Search PubMed⌕ Search

Biomedical subjects

H Hofmann

Publications and source records attributed to H Hofmann.

At least 163 records · Page 9Linked to original sources
PubMed1985

[Diagnosis and therapy of fetal kidney and urinary tract malformations].

Of 23 patients with abnormal prenatal sonographic findings 17 also showed malformations of the kidneys and urinary tract in the postpartal period. Although even minor abnormalities could be detected by antenatal ultrasound, the identification of the abnormal findings was not possible in every case. Diagnostic problems arose in 8 foetuses showing mild dilatation of the collecting system, since it was not possible to distinguish between functional dilatation and dilatation from vesicoureteral reflux or minimal ureteral obstruction. Difficulties in identification of large malformations also occurred in 3 other patients, if the first sonographic examination was performed in a late stage of pregnancy, so that no follow-up of the sonographic picture was possible. In one of these children a huge right-sided multicystic kidney resulted in compression of the contralateral ureter with hydronephrosis, damaging the other kidney. Early delivery should, therefore, be considered in all children showing large cystic abdominal masses and no identifiable normal kidney, so that adequate obstetric treatment of these patients can be initiated in time.

Female↗
PubMed1985

[Blood sugar and lipid metabolism parameters in diabetic retinopathy].

In Type I and Type II diabetics hemoglobin A1c, triglycerides, total cholesterol, HDL cholesterol, LDL cholesterol, and the apolipoproteins A I and B were determined and compared with a control group. In diabetics the HbA1c values were significantly higher, but were found to fluctuate considerably during several years of observation. Some parameters of lipid metabolism also differed significantly from those in the control group and in most of the diabetics one or more parameters of lipid metabolisms were in the pathologic range. However, no correlation was found between the parameters of blood glucose and lipid metabolism on the one hand and diabetic retinopathy on the other.

Apolipoprotein A-I↗
PubMed1985

Interaction between a normoxic and a hypoxic region of guinea pig and ferret papillary muscles.

Papillary muscles were mounted in a three-compartment bath. The tip of the muscle was exposed to hypoxic and glucose-free solution. The other parts of the preparation were superfused with Tyrode's solution, building a free-flow border between hypoxic and normoxic superfusates. The normoxic part of the bath was subdivided by a rubber membrane so that current pulses could be applied between segments of the preparation. Signs of electrotonic interaction between normoxic and hypoxic parts were observed a few minutes after the onset of hypoxia. Transmembrane action potentials in the normoxic part retained their plateau, but progressively shortened. Those in the hypoxic tip showed an early phase of rapid repolarization followed by a plateau phase near the resting potential. Terminal repolarization in the two parts coincided for many minutes. After 35 minutes, fast propagated activity ceased in the tip and was replaced first by conducted slow responses, then by decremental conduction. At 50 minutes, cells near the borderline had resting potentials of either -76 +/- 7 mV (SD, n = 9) in normoxic tissue or -16 +/- 3 mV (SD, n = 9) in hypoxic tissue. Concurrently, subthreshold potentials no longer appeared to spread into the tip. Unipolar electrograms remained diphasic over the normoxic part but lost their negative deflection near the borderline, implying the absence of axial current flow into the hypoxic part. Furthermore, electrotonic potentials generated by current flow across the rubber membrane did not spread beyond a line of demarcation. Reduced nicotinamide adenine dinucleotide fluorescence increased in the hypoxic part, and appeared to correlate with the development of electrical decoupling.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1985

[Detection of the gonococcal antigen with an enzyme immunoassay (Gonozyme). Results of the original and modified test procedure].

Urogenital specimens of 2,485 patients were examined by an enzymeimmunoassay for the detection of Neisseria gonorrhoeae antigen (Gonozyme, Abbott). The results of the original test (Gonozyme A) and a modified version (Gonozyme B) were compared to bacterial culture. Three different groups were examined by Gonozyme A: 526 men and 464 women from the clinic for sexually transmitted diseases (STD) and 548 registered prostitutes. Sensitivity in men was 98%, in women from the STD clinic 89%, and in prostitutes 81%. Specificity in men was 99.5%, in women from the STD clinic 94%, and in prostitutes 88%. One of the reasons for the decreased specificity in women could be cross reacting bacteria from the genital secretions of the women. The assay was modified by optimizing the antigonococcal antibody and increased incubation times. These modifications improved the specificity of Gonozyme B by reducing the number of cross reactions with other bacterial antigens. Four different groups were examined by Gonozyme B: 261 men and 220 women from the STD clinic, 121 women from an infertility clinic, and 345 registered prostitutes. Sensitivity in men was 100%, in women from the infertility clinic 100%, in women from the STD clinic 94%, and in prostitutes 77%. Specificity in men was 99%, in women from the infertility clinic 100%, in women from the STD clinic 99%, and in prostitutes 96.5%. Analysis of the Gonozyme-positive/culture-negative test results suggested that most patients (85%) did not have gonorrhoea. In 15% of these specimens it is possible that patients had pretreated gonorrhoea which was only detected by Gonozyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Bacterial↗
PubMed1985

[Kaposi sarcoma in acquired immune deficiency syndrome (AIDS). I: Clinical findings and laboratory diagnosis].

In addition to the classical type of Kaposi's sarcoma, a new, aggressive and prognostically ominous variant occurs since 1980: the AIDS-associated Kaposi's sarcoma. This aggressive variant is associated with viral infection by the lymphotropic retrovirus HTLV-III, identical to LAV. In the U.S.A. and in Europe, this virus is transmitted mainly by homosexual contact, whereas in Central Africa the characteristic mode of transmission is heterosexual promiscuity. The authors present for the benefit of the ENT-specialist, case-reports of an American/European and of an African AIDS-associated Kaposi's sarcoma of the palate illustrating the major symptoms of generalized lymphadenopathy, opportunistic infections, and the relevant immunological and serological features.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Amniotic fluid glucose values in normal and abnormal pregnancies.

Glucose values were determined in 102 urine samples of newborn infants and in 2295 amniotic fluid (AF) samples of women between the 14th and 42nd week of pregnancy. One thousand, six hundred fifty-five of the AF samples derived from normal pregnancies, 50 from pregnancies with fetal malformations, 115 from cases of hydramnios, 246 from pregnant women with an abnormal oral glucose tolerance test, and 230 from insulin-dependent diabetics. Mean AF glucose concentration rises slightly between the 14th and 17th week of pregnancy, decreasing from 46 to about 16 mg% at the end of pregnancy. In cases of fetal malformations, 68% of the glucose levels was below the tenth percentile of normal values. Hydramnios showed no deviation from normal values. In patients with abnormal glucose tolerance, AF glucose increased by a total of 42% and by 67% in fetal hyperinsulinism. Insulin-dependent diabetics had glucose values elevated by a total of 77% and by 106% in fetal hyperinsulinism. The AF glucose profile reflects the level of maternal blood glucose that is transported to the fetus and excreted in the fetal urine as a major source of glucose in AF.

Amniotic Fluid↗
PubMed1984

[Early prognosis of the course of hepatitis B using radioimmunoassay of HBA/IgM complexes].

By other authors complexes of HBsAg and nonspecific gammaglobulin of the IgM class were found in the serum in the early stages of hepatitis B. These complexes were detected by radioimmunoassay. They persisted in chronic hepatitis, but disappeared from the serum within one month in acute cases. Our own data also confirm these findings. From our figures it can be calculated that the prognosis of acute hepatitis in any one patient can be stated with a probability of 98.8% as early as 4 weeks after onset of the disease. Two weeks later a chronic course can be predicted with a probability of 82%. HBsAg/IgM-complexes occur almost exclusively in sera positive for HBsAg. Their disappearance, however, is independent of the presence of HBeAg, as well as of the amount of HBsAg. They represent a new marker which is recognizable at an early stage of infection and gives a reliable prognosis of the course of hepatitis B.

Antigen-Antibody Complex↗
PubMed1984

[Experiences with vaccination against hepatitis B].

In a field study conducted with the Hepatitis B vaccine HB-Vax 375 persons were vaccinated and the sera were assayed for the formation of HBs antibodies 1 to 3 months after completing the three-dose schedule. Seroconversion was demonstrated in 94.7% of the subjects. Immune response was poorer after 40 years of age as compared with younger age groups. The vaccine was very well tolerated and induced hardly any side effects. 49 persons who had received 3 of the 4 doses suggested for vaccination with Hevac B responded in 86% of cases with the formation of antibodies. Patients undergoing dialysis developed antibodies in 48% of cases after the third dose and in 77% after the fourth dose, the seroconversion rate thus being considerably lower than in healthy persons.

Antibody Formation↗
PubMed1984

Localization of flexible sites in thread-like molecules from electron micrographs. Comparison of interstitial, basement membrane and intima collagens.

A computer method for detecting kinks and flexible sites in thread-like molecules was developed. The method is based on the determination of the local curvature along the digitized electron micrographs of the molecules. The root-mean-square curvature provided a measure for the local flexibility, which is related to the persistence length. The influence of various error sources was assessed using computer-simulated thread molecules. "Flexibility profiles" showing the variation of flexibility along molecules were calculated for interstitial, basement membrane and intima collagens. Approximately uniform stiffness corresponding to a persistence length of 60 nm was found for the triple helices of interstitial and monomeric intima collagen. A highly flexible site in interstitial collagen could be assigned to a non-triple helical segment in the sequence surrounding the linkage site of the N-terminal propeptide. A flexible site in the triple helix of collagen I corresponds to a segment of the sequence lacking proline residues. Flexibility varies strongly along the collagen IV molecule. This is consistent with the fact that a series of non-triple helical interruptions have already been found in the not yet completed amino acid sequence of basement membrane collagen. Most of the detected flexible sites allow random bending about the mean zero, but in one case, at the border of the 7S domain of polymeric collagen IV, a flexible site with a preferential angle of 40 degrees was found.

Animals↗
PubMed1984

[Incidence of genital chlamydia and mycoplasma infections in women].

An investigation was carried out in 240 women to determine the prevalence of Chlamydia trachomatis and Mykoplasms in the genital tract. Three groups of women were compared: 80 prostitutes, 80 STD-patients and 80 dermatological patients without genital complaints. In the group of the prostitutes Chlamydia trachomatis was detected in 25% and Mycoplasms in 60%. STD-patients harbored Chlamydia trachomatis in 21% and Mycoplasms in 45%. In the group of dermatological patients Chlamydia trachomatis was isolated only in 3% and Mycoplasms in 33%.

Chlamydia Infections↗
PubMed1984

Adhesion, spreading and growth of animal cells on the surface of glass ceramic Ap40--a contribution to the cell compatibility of dental permanent hard tissue implants.

Cells of different cell lines on the surface of glass ceramic Ap40 responded in the manner of reversible vacuolization in the cytoplasm. Whereas the eluate of bulk glass ceramic did not produce toxic effect on cell populations in vitro, the eluate of pulverized glass ceramic Ap40 caused a toxic reaction, the effect being dependent on concentration and incubation time. Although cell attachment, spreading and proliferation of fibroblast-like and epithel-like cells on glass ceramic surfaces are delayed when compared to glass and polystyrene the cells are adhering to a confluent monolayer.

Animals↗
PubMed1984

[Lipid metabolism disorders in patients with retinal artery occlusions].

Triglycerides, cholesterol, HDL-cholesterol, LDL-cholesterol, the HDL-cholesterol/LDL-cholesterol and cholesterol/HDL-cholesterol ratio, the apolipoproteins A and B, and the ratio apo A/apo B were determined in patients with occlusions of retinal arteries and compared with a control group. The patients showed higher levels of triglycerides, cholesterol, LDL-cholesterol, apo B and the ratio cholesterol/HDL-cholesterol and a decrease in HDL-cholesterol and the two ratios HDL-cholesterol/LDL-cholesterol and apo A/apo B, indicating that disturbances in lipid metabolism may be a risk factor in the development of occlusions of the retinal arteries.

Apolipoproteins↗
PubMed1984

[HbA1 and HbA1c determination in ophthalmology. New parameters for monitoring metabolism in diabetics].

Determination of glycosylated hemoglobins HbA1 or HbA1c by column chromatography is used for long-term glucose control. In the study reported here the authors compared the advantages and disadvantages of this new method and tried to show the importance of these determinations for patients with eye diseases. In a control group (blood glucose less than 120 mg/dl) HbA1-values of 6.5 +/- 1.2% and HbA1c-values of 4.4 +/- 0.5% were found. Well-controlled diabetics (blood glucose 80-180 mg/dl) had an HbA1 of 8.1 +/- 1.6% and an HbA1c of 5.8 +/- 1.1%, while diabetics with poor control (blood glucose 160-420 mg/dl) had an HbA1 of 10.6 +/- 2.1% and an HbA1c of 7.7 +/- 1.7%. HbA1 and HbA1c, respectively, should be measured in addition to blood glucose determination and oral glucose tolerance test.

Chromatography↗
PubMed1984

Conformational transitions in viroids and virusoids: comparison of results from energy minimization algorithm and from experimental data.

Viroids are single-stranded circular RNA molecules of 240 to 400 nucleotides which are pathogens of certain higher plants and replicate autonomously in the host cell. Virusoids are similar to viroids in respect to size and circularity but replicate only as genomic part of a plant virus. Their structure and structural transitions have been investigated by thermo-dynamic, kinetic and hydrodynamic methods. The special features of the sequences of these RNAs, which are the basis for their secondary structures and structural flexibility, are investigated with theoretical methods. A set of thermodynamic parameters for helix growth and loop formation is selected from the literature to calculate secondary structures and structural transitions of single-stranded RNAs. Appropriate modifications of the chosen parameter set are discussed. For calculations we used either Tinoco-plots and the model of "cooperative helices" or the Zuker-program based on the exact algorithm of Nussinov et al, or both. Calculations were done for viroids and virusoids. As both are single-stranded, circular RNAs we had to modify the Zuker-program as described in the appendix. Calculations are done for different viroids, i.e. potato spindle tuber, citrus exocortis, chrysanthemum stunt, coconut cadang-cadang, and avocado sunblotch, and for two virusoids, i.e. the circular RNAs of Solanum nodiflorum mottle virus, and velvet tobacco mottle virus. For viroids the calculations confirm our earlier theoretical and experimental results about the extended native structure and the highly cooperative transition into a branched structure. Virusoids show less base pairing, branching in the native secondary structure, and only low cooperativity during denaturation. They resemble more closely the properties of random sequences with length, G:C content, and circularity as in viroids but statistical sequences. The comparison of viroids, virusoids, and circular RNA or random sequences confirms the uniqueness of viroid structure.

Algorithms↗
PubMed1984

Investigation of intrapartum clearance of the upper airway in the presence of meconium contaminated amniotic fluid using an animal model.

In order to define as effective a procedure as possible for the intra- and post-partum clearance of the upper airways of meconium contaminated infants, three methods of suction clearance, nasal, oral and combined nasal and oral, were carried out on each of five kittens aged between 17 to 19 weeks. There was an interval of at least one week between each investigation. The animals were anaesthetized with ketamine intramuscularly. The pressure changes during delivery were simulated using a compressed blood pressure cuff around the kittens thorax. During the first minute of thoracic compression Tc 99 labeled synthetic sputum was introduced into both the oro- and nasopharynx, then during the 2nd minute the instilled fluid was removed using a conventional extractor with mucus trap. Solely oral or solely nasal routes were used, suction was carried out for 60 secs, whereas when the combined technique was applied the oral and nasal cavities were cleared for only 30 secs each. At the end at the 2nd minute thoracic compression was released and a deep inspiration occurred. After five minutes the radioactivity remaining after suction was documented using a gamma-camera. We attempted to answer the following questions: How much mucus could be extracted with each different method, and where the remaining amount was later distributed? Nasal suction alone was found to be inefficient; using this route an average of 13% (only an eight of the amount instilled) could be removed. Oral suction led to the recovery of an average of 52% of the material instilled, the combined technique much as 56%. After re-establishment of spontaneous respiration, it could be clearly seen that, independent of the efficacy of the technique used, the majority of the remaining radioactivity (55 relative percent) is localized in the head and neck area. Absolute values are 45% for nasal suction, 26% for oral, and 24% for the combined oro-nasal route. The other part of the remaining radioactivity was found in the lung or in the stomach. It must be pointed out that the aspirate need not be disturbed in both of the parts, both the stomach and the lungs can be solely involved. Five minutes after spontaneous respiration had been resumed the lungs revealed only a centrally distributed radioactivity. This corresponds anatomically to the trachea and major bronchi. The peripheral area of the lungs was free of aspirate at this point in time.(ABSTRACT TRUNCATED AT 400 WORDS)

Airway Obstruction↗