Abrupt rise of the longitudinal recoil ion momentum distribution for ionizing collisions

We report on the experimental observation of an abrupt rise in the longitudinal momentum distribution of recoil ions created in proton helium collision. The details of this structure can be related to electrons traveling with the velocity of the projectile [electron capture to the continuum (ECC)]. The longitudinal as well as the transverse distribution of the recoil ions can be explained as a continuation of the momentum distribution from ions resulting from electron capture illustrating the smooth transition from the capture to bound states of the projectile to the ECC.

Selective cancer cell killing by alpha-tocopheryl succinate

We report that alpha-tocopheryl succinate, a vitamin E analogue with pro-apoptotic properties, selectively kills cells with a malignant or transformed phenotype, i.e. multiple haematopoietic and carcinoma cell lines, while being non-toxic to normal, i.e. primary and non-transformed cells. These findings strongly suggest a potential of this micronutrient in the therapy and/or prevention of cancer without significant side-effects.

NMR structure of the N-SH2 of the p85 subunit of phosphoinositide 3-kinase complexed to a doubly phosphorylated peptide reveals a second phosphotyrosine binding site

The N-terminal src homology 2 (SH2) domain of the p85 subunit of phosphoinositide 3-kinase (PI3K) has a higher affinity for a peptide with two phosphotyrosines than for the same peptide with only one. This unexpected result was not observed for the C-terminal SH2 from the same protein. NMR structural analysis has been used to understand the behavior of the N-SH2. The structure of the free SH2 domain has been compared to that of the SH2 complexed with a doubly phosphorylated peptide derived from polyomavirus middle T antigen (MT). The structure of the free SH2 domain shows some differences from previous NMR and X-ray structures. In the N-SH2 complexed with a doubly phosphorylated peptide, a second site for phosphotyrosine interaction has been identified. Further, line shapes of NMR signals showed that the SH2 protein-ligand complex is subject to temperature-dependent conformational mobility. Conformational mobility is also supported by the spectra of the ligand peptide. A binding model which accounts for these results is developed.

Long-term pharmacokinetics of transdermal testosterone gel in hypogonadal men

Transdermal delivery of testosterone (T) represents an effective alternative to injectable androgens. Transdermal T patches normalize serum T levels and reverse the symptoms of androgen deficiency in hypogonadal men. However, the acceptance of the closed system T patches has been limited by skin irritation and/or lack of adherence. T gels have been proposed as delivery modes that minimize these problems. In this study we examined the pharmacokinetic profiles after 1, 30, 90, and 180 days of daily application of 2 doses of T gel (50 and 100 mg T in 5 and 10 g gel, delivering 5 and 10 mg T/day, respectively) and a permeation-enhanced T patch (2 patches delivering 5 mg T/day) in 227 hypogonadal men. This new 1% hydroalcoholic T gel formulation when applied to the upper arms, shoulders, and abdomen dried within a few minutes, and about 9-14% of the T applied was bioavailable. After 90 days of T gel treatment, the dose was titrated up (50 mg to 75 mg) or down (100 mg to 75 mg) if the preapplication serum T levels were outside the normal adult male range. Serum T rose rapidly into the normal adult male range on day 1 with the first T gel or patch application. Our previous study showed that steady state T levels were achieved 48-72 h after first application of the gel. The pharmacokinetic parameters for serum total and free T were very similar on days 30, 90, and 180 in all treatment groups. After repeated daily application of the T formulations for 180 days, the average serum T level over the 24-h sampling period (C(avg)) was highest in the 100 mg T gel group (1.4- and 1.9-fold higher than the C(avg) in the 50 mg T gel and T patch groups, respectively). Mean serum steady state T levels remained stable over the 180 days of T gel application. Upward dose adjustment from T gel 50 to 75 mg/day did not significantly increase the C(avg), whereas downward dose adjustment from 100 to 75 mg/day reduced serum T levels to the normal range for most patients. Serum free T levels paralleled those of serum total T, and the percent free T was not changed with transdermal T preparations. The serum dihydrotestosterone C(avg) rose 1.3-fold above baseline after T patch application, but was more significantly increased by 3.6- and 4.6-fold with T gel 50 and 100 mg/day, respectively, resulting in a small, but significant, increase in the serum dihydrotestosterone/T ratios in the two T gel groups. Serum estradiol rose, and serum LH and FSH levels were suppressed proportionately with serum T in all study groups; serum sex hormone-binding globulin showed small decreases that were significant only in the 100 mg T gel group. We conclude that transdermal T gel application can efficiently and rapidly increase serum T and free T levels in hypogonadal men to within the normal range. Transdermal T gel provided flexibility in dosing with little skin irritation and a low discontinuation rate.

Percutaneous absorption of sunscreens in vitro: interspecies comparison, skin models and reproducibility aspects

Appropriate evaluation of sunscreens is required to provide better knowledge of their safety and efficacy. One of the most important elements of this evaluation is the assessment of percutaneous absorption. In vitro methods are largely used for such assessments, and the accuracy of the measurements generated with these methods depends on the use of a proper methodology. This study was designed to evaluate an in vitro protocol for investigating the percutaneous absorption of two sunscreens under standardized experimental conditions. Octyl methoxycinnamate and benzophenone 4 were each incorporated in a typical oil-in-water emulsion and tested separately. Salicylic acid was tested as a reference compound. In vitro percutaneous absorption was evaluated using two species, the pig and human, and two models, full-thickness and split-thickness skin. The reproducibility of study results was evaluated by comparing the data generated by two industrial laboratories, L'Oréal and Hoffmann-La Roche. The correlation of quantitative data between pig skin and human skin was very good, and the split-thickness skin model seemed to be more appropriate for measuring the absorption of sunscreens. Results obtained for salicylic acid demonstrated the relevance of the protocol in terms of prediction of in vivo percutaneous absorption. Finally, the comparison of pig skin data between the two laboratories demonstrated a good correlation and underlined the need for a standardized in vitro procedure.

Analysis of the transcriptional control region in progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease caused by the human polyomavirus JCV. The hypervariable noncoding transcriptional control region (TCR) largely regulates replication of JCV in glial cells. Two distinct types of the TCR can be distinguished. Type II is derived from the archetype sequence. All type I TCRs, including the prototypical Mad-1 isolate contain a 23 bp deletion at nucleotide position 36. In a prospective study, TCR-DNA could be amplified and sequenced in 16/29 (55%) suspect cases of PML from the cerebrospinal fluid (CSF) and in 14/28 (50%) urine samples. Sequencing of the CSF-TCR identified Mad-1 like sequences in 5/17 (29.5%) instances and a type II TCR in 12/17 (70.5%) of cases. Of 14 urine TCRs, 12 (86%) displayed the archetype sequence, while two showed complex rearrangements. In all type II TCR sequences, the tst-1/oct-6 binding sites present in regions C and E of Mad-1 were missing. In 11/12 type II TCR sequences the pentanucleotide repeat in region A showed a G to T substitution of one nucleotide at position 36 relative to the Mad-1 TCR. All type II TCRs contained an Sp1 binding site at the beginning of region B. Of the 12 TCR type II sequences, 10 (83%) were of the 'D-retaining' pattern. In eight of these (80%) additional juxtapositioned nuclear factor 1, glial factor 1 and/or AP-1 binding motifs were created by duplications and/or insertions in region D. These findings indicate that type II TCRs are frequently present in PML and suggest to use TCR type II constructs for in vitro and in vivo studies of the evaluation of the functional role of DNA binding motifs.

Who is using cannabis as a medicine and why: an exploratory study

This article reports on an exploratory study of medical cannabis users. Interviews were completed with 50 self-identified medical cannabis users recruited through notices in newspapers and on bulletin boards. They reported using cannabis for a variety of conditions including HIV-AIDS-related problems, chronic pain, depression, anxiety, menstrual cramps, migraine, narcotic addiction as well as everyday aches, pains, stresses and sleeping difficulties. A majority also used cannabis for recreational purposes, and many were longer-term cannabis users. However, there were some notable exceptions. Almost all smoked cannabis and many did so two to three times a day. Few admitted negative experiences with cannabis, although some problems evident to the researchers were not clearly admitted. Those who told their doctors about their medical cannabis use found doctors noncommittal or supportive. The results raise questions about the definition of medical cannabis use and about policies that might be developed to accommodate such use. Limitations of the study are noted and further research suggested. Research priorities include population surveys, studies involving larger, more representative samples of medical cannabis users and studies of medical cannabis use among people with HIV-AIDS.

Tromethamine buffer modifies the depressant effect of permissive hypercapnia on myocardial contractility in patients with acute respiratory distress syndrome

In patients with acute respiratory distress syndrome (ARDS), permissive hypercapnia is a strategy to decrease airway pressures to prevent ventilator-induced lung damage by lowering tidal volumes and tolerating higher arterial carbon dioxide tension. However, in experimental studies hypercapnia impairs myocardial contractility and hemodynamic function. We investigated the effect of short-term permissive hypercapnia on myocardial contractility and hemodynamics in patients with ARDS. We hypothesized that the administration of tromethamine (THAM), a buffer which does not increase carbon dioxide production, would modify these changes. In 12 patients with ARDS, permissive hypercapnia was implemented for 2 h with a target Pa(CO(2))of 80 mm Hg. Patients were randomized to have respiratory acidosis corrected by THAM (pH-corrected group), or not corrected (pH-uncorrected group). Hemodynamic responses were measured, and transesophageal echocardiography (TEE) was used to determine myocardial contractility. Permissive hypercapnia resulted in significant decreases in systemic vascular resistance (SVR) and increases in cardiac output (Q). Myocardial contractility decreased in both groups but significantly less in the pH-corrected group (approximately 10%) than in the pH-uncorrected group (approximately 18%, p < 0.05). Mean arterial pressure decreased and mean pulmonary arterial pressure increased significantly only in the pH-uncorrected group. All values returned to baseline conditions 1 h after permissive hypercapnia was terminated. Our study demonstrates a reversible depression of myocardial contractility and hemodynamic alterations during rapid permissive hypercapnia which were attenuated by buffering with THAM. This may have applicability to the clinical strategy of permissive hypercapnia and allow the benefit of decreased airway pressures to be realized while minimizing the adverse hemodynamic effects of hypercapnic acidosis.

[Coronary angiography in patients over 80 years of age: indications, results, consequences]

Due to the continuous increase of elderly individuals in the society the cardiologist has to deal with elderly patients more often. The apparative expenditures and the invasive procedure require a critical consideration of benefits and risks prior to performing coronary angiography in these patients. The indication and frequency of coronary angiography in patients with eighty years or above were investigated. Furthermore, the results of angiography, the risks of the procedure and the therapeutic consequences were evaluated. The whole study population consisted of 2,500 consecutive patients (1,557 men, 943 women), who underwent coronary angiography at our institution from January 1st to November 16th in 1998. A retrospective analysis of 66 coronary angiographies (3%) in 61 patients (26 men, 35 women) aged 80 years or older was performed. Among these 61 patients, 51 were referred because of suspected coronary artery disease. Due to the clinical presentation a high percentage (42 patients = 82%) was classified as having unstable angina. 10 patients were referred due to valvular heart disease. Single-vessel disease was found in 14, two-vessel disease in 5 and multi-vessel disease in 28 patients, respectively. Percutaneous coronary intervention was performed in 17 patients, among these were 9 patients with multi-vessel disease and PTCA of the culprit lesion, and 3 patients underwent bypass surgery. Medical therapy was decided as to 28 patients. Aortic valve replacement was performed in 2 of 9 patients with aortic stenosis. The clinical appearance of coronary artery disease in elderly patients was mostly unstable angina, explaining the need for intervention. Coronary angiography disclosed multi-vessel disease in 55% of patients. A revascularization procedure could be performed at least in 43% of patients with multi-vessel disease.

Functional architecture of an intracellular membrane t-SNARE

Lipid bilayer fusion is mediated by SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) located on the vesicle membrane (v-SNAREs) and the target membrane (t-SNAREs). The assembled v-SNARE/t-SNARE complex consists of a bundle of four helices, of which one is supplied by the v-SNARE and the other three by the t-SNARE. For t-SNAREs on the plasma membrane, the protein syntaxin supplies one helix and a SNAP-25 protein contributes the other two. Although there are numerous homologues of syntaxin on intracellular membranes, there are only two SNAP-25-related proteins in yeast, Sec9 and Spo20, both of which are localized to the plasma membrane and function in secretion and sporulation, respectively. What replaces SNAP-25 in t-SNAREs of intracellular membranes? Here we show that an intracellular t-SNARE is built from a 'heavy chain' homologous to syntaxin and two separate non-syntaxin 'light chains'. SNAP-25 may thus be the exception rather than the rule, having been derived from genes that encoded separate light chains that fused during evolution to produce a single gene encoding one protein with two helices.

Molecular characterization of the transition state regulator AbrB from Bacillus stearothermophilus

The Bacillus subtilis transition state regulator AbrB(su) is a DNA-binding protein that acts on several genes either as activator, repressor, or preventer. However, among genes under its control, neither common binding sites could be identified nor could the structural features of this broad and specific interaction be elucidated. Attempts to elucidate these interesting features by crystallizing AbrB(su) have failed so far. Therefore, to solve this problem, we focused in this work on identifying an AbrB(su) homologue from Bacillus stearothermophilus. Using a novel method, the entire abrB(st) gene of B. stearothermophilus was cloned and sequenced. The gene encodes a 95 amino acid protein that shows 77% identity and 85% similarity to the mesophilic B. subtilis protein. A calmodulin binding peptide-tagged fusion of the thermophilic gene was constructed for overexpression and efficient affinity column purification of the AbrB(st) protein. The purified protein showed, after removal of the tag, an oligomerization behavior through hexamer formation that is essential for its DNA binding activity.

Prevalence of Chlamydia pneumoniae and Mycoplasma pneumoniae immunoglobulin G and A antibodies in a healthy Finnish population as analyzed by quantitative enzyme immunoassays

Chlamydia pneumoniae and Mycoplasma pneumoniae immunoglobulin G (IgG) and IgA antibody seroprevalence rates and antibody levels related to age and gender were studied. The samples (n = 742) were collected during a nonepidemic period and analyzed by quantitative enzyme immunoassays (EIAs). Seroprevalence to C. pneumoniae was found to increase sharply in young children, and in the 15- to 19-year-old group it reached levels as high as 70 and 60% for IgG and IgA, respectively. After adolescence, seroprevalence showed a transient decrease and then continued to increase, although less dramatically than in early childhood. In the elderly the seroprevalence of IgG antibodies reached 75 and 100% in women and men, respectively. The corresponding rates of IgA antibodies were 73 and 100%. When a randomly selected subgroup of samples (n = 66) was analyzed in parallel by a microimmunofluorescence test and an EIA for C. pneumoniae IgA antibodies, similar seroprevalence rates were obtained (36 versus 35%). Seroprevalence to M. pneumoniae was already found to increase very sharply in 2- to 4-year-old children, reaching 16% for IgG and 8% for IgA. Seroprevalence to M. pneumoniae also continued to increase in adolescence, but in contrast to that to C. pneumoniae, the increase leveled off at about 40 to 50% in adulthood. In subjects aged over 65 years, prevalence did not exceed 60% for IgG or 35% for IgA. The seroprevalence patterns as well as the medians and variations of levels of C. pneumoniae and M. pneumoniae IgG antibodies were similar to those of corresponding IgA antibodies. Compared to IgG antibodies, IgA antibodies do not seem to be of additional value in the diagnosis of infections caused by these pathogens when single serum specimens are studied.

Transdermal testosterone gel improves sexual function, mood, muscle strength, and body composition parameters in hypogonadal men

Testosterone (T) therapy for hypogonadal men should correct the clinical abnormalities of T deficiency, including improvement of sexual function, increase in muscle mass and strength, and decrease in fat mass, with minimal adverse effects. We have shown that administration of a new transdermal T gel formulation to hypogonadal men provided dose proportional increases in serum T levels to the normal adult male range. We now report the effects of 180 days of treatment with this 1% T gel preparation (50 or 100 mg/day, contained in 5 or 10 g gel, respectively) compared to those of a permeation-enhanced T patch (5 mg/day) on defined efficacy parameters in 227 hypogonadal men. In the T gel groups, the T dose was adjusted up or down to 75 mg/day (contained in 7.5 g gel) on day 90 if serum T concentrations were below or above the normal male range. No dose adjustment was made with the T patch group. Sexual function and mood changes were monitored by questionnaire, body composition was determined by dual energy x-ray absorptiometry, and muscle strength was measured by the one repetitive maximum technique on bench and leg press exercises. Sexual function and mood improved maximally on day 30 of treatment, without differences across groups, and showed no further improvement with continuation of treatment. Mean muscle strength in the leg press exercise increased by 11 to 13 kg in all treatment groups by 90 days and did not improve further at 180 days of treatment. Moderate increases were also observed in arm/chest muscle strength. At 90 days of treatment, lean body mass increased more in the 100 mg/day T gel group (2.74 +/- 0.28 kg; P = 0.0002) than in the 50 mg/day T gel (1.28 +/- 0.32 kg) and T patch groups (1.20 +/- 0.26 kg). Fat mass and percent fat were not significantly decreased in the T patch group, but showed decreases in the T gel groups (50 mg/day, -0.90 +/- 0.32 kg; 100 mg/day, - 1.05 +/- 0.22 kg). The increase in lean mass and the decrease in fat mass were correlated with the changes in average serum T levels attained after transdermal T replacement. These beneficial effects of T replacement were accompanied by the anticipated increases in hematocrit and hemoglobin but without significant changes in the lipid profile. The increase in mean serum prostate-specific antigen levels (within the normal range) was correlated with serum levels of T. The greatest increases were noted in the 100 mg/day T gel group. Skin irritation was reported in 5.5% of subjects treated with T gel and in 66% of subjects in the permeation-enhanced T patch group. We conclude that T gel replacement improved sexual function and mood, increased lean mass and muscle strength (principally in the legs), and decreased fat mass in hypogonadal men with less skin irritation and discontinuation compared with the recommended dose of the permeation-enhanced T patch.

Close is not enough: SNARE-dependent membrane fusion requires an active mechanism that transduces force to membrane anchors

Is membrane fusion an essentially passive or an active process? It could be that fusion proteins simply need to pin two bilayers together long enough, and the bilayers could do the rest spontaneously. Or, it could be that the fusion proteins play an active role after pinning two bilayers, exerting force in the bilayer in one or another way to direct the fusion process. To distinguish these alternatives, we replaced one or both of the peptidic membrane anchors of exocytic vesicle (v)- and target membrane (t)-SNAREs (soluble N-ethylmaleimide-sensitive fusion protein [NSF] attachment protein [SNAP] receptor) with covalently attached lipids. Replacing either anchor with a phospholipid prevented fusion of liposomes by the isolated SNAREs, but still allowed assembly of trans-SNARE complexes docking vesicles. This result implies an active mechanism; if fusion occurred passively, simply holding the bilayers together long enough would have been sufficient. Studies using polyisoprenoid anchors ranging from 15-55 carbons and multiple phospholipid-containing anchors reveal distinct requirements for anchors of v- and t-SNAREs to function: v-SNAREs require anchors capable of spanning both leaflets, whereas t-SNAREs do not, so long as the anchor is sufficiently hydrophobic. These data, together with previous results showing fusion is inhibited as the length of the linker connecting the helical bundle-containing rod of the SNARE complex to the anchors is increased (McNew, J.A., T. Weber, D.M. Engelman, T.H. Sollner, and J.E. Rothman, 1999. Mol. Cell. 4:415-421), suggests a model in which one activity of the SNARE complex promoting fusion is to exert force on the anchors by pulling on the linkers. This motion would lead to the simultaneous inward movement of lipids from both bilayers, and in the case of the v-SNARE, from both leaflets.

[Clinical characteristics of patients with tardive dyskinesias]

Although there is a great number of studies on the relationship between tardive dyskinesia and patient characteristics, too often their validity is impaired by the lack of operationalized criteria for the description of patients and signs. Reliable phenotyping is of utmost importance for linking clinical data with data from methods in neurobiology or molecular genetics. 241 patients with the DSM IV diagnosis "schizophrenia" or "schizoaffective disorder" were examined with the instruments SADS-L, OPCRIT, BPRS and PANSS. Motor phenomena were analyzed on 2 separate days within 3 months with the scales TDRS, AIMS, SAS, BAS. Tardive dyskinesia was diagnosed following the research criteria of Schooler and Kane. Lifetime medication with neuroleptics and anticholinergic drugs was assessed quantitatively.

RESULTS

97 out of 233 patients (= 41.6%) displayed persistent tardive dyskinesia. In univariate analysis, significant associations were found between tardive dyskinesia and the following independent variables (higher values means greater risk): Age (p = 0.0001), years from onset of the disorder (p = 0.001), total length of stay in hospital (p = 0.001), PANSS (single scales and sum score) (p = 0.0001), total amount of neuroleptics expressed as CPZ equivalents (p = 0.004). Logistic regression analysis showed that only the variables "age" and "negative symptoms" expressed as score on the PANSS negative subscale showed an association with tardive dyskinesia that could not be explained by covariation with other variables. The same results were found when, instead of the dichotomous variable "tardive dyskinesia yes/no" the associations with the TDRS score were analyzed. Future research should aim to approach the neurobiological correlates of "age" and "negative symptoms" in relationship to tardive dyskinesia.

Transcriptional and mutational analyses of the Streptomyces lividans recX gene and its interference with RecA activity

The role of the 20,922-Da RecX protein and its interference with RecA activity were analyzed in Streptomyces lividans. The recX gene is located 220 bp downstream of recA. Transcriptional analysis by reverse transcriptase PCR demonstrated that recX and recA constitute an operon. While recA was transcribed at a basal level even under noninducing conditions, a recA-recX cotranscript was only detectable after induction of recA following DNA damage. The recA-recX cotranscript was less abundant than the recA transcript alone. The recX gene was inactivated by gene replacement. The resulting mutant had a clearly diminished colony size, but was not impaired in recombination activity, genetic instability, and resistance against UV irradiation. Expression of an extra copy of the S. lividans recA gene under control of the thiostrepton-inducible tipA promoter was lethal to the recX mutant, demonstrating that RecX is required to overcome the toxic effects of recA overexpression. Since inactivation of the recX gene did not influence transcription of recA, the putative function of the RecX protein might be the downregulation of RecA activity by interaction with the RecA protein or filament.

Cerebrospinal fluid analysis for the diagnosis of human immunodeficiency virus-related neurologic diseases

Although early attempts demonstrated increased amounts of p24 antigen in the cerebrospinal fluid (CSF) of AIDS patients with dementia (HADC), gene amplification based assays have recently shown a correlation between the HI virus load in CSF and dementia. Although these correlations are valid for a large population, current evidence does not favor the use of CSF HI virus load measurement for the diagnosis of HADC. By polymerase chain reaction, opportunistic infections of the central (CNS) and peripheral nervous system due to cytomegalovirus, JC virus, and herpes simplex virus types 1 and 2 and primary lymphoma caused by Epstein-Barr virus can be diagnosed with an overall sensitivity ranging from 76% to 98% and a specificity between 98% and 99.5%. In contrast, bacterial, protozal, and fungal infections of the CNS are still better diagnosed by conventional assays such as culture, antigen detection, and empirical therapy. Brain biopsy still remains the ultimate means of obtaining a specific diagnosis in selected cases.

Solution structure of PCP, a prototype for the peptidyl carrier domains of modular peptide synthetases

BACKGROUND

Nonribosomal peptide synthetases (NRPSs) are large modular enzymes responsible for the synthesis of a variety of microbial bioactive peptides. They consist of modules that each recognise and incorporate one specific amino acid into the peptide product. A module comprises several domains, which carry out the individual reaction steps. After activation by the adenylation domain, the amino acid substrate is covalently tethered to a 4'-phosphopantetheinyl cofactor of a peptidyl carrier domain (PCP) that passes the substrate to the reaction centres of the consecutive domains.

RESULTS

The solution structure of PCP, a distinct peptidyl carrier protein derived from the equivalent domain of an NRPS, was solved using NMR techniques. PCP is a distorted four-helix bundle with an extended loop between the first two helices. Its overall fold resembles the topology of acyl carrier proteins (ACPs) from Escherichia coli fatty acid synthase and actinorhodin polyketide synthase from Streptomyces coelicolor; however, the surface polarity and the length and relative alignment of the helices are different. The conserved serine, which is the cofactor-binding site, has the same location as in the ACPs and is situated within a stretch of seven flexible residues.

CONCLUSIONS

The structure of PCP reflects its character as a protein domain. The fold is well defined between residues 8 and 82 and the structural core of the PCP domain can now be defined as a region spanning 37 amino acids in both directions from the conserved serine. The flexibility of the post-translationally modified site might have implications for interactions with the cooperating proteins or NRPS domains.

Functional characteristics of the telemedical network for the medical service of the Bundeswehr for support of operations outside Germany and civil-military co-operation

The maxim governing the accomplishment of medical tasks by the Medical Service of the Bundeswehr stipulates that the soldiers will, in case of illness, accident or injury, receive medical treatment to the standard they can expect in the Federal Republic of Germany. In this context the introduction of telemedical applications into the Medical Service will improve the quality of the medical care through better and faster access for the medical officer assigned to a unit or a ship for requesting support to expert knowledge from military facilities or the civilian sector. The telemedical system is based on a high-class commercial PC. This workstation can be extended as needed with medical devices (x-ray film digitizer, dermatoscope, otoscope) and allows linkage to other imaging methods (e.g., videocamera, ultrasound). Currently this system is under evaluation in a multi centre trial. The participants of this telemedical network communicate via EURO ISDN lines with sufficient bandwidth. If terrestrial lines are not available the communication will be based on satellite capacity. The application of internet-technology additionally provides access to medical data bases respectively allows civil-military co-operation and the interoperability between medical services of allied armed forces. This future-orientated telemedical approach with its modular upwards-compatibility will provide, especially in its mobile version and by using communication standards, the possibility to support necessary civil-military co-operation in the area of disaster relief and missions outside of Germany in the future.

The early response genes c-jun and HSP-70 are induced in regional cardiac stunning in conscious mammals

OBJECTIVES

A reversible contractile dysfunction without necrosis after transient myocardial ischemia has been termed stunning. The molecular mechanisms underlying this phenomenon are only now beginning to be unraveled. It is conceivable that the expression of early-response genes may play a crucial role in stunning.

METHODS

The expression of HSP-70, c-jun, and GRP-94 was investigated in a chronically instrumented dog model (n = 9). The left anterior descending coronary artery was occluded temporarily for 10 minutes after the animals had fully recovered from instrumentation. The wall thickening fraction was measured in the left anterior descending coronary artery and the nonischemic ramus circumflex of the left coronary artery-perfused region. When the wall thickening fraction of the left anterior descending coronary artery had recovered to 50% of preocclusion values, tissue samples were obtained from the areas perfused by the left anterior descending coronary artery and the nonischemic ramus circumflex of the left coronary artery.

RESULTS

The messenger RNA of HSP-70 was increased to 214% +/- 26% in the area perfused by the left anterior descending artery compared with that perfused by the nonischemic ramus circumflex of the left coronary artery. There was no difference in the messenger RNA of GRP-94. The HSP-70 content was elevated to 130% +/- 14% in the left anterior descending artery compared with the area perfused by the ramus circumflex of the left coronary artery, and the c-jun protein content was 70% +/- 25% higher in the ischemic area compared with the control area.

CONCLUSIONS

The induction of early-response genes observed here may indicate that they play an adaptive role in myocardial stunning, even in conscious mammals.

Putative fusogenic activity of NSF is restricted to a lipid mixture whose coalescence is also triggered by other factors

It has recently been reported that N-ethylmaleimide-sensitive fusion ATPase (NSF) can fuse protein-free liposomes containing substantial amounts of 1,2-dioleoylphosphatidylserine (DOPS) and 1, 2-dioleoyl-phosphatidyl-ethanolamine (DOPE) (Otter-Nilsson et al., 1999). The authors impart physiological significance to this observation and propose to re-conceptualize the general role of NSF in fusion processes. We can confirm that isolated NSF can fuse liposomes of the specified composition. However, this activity of NSF is resistant to inactivation by N-ethylmaleimide and does not depend on the presence of alpha-SNAP (soluble NSF-attachment protein). Moreover, under the same conditions, either alpha-SNAP, other proteins apparently unrelated to vesicular transport (glyceraldehyde-3-phosphate dehydrogenase or lactic dehydrogenase) or even 3 mM magnesium ions can also cause lipid mixing. In contrast, neither NSF nor the other proteins nor magnesium had any significant fusogenic activity with liposomes composed of a biologically occurring mixture of lipids. A straightforward explanation is that the lipid composition chosen as optimal for NSF favors non-specific fusion because it is physically unstable when formed into liposomes. A variety of minor perturbations could then trigger coalescence.