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M Hartung

Publications and source records attributed to M Hartung.

At least 37 records · Page 2Linked to original sources
PubMed1991

Crossed immunoelectrophoresis applied to representative strains from 11 different Pasteurella species under taxonomic aspects.

Crossed immunoelectrophoresis evaluated on a numerical basis revealed a close antigenic relationship between species of the genus Pasteurella. By cluster analysis, 4 groups on similarity levels between 87% and 72% S could be separated which were connected by a minimum level of 69.5% S. One subgroup included all biovars or subspecies consisting of strains with mucoid growth. Another feature governing the antigenic relationship seemed to be the host range of Pasteurella species. Despite a considerable number of cross-reacting antigens, representative strains of the genera Haemophilus and Actinobacillus were clearly separated from Pasteurella. Similarly, "Pasteurella" haemolytica and Taxon 16 strains tested did not belong to this genus. An Escherichia coli strain showed a higher number of cross-reacting antigens, confirming known antigenic relationship among Gram-negative bacterial species.

Animals↗
PubMed1991

Transcribed and nontranscribed parts of the human ribosomal gene repeat show a similar pattern of distribution in nucleoli.

The distribution pattern of the transcribed and nontranscribed parts of human ribosomal RNA genes were visualized simultaneously in the same cells by nonautoradiographic in situ hybridization. DNA probes labeled with either digoxigenin or biotin were detected in the same cells by different fluorescence systems. The signals from both the transcribed and nontranscribed parts showed a similar distribution pattern. This finding is not compatible with the conclusion, suggested by earlier studies, that the transcribed and nontranscribed parts of the rRNA genes are located at different sites within the nucleoli or in different nucleolar components.

Cell Nucleolus↗
PubMed1991

Yersinia in effluents from the food-processing industry.

Yersinia enterocolitica and Yersinia pseudotuberculosis are current sources of pathogenic strains in humans and animals. Yersiniae infections occur throughout the world, but are most prevalent in regions with moderate and subtropical climates. In Australia, Central Europe and North America, cases of human infections with Yersinia enterocolitica now rank in third place. The food-processing industry may influence the epidemiological situation in different ways. Effluents which contaminate the environment may originate from slaughterhouses; e.g. from sewage contaminated with faeces from the lairage or contaminated effluents from the actual slaughter areas. The carcasses may serve as carriers of the organisms to the food-processing plants where they eventually contaminate the processed foods. Rodents and pests may also be carriers. Pathogenic Y. enterocolitica and Y. pseudotuberculosis strains mainly occur in swine and pork. The ability to multiply under refrigeration and in vacuum-packaged products means that pathogenic Y. enterocolitica can cause foodborne diseases. If a plant harbours any pathogenic Yersiniae, transfer of the contaminant to the sewage is possible. Although pathogenic Yersiniae from infected animals can survive in sewage and in surface waters, the role of properly treated sewage in the transmission of yersiniosis seems to be of minor importance. If the recommendations for modern slaughter techniques are properly followed, the spread of pathogens in the slaughterhouses and, subsequently, into other food-processing plants can be minimised.

Animals↗
PubMed1990

Sequential changes in the nucleoli of human spermatogonia with special reference to rDNA location and transcription.

The nucleoli of human spermatogonia were studied using electron microscopy, silver staining, radioautography and in situ hybridization. In all types of A spermatogonia, nucleoli were consistently located at the periphery of the nucleus and contained a single fibrillar center associated with the nuclear envelope. In B spermatogonia, nucleoli were centrally located in the nuclei and showed several fibrillar centers or were found to disintegrate. Nucleolar morphology was found to be a good, though not an unequivocal indicator of spermatogonial type. The observed changes in nucleolar morphology reflect the differentiation of spermatogonia: the nucleolar disintegration seen in B spermatogonia corresponds to a pre-leptotene cessation of rDNA transcription. In radioautographs following 3H-uridine uptake, the label was consistently found over the dense fibrillar component, except in the B spermatogonia with disintegrating nucleoli, where no uptake could be detected. In situ hybridization demonstrated that the distribution of rDNA did not correspond to the site of the fibrillar center but to the dense fibrillar component. Compared with radioautographs, this finding clearly established that transcribed units of rDNA were located in the dense fibrillar component. Silver staining was strongly positive in fibrillar centers and in the dense fibrillar component. In Ap spermatogonia the silver deposit was often localized at the edge of the fibrillar threads. The relationships between silver-stained proteins and transcribed and nontranscribed portions of ribosomal genes are reevaluated.

Autoradiography↗
PubMed1990

Suppression of a hind limb flexion withdrawal reflex by microinjection of glutamate or morphine into the periaqueductal gray in the rat.

Microinjection into the midbrain periaqueductal gray (PAG) or lateral reticular formation (LRF) of the neuronal excitant glutamate produces analgesia, and suppresses the responses of a fraction of spinal dorsal horn neurons to noxious heat applied to ventral hind paw skin. Microinjection of morphine into the PAG also produces analgesia, but has been reported to frequently facilitate, as well as to suppress or have no effect, on nociceptive spinal neurons. In anesthetized rats, we tested whether (a) glutamate microinjections into PAG or LRF, and (b) morphine microinjections into PAG, affected the isometric force of hind limb withdrawal elicited by the same noxious heat stimuli on the hind paw as used in single-unit studies of dorsal horn neurons. Glutamate (0.5 M; 0.1-0.5 microliter) microinjected at 9/12 PAG and 8/10 LRF sites suppressed the reflex, and had no effect or facilitated the reflex from the remaining sites. Morphine (5 micrograms in 0.5 microliter) microinjected at each of 10 PAG sites suppressed the reflex in a naloxone-reversible manner. Suppression usually began shortly after morphine, peaked at 20-40 min, and lasted greater than 60 min. The integrated flexion reflex thus appears to be more susceptible to chemical midbrain stimulation under these experimental conditions, compared to previous studies of single dorsal horn neurons.

Animals↗
PubMed1989

The excitation of cutaneous nerve endings in a neuroma by capsaicin.

Spontaneous electrophysiological activity and excitation by capsaicin of regenerating sensory fibers has been studied using 1 to 20-week-old neuromas induced in rats by ligating and transecting the saphenous nerve. Overall, spontaneous activity occurred in 12% of fibers, and capsaicin at concentrations up to 1.0 microM excited 3.8% of all the A delta-plus C-fibers examined. There was a slight increase in the incidence of spontaneous activity, but not excitation by capsaicin, with increasing age of the neuromas. The responses to capsaicin were similar to those seen with normal saphenous nerve endings, including bursting discharges and desensitization with repeated applications. The results are considered in the context of the requirements for reexpression of normal sensory capacities on regenerating sensory nerve endings.

Action Potentials↗
PubMed1989

Ribosomal DNA is located and transcribed in the dense fibrillar component of human Sertoli cell nucleoli.

The distribution of rDNA and the uptake of tritiated uridine was investigated in nucleoli of human Sertoli cells. The nucleolar components in these cells are spatially arranged in a highly ordered and invariable way and can be recognized in both light and electron microscopy. The pattern of distribution of rDNA and the pattern of uridine uptake in these nucleoli correspond to the distribution of the dense fibrillar component but cannot be correlated to the shape and size of the fibrillar centers in these cells. It therefore can be concluded that the dense fibrillar component, and not the fibrillar centers, is the site of rDNA location and transcription in nucleoli of human Sertoli cells.

Autoradiography↗
PubMed1989

[Malignant diseases of the inner nose--epidemiology and occupational medicine aspects].

Squamous cell carcinomas are the most frequent malignancies of the inner nose, followed by adenocarcinomas, adenoid cystic carcinomas, and other malignant neoplasms. Carcinomas of the nose can be recognized as occupational diseases if there has been a professional exposition to ionizing rays, certain arsenic compounds, hexavalent chrome compounds, nickel, oak or beech wood dust. The sources of danger relevant in industrial medicine are indicated. At present, adenocarcinomas induced by dust of wood are of special significance: 16 out of 22 carcinomas of the nose recognized as occupational diseases between 1978 and 1986 are due to oak and beech wood dust.

Adenocarcinoma↗
PubMed1988

Yq deletion and failure of spermatogenesis.

The spermatogenesis of a sterile male carrying a Y long arm deletion was analyzed by meiotic techniques and by light and electron microscopy on testicular biopsies. R-, Q- and C- banding techniques have shown that the Y long arm deletion included the entire heterochromatin and a part of the euchromatic region, with breakpoint between q11.21 and q11.23. The seminiferous tubules showed a sharp decrease in spermatogonia, degenerative phenomena in their nuclei and a spermatogenic block. Abnormal meiotic aspects were observed: pairing failure with atypical diakinesis configurations. These findings confirm the presence of spermatogenesis controlling factors on the distal euchromatic region of the Y long arm.

Adult↗
PubMed1987

Nucleolus, nucleolar chromosomes, and nucleolus-associated chromatin from early diplotene to dictyotene in the human oocyte.

The shape, relationships, relative DNA content, and nucleolar activity of the short arm of acrocentric bivalents were studied in human oocytes from early diplotene to dictyotene. At the beginning of diplotene, the short arms of the previously paired chromosomes were again separated and displayed the same morphological features as in mitotic prophase chromosomes. They were connected only with the nucleolus. In situ hybridization and silver staining showed that the nucleolar organizer regions (NORs) were located in the peripheral region of the nucleolus. Tritiated-uridine incorporation was active. At birth, the relationships of the acrocentric short arms showed increasing complexity. The chromosomes ended in nucleolus-associated chromatin blocks of irregular shape, containing large quantities of DNA as demonstrated by intense binding of 3H-actinomycin D. The number of chromosomes converging on these chromatin blocks exceeded the number of acrocentrics, suggesting that heterochromatic regions of other chromosomes were associated with the short arm of acrocentrics. In the electron microscope, the NORs were represented by fibrillar centers located on the periphery of the nucleolus and consistently connected with the blocks of dense chromatin. These relationships remained unchanged in the primordial oocyte in the adult ovary. Persistence of 3H-uridine uptake showed that the oocyte was not at a "resting" stage. The possible cytogenetic consequences of these observations are discussed.

Cell Nucleolus↗
PubMed1987

Examination of 20 Bacillus species by crossed immunoelectrophoresis under taxonomic aspects.

In order to examine the efficiency of crossed immunoelectrophoresis (CIE) for the differentiation of species and for the determination of taxonomic relationships within the genus Bacillus, an investigation including strains of 20 species was performed. Ultrasonic extracts (USE) of sporefree-grown vegetative cells were used. With rabbit antisera against USE of type strains, the CIE was accomplished in homologous and heterologous combinations. USE's of additional strains were included into this investigation. In order to evaluate the immunoelectropherograms, the number of precipitates was counted. A mean of 103 precipitates was found in homologous reactions. With few exceptions, heterologous combinations showed less similarity in the number of antigens. Because of their high cross-reactions, the following species could not be differentiated: B. subtilis from B. amyloliquefaciens and strains of B. coagulans, furthermore, B. cereus from B. thuringiensis. The different species revealed lower numbers of precipitates with decreasing taxonomic relationships in heterologous combinations. This observation was used to classify the investigated species by a 'position-frequency analysis' (PFA). After sorting the matrix of precipitate numbers in the ascertained optimal sequence of species, a cluster analysis was carried out. The phenogram showed 6 (respectively 8) group clusters. The members of the morphologic group I (Smith et al., 1952) was found only in group cluster 2. The phenogram was partly in agreement with phenograms based on other characteristics, e.g. DNA hybridization.

Bacillus↗
PubMed1987

Represent the batches 2 of strain NCTC 3991 and NCTC 3992 B. coagulans?

In a previous publication (M. Hartung and E. Hellmann: Examination of 20 Bacillus Species by Crossed Immunoelectrophoresis under Taxonomic Aspects, Zbl. Bakt. Hyg. A 263 (1987) 509-524) we came to the conclusion that the species B. subtilis and B. coagulans were closely related. This statement has to be revised: The antigenic relationship is low. Further investigations have shown that all three B. coagulans-strains, although originating from different sources, were overgrown by B. subtilis. The same fact may have caused errors in other publications (e.g. Parry et al.: A Colour Atlas of Bacillus Species, Wolfe Medical Publications Ltd., London, 1983.

Bacillus↗
PubMed1987

[Effect and side effects of oral morphine, lormetazepam and placebos as premedication].

In 60 patients undergoing a curettage in thiopentone induced inhalation anaesthesia with enflurane and N2O/O2 = 2:1, the effects of oral premedication (2 h before anaesthesia) with 30 mg morphine (MST 30) (n = 21), 1 mg lormetazepam (Noctamid) (n = 19) and placebo (n = 21) on psychological (anxiety, depression and asthenia), physiological (blood pressure, heart and respiratory rate) and pain parameters (visual analogue scale, analgesic consumption) were investigated. The study design was single blind, randomized. Before premedication the three groups did not differ in one parameter and so were comparable. MST 30 had a significantly better anxiolytic, Lormetazepam a significantly better antidepressive effect than the compared substance. There were no differences in blood pressure and heart rate. In contrast to lormetazepam and placebo after MST 30 there was no increase in the respiratory rate which can be explained by the anxiolytic stress reducing effect. There was no difference in peri- and intraoperative pain parameters, probably due to the type of surgery. Nausea and vomiting occurred more frequently after MST 30, but there was no significance. A higher rate was probably prevented by the application of transdermal scopolamine the day before surgery. The indication of analgesics (opiates) for premedication is discussed taking the controversy into account. The results of this study show that oral morphine (MST 30) has an anxiolytic effect, one of the most important effects a premedication should have. Further studies should investigate in which types of surgery the analgesic effect of MST 30 is peri- and intraoperatively relevant, so that advantages compared to e.g. Flunitrazepam, Midazolam or Lormetazepam in a higher dosage could be expected.

Administration, Oral↗
PubMed1987

[Midazolam and pethidine/promethazine for intramuscular premedication].

The main reason for premedication is the reduction of preoperative stress. Despite the proven fact that benzodiazepines best reduce preoperative stress, combinations of opioids and neuroleptic drugs are preferred for premedication by many on reviewing the journal Der Anaesthesist. This double-blind study was performed to investigate midazolam and meperidine/promethazine for intramuscular premedication. Method. 60 patients undergoing minor gynecological surgery were randomly assigned to receive either 5-7.5 mg midazolam or 50-75 mg meperidine and 25-50 mg promethazine intramuscularly 30-90 min before surgery. Anxiety, depression, and asthenia were assessed by the patient before and after premedication but before induction of anesthesia using visual analogue scales and a nominal scale. Sedation was assessed by an observer. Heart rate and blood pressure were the physiological stress parameters. Parameters of acceptance and side effects were registered perioperatively. Results. Midazolam had a significantly better anxiolytic and antidepressive effect. There were no differences in the other parameters except for adverse effects. Meperidine/promethazine produced significantly more side-effects than midazolam. The parameters of acceptance assessed the day after surgery were comparable. Conclusions. We conclude from these results that anesthesiologists still premedicate with meperidine/promethazine because the patients accept this premedication very well when asked the day after surgery. Nevertheless, premedication with midazolam provides significantly better anxiolytic and antidepressive effects with significantly less side-effects. Therefore, midazolam should be preferred to meperidine/promethazine for intramuscular premedication.

Adolescent↗
PubMed1986

Random acrocentric bivalent associations in human pachytene spermatocytes. Molecular implications in the occurrence of Robertsonian translocations.

Acrocentric bivalent associations were studied in 232 human male germ cells at pachytene in order to understand better the preferential involvement of chromosomes 13, 14, and 21 in Robertsonian translocations. The tendency of each acrocentric bivalent to associate with another was not correlated with NOR activity, as measured by silver staining. Good agreement was noticed between their ability to associate and the amount of satellite DNA in human acrocentric chromosomes. The distribution of two-by-two acrocentric bivalent associations was random. In order to reconcile this result with the nonrandom distribution of Robertsonian translocations, a molecular hypothesis is proposed. The model is based on homology of recombinational sites, interspersed at regular interval in satellite DNA, which could increase the probability of accidental unequal crossing-over between two specific acrocentric chromosomes.

Aged↗