Attachment of human uveal melanocytes and melanoma cells to extracellular matrix proteins involves intracellular calcium and calmodulin

The purpose of this study was to examine which intracellular signalling systems influence the attachment of normal uveal melanocytes and uveal melanoma cells to extracellular matrix (ECM) proteins in vitro. Uveal melanocytes were found to attach strongly to fibronectin in preference to plastic, collagens type I, III or IV, or laminin. In contrast, uveal melanoma cells attached equally well to fibronectin and collagens I, III and IV in preference to plastic or laminin. Manipulation of intracellular cyclic AMP or protein kinase C had little, if any, effect on the attachment of either cell to fibronectin. In contrast, inhibition of calmodulin significantly inhibited the attachment of both normal and transformed cells, as did manipulating intracellular free calcium. We noted that the intracellular free calcium in melanoma cells was less than half that seen in melanocytes. Fibronectin, laminin and Arg-Gly-Asp (RGD) were all capable of acutely increasing the intracellular free calcium in both cells. ECM-induced increases in calcium were more apparent in low density than high density cells and appeared more sustained in melanocytes than in melanoma cells. We conclude that both normal and neoplastic uveal melanocytes require an intracellular signal or signals which involves calcium and calmodulin in the few minutes following cell binding to ECM proteins in order for successful cell attachment to occur. While the transformed cell does not differ significantly from the normal cell in this respect, this dependency on calcium and calmodulin may nevertheless offer an approach for pharmacological intervention in the prevention or arrest of metastatic spread and merits further investigation.

Human herpesvirus-6 (HHV-6)-associated necrotizing encephalitis in Griscelli's syndrome

We report a male caucasian German pediatric patient of no Arab or Mediterranean ancestry with virus associated CNS lesions in Griscelli's syndrome (GS; McKusick No. 214450). The boy presented with recurrent infections, and meningitis with subsequent progressive signs of increased intracranial pressure leading to death at 32 weeks of age. At autopsy, various sites of the CNS revealed necroses in gray and white matter. CNS histology revealed numerous and massive predominantly perivascular CD8 positive lymphohistiocytic infiltrates. These findings were associated strictly with the presence of human herpesvirus-6 (HHV-6) genome or the HHV-6 specific late antigen H-AR 3, found in neurons, oligodendrocytes, and astrocytes. The search for HHV-6 replication dependent antigen, HHV-7 DNA, CMV, adenovirus, Coxsackie B1, B2, and B4-antigens, and mycobacteria was not successful. Detection of viruses was attempted using immunohistochemistry, in situ hybridization or nested polymerase chain reaction, respectively. Lymphocyte typing was carried out immunohistochemically. In GS, virus induced CNS damage does not seem to require necessarily active virus replication. It may also appear as a consequence of an immune reaction triggered by antigen expression.

Physiology and cell biology of the endothelium: a dynamic interface for cell communication

This manuscript presents a brief overview of the physiology and cell biology of the endothelium, which is the basis for understanding the role of endothelial cells in pathological processes as diverse as atherosclerosis, tumour intravasation and multiple organ failure. Following consideration of general aspects of endothelial function in regulating haemostasis, vascular tone and growth, special emphasis will be placed on endothelial regulation of the inflammatory response, which centres on the microcirculation. A particular role in inflammation is played by cell adhesion molecules (CAM), expressed both on endothelial and blood cells. Cell and molecular biological methods to investigate the expression of CAM in endothelial cells in vitro will be presented, as well as novel data, indicating that cytokine-induced up-regulation of CAM in the endothelium may involve signal transduction pathways other than those culminating in the activation of NF-kappa B. Finally, the phenomenon of angiogenesis will be briefly reviewed as a characteristic of endothelial cell activity of central importance to both physiology and pathology and new experimental data presented from an in vitro model to study the ability of individual endothelial cells to form vessel-like structures. In comparative studies to investigate the roles of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor, the dominant role of VEGF in the formation of capillary networks could be unequivocally demonstrated.

[MNGIE syndrome in 2 siblings]

Two siblings (one man, one woman), presenting with diarrhea, severe weight loss peripheral neuropathy, ophthalmoparesis, asymptomatic leukoencephalopathy were diagnosed as a new cases of Mitochondrial Neuro Gastro Intestinal Encephalomyopathy syndrome (MNGIE). Hirano (1994) defined four criteria for the diagnostic: peripheral neuropathy, ophthalmoparesis, gastro intestinal dysmotility, muscle biopsy with histologic features of mitochondrial myopathy (ragged-red fibers, muscle fibers with increased succinate deshydrogenase stain or ultra structurally abnormal mitochondria). In a review of the literature, we found 31 cases with MNGIE. With our two cases, we study this group of 33 patients. First symptoms begin about 13.5 years with a median of 10 years and extremes for 1 to 32 years. The first signs are gastro intestinal symptoms (recurrent nausea, vomiting or diarrhea with intestinal dysmotility) in 22 cases, an ophthalmoparesia in 4 cases, intestinal and ocular signs in 1 case, gait ataxia or peripheral neuropathy in 3 cases, hearing loss in 1 case, gait ataxia or peripheral neuropathy in 3 cases, hearing loss in 1 case. During the evolution, besides the cardinal signs, the following features have been observed with a variable frequency: hearing loss, short stature, facial palsy, dysphonia, dysarthria, sweating, orthostatic hypotension, bladder dysfunction, hepatomegalia, The laboratory features are: abnormal Nerve Condition Studies/EMG compatible with a sensory motor neuropathy, lactic acidosis, mitochondrial respiratory chain defect (essentially complex IV deficiency, complex I deficiency or multiple complex defect), MRI leukodystrophy, elevated CSF protein, heart block, ragged-red fibers or increased SDH stain. The prognosis is poor, due to a severe weight loss bordering on cachexia 13 patients died with a mean age of 28.5 years (median 24 years, extreme 3 years to 51 years). The prognosis seems to be worsened by a young age of onset. The 33 patients belong to 19 families with 7 cases of consanguinity. 25 patients had a brother, a sister or a cousin affected. The study of these families is compatible with an autosomic recessive transmission, suggesting a pathology of the nuclear genomi, probably impliying the control of the mitochondrial DNA replication. In fact, in 13 cases, a study of the mt DNA was realized: multiple deletions were founded in 6 cases, multiples mutations in one case, unique mutation in 1 case. In 5 cases ther was no evidence of abnormality. These precise etiology and pathophysiologic significance of the mt DNA deletions, and the heterogeneity of the modifications of the mt DNA remain unknown. However, the possibility of various phenotypes for a same genotype or inversely is known in mitochondriopathies.

Pharmacokinetic/pharmacodynamic evaluation of systemic effects of flunisolide after inhalation

The pharmacokinetics and pharmacodynamics of flunisolide were studied in healthy volunteers after inhalation. In the morning on the day the study began, volunteers inhaled 0.5 mg of flunisolide with and without oral administration of charcoal, or 1 mg, 2 mg, and 3 mg of flunisolide with concomitant administration of charcoal. A placebo group was used to assess the endogenous cortisol, granulocyte, and lymphocyte baseline levels. Flunisolide plasma levels were determined by high-performance liquid chromatography using a tandem mass spectrometer as detector (HPLC/MS/MS). Cortisol plasma levels and differential white blood cell counts were obtained over 12 hours. An integrated pharmacokinetic/pharmacodynamic (PK/PD) model was applied to link the flunisolide plasma concentrations with the effects on lymphocytes, granulocytes, and cortisol. Maximum concentration levels of 3 to 9 ng/mL of flunisolide were observed after 0.2 to 0.3 hours for all of the investigated doses. The terminal half-life ranged from 1.3 to 1.7 hours. There was no statistical difference between treatments in the presence or absence of orally administered charcoal. The pharmacokinetic/pharmacodynamic (PK/PD) models satisfactorily described the time-courses of the effects on granulocytes, lymphocytes, and cortisol suppression. The resulting E50-values (concentrations to induce 50% of the maximum effect) concurred with the reported values of in vitro receptor binding affinities. The duration of the systemic effects were short because of the short half-life of the drug. Cumulative cortisol suppression increased with dose administration and ranged from 20% to 36%. The PK/PD simulations resulted in a smaller degree of cortisol suppression for the drug administered at 10 PM. The cumulative change from baseline was slightly smaller for the effects on granulocytes and lymphocytes than those on cortisol. This information promotes the comparison with other inhaled glucocorticoids.

[99mTc-MDP-SPECT for detection of subclinical mandibular infiltration of squamous epithelial carcinoma]

A prospective study was performed to compare the sensitivity and accuracy of ultrasound (US), computed tomography (CT), and single photon emission computed tomography (SPECT) as a bone scan to detect subclinical invasion of the mandible by squamous cell carcinoma of the oral cavity and floor of mouth.

METHODS

The present study reports data on 35 patients with squamous cell carcinoma of the oral cavity. SPECT, mandibular orthopantomography (OPG), US, CT and magnetic resonance imaging (MRI) were performed as well as histologic examination of resected mandibles. Transverse slices of 12 mm thickness were reconstructed for SPECT and semi-quantitative assessment of radionuclide uptake was performed with a scoring system based on comparisons of tracer uptake in the mandible to that in an unaffected part of the mandible. Lesion to non-lesion count ratios in the mandible in 3 h SPECT images were calculated. OPG, US and CT were evaluated for comparison.

RESULTS

In 12/35 patients, histologic examination showed carcinoma infiltrating mandibular bone. SPECT correctly predicted mandibular invasion in 11/12 cases, with no false-positive results. CT detected correctly 3/12 lesions, while OPG and ultrasound each demonstrated 2/12 tumors.

CONCLUSION

Bone SPECT was found to provide an accurate means for assessing tumor invasion to the mandible by intraoral squamous cell carcinoma. As a complementary study to one of the other imaging modalities it was shown to have a high specificity, indicating that it should be performed routinely in patients with suspect mandibular bone involvement by causes.

[Dementia in the very elderly. Results of the Berlin Aging Study]

The frequency of dementia in very old subjects, the risk factors and the consequences of the disease were investigated in the Berlin Aging Study in an age- and gender-stratified design (ages 70-103 years, n = 516). Psychiatrists diagnosed a dementia syndrome according to DSM-III-R, applying the GMS-A and HAS interviews. The dementia frequency steeply increases until the 90-94 year group, but there is no further exponential increase for the 95+ group--instead for men the data show a plateau of dementia prevalence. Low education level turned out to be a risk factor, which explains the gender effect in a logistic regression analysis. The apolipoprotein E4 genotype was confirmed as a risk factor--however, only for the older subjects (85+). Dementia was a major reason for institutionalization. The 2-year mortality was no higher in dementia than for age-matched non-demented controls. The results gave a detailed picture of dementia in the very old. This is a prerequisite for planning facilities for psychiatric diagnostics and therapy as well as nursing care.

Dependency of cortisol suppression on the administration time of inhaled corticosteroids

Endogenous cortisol suppression is one of the major systemic side effects of inhaled corticosteroids in the treatment of asthma. A previously developed pharmacokinetic/ pharmacodynamic approach was used to evaluate the influence of administration time on the cumulative cortisol suppression (CCS) after single doses of the inhaled corticosteroids flunisolide and fluticasone propionate. Administration time-dependent simulations of CCS were performed with drug-specific pharmacokinetic and pharmacodynamic parameters obtained from previous clinical trials. Both drugs showed similar diurnal variation in CCS, dependent on the administration time, with maximum suppression when administered in the early morning at approximately 3 AM. The optimum administration time for minimized CCS was in the afternoon but was shifted from 3 PM for fluticasone propionate to later time points around 7 PM for flunisolide, probably because of the shorter terminal elimination half-life of flunisolide. Regarding peak to trough fluctuation, however, CCS after fluticasone propionate showed only half the administration time dependency as after flunisolide. Therefore, the ratio between CCS after flunisolide and after fluticasone propionate also followed administration time-dependent variations. This led to the conclusion that administration time has to be considered as a pivotal influential factor in clinical studies comparing CCS among different inhaled corticosteroids.

Fast visual evoked potential input into human area V5

Studies of the human visual cortex have demonstrated that an area for motion processing (V5) is located in the lateral occipito-temporal cortex. To study the timing of arrival of signals in V5 we recorded multi-channel visual evoked potentials (VEPs) to checkerboard stimuli. We then applied dipole source analysis which was computed on a grand average of 10 subjects, and on five individual subjects, respectively. We demonstrate an early VEP component with onset before 30 ms and with a peak around 45 ms, located in the vicinity of V5. This early component was independent of a second activity, which started around 50 ms and peaked around 70 ms, and was located within the striate cortex (V1). These results provide further evidence for a very fast input to V5 before activation of V1.

New gadolinium complexes as magnetic resonance imaging--contrast agents

We have investigated the physicochemical and paramagnetic properties of the new gadolinium complexes of N-(pyrid-2-yl-methyl)-ethylenediamine-N,N,N-triacetic acid (Gd-PEDTA) and N-tris(2-aminoethyl)amine-N,N,N,N,N,N+hexaacetic acid(Gd-TTAHA). The relaxivities as well as the thermodynamic and conditional stability constants of these complexes with respect to the physiological relevance were determined and discussed in comparison with the commercially available gadolinium (III) diethylenetriaminpentaacetic acid/gadopentate dimeglumine (Gd-DTPA, Magnevist). In case of Gd-TTAHA a twofold higher relaxivity and a complex stability similar to Gd-DTPA were determined. It is shown, that lower concentrations of Gd-TTAHA are sufficient for the same signal enhancement in the T1-weighted MR image compared with Gd-DTPA and, thus, the use of the new contrast agent Gd-TTAHA should diminish risks for health. Therefore, Gd-TTAHA might be used potentially as a new contrast agent for clinical MRI application.

Investigation of oestrogen receptors, sex steroids and soluble adhesion molecules in the progression of malignant melanoma

The question of whether melanoma tumours have classical oestrogen receptors (ERs) is unresolved, but epidemiological data clearly show a survival benefit for female patients with metastatic melanoma. The aims of this study were to examine to what extent the presence of ER in melanoma tumours might relate to disease progression and whether disease progression relates to patients' sex steroid status. Additionally, levels of two soluble adhesion molecules [circulating intercellular adhesion molecule-1 (sICAM-1) and circulating vascular cell adhesion molecule-1 (sVCAM-1)] were examined as independent, possibly prognostic indicators of disease progression. ER immunocytochemical assay identified only two lesions (out of 69 investigated) which had any evidence of the receptors, and staining in these lesions was very modest. No significant changes in oestrone or androstenedione levels were noted for male or female patients with disease progression. As expected, oestradiol levels reflected the menopausal status of the female patients but, for all post-menopausal female patients and male patients, there was no significant relationship to tumour stage. However, a significant decrease in sex hormone-binding globulin occurred with disease progression in male but not female patients, and sex differences in the levels of soluble adhesion molecules were also seen in advanced metastatic disease.

Is OVX1 a suitable marker for endometrial cancer?

The single most common cause leading to the diagnosis of endometrial cancer is postmenopausal bleeding. Although most patients with early-stage disease (FIGO stage I and II) can be cured, prognosis worsens considerably with increasing stage. While serum CA 125 levels are elevated only in a significant proportion of patients with advanced disease, recently a new serum marker (OVX1) for the detection of early-stage endometrial cancer was reported. Serum OVX1 levels were measured using an OVX1 radioimmunoassay (RIA) or enzyme immunoassay (EIA) in 192 patients with endometrial cancer. CA 125 levels were measured in 112 patients using the CIS ELSA CA 125 kit. Apparently healthy females had mean serum OVX1 levels measured with the OVX1-EIA of 1.34 +/- 0.74 U/ml, while patients with endometriosis had mean OVX1 serum levels of 3.15 +/- 2.45 U/ml. The mean OVX1 serum level for endometrial cancer patients was 2.00 +/- 1.32 U/ml. These values were 2.76 +/- 1.62, 6.10 +/- 4.66, and 5.37 +/- 3.49, respectively, using the OVX1-RIA assay. Applying a cutoff value of 2.8 U/ml, serum OVX1-EIA levels in endometrial cancer patients were increased in 25 of 127 patients (19.7%) with stage I disease, 5 of 17 patients with stage II (29.4%), 5 of 22 patients (22.7%) with stage III, and 4 of 11 patients (36.4%) with stage IV disease. Using the OVX1-RIA and a cutoff of 7.2 U/ml, serum levels were increased in 22 of 127 (17.3%) stage I, 6 of 17 (35.3%) stage II, 5 of 22 (22.7%) stage III, and 6 of 11 (54.5%) stage IV patients. Serum CA 125 levels, determined in a total of 112 patients, were elevated above 35 U/ml in 12 of 79 patients (15.2%) with stage I, 4 of 12 patients (33.3%) with stage II, 8 of 13 patients (61.5%) with stage III, and all of 8 patients (100%) with stage IV disease. While a good correlation between serum CA 125 levels and the clinical stage of the disease was found, no correlation could be detected for OVX1 and stage.

Effect of FSH and insulin on lipogenesis in cultures of Sertoli cells from immature rats

Follicle-stimulating hormone (FSH) and insulin regulate glycide metabolism in Sertoli cells, thus stimulating lactate production. These stimulatory effects of FSH and insulin do not require protein synthesis, suggesting a modulation of enzyme activity and/or regulation of glucose transport. The present investigation was performed to characterize the hormonal control of lipid metabolism in Sertoli cells. The data indicate that FSH and insulin have a regulatory effect on lipid metabolism in Sertoli cells. After 8 h of preincubation with insulin (5 micrograms/ml), the activity of the enzyme ATP-citrate lyase in cultured Sertoli cells was increased from 0.19 to 0.34 nmol NAD+ formed microgram protein-1 min-1. FSH (100 ng/ml) had no effect on this enzyme. Glycerol phosphate dehydrogenase activity was not affected by any of the hormones tested. When Sertoli cells from 19-day old rats were incubated with [1,2-14C]acetate for 90 or 360 min, the [14C] label was present predominantly in triglyceride and phospholipid fractions with minor amounts in other lipids. In Sertoli cells pretreated for 16 h with insulin and FSH, an increase in acetate incorporation into lipids was observed. Most of the label was in esterified lipids and this percentage increased with the time of treatment; this increase was remarkable in triglycerides of control cells (18.8% to 30.6%). Since Sertoli cell triglycerides participate in the control of spermatogenesis, the present data suggest that the hormonal control of lipid metabolism in Sertoli cells is important not only for maintaining the energy of the cell itself, but also for the control of the spermatogenesis process.

Influence of freeze-concentration effect on proteinase-catalysed peptide synthesis in frozen aqueous systems

Freezing of the reaction mixture is a powerful tool in proteinase-catalysed peptide synthesis. In this study, the considerable yield-increasing effect of freezing has been analysed by physical and analytical methods. 1H-NMR relaxation time measurements have been used to determine the amount of unfrozen water in partially frozen systems thus quantifying the extent of the 'freeze concentration effect' for the first time. Comparative studies in ice and at room temperature verify the importance of freeze-concentration which, however, is not sufficient for a complete understanding of the observed effects. Furthermore, the phase behaviour of frozen systems is discussed.

Population structure of microbial communities associated with two deep, anaerobic, alkaline aquifers

Microbial communities of two deep (1,270 and 316 m) alkaline (pH 9.94 and 8.05), anaerobic (Eh, -137 and -27 mV) aquifers were characterized by rRNA-based analyses. Both aquifers, the Grande Ronde (GR) and Priest rapids (PR) formations, are located within the Columbia River Basalt Group in south-central Washington, and sulfidogenesis and methanogenesis characterize the GR and PR formations, respectively. RNA was extracted from microorganisms collected from groundwater by ultrafiltration through hollow-fiber membranes and hybridized to taxon-specific oligonucleotide probes. Of the three domains, Bacteria dominated both communities, making up to 92.0 and 64.4% of the total rRNA from the GR and PR formations, respectively. Eucarya comprised 5.7 and 14.4%, and Archaea comprised 1.8% and 2.5%, respectively. The gram-positive target group was found in both aquifers, 11.7% in GR and 7.6% in PR. Two probes were used to target sulfate- and/or metal-reducing bacteria within the delta subclass of Proteobacteria. The Desulfobacter groups was present (0.3%) only in the high-sulfate groundwater (GR). However, comparable hybridization to a probe selective for the desulfovibrios and some metal-reducing bacteria was found in both aquifers, 2.5 and 2.9% from the GR and PR formations, respectively. Selective PCR amplification and sequencing of the desulfovibrio/metal-reducing group revealed a predominance of desulfovibrios in both systems (17 of 20 clones), suggesting that their environmental distribution is not restricted by sulfate availability.

Inverse localization of electric dipole current sources in finite element models of the human head

The paper describes finite element related procedures for inverse localization of multiple sources in realistically shaped head models. Dipole sources are modeled by placing proper monopole sources on neighboring nodes. Lead field operators are established for dipole sources. Two different strategies for the solution of inverse problems, namely combinatorial optimization techniques and regularization methods are discussed and applied to visually evoked potentials, for which exemplary results are shown. Most of the procedures described are fully automatic and require only proper input preparation. The overall work for the example presented (from EEG recording to visual inspection of the results) can be performed in roughly a week, most of which is waiting time for the computation of the lead field matrix or inverse calculations on a standard and affordable engineering workstation.

The CDK-activating kinase CAK1 can dosage suppress sporulation defects of smk1 MAP kinase mutants and is required for spore wall morphogenesis in Saccharomyces cerevisiae

Mitogen-activated protein (MAP) kinase pathways are evolutionarily conserved kinase cascades that are required for the response of eukaryotic cells to a wide variety of environmental stimuli. MAP kinase pathways are also required for the execution of developmental and differentiative programs in a variety of cell and tissue types. SMK1 encodes a developmentally regulated MAP kinase in yeast that is required for spore wall morphogenesis. Cyclin-dependent kinase-activating kinases (CAKs) phosphorylate a conserved threonine residue in the activating loop of cyclin-dependent kinases. CAK1 encodes the major CAK activity in yeast and is required for cell cycle progression. The work presented here demonstrates that CAK1 functions positively in the spore wall morphogenesis pathway. First, CAK1 has been isolated as a dosage suppressor of a conditional smk1 mutant that is defective for spore wall morphogenesis. Second, CAK1 mRNA accumulates during spore development contemporaneously with SMK1 mRNA. Third, cak1 mutant strains have been isolated that are able to complete meiosis I and II but are specifically defective in assembly of the spore wall. These results show that cell cycle progression and morphogenetic pathways can be regulated by a single gene product and suggest mechanisms for coordinating these processes during development.