHI-measurements give an additional information whether an aspirated fluid derives from a benign or a malignant lesion.

Ascitic Fluid↗
PubMed1983

[A comparative study on the obstetric aspects of epidural anaesthesia].

A retrospective analysis of 2,130 deliveries in 1980 was done. 42.21% of the women had epidural anaesthesia (EDA). They were compared with the 57.79% of the women, who did not have EDA. Decisive differences in both groups concerning age, fetal malposition, birth weight, umbilical artery pH and the Apgar score after one minute were not noted. There were more primiparous women in the EDA group and more women with a nationality other than German in the control group. Frequency of instrumental vaginal deliveries was extremely high in the EDA group as compared with the control group. In the EDA group a prolongation of labour especially the third stage was observed. A cesarian section due to an arrest in the process of labour was more often performed in the EDA group than in the control group. The suggestion is made that the relaxation of the pelvic floor and the diminuation of the bearing down reflex in EDA leads to a prolongation of labour and an increased instrumental delivery rate.

Adolescent↗
PubMed1982

[Diagnostic and therapeutic management of breast cysts].

In a study of 144 patients with cystic dysplasia of the breast diagnostic and therapeutic accuracy of palpation, mammography, aspiration cytology and pneumocystography was investigated. Only in 9.7% of the cases a surgical biopsy was necessary. In more than 90% of the cases biopsy was not performed; instead of this follow up with palpation, mammography and aspiration cytology up to 11 months was done. No breast cancer was overlooked, three of four proliferating dysplasias were detected. In 21% a local cystic recidive occurred which again was punctured. In contrary to surgical biopsy follow up of cystic dysplasias is not complicated by scars and their diagnostic problems. No complications were seen.

Biopsy↗
PubMed1981

[The influence of the urethral pressure profile on the prognosis of incontinence surgery (author's transl)].

In 114 out of 1215 stress-incontinent women the maximal urethral closure pressure was determined. Descensus of urinary bladder and urethra was proved by lateral urethrocystography. In the group of sphincter weakness (Edwards) which was to be found in 46 patients, only 48% became continent after colporrhaphy, Marshall-Marchetti-Krantz or sling surgery. If the pressure profile was found to be normal 74% of our patients felt cured after incontinence-operation. Sphincter weakness determines a failure due to surgery which is statistically of significance (P less than 0,01).

Female↗
PubMed1981

[Cytological differential diagnostic accuracy in severe dysplasia and carcinoma in situ of the cervix and possible clinical consequences (author's transl)].

Since 1943 when Papanicolaou introduced cytology into gynecology the method has changed from a simple screening test into a sophisticated morphologic technique, the differential cytology. In Germany this development is documented by an improved cytologic classification (Münchner Nomenklatur). An own material is presented consisting of 520 cases of histologically proven severe dysplasias and in situ carcinomas. It can be shown that careful and critical use of differential cytology with due regard to its limits can improve the accuracy of the cytologic prediction of a cervical lesion. A delineation against invasive cancer is possible with a hundred percent accuracy. On the basis of these results it seems justifiable to perform a primary hysterectomy without pretherapeutic cone-biopsy. It is pointed out that this procedure is only possible in institutions were the possibilities of differential cytology are well-known and--which is more important--where the limits of the method are known and respected. In any case of doubt the procedure of diagnosis and therapy has to be discussed and planned in close cooperation between the clinicians and the morphologists.

Carcinoma in Situ↗
PubMed1981

[Clinical anatomic and urodynamic investigations in stress-incontinence women (author's transl)].

In 398 patients suffering from urinary incontinence seven urodynamic parameters were investigated. 75% resp. 78% had a normal max. urethral closure pressure. Only a part of the women was characterized by a descensus of the genital tract. Some more patients showed anatomic abnormalities in the urethrovesical configuration by x-ray urethrocystogram. 1/5 res. 1/3 of descendent anterior vaginal walls proved to have a cystocele. If one requires for successful incontinence operation a normal max. urethral closure pressure and an objectively proven abnormality of the urethrovesical configuration, only 65% resp. 67% of our incontinence women have a chance of being cured by incontinence operation.

Female↗