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Biomedical subjects

H Hertel

Publications and source records attributed to H Hertel.

At least 19 recordsLinked to original sources
PubMed2006

[Perinatal morbidity in pregnancies of women with preconceptional and gestational diabetes mellitus in comparison with pregnancies of non-diabetic women. Results of the perinatal registry of Lower Saxony, Germany].

OBJECTIVE: Pregnancies of women with glucose tolerance disorders are still associated with high maternal and perinatal morbidity. In the present population-based study, we investigated the fetal and neonatal risks and complications in pregnancies of women with preconceptional and gestational diabetes in comparison with pregnancies of non-diabetic women. METHODS: A total of 913,255 pregnancies with 926,685 newborns documented by the Perinatal Registry of Lower Saxony, Germany, between 1987 and 1999 was retrospectively evaluated. In particular, the obstetric parameters of 3439 women with preconceptional diabetes mellitus (PDM, n = 3485 neonates), 4051 women with gestational diabetes mellitus (GDM, n = 4155 neonates) and 905,765 non-diabetic women (NDM, n = 919.053 neonates) were analysed. RESULTS: The diabetes groups had a higher rate of preterm birth < 31st week of gestation (PDM vs. NDM odds ratio [OR] 2.341; GDM vs. NDM OR 1.483) and between the 32nd and 37th weeks of gestation (OR 3.688 and 2.418, respectively). The incidences of pathological cardiotocograms (OR 1.519 and 1.258, respectively) and acidosis as indication for operative delivery (OR 5,015 and 2,102, respectively) were increased in the diabetes groups. There was a higher prevalence of birth weight > 4500 g (OR 2.775 and 2.742, respectively) and >95. percentile (OR 4.268 and 3.610, respectively) in newborns of diabetic women. The higher rate of umbilical arterial pH < 7.00 (OR 2.481 and 1.195, respectively) as well as Apgar score at 1 minute <7 (OR 2.971 and 1.897, respectively) indicated a poorer neonatal outcome in pregnancies of women with diabetes mellitus. The frequency of necessary intubation of the infants was significantly higher in the diabetes group (OR 3.384 and 1.317, respectively). There also was an increased prevalence of intrauterine fetal death in pregnancies of diabetic women (OR 4.197 and 2.511, respectively). CONCLUSION: Pregnancies of women with diabetes mellitus are still correlated with higher perinatal risks and complications. The neonatal morbidity in pregnancies with gestational diabetes mellitus was more similar to that of pregnancies with preconceptional diabetes mellitus than to the morbidity in the group of non-diabetic women. Changes of the parameters within the observation period were the same in all three groups and therefore cannot be attributed to a primary more intensive prenatal care of diabetic women.

Adult↗
PubMed2001

Trocar-site metastasis is not always due to laparoscopy.

The use of laparoscopic surgical techniques for the management of gynecologic malignancies has increased over the last years. Metastasis developing at the trocar insertion site is an emerging problem. We present the case of a 66-year-old woman with endometrial cancer who was diagnosed with an umbilical tumor after laparoscopically assisted vaginal hysterectomy (LAVH) and bilateral salpingoophorectomy. The interval between LAVH and diagnosis of the umbilical tumor was 13 months. The tumor was excised, and metastasis of endometrial cancer was histologically confirmed. Review of computer tomograms taken before LAVH showed a tumor in the umbilical area that had not been recognized before therapy. Therefore, tumor manifestation at the abdominal wall after laparoscopic surgery should not automatically be considered the result of iatrogenic spreading.

Abdominal Neoplasms↗
PubMed2001

Laparoscopic lymph node staging of cervical cancer in the 19th week of pregnancy. A case report.

We present the case of a 39-year-old gravida I para 0 woman who underwent laparoscopic staging of lymph node involvement in cervical cancer in the 19th week of pregnancy. She had been diagnosed with adenosquamous carcinoma of the cervix, stage 1B1, grade 2, with tumor involvement of the lymphovascular space and tumor involved resection margins via a cone biopsy in the 16th week of pregnancy. In order to decide whether it would be safe to proceed with the pregnancy, she was submitted to the laparoscopic exposure and removal of 18 parametric and pelvic lymph nodes. One positive lymph node was detected at the right internal iliac artery; therefore, an open radical hysterectomy with paraaortic lymphadenectomy was performed. This case shows that lymph node staging for cervical cancer can be done laparoscopically in the 2nd trimester. Information yielded during the course of this procedure can be crucial in deciding whether it is possible to preserve the pregnancy.

Adult↗
PubMed2001

Is the decision for colorectal resection justified by histopathologic findings: a prospective study of 100 patients with advanced ovarian cancer.

OBJECTIVE: We compare the indication for colorectal resection in patients with advanced ovarian cancer with histopathologic findings. We describe the effect on pelvic control and morbidity associated with surgery. METHODS: Between February 1995 and March 2001, 100 patients with FIGO stage IIIc ovarian cancer underwent pelvic en bloc resection with excision of the rectosigmoid colon as part of primary or secondary cytoreductive surgery. Decision for resection was made by the surgeon when tumor involvement of the cul-de-sac was suspected. Rectosigmoid infiltration was histopathologically defined as infiltration of the serosa or deeper. RESULTS: In 73 of 100 patients (73%) tumor involvement of the rectum was confirmed histopathologically: infiltration of the serosa in 28 (28%) patients, infiltration of the muscularis in 31 (31%) patients, and infiltration of the mucosa in 14 (14%) patients; in 27 (27%) patients no infiltration was found. Histopathologically confirmed pelvic R0 resection was achieved in 85 (85%) patients. In 11 (11%) patients the pelvic resection margins were tumor-involved and in four (4%) patients visible parametric tumor remained in situ. Pelvic recurrence occurred in 4 (4.7%) of 85 optimally debulked patients compared with 9 (60%) of 15 patients with suboptimal pelvic resection status (P < 0.05). End colostomy could be prevented in 94 (94%) of 100 patients. CONCLUSION: Pelvic en bloc surgery with rectosigmoid resection was justified by histopathologic outcome since deperitonealization with preservation of the rectosigmoid would have left tumor in situ in 73% of patients with suspected cul-de-sac involvement.

Adult↗
PubMed2001

Repellent and toxic effects of plant extracts on subterranean termites (Isoptera: Rhinotermitidae).

The effects of four plant extract formulations on the orientation and survival of subterranean termites were tested. In choice experiments, extract-treated filter paper had a significantly repellent effect on groups of Reticulitermes santonensis De Feytaud, R. virginicus (Banks), Coptotermes formosanus Shiraki, and Schedorhinotermes intermedius Breinli. There was no species-specific difference in avoidance behavior toward the tested concentrations. No-choice experiments revealed toxic properties of all investigated extracts by contact or airborne compounds against R. santonensis. However, high termite mortality was only achieved by forced direct or forced indirect exposure to the plant material, Feeding deterrence or digestive toxicity could not be judged in these experiments. One of the extracts was efficiently used for soil treatments to protect a food substrate against R. santonenis infestation. Extract-treated barriers in the experiments did not affect mortality compared with control trials but prevented termites from penetrating treated soil.

Animals↗
PubMed1998

Human cardiac microvascular and macrovascular endothelial cells respond differently to oxidatively modified LDL.

Oxidation of low density lipoproteins (LDL) is considered a key event in the pathogenesis of atherosclerotic lesions. Disturbed generation of coagulatory and anticoagulatory factors by endothelial cells contributes to thrombosis and the progression of atherosclerosis in coronary arteries. In this study, the effects of native LDL (n-LDL) and oxidized LDL (ox-LDL) on human coronary endothelial cells were measured. The reaction of coronary endothelial cells to LDL were compared with those of cardiac microvascular endothelial cells grown under comparable conditions. LDL was isolated by ultracentrifugation and copper oxidized. The degree of oxidation was expressed as malondialdehyd (MDA) equivalents and was 0.78+/-0.14 nM MDA/mg LDL for native LDL and 13.63+/-1.18 nmol MDA/mg LDL for ox-LDL. Basal secretion of t-PA and PAI-1 activity were higher in macrovascular endothelial cells. Incubation of n-LDL in concentrations ranging from 3 to 100 microM/ml LDL-protein did not change t-PA-secretion, PAI-1 activity or procoagulant activity in both cell types. Ox-LDL (3 to 100 microM/ml LDL protein) decreased t-PA secretion in a concentration dependent manner from 30.9+/-1.7 to 13.7+/-30 ng/ml per 24 h per 10(6) cells (P < 0.01), increased PAI-1 antigen from 2772+/-587 to 4441+/-766 ng/ml per 24 h per 10(6) cells (P < 0.05) as well as PAI-1 activity from 34+/-6 to 55+/-9 AU/ml per 24 h per 10(6) cells (P < 0.05) in macrovascular endothelial cells but had only minor effects on microvascular endothelial cells. Procoagulant activity measured as coagulation time, similarly increased only in macrovascular endothelial cells from 197+/-6 to 76+/-6 s/24 h per 10(6) cells (P < 0.05). The effect on PAI-1 secretion showed a dependency to the degree of oxidation and could be completely blocked by the antioxidant probucol. The angiotensin converting enzyme (ACE), which represents an endothelial enzyme not related to coagulation, remained unchanged during incubation with ox-LDL. Basal ACE activity was higher in microvascular endothelial cells. The higher susceptibility of macrovascular endothelial cells to ox-LDL may partially determine the localization of thrombus formation and the development of atherosclerotic plaques in hyperlipidemic patients.

Antioxidants↗
PubMed1996

Hemicellulose-degrading bacteria and yeasts from the termite gut.

Termites play a major role in the recycling of photosynthetically fixed carbon. With the aid of their symbiotic intestinal flora, they are able to degrade extensively wood constituents such as cellulose and hemicellulose. Nevertheless, the microbial species involved in the degradation of hemicelluloses are poorly defined. The purpose of this paper was to examine the microflora involved in hemicellulose degradation. Different aerobic and facultatively anaerobic bacteria and yeasts were isolated using xylan, arabinogalactan and carboxymethylcellulose as substrates. Gram-positive isolates belonged to the genera Bacillus, Paenibacillus, Streptomyces or the actinobacteria group, while the Gram-negative strains were assigned to the genera Pseudomonas, Acinetobacter, Ochrobactrum, and to genera belonging to the family Enterobacteriaceae. The spectrum and activity of xylan- and arabinogalactan-hydrolysing glycosidases of these new isolates, together with additional bacterial strains originally obtained from enrichments with aromatic compounds were determined.

Animals↗
PubMed1994

Isolation and characterization of macrovascular and microvascular endothelial cells from human hearts.

In vivo models to investigate mechanisms of local hemostasis in the macro- and microvascular coronary circulation are not available. Therefore, we established a culture system of human macro- and microvascular endothelial cells with high cellular yield and high endothelial cell purity. Microvascular endothelial cells from human hearts were isolated by enzymatic treatment of cardiac muscle preparations obtained during heart transplantation. The isolated microvessels were used to start cultures that were subsequently separated and purified from contaminating nonendothelial cells by paramagnetic beads linked to the lectin Ulex europaeus agglutinin I. Macrovascular endothelial cells were isolated from epicardial coronary arteries and purified by paramagnetic beads as well. With this method high purity (< 2% nonendothelial cells) was achieved as judged from fluorescence-activated cell sorting. Immunochemistry demonstrated the expression of several typical endothelial markers. The two endothelial cell types displayed functional heterogeneity in respect to bradykinin degradation and plasminogen activator inhibitor-1 activity. Thus the ability to selectively isolate and culture human macro- and microvascular cardiac endothelial cells provides a valuable tool to systematically investigate endothelial function in human hearts.

Bradykinin↗
PubMed1993

Cultivation and characterization of micro- and macrovascular endothelial cells from the human heart.

In order to investigate processes, such as atherosclerosis and inflammation in vitro, it is necessary to obtain viable and pure endothelial cell cultures from human hearts. To this end, endothelial cells were isolated and cultured from the micro- and macrovasculature of human hearts obtained during heart transplantation. Isolation of capillaries after enzymatic digestion of heart muscle provided a source of microvascular endothelial cells. Contaminating non-endothelial cells were removed by a new technique: paramagnetic beads linked to the lectin ulex europaeus I (UEA-I) were used to select endothelial cells. The resulting cultures contained less than 2% of non-endothelial cells, as judged from immunological staining and fluorescence-activated cell sorting. Both types of endothelial cell displayed typical endothelial properties. They were all positive for factor VIII-related antigen and expressed the endothelial-specific adhesion molecules, CD31 and E-selectin (ELAM-1), after stimulation with cytokines. In addition, they could be labelled with Dil-Ac-LDL, contained angiotensin converting enzyme activity and secreted tissue plasminogen activator, thus demonstrating that typical endothelial functions were preserved in culture.

Capillaries↗
PubMed1992

The spectral input systems of hymenopteran insects and their receptor-based colour vision.

Spectral sensitivity functions S(lambda) of single photoreceptor cells in 43 different hymenopteran species were measured intracellularly with the fast spectral scan method. The distribution of maximal sensitivity values (lambda max) shows 3 major peaks at 340 nm, 430 nm and 535 nm and a small peak at 600 nm. Predictions about the colour vision systems of the different hymenopteran species are derived from the spectral sensitivities by application of a receptor model of colour vision and a model of two colour opponent channels. Most of the species have a trichromatic colour vision system. Although the S(lambda) functions are quite similar, the predicted colour discriminability curves differ in their relative height of best discriminability in the UV-blue or blue-green area of the spectrum, indicating that relatively small differences in the S(lambda) functions may have considerable effects on colour discriminability. Four of the hymenopteran insects tested contain an additional R-receptor with maximal sensitivity around 600 nm. The R-receptor of the solitary bee Callonychium petuniae is based on a pigment (P596) with a long lambda max, whereas in the sawfly Tenthredo campestris the G-receptor appears to act as filter to a pigment (P570), shifting its lambda max value to a longer wavelength and narrowing its bandwidth. Evolutionary and life history constraints (e.g. phylogenetic relatedness, social or solitary life, general or specialized feeding behaviour) appear to have no effect on the S(lambda) functions. The only effect is found in UV receptors, for which lambda max values at longer wavelengths are found in bees flying predominantly within the forest.

Animals↗
PubMed1992

Opponent colour coding is a universal strategy to evaluate the photoreceptor inputs in Hymenoptera.

Behavioural tests were carried out with 9 hymenopteran insect species, which ranked certain sets of coloured stimuli according to their subjective similarity to a previously memorized stimulus. Kendall's tau co-efficient is employed for the analysis of correlation between these similarity rankings and the colour distance rankings predicted by various models of neural colour computation. The models are based on the measured spectral sensitivities of photoreceptor colour types and use a variety of simple colour coding systems to derive hypothetical colour distances. The correlation between the predictions of the models and the behavioural results serves as a measure for the likelihood of existence of a colour coding system. In all species, the similarity rankings can be best explained by assuming that colour is coded on a perceptual level by two colour opponent mechanisms. Brightness differences are ignored, indicating that an intensity-coding sub-system is not used in colour discrimination by the insects investigated. The weighting factors of the colour opponent mechanisms differ between species in detail, but not in the principles involved. It is thus possible to employ a standard measure of perceptual colour distance (colour hexagon distance) to predict the capacities of colour discrimination adequately in all the tested insects.

Agonistic Behavior↗
PubMed1989

[Low dosage retinol and L-cystine combination improve alopecia of the diffuse type following long-term oral administration].

In a pilot study (I) the efficacy of a new combination therapy for hair loss of the diffuse type was tested in 36 patients, followed by a double blind study with 47 patients. The daily dosage was 18,000 IE retinol, 70 mg L-cystine and 7000 mg gelatin. The clinical efficacy was evaluated by standard methods, such as the preparation of trichograms and measurement of the hair density before and after treatment. The pilot study demonstrated a significant improvement, with reduction of the telogen rate by 8.3%, an increase of the anagen rate by 11%, and an increase of the hair density by 6.9%. In the double blind study (II) the trichogram showed a significant decrease of the telogen rate by 13.5% compared with pathological baseline values. There was no change in the placebo group. The lowered anagen rate of 47.2% was improved by 8%, whereas the mean value in the placebo group decreased from 47.7% to 39.9%. In addition, the percentage of dysplastic anagen hairs improved by 7.4%, as against further impairment with an increase of 26% in the placebo group. During oral therapy no systemic side-effects were detected. We conclude that long-term oral therapy with high doses of L-cystine and gelatin in combination with vitamin A may have beneficial effects on diffuse hair loss.

Administration, Oral↗
PubMed1988

[Disorder of hair growth in hyperprolactinemia].

Functional hyperprolactinemia was found in five female patients, 25-35 years old, seeking medical consultation for hair loss, together with hypertrichosis (4x), disturbances of cyclic bleeding periods (4x), secondary amenorrhea (2x), galactorrhea (2x), seborrhea (2x) and persisting acne (1x). Other hormonal parameters including testosterone levels and thyroid gland function tests were unchanged. Prolactinoma was excluded by x-ray diagrams, partly also by computer tomograms of the sella. In two patients increased telogen effluvium was found by trichogram examination with some dystrophic hairs; in one patient only dystrophic hairs were seen, whereas, in two cases, hair loss was not present at the time of our clinical examination. These observations indicate that cutaneous symptoms such as seborrhea, acne, hypertrichosis/hirsutism, alopecia(= SAHA syndrome) may evidently occur in hyperprolactinemia, representing or mimicking androgen-induced skin symptoms. In such cases, therefore, evaluation of prolactin levels together with androgen blood levels and thyroid gland function tests should be performed to exclude underlying endocrinopathy.

Acne Vulgaris↗
PubMed1987

Marking and recording of monopolar cells in the bee lamina.

Monopolar cells in the lamina ganglionaris of the honeybee, Apis mellifera, were marked individually for the first time and intracellular recordings made. The electrophysiological responses were mainly hyperpolarizing with peaks and descending plateaux; one specific cell gave depolarizing responses, sustained in UV, and phasic at other wavelengths. Spectral sensitivity curves obtained by the spectral scanning method showed maximum sensitivity at 520 nm. Three morphological cell types were encountered, all of which differ considerably from those described by Ribi (1).

Animals↗
PubMed1985

[Rectoscopy: rigid or flexible? A comparative study].

The customary rigid rectoscope was compared prospectively, with a new, flexible one (prototypes of Olympus Opt. and Fuji) in each of 114 patients selected at random. Maximal depth of introduction was reached on average after 1 min with the rigid instruments, after 1 min 40 sec with the flexible one. Mean depth of introduction was 16 cm for the rigid and 33 cm for the flexible one. In 21 patients (18.4%) additional information was obtained with the flexible rectoscope. 80% of patients reported that the flexible instrument caused them no or only slight discomfort. Skill in using the flexible instrument can be quickly acquired.

Fiber Optic Technology↗