Weight reduction by sibutramine in obese subjects in primary care medicine: the SAT Study

BACKGROUND

Sibutramine is a selective serotonin and noradrenaline reuptake inhibitor that is known to reduce body weight. The efficacy of this drug in primary care medicine is currently unknown.

OBJECTIVE

To study, in a primary healthcare setting, the effect of a standardized non-pharmacological treatment program and 15 mg sibutramine or placebo on long-term weight reduction in obese subjects with a body mass index >or= 30 and < 40 kg/m(2).

DESIGN

A multicentre, double-blind, placebo-controlled, randomized, parallel group comparison over 54 weeks of continuous therapy.

SETTING

33 general practitioners in Germany.

SUBJECTS

389 obese patients were recruited of whom 362 were randomized.

MEASUREMENTS

Primary measure was weight reduction at week 54; others included reduction in BMI, waist circumference, waist-hip ratio, blood pressure and blood lipids.

RESULTS

348 obese subjects were analyzed using an intention-to-treat analysis. Mean weight loss in the sibutramine (S) group was 8.1 +/- 8.2 kg vs. 5.1 +/- 6.5 kg in the placebo (P) group (p < 0.001; Intent-to-treat analysis). More subjects lost more than 5 % and 10 % of initial weight with sibutramine than with placebo (5 %, S: 62.6 %, P: 41.4 %, p < 0.001; 10 %, S: 40.8, P: 19.0 %, p < 0.001). Weight loss was accompanied by an improvement in the lipid profile, in particular, an increase in HDL-cholesterol and a decrease in fasting triglycerides. In both groups, systolic and diastolic blood pressure decreased in those with moderate hypertension and remained unchanged in those with normal blood pressure at baseline. There was a modest increase in heart rate in S (1.9 beats/min) vs. P (- 0.9 beats/min) (p < 0.05).

CONCLUSIONS

Under primary care conditions, sibutramine 15 mg daily proved to be a safe and effective drug for additional weight loss in obese subjects undergoing a comprehensive weight reduction program.

Long-term effects of HIV-1 protease inhibitors on insulin secretion and insulin signaling in INS-1 beta cells

The mechanism by which chronic treatment with HIV (human immunodeficiency virus)-1 protease inhibitors leads to a deterioration of glucose metabolism appears to involve insulin resistance, and may also involve impaired insulin secretion. Here we investigated the long-term effects of HIV-1 protease inhibitors on glucose-stimulated insulin secretion from beta cells and explored whether altered insulin secretion might be related to altered insulin signaling. INS-1 cells were incubated for 48 h with different concentrations of amprenavir, indinavir, nelfinavir, ritonavir or saquinavir, stimulated with 20 mM d-glucose, and insulin determined in the supernatant. To evaluate insulin signaling, cells were stimulated with 100 nM insulin for 2 min, and insulin-receptor substrate (IRS)-1, -2 and Akt phosphorylation determined. Incubation for 48 h with ritonavir, nelfinavir and saquinavir resulted in impaired glucose-induced insulin secretion at 2.5, 5 and 5 microM respectively, whereas amprenavir or indinavir had no effects even at 20 and 100 microM respectively. The impaired insulin secretion by ritonavir, nelfinavir and saquinavir was associated with decreased insulin-stimulated IRS-2 phosphorylation, and, for nelfinavir and saquinavir, with decreased insulin-stimulated IRS-1 and Thr308-Akt phosphorylation. No such effects on signaling were observed with amprenavir or indinavir. In conclusion, certain HIV-1 protease inhibitors, such as ritonavir, nelfinavir and saquinavir, not only induce peripheral insulin resistance, but also impair glucose-stimulated insulin secretion from beta cells. With respect to the long-term effect on beta-cell function there appear to be differences between the protease inhibitors that may be clinically relevant. Finally, these effects on insulin secretion after a 48 h incubation with protease inhibitor were associated with a reduction of the insulin-stimulated phosphorylation of insulin signaling parameters, particularly IRS-2, suggesting that protease inhibitor-induced alterations in the insulin signaling pathway may contribute to the impaired beta-cell function.

Das Osteoidosteom im Bereich der Hand und des Handgelenks

PURPOSE

Osteoid osteoma is a painful benign bone tumour and very rare in the hand and wrist. Diagnosis may be very difficult and often is made after multiple previous diagnostic errors.

METHODS AND PATIENTS

From 1992 until 2003, 22 patients (11 men, 11 women) were operated on because of an osteoid osteoma of the hand or wrist in our hospital. The mean age was 30 years, ranging from 14 to 62 years. We retrospectively analysed patient records. A clinical examination with X-ray control was performed in 14 patients. Five patients were questioned by phone; three patients were lost to follow-up.

RESULTS

The mean time interval between onset of symptoms and surgical removal of the tumour was approximately two years. Symptoms were often non-specific; clinical findings varied according to localisation of the tumour. Conventional X-rays did not always show typical pathological findings. Bone scanning and gadolinium-enhanced MRI proved to be very sensitive in detecting the pathological process. High-resolution CT-scan demonstrated the nidus exactly. Usually, operative removal of the nidus resulted in immediate pain relief. At follow-up, 18 patients were free of pain. However seven patients had had a revision operation; in four of those, osteoid osteoma recurred once again.

CONCLUSIONS

In our opinion, it is important to consider osteoid osteoma as a possible cause of otherwise unexplained pain of the hand or wrist. If there is clinical suspicion, we recommend the early use of gadolinium-enhanced MRI as a sensitive screening method. Thus, it should be possible to shorten the time interval until correct diagnosis is established.

New half-life measurement of 182Hf: improved chronometer for the early solar system

The decay of 182Hf, now extinct, into stable 182W has developed into an important chronometer for studying early solar system processes such as the accretion and differentiation of planetesimals and the formation of the Earth and the Moon. The only 182Hf half-life measurements available were performed 40 years ago and resulted in an imprecise half-life of (9+/-2)x10(6) yr. We redetermined the half-life by measuring the specific activity of 182Hf based on two independent methods, resulting in a value of t(1/2)(182Hf)=(8.90+/-0.09)x10(6) yr, in good agreement with the previous value, but with a 20 times smaller uncertainty. The greatly improved precision of this half-life now permits very precise intercalibration of the 182Hf-182W isotopic system with other chronometers.

Palmare winkelstabile Plattenosteosynthese der instabilen distalen Radiusfraktur

Internal fixation of distal radius fractures often shows the problem of secondary dislocation due to dorsal comminution and osteoporosis. Although dorsal plating systems provide good stabilization, the intraoperative control of reduction is difficult in the comminuted area with high incidence for the need of cancellous bone graft. Occurrence of extensor tendon complications including tendonitis and rupture is not uncommon. The use of fixed angle devices by a palmar approach has demonstrated the advantage of better visualization and control at the fracture side. The subchondrale support of the articular surface by fixed angle pegs or screws prevents secondary dislocation allowing early mobilization. Better soft tissue coverage is associated with a low complication rate. 62 patients (average age 55 years) were treated with different fixed angel devices according to the fracture type and underwent retrospective evaluation with mean follow-up of 11 months (6-23 months). According to the AO Classification there were 3 A2, 24 A3, 7 B3, 14 C1, 9 C2 und 5 C3 fractures. The majority beside the B3 types and one C3 fracture were dorsally displaced. All of them showed healing without relevant secondary loss of reduction. Mean DASH score reached 19 points.

[Structured concept for the establishment of a broad and ambulatory care of patients with type 2 diabetes: one-year evaluation of a regional teaching organization]

BACKGROUND

The increasing prevalence of diabetes mellitus and its long-term complications are associated with an expanding social medical problem. In order to originate an established teaching and training program on a physician-based level in short time, three specialist diabetes centers from Lübeck transferred their concept to a diabetes organization based on 17 physicians who had only rarely undertaken any diabetes teaching before. We investigated the achievement and effectiveness of this concept in a prospective multicenter evaluation one year after the patients had received structured diabetes teaching by the organization.

PATIENTS AND METHODS

Physicians and their teaching staff were trained by the specialists from the diabetes centers according to an official agreement. Patients were treated by each practice, while the diabetes teaching was done centrally by the organization through a diabetes assistant/dietician based on a modified official diabetes teaching and training program (ZI-program). 230 of 250 patients (120 male, 110 female) were reinvestigated one year after they had received the teaching. The group consisted of 179 non-insulin-treated (NIB; 94 via physicians, 85 via specialists) and 51 insulin-treated (IB; 19 via physicians, 32 via specialists) participants.

RESULTS

The average age of NIB was 60.4+/-9.8 years, while IBs were 68.8+/-7.3 years old. HbA (1c) values were reduced in both groups, NIB and IB, by approximately 1% (NIB: 7.59+/-1.97% to 6.59+/-1.84%; IB: 8.47+/-1.35% to 7,36+/-1,38 %; p < 0,001). In the NIB-group the BMI was reduced by 0,64+/-0,14 kg x m (-2), whereas it was increased in the IB-group by 0.33+/-0.24 kg x m(-2) (NIB: 30.55+/-0.40 to 29.91+/-0.39 kg x m(-2), p < 0.001; IB: 28.83+/-0.74 to 29.16+/-0.75 kg x m(-2), p = 0.82).

CONCLUSION

The transfer of established teaching and training concepts of specialist diabetes centers to a newly founded, physician-based diabetes organization resulted in a broad, effective and long-lasting medical care of patients with type 2 diabetics treated without or with insulin. The results are superior to those of other evaluations based on diabetes training ZI-programs.

Crystal structure of (1R*,2S*,5S*,6S*,7R*)-6-(3,5-dinitrobenzoyloxy)methyl-2,7-dimethyl-tricyclo [5.2.2.01,5]undec-8-ene, C21H24N2O6

C21H24N2O6, orthorhombic, P212121 (No. 19), a = 6.285(2) Å, b = 9.044(4) Å, c = 35.52(2) Å, V = 2019.0 Å3, Z = 4, R(F) = 0.095, wRref(F2) = 0.279, T = 295 K.

The HIV protease inhibitor indinavir impairs glycogen synthesis in HepG2 hepatoma cells

HIV protease inhibitor treatment is associated with insulin resistance. We have recently demonstrated that the HIV protease inhibitor indinavir influences initial insulin signaling steps in HepG2 cells. Here we investigated in the same cell model whether indinavir alters insulin-stimulated glycogen synthesis. Since an altered phosphotyrosine phosphatase activity could represent a mechanism by which insulin signaling is influenced, we also assessed potential indinavir effects on protein tyrosine phosphatase activity directed against tyrosine phosphorylated insulin receptor substrate-1. HepG2 cells were incubated for 48 h without or with indinavir (100 micro mol/l). Subsequently, the insulin-stimulated incorporation of 14C-glucose into glycogen was measured. In indinavir-treated cells the insulin effect on glycogen synthesis was reduced by 30 +/- 4.5 %. Dephosphorylation of immobilized tyrosine-phosphorylated insulin-receptor substrate-1 by the cell extracts was determined using a microwell plate-based method, and indinavir treatment did not alter this dephosphorylation. In conclusion, our data suggest that indinavir affects insulin-stimulation of glycogen synthesis in liver cells, and this may be related to the previously observed alterations in insulin signaling. Direct effects of indinavir on the GLUT4 transport system, that have been suggested from data in other cell systems, are unlikely in HepG2 cells that express no or almost no GLUT4 transport system. Finally, our data do not support the hypothesis that indinavir alters insulin signaling by influencing protein tyrosine phosphatase activity directed against insulin receptor substrate-1.

[Suicide attempt with insulin as a cause of myocardial infarct]

We report the case of a 31 year old healthy man without coronary risk factors, who made a suicide attempt with insulin caused by a chronic schizoid psychosis. The man was admitted to the hospital 14 hours later with non-specific chest pain and dizziness as clinical signs of a lateral wall myocardial infarction. The coronary angiography demonstrated intact coronary circulation and a broad area of myocardial damage of the left ventricular lateral wall. It is hypothesized that coronary artery vasospasm induced by hypoglycemia/hyperinsulinemia caused the myocardial infarction.

Angiotensin AT(1) receptor stimulates heat shock protein 27 phosphorylation in vitro and in vivo

The angiotensin type 1 receptor (AT(1)) exerts a variety of its signaling and cellular actions through its effects on protein phosphorylation. Phosphoproteomic analysis of angiotensin (Ang) II-stimulated aortic smooth muscle cells revealed that heat shock protein 27 (HSP27) represents a major protein phosphorylation target of the AT(1) signaling pathway. Stimulation of cells with Ang II resulted in 1.7-fold (P<0.05) and 5.5-fold (P<0.001) increases in HSP27 phosphoisoforms at pI 5.7 and pI 5.4, respectively. This was accompanied by a 54% (P<0.01) decrease in the nonphosphorylated HSP27 isoform, located at pI 6.4. Treatment of samples with alkaline phosphatase reversed this redistribution of HSP27 phosphoisoforms. Ang II-stimulated HSP27 phosphorylation was completely blocked by pretreatment of cells with the AT(1) antagonist CV11974. Phosphoamino acid analysis demonstrated that Ang II-induced phosphorylation of both HSP27 phosphoisoforms occurred exclusively on serine. Protein kinase C inhibition completely blocked phorbol ester-induced HSP27 phosphorylation but did not impair Ang II-stimulated phosphorylation of HSP27, suggesting that AT(1) increased HSP27 phosphorylation by a protein kinase C-independent pathway. Intrajugular infusion of Ang II in rats increased HSP27 in aorta by 1.7-fold (P<0.02), and this response was inhibited by CV11974. These results suggest that Ang II-induced HSP27 phosphorylation is a physiologically relevant AT(1) signaling event. Because serine phosphorylation of HSP27 blocks its ability to cap F-actin, Ang II/AT(1)-induced HSP27 phosphorylation may play a key role in actin filament remodeling required for smooth muscle cell migration and contraction.

Reply to: Econometric issues in testing the age neutrality of health care expenditure

Salas and Raftery allege that in our paper, (1) remaining life expectancy is an endogenous explanatory variable of health care expenditure and (2) the parameter designed to correct for sample selection bias in fact represents a hidden relationship between health care expenditure and age. We argue that claim (1) is not supported by the available empirical evidence, while claim (2) seems to derive from a too cursory reading of our paper.

Biotransformation of various substituted aromatic compounds to chiral dihydrodihydroxy derivatives

The biotransformation of four different classes of aromatic compounds by the Escherichia coli strain DH5alpha(pTCB 144), which contained the chlorobenzene dioxygenase (CDO) from Pseudomonas sp. strain P51, was examined. CDO oxidized biphenyl as well as monochlorobiphenyls to the corresponding cis-2,3-dihydro-2,3-dihydroxy derivatives, whereby oxidation occurred on the unsubstituted ring. No higher substituted biphenyls were oxidized. The absolute configurations of several monosubstituted cis-benzene dihydrodiols formed by CDO were determined. All had an S configuration at the carbon atom in meta position to the substituent on the benzene nucleus. With one exception, the enantiomeric excess of several 1,4-disubstituted cis-benzene dihydrodiols formed by CDO was higher than that of the products formed by two toluene dioxygenases. Naphthalene was oxidized to enantiomerically pure (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. All absolute configurations were identical to those of the products formed by toluene dioxygenases of Pseudomonas putida UV4 and P. putida F39/D. The formation rate of (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene was significantly higher (about 45 to 200%) than those of several monosubstituted cis-benzene dihydrodiols and more than four times higher than the formation rate of cis-benzene dihydrodiol. A new gas chromatographic method was developed to determine the enantiomeric excess of the oxidation products.

Identification of the gene altered in Berardinelli-Seip congenital lipodystrophy on chromosome 11q13

Congenital generalized lipodystrophy, or Berardinelli-Seip syndrome (BSCL), is a rare autosomal recessive disease characterized by a near-absence of adipose tissue from birth or early infancy and severe insulin resistance. Other clinical and biological features include acanthosis nigricans, hyperandrogenism, muscular hypertrophy, hepatomegaly, altered glucose tolerance or diabetes mellitus, and hypertriglyceridemia. A locus (BSCL1) has been mapped to 9q34 with evidence of heterogeneity. Here, we report a genome screen of nine BSCL families from two geographical clusters (in Lebanon and Norway). We identified a new disease locus, designated BSCL2, within the 2.5-Mb interval flanked by markers D11S4076 and D11S480 on chromosome 11q13. Analysis of 20 additional families of various ethnic origins led to the identification of 11 families in which the disease cosegregates with the 11q13 locus; the remaining families provide confirmation of linkage to 9q34. Sequence analysis of genes located in the 11q13 interval disclosed mutations in a gene homologous to the murine guanine nucleotide-binding protein (G protein), gamma3-linked gene (Gng3lg) in all BSCL2-linked families. BSCL2 is most highly expressed in brain and testis and encodes a protein (which we have called seipin) of unknown function. Most of the variants are null mutations and probably result in a severe disruption of the protein. These findings are of general importance for understanding the molecular mechanisms underlying regulation of body fat distribution and insulin resistance.

Protein kinase C activation and its pharmacological inhibition in vascular disease

Vascular complications in diabetes mellitus are known to be associated with the activation of the protein kinase C (PKC) pathway through the de novo synthesis of diacylglycerol (DAG) from glycolytic intermediates. Specific PKC isoforms, mainly the beta- and delta-isoforms, have been shown to be persistently activated in diabetic mellitus. Multiple studies have reported that the activation of PKC leads to increased production of extracellular matrix and cytokines, enhances contractility, permeability and vascular cell proliferation, induces the activation of cytosolic phospholipase A2 and inhibits the activity of Na+-K+-ATPase. These events are not only frequently observed in diabetes mellitus but are also involved in the actions of vasoactive agents or oxidative stress. Inhibition of PKC by two different kinds of PKC inhibitors - LY333531, a selective PKC-beta-isoform inhibitor, and vitamin E, d-alpha-tocopheron - were able to prevent or reverse the various vascular dysfunctions in vitro and in vivo. Clinical studies using these compounds are now ongoing to evaluate the significance of DAG-PKC pathway activation in the development of vascular complications in diabetic patients.

Number processing and mental calculation in school children aged 7 to 10 years: a transcultural comparison

Neuropsychological studies of dyscalculic patients show that arithmetical development is not a unidimensional process. In transcultural investigations, cultural, educational and linguistic factors might affect differently the various components of mathematical development. Four hundred and sixty schoolchildren aged 7 to 10 years from Brasilia, Brazil (n = 141), Paris, France (n = 160) and Zurich, Switzerland (n = 159) were asked to perform eleven number processing and calculation tasks. Chronological age, which was almost confounded in this study to educational level, had a strong effect on some tasks (knowledge of the written code of numbers, number comparison, mental calculation, problem solving), but only a slight effect on other tasks (counting dots, counting backwards, estimation). Also, linguistic factors and factors related to the socio-economic level of the family had different effects on the various components of calculation and number processing. Evidence from developmental studies has to be integrated into theoretical models of calculation and number processsing, which are presently based mainly on results from neuropsychological studies of dyscalculic patients.

Tracheobronchial stenosis in Keutel syndrome

In 1971 Keutel et al. described a new syndrome in two siblings presenting with peripheral pulmonary stenoses, brachytelephalangism, neural hearing loss and abnormal cartilage calcification. Recent investigations provided evidence that mutations in the gene encoding the human matrix GLA protein cause Keutel syndrome. With these new insights in the disease the symptomatology of Keutel syndrome was reassessed. The follow-up of the two siblings was studied by clinical and post mortem examination. As a new feature of Keutel syndrome tracheobronchial stenosis and concentric calcification of pulmonary, coronary, hepatic, renal, meningeal and cerebral arteries were described. Complementary to the results in molecular genetics the symptomatology of Keutel syndrome could be revised by clinical and post mortem examination.

Crystallization and preliminary X-ray diffraction analysis of the active core of human recombinant cystathionine beta-synthase: an enzyme involved in vascular disease

Cystathionine beta-synthase (CBS) is a unique heme enzyme that catalyzes a PLP-dependent condensation of serine and homocysteine to give cystathionine. Deficiency of CBS leads to homocystinuria, an autosomal recessively inherited disease of sulfur metabolism. A truncated form of CBS in which the C-terminal amino-acid residues have been deleted has been prepared. The truncated CBS subunits form a dimer, in contrast to the full-length subunits which form tetramers and higher oligomers. The truncated CBS yielded crystals diffracting to 2.6 A which belong to space group P3(1) or P3(2). This is the first comprehensive structural investigation of a PLP and heme-containing enzyme.

Two isoforms of trimming glucosidase II exist in mammalian tissues and cell lines but not in yeast and insect cells

We previously cloned glucosidase II and provided in vivo evidence for its involvement in protein folding quality control. DNA-sequencing of different clones demonstrated the existence of two isoforms of glucosidase II which differed by 66 nucleotides due to alternative splicing. The existence of two enzyme isoforms in various organs of pig and rat as well as human, bovine, rat, and mouse cell lines could be demonstrated by RT-PCR and Western blotting. Furthermore, the two isoforms of glucosidase II could be detected in embryonic and postnatal rat kidney and liver. In yeast, Saccharomyces cerevisiae, and in insects, Drosophila S2 cells, only one isoforms of the enzyme was detectable. The ubiquitous occurrence of the two glucosidase II isoforms in mammalian tissues and cell lines might be indicative of a special function of each isoform.

Design of a minimal protein oligomerization domain by a structural approach

Because of the simplicity and regularity of the alpha-helical coiled coil relative to other structural motifs, it can be conveniently used to clarify the molecular interactions responsible for protein folding and stability. Here we describe the de novo design and characterization of a two heptad-repeat peptide stabilized by a complex network of inter- and intrahelical salt bridges. Circular dichroism spectroscopy and analytical ultracentrifugation show that this peptide is highly alpha-helical and 100% dimeric tinder physiological buffer conditions. Interestingly, the peptide was shown to switch its oligomerization state from a dimer to a trimer upon increasing ionic strength. The correctness of the rational design principles used here is supported by details of the atomic structure of the peptide deduced from X-ray crystallography. The structure of the peptide shows that it is not a molten globule but assumes a unique, native-like conformation. This de novo peptide thus represents an attractive model system for the design of a molecular recognition system.