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Biomedical subjects

A Richter

Publications and source records attributed to A Richter.

At least 325 records · Page 18Linked to original sources
PubMed1991

Structure of the human type I DNA topoisomerase gene.

We describe the molecular organization of the human gene coding for type I DNA topoisomerase. The coding sequence is split into 21 exons distributed over at least 85 kilobase pairs (kb) of human genomic DNA. The sizes of the 20 introns vary widely between 0.2 and at least 30 kb and all contain the sequence elements known to be required for pre-mRNA splicing. Several of the intron sequences separate exons encoding parts of the enzyme that are highly conserved between human and yeast suggesting that at least some of the exons may code for individual, structurally, or functionally important domains of the enzyme. We also describe the promoter sequence of the human topoisomerase I gene and show that it is composed of distinct functional elements.

Amino Acid Sequence↗
PubMed1991

Prognosis in acute myocardial infarction in relation to development of Q waves.

In a totally nonselected group of patients with acute myocardial infarction (AMI) (n = 921) admitted from the emergency department to the coronary care unit or other hospital ward, the occurrence of non-Q-wave AMI and the prognosis in these patients was determined and compared with those in whom Q waves were developed. Fifty-two percent had AMI without new Q waves. Patients with a non-Q-wave AMI differed from patients with Q-wave AMI, more frequently having a previous history of AMI (p less than 0.001), angina pectoris (p less than 0.01), diabetes mellitus (p less than 0.05), congestive heart failure (p less than 0.001), and a higher mean age (p less than 0.001), whereas smoking was more common in Q-wave AMI. Patients with non-Q-wave AMI had a 1-year mortality of 31% compared with 26% in Q-wave AMI (p greater than 0.2) and a reinfarction rate of 20% compared with 12% for Q-wave AMI (p less than 0.01). Among patients aged less than 75 years without a previous history of AMI, congestive heart failure, and diabetes mellitus, the 1-year mortality rate was 16% for patients with Q waves versus 15% for those without Q waves (NS). Appearance of Q waves was not independently associated with death. We conclude that in a nonselected group of patients with AMI the occurrence of a non-Q-wave AMI is much higher than previously reported. The prognosis in AMI during one year of follow-up is not associated with development of Q waves.

Aged↗
PubMed1991

Air embolism and pulmonary interstitial emphysema in a preterm infant with hyaline membrane disease.

A preterm infant with severe hyaline membrane disease requiring extreme mechanical ventilation developed pulmonary air leaks with consecutive shock. The chest roentgenogram showed bilateral pulmonary interstitial emphysema and gas within the heart silhouette as well as in the hepatic veins, inferior v. cava, portal vein, and many abdominal vessels. The respiratory and circulatory failure by massive systemic gas embolism resulted in death.

Embolism, Air↗
PubMed1991

One-year mortality rate after discharge from hospital in relation to whether or not a confirmed myocardial infarction was developed.

Consecutive patients admitted to our hospital with suspected acute myocardial infarction during 21 months were prospectively evaluated. One-year mortality after discharge from hospital was related to whether or not an infarction developed (infarct versus non-infarct patients). Of patients discharged alive after developing an infarct, there was a mortality of 17% (n = 777) versus 12% (n = 1830) (P less than 0.001) for all patients not developing infarction. In a high risk group (any of the following: age greater than or equal to 75 years, previous history of myocardial infarction, diabetes mellitus or congestive heart failure) patients developing infarction had a mortality of 24% (n = 457) versus 17% (n = 1221) for those who did not (P less than 0.001). In a low risk group (none of the high risk criteria), the corresponding mortality was 8% (n = 316) for patients suffering infarction and 3% (n = 603) for those not having infarction (P less than 0.001). The difference in mortality between patients with and without infarction was most marked in women (21% vs 11%; P less than 0.01) and in hypertensives (25% vs 12%; P less than 0.001), but less marked in men (16% vs 13%; NS) and in patients without hypertension (13% vs 12%; NS). Among patients not suffering infarction, mortality was particularly high in those with previous congestive heart failure (23%) and diabetes mellitus (21%).

Age Factors↗
PubMed1991

Effect of acupuncture in patients with angina pectoris.

Twenty-one patients with stable effort angina pectoris were randomized in a crossover study to 4 weeks traditional Chinese acupuncture or placebo tablet treatment. The patients had at least five anginal attacks per week in spite of intensive treatment. Acupuncture was given three times per week at main points Neiguan (Pericardium 6), Tongli (Heart 5), Xinshu (Urinary Bladder 15), Pishu (Urinary Bladder 20) and Zusanli (Stomach 36). Previous antianginal treatment remained unchanged during the whole study. During the acupuncture period, the number of anginal attacks per week was reduced from 10.6 to 6.1 compared with placebo (P less than 0.01). Accordingly, the performance before onset of pain during exercise test increased from 82 W to 94 W (P less than 0.05). However, maximal performance did not increase after acupuncture. Intensity of pain at maximal workload decreased from 1.4 to 0.8 (scale 0-4, P less than 0.01). Further, ST-segment depressions at maximal comparable load decreased from 1.03 to 0.71 mm after acupuncture (P less than 0.01). A life quality questionnaire confirmed improved feeling of well-being. Thus, acupuncture showed an additional beneficial effect in patients with severe, intensively treated angina pectoris.

Acupuncture Analgesia↗
PubMed1991

Prognosis in patients with ST-T changes but no rise in serum enzyme activity as compared with non-Q-wave infarction.

We evaluated the prognosis for 419 patients admitted to hospital due to suspected acute myocardial infarction (AMI) who developed ST-T changes, but no rise in serum enzyme activity, and compared it to that of 508 patients developing non-Q-wave AMIs. We conclude that these patients have a high 1-year mortality (13%), although significantly lower than in patients with non-Q-wave AMIs (31%). The mortality is higher in patients with only ST depression (n = 86; 22%) than in patients with only T-wave inversion (n = 264; 8%).

Aged↗
PubMed1991

Effects of carotenoid administration on bladder cancer prevention.

Bladder cancer was induced in male B6D2F1 strain mice by the administration of N-butyl-N-(4-hydroxybutyl)nitrosamine. Mice supplemented with beta-carotene for 5 weeks before receiving the carcinogen and maintained on beta-carotene for an additional 26 weeks developed significantly fewer tumors than did unsupplemented mice. Mice receiving canthaxanthin for the same time period showed no protection against the development of bladder cancer.

Animals↗
PubMed1991

[Coincidence of sigmoid cancer and sigmoid diverticulitis].

From 1985 to 1989 265 patients with a carcinoma of the sigmoid or sigmoid diverticulitis have been operated in our clinic. 23 of the treated patients synchronously had a carcinoma and a diverticulitis. The carcinoma in these cases was found to be significantly more frequent in a stage T1 or T2. We also found a significantly higher rate of perforations in this group of patients.

Adenocarcinoma, Mucinous↗
PubMed1991

[Estrus and ovulation synchronization in Merino meat sheep. 1. Effect of Gonavet "Berlin Chemie" after estrus synchronization with prostaglandin F2 alpha in Merino meat sheep].

Oestrus synchronisation by means of PGF2 alpha analogues was followed by injection of Gonavet "Berlin-Chemie" which triggered off an LH peak, 2 to 3 hours from injection. Injection of Gonavet "Berlin-Chemie", 44 hours after PGF2 alpha application, caused synchronisation of all LH peaks. The interval between injection of Gonavet "Berlin-Chemie" and onset of ovulation amounted to 22 hours. The length of ovulation was not accurately determinable. Ovulation was successfully induced to all sheep by application of Gonavet "Berlin-Chemie", 44 or 48 hours after PGF2 alpha injection. Ovulation rates were 1.75 or 1.54. Luteolytic action on sheep of Cloprostenol "Jenapharm", a PGF2 alpha analogue, proved to be just as good as that of Oestrophan (SPOFA).

Animals↗
PubMed1991

[Estrus and ovulation synchronization in Merino meat sheep. 2. Fertility outcome after estrus and ovulation synchronization with Cloprostenol "Jenapharm" and Gonovet "Berlin-Chemie" and term-oriented artificial insemination].

49 of 102 sheep of one production herd, which had returned to oestrus once or twice within the 1985 breeding season, were treated twice in a nine-day interval with the PGF2 alpha analogue Cloprostenol "Jenapharm". 53 animals received an additional dose of 10 micrograms of Gonavet "Berlin-Chemie". A lambing rate of merely 15% was achieved by subsequent term-oriented artificial insemination. 31 sheep still in oestrus one day after term-oriented artificial insemination were served, bringing the lambing rate from synchronisation of oestrus and ovulation to 26% and the lambing result to 154%. Serving of the remaining sheep in 2 subsequent oestric cycles, on balance, yielded lambing rates and results of the remaining sheep in 2 subsequent oestric cycles, on balance, yielded lambing rates and results which were higher with significance than those recorded from untreated sheep in the same herd.

Animals↗
PubMed1991

[The treatment of severe pulmonary hypertension in newborn infants using extracorporeal membrane oxygenation or conventional measures. An interinstitutional comparison].

In a two years retrospective study we analyzed neonates from a US and a German neonatal center with pulmonary hypertension (persistent fetal circulation--PFC). The US patients were treated with Extracorporeal Membrane Oxygenation (ECMO) the german patients with conventional methods as hyperventilation, catecholamines, and vasodilators. Both groups fulfilled the classical ECMO entrance criteria: an alveolar-arterial oxygen difference greater than 610 mmHg and an oxygenation index (i.e. mean airway pressure x FiO2 x 100/paO2 of greater than 40 mmHg. We compared anamnestic and respiratory parameters with the t-test for independent groups or the chi-square test accordingly. With one patient in each group the mortality was not significantly different and the rate of meconium aspirations was the same. The APGAR score at 5 min was significantly lower in the US group, prenatal care was undertaken in significantly less US than german patients. Time intervals between delivery and important therapeutic interventions as intubation, hyperventilation, first catecholamines were not significantly different between both groups. Also worst paO2, pH, and paCO2 were not significantly different. Mechanical ventilation was more aggressive in the US group, i.e. higher intermittent-mandatory-ventilation-rate and peak inspiratory pressure. On the one hand our studies demonstrate that even patients fulfilling ECMO criteria still have a good chance with conventional treatment. On the other hand differences in APGAR scores and prenatal care might indicate that hypoxic-ischemic influences alter the US-group morbidity.

Apgar Score↗
PubMed1991

Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum infections in women. Prevalence, risks and management at a South African infertility clinic.

Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum infections not only jeopardize fertility but also pose a risk for infertility treatment and resulting pregnancies. Routine screening tests or empirical antibiotic treatment of infertile couples may be justified by the prevalence of these organisms. We studied the wives in 40 consecutive infertile couples. Monoclonal direct immunofluorescence (DIF) for C trachomatis was performed on fixed smears from endocervical swabs. M hominis and U urealyticum were isolated by inoculation of Hayflick (HF) medium, HF broth and Ureaplasma A7 agar with endocervical swabs. Using DIF, 11 (27.5%) specimens were positive, 25 (62.5%) were negative, and 4 (10.0%) were equivocal. DIF was repeated on smears from three of the last four patients; all three were positive for C trachomatis. One patient was lost to follow-up and excluded from the study. For the total 39 specimens the final results were 14 (35.9%) positive and 25 (64.1%) negative. M hominis was isolated from 3 (7.5%) endocervical swabs. None of the endocervical swabs yielded a culture positive for U urealyticum. Statistical analysis showed no correlation between the clinical history and presence of infection with any of the three organisms. The prevalence of 35.9% for C trachomatis was surprisingly high for an infertile population and, if supported by culture confirmation, justifies routine screening. The potential adverse effects of these organisms on the success rate of highly specialized infertility treatments are essentially unresolved. Since our analysis of cost effectiveness as applicable to our unit, all new infertile couples are treated empirically with lymecycline.

Adult↗
PubMed1990

Structural characterization of the human DNA topoisomerase I gene promoter.

We have isolated a genomic DNA fragment from HeLa cells containing the promoter region and the first two exons of the human gene encoding DNA topoisomerase I (hTOP1). Transcription of hTOP1 mRNA initiates at multiple sites which are clustered 247 nucleotides and 210 nucleotides upstream of the translation-initiation site of the protein coding region. The nucleotide sequence of the region preceding the transcription-initiation sites is G/C rich and contains sequence motifs which are known binding sites of the transcription factors Oct1 (octameric transcription factor 1), Sp1 and AP2 (activator protein 2). Furthermore, one cAMP-responsive element is present 50 nucleotides upstream of the transcription-initiation site nearest the 5' end. Neither TATA nor CAAT boxes were found in the promoter region of the hTOP1 gene. A 918-bp fragment containing the sequence elements described above drives the transient expression of a chloramphenicol acetyl transferase (CAT) gene sequence in transfected HeLa and 293 cells. In addition we analyzed a 10-kb fragment containing the promoter and exons 1 and 2 for regions of DNase I hypersensitivity. We detected one prominent DNase-I-hypersensitive region in the promoter close to the putative transcription-factor-binding sites and several weaker regions in intron 2.

Autoradiography↗