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Biomedical subjects

G Mehlhorn

Publications and source records attributed to G Mehlhorn.

At least 19 recordsLinked to original sources
PubMed2006

Management and course of histologically verified cervical carcinoma in situ during pregnancy.

BACKGROUND: To study the rate of regression and progression into invasive disease of patients with histologically proven carcinoma in situ of the uterine cervix during pregnancy. METHODS: Prospective observation of all pregnant women with biopsy-proven carcinoma in situ of the uterine cervix, gained by colposcopic guided biopsy from 1996 to 2004 and correlation with the route of delivery and cytologic and histologic postpartum findings. RESULTS: Eighty-three patients with histologically verified carcinoma in situ during pregnancy were treated conservatively. Two patients were lost to follow-up, one patient had an abortion, and three are still pregnant. The study population of 77 patients were followed for a median of 140 days before delivery. Postpartum regression rate was 34.2%, two patients had a diagnosis of microinvasive cervical cancer on the postpartum cone biopsy, and persistent carcinoma in situ was found postpartum in 63.1% of patients. No difference was seen for the route of delivery. Both patients with microinvasive carcinoma were delivered by primary cesarean section and are disease-free after 24 and 38 months, respectively. CONCLUSIONS: We recommend conservative management for women with carcinoma in situ of the uterine cervix. We found no difference for the route of delivery regarding postpartum regression and recommend a postpartum evaluation after the puerperium. Colposcopic guided biopsy should rule out an invasive process during pregnancy. Cesarean section as the mode of delivery should be considered, if invasion is suspected.

Adolescent↗
PubMed2003

Efficacy and safety of inhaled recombinant interleukin-2 in high-risk renal cell cancer patients compared with systemic interleukin-2: an outcome study.

Systemic IL-2 is an effective treatment for low to intermediate risk mRCC patients, its efficacy is marginal in high-risk cases. Therefore, other treatment approaches are required for this population. Ninety-four high-risk patients with RCC and pulmonary metastases were treated with inhaled plus concomitant low-dose subcutaneous rhIL-2. Clinical response, survival and safety were compared with those from IL-2 given systemically at the registered dose and schedule in 103 comparable historical controls. In the rhIL-2 INH group, treatment consisted of 6.5 MIU rhIL-2 nebulized 5x/day and 3.3 MIU rhIL-2 SC once daily. The rhIL-2 SYS group received treatment which consisted of intravenous infusion of 18.0 MIU/m2/day rhIL-2 or SC injection of 3.6-18.0 MIU rhIL-2. Some patients in both groups also received IFNalpha. Mean treatment durations were 43 weeks rhIL-2 INH and 15 weeks rhIL-2 SYS. Significantly longer overall survival and progression-free survival durations were observed in the rhIL-2 INH group. The probability of survival at 5 years was 21% for the rhIL-2 INH group. No patients survived 5 years in the rhIL-2 SYS group. A multivariate analysis of overall survival adjusting for differences in baseline characteristics between the two treatment groups resulted in a risk ratio of 0.43 (95% CI 0.30-0.63; P < 0.0001). The data suggested an association between the response (SD or better) and survival, especially in the rhIL-2 INH group. The inhalation regimen was well tolerated. This outcome study suggests that administration of rhIL-2 by inhalation is efficacious and safe in high-risk mRCC patients with pulmonary metastases, who have no other treatment option available.

Administration, Inhalation↗
PubMed2001

Increased neuronal and glial expression of protein kinase C isoforms in neocortex of transgenic Tg2576 mice with amyloid pathology.

We investigated the influence of five- to sevenfold neuronal overexpression of the Swedish mutation of human APP695 (APPsw) in the transgenic mouse strain Tg2576 on neocortical protein kinase C (PKC) expression and subcellular distribution. Using specific antibodies to PKC alpha, PKC beta, PKC gamma, PKC epsilon and PKC zeta isoforms for Western blot analysis, we observed increased immunoreactivity for PKC alpha and PKC gamma isoforms in crude tissue homogenates from the neocortex of 16-month-old APPsw mice as compared with nontransgenic littermates, which was not present in 6 month-old Tg2576 mice. We also observed elevated levels of PKC alpha, PKC beta, PKC gamma and PKC zeta in membrane fractions and reduced concentrations of PKC alpha and PKC gamma in cytosolic fractions of aged Tg2576 mice, indicating that these PKC isoforms are in their activated state. In young, 6-month-old Tg2576 mice, however, the increase in membrane-bound PKC isoforms and concomitant decrease in cytosolic PKC isoforms was much less pronounced, demonstrating the age-dependent nature of alterations in PKC isoforms. Immunocytochemistry of brain sections supported these findings and revealed increased neuronal labelling for PKC alpha, PKC gamma and PKC lambda isoforms in neocortex of 16-month-old APPsw mice compared with nontransgenic littermates, with the increase being strongest for PKC gamma and PKC lambda isoforms. Additionally, PKC gamma and to a lesser extent PKC lambda isoforms were induced in reactive astrocytes in proximity to amyloid plaques. Our data indicate that neuronal overexpression of APPsw causes a dynamic change in neuronal expression and activation of multiple PKC isoforms known to be regulators of proteolytic amyloid precursor protein (APP) processing (PKC alpha) and of neuronal survival (PKC lambda and PKC zeta). The induction of the PKC gamma and PKC lambda isoforms in reactive astrocytes surrounding amyloid plaques might be required for astrocyte activation and astrocytic cytokine expression in response to amyloid plaque formation.

Alzheimer Disease↗
PubMed1999

Insulin-sensitive GLUT4 glucose transporters are colocalized with GLUT3-expressing cells and demonstrate a chemically distinct neuron-specific localization in rat brain.

The insulin-sensitive glucose transporter (GLUT) 4, expressed primarily in peripheral tissue, has recently been detected also in the brain, demonstrating a region-specific distribution. To identify the chemical nature of neurons expressing GLUT4 and to disclose whether GLUT4-containing neurons also express the GLUT3 isoform, combined in situ hybridization for GLUT3 mRNA and double-labeling immunocytochemistry for GLUT4 and different cellular markers was performed in brain sections through rat basal forebrain, cerebral cortex, hippocampus, and cerebellum. In all brain regions examined, GLUT4 immunoreactivity was exclusively found in neurons, and GLUT4-immunoreactive cells were colocalized with neurons expressing GLUT3 mRNA. In rat basal forebrain, cholinergic and parvalbumin-containing gamma-aminobutyric acid-ergic cells demonstrated GLUT4 immunoreactivity, whereas calretinin-, calbindin-D-, and neuronal nitric oxide synthase-containing neurons did not express GLUT4 protein. Because brain GLUT4 transporters have been suggested to play a role in rapidly providing additional glucose to neurons under conditions of high-energy demand, the selective presence of GLUT4 in basal forebrain cholinergic cells may explain the specific vulnerability of these cells to a lack of glucose supply.

Animals↗
PubMed1997

Cardiomyoplasty - improvement of muscle fibre type transformation by an anabolic steroid (metenolone).

Dynamic cardiomyoplasty, a method to support ventricular function by the chronically stimulated latissimus dorsi muscle wrapped around the heart is accompanied by a loss of mass and force of the transplanted muscle. These effects and the fast-to-slow transformation of the muscle could be possibly influenced by the additional administration of anabolic steroids. In this study, the left latissimus dorsi muscles of 12 sheep were electrically conditioned (group A). In 12 other animals (group B), stimulation was combined with the administration of metenolone (100 mg/week). Biopsies were taken from the right and left muscles at the beginning and after 6 and 12 weeks of treatment, frozen and cross-sectioned. The muscle fibre type composition was studied enzymhistochemically (SDH-staining and Myosin-ATPase-reaction) and immunocytochemically (using antibodies against different myosin heavy chains, MHC). Furthermore, the expression of different MHC isoforms was investigated electrophoretically. The untreated latissimus dorsi muscle contains 20% type I fibres expressing slow MHC and 80% type II fibres expressing fast MHC. After 6 weeks, the respective fibre type composition was 42 and 58% (group A) and 80 and 20% (group B). After 12 weeks, the percentage of the type I fibres rose in group A to 59% and in group B to 98%. In accordance with these morphological results, the MHC pattern determined electrophoretically showed a corresponding shift from the fast to the slow isoform. Therefore, the administration of metenolone avoids severe muscle atrophy, and improves and accelerates fast to slow fibre type conversion necessary for successful cardiomyoplasty.

Animals↗
PubMed1994

Effect of an anabolic steroid (Metenolon) on contractile performance of the chronically stimulated latissimus dorsi in sheep.

In 12 sheep the left latissimus dorsi muscles (LD) were conditioned by chronic electrostimulation with a pulse generator (Itrel, Medtronic). Six animals (group B) received a weekly intramuscular injection of an anabolic steroid (Metenolon). After 14 weeks the contraction parameters of the left LDs (group A and B) and right LDs (control group) were investigated. The increase in weight of the conditioned LDs was 11.07% (+/- 1.06%) in group A and 79.97% (+/- 40.8; P < 0.05) in group B. The force capacity under stimulation patterns which were just tetanic was 1.15 kp in group A and 4.13 kp in group B (P < 0.05); under supramaximal stimulation patterns it was 4.23 kp (A) and 6.0 kp (B) (P = ns). The force time relation (dF/dt) was 6.7 kp/s for the left LDs in group A versus 16.4 kp/s for the right LDs (P < 0.01); in group B it was 5.13 kp/s for the left LDs versus 15.8 kp/s for the control muscles (P < 0.05). The maximal force (Fmax) per 100 g muscle weight did not differ significantly (A: 2.42 kp/100 g; B: 2.52 kp/100 g). In conclusion, the LD muscles which were subjected to both anabolic therapy and electrical stimulation showed a significant increase in their force capacity due to an enormous increase in mass. Fibre type transformation was complete only in group B. No fibre deterioration was observable in either group. No anabolic side effects were detected in the animals. With the use of anabolic steroids, therefore, a clearer direct increase in contractility on the left ventricle should be expected ("squeezing" theory), as well as a contribution to reduction in wall tension and myocardial oxygen consumption, respectively, according to Laplace's Law (via the considerable increase in thickness).

Anabolic Agents↗
PubMed1993

[The effect of a Bordetella live vaccine on the occurrence and manifestation of atrophic rhinitis suum and the aerogenous infection burden in field strains of the agent].

A field study was carried out in a large scale unit for swine breeding and fattening with the object to influence the high morbidity rate of Atrophic Rhinitis and pneumonia with the help of a Bordetella live vaccine. The results show that it is possible to decrease the infectious pressure by B. bronchiseptica and to reduce the pathomorphological signs of Atrophic Rhinitis in consequence of the application of the live vaccine. The pathologic-anatomical investigations of nasal turbinates in immunized slaughtered fattening pigs show a significant lower morbidity concerning Atrophic Rhinitis and a higher percentage of pigs without changes at conchae nasales and septum nasi. We find also a lower contamination of the air with B. bronchiseptica field strains during vaccine application. The results also explain that a high infectious pressure by B. bronchiseptica and the possibility of communication between unvaccinated and vaccinated groups of pigs counteract a better efficiency of the vaccine. The decrease of the morbidity rate of Atrophic Rhinitis appears so much more important because toxicogenic Pasteurella multocida strains were isolated from nasal swabs of vaccinated pigs during the investigations. But these strains influenced the Atrophic Rhinitis frequency only accidentally. All results as a whole point out that in pig houses with a high animal density one has to pay more attention to virulent B. bronchiseptica strains than it was been done till now.

Animals↗
PubMed1992

[The tenacity of Bordetella bronchiseptica in the air].

The survival time of Bordetella bronchiseptica (phase I and III) has been determined at a temperature of 21 degrees C and 27 degrees C and at a relative humidity of 32%, 58% and 76% in a rotating aerosol chamber. The highest survival time (118.8 min half-life time) has been found at 21 degrees C and 76% relative humidity in B. bronchiseptica (phase I). An increasing temperature (from 21 degrees C to 27 degrees C) causes a lower survival time. The phase I strains react more sensitive to this changing of environment than phase III strains. An increase of relative humidity leads to a higher survival time concerning phase I strains. In contrast phase III strains of B. bronchiseptica react with an increasing survival time. On the basis of the detected half-life time one must suppose an aerogenous distribution of the germ in all stages of animals, especially in intensive husbandry.

Air Microbiology↗
PubMed1991

[Characterization of strains of Bordetella bronchiseptica isolated from animal housing air and of the airborne infection pressure proceeding from them].

Strains of B. bronchiseptica were isolated from the air in farrowing and weaned piglet houses within the framework of follow-up investigations in an intensive pig breeding and fattening farm with 2600 productive sows. The strains were tested for their biological properties. The results show that virulent B. bronchiseptica-strains have been present as an aerosol in the air of both husbandry systems which refers to the infectious pressure of the animal house air. The number of isolated strains of B. bronchiseptica increases during both rearing phases of piglets. The toxin-forming ability of the strains from weaned piglet houses is higher in comparison with such from farrowing houses. This is a proof for the increasing infectious pressure during the rearing period. One has to take the transmission of virulent strains from animal houses with older pigs to such with younger one into account in case of a common air space. This could result in a lower impact of disinfection during the servicing period. The morbidity rate of atrophic rhinitis could be reduced by 60% in consequence of the application of a B. bronchiseptica-live vaccine. P. multocida couldn't be found neither on nasal mucous membrane nor in animal house air over the whole investigation period. All results as a whole point out that within the framework of the elaboration of a strategy for atrophic rhinitis control in pig houses with a high animal density one has to pay more attention to virulent B. bronchiseptica-strains in addition to toxinogenous strains of P. multocida.

Air Microbiology↗
PubMed1991

[The pathology and pathogenesis of experimental Mycoplasma hyorhinis infection of piglets with and without thermomotoric stress. 1. Pathologico-anatomic, histologic and immunomorphologic study results].

The effect of an experimental Mycoplasma (M.) hyorhinis infection (3 times intranasal instillation of 3-5 ml bouillon with 10(7) Colony forming units [CFU]/ml) in combination with a standard thermomotoric stress (swim-test) was studied in piglets using pathomorphological, immunomorphological and microbiological methods. The 92 piglets were divided into the following 5 groups: swimmers with infection (S-I; n = 19); swimmers without infection (S; n = 19); control piglets with infection (K-I; n = 21); controls without infection, but direct (K1; n = 16) or indirect contact (K2; n = 17) with experimentally infected animals. The experimental or spontaneous infection (direct or aerogenous infection) with M. hyorhinis caused in 30.4% of the piglets an acute or subacute, catarrhal-purulent bronchopneumonia with an interstitial component. Incidence and intensity of pneumonia were significantly higher in the groups with thermomotoric stress (independent from the mode of infection) than in the non-stressed groups. The M. hyorhinis pneumonia was characterized by a limited expansion and a trend to restitution. The causal agent (M. hyorhinis) was demonstrated with immunomorphological methods (immunofluorescence and PAP) in the ciliary zone of the nasal, tracheal and especially on the bronchial mucosa, and occasionally in the bronchioles and alveoli.

Animals↗
PubMed1991

[The pathology and pathogenesis of experimental Mycoplasma hyorhinis infection of piglets with and without thermomotor stress. 2. Electron microscopic study results].

Electron microscopic investigations on the respiratory tract of piglets with and without Mycoplasma hyorhinis infection (10th day of life) partly combined with swim stress (15 degrees C water temperature) (n = 20/20) yielded the following results: colonization of Mycoplasma hyorhinis in the ciliary zone of trachea and bronchi in 15 out of 40 piglets (37.5%); the evidence rate of Mycoplasma hyorhinis in pneumonic lungs (8 out of 12 = 66.7%) was significantly higher than in nonpneumonic lungs (7 out of 28 = 25.0%) and highest in experimentally infected piglets with swim stress (9 out of 16 = 56.2%). Ultrastructural lesions: loss of cilia; bleb-formation; hydropic degeneration and desquamation of ciliary cells; the occurrence of cilia-free and immature epithelial cells; alveolar collapse; microatelectasis; oedematous swelling of pneumocyte I; accumulation of surfactant in the alveoli; hyperplasia of pneumocyte II; exudation of mononuclear macrophages and neutrophils with numerous digestion vacuoles; several lymphocytes and plasma cells, only a little lymphohistiocytic interstitial and peribronchial infiltration. Phagocytized mycoplasmas were found within the resorption vacuoles of neutrophils in the tracheobronchial area, for this once in alveoli, not (more) against in alveolar macrophages. The results were discussed with regard to etiology and pathogenicity of enzootic pneumonia in pigs.

Animals↗
PubMed1990

[The improvement of the tolerance of the kidney for ischemia with the prostacyclin analog iloprost].

Operative trauma, ischemia, release of catecholamines and thermal stimuli in consequence of harvesting, preservation and transplantation deteriorate the renal capillary circulation. By crossing of tolerance limits arises an irreversible transplant damage. The conditions of our examinations were placed in this field. By pre- and postischemic application of Iloprost was demonstrable an improvement of the ischemic tolerance of the kidney. Correction of renal hemodynamics, antiplatelet action and cytoprotection are the reasons of the protective influence of Iloprost in our opinion.

Acute Kidney Injury↗
PubMed1990

[Effect of the stable prostacyclin analog Iloprost on enzyme release during extracorporeal kidney perfusion].

The influence of the stable prostacyclin-analogue Iloprost (Fa. Schering, Berlin) in the enzyme release from extracorporalic perfused kidneys was tested in an experimental investigation. The mechanic hypothermic perfusion was carried out on four different conditions. The estimation of specially cytosolic, lysosomal, and membrane-associated enzymes in the perfusat of the kidneys showed less activities in the Iloprost-protected kidneys. The results after the replantation of the kidneys support the interpretation of the enzyme determinations.

Acid Phosphatase↗
PubMed1989

[Microbiologic studies of the lung clearance of rats after aerogenous long term exposure to ammonia].

The effects of aerogenic long-time exposure of 1,990 female Wistar rats to 30, 50, 100 and 150 nl/l of NH3 for 3, 14, 28 and 42 days on clearance of inhaled bacteria (Staphylococcus aureus, SG 511 strain) were studied together with effects on the clinical condition and behaviour of these test animals. For concentrations below 100 nl/l, action upon pulmonary clearance was found to depend above all on the length of exposure, whereas effects of 150 nl/l proved to depend more strongly on concentration. All concentrations tested tended to act on pulmonary clearance in the form of increased numbers of bacteria which remained in the lungs of the experimental animals. Clinical symptoms attributable to NH3 action were not recordable.

Ammonia↗
PubMed1989

[The disposition and clearance of inhaled bacteria (Staphylococcus aureus) in the lungs of piglets].

Retention in the lungs of 24 piglets of bacteria inhaled following exposure to an aerosol (dv(50)4 micron) of Staphylococcus aureus (SG511 strain), with clearance periods of differentiated lengths, is reported in this paper. Aerosol inhalation led to heterogeneous deposition patterns in the lung. The highest germ count per gram of lung tissue could be re-isolated from the base lobe, while the lowest germ count was retained in the apical lobe. Germ retention in the other lung lobes was somewhere in between these findings. Such differentiation was detectable as early as 20 minutes from the onset of aerosol application and continued to be largely stable even after clearance periods of 2 and 6 hours.

Aerosols↗
PubMed1989

[Histologic and histometric studies of the epiphysis cerebri of the fattening guinea fowl (Meleagris gallopavo) after the use of different light regimens].

Chicken turkey-hens aged 8 weeks were exposed to a light regime of 1 hour light to 2 hours darkness for 8 weeks. Another experimental group was exposed to permanent lighting from hatching to the 16th week of age. The epiphyses of 5 males and females of either group were histologically, histochemically, and histometrically investigated. Significant differences were found to exist between the 2 experimental groups with regard to the nuclear volumes of epiphyseal cells. Epiphyseal cell activity was found to be reduced by permanent lighting.

Animals↗