Multicentric pilot study to standardize clinical whole exome sequencing (WES) for cancer patients

A growing number of druggable targets and national initiatives for precision oncology necessitate broad genomic profiling for many cancer patients. Whole exome sequencing (WES) offers unbiased analysis of the entire coding sequence, segmentation-based detection of copy number alterations (CNAs), and accurate determination of complex biomarkers including tumor mutational burden (TMB), homologous recombination repair deficiency (HRD), and microsatellite instability (MSI). To assess the inter-institution variability of clinical WES, we performed a comparative pilot study between German Centers of Personalized Medicine (ZPMs) from five participating institutions. Tumor and matched normal DNA from 30 patients were analyzed using custom sequencing protocols and bioinformatic pipelines. Calling of somatic variants was highly concordant with a positive percentage agreement (PPA) between 91 and 95% and a positive predictive value (PPV) between 82 and 95% compared with a three-institution consensus and full agreement for 16 of 17 druggable targets. Explanations for deviations included low VAF or coverage, differing annotations, and different filter protocols. CNAs showed overall agreement in 76% for the genomic sequence with high wet-lab variability. Complex biomarkers correlated strongly between institutions (HRD: 0.79-1, TMB: 0.97-0.99) and all institutions agreed on microsatellite instability. This study will contribute to the development of quality control frameworks for comprehensive genomic profiling and sheds light onto parameters that require stringent standardization.

Guanylyl Cyclase A/cGMP Signaling Slows Hidden, Age- and Acoustic Trauma-Induced Hearing Loss

In the inner ear, cyclic guanosine monophosphate (cGMP) signaling has been described as facilitating otoprotection, which was previously observed through elevated cGMP levels achieved by phosphodiesterase 5 inhibition. However, to date, the upstream guanylyl cyclase (GC) subtype eliciting cGMP production is unknown. Here, we show that mice with a genetic disruption of the gene encoding the cGMP generator GC-A, the receptor for atrial and B-type natriuretic peptides, display a greater vulnerability of hair cells to hidden hearing loss and noise- and age-dependent hearing loss. This vulnerability was associated with GC-A expression in spiral ganglia and outer hair cells (OHCs) but not in inner hair cells (IHCs). GC-A knockout mice exhibited elevated hearing thresholds, most pronounced for the detection of high-frequency tones. Deficits in OHC input–output functions in high-frequency regions were already present in young GC-A-deficient mice, with no signs of an accelerated progression of age-related hearing loss or higher vulnerability to acoustic trauma. OHCs in these frequency regions in young GC-A knockout mice exhibited diminished levels of KCNQ4 expression, which is the dominant K⁺ channel in OHCs, and decreased activation of poly (ADP-ribose) polymerase-1, an enzyme involved in DNA repair. Further, GC-A knockout mice had IHC synapse impairments and reduced amplitudes of auditory brainstem responses that progressed with age and with acoustic trauma, in contrast to OHCs, when compared to GC-A wild-type littermates. We conclude that GC-A/cGMP-dependent signaling pathways have otoprotective functions and GC-A gene disruption differentially contributes to hair-cell damage in a healthy, aged, or injured system. Thus, augmentation of natriuretic peptide GC-A signaling likely has potential to overcome hidden and noise-induced hearing loss, as well as presbycusis.

Differential deletion of GDNF in the auditory system leads to altered sound responsiveness

Glial-derived neurotrophic factor (GDNF) has been proposed as a potent neurotrophic factor with the potential to cure neurodegenerative diseases. In the cochlea, GDNF has been detected in auditory neurons and sensory receptor cells and its expression is upregulated upon trauma. Moreover, the application of GDNF in different animal models of deafness has shown its capacity to prevent hearing loss and promoted its future use in therapeutic trials in humans. In the present study we have examined the endogenous requirement of GDNF during auditory development in mice. Using a lacZ knockin allele we have confirmed the expression of GDNF in the cochlea including its sensory regions during development. Global inactivation of GDNF throughout the hearing system using a Foxg1-Cre line causes perinatal lethality but reveals no apparent defects during formation of the cochlea. Using TrkC-Cre and Atoh1-Cre lines, we were able to generate viable mutants lacking GDNF in auditory neurons or both auditory neurons and sensory hair cells. These mutants show normal frequency-dependent auditory thresholds. However, mechanoelectrical response properties of outer hair cells (OHCs) in TrkC-Cre GDNF mutants are altered at low thresholds. Furthermore, auditory brainstem wave analysis shows an abnormal increase of wave I. On the other hand, Atoh1-Cre GDNF mutants show normal OHC function but their auditory brainstem wave pattern is reduced at the levels of wave I, III and IV. These results show that GDNF expression during the development is required to maintain functional hearing at different levels of the auditory system.

Switch of dimensionality of exciton diffusion in aggregates

The ultrafast exciton dynamics in J-aggregates of a perylene bisimide dye is investigated for temperatures down to 77 K revealing at low temperatures a decrease of the exciton mobility and a change in the dimensionality.

GC-B Deficient Mice With Axon Bifurcation Loss Exhibit Compromised Auditory Processing

Sensory axon T-like branching (bifurcation) in neurons from dorsal root ganglia and cranial sensory ganglia depends on the molecular signaling cascade involving the secreted factor C-type natriuretic peptide, the natriuretic peptide receptor guanylyl cyclase B (GC-B; also known as Npr2) and cGMP-dependent protein kinase I (cGKI, also known as PKGI). The bifurcation of cranial nerves is suggested to be important for information processing by second-order neurons in the hindbrain or spinal cord. Indeed, mice with a spontaneous GC-B loss of function mutation (Npr2^cn/cn ) display an impaired bifurcation of auditory nerve (AN) fibers. However, these mice did not show any obvious sign of impaired basal hearing. Here, we demonstrate that mice with a targeted inactivation of the GC-B gene (Npr2 ^lacZ/lacZ , GC-B KO mice) show an elevation of audiometric thresholds. In the inner ear, the cochlear hair cells in GC-B KO mice were nevertheless similar to those from wild type mice, justified by the typical expression of functionally relevant marker proteins. However, efferent cholinergic feedback to inner and outer hair cells was reduced in GC-B KO mice, linked to very likely reduced rapid efferent feedback. Sound-evoked AN responses of GC-B KO mice were elevated, a feature that is known to occur when the efferent axo-dendritic feedback on AN is compromised. Furthermore, late sound-evoked brainstem responses were significantly delayed in GC-B KO mice. This delay in sound response was accompanied by a weaker sensitivity of the auditory steady state response to amplitude-modulated sound stimuli. Finally, the acoustic startle response (ASR) - one of the fastest auditory responses - and the prepulse inhibition of the ASR indicated significant changes in temporal precision of auditory processing. These findings suggest that GC-B-controlled axon bifurcation of spiral ganglion neurons is important for proper activation of second-order neurons in the hindbrain and is a prerequisite for proper temporal auditory processing likely by establishing accurate efferent top-down control circuits. These data hypothesize that the bifurcation pattern of cranial nerves is important to shape spatial and temporal information processing for sensory feedback control.

Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets

We report on recent experimental results deploying a continuous cryogenic hydrogen jet as a debris-free, renewable laser-driven source of pure proton beams generated at the 150 TW ultrashort pulse laser Draco. Efficient proton acceleration reaching cut-off energies of up to 20 MeV with particle numbers exceeding 109 particles per MeV per steradian is demonstrated, showing for the first time that the acceleration performance is comparable to solid foil targets with thicknesses in the micrometer range. Two different target geometries are presented and their proton beam deliverance characterized: cylindrical (∅ 5 μm) and planar (20 μm × 2 μm). In both cases typical Target Normal Sheath Acceleration emission patterns with exponential proton energy spectra are detected. Significantly higher proton numbers in laser-forward direction are observed when deploying the planar jet as compared to the cylindrical jet case. This is confirmed by two-dimensional Particle-in-Cell (2D3V PIC) simulations, which demonstrate that the planar jet proves favorable as its geometry leads to more optimized acceleration conditions.

Biphasic aggregation of a perylene bisimide dye identified by exciton-vibrational spectra

The quantum efficiency of light emission supramolecular aggregates strongly depends on the intermolecular coupling. We present a molecule which demonstrates two different aggregated structures with high and low quantum efficiency. The spectral signatures can be understood by simulating the aggregated structures and the corresponding exciton-vibrational spectra.

[Effect of body position on coordination of breathing and swallowing]

BACKGROUND

To allow passage of food, the swallowing process closes off the larynx and interrupts respiratory flow. Both the timing of the interruption of respiratory flow and the body position can affect the results of the swallowing process.

OBJECTIVE

The effect of body position on the swallowing process and the coordination of breathing and swallowing is investigated.

MATERIALS AND METHOD

A combined EMG/bioimpedance measurement system and a piezoelectric sensor were used to investigate coordination of breathing and swallowing of a range of food consistencies in three different body positions (90°, 45° and 0°) in healthy subjects.

RESULTS

Investigations were carried out on 21 healthy subjects (12 ♂, 9 ♀). 762 swallows were recorded. Changing body position was found to have a statistically significant effect on swallow-related parameters (maximum laryngeal elevation and speed of laryngeal elevation) and breathing pattern (pre- and post-swallow breathing phases). The laryngeal elevation as well as the speed of the laryngeal elevation is influenced significantly by the consistency to be swallowed. The breathing pattern changes from saliva to solid food of inspiration/swallow/inspiration to expiration/swallow/expiration. A change of body position influences the parameters specific for swallowing and the breathing patterns significantly.

CONCLUSIONS

This study demonstrates that body position affects coordination of breathing and swallowing and swallow-related parameters in healthy subjects. Our results indicate that patients should be enabled to adopt a position in which they are sitting at an angle of at least 45°.

Investigation of the suitability of tissue phantoms for testing the constancy of ultrasonic transducer arrays in quality assurance

PURPOSE

To ensure high quality ultrasound diagnostics, proper functioning of the devices used is a necessary prerequisite. Ultrasound transducers have proven to be the most failure-prone part of the signal chain. Their technical monitoring is possible in principle with the help of tissue phantoms. The background of the present study is to determine which type of phantoms and which measurement parameters are best suited to a consistency test as part of routine quality assurance of ultrasound imaging systems.

MATERIALS AND METHODS

A classic wire-type phantom (ATS Mod. 539, ATS Labs Bridgeport, USA) and a 3 D cyst phantom (TCC, Timelkam, Austria) were used for the studies and comparative tests were conducted between intact transducers and those in which faults had been simulated. The collected measurement data show a relatively large scatter. Therefore, statistical analysis methods were used, and the discrimination analysis proved to be a useful tool.

RESULTS

Local failures which arise, e. g. due to the breakdown of individual piezoelectric elements or element groups in the transducer array, can be detected with the help of the gray value targets of the ATS phantom, but only in those cases in which the error-affected sound field part actually overlaps with the target under consideration. The TCC phantom is not suitable for the detection of such errors. Global transducer failures, i. e. those that affect the entire array, can even be detected with both types of phantoms.

CONCLUSION

When the emphasis of quality assessment is on the detection of local defects in the array that make up the largest part of the transducer faults, studies with conventional phantoms are only of limited value.

Real-time computation of subdiffraction-resolution fluorescence images

In the recent past, single-molecule based localization or photoswitching microscopy methods such as stochastic optical reconstruction microscopy (STORM) or photoactivated localization microscopy (PALM) have been successfully implemented for subdiffraction-resolution fluorescence imaging. However, the computational effort needed to localize numerous fluorophores is tremendous, causing long data processing times and thereby limiting the applicability of the technique. Here we present a new computational scheme for data processing consisting of noise reduction, detection of likely fluorophore positions, high-precision fluorophore localization and subsequent visualization of found fluorophore positions in a super-resolution image. We present and benchmark different algorithms for noise reduction and demonstrate the use of non-maximum suppression to quickly find likely fluorophore positions in high depth and very noisy images. The algorithm is evaluated and compared in terms of speed, accuracy and robustness by means of simulated data. On real biological samples, we find that real-time data processing is possible and that super-resolution imaging with organic fluorophores of cellular structures with approximately 20 nm optical resolution can be completed in less than 10 s.

[Operative technique and outcome in metabolic surgery: conventional and banded gastric bypass]

BACKGROUND

The prevalence of morbid obesity and its sequelae is increasing in Germany, Europe and worldwide. Bariatric surgery is thus gaining in importance for the treatment of patients with malignant obesity. Creation of a gastric bypass is one of the most frequently performed procedures for obesity.

DISCUSSION

The gastric bypass has been used -since 1966 as a surgical means of weight reduction in obese patients. In the mean time various modifications have been developed. Thus, for example, the laparoscopic procedure represents the current standard. After the operation most patients experience an excess weight loss (EWL) of between 61 and 83 %. The comorbidities of obesity are also markedly improved and in a high percentage even cured after the operation. It is worthy of note that diabetes mellitus type II improves shortly after the operation even before any weight loss has occurred. The suggests that the operation induces more than "just" a loss of weight.

CONCLUSION

For decades the gastric bypass has been a well known standard operation of overweight and, in addition to the reduction in weight, is also a therapy for diabetes mellitus -type II.

Perceptions and beliefs about cough and tuberculosis and implications for TB control in rural Rwanda

SETTING

Two southern provinces of Rwanda, Butare and Gikongoro.

OBJECTIVES

To identify beliefs and popular perceptions on cough and tuberculosis (TB) in rural Rwanda and determine how they shape health-seeking behaviour.

METHODS

Eight focus group discussions, 21 key informant interviews and 12 illness narratives were conducted between May and June 2004.

STUDY POPULATION

TB patients, community members, traditional healers and health workers.

RESULTS

There is wide use of herbal treatment for chronic cough in Rwanda. Patients seek conventional care when alternative treatment options fail or when severe symptoms such as shortness of breath, bloody sputum and weight loss appear. There are several local illnesses associated with chronic cough, with different alternative treatments. TB symptoms are often mistaken for the acquired immune-deficiency syndrome (AIDS). Identified causes for cough-related illnesses can be classified as biomedical (germs, internal body dysfunction and worms), environmental (seasonal changes and dust), cultural (inheritance), socio-economic (hard work, malnutrition and tobacco), and supernatural (witchcraft). Three health-seeking end points emerge for chronic cough: home care, health facility and the traditional healer. Healers in some areas, however, believe TB due to witchcraft can only be treated traditionally.

CONCLUSION

This study unveils beliefs and treatment options for chronic cough in Rwanda, with important implications for TB control that should be addressed.

Presence of 14Hz spindle oscillations in the human EEG during deep anesthesia

OBJECTIVE

To report on presence of human EEG spindle oscillations on the cortical level within flat periods of the burst-suppression pattern during propofol-induced anesthesia; to search for corresponding oscillations and possible functional connections.

METHODS

Artefact-free epochs of spindle activation were selected from the electroencephalograms of opiate-dependent patients undergoing rapid opiate detoxification. Power spectral analysis and source localization using low-resolution-brain-electromagnetic-tomography (LORETA(Key)) were performed.

RESULTS

Sinusoidal rhythms with waxing and waning amplitudes appeared after propofol-induced narcosis but no direct correlations could be determined between individual dosage and characteristic spindle attributes. The power maximum stood midline over the cortical areas, especially around C(z). We calculated a peak frequency of 14(+/-1.2) Hz. Motor fields, particularly in the frontal, parietal, and various cingulate areas, were found to be the primary sources of spindle oscillations in the cortex.

CONCLUSIONS

The frequent occurrence of these localized spindle sources demonstrates the preference for motor fields. Spindle oscillations observed during propofol-induced narcosis were similar in frequency and shape to those observed in natural sleep.

SIGNIFICANCE

The results lend support to models that postulate a close link between the motor system and the organization of behavior. In addition, spindle rhythms under propofol bore some resemblance to spindle types which occur during sleep.

Post-training quality of syndromic management of sexually transmitted infections by chemists and druggists in Pokhara, Nepal: is it satisfactory?

OBJECTIVE

Using simulated client and provider interview methods, this study assessed chemists and druggists' post-training management quality of syndromic sexually transmitted infections focusing on the areas of privacy maintaining, encouraging, history taking, counseling, referral practice, partner notification, and drug prescribing and then compared the findings of two methods.

DESIGN

Forty-five pharmacies from a list of 75 in Pokhara, who collected sexually transmitted infections data during 1999, were selected randomly. First simulated client successfully presented either urethral or vaginal discharge syndrome at 37 pharmacies and recorded the events of whole encounter into an observation form within 20 minutes. Later 39 chemists and druggists were interviewed by a pre-tested semi-structured questionnaire.

MAIN MEASURE

Results were reported mainly by numbers and corresponding percentages. For comparative purpose, P values were also shown.

RESULTS

Overall, interview method revealed satisfactory knowledge of chemists and druggists for management of sexually transmitted infections except drug prescribing but their actual behaviors, revealed by simulated client method, indicated lower quality and differed significantly in the areas of encouraging, history taking, counseling, referral practice, and partner notification. Both methods indicated very poor qualities of drug prescribing.

CONCLUSION

Retained knowledge of chemists and druggists for syndromic management of sexually transmitted infections were not applied to simulated client in actual practice. They should not prescribe drugs for patients of sexually transmitted infections, except referring to the doctors/hospitals. Continuous monitoring and further motivations for them may improve syndromic management quality of sexually transmitted infections. Moreover, depending on the purpose of study, various methods should be applied simultaneously to reach a better conclusion.

Comparative prospective study on splint therapy of anterior disc displacement without reduction

A prospective randomized study was carried out to compare the therapeutic success of two different types of splint in patients with painful anterior disc displacement of the temporomandibular joint. The patients in Group I (n = 20) received stabilization splint therapy and the patients in Group II (n = 20) pivot splint therapy. Clinical investigation of the craniomandibular system was performed before and 1, 2 and 3 months after therapy and this was accompanied by subjective evaluation by the patients of their symptoms, using a validated questionnaire with visual analogue scales (VAS). There was a significant increase in maximum jaw opening and a significant reduction in subjective pain in both groups during the course of therapy (Wilcoxon test, P < 0.05). Active jaw opening increased by a mean of 8.05 mm in the group of patients treated with a stabilization splint (Group I). The comparable figure with pivot splint therapy (Group II) was 8.26 mm. The VAS scale value in Group I was reduced by 30.54 units and in Group II by 39.36 scale units. However, neither of these differences between the groups was statistically significant (Mann-WhitneyU-test, P > 0.05). It can be concluded that both types of splint provided effective therapy in patients with anterior disc displacement.

The Patient State Index as an indicator of the level of hypnosis under general anaesthesia

BACKGROUND

This retrospective study describes the performance of the Patient State Index (PSI), under standard clinical practice conditions. The PSI is comprised of quantitative features of the EEG (QEEG) that display clear differences between hypnotic states, but consistency across anaesthetic agents within the state.

METHODS

The PSI was constructed from a systematic investigation of a database containing QEEG extracted from the analyses of continuous 19 channel EEG recordings obtained in 176 surgical patients. Induction was accomplished with etomidate, propofol, or thiopental. Anaesthesia was maintained by isoflurane, desflurane, or sevoflurane, total i.v. anaesthesia using propofol, or nitrous oxide/narcotics. It was hypothesized that a multivariate algorithm based on such measures of brain state, would vary significantly with changes in hypnotic state.

RESULTS

Highly significant differences were found between mean PSI values obtained during the different anaesthetic states selected for study. The relationship between level of awareness and PSI value at different stages of anaesthetic delivery was also evaluated. Regression analysis for prediction of arousal level using PSI was found to be highly significant for the combination of all anaesthetics, and for the individual anaesthetics.

CONCLUSIONS

The PSI, based upon derived features of brain electrical activity in the anterior/posterior dimension, significantly co-varies with changes in state under general anaesthesia and can significantly predict the level of arousal in varying stages of anaesthetic delivery.

EEG controlled rapid opioid withdrawal under general anaesthesia

We performed rapid opioid detoxification under propofol anaesthesia in 30 opioid addicts, using the opioid receptor antagonist naltrexone. Two strategies to obtain a sufficient depth of anaesthesia and to avoid anaesthetic overdose were evaluated. Patients were allocated randomly to one of two groups. In group 1, the effects of propofol were monitored by observing clinical signs, and in group 2, depth of anaesthesia was controlled using an EEG threshold method. Withdrawal symptoms and post-anaesthetic recovery time were assessed. All patients remained stable and no anaesthetic complications were noted. There were significant differences in the total dose of propofol given (group 1, mean 72 (SD 9) mg kg-1; group 2, 63 (8) mg kg-1; P < 0.01), duration of anaesthesia (318 (53) min vs 309 (42) min; P < 0.05), duration of recovery time (49 (13) min vs 40 (12) min; P < 0.01) and frequency of withdrawal symptoms between groups. In addition, the incidence of side effects was different between groups (62 vs 29 points on a withdrawal symptom scale; P < 0.01). To obtain a sufficient depth of anaesthesia but to avoid inappropriately large doses of anaesthetic, we consider that EEG monitoring is valuable during rapid opioid detoxification.

Effect of estradiol on insulin secreting INS-1 cells overexpressing estrogen receptors

BACKGROUND

Estrogen has been shown to have profound effects on insulin and glucose metabolism in vivo. Indeed, estrogens were recently shown to modulate ion channel and secretory activities in endocrine cells.

DESIGN AND METHODS

To investigate whether estrogenic influences are caused by direct effects on pancreatic beta-cells, we equipped INS-1 insulinoma cells with estrogen receptors and monitored insulin content and Ca(2+) fluxes as well as basal and stimulated insulin secretion upon different stimuli including glucose, the Ca(2+) ionophore ionomycin, the Ca(2+) channel agonist BayK8644, the protein kinase C activator TPA, and the adenylate cyclase activator forskolin.

RESULTS AND CONCLUSION

Our data reveal that estradiol has no significant direct effect on proliferation rate, insulin content, basal and stimulated insulin output as well as Ca(2+) fluxes of insulin secreting cells in vitro, indicating that in vivo responses to estrogen on insulin and glucose metabolism result from indirect betacytotropic effects.

The human mandibular intercondylar angle measured by computed tomography

In axial computed tomography it is possible to measure the intercondylar angle at the intersection of the longitudinal axes of the condyles. Published values range from 131 to 165 degrees. This angle was determined here in two groups of patients with (n = 22) and without (n = 12) temporomandibular joint dysfunction. A third group of children (n = 12) aged 4-9 years was included to investigate any age-related change in the angle. In the group of healthy individuals, a range of 105 to 165 degrees was found, with a mean intercondylar angle of 139 degrees. In the group with temporomandibular joint dysfunction the mean angle was 143 degrees with a range from 85 to 170 degrees. No statistically significant relation could be shown between intercondylar angle and joint dysfunction. In the group of children the mean angle was 138 degrees with values ranging from 90 to 180 degrees. No significant differences could be demonstrated among the groups. The absolute value of the intercondylar angle seems to be independent of factors such as sex, age and functional disorders of the joint.

Nephrogenic adenoma: A rare bladder tumor in children

OBJECTIVE

Nephrogenic adenomas of the urinary bladder are rare benign tumors in children. The purpose of our study was to obtain information about the sex distribution, presenting symptoms, intravesical locations, therapy and recurrence rates in pediatric nephrogenic adenomas.

PATIENTS AND METHODS

The records of 3 children with nephrogenic adenoma of the urinary bladder diagnosed between 1990 and 1997 were reviewed to evaluate the initial symptomatology, diagnostic examinations and findings, therapeutic procedures and clinical outcome and recurrence rates. Furthermore our data are compared to the findings of all children reported in the literature.

RESULTS

Including the 3 cases reported by us, the data on 18 children with nephrogenic adenoma of the bladder could be analyzed. There was a significant predominance of girls compared to boys (5:1); the medical history in all cases was remarkable for previous bladder surgery 3 months to 7 years prior to tumor diagnosis. Most children presented with unspecific symptoms of gross hematuria, dysuria and bladder instability and in all cases the final diagnosis was established after cystoscopy and histopathologic review of a tumor biopsy specimen. Therapy consisted of transurethral resection in 15 cases, partial cystectomy and open excision in 2 and 1 case, respectively. Tumor recurrence developed in 80% of the children with a latency period of 4 years.

CONCLUSIONS

Nephrogenic adenomas represent an epithelial response of the urothelium to chronic inflammation or previous trauma resulting in urothelial metaplasia and the development of papillary lesions. Current treatment of choice consists of transurethral resection and fulguration of the base of the tumor and periodic cystoscopy.

Effects of elevated carbon dioxide environment on calcium metabolism in humans

BACKGROUND

Chronic respiratory acidosis induced by an elevated carbon dioxide (CO2) environment should provoke hypercalciuria with related total body and subsequent bone calcium losses. We examined this hypothesis in four healthy male volunteers, who were exposed during a 25-d period to an 0.7% CO2 environment within a deep diving isolation chamber. Three months later the same subjects were reexamined during a second campaign being exposed to a 1.2% CO2 atmosphere.

METHODS

The subjects received a constant calcium intake (1.4 g.d-1) and vitamin D supplement (1000 IU.d-1) during both campaigns. Calcium balance (oral calcium intake minus urinary and fecal calcium output) was evaluated. Serum calcium concentrations and biomarkers of bone metabolism were measured, in order to evaluate bone turnover. Additionally, the response to an acute oral calcium load was examined as a sensitive measure of changes in calcium metabolism.

RESULTS

Both, urinary calcium excretion (from 245 +/- 38 to 199 +/- 31 mg.d-1; mean +/- SE, 0.7% and 1.2%, respectively) and fecal calcium losses (from 1229 +/- 128 to 996 +/- 62 mg.d-1) were significantly reduced in the higher (1.2%) CO2 atmosphere. Although more calcium was retained in the body during the 1.2% than during the 0.7% CO2 campaign, serum calcium concentrations and biomarkers of bone formation were significantly lower in the higher CO2 campaign. Furthermore, bone resorption was slightly increased in the 1.2% experiment.

CONCLUSION

Elevated CO2 atmosphere may dose-dependently preserve body calcium without a parallel improvement of bone substance.

Insulinoma cells contain an isoform of Ca2+/calmodulin-dependent protein kinase II delta associated with insulin secretion vesicles

The Ca2+/calmodulin dependent protein kinase II (CaM kinase II) is thought to play an important part in glucose-stimulated insulin secretion. To determine which of the known subtypes (alpha, beta, gamma, delta) occur in insulin-secreting cells, we amplified all types of CaM kinase II by RT-PCR and found the beta3-, gamma-, delta2- and delta6-subtypes in RINm5F insulinoma cells. None of the other 8 delta-subtypes was present. Antibodies generated against the bacterially expressed association domain of the delta2-subtype recognized the recombinant gamma and delta-subtypes. In INS-1 and RINm5F cells, as well as freshly isolated rat islets, only a 55-kDa protein corresponding in size to the delta2-subtype expressed in NIH3T3 fibroblasts was detected. The delta2-subtype therefore appears to represent the predominant subtype of CaM kinase II present in insulin secreting cells. The enzyme was primarily associated with cytoskeletal structures, and very little was present in the soluble compartment or detergent soluble fraction in INS-1- or RINm5F-cells. An analysis of its subcellular distribution was performed by sucrose and Nycodenz density gradient fractionation of INS-1 cells and detection of CaM kinase II delta by immune blots. The enzyme codistributed with insulin used as a marker for secretory granules but not with the lighter synaptic-like microvesicles detected with an antibody against synaptophysin, plasma membranes (syntaxin 1), lysosomes (arylsulfatase), or mitochondria (cytochrome c oxidase). CaM kinase II delta2 thus is identified as the subtype associated with insulin secretory granules and is likely to be involved in insulin secretion.

Primary nocturnal enuresis and desmopressin treatment: do psychosocial factors affect outcome?

Twenty-three patients (5 to 15 years of age) with primary nocturnal enuresis were treated with desmopressin (DDAVP) according to a four-step protocol with weekly reductions of daily doses (1 to 0.25 microgram/kg body weight) thus including aspects of behavior-oriented "bladder retention training". The rate of wet nights was significantly reduced while patients were on medication (p < 0.02), but the sample as a whole returned to baseline levels after medication was stopped. Six subjects (26%) were non-responders. A variety of psychological and psychosocial single factors did not significantly affect the outcome. However, a subgroup of seven patients assessed as "psychologically non-distressed" revealed better results both on medication (p < 0.02; reduction 73%) and off medication (p > or = 0.05; reduction 39%) compared to a "distressed" subgroup (N = 16). Both groups showed significant changes in wet nights over the treatment course (p < 0.02 and p > or = 0.002, respectively). There was no clear-cut relationship between laboratory data (urine volume, osmolality, vasopressin) and outcome in wet nights. Data did not suggest a subgroup of patients with particularly low nocturnal vasopressin (AVP) secretion and, thus, high rates of wet nights. Our results corroborated the finding that DDAVP is an effective substance in reducing wet nights in patients with primary nocturnal enuresis. However, with respect to major reductions and long-term results (off medication), these preliminary findings suggest that "psychological distress" seems to be a very important confounding outcome variable. Thus, careful consideration and assessment of psychological and psychosocial aspects of distress are recommended. Eventually, a combination of DDAVP treatment with counseling and/or psychotherapy may significantly improve results for the majority of patients and families.

Possibilities of classification of topographically distributed neurophysiological multi-channel data

Progress in quantifying states of cerebral function and in the further development of automated EEG processing demands the application of suitable methods for the reduction of neurophysiological multi-channel data as well as their automatic classification. The method used here for reducing multi-channel data was to gain distributions of parametric descriptors from EEG data from computer-aided topographic electroencephalometry (CATEEM), for example the relative and absolute band power in the frequency bands delta, theta, alpha 1, alpha 2, beta 1, beta 2, total power, median and mode frequency, and other parameters. These values were subjected to cluster analysis. The classification of EEG parameters was carried out by means of discrimination analysis and neural networks. The practicability of both procedures was demonstrated in the reduction and classification of EEG data in the context of a normed study involving 104 healthy adults. These data have been used as the basis for a new evaluation study of 60 additional intraoperative EEG recordings obtained with CATEEM. In that newly started study, the effects of sedative and anaesthetic drugs on EEG behavior and psychophysiologic behavior remain to be investigated.

[Clinical significance of immunoscintigraphy for the diagnosis and treatment of gastrointestinal malignant tumors]

Eighty-one immunoscintigraphy (IS) studies in 80 patients with gastrointestinal malignancies were re-evaluated retrospectively to analyze accuracy and clinical impact of the IS findings. Selection of patients was based upon complete diagnostic records and a clinical follow-up of at least 6 months. The 3 antibody preparations used (99m-Tc labelled complete anti-CEA antibodies (BW 431/26), 111-In labelled F(ab')2-fragments against CEA (BW 431/31), and a mixture of 131-I labelled F(ab')2-fragments against CEA and CA 19-9 (IMACIS-1] yielded equal diagnostic sensitivities (65%, range 60-78%) except for liver metastases. These were preferably detected by the 131-I labelled compound. Best results were gained in local recurrencies of gastrointestinal cancer (12/15 true positive = 80%). Among these were 3 out of the 4 lesions which had been exclusively recognized by IS. Thus IS should be applied in patients with suggested local recurrencies and inconclusive outcome of routine diagnostic workup. A widespread and frequent use of IS (e.g. screening of metastases) cannot be advocated since diagnostic results were not convincing and the immunologic risks of IS (development of human anti-mouse antibodies) are still under discussion.

Influence of diet on 1,2-dimethylhydrazine metabolism in rat liver

The metabolism of 1,2-dimethylhydrazine (DMH) was investigated in isolated perfused livers excised from Sprague-Dawley rats fed four semisynthetic diets over two generations. The diets were varied within normal physiological limits, without producing specific deficiencies. Diet was shown to have an influence on the growth of animals and on the cholesterol content and beta-glucuronidase activity in the blood serum. However, diet did not influence the rate of metabolism of DMH or the concentration of metabolites.

Metabolism of 1,2-dimethylhydrazine in isolated perfused rat liver

The metabolism of 1,2-dimethylhydrazine (DMH) was investigated in isolated perfused rat liver. The separation of [14C]DMH and its metabolites azomethane (AM), azoxymethane (AOM) and methylazoxymethanol (MAM) was performed by high pressure liquid chromatography (HPLC). The fractions were quantitatively detected by liquid scintillation counting of the radioactivity. It was demonstrated that DMH is highly metabolized by the liver. After 1 h of perfusion, the median amounts of DMH and its metabolites in the medium were: DMH, 16%; AM, 3%; AOM, 42%; MAM, 30% of the given dose. During this time 9.9% and 0.7% of the total radioactivity were eliminated as AM and CO2 in the oxygen stream of the perfusion apparatus; 0.6% were excreted by bile and 12.3% stored in hepatic tissue. The reaction rate (t1/2) of each individual metabolic step was estimated by means of a mathematical kinetic model as follows: DMH leads to AM, 21.8 min; AM leads to AOM, 1.5 min; AOM leads to MAM, 41.5 min; MAM leads to, 611 min. The results are discussed in comparison to in vivo experiments.

Cell cycle-dependent replication of the DNA of minute virus of mice, a parvovirus

The formation of double-stranded viral DNA was examined in synchronized cells infected with minute virus of mice in early G1 phase. In the infected cells, a minimum of 50-100 copies of the input single-stranded DNA have been converted to a double-stranded form by mid S phase. In well-synchronized cells, the amount of double-stranded form by mid A phase. In well-synchronized cells, the amount of double-stranded viral DNA detected during G1 is on the order of a few copies per cell or less. When cells are infected in the presence of the thymidine analog, 5-bromodeoxyuridine, viral DNA synthesis is inhibited. However, 5-bromodeoxyuridine does not inhibit host DNA synthesis nor does it prevent replication of viral DNA if added to the infected cells in late S phase. Viral DNA replication first becomes resistant to 5-bromodeoxyuridine inhibition at the beginning of S phase. As 5-bromodeoxyuridine appears to specifically block early steps in viral DNA synthesis but not the subsequent replication of the DNA, the conversion of the input viral genome to a double-stranded form which undergoes further replication appears to be a S phase-specific event.