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Biomedical subjects

B Hartmann

Publications and source records attributed to B Hartmann.

At least 91 records · Page 5Linked to original sources
PubMed1997

The impact of risk factors and pre-existing conditions on the mortality of burn patients and the precision of predictive admission-scoring systems.

Clinical experience has shown that concomitant diseases and risk factors have a significant influence on the patient's outcome. Since none of the currently available score systems consider the impact of concomitant diseases or risk factors on burn trauma mortality, the present study was planned to further evaluate the role of these factors. Four hundred and ninety-eight patients could be included in this retrospective analysis of prospectively collected data. Parameters documented were: sex, age, weight, height, laboratory data, TBSA, inhalation trauma (IHT), full thickness (3 degrees) burn and pre-existing conditions. Single-variable analysis (SVA), logistic regression and CART analysis were performed. The data confirm the role of age and TBSA as the strongest prognostic variables. Chronic alcohol abuse and smoking, IHT and pre-existing cardiac and neurologic conditions were also found to be significant. Borderline groups could be identified in the ABSI score (7-10), where the risk factors cause 'mortality-shifting'. It can be concluded that risk factors and pre-existing conditions have a significant impact on the prognosis of burn mortality and should be incorporated into further refinements of burn admission scores.

Adolescent↗
PubMed1997

The value of early enteral nutrition in the prophylaxis of stress ulceration in the severely burned patient.

A retrospective analysis of prospectively collected data was performed to compare the frequency of upper gastrointestinal bleeding (GIB) in seriously burned patients treated with either cimetidine and antacids or enteral nutrition for ulcer prophylaxis. Five hundred and twenty-six seriously burned patients admitted to the burn intensive care unit of the BG Trauma Centre Ludwigshafen during a 4-year period were included into the study. All patients admitted to the burn unit from 1989 to 1991 received i.v. cimetidine (400 mg q4) for ulcer prophylaxis. If the intragastric pH dropped below 3.5, gastric pH was titrated with antacids up to > or = 4 via nasogastric tube. During the second 2-year period (1992-1993) early enteral nutrition alone was regarded to be ulcer protective and no further interventions for ulcer prophylaxis were routinely performed. Signs of overt upper GIB were monitored and documented through the entire study period. The overall occurrence rate of upper GIB in the cimetidine/antacids (C/A) group (n = 253) was 8.3 per cent with six cases of serious bleeding in five patients (1.98 per cent). In the enteral nutrition (EN) group (n = 273) the overall incidence of GIB was 3.3 per cent with two cases of serious bleeding (0.73 per cent). There were no deaths directly related to ulcer haemorrhage. The difference in the overall frequency of overt GIB between the groups studied was statistically significant (< 0.05). In our experience, early enteral nutrition is effective in the prevention of stress haemorrhage in the upper gastrointestinal tract. Additional medicinal prophylaxis is not required in burn patients.

Administration, Oral↗
PubMed1997

Difference of LH and FSH secretory characteristics and degree of concordance between postmenopausal and aging women.

OBJECTIVE: Several neuroendocrine changes occur at menopause and the present study aimed to verify whether the episodic release and the degree of concordance of LH and FSH differs between early and late postmenopausal women. METHODS: Postmenopausal (n = 32) women were enrolled and subdivided in two groups according to the menopausal age: group A (n = 22), patients with more than 2 but less than 5 years from the occurrence of menopause; group B (n = 10), patients with more than 15 years from the occurrence of menopause. All subjects underwent a pulsatility study (4 h, sampling every 10 min) to assess LH and FSH secretory characteristics and their degree of concordance. RESULTS: Mean +/- S.E.M. LH and FSH plasma levels were lower in older women than in postmenopausal women (P < 0.01). The secretory pattern was pulsatile for both LH and FSH and their pulse amplitudes were lower in aged women (P < 0.01). No significant difference was observed in terms of pulse frequency between the two groups. LH and FSH pulses were co-secreted in early postmenopausal women while such a concordance was lost in older women. CONCLUSIONS: Late postmenopause is characterized by the reduction of the amplitude of gonadotropin pulses in comparison to women in early postmenopause, reflecting changes of both GnRH secretion and/or pituitary responsiveness to GnRH. The age-related loss of concordance between LH and FSH pulses discloses the existence of a hidden FSH stimulating system, which drives FSH episodic release independently and more promptly than GnRH.

Aging↗
PubMed1997

Raynaud's phenomenon in vibration syndrome: the impact of cold feet on skin temperature and vasomotion of the hand after immersion in cold water.

Patients with vibration syndrome, suffering from Raynaud's phenomenon, are sensitive to cold. Rewarming time, after local cooling, is delayed. The present study evaluated whether rewarming of the hand after cooling is influenced by the temperature of the feet. In five Japanese patients (former forest workers) with vibration syndrome, suffering from Raynaud's phenomenon, and in five healthy controls, temperature changes of the hand after cooling were registered under the two test situations (on different days) with the feet immersed in water of 35 degrees C or 20 degrees C, respectively. In both patients and controls (in both groups, in four of five cases) rewarming of the hand after cooling was faster when the feet were immersed in cold water, compared with when the feet were immersed in warm water. In this test situation, the systemic thermoregulative counterreaction appears to be more important for rewarming of the hand after cooling than a possible synchronous passive reaction accompanying warming of the feet. A deliberate training of the systemic counterreaction may prove beneficial for patients with Raynaud's phenomenon.

Adult↗
PubMed1997

Population control I: Birth of an ideology.

Population control, as a major international development strategy, is a relatively recent phenomenon. However, its origins reach back to social currents in the 19th and early 20th centuries, culminating in an organized birth control movement in Europe and the United States. The conflicts and contradictions in that movement's history presage many of today's debates over population policy and women's rights. Eugenics had a deep influence on the U.S. birth control movement in the first half of the 20th century. After World War II private agencies and foundations played an important role in legitimizing population control as a way to secure Western control over Third World resources and stem political instability. In the late 1960s the U.S. government became a major funder of population control programs overseas and built multilateral support through establishment of the U.N. Fund for Population Activities. At the 1974 World Population Conference, Third World governments challenged the primacy of population control. While their critique led population agencies to change their strategies, population control remained a central component of international development and national security policies in the United States.

Eugenics↗
PubMed1997

Population control II: The population establishment today.

Although population assistance represents a relatively small share of official development assistance, it influences many other aspects of development planning. The organizations that comprise the population establishment have a common purpose--the reduction of population growth in the Third World--but they are not homogeneous and sometimes have conflicting goals and strategies. National governments, multilateral agencies, nongovernmental organizations, foundations, academic centers, and pressure groups all contribute to creating and sustaining what has become a virtual population control industry. Through scholarships, travel grants, awards, and favorable publicity, Third World elites have been encouraged to join the population establishment. The World Bank, the U.S. Agency for International Development, and the U.N. Fund for Population Activities have pursued explicit strategies for pressuring Third World governments to design and implement population policies, most recently in Africa.

Coercion↗
PubMed1997

[Significance of the circadian fluctuation of estradiol, somatotropin, IGF I, prolactin, cortisol and DHEA-S for the body-shape of pre- and postmenopausal women].

With 23 postmenopausal and 33 premenopausal females the interactions between circadianic secretion patterns of estradiol, growth hormone, IGF I, prolactin, DHEA-S as well as cortisol and the amount and distribution of subcutaneous body fat, estimated by using 10 absolute body measures and 10 anthropometric indices were tested. Premenopausal and postmenopausal women differed regarding the secretion patterns of estradiol and growth hormone significantly from each other. Furthermore it turned out, that the daily secretion rate, estimated by using the area under the curve, of growth hormone and estradiol correlated significantly with the amount and the distribution of body fat. In both proband groups more corpulent women had lower growth hormone levels and higher estradiol levels. The age dependent reduction of growth hormone secretion may be co-responsible for the general weight gain with increasing age. The reduced estrogen secretion however, seems to be the major determinant of the expression of a more masculine type of fat distribution during climacteric and after the menopause.

Adipose Tissue↗
PubMed1996

Solution structure of the CpG containing d(CTTCGAAG)2 oligonucleotide: NMR data and energy calculations are compatible with a BI/BII equilibrium at CpG.

We report the analysis of the solution structure of the DNA duplex d(CTTCGAAG)2 compared to that of d(CATCGATG)2, the two oligonucleotides being related by the permutation of residues 2 and 7. An earlier study has demonstrated the malleability of CpG in the tetrad TCGA of d(CATCGATG)2 [Lefebvre et al. (1995) Biochemistry 34, 12019-12028]. Conformations of d(CTTCGAAG)2 were evaluated by (a) two-dimensional NMR, including proton and phosphorus experiments, (b) adiabatic mapping of the conformational space, (c) restrained molecular mechanics undertaken with sugar phase angle, epsilon-zeta difference angle, and NOE distances as input, and (d) back-calculation-refinement against NOE spectra at various mixing times. d(CTTCGAAG)2 like d(CATCGATG)2 exhibits a B-DNA conformation. However, significant differences are noted between the two oligonucleotides, extending up to the central CpG step, although this step resides in the same TCGA tetrad in both sequences. In structures obtained with refined NMR data, CpG adopts, for instance, a greater twist and a higher guanine phase within d(CTTCGAAG)2 compared to d(CATCGATG)2. In the former oligonucleotide, the structure of CpG resembles strikingly that found in the ACGT tetrad of the cAMP responsive element [Mauffret et al. (1992) J. Mol. Biol. 227, 852-875]. Moreover, two conformers with CpG either in the BII state (epsilon, zeta = g-, t) or in the BI state (epsilon, zeta = t, g-) are found equally stable for d(CTTCGAAG)2. The energy barrier from BI to BII comes to only 5.7 kcal/mol, and the path of the transition is very short. When calculations on d(CTTCGAAG)2 are performed taking the BI/BII equilibrium into account, the agreement with both the 1H and 31P data is found better than in the case with a single conformation taken alone. The BI/BII equilibrium may also occur in d(CATCGATG)2, but the amount of BII conformer is now found weaker compared to its analogue. The ability of the CpG phosphate groups to adopt the BII conformation could provide a satisfying explanation for the high mutation rates observed at these sites.

CpG Islands↗
PubMed1996

Interleukin-12 gene-expression of macrophages is regulated by nitric oxide.

Interleukin-12 is a heterodimeric cytokine, mainly produced by macrophages. In our present study we demonstrate that interleukin-12 expression is regulated by nitric oxide. Incubation of the macrophage cell line IC 21 with interferon-gamma gave rise to both interleukin-12 p40 mRNA and nitric oxide production. The concurrent addition of the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine inhibited nitrite production and in parallel completely suppressed interleukin-12 p40 mRNA formation. This indicated that endogenous nitric oxide synthase activity was required for IL-12 p40 gene expression. Exposure of the cells towards the nitric oxide generating compounds nitroprusside or S-nitroso-N-acetyl-penicillamine induced interleukin-12 p40 mRNA. Maximal mRNA levels were induced with nitric oxide donors at 1 microM concentration. We conclude that nitric oxide may exert an autoregulatory and paracrine control of interleukin-12 gene expression.

Animals↗
PubMed1996

The Drosophila tumor suppressor gene, dlg, is involved in structural plasticity at a glutamatergic synapse.

BACKGROUND: Synaptic contacts between neurons and their targets are dynamic entities that can change depending on developmental and functional states of the pre- and postsynaptic cell. However, the molecular factors involved in this plasticity have remained largely unknown. We have demonstrated previously that the Drosophila tumor suppressor gene, discs-large (dlg), is expressed at neuromuscular synapses, and is required for normal synapse structure. A family of dlg homologues is also expressed at mammalian synapses, where they interact with the N-methyl-D-aspartate receptor and ion channels. Here, we provide the first demonstration of the involvement of dlg in structural synaptic plasticity during postsynaptic target growth. RESULTS: We used a temperature-sensitive dlg allele to demonstrate that there are two stages, late embryogenesis and larval stages, at which dlg is necessary for normal formation of synapses. These stages are coincident with dynamic DLG expression at presynaptic sites in the late embryo, and at postsynaptic regions in the larva. Ultrastructural and confocal analyses reveal that Drosophila neuromuscular junctions undergo a dramatic expansion of the postsynaptic apparatus, which is paralleled by target muscle growth. We show that this process of postsynaptic expansion is partially blocked in dlg mutants. CONCLUSIONS: Our results demonstrate that dlg is required during synapse maturation. We show that dlg is involved in the determination of postsynaptic size during target muscle growth. Because motoneuron targets in the larva are continuously growing, synaptic contacts are structurally plastic, undergoing continuous expansion. We conclude that dlg plays an important role in this form of structural synaptic plasticity.

Animals↗
PubMed1996

Effects of hormonal replacement therapy on plasma sex hormone-binding globulin, androgen and insulin-like growth factor-1 levels in postmenopausal women.

Plasma sex hormone-binding globulin (SHBG) levels are important in the regulation of plasma free and albumin-bound androgens and estrogens. In postmenopausal women associated to the decrease of estrogen production, a decrease of plasma SHBG levels occurs. Hormone replacement therapy (HRT) in postmenopausal women modulates plasma SHBG levels, in relationship with the different regimens and routes of administration. The present study aimed to compare the effect of different HRT on plasma SHBG levels in relationship with the changes of plasma androgen [dehydroepiandrosterone sulphate (DHEAS), testosterone (T), androstenedione (A)] and insulin-like growth factor-1 (IGF-1) levels. In a retrospective study 443 postmenopausal women were studied and divided into 2 groups. The group 1 (n = 170) was subdivided in 4 groups of women as follows: A) treated with transdermal 17-beta estradiol + medroxyprogesterone acetate, B) treated with oral conjugated estrogens, C) treated with sequential HRT (estradiol valerate (EV) + norgestrel), and D) treated with a combined HRT (micronized estradiol (E2) + noretisterone acetate). Women of group 2 (n = 273) did not receive HRT and served as controls. All groups of women treated with different HRT showed plasma estradiol levels significantly higher than controls (p < 0.01), showing the highest values in women treated with oral HRT. Plasma SHBG levels were not significantly different between patients treated with transdermal 17-beta estradiol + medroxyprogesterone acetate and controls. On the other hand, all the groups of patients treated with oral conjugated estrogen with or without progestagens showed plasma SHBG levels significantly higher than controls (p < 0.01). Plasma SHBG levels were higher in the group treated with estrogen alone than in groups of women treated with sequential or combined HRT. Plasma DHEAS, T and A levels in patients treated with different HRT regimens were in the same range of levels as control women. Plasma IGF-1 levels were not significantly affected by the various HRT regimens and remained in the same range as controls. In conclusion, plasma SHBG levels increase following oral HRT while are not affected by transdermal HRT. Plasma IGF-1 and androgen levels are not influenced from oral or transdermal HRT.

Adult↗
PubMed1996

Decreased sexual interest and its relationship to body build in postmenopausal women.

OBJECTIVES: The relationship between body build, androgen levels and changes in sexual interest after menopause was investigated in 171 postmenopausal women from Vienna, Austria. METHODS: All women were interviewed using a structured questionnaire. Body build was determined by employing five absolute body dimensions and four anthropometric indices. RESULTS: Body weight, as well as the amount of subcutaneous centripetal fat (such as in the chest, waist and hip region), were statistically significantly related to the degree of reduced sexual interest. Corpulent and heavy women suffered far more frequently from a severe decrease in sexual interest after menopause. Statistically significant associations between androgen levels and decrease in sexual interest could not be demonstrated. CONCLUSIONS: Reduced sexual interest is associated with a kind of body type not corresponding to the culture-specific beauty ideals of our society, first of all evident in women whose menopause occurred relatively early.

Adult↗
PubMed1996

Regulation of synapse structure and function by the Drosophila tumor suppressor gene dlg.

Mutations of the tumor suppressor gene discs-large (dlg) lead to postsynaptic structural defects. Here, we report that mutations in dlg also result in larger synaptic currents at fly neuromuscular junctions. By selectively targeting DLG protein to either muscles or motorneurons using Gal-4 enhancer trap lines, we were able to rescue substantially the reduced postsynaptic structure in mutants. Rescue of the physiological defect was accomplished by presynaptic, but not postsynaptic targeting, consistent with our finding that miniature excitatory junctional currents were not changed in dlg mutants. These results suggest that DLG functions in the regulation of neurotransmitter release and postsynaptic structure. We propose that DLG is an integral part of a mechanism by which changes in both neurotransmitter release and synapse structure are accomplished during development and plasticity.

Animals↗
PubMed1996

Metabolic activation of islet cells improves resistance against oxygen radicals or streptozocin, but not nitric oxide.

In the present study we investigated the effect of metabolic activation on the susceptibility of isolated rat pancreatic islet cells to the alkylating beta-cell toxin streptozocin (SZ), reactive oxygen intermediates (ROI), and nitric oxide (NO). The latter two represent physiologically occurring mediators involved in the autoimmune destruction of islet cells. ROI were generated by the enzyme xanthine oxidase, and NO was released from sodium nitroprusside. During 18 h of culture at a physiological glucose concentration (5 mmol/L), 75% of the islet cells were lysed by SZ, 81% by ROI, and 74% by NO, as determined by the trypan blue exclusion assay. Increasing concentrations of glucose or the nonnutrient stimulators theophylline and glibenclamide dose-dependently reduced SZ- and ROI-mediated islet cell lysis. In the presence of 29 mmol/L glucose, 5.5 mmol/L theophylline, or 10 micrograms/mL glibenclamide, SZ-induced lysis was reduced to 15%, 22%, or 15%, and ROI-induced lysis was reduced to 20%, 34%, or 15%, respectively. In contrast, stimulation by glucose, theophylline, or glibenclamide did not improve resistance against NO. The protection against SZ and ROI was associated with preserved mitochondrial activity, as determined by the ability of the islet cells to convert the tetrazolium salt 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide into its formazan. Elevation of the glucose concentration from 5.5 to 29 mmol/L increased the residual mitochondrial activity from 45% to 80% in SZ-exposed islet cells and from 21% to 78% in ROI-exposed cells. Conversely, the lack of protection against NO correlated with no preservation of mitochondrial activity in the presence of high concentrations of glucose, theophylline, or glibenclamide. In conclusion, our results show that metabolic stress does not render islet cells more susceptible to inflammatory insults in vitro. Rather, an increased mitochondrial energy supply improves the resistance against SZ and ROI, whereas the toxicity of NO was independent of islet cell activity.

Animals↗
PubMed1996

Experience with the modified Meek technique.

In 1958 Meek described the so called Meek-Wall dermatome to cut postage stamp skin grafts. This method was eclipsed by the introduction of mesh skin grafts. In 1993 Kreis and colleagues reintroduced a modified Meek technique using a dermatome running on compressed air. This technique has been used in our burn unit since August 1994. The aim of this paper is to compare the modified Meek technique with the mesh graft technique. Within a period of 20 months 41 patients were grafted using the modified Meek technique. The mean TBSAB was 54.4% with 50.0% full thickness burns. All patients were excised early. The expansion ratio was 1:4 and 1:6. In 20 patients the Meek technique was used exclusively for grafting of the trunk and the extremities with the exception of face, neck and hands. In 3 patients with a mean TBSAB of 68.3% a combination of postage stamp autologous skin grafts and cultured epithelial autografts (CEA) was applied. Compared with the mesh graft technique the Meek technique showed the following advantages: 1. The Meek method provides the true expansion ratio. 2. Small graft remnants can be utilized. 3. Grafting of full thickness burns up to 70 to 75% TBSAB becomes possible with one harvest of the donor sites. 4. The reliability of graft take is equal or better. 5. Epithelialization is achieved within 3 to 4 weeks depending on the expansion ratio. 6. The combination of widely expanded postage stamp split thickness grafts and CEA provides an excellent take rate and durable wound closure within a short time and avoids the problems associated with the engraftment of CEA on fascia. The method is simple but more demanding than the mesh technique. Compared with the mesh graft technique the preparation of Meek grafts is more time consuming and requires more staff than the Mesh technique. The cost of materials is higher. In our experience complete coverage of the Meek grafts with an overlay of meshed allografts after removal of the gauze as recommended by Kreis is not necessary using the 1:4 expansion ratio. Greater expansion ratios necessitate an overlay with meshed allografts. Regarding the scar formation no significant differences were observed compared with the mesh graft technique. In conclusion the modified Meek technique is reliable and simple to perform. This technique provides a sufficient expansion ratio enabling to graft patients with burns up to 75% TBSA with only one harvest of donor sides and without the necessity of CEA. In our opinion the Meek technique is reliable and simple to perform. This technique provides a sufficient expansion ratio enabling to graft patients with burns up to 75% TBSA with only one harvest of donor sides and without the necessity of CEA. In our opinion the Meek technique is advantageous in patients with burns greater than 45% TBSAB. In smaller burns mesh grafts should be used because of lower material cost and staff requirements. Especially in extensively burned patients the Meek technique may be cost effective avoiding the need of CEA.

Adolescent↗
PubMed1996

Serum levels of sex hormones, thyroid hormones, growth hormone, IGF I, and cortisol and their relations to body fat distribution in healthy women dependent on their menopausal status.

The relations between 10 anthropometric variables describing the amount of adipose tissue and the serum levels of thyroxine, triiodothyronin, thyroid stimulating hormone, estradiol, progesterone, 17-hydroxyprogesterone, prolactin, luteinizing hormone, follicle stimulating hormone, DHEA-S, androstendion, testosterone, sex hormone binding globulin, growth hormone, IGF I as well as cortisol were investigated in 39 premenopausal and 38 postmenopausal women. Several statistically significant correlations between hormonal parameters and the amount and the distribution of subcutaneous fat tissue were found for the premenopausal group. The postmenopausal probands, however, showed fewer statistically significant connections between the two trait systems. The correlation patterns in both proband groups resembled each other. Only with regard to the gonadotropines (LH and FSH) a difference in the algebraic sign of the correlation coefficients can be observed for pre- and postmenopausal probands. The multiple regression analysis corroborated the hypothesis that hormonal parameters are responsible for somatic changes after menopause.

Adipose Tissue↗
PubMed1995

Structural behavior of the CpG step in two related oligonucleotides reflects its malleability in solution.

We report on the determination of the solution structure of two sequence-related oligonucleotides, d(GTACGTAC)2 and d(CATCGATG)2. Results have been obtained by using a combined approach of (a) two-dimensional NMR, including proton and phosphorus experiments, (b) restrained molecular mechanics performed with sugar phase angle, backbone epsilon angle, and NOE distances as input, and (c) back-calculation refinements against the NOE spectra at various mixing times. The two oligonucleotides adopt the B-DNA structure with, however, noticeable differences centered on their core sequence and especially the CpG step. Due to the permutation of its flanking residues, the CpG step modifies its twist values and backbone epsilon value; globally, the CpG step appears more flexible within the tetranucleotide TCGA than ACGT. The solution structure of d(GTACGTAC)2 differs from the previously reported X-ray structure, which was found to be A-form throughout [Takusagawa, F. (1990) J. Biomol. NMR 3, 547-568]. On the other hand, in the X-ray structure of d(CCAACGTTGG)2 [Privé et al. (1991) J. Mol. Biol. 217, 177-199] the structure of the ACGT sequence is similar to that found in solution d(GTACGTAC)2. Similarly, the central TCGA tetranucleotide of d(CATCGATG)2 presents a solution structure analogous to that observed on the X-ray structures of both d(CGATCGATCG)2 [Grzeskowiak, et al. (1991) J. Biol. Chem. 266, 8861-8883] and d(CGATCGmeATCG)2 [Baïkalov, et al. (1993) J. Mol. Biol. 231, 768-784]. At the end we discuss the possible biological significance of the particular structures exhibited by the ACGT and TCGA tetranucleotides.

Base Sequence↗