Serotonin transporter gene-linked polymorphic region: allele distributions in relationship to body weight and in anorexia nervosa

Several lines of evidence implicate a role for the serotonergic system in body weight regulation and eating disorders. The magnitude and duration of postsynaptic responses to serotonin (5-HT) is directed by the transport into and release from the presynaptic neuron. Recently, a common polymorphism of a repetitive element in the region of the serotonin transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR) was identified that results in a system of two common alleles. The activity of the 5-HTT, as measured in in vitro assays and in human lymphoblastoid cell lines, is dependent on the respective genotype. We thus hypothesized that this polymorphism is relevant for weight regulation in general and is possibly involved in the etiology of anorexia nervosa (AN). Allele frequencies and genotypes were determined in a total of 385 unrelated obese children, adolescents and adults, 112 underweight subjects and 96 patients with AN. Furthermore, both parents of 98 obese children and adolescents and of 55 patients with AN, respectively, were genotyped, thus allowing to test for both association and linkage. The comparison of allele frequencies between obese and underweight probands provided no evidence for a major role of the 5-HTTLPR in weight regulation. Patients with AN had allele frequencies not significantly different to those observed for obese and underweight individuals.

Epstein-Barr virus--Associated hemophagocytic syndrome. A cause of fever of unknown origin in human immunodeficiency virus infection

A 26-year-old human immunodeficiency virus-positive man presented with fever of unknown origin, pancytopenia, and elevated liver function tests. Numerous diagnostic tests and empiric therapeutic interventions remained unsuccessful. Splenectomy eventually established the diagnosis of Epstein-Barr virus-associated hemophagocytic syndrome. Treatment with foscarnet, acyclovir, prednisone, and vinblastine resulted in complete recovery. Three months later, Hodgkin's disease, a previously reported complication of the Epstein-Barr virus-associated hemophagocytic syndrome, was diagnosed. Fever, pancytopenia, and hepatic dysfunction are common complication of advanced human immunodeficiency virus infection and can be caused by a variety of opportunistic pathogens. A high index of suspicion is critical for the management of this otherwise fatal disorder because once the diagnosis is made, even patients with advanced disease benefit from aggressive therapeutic intervention, as demonstrated in the case presented.

[Heart rate variability in patients with sleep associated breathing disorders]

The increased mortality among patients with obstructive sleep apnoea syndrome has been explained in part by the increased incidence of pulmonary hypertension and coronary artery disease (CAD). A decreased heart rate variability has been shown to be associated with an increased mortality as well. We therefore screened 53 patients for sleep-related breathing disorders (SRBD) and heart rate variability (HRV) during the sleeping period. Standard time domain parameters were compared in a univariate multifactorial model for patients with an oxygen desaturation index (ODI) of more or less than 5 including the factors CAD, diabetes and beta-blocker use. The percentage of differences between RR-intervals that differ more than 50 ms (pNN > 50: 9.0 +/- 11.1% vs 19.2 +/- 22.2%; p < 0.05) as well as the root mean square of these differences (rMSSD: 38.0 +/- 29.0 msec vs 59.2 +/- 51.5 msec; p < 0.05) were significantly decreased in patients with SRBD. These results favour HRV for inclusion in future risk stratification models in patients with sleep-related breathing disorders.

Low body weight in male children and adolescents with schizoid personality disorder or Asperger's disorder

This study explored the hypothesis that body weight is reduced in male children and adolescents with schizoid personality disorder or Asperger's disorder. The body weights of 33 consecutively admitted male subjects with one of these disorders were retrospectively assessed with percentiles for the body mass index (BMI). The mean percentile (+/- SD) for the BMI was 31.6 +/- 27.6 and differed significantly from the expected value of 50 (P<0.001). Ten subjects had a BMI of < or = 10th age percentile. Post hoc comparisons revealed that BMI percentiles were (a) reduced to a similar extent in patients with schizoid personality disorder and Asperger's disorder and (b) reduced to a greater extent in patients with abnormal eating behaviour. During childhood and adolescence both diagnoses are associated with an increased risk of being underweight. Population-based BMI percentiles are useful for detecting associations between specific psychopathological syndromes and body weight.

Three-dimensional reconstitution of embryonic cardiomyocytes in a collagen matrix: a new heart muscle model system

A method has been developed for culturing cardiac myocytes in a collagen matrix to produce a coherently contracting 3-dimensional model heart tissue that allows direct measurement of isometric contractile force. Embryonic chick cardiomyocytes were mixed with collagen solution and allowed to gel between two Velcro-coated glass tubes. During culture, the cardiomyocytes formed spontaneously beating cardiac myocyte-populated matrices (CMPMs) anchored at opposite ends to the Velcro-covered tubes through which they could be attached to a force measuring system. Immunohistochemistry and electron microscopy revealed a highly organized tissue-like structure of alpha-actin and alpha-tropomyosin-positive cardiac myocytes exhibiting typical cross-striation, sarcomeric myofilaments, intercalated discs, desmosomes, and tight junctions. Force measurements of paced or unpaced CMPMs were performed in organ baths after 6-11 days of cultivation and were stable for up to 24 h. Force increased with frequency between 0.8 and 2.0 Hz (positive "staircase"), increasing rest length (Starling mechanism), and increasing extracellular calcium. The utility of this system as a test bed for genetic manipulation was demonstrated by infecting the CMPMs with a recombinant beta-galactosidase-carrying adenovirus. Transduction efficiency increased from about 5% (MOI 0.1) to about 50% (MOI 100). CMPMs display more physiological characteristics of intact heart tissue than monolayer cultures. This approach, simpler and faster than generation of transgenic animals, should allow functional consequences of genetic or pharmacological manipulation of cardiomyocytes in vitro to be studied under highly controlled conditions.

A highly sensitive cytotoxicity assay based on the release of reporter enzymes, from stably transfected cell lines

The well-established methods of generating stably transfected cell lines, and the detection of nanomolar amounts of an enzyme in a fast and reproducible assay, were utilised to establish non-radiometric cytotoxicity assays. In these assay systems, the detection of released enzymes was used to quantitate the leakage of intracellular proteins after membrane disintegration. Target cell lines were transfected with a luciferase reporter gene under the control of a strong eucaryotic promoter. Release of the intracellular expressed enzyme into the culture supernatant occurred after membrane perforation and was measured as an indicator of cellular death. The quantitation of released enzyme was a reliable indicator of cell death initiated either by complement-mediated killing, or by cell-mediated cytotoxicity. This system was initially established with P815 mastocytoma cells as an example of a target cell line. Transfection with the firefly luciferase gene provided an intracellular enzyme absent in mammalian cells. In a parallel approach, P815 and BW5147 target cells were transfected with bacterial beta-galactosidase to provide a similar cytotoxicity system. This enzyme, however, has a considerably longer half life in tissue culture medium than luciferase. In a direct comparison between the standard 51Cr release and beta-galactosidase release, the enzyme release showed a much higher signal-to-noise ratio, i.e., low background and high induced release if spontaneous release and detergent induced maximal lysis were measured. Since a wide range of human and murine cell lines can be stably transfected and several reporter genes are available, the system should provide an alternative for conventional cytotoxicity assays. The detection of released enzymes by colorimetric or luminometric methods makes this cytotoxicity assay independent of radionuclides. The sensitivity of luminometric enzyme detection systems should also permit the measurement of apoptotic processes and might make in vivo studies of cellular death using transgenic animals feasible.

[Effect of intraoperative blood loss on the function of natural killer cells in tumors of the upper gastrointestinal tract]

The activity of natural killer cells was measured perioperatively in 39 patients with esophageal and gastric cancer and was correlated with intraoperative blood loss. The activity of natural killer cells in all patients sank significantly (p < 0.05) on the fourth postoperative day to their original values. In the 24 patients with an intraoperative blood loss of more than 700 ml, the activity of the natural killer cells decreased significantly (p < 0.05) on the fourth postoperative day, in contrast to those 15 patients with an intraoperative blood loss of less than 500 ml; intraoperative blood loss and activity of natural killer cells show a correlation of R2 0.82.

Prediction of low body weight at long-term follow-up in acute anorexia nervosa by low body weight at referral

OBJECTIVE

The authors investigated the hypothesis that in acute anorexia nervosa a low body weight predicts a poor weight prognosis for the future.

METHOD

The body mass indexes at referral of 272 female patients were examined in relation to the body mass indexes of these patients after a mean follow-up of 9.5 years.

RESULTS

The overall correlation between body mass indexes at referral and at follow-up was r = 0.33. Despite this low correlation, the 100 patients with body mass indexes less than 13 kg/m2 at referral had low weights at long-term follow-up. Eleven of the 12 deceased patients were among these 100 patients, as were 24 of the 46 surviving patients whose body mass indexes were 17.5 kg/m2 or less at follow-up.

CONCLUSIONS

For patients with anorexia nervosa, a body mass index less than 13 kg/m2 at referral indicates a substantial risk for chronic anorexia nervosa and death related to emaciation.

Epidemiology of invasive mycosis in ICU patients: a prospective multicenter study in 435 non-neutropenic patients. Paul-Ehrlich Society for Chemotherapy, Divisions of Mycology and Pneumonia Research

OBJECTIVE

To determine the epidemiological and clinical significance of invasive fungal infections in non-neutropenic patients in intensive care who stay longer than 10 days on the intensive care unit (ICU).

DESIGN

Prospective epidemiological multicenter study over a period of 11 months, based on strict clinical, bacteriological, serological and histological criteria.

SETTING

Six surgical and two medical ICUs units in five university and two municipal hospitals.

PATIENTS

435 non-neutropenic patients from medical and surgical ICUs with an ICU stay of more than 10 days.

MEASUREMENTS AND MAIN RESULTS

A new occurrence of invasive mycosis (3 sepsis/4 peritonitis/1 disseminated candidiasis), corresponding to the protocol conditions with onset after day 10 in the ICU, was detectable in 2.0% (95% confidence interval 0.85 to 3.8%) of the 409 patients who could be assessed. Candida species were identified as an infection-relevant pathogen in all cases. The most important risk factor for the development of an invasive mycosis was the onset of peritonitis by the day 11 in the ICU (odds ratio 11.3; p = 0.003). A fungal colonization was detected in 64% of patients (Candida species 56%, Aspergillus 4%, and other fungi). Six of 8 patients with an invasive mycosis died on the ICU; ICU mortality in patients with fungal colonization was 31% and in noncolonized patients 26%. Serological tests were not helpful clinically. The sensitivity was 88% for the Candida HAT (haemagglutination test) (threshold titer > 1:160), 100% for the Candida IFT (immunofluorescence test) (threshold titer > 1:80), and 50% for the Candida Antigen Test (Candtec Ramco, threshold titer > or = 1:8), and the specificity was 26, 6, and 73%, respectively. The specificity for the Aspergillus HAT (threshold titer > 1:10) was 29%.

CONCLUSIONS

Invasive mycoses are rare in non-neutropenic ICU patients, even after a longer stay in the intensive care unit; fungal colonization, on the other hand, is frequently detectable. The mortality of invasive mycosis--even with systemic antimycotic therapy--was high; the mortality in patients with fungal colonization was not significantly increased compared to that in noncolonized patients. The serological test procedures, Candida HAT, Candida IFT, and the Candida Ramco Antigen Test, had a low specificity and were not helpful in diagnosing relevant invasive mycosis.

Beta 3-adrenergic-receptor allele distributions in children, adolescents and young adults with obesity, underweight or anorexia nervosa

OBJECTIVE

The missense mutation (64Trp to 64Arg) in the beta 3-adrenergic-receptor has previously been described to confer a genetic predisposition to the development of obesity.

DESIGN

To test the hypothesis we evaluated allele frequencies in children, adolescents and young adults who belonged to different weight groups that were delineated with percentiles for the body mass index (BMI; kg/m2).

SUBJECTS

99 underweight probands (BMI < or = 15th percentile). 80 normal weight probands (BMI: 5th-85th percentile). 238 obese children and adolescents (BMI > or = 97th percentile). 84 patients with anorexia nervosa (AN).

MEASUREMENTS

The cohorts were screened by polymerase chain reaction with subsequent restriction fragment length polymorphism (PCR-RFLP) analysis. Data were statistically analysed for association. In addition to these case control studies, the transmission disequilibrium test (TDT) was applied to 80 families of obese probands and to 52 families of patients with AN.

RESULTS

Both the tests for association and linkage were negative. The Trp64Arg allele frequencies in the three weight groups (obesity: 0.071; normal weight: 0.081; underweight: 0.056) and the AN patients (0.054) were similar. Extremely obese individuals showed no excess of the Trp64Arg allele. No homozygotes for the Trp64Arg allele were detected.

CONCLUSION

Heterozygosity for the Trp64Arg allele is not of major importance in regulation of body weight in individuals younger than 35 y. Additionally, the extreme obese subgroup is not enriched for the polymorphism.

Significant weight gains in a clinical sample of obese children and adolescents between 1985 and 1995

OBJECTIVE

Within the past decades prevalence rates for obesity among children and adolescents have increased in different populations. The hypothesis of this study is that the degree of adiposity in clinical study cohorts of extremely obese children and adolescents increased within the past decade.

DESIGN

In six different study cohorts of the time period from 1985-1995 body mass indices (BMIs) of obese children and adolescents who were treated as inpatients at a specialized children's hospital were evaluated. For this purpose body heights, body weights, ages and sex of all inpatients of three referring agencies were retrospectively assessed biannually.

RESULTS

In these six cohorts a significant BMI-increase from 1985-1995 of 1.9 kg/m2 (P < 0.0001) for constant sex, age and referring agencies was found: Comparisons of the quartiles and the ninth decline in both sexes did not show any systematic increase at the first quartile. In contrast, BMI-increases at the ninth decile were approximately 5 kg/m2 for males and 2.5 kg/m2 for females.

CONCLUSION

Within the decade studied a significant BMI-increase was detectable in this clinical population. This effect is especially discernible in the most extreme weight groups and in males.

Reduction of myocardial myoglobin in bovine dilated cardiomyopathy

Myoglobin levels are decreased in various animal models of heart failure, a change that has been associated with compromised energy supply. The underlying mechanisms by which myoglobin content decreases in failing myocardium are unknown. Bovine hereditary cardiomyopathy (bCMP) displays several characteristics of human dilated cardiomyopathy with a marked desensitization of the beta-adrenoceptor signal cascade. The aim of the present study was to investigate whether a similar reduction of myoglobin can be seen in this animal model, and to elucidate the possible mechanism of this reduction. Myoglobin protein concentration was decreased by 46-47% (P < 0.05) in left and right ventricular myocardium of failing hearts (n = 9) compared to control hearts (n = 11). No difference was found between atria of diseased and control animals. Immunohistochemistry with a polyclonal antibody against myoglobin revealed a strong and uniform labeling in cardiomyocytes of non-failing hearts. Using microscopic densitometry, immunosignals were significantly decreased in ventricular myocytes of bCMP hearts (168 +/- 5.3 v 118 +/- 8.6 arbitrary units, P < 0.05). Moreover, myoglobin was heterogeneously distributed in bCMP hearts, with single myocytes showing no staining. Slot blot analysis of total RNA demonstrated a 40-50% reduction (P < 0.05) of myoglobin mRNA levels in ventricular but not in atrial myocardium of bCMP hearts. The results support the view that a decrease of myocardial myoglobin is a general phenomenon in end-stage heart failure. It appears to be primarily due to reduced gene expression but may be aggravated by leaking from single myocytes. The decrease of myoglobin may contribute to the imbalance between energy production and energy expenditure in heart failure.

Sleep-related myocardial ischemia and sleep structure in patients with obstructive sleep apnea and coronary heart disease

STUDY OBJECTIVES

Patients with coronary heart disease (CHD) and obstructive sleep apnea may have an increased cardiac risk due to nocturnal myocardial ischemia triggered by apnea-associated oxygen desaturation. Sleep structure in patients with obstructive sleep apnea is fragmented by activation of the central nervous system (CNS) (arousal) due to obstructive apneas. Nocturnal myocardial ischemia may lead to activation of the CNS as well.

PATIENTS

Fourteen patients with obstructive sleep apnea and CHD disease and seven patients suffering from obstructive sleep apnea without CHD were studied. Overnight sleep studies and simultaneous six-lead ECG recordings were performed. In addition, sleep studies and ECG recordings were performed with administration of a sustained-release nitrate in these patients in a double-blinded crossover design.

RESULTS

Analysis of three nights' recordings revealed 144 episodes of nocturnal myocardial ischemia in six subjects. Five patients had underlying CHD and one patient exhibited diffuse wall defects of the coronary arteries; also, 85.4% of ischemic episodes were concomitant with apneas and oxygen desaturation > 3%, and 77.8% of ischemic episodes occurred during rapid eye movement (REM) sleep, although total amount of REM sleep was only 18% of total sleep time. Mean oxygen saturation was significantly lower (p < 0.05) during apnea-associated ischemic episodes than during nonapnea-associated ischemia (77.3% vs 93.1%). Nitrate administration did not reduce ischemic episodes. Sleep architecture (macrostructure) exhibited a reduction in sleep stages non-REM 3 and 4 and REM sleep. Comparing the microstructure of sleep (arousals) within episodes with and without ischemia but similar criteria like sleep stage, apnea activity, and oxygen saturation, we found significantly more (p < 0.01) and severe (p < 0.001) arousals during periods with myocardial ischemia than during control episodes. In addition, microstructure of sleep was disturbed by myocardial ischemia itself in absence of apneas.

CONCLUSION

It is concluded that patients with CHD and obstructive sleep apnea are endangered by apnea-associated ischemia and that these ischemic episodes lead to activation of the CNS and additional fragmentation of sleep. Patients with nocturnal ischemia should be screened for underlying sleep apnea even if nitrate therapy fails.

Role of transanal endoscopic microsurgery in the palliative treatment of rectal cancer

BACKGROUND

Palliative, minimal invasive treatment of rectal cancer is advocated in patients with advanced and incurable disease or poor clinical condition and in those who refuse radical surgery. Several methods have been used during recent years. We report our experience with palliative transanal endoscopic microsurgery.

MATERIALS

Between 1983 and 1995, 29 patients underwent transanal endoscopic microsurgery for palliation. Eleven patients had advanced malignant disease, nine were in poor clinical condition, and nine repeatedly refused radical surgery.

RESULTS

Intraoperatively one severe complication, an intra-abdominal perforation, occurred. The morbidity rate was 14%. Postoperatively, clinical signs were abolished or improved in all cases. Only three patients required further palliative resections after initial symptom relief.

CONCLUSIONS

Transanal endoscopic microsurgery is a successful approach in the palliative treatment of rectal cancer. The technique enables complete resection of rectal tumors. Although anesthesia is needed, the morbidity is low, even in patients with poor clinical condition.

Predictive diagnostic value of clinical assessment and nonlaboratory monitoring system recordings in patients with symptoms suggestive of obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSA) is of increasing importance because of its high prevalence and danger of morbidity to untreated patients. Diagnostic procedures need simplification. We evaluated the qualitative value of a stepwise diagnostic approach using clinical assessment and a home-based screening device according to current recommendations.

METHODS

We investigated 114 patients with symptoms suggestive of obstructive sleep apnea syndrome by means of their clinical features, questionnaire responses, four-channel nonlaboratory monitoring (NLM) and full polysomnography. Operative indices in the diagnosis of OSA were calculated.

RESULTS

A significant correlation (r = 0.7: p < 0.0001) was found between the oxygen desaturation index (ODI) and the respiratory disturbance index (RDI). The calculation of the difference between ODI by NLM and RDI by polysomnography showed a lack of agreement. Home-based monitoring revealed a high sensitivity (94%) but a low specificity (41%) in diagnosing OSA. However, a combination of clinical features, questionnaires and pulse oximetry achieved a specificity of 92%.

CONCLUSION

Home-based monitoring provides reasonable negative predictive values in the diagnosis of OSA syndrome in symptomatic patients. It therefore qualifies as a screening method. Combined with clinical features and questionnaires it provides high positive predictive values and may therefore prove useful in simplifying diagnostic procedures.

Post-approval drug research: objectives and methods

The limitations of pre-marketing clinical trials are analyzed and the need for ongoing drug research after approval is emphasized. Rare adverse drug reactions constitute the most important but not the only question. In addition to so-called post-marketing Drug Utilization Observation studies and spontaneous event reporting systems, other pharmacoepidemiologic study approaches like comparative cohort studies and case control studies, and also randomized clinical trials, are necessary to meet the multitude of scientific objectives of post-approval drug research.

Evaluation of a Cys23Ser mutation within the human 5-HT2C receptor gene: no evidence for an association of the mutant allele with obesity or underweight in children, adolescents and young adults

Serotonin is a neurotransmitter involved in a large number of psychophysiological processes including the regulation of mood, arousal, aggression, sleep, learning, nociceptions, nerve growth and importantly, appetitive functions. Alterations of 5-HT receptor activity have been shown to occur in many psychiatric diseases including depression, anxiety, eating disorders, schizophrenia etc. Hence, genetic variation in genes coding for serotonin receptor proteins might well be involved in the genetic predisposition to these diseases and therefore are of great pharmacogenetic relevance. Knockout mice deficient of a functional 5-HT2C receptor have implicated a potential role of this receptor subtype in the serotonergic control of appetite. A Cys23Ser mutation in the human 5-HT2C receptor gene discovered recently prompted us to investigate this mutation with regard to the development of human obesity. We have evaluated this mutation in 241 obese children and adolescents (mean BMI > or = 97th percentile), 80 normal weight children (BMI 5th-85th percentile) and 92 underweight probands (BMI < or = 15th percentile) for a possible association with obesity. The frequencies of the mutant allele in all three weight groups (obese subjects: 0.1597; normal weight: 0.168; underweight: 0.1575) were very similar. Association as well as linkage studies were negative. Therefore it is unlikely that this receptor mutation plays a direct role in the development of human obesity.

Identification of novel growth-related genes linked to the mitogenic effect of PACAP on the rat pancreatic acinar cell line, AR4-2J

The mRNA differential display technique was employed in order to identify novel growth-related genes linked to the mitogenic effect of PACAP on AR4-2J cells. Hereby, three differentially expressed and PACAP-inducible genes were found, one of these being homologous to a recently discovered putative growth-related early response gene in mice. In AR4-2J cells, mRNA levels of this novel rat gene are increased by PACAP in a rapid and transient fashion. This effect was enhanced by cycloheximide, whereas actinomycin D prevented the stimulatory effect of PACAP.

Pituitary adenylate-cyclase-activating polypeptide stimulates proto-oncogene expression and activates the AP-1 (c-Fos/c-Jun) transcription factor in AR4-2J pancreatic carcinoma cells

Pituitary adenylate-cyclase-activating polypeptide (PACAP) has been shown to possess mitogenic activity in various tumor cells. The present study was designed to investigate signal transduction mechanisms and expression of the proto-oncogenes c-fos and c-jun linked to the mitogenic effect of PACAP in the pancreatic carcinoma cell line AR4-2J. PACAP-(1-27)-peptide and PACAP-(1-38)-peptide, but not the structurally related vasoactive intestinal polypeptide (VIP), potently stimulated [3H]thymidine incorporation and cell number at doses of 0.1-10 nM. Both molecular forms of PACAP strongly increased formation of cAMP and inositol trisphosphate, elevated cytosolic Ca2+ levels and induced mitogen-activated protein (MAP) kinase activity. Quantitative reverse-transcription PCR revealed that PACAP-(1-27)-peptide and PACAP-(1-38)-peptide elevated c-fos mRNA levels 50-100-fold, whereas c-jun mRNA levels increased only moderately (2-3-fold). The effect of PACAP on c-fos and c-jun expression in AR4-2J cells was rapid (20 min), transient (1-2 h), dose-dependent IC50, 0.5 nM) and was abolished by the specific PACAP receptor antagonist PACAP-(6-38)-peptide or inhibitors of protein kinase C or tyrosine kinases. Compared with PACAP, epidermal growth factor and gastrin equipotently stimulated c-fos transcription whereas VIP, secretin, forskolin or phorbolester showed only marginal effects. Both PACAP (1-27)-peptide and PACAP-(1-38)-peptide strongly increased the DNA binding activity of the c-fos/ c-jun heterodimer transcription factor AP-1 at 10 nM and also stimulated AP-1 transcriptional activity up to 20-fold in AR4-2J cells. These findings indicate that the mitogenic effect of PACAP mediated via activation of the GTP-binding protein coupled PACAP/VIP-1 (PV1) receptor is linked to the MAP kinase cascade, increased expression of the proto-oncogenes c-fos and c-jun and activation of the heterodimeric transcription factor AP-1.