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Biomedical subjects

A Richter

Publications and source records attributed to A Richter.

At least 307 records · Page 17Linked to original sources

Prognosis for patients with initially suspected acute myocardial infarction in relation to presence of chest pain.

In all 4,232 patients admitted to a single hospital during a 21-month period due to initially suspected acute myocardial infarction (AMI), the prognosis and risk factor pattern were related to whether patients had chest pain or not. Symptoms other than chest pain that raised a suspicion of AMI were mainly acute heart failure, arrhythmia, and loss of consciousness. In 377 patients (9%) symptoms other than chest pain raised an initial suspicion of AMI. These patients developed a confirmed infarction during the first three days in hospital with a similar frequency (22%) as compared with patients having chest pain (22%). However, patients with "other symptoms" had a one-year mortality of 28% versus 15% for chest pain patients (p less than 0.001). Patients with "other symptoms" more often died in association with ventricular fibrillation and less often in association with cardiogenic shock as compared with chest pain patients. Among the 921 patients who developed early AMI, 64 (7%) had symptoms other than chest pain. They had a one-year mortality of 48% versus 27% for chest pain patients (p less than 0.001). We conclude that in a nonselected group of patients hospitalized due to suspected AMI, those with symptoms other than chest pain have a one-year mortality, which is nearly twice that of patients with chest pain.

Aged↗

Characterization of SAF-A, a novel nuclear DNA binding protein from HeLa cells with high affinity for nuclear matrix/scaffold attachment DNA elements.

We identified four proteins in nuclear extracts from HeLa cells which specifically bind to a scaffold attachment region (SAR) element from the human genome. Of these four proteins, SAF-A (scaffold attachment factor A), shows the highest affinity for several homologous and heterologous SAR elements from vertebrate cells. SAF-A is an abundant nuclear protein and a constituent of the nuclear matrix and scaffold. The homogeneously purified protein is a novel double stranded DNA binding protein with an apparent molecular weight of 120 kDa. SAF-A binds at multiple sites to the human SAR element; competition studies with synthetic polynucleotides indicate that these sites most probably reside in the multitude of A/T-stretches which are distributed throughout this element. In addition we show by electron microscopy that the protein forms large aggregates and mediates the formation of looped DNA structures.

Animals↗

Elastase alpha 1 proteinase inhibitor complex, granulocyte count, ratio of immature to total granulocyte count, and C-reactive protein in neonatal septicaemia.

In a prospective study elastase alpha 1-proteinase inhibitor (E alpha 1PI), polymorphonuclear (PMN) count, the immature to total neutrophil count ratio (I/T ratio), and C-reactive protein (CRP) were analysed in 74 patients (76 cases) with neonatal septicaemia at the time of initial clinical symptoms. At that early stage of the disease, 94% of the patients had abnormal values for E alpha 1PI, 71% for I/T ratio, 61% for PMN count, and only 54% for CRP. PMN count was a poor indicator of septicaemia. Neutropenia, present in 26% of all patients, was related to normal E alpha 1PI in only 4 patients. The combined use of E alpha 1 and I/T ratio was the most sensitive indicator. In all patients irrespective of causative bacteria or disease onset at least one of these parameters was elevated. In early-onset septicaemia (n = 31), normal CRP values occurred significantly more often (63%) than in late-onset sepsis (33%). Even in five of the seven fatal cases, initial CRP measurements were normal. The sensitivity of PMN count and I/T ratio did not differ significantly between early- and late-onset septicaemia. Laboratory changes observed in 18 newborns during the first 3 days of the septic episode show that the rate of pathological values for E alpha 1PI and I/T ratio was highest at the time of initial clinical symptoms and decreased on days 2 and 3. In contrast, CRP reached maximal values as late as day 2 (88% abnormal values), followed by a decrease on day 3. We conclude that the use of E alpha 1PI may improve the laboratory detection of neonatal septicaemia especially if used in combination with I/T ratio.

Bacteremia↗

Prognosis in hypertensives with acute myocardial infarction.

OBJECTIVES: A previous history of hypertension is overrepresented among patients with ischaemic heart disease. The present study aims at describing the influence of a previous history of hypertension upon the prognosis among patients hospitalized due to acute myocardial infarction. DESIGN: Patients were followed for 1 year. Mortality and morbidity are described during hospitalization and after discharge from hospital. SETTING: Sahlgrenska Hospital, serving half of the area of Gothenburg in Sweden. PATIENTS: All patients admitted to Sahlgrenska Hospital during 21 months due to acute myocardial infarction regardless of age and whether they were admitted to the coronary care unit. RESULTS: Among all patients with confirmed acute myocardial infarction (n = 917) a previous history of hypertension was reported in 324 patients. Hypertensives more frequently had a previous history of acute myocardial infarction, angina pectoris, congestive heart failure and diabetes mellitus. Their mortality during hospitalization was similar to that in normotensives. However, the total mortality during 1 year of follow-up was 35% in hypertensives and 25% for normotensives (P < 0.01), and a previous history of hypertension was an independent risk indicator for death after discharge from hospital. Place and mode of death appeared similar in normotensives and hypertensives. Reinfarction was twice as common in hypertensives as in normotensives, and a previous history of hypertension was an independent risk indicator for reinfarction. CONCLUSIONS: Among patients with acute myocardial infarction a previous history of hypertension indicates a poor prognosis, one-third of patients dying and one-quarter developing reinfarction during the first year after onset of acute myocardial infarction.

Aged↗

Prophylactic low-dose vancomycin treatment in very-low-birth-weight infants.

For the prophylaxis of septicemia with coagulase-negative staphylococci in a high-risk very-low-birth-weight population, we administered 5 mg/kg of vancomycin every 12 h. Distribution volume and half-life of vancomycin were determined. Serum peak and trough levels were obtained on day 3 of treatment. With this low-dose regimen, serum concentrations in the therapeutic range were achieved in 35 of the 45 patients. Distribution volume and half-life were 0.692 liters/kg and 7.4 h, respectively. The distribution volume was not related to the gestational age; the half-life in the group of patients with a gestational age < 30 weeks was considerably higher. The 10 small-for-gestational-age children had a significantly smaller distribution volume. The vancomycin trough levels correlated with the serum creatinine concentrations and, therefore, with the gestational age. Our study indicates that this low vancomycin dose is sufficient in very-low-birth-weight infants to achieve therapeutic serum levels, being suitable for both prophylaxis and sepsis therapy.

Creatinine↗

[Acute biliary and alcoholic pancreatitis: two different diseases?].

An analysis of 174 patients with an acute biliary or alcoholic pancreatitis who were admitted to the Surgical University Clinic Mannheim from 1986 until 1989 showed significant differences in the course of the disease and surgical treatment. 77.2% of our patients with an acute alcoholic pancreatitis were men. Mean age of all patients was 45.7 years. 72.3% of our patients had a mild pancreatitis and 27.7% a necrotising pancreatitis. In 26.8% of the patients an operation was necessary (necrosectomy, lavage of the lesser sac). In 35% of these patients occurred complications. Total lethality was 9.9% (mild pancreatitis: 0%, severe pancreatitis: 17.6% and total necrosis of the pancreas: 63.6%). 58.9% of our patients with an acute biliary pancreatitis were women. Mean age of all patients was 62.4 years. In 50% of all cases an operation was necessary (in most cases cholecystectomy and extraction of a prepapillary concrement but also necrosectomy and lavage of the lesser sac). In 17% of these patients occurred complications. Total lethality was 11.0% (mild pancreatitis: 0%, severe pancreatitis 8.3% and total necrosis: 77.7%). The conclusion is a surgical therapy depending of the cause of the pancreatitis and also a different prognosis of the disease.

Acute Disease↗

[Use of different superovulation regimes and laparoscopic studies of ovarian function in African dwarf goats].

17 African dwarf goats were treated with 4 different superovulation regimes. The results of the treatments were assessed spectroscopically and checked laparoscopically. The quantitative basis of the investigation is too small to allow statistically well-founded statements, but is indicative of distinctive trends. A proportion of 73% CL and CLA in the overall ovarian changes after treatment with 750 IE PMSG (2 days before removal of the sponge) and 125 micrograms PGF2 alpha (at the time of the sponge removal) proved an acceptable method of treating African dwarf goats as regards the requirement of labour and material as well as the superovulation effect.

Administration, Intravaginal↗

Atypical reactions to halothane in a subgroup of homozygous malignant hyperthermia(MH)-susceptible pigs: indication of a heterogenous genetic basis for the porcine syndrome.

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle. In genetically susceptible pigs, MH can be induced by volatile, halogenated anaesthetics such as halothane. Within a series of pharmacological investigations, a fulminant MH could be induced in 59 of 66 homozygous halothane-susceptible pigs by a challenge with 3% halothane for 15 minutes. The typical MH was characterized by sudden appearance of tachycardia, muscle rigidity with typical extension of the hindlimbs, increase of body temperature, acidosis-caused by rapid increase of CO2 and lactate production-, hyperkalaemia and increased activity of creatine kinase (CK) and aspartate transaminase (AST). In seven homozygous MH-susceptible pigs, this typical MH could not be induced by halothane. These animals responded with sudden appearance of bradyarrhythmia and decrease of arterial pressure. In these MH-atypical pigs (MHA) neither the typical extension of hindlimbs nor a hyperthermia occurred. Compared to a group of 6 MH-susceptible pigs with typical reactions to halothane (MHS), the biochemical alterations were significantly retarded in MHA-pigs. These atypical reactions to halothane could be the effect of decreased cardiac output. Concerning the atypical reactions, we observed a familiar predisposition in MH-susceptible pigs. Although atypical reactions were not found in a group of homozygous halothane-nonsusceptible pigs (MHN), a possible explanation for atypical reactions could be a MH-independent halothane-susceptibility of the myocardium+ in MHA-pigs. On the other side the data may indicate that a primary defect in both the skeletal muscle and also the myocardium is involved in MH. The different reactions to halothane in MH-susceptible pigs could point to a genetic heterogeneity.

Animals↗

[Sonography during the pregnancy of sheep. I. Fetometry for the determination of the stage of gestation and prediction of the time of parturition].

Transrectal and transcutaneous ultrasonography was performed on 187 pregnant Merino ewes to measure the growth of fetal parameters (fetometry) such as the diameters of the eye, braincase and trunk, the width of one rib with its intercostal space and the crown-rump-length (CRL). In the ewes, cross and longitudinal diameters of the intrauterine lumen around the embryo and fetus were determined. Trunk diameter and crown-rump-length of embryos and fetuses were sonographically determined from Day 26 and size of eyes, braincase and ribs were measured from Day 52 to 66 of gestation. Embryonic resp. fetal parameters and uterine diameters showed almost linear growth rate. Relationship between the measured parameters and days of pregnancy is described by regressions and correlation coefficients. Correlation coefficient between gestational stage and the diameter of the trunk was very narrow (r = 0.98) and between gestational stage and the crown-rump-length resp. eye diameter equalled 89% (r = 0.89). These fetal parameters are appropriate to assess gestational age and growth of ovine fetuses. It can be concluded that sonographic fetometry in the ovine can be valuable for the evaluation of fetal development, the estimation of gestational age and the prediction of parturition dates.

Animals↗

[The significance of the initial respiratory parameters in assessing the severity of ARDS in children].

In adults, the course and outcome of the acquired respiratory distress syndrome (ARDS) are closely related to the initial respiratory situation. Respiratory indices are frequently used for prognostic purposes and hence for the institution of new techniques such as extracorporeal lung support. The validity of these indices to predict the outcome in pediatric ARDS patients has not been examined as yet. We studied respiratory indices in 69 pediatric ARDS patients. METHODS. Out of 69 pediatric ARDS patients with various underlying diseases (Table 1), we chose 21 with a paO2/FiO2 ratio less than 150 mm Hg at some point to test the prognostic significance of a respiratory severity index (RSI), i.e., mean airway pressure x alveolar-arterial pO2 difference (A-aDo2)/paO2, a respiratory index (RI), i.e., A-aDO2-paO2/paO2, and other respiratory parameters (Table 2). Postsurgical patients, patients with incurable diseases, clearly non-respiratory deaths, and those treated with extracorporeal membrane oxygenation were excluded. We looked for statistical differences between survivors and nonsurvivors and correlations between ventilator days, intensive care unit (ICU) days, and hospital days and these indices. RESULTS. We did not find a significant difference between all respiratory indices tested at admission to the ICU and 24 h later between survivors and nonsurvivors (Table 3). Nonsurvivors initially had significantly higher blood pressures and lower heart rates. Both RSI and RI were significantly correlated to days on the ventilator, days in the ICU, and days in the hospital (Table 4). Initial multiorgan failure was significantly more common in nonsurvivors. CONCLUSIONS. Initial lung dysfunction as indicated by respiratory indices does not predict the outcome in pediatric ARDS. The underlying disease, hemodynamic situation, and age have to be considered in relation to the degree of lung dysfunction to determine new therapeutic strategies such as extracorporeal support.

Child↗

Histone H1 inhibits eukaryotic DNA topoisomerase I.

Histone H1 inhibits the catalytic activity of topoisomerase I in vitro. The relaxation activity of the enzyme is partially inhibited at a molar ratio of one histone H1 molecule per 40 base pairs (bp) of DNA and completely inhibited at a molar ratio of one histone H1 molecule per 10 base pairs of DNA. Increasing the amount of enzyme at a constant histone H1 to DNA ratio antagonizes the inhibition. This indicates that topoisomerase I and histone H1 compete for binding sites on the substrate DNA molecules. Consistent with this we show on the sequence level that histone H1 inhibits the cleavage reaction of topoisomerase I on linear DNA fragments.

Animals↗

Antidystonic effects of the NMDA receptor antagonists memantine, MK-801 and CGP 37849 in a mutant hamster model of paroxysmal dystonia.

The effects of competitive and noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists were evaluated in an inbred line of Syrian golden hamsters, in which sustained dystonic postures of limbs and trunk can be initiated by handling or mild environmental stimuli. In this model of paroxysmal dystonia, the noncompetitive NMDA receptor antagonists memantine and MK-801 (dizocilpine) delayed the progression of dystonic attacks in a dose-dependent fashion. The novel competitive NMDA receptor antagonist CGP 37849 (DL-[E]-2-amino-4-methyl-5-phosphono-3-pentenoic acid) was more effective than memantine and MK-801, because it retarded not only the progression but also reduced the severity of the dystonic movements. All compounds exhibited antidystonic effects at doses which did not cause marked ataxia or sedation. The data indicate that NMDA receptor antagonists might be interesting candidates for treatment of dystonia.

2-Amino-5-phosphonovalerate↗

DNA topoisomerase I cleavage sites in DNA and in nucleoprotein complexes.

The intracellular substrate for eukaryotic DNA topoisomerases is chromatin rather than protein-free DNA. Yet, little is known about the action of topoisomerases on chromatin-associated DNA. We have analyzed to what extent the organization of DNA in chromatin influences the accessibility of DNA molecules for topoisomerase I cleavage in vitro. Using potassium dodecyl sulfate precipitation (Trask et al., 1984), we found that DNA in chromatin is cleaved by the enzyme with somewhat reduced efficiency compared to protein-free DNA. Furthermore, using native SV40 chromatin and mononucleosomes assembled in vitro, we show that DNA bound to histone octamer complexes is cleaved by topoisomerase I and that the cleavage sites as well as their overall distribution are identical in histone-bound and in protein-free DNA molecules.

Base Sequence↗

Early prediction of acute myocardial infarction from clinical history, examination and electrocardiogram in the emergency room.

The possibility of early prediction of acute myocardial infarction (AMI) was assessed in 7,157 consecutive patients coming to our emergency room during a 21-month period with chest pain or other symptoms suggestive of AMI. Of these patients 921 developed an AMI during the first 3 days in the hospital. Of the 4,690 patients admitted to hospital, 1,576 (34%) had a normal admission electrocardiogram, and 90 of these (6%) developed AMI. Of 1,964 patients with an abnormal electrocardiogram without signs of acute ischemia (42% of those admitted), 268 (14%) developed AMI, and 563 (51%) of 1,109 patients with acute ischemia on the electrocardiogram (24%) developed AMI. All patients were prospectively classified in the emergency room on the basis of history, clinical examination and electrocardiogram into 1 of 4 categories, according to the initial degree of suspicion of AMI. Of 279 admitted patients judged to have an obvious AMI (6% of the 4,690), 245 (88%) actually developed AMI; of 1,426 with a strong suspicion of AMI (30%), 478 (34%) developed one; of 2,519 with a vague suspicion of AMI (54%), 192 (8%) developed one; and of 466 with no suspicion of AMI (10%), 6 (1%) developed one. Thus, only a low percentage of the patients with a normal initial electrocardiogram or a vague initial suspicion of AMI developed a confirmed AMI.

Electrocardiography↗