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Biomedical subjects

D Fischer

Publications and source records attributed to D Fischer.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of the polymerase chain reaction (PCR) for detection of Chlamydia psittaci in abortion material from ewes.

The polymerase chain reaction (PCR) was evaluated as a diagnostic tool for detection of Chlamydia (C.) psittaci in abortion material from 40 ewes. For this purpose, PCR results of 87 samples were compared with direct microscopic identification after chemical staining, cell culture isolation and a commercially available enzyme-linked immunosorbent assay (ELISA). The value for sensitivity as compared to cell culture was 97.7% whereas the specificity-value was calculated to be 84.1%.

Abortion, Veterinary↗
PubMed1992

An efficient automated computer vision based technique for detection of three dimensional structural motifs in proteins.

As the number of available three dimensional coordinates of proteins increases, it is now recognized that proteins from different families and topologies are constructed from independent motifs. Detection of specific structural motifs within proteins aids in understanding their role and the mechanism of their operation. To aid in identification and use of these motifs it has become necessary to develop efficient methods for systematic scanning of structural databases. To date, methods of structural protein comparison suffer from at least one of the following limitations: (1) are not fully automated (require human intervention), (2) are limited to relatively similar structures, (3) are constrained to linear alignments of the structures, (4) are sensitive to insertions, deletions or gaps in the sequences or (5) are very time consuming. We present a method to overcome the above limitations. The method discovers and ranks every piece of structural similarity between the structures compared, thus allowing the simultaneous detection of real 3-D motifs in different domains, between domains, in active sites, surfaces etc. The method uses the Geometric Hashing Paradigm which is an efficient technique originally developed for Computer Vision. The algorithm exploits the geometrical constraints of rigid objects, it is especially geared towards recognition of partial structures in rigid objects belonging to large data bases and is straightforwardly parallelizable. Computer Vision techniques are for the first time applied to molecular structure comparison, resulting in an efficient, fully automated tool. The method has been tested in a number of cases, including comparisons of the haemoglobins, immunoglobulins, serine proteinases, calcium binding proteins, DNA binding proteins and others. In all examples our results were equivalent to the published results from previous methods and in some cases additional structural information was obtained by our method.

Amino Acid Sequence↗
PubMed1992

Identification and molecular analysis of glgS, a novel growth-phase-regulated and rpoS-dependent gene involved in glycogen synthesis in Escherichia coli.

The putative stationary-phase sigma factor (sigma S) encoded by rpoS is essential for glycogen synthesis, but is not required for the transcription of glgC and glgA, which encode ADP-glucose-pyrophosphorylase and glycogen synthase, respectively. Using a mini-Mu random chromosomal library and a screen for glycogen overproduction, we identified a novel gene (glgS) involved in glycogen synthesis. glgS maps at 66.6 min (3247 kb) on the chromosome and constitutes a monocistronic operon. It encodes a hydrophilic and highly charged small protein, with a molecular weight of 7886, which is strongly expressed in minicells. Experiments with single-copy chromosomal glgS::lacZ gene fusions indicated that glgS expression is controlled by sigma S as well as by cAMP. Two transcriptional start sites were mapped in the upstream regulatory region of glgS. The glgSp1 transcript was absent in a cya mutant, whereas an rpoS mutant did not synthesize the glgSp2 transcript. Although glycogen synthesis is strongly stimulated by overproduction of GlgS and is inhibited by a glgS null mutation, glgS does not affect the expression of the glgCAP operon. Its potential role in the metabolic control of glycogen synthesis is discussed. Also, evidence is presented to show that the amount of glycogen accumulated in vivo in early stationary-phase cells is mainly determined by sigma S-controlled gene expression and allosteric activation of GlgC, whereas the absolute levels of expression of glgCAP as well as the intracellular concentration of cAMP are of minor importance.

Amino Acid Sequence↗
PubMed1992

Prognostic value of DNA flow cytometry in the locally recurrent, conservatively treated breast cancer patient.

PURPOSE: This study attempted to determine the prognostic value of DNA flow cytometry in the treatment of patients with locally recurrent, conservatively treated breast cancer. METHODS AND MATERIALS: Of 433 patients with clinical stage I and II breast cancer treated with conservative surgery and radiotherapy at Yale-New Haven Hospital before January 1985, 50 patients experienced an ipsilateral breast relapse as a first site of treatment failure. Using standard flow-cytometric techniques, DNA ploidy, DNA index, and S-phase fraction (SPF) were measured for 38 of the 50 (76%) paraffin-embedded specimens available for analysis. RESULTS: At a median postrecurrence follow-up of 5.8 years, the 5-year and disease-free survival rates following ipsilateral breast treatment failure were 48% and 54%, respectively. Sixty-three percent of the recurrent tumors were DNA diploid and 37% were aneuploid. Both DNA ploidy and SPF were statistically significant prognostic indicators for 5-year survival and disease-free survival after local recurrence. The 5-year survival rate of the DNA diploid population was 64%, compared with 15% in the aneuploid population (P < .02). Patients with low SPF (< 12%) experienced an 83% 5-year survival rate, compared with a 24% 5-year survival rate in patients with high SPF (> or = 12%) (P < .03). Ploidy and SPF were combined to define the categories of favorable (diploid, low SPF) and unfavorable (diploid, high SPF or any aneuploid subgroups). Patients in the favorable category experienced an 89% 5-year postrecurrence survival rate and a 100% disease-free survival rate, whereas patients in the unfavorable category had a 24% 5-year survival rate and a 32% disease-free survival rate (P < .01). The flow cytometry as a factor correlated with other clinical parameters previously shown to be of prognostic significance in this patient population. In a multivariate analysis, flow cytometry was a statistically significant and independent prognostic factor for disease-free survival following local recurrence. CONCLUSIONS: DNA ploidy and SPF as measured by currently available flow-cytometric techniques show promise as a tool in determining prognosis for the patient with locally recurrent breast cancer. Implications of these findings with respect to issues of adjuvant systemic therapy at the time of local recurrence are discussed.

Adult↗
PubMed1992

[Severe psychiatric disorders associated with severe acute colitis].

Acute colitis occurring in patients suffering from psychiatric illnesses is believed to be linked to the intake of psychotropes. From 1983 to 1989, the authors observed, in three Hepato-gastroenterology units, 10 cases of acute colitis in patients suffering from serious psychiatric disorders, most of them inpatients of mental hospitals. The detailed study of 7 of these cases emphasized a certain number of common features: there was no previous history of digestive disease, the psychiatric illness was serious and longstanding, acute colitis was severe, and there was no recurrence during clinical and endoscopic follow-up averaging 4.3 years. Of these 7 patients, 2 were not taking psychotropes at the time of colitis or after, 2 had discontinued their treatment for a few days, and 2 had not stopped taking psychotropes. One patient died. The short-term and long-term evolution in these cases was not influenced by the intake or not of psychotropes. The pathogeny of this colitis is yet to be determined: infection is the most likely origin.

Acute Disease↗
PubMed1991

Mammographically detected breast cancer. Results with conservative surgery and radiation therapy.

At Yale-New Haven Hospital (New Haven, CT) treatment of early stage breast cancer with conservative surgery and radiation therapy (CS & RT) has been utilized with increasing frequency since the 1960s. The authors have reviewed their experience with specific reference to the outcome of those patients whose breast cancer was detected on routine screening mammography. To achieve adequate follow-up, only patients treated before December 1984 are included in this analysis. Of 438 patients treated with CS & RT before December 1984, a total of 41 patients (9%) had nonpalpable lesions detected on routine screening mammography and were treated with CS & RT to the intact breast. Only two patients received adjuvant hormonal therapy and no patients received adjuvant systemic therapy. There has been only one breast failure and one death due to cancer in this group of patients resulting in actuarial survival and breast recurrence-free rates of 100% at 5 years and 92% at 10 years. These results stress the importance of routine screening mammography and raise questions regarding the role of adjuvant systemic therapy in this selected group of patients.

Adult↗
PubMed1991

Assigning functions to nucleolar structures.

Nucleoli provide the fascinating possibility of linking morphologically distinct structures such as those seen in the electron microscope with biochemical features of the formation and stepwise maturation of ribosomes. Localization of proteins by immunocytochemistry and of rRNA genes and their transcripts by in situ hybridization has greatly improved our understanding of the structural-functional relationships of the nucleolus. The present review describes some recent results obtained by electron microscopic in situ hybridization and argues that this approach has the potential to correlate each step of the complex pre-rRNA maturation pathway with nucleolar structures. Evidence is accumulating that the nucleolus-specific U3 snRNPs (small nuclear ribonucleoprotein particles) participate in rRNA processing events, similar to the role played by the nucleoplasmic snRNPs in mRNA maturation. The intranucleolar distribution of U3 snRNA is consistent with the view that it is involved in both early and late stages of pre-rRNA processing.

Animals↗
PubMed1991

Pharmacokinetics of recombinant interferon alpha-C.

Recombinant interferon alpha-C (rIFN alpha-C, Interpharm), is a new type of alpha-interferon that has a specific activity of 1-2 x 10(9) units/mg protein. The pharmacokinetics of rIFN alpha-C were studied in 11 patients with metastatic renal-cell carcinoma. A total of 10 million units IFN alpha-C were injected intramuscularly and the serum level of IFN was evaluated up to 72 h post-administration. Measurable IFN concentrations appeared in the serum as early as 0.5 h, and levels peaked at 4-6 h (Cmax = 53.2 +/- 4.6 units/ml). Relatively high levels persisted for 24 h and declined thereafter with an apparent half-life of 3-4 h. The mean area under the serum-concentration curve (AUC) was 1,259 +/- 145 units h ml-1, indicating good bioavailability of the preparation from the intramuscular injection.

Aged↗
PubMed1991

Sulindac causes regression of rectal polyps in familial adenomatous polyposis.

In familial adenomatous polyposis, sulindac-induced polyp regression has been reported by several authors. In this study, the goal was to confirm these results by a randomized, placebo-controlled, double-blind crossover study in 10 patients with rectal polyps that had been previously treated by colectomy and ileorectal anastomosis. Patients received sulindac, 300 mg/day, or placebo during two 4-month periods separated by a 1-month wash-out phase. One patient was not compliant and was excluded. With sulindac, the authors observed a complete (6 patients) or almost complete (3 patients) regression of the polyps. With placebo, the authors observed an increase (5 patients), no change (2 patients), and a relative decrease (2 patients) in the number of polyps. The difference between sulindac and placebo was statistically significant (P less than 0.01). In biopsy specimens of polyps and normal rectal mucosa of 6 patients, the authors conducted an immunohistochemical study of the cellular proliferation index using the Ki 67 monoclonal antibody (Ki 67 index), at the beginning and at the end of each treatment period. They were not able to show a sulindac-induced modification of the Ki 67 index. The authors conclude that sulindac is effective in inducing the regression of rectal polyps in familial adenomatous polyposis.

Adenomatous Polyposis Coli↗
PubMed1991

Clinical, psychological and thallium stress studies in patients with chest pain and normal coronary arteries.

The clinical and psychological profiles of 36 consecutive patients with chest pain and normal coronary arteries (study group) were compared to those of 34 patients with chest pain and significant coronary arterial disease (control group). All 70 patients were hospitalized for chest pain at least once prior to coronary angiography. The features of a typical episode of chest pain were similar in the normal coronary arteries and coronary arterial disease groups, but the female patients with normal coronary arteries had a shorter duration of a typical episode of chest pain, and the male patients with normal coronary arteries had a lower frequency of positive effort tests. Psychological testing showed the women with normal coronary arteries to have a tendency to increased somatization, anxiety, and a lower ability to identify origin of difficulties. The patients in the normal coronary and coronary arterial disease groups had psychological profiles typical of patients with chronic somatic disease. A psychiatric interview demonstrated an increased frequency of depressive trait (score 0-2) in the normal women (0.6 +/- 0.8 vs 0, P less than 0.05), and a tendency to increased somatization, anxiety, and sleeping disorders. Increased somatization was found in the normal coronary men (1.1 +/- 0.7 vs 0.5 +/- 0.7, P less than 0.05). Twenty-five patients of the normal coronary group underwent quantitative thallium stress studies, and 13 patients (52%) had evidence of stress-induced myocardial perfusion defect. There were no differences in the clinical and psychological profiles of the patients with normal and those with pathological thallium stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Chest Pain↗
PubMed1991

Expression of transforming growth factor-alpha and epidermal growth factor receptor in human fetal kidneys.

Beginning at the fifth week of fetal life, successive generations of individual nephrons are induced by contact between metanephric mesenchyme and ureteric bud. Following phenotypic transformation, cells of each primitive renal vesicle undergo a phase of rapid cell division. In order to identify genes which might regulate nephron development in man, we screened adult and fetal kidney RNA for expression of a panel of growth-related genes. Among the genes which were expressed at higher levels in fetal kidney was the epidermal growth factor (EGF) receptor. There is controversy as to the most likely physiologic EGF receptor ligand in fetal kidney; we were able to identify a transcript for transforming growth factor-alpha (TGF-alpha) but not EGF on Northern blots of fetal kidney RNA. Since the abundance of TGF-alpha mRNA is low, we confirmed its presence by polymerase chain reaction amplification. Using specific radioimmunoassays, we also provide direct evidence for TGF-alpha but not EGF peptide in extracts of fetal kidney and mid-gestational amniotic fluid. We suggest that TGF-alpha/EGF receptor interactions may serve an important function in development of human fetal kidney.

Base Sequence↗
PubMed1991

Prognosis following local recurrence in the conservatively treated breast cancer patient.

At Yale-New Haven Hospital conservative treatment of early stage breast carcinoma with lumpectomy and radiation therapy has been used with increasing frequency since the 1960s. We have reviewed our experience with specific reference to prognosis following local recurrence. Between January 1962 and December 1984 a total of 433 patients were treated with conservative surgery and radiation therapy using standard techniques. As of December 1989, with minimum evaluable follow-up of 5 years and a median follow-up of 8.21 years, there have been a total of 50 ipsilateral breast recurrences resulting in a 5-year actuarial breast recurrence rate of 8%. Extent of disease at the time of local recurrence was clinically categorized as localized (less than 3 cm without dermal involvement) or diffuse (greater than 3 cm and/or with dermal involvement). Seventy-two percent of the recurrences were at or near the original tumor site whereas 28% recurred elsewhere in the breast. At a median follow-up post recurrence of 5.0 years (range 0.3-16.9 years), the 5-year actuarial survival for breast recurrences was 59% and the 5-year disease-free survival was 65%. A number of clinical and pathological features at the time of original diagnosis as well as at the time of local recurrence were tested as possible prognostic indicators for survival following local recurrence. By univariate analysis, significant factors associated with survival following local recurrence included extent of local disease at the time of recurrence (p less than .01), time to local recurrence (p less than .03), with later recurrences doing better, and site of local recurrence (p less than .01), with recurrences elsewhere in the breast doing better. We conclude from this large single institutional experience with a median follow-up post-recurrence of over 5 years that patients experiencing a local recurrence in the conservatively treated breast have a relatively favorable prognosis. The prognostic factors correlating with survival and implications regarding adjuvant systemic therapy at the time of local recurrence are discussed.

Adult↗
PubMed1991

Prognostic factors for local recurrence in the conservatively treated breast cancer patient: a cautious interpretation of the data.

Between 1962 and 1984, a total of 433 patients were treated at Yale-New Haven Hospital with conservative surgery and radiation therapy (CS + RT) to the intact breast. As of January 1990, with a minimum assessable follow-up of 5 years and a median follow-up of 8.21 years, there have been a total of 50 breast recurrences resulting in a 5-year actuarial breast recurrence rate of 8%. Of all clinical factors tested, young age was the most significant prognostic factor for local recurrence (P less than .03). In addition, patients with pathologically involved lymph nodes were noted to have a lower local recurrence rate than patients with pathologically negative axillae (P less than .05). These findings were especially notable given the fact that the node-positive group had a higher percentage of T2 tumors and a higher percentage of patients in the young age group. These paradoxical findings, however, may be explained by the fact that 88% of the node-positive patients underwent adjuvant systemic therapy in the form of either systemic chemotherapy or hormonal therapy, while only 8% of node-negative patients underwent any adjuvant systemic therapy. When analyzed as a function of adjuvant therapy, those patients receiving adjuvant therapy had a lower local recurrence rate than those patients not receiving adjuvant therapy (P less than .08). We conclude that adjuvant systemic therapy impacts on the ipsilateral breast recurrence rate in patients treated with CS + RT. The implications of this study in light of the widespread use of adjuvant systemic therapy are discussed.

Actuarial Analysis↗
PubMed1991

[Controlled rubella vaccination at the Stuttgart Public Health Center].

Experience has shown that mass vaccination of pre-puberty girls against rubella (German measles), as recommended in accordance with German legislation and performed by the Public Health authorities, is unnecessary in about three-quarters of all the girls. Besides, only relatively few girls report for such vaccination. It became possible to carry out on-target vaccination by conducting first of all a serological preliminary test with capillary blood. This pin-pointed those pupils who were likely to be susceptible to rubella infection. After the vaccination, this method enabled re-checking by means of a further antibody test. All the pupils who had been successfully vaccinated or were already satisfactorily protected, were issued a certificate to that effect. In our opinion, the increased material and personnel expenditure of such on-target vaccination is justified by the fact that the rate of participation on the part of the pupils is markedly higher, so that vaccination becomes more meaningful than before.

Adolescent↗