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Biomedical subjects

G Haase

Publications and source records attributed to G Haase.

At least 109 records · Page 6Linked to original sources
PubMed1991

Different promoters of SHV-2 and SHV-2a beta-lactamase lead to diverse levels of cefotaxime resistance in their bacterial producers.

Clinical Klebsiella pneumoniae isolates as well as Escherichia coli transformants producing the beta-lactamases SHV-2 or SHV-2a demonstrate MIC values for cefotaxime of 4 mg l-1 or 64 to greater than 128 mg l-1, respectively. The beta-lactamases differ by one possibly insignificant amino acid exchange at position number 10 of the mature protein; their kinetic parameters are rather similar. The 5' untranslated regions of both corresponding genes show no homology starting 74 nucleotides upstream to the start codon. Hybridization of intragenically annealing oligonucleotides to dot-blotted serial dilutions of total cellular RNA from E. coli transformants harbouring these genes cloned into the same vector plasmid gave a positive signal down to 1.2 micrograms (SHV-2) and 0.32 to 0.16 micrograms (SHV-2a), indicating a four to eight times higher amount of specific transcript in the case of SHV-2a. By primer extension analysis and S1 nuclease digestion the starting point to transcription was located 100 nucleotides (SHV-2) and 50 nucleotides (SHV-2a) in front of the start codon. No other transcripts of different length could be detected after prolonged exposure. Northern blot analysis demonstrated the length of the beta-lactamase mRNA to be about 1.6 kb in both cases, thus comprising a potential open reading frame downstream of the two enzymes' genes. Selective PCR amplification of both promoter regions and of the structural gene of SHV-2 and subsequent combined cloning of each of the promoters and the SHV-2 gene into pBGS19 using a BamHI restriction site introduced by three point mutations into the cloned sequences was employed to transforms E. coli DH5 alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1991

[Long-term fungal culture of sputum from patients with cystic fibrosis].

Mycological examination of sputum from 121 patients with cystic fibrosis by means of long-term culture (4 weeks) revealed the occurrence of Candida albicans in low quantities in 70%, Aspergillus fumigatus in 30%, and Exophiala/Wangiella dermatitidis in 9% of the examined patients. A. fumigatus causes frequently the development of allergic bronchopulmonary aspergillosis in patients with cystic fibrosis. The predisposing factors for colonization with the otherwise seldom recovered fungus E. dermatitidis in these patients and the consequences of these findings are discussed. In conclusion, long-term fungal cultures are advocated for specimens from CF patients.

Adolescent↗
PubMed1990

Better survival after combined modality care for adults with Wilms' tumor. A report from the National Wilms' Tumor Study.

Adults with Wilms' tumor (WT) have had a poor prognosis. More recently, therapies used in children, who have a better outlook, are also being employed for adults. This study was undertaken to see whether adults with WT have benefited. The results of treatment of 27 adults with WT were reported to the National Wilms' Tumor Study (NWTS) from 1979 to 1987. The ages of the 27 adults ranged from 16 to 74 years (median, 24 years). Four had anaplastic WT, and 23 had favorable histology (FH) WT. All but one patient underwent nephrectomy, 21 were given postoperative radiation therapy, and 25 received chemotherapy. The agents used most often included actinomycin D (AMD), vincristine (VCR), and doxorubicin (Adriamycin; ADR). There were six Stage I, five Stage II, four Stage III, 11 Stage IV, and one Stage V patients. The 3-year survival rate is 67%. These results are better than the 24% reported by the NWTS in the past for adults with WT. Analyses of the therapies given to the 27 adults lead to the following recommendations: for Stage I/FH patients, 6 months of postoperative chemotherapy using AMD + VCR without postoperative radiation therapy; and for Stage II, III, and IV/FH, VCR + AMD + ADR for 15 months + 2000 cGy to the tumor bed, 1200 to 1500 cGy to the lungs, 2000 cGy to the liver, and 3000 cGy to other sites as appropriate in patients with metastases at diagnosis.

Adolescent↗
PubMed1989

An improved broth-microdilution procedure for testing metal ion resistance of Klebsiella pneumoniae.

A new broth-microdilution method for testing metal ion resistance was designed in order to circumvent the formation of insoluble complexes between cations and compounds of the test medium. High-level cefotaxime resistant K. pneumoniae isolates tested by this procedure proved to be susceptible to Cd, Hg and Zn but resistant to Pb, Mo and W. The metal ion resistance was not linked to the beta-lactam resistance gene.

Cefotaxime↗
PubMed1988

An evaluation of the role of surgery in metastatic neuroblastoma.

The role of surgery was evaluated in 320 patients with metastatic neuroblastoma (Children's Cancer Study Group [CCSG] stage IV, excluding IV-S) enrolled in two CCSG treatment protocols between June 1978 and November 1982. The regimens consisted of combination chemotherapy, radiation therapy, and surgery. Two hundred seventy-seven surgical procedures were performed in 214 of the 320 eligible patients. Surgical intervention at the primary site was performed at initiation of therapy in 86 patients. There was a slight survival advantage when complete resection of the primary tumor was achieved (P = .09). Delayed surgery was performed in 89 patients. Gross complete resection of primary tumor was feasible in 57 of these patients (64.0%). However, survival analysis showed that resolution of metastases had a more important impact on subsequent length of survival than resectability at the delayed procedure (P = .005).

Adolescent↗
PubMed1981

The jejunal absorption of glucose oligomers in the absence of pancreatic enzymes.

We compared the absorption of carbohydrate from solutions of glucose oligomers and glucose in jejunal Thiry-Vella fistulae, a preparation deprived of pancreatic secretions. The studies were performed with two concentrations (90 and 360 mg/dl) of both glucose and the glucose oligomers. Carbohydrate absorption from glucose solutions (33.1 +/- 2.8, 115.9 +/- 8.9 micrograms/cm/min) was significantly greater (P less than 0.025; P less than 0.005) than that from oligomer solutions (26.6 +/- 2.1 and 92.4 +/- 9.0 micrograms/cm/min). Thin-layer analyses of the perfusates demonstrate digestion of oligomers with a chain length up to eleven and suggest digestion of oligomers of even greater chain length. Atrophy of the jejunal mucosa occurred over the course of the study as evidenced by a decrease in the ratio of villous height to crypt depth from 3.8 to 0.3, and by a 80% decrease in the activity of maltase, sucrase, and lactase. Atrophy was accompanied by a significant decline in the absorption of both glucose oligomers (P less than 0.005) and glucose (P less than 0.01) from the more concentrated solutions but the decrement in absorption of both carbohydrates was similar: glucose oligomers, 79.3 +/- 19.4 micrograms/cm/min; and glucose, 69.8 +/- 14 micrograms/cm/min (P greater than 0.20). Water absorption was enhanced by both carbohydrates, but there was no demonstrable difference between solutions of glucose and glucose oligomers. The osmolality of the solutions clearly influenced water absorption (P less than 0.025) but failed to effect the absorption of carbohydrates.

Animals↗