Momentum spectroscopy of 1D phase fluctuations in Bose-Einstein condensates

We measure the axial momentum distribution of Bose-Einstein condensates with an aspect ratio of 152 using Bragg spectroscopy. We observe the Lorentzian momentum distribution characteristic of one-dimensional phase fluctuations. The temperature dependence of the width of this distribution provides a quantitative test of quasicondensate theory. In addition, we observe a condensate length consistent with the suppression of density fluctuations, even when phase fluctuations are large.

Epidural corticosteroid injections for sciatica: a randomised, double blind, controlled clinical trial

OBJECTIVE

To determine the efficacy of epidural corticosteroid injections for sciatica.

METHODS

Three epidural injections (two day intervals) of 2 ml prednisolone acetate (50 mg) or 2 ml isotonic saline were administered to patients with sciatica presumably due to a disk herniation lasting 15-180 days. Self evaluation was the main judgment criterion at day 20. Patients who recovered or showed marked improvement were considered as success. Pain measured by VAS, the SLR test, Schober's test, Dallas pain questionnaire, and the Roland-Morris index were evaluated at days 0, 5, 20, and 35. Only analgesics were authorised, patients requiring non-steroidal anti-inflammatory drugs (NSAIDs) before day 20 were considered as failure.

RESULTS

42 patients were included in the control group (CG), 43 in the steroid group (SG). On an intention to treat analysis 15/42 (36%) in the CG and 22/43 (51%) in the SG (p=0.15) were considered as success (difference 15.5%, 95% CI (-5.4 to 36.3)). Among the 48 failures, 14 patients (6 CG, 8 SG) required NSAIDs, 3 (2 CG, 1 SG) required surgery, and 7 (3 CG, 4 SG) other treatments. On analysis according to protocol, in 74 remaining patients 12/35 (34%) in the CG and 22/39 (56%) in the SG (p=0.057) were considered as success (difference 22.1%, 95% CI (0.0 to 44.2)). For all secondary end points intragroup improvement with time was significant, but intergroup differences were not.

CONCLUSION

The efficacy of isotonic saline administered epidurally for sciatica cannot be excluded, but epidural steroid injections provide no additional improvement.

[Thrombus of the left lateral sinus spreading to the internal jugular vein]

Cerebral venous thrombosis is an uncommon event which presents a wide spectrum of sometimes extraneurological signs different from the classical clinical presentation. We report the cases of two middle-aged women who developed thrombosis of the left lateral sinus spread-ing to the internal jugular vein from the sigmoid sinus. The time course of the symptoms suggested that intracranial thrombosis occurred first. No infectious or neoplastic local disease could be found but both women were taking oral contraceptives. Medical treatment led to good reperfusion of the intracranial sinuses but occlusion of the jugular vein persisted despite prolonged oral anticoagulants. Long-term outcome was favorable with residual benign epilepsy in one patient, and occurrence of an arteriovenous fistula in the other.

New perspectives on the key role of calcium in the progression of heart disease

The heart continuously adapts to adjust its output to a continuum of pathophysiological situations ensuring adequate blood distribution. These situations range from high performance in well-trained athletes to failure in a variety of cardiac syndromes. Changes in the concentration of intracellular Ca2+ ([Ca2+]i) are crucial. They have immediate and late effects that can be oversimplified as follows. Immediate effects result from abrupt and large variations in [Ca2+]i triggering contraction after binding to the contractile proteins. These variations are involved in the process known to as excitation-contraction (EC) coupling. In contrast, the late effects involve a process that is, by analogy, referred to as excitation-transcription (ET) coupling. This process involves activation of gene expression by Ca2+. In this scheme, specific and localised elevations of Ca2+ can be converted into changes in gene expression with long-term effects on the adaptation of the heart to a sustained stimulus. There is emerging evidence of an extraordinary diversity of responses, depending on the location, intensity, and duration of Ca2+ signals that can be activated during pathology. Whereas alterations of cellular and molecular mechanisms underlying chronic pathology are relatively well defined, the initial changes and their hierarchy are unknown. However, the actual picture suggests promising perspectives for new therapeutic interventions on old targets or new strategies. Some of these aspects are reviewed here.

Voltage-gated Ca2+ currents in the human pathophysiologic heart: a review

The L-type Ca2+ current (I(Ca-L)) plays a key role in the cardiac excitation-contraction (E-C) coupling. Thus, it is a major target for many transmitters and hormones modulating cardiac function and, therefore, for pharmacological drugs to regulate inotropy. Ca2+ (and other) ion currents are commonly studied in animal tissues for practical reasons. Investigations in human cardiomyocytes started extensively only ten years ago with the development of patch-clamp techniques, enzymatic cell dissociation procedures, and surgical techniques. These studies have already provided valuable information concerning the nature, biophysics, pharmacology and regulation of human cardiac ionic currents in normal and diseased tissues. Interesting advances have been made to understand the role of I(Ca-L) in the development of chronic atrial fibrillation (AF). Alterations of single channel activity and regulation of macroscopic I(Ca-L) have also been found in heart failure (HF), ugh some of the data are divergent and puzzling. The T-type Ca2+ current (I(Ca-T)) has never been recorded in human cardiomyocytes. After a rapid overview of the basic properties of human cardiac Ca2+ currents, we focus on selected aspects of pathophysiology that are still unsolved.

Clinical and genetic studies of Birt-Hogg-Dubé syndrome

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant cancer syndrome characterised by benign skin tumours, renal tumours, and spontaneous pneumothorax. The gene has been mapped to chromosome 17p11.2 and recently identified, expressing a novel protein called folliculin. We report the clinical and genetic studies of four sporadic BHD cases and four families with a total of 23 affected subjects. Haplotype analysis of these families using BHD linked markers showed they did not share the same affected alleles, excluding common ancestry. Mutation analysis of the BHD gene identified two germline mutations on exon 11 (c.1733insC and c.1733delC) in three of four families as well as two of four sporadic cases. A novel somatic mutation, c.1732delTCinsAC, was detected in a BHD related chromophobe renal carcinoma. Our results confirmed the (C)8 tract in exon 11 as a mutational hot spot in BHD and should always be considered for future genetic testing. Our observation also indicated that the second hit (of Knudson's two hit theory) in some BHD related tumours is in the form of somatic mutation rather than LOH. In a large French family in which eight affected subjects carry the c.1733delC mutation, a phenocopy who has multiple episodes of spontaneous pneumothorax was identified. A total of five mutation carriers (aged between 37 to 66) did not have any evidence of BHD features, suggesting either reduced penetrance or late age of onset of the disease. In addition, six out of eight affected subjects who have positive germline mutation have confirmed neoplastic colonic polyps, indicating that colorectal neoplasia is an associated feature of BHD in some families. Our studies have observed several interesting genetic features in BHD: (1) the poly (C) tract in exon 11 as a mutational hot spot; (2) the existence of phenocopy; (3) reduced penetrance or late age of onset of disease; (4) association with colorectal neoplasia in some families; and (5) somatic mutation instead of LOH as the second hit in BHD tumours.

Liver function tests in sickle cell disease

We investigated the prevalence of positive viral hepatitis titres in sickle cell disease (SCD) and the relationship of abnormal liver function tests (LFTs) to transfusions and ferritin levels. Charts from 141 patients with SCD were reviewed and recent laboratory data on serum ferritin, hepatitis serology, units of packed red blood cells transfused and LFTs were collected. Hepatitis B core antibodies were positive in 14% of patients (12/86) and Hepatitis C viral antibody titres were positive in 16.5% (15/91). There was a relationship of positive serologies to transfusion for hepatitis C virus (HCV), but not for hepatitis B virus (HBV). Hepatitis C antibody negative (HCVAb-) patients had fewer packed red blood cells (pRBC) transfused than Hepatitis C antibody positive (HCVAb+) (6.4 vs. 20.3, P=0.08). Patients with ferritins < 500 ng/ml compared to those with > 1000 ng/ml also showed a difference in units transfused (P < 0.003). Steady state LFTs, with the exception of alkaline phosphatase, had no relationship to serum ferritin or hepatitis serologies. Males were twice as likely to have positive serology as females but more females had elevated ferritin levels. Paired analysis of LFTs in steady state and crisis failed to demonstrate deterioration during crisis. We conclude that: (1) there is a relationship of positive Hepatitis C serology, but not Hepatitis B serology, to transfusion; (2) ferritin levels correlate with transfusion number but not with LFTs; (3) in our population, LFTs in SCD are usually normal and do not increase in vaso-occlusive crises.

Atom laser divergence

We measure the angular divergence of a quasicontinuous, rf-outcoupled, free-falling atom laser as a function of the outcoupling frequency. The data are compared to a Gaussian-beam model of laser propagation that generalizes the standard formalism of photonic lasers. Our treatment includes diffraction, magnetic lensing, and interaction between the atom laser and the condensate. We find that the dominant source of divergence is the condensate-laser interaction.

Inhibition of human immunodeficiency virus type 1 Rev function by a dominant-negative mutant of Sam68 through sequestration of unspliced RNA at perinuclear bundles

Human immunodeficiency virus (HIV) type 1 encodes an essential protein, Rev, which functions to transport unspliced and singly spliced viral transcripts from the nucleus to the cytoplasm to allow expression of the viral structural proteins. It has previously been reported that Sam68 synergistically stimulates Rev activity (T. Reddy et al., Nat. Med. 5:635-642, 1999). Here we report that the Sam68-like mammalian proteins SLM1 and SLM2 also stimulate Rev activity. Their stimulation ability cannot be attributed to a shuttling property, since Sam68, SLM1, and SLM2 do not display significant shuttling activity alone or in the presence of Rev. In addition, Sam68, SLM1, and SLM2 do not affect the equilibrium between unspliced and completely spliced HIV RNA. The C-terminally truncated Sam68 mutant (Sam68DeltaC) previously observed to inhibit the Sam68-mediated stimulation of Rev activity (Reddy et al., 1999) also inhibits SLM1- and SLM2-mediated stimulation of Rev activity. This suggests that the mechanism by which Sam68, SLM1, and SLM2 stimulate Rev activity may be common. Sam68DeltaC does not inhibit Rev activity by inhibiting Rev from shuttling between the nucleus and cytoplasm. Inhibition by Sam68DeltaC is a consequence of its mislocalization to the cytoplasm, as evidenced by the fact that addition of an exogenous nuclear localization signal to Sam68DeltaC restores nuclear localization and stimulation of Rev activity. We demonstrate that Sam68DeltaC causes perinuclear accumulation of unspliced HIV env RNA and propose that Sam68DeltaC inhibits Rev activity by sequestering Rev-responsive RNA away from the translation apparatus.

Effects of the combination of camptothecin and doxorubicin or etoposide on rat glioma cells and camptothecin-resistant variants

From the rat C6 glioma cell line in culture, we selected camptothecin-resistant variants by growth in the presence of increasing amounts of this drug (C6(CPT10), C6(CPT50)and C6(CPT100), growing respectively with 10, 50 and 100 ng ml(-1)camptothecin). The degree of resistance to camptothecin ranged between 15-fold (C6(CPT10)) and 30-fold (C6(CPT50)and C6(CPT100)). The C6(CPT10)cell line presented a collateral sensitivity to etoposide (3.6-fold), while the C6(CPT50)and C6(CPT100)cell lines were cross-resistant to etoposide (1.8-fold) The resistant lines were characterised by a two-fold reduced content and catalytic activity of topoisomerase I, and C6(CPT50)and C6(CPT100)presented a significant increase in topoisomerase IIalpha content and catalytic activity and a marked overexpression of P-glycoprotein. We explored the cytotoxicity of combinations of a topoisomerase I inhibitor (camptothecin) and a topoisomerase II inhibitor (doxorubicin or etoposide) at several molar ratios, allowing the evaluation of their synergistic or antagonistic effects on cell survival using the median effect principle. The simultaneous combination of camptothecin and doxorubicin or etoposide was additive or antagonistic in C6 cells, slightly synergistic in the C6(CPT10)line and never more than additive in the C6(CPT50)and C6(CPT100)cell lines. The sequential combination of doxorubicin and camptothecin gave additivity in the order camptothecin --> doxorubicin and antagonism in the order doxorubicin --> camptothecin. Clinical protocols combining a topoisomerase I and a topoisomerase II inhibitor should be considered with caution because antagonistic effects have been observed with combinations of camptothecin and doxorubicin.

Identification of Sam68 arginine glycine-rich sequences capable of conferring nonspecific RNA binding to the GSG domain

Sam68 is an RNA-binding protein that contains a heterogeneous nuclear ribonucleoprotein K homology domain embedded in a larger RNA binding domain called the GSG (GRP33, Sam68, GLD-1) domain. This family of proteins is often referred to as the STAR (signal transduction and activators of RNA metabolism) proteins. It is not known whether Sam68 is a general nonspecific RNA-binding protein or whether it recognizes specific response elements in mRNAs with high affinity. Sam68 has been shown to bind homopolymeric RNA and a synthetic RNA sequence called G8-5 that has a core UAAA motif. Here we performed a structure function analysis of Sam68 and identified two arginine glycine (RG)-rich regions that confer nonspecific RNA binding to the Sam68 GSG domain. In addition, by using chimeric proteins between Sam68 and QKI-7, we demonstrated that one of the Sam68 RG-rich sequences of 26 amino acids was sufficient to confer homopolymeric RNA binding to the GSG domain of QKI-7, another STAR protein. Furthermore, that minimal sequence can also give QKI-7 the ability (as Sam68) to functionally substitute for HIV-1 REV to facilitate the nuclear export of RNAs. Our studies suggest that neighboring RG-rich sequences may impose nonspecific RNA binding to GSG domains. Because the Sam68 RNA binding activity is negatively regulated by tyrosine phosphorylation, our data lead us to propose that Sam68 might be a specific RNA-binding protein when tyrosine phosphorylated.

God in control: women's perspectives on managing HIV infection

Women with HIV face a number of challenges in living with this chronic, life-threatening illness: economic, physical, social, and emotional. When discussing their illness the importance these women place on having a strong spiritual life is a consistent theme. In this study, women were asked to describe and explain what spirituality meant to them and how they used it in living with HIV. The results indicate that, in opposition to what some contemporary providers fear HIV-positive women use their spiritual life to enhance the care prescribed by providers, rather than using their faith to avoid mainstream sources of care. In addition, women related the importance of spirituality in dealing with everyday life. Knowledgeable providers can incorporate discussions of spirituality in their care of women with HIV and, in the process, potentially improve the therapeutic results of their HIV-specific care.

Rapid stimulatory effects of brain-derived neurotrophic factor and neurotrophin-3 on somatostatin release and intracellular calcium rise in primary hypothalamic cell cultures

Although the long-lasting effects of neurotrophins have been extensively studied, less data are available on their rapid effects, especially on peptide release. In the present report, we investigated rapid effects of neurotrophins on somatostatin release and on intracellular calcium concentration ([Ca(2+)](i)) in primary cultures of hypothalamic neurons. RT-PCR experiments revealed mRNA expression of the three high-affinity neurotrophin receptors tyrosine kinase (Trk) TrkA, TrkB and TrkC, indicating potential responses to their preferential ligands: nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT-3), respectively. We demonstrated that BDNF, and to a lesser extent NT-3, induced significant time- and concentration-dependent somatostatin release, while NGF was devoid of any effect. BDNF or NT-3 induction of somatostatin release was inhibited by the Trk inhibitors K-252a and genistein, whereas K-252b, a less effective inhibitor, had no effect. BDNF- and NT-3-induced somatostatin release depended upon extra- and intracellular Ca(2+) since it was completely abolished in the presence of the Ca(2+) chelators BAPTA (bis-(alpha-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid) or BAPTA-AM (bis-(alpha-aminophenoxy)-ethane-N,N,N',N'-tetraacetoxymethylester), respectively. In addition, BDNF and NT-3 induced a sustained and rapid increase in [Ca(2+)](i) which depended on the extracellular Ca(2+) concentration. MK-801 (dizocilpine) and tetrodotoxin (TTX) entirely blocked neurotrophin-evoked somatostatin release and [Ca(2+)](i) rise in response to BDNF and NT-3 application in most neurons. Neurotrophin-induced [Ca(2+)](i) rise was completely blocked by K-252a. The present results are consistent with: (1) an indirect effect of neurotrophins on somatostatin release via endogenous glutamate release and subsequent NMDA receptor activation, (2) a major indirect effect of neurotrophins on Ca(2+) rise in hypothalamic neurons which very likely occurs through NMDA receptor activation. Taken altogether, these results indicate that BDNF and NT-3 can rapidly affect the activity of hypothalamic neurons.

Role of cellular zinc in programmed cell death: temporal relationship between zinc depletion, activation of caspases, and cleavage of Sp family transcription factors

Zinc is a potent inhibitor of apoptosis, whereas zinc depletion induces apoptosis in many cell lines. To investigate the mechanisms of zinc depletion-induced apoptosis, HeLa cells were treated with the membrane permeable metal ion chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN). TPEN decreased the intracellular level of zinc and induced apoptosis with a characteristic cellular pattern, i.e. cell shrinkage and formation of apoptotic bodies, with DNA fragmentation and formation of a typical DNA ladder pattern. Following TPEN treatment, caspases-3, -8, and -9 were activated and caspase target proteins, poly(ADP-ribose) polymerase, and Sp transcription factors were cleaved. These effects were inhibited by adding zinc to the medium. To assess the role of zinc in the activation of the caspase cascade, we compared zinc inhibition during tumor necrosis factor alpha/cycloheximide- and etoposide-induced apoptosis with that induced by TPEN. Zinc addition partially inhibited caspase-3 activation, but not caspase-8 and -9 cleavage in HeLa cells treated with tumor necrosis factor alpha or etoposide. These results suggest that caspase-3 is rapidly and directly activated by zinc chelation, without a requirement for an upstream event. Caspase-3 activation is therefore the main event leading to apoptosis after intracellular zinc chelation. Finally, we conclude that cellular zinc inhibits apoptosis by maintaining caspase-3 inactive.

Inhibition of T-type and L-type calcium channels by mibefradil: physiologic and pharmacologic bases of cardiovascular effects

Ca2+ channel antagonists of the dihydropyridine, benzothiazepine, and phenylalkylamine classes have selective effects on L-type versus T-type Ca2+ channels. In contrast, mibefradil was reported to be more selective for T-type channels. We used the whole-cell patch-clamp technique to investigate the effects of mibefradil on T-type and L-type Ca2+ currents (I(CaT) and I(CaL)) recorded at physiologic extracellular Ca2+ in different cardiac cell types. At a stimulation rate of 0.1 Hz, mibefradil blocked I(CaT) evoked from negative holding potentials (HPs) (-100 mV to -80 mV) with an IC50 of 0.1 microM in rat atrial cells. This concentration had no effect on I(CaL) in rat ventricular cells (IC50: approximately3 microM). However, block of I(CaL) was enhanced when the HP was depolarized to -50 mV (IC50: approximately 0.1 microM). Besides a resting block, mibefradil displayed voltage- and use-dependent effects on both I(CaT) and I(CaL). In addition, inhibition was enhanced by increasing the duration of the step-depolarizations. Similar effects were observed in human atrial and rabbit sinoatrial cells. In conclusion, mibefradil combines the voltage- and use-dependent effects of dihydropyridines and benzothiazepines on I(CaL). Inhibition of I(CaL), which has probably been underestimated before, may contribute to most of the cardiovascular effects of mibefradil.

Nuclear translocation controlled by alternatively spliced isoforms inactivates the QUAKING apoptotic inducer

The quaking viable mice have myelination defects and develop a characteristic tremor 10 d after birth. The quaking gene encodes at least five alternatively spliced QUAKING (QKI) isoforms that differ in their C-terminal 8--30-amino-acid sequence. The reason for the existence of the different QKI isoforms and their function are unknown. Here we show that only one QKI isoform, QKI-7, can induce apoptosis in fibroblasts and primary rat oligodendrocytes. Heterodimerization of the QKI isoforms results in the nuclear translocation of QKI-7 and the suppression of apoptosis. The unique C-terminal 14 amino acids of QKI-7 confers the ability to induce apoptosis to heterologous proteins such as the green fluorescent protein and a QKI-related protein, Caenorhabditis elegans GLD-1. Thus, the unique C-terminal sequences of QKI-7 may function as a life-or-death 'sensor' that monitors the balance between the alternatively spliced QKI isoforms. Moreover, our findings suggest that nuclear translocation is a novel mechanism of inactivating apoptotic inducers.

Cyclosporin A increases basal intracellular calcium and calcium responses to endothelin and vasopressin in human coronary myocytes

Cyclosporin A (CsA) is a widely used immunosuppressive agent with severe side effects including hypertension. Here, we investigated the effects of CsA on intracellular free calcium ([Ca(2+)](i)) and the mechanisms involved in vasoconstriction in cultured human coronary myocytes. We used the Fura-2 technique for Ca(2+) imaging. Acute application of CsA at therapeutic concentrations (0.1-10 micromol/l) had no effect. Chronic exposure to CsA (1 micromol/l) for 24 h induced a small (20 nmol/l) but highly significant increase of basal [Ca(2+)](i) and enhanced the occurrence of spontaneous Ca(2+) oscillations. Endothelin- and vasopressin-induced rises of [Ca(2+)](i) were also enhanced. The demonstration that CsA increases basal [Ca(2+)](i) in addition to its impact on agonist receptor stimulation is of major importance for new therapeutic approaches.

Comparative antihypertensive and renoprotective effects of telmisartan and lisinopril after long-term treatment in hypertensive diabetic rats

This study compared the cardiovascular and renal effects of long-term telmisartan (3 and 10 mg/kg/day)and lisinopril (10 mg/kg/day) in an animal model combining hypertension and diabetes mellitus. It was a parallel-group study of diabetic, spontaneously hypertensive rats (SHR), treated with control or active treatment for eight months. A non-diabetic SHR control group was run in parallel. Diabetes was induced by streptozotocin (45 mg/kg i.v.) in SHRs aged 9-10 weeks. Animals were treated with telmisartan (3 or 10mg/kg/day), lisinopril (10 mg/kg/day) or vehicle. Plasma glucose levels, blood pressure (BP), and urinary protein and albumin excretion were measured monthly. Telmisartan treatment significantly reduced BP of diabetic SHRs in a dose-dependent manner (p<0.05, low-dose, n= 18; p<0.01, high-dose, n=15). The BP reduction in the lisinopril group was similar to that in the telmisartan 10 mg/kg/day group. Compared with non-diabetic SHRs, untreated diabetic SHRs developed severe proteinuria and albuminuria over the experimental period (p<0.01). In diabetic SHRs, proteinuria and albuminuria were dose-dependently and significantly attenuated by treatment with telmisartan (p<0.01 with the higher dose) and lisinopril (p<0.01). Compared with the untreated diabetic SHRs, cardiac hypertrophy was significantly reduced after treatment with both doses of telmisartan and with lisinopril. Telmisartan, 10 mg/kg/day, but not lisinopril, significantly attenuated the diabetes-induced increase in glomerular volume. In conclusion, telmisartan, 10 mg/kg/day, is at least as beneficial as lisinopril, 10 mg/kg/day, in lowering BP, reducing cardiac hypertrophy and attenuating renal excretion of protein and albumin in this model.

[Prevention of renal carcinoma: the nutri-genetic approach]

The development of renal cell carcinoma (RCC) has been associated with both genetic and environmental factors, with somatic and germline mutations in the von Hippel-Lindau (VHL) tumor suppressor gene and with tobacco smoking, obesity, long term exposure to some nutrients, pollutants, and industrial solvents such as trichloroethylene. Intra and interfamilial variability of expression of germline mutations in the VHL gene and variable susceptibility to carcinogens in the sporadic forms strongly suggest the involvement of conditional modifier genes. In order to identify sub groups of individuals at increased risk because of susceptibility genotypes, we have collected a series of 460 patients who developed an RCC and 79 families with the von Hippel Lindau disease. To collect clinical and mutational data for correlation analysis we have developed a unique tool the Universal Mutation Database. Comparison of the spectrum of germline and somatic mutations in the VHL gene showed that: 1) in sporadic RCC mutations lead more often to truncated proteins (83%), while the remaining mutations (17%), include 3/4 of transversions and 1/4 of transitions. This high proportion of transversions supports the involvement of carcinogens the impact of which is conditioned by the genetic variability of xenobiotic metabolizing enzymes; 2) whereas in familial cases missense mutations are more common; this difference allowed us to define a prognostic factor for the occurrence of RCC in a VHL context. In order to look for genotypes conferring a higher risk we genotyped the RCC patients for 8 different genes (50 genotypes). A significant relationship was observed for several combinations of alleles including CYP1A1 ("variant"), NAT2 and NAT1 (slow) and GSTM1 (null allele). Associations between specific mutational profiles and at risk genotypes at different tumoral stages should allow us to: 1) define more precisely the nature of specific patterns of mutations in relation with the deficiency or overexpression of such or such enzymes in presence of particular carcinogens; 2) demonstrate that certain combinations of genotypes confer a particular risk to develop a specific type of tumor in VHL patients. Thus tracking of potentially carcinogenic substances, through their footprints and through identification of conditionally detrimental genotypes of genes participating in their detoxification should permit a better prevention through an appropriate nutrition adapted to each individual.

Transient down-regulation of L-type Ca(2+) channel and dystrophin expression after balloon injury in rat aortic cells

OBJECTIVE

Migration and proliferation of arterial smooth muscle cells are critical responses during restenosis after balloon angioplasty. We investigated the changes in the expression of Ca(2+) channels and dystrophin, two determinants of contraction, after balloon injury of rat aortas.

METHODS

Proliferation and migration of aortic myocytes were triggered in vivo by the passage of an inflated balloon catheter in the aortas of 12-week-old male Wistar rats. We used the whole-cell patch clamp technique to investigate Ba(2+) currents (I(Ba)) through Ca(2+) channels in single cells freshly isolated from media and neointima at various times after injury (days 2, 7, 15, 30 and 45).

RESULTS

No T-type Ca(2+) channel current was recorded in any cell at any time. In contrast, a dihydropyridine (DHP)-sensitive L-type I(Ba)was recorded consistently in the media of intact aorta. After aortic injury, I(Ba) decreased dramatically (at days 2 and 7) but recovered over time to reach normal amplitude on days 30 and 45. In the neointima, I(Ba) was absent on day 15 but also increased gradually over time as observed at days 30 and 45. The use of a specific antibody directed against the L-type Ca(2+) channel alpha(1C) subunit showed, both by immunostaining and by Western blotting, no expression of the Ca(2+) channel protein on day 15. Parallel immunodetection of dystrophin showed that this marker of the contractile phenotype of SMCs was also not detectable at this stage in neointimal cells. Both proteins were re-expressed at days 45 and 63. Balloon injury induces a transient down-regulation of I(Ba) in arterial cells.

CONCLUSIONS

Cell dedifferentiation and proliferation in vivo abolish the expression of L-type Ca(2+) channels and dystrophin in neointimal cells. These changes may be critical in the regulation of Ca(2+) homeostasis and, thereby, contraction of the arterial SMCs during restenosis following angioplasty.

Facilitation of the L-type calcium current in rabbit sino-atrial cells: effect on cardiac automaticity

OBJECTIVE

The L-type Ca(2+) current (I(Ca,L)) contributes to the generation and modulation of the pacemaker action potential (AP). We investigated facilitation of I(Ca,L) in sino-atrial cells.

METHODS

Facilitation was studied in regularly-beating cells isolated enzymatically from young albino rabbits (0.8-1 kg). We used the whole-cell patch-clamp technique to vary the frequency of the test depolarizations evoked at -10 mV or the conditioning diastolic membrane potential prior to the test pulse.

RESULTS

High frequencies (range 0.2-3.5 Hz) slowed the decay kinetics of I(Ca,L) evoked from a holding potential (HP) of -80 mV in 68% of cells resulting in a larger Ca(2+) influx during the test pulse. The amount of facilitation increased progressively between 0.2 and 3.0 Hz. When the frequency was changed from 0.1 to 1 Hz, the averaged increase in the time integral of I(Ca,L) was 27+/-7% (n=22). Application of conditioning voltages between -80 and -50 mV induced similar facilitation of I(Ca,L) in 73% of cells. The maximal increase of Ca(2+) entry occurred between -60 and -50 mV, and was on average 38+/-14% for conditioning prepulses of 5 s in duration (n=15). Numerical simulations of the pacemaker activity showed that facilitation of I(Ca,L) promotes stability of sino-atrial rate by enhancing Ca(2+) entry, thus establishing a negative feedback control against excessive heart rate slowing.

CONCLUSION

Facilitation of I(Ca,L) is present in rabbit sino-atrial cells. The underlying mechanism reflects modulation of I(Ca,L) decay kinetics by diastolic membrane potential and frequency of depolarization. This phenomenon may provide an important regulatory mechanism of sino-atrial automaticity.

An immunological syndrome featuring transverse myelitis, Evans syndrome and pulmonary infiltrates after unrelated bone marrow transplant in a patient with severe aplastic anemia

A patient with severe aplastic anemia underwent a matched unrelated bone marrow transplant, following which he developed a complex autoimmune syndrome. This featured transverse myelitis, immune mediated Coombs positive hemolytic anemia and immune thrombocytopenia (Evans syndrome), pulmonary infiltrates, eosinophilia, muscle pains and cramps and lichenoid dermatitis all of which may represent manifestations of graft-versus-host disease as they showed response to immunosuppression. Thus, although immune-mediated cytopenias after an allogeneic bone marrow transplant are rare, they should be considered as a possible cause of cytopenia in post-transplant patients.

What some effects might not be: the time to verify membership in "well-defined" categories

Armstrong, Gleitman, and Gleitman (1983) reported shorter categorization times for members of well-defined categories judged more typical. They concluded that these effects could not originate in a graded, similarity-based category representation and consequently that the typicality effects obtained with natural categories might not be indicative of such a structure either. In this article, we re-examine this conclusion, focusing first on the performance obtained with well-defined categories of different sizes. Only the larger categories used showed variations in typicality ratings and produced typicality effects on categorization times. However, multiple regression analyses showed the effects on categorization times to be better explained by a measure of associative strength, called category dominance. The range of various predictor variables was equated in a follow-up experiment involving large, natural, and well-defined categories. Results obtained with well-defined categories showed pronounced dominance effects when typicality was controlled, but no reliable typicality effect when category dominance and instance familiarity were controlled. Results were opposite for natural categories. By showing that well-defined categories fail to produce unbiased typicality effects, our results bring added support to the hypothesis that the effects obtained with natural categories originate in a graded, similarity-based category structure.

HCaRG, a novel calcium-regulated gene coding for a nuclear protein, is potentially involved in the regulation of cell proliferation

Since a negative calcium balance is present in spontaneously hypertensive rats, we searched for the gene(s) involved in this dysregulation. A cDNA library was constructed from the spontaneously hypertensive rat parathyroid gland, which is a key regulator of serum-ionized calcium. From seven overlapping DNA fragments, a 1100-base pair novel cDNA containing an open reading frame of 224 codons was reconstituted. This novel gene, named HCaRG (hypertension-related, calcium-regulated gene), was negatively regulated by extracellular calcium concentration, and its basal mRNA levels were higher in hypertensive animals. The deduced protein showed no transmembrane domain, 67% alpha-helix content, a mutated calcium-binding site (EF-hand motif), four putative "leucine zipper" motifs, and a nuclear receptor-binding domain. At the subcellular level, HCaRG had a nuclear localization. We cloned the human homolog of this gene. Sequence comparison revealed 80% homology between rats and humans at the nucleotide and amino acid sequences. Tissue distribution showed a preponderance in the heart, stomach, jejunum, kidney (tubular fraction), liver, and adrenal gland (mainly in the medulla). HCaRG mRNA was significantly more expressed in adult than in fetal organs, and its levels were decreased in tumors and cancerous cell lines. We observed that after 60-min ischemia followed by reperfusion, HCaRG mRNA declined rapidly in contrast with an increase in c-myc mRNA. Its levels then rose steadily to exceed base line at 48 h of reperfusion. HEK293 cells stably transfected with HCaRG exhibited much lower proliferation, as shown by cell count and [(3)H]thymidine incorporation. Taken together, our results suggest that HCaRG is a nuclear protein potentially involved in the control of cell proliferation.

Pancreatic involvement in von Hippel-Lindau disease. The Groupe Francophone d'Etude de la Maladie de von Hippel-Lindau

BACKGROUND & AIMS

Pancreatic involvement in von Hippel-Lindau (VHL) disease, a genetic disorder with a dominant mode of inheritance affecting various organs, has rarely been studied. We assessed the prevalence, type of lesions, natural history, and impact of pancreatic involvement in patients with VHL.

METHODS

A total of 158 consecutive patients from 94 families with VHL disease were studied in a prospective French collaborative study. All patients underwent systematic screening for VHL lesions, including computerized tomography (CT) scanning of the pancreas reviewed by an experienced radiologist. Clinical data, investigations, and treatments performed were also reviewed.

RESULTS

Pancreatic involvement was observed in 122 patients (77.2%) and included true cysts (91.1%), serous cystadenomas (12.3%), neuroendocrine tumors (12.3%), or combined lesions (11.5%). The pancreas was the only organ affected in 7.6% of patients. Patients with pancreatic lesions had fewer pheochromocytomas than those without (14/122 vs. 16/36; P<0.0001), and patients with neuroendocrine pancreatic tumors had renal involvement less often than those without (8/99 vs. 6/20; P = 0.013). None of the patients with neuroendocrine tumors had symptoms of hormonal hypersecretion. Pancreatic lesions evolved in half of patients but required specific treatment in only 10 (8.2%) when they were symptomatic or for the resection of large neuroendocrine tumors.

CONCLUSIONS

Pancreatic involvement is seen in most patients with VHL disease. Although symptoms are rare, specific treatment of pancreatic lesions is required in selected patients, mainly those with neuroendocrine tumors.

Serum levels of YKL-40 and C reactive protein in patients with hip osteoarthritis and healthy subjects: a cross sectional study

BACKGROUND

YKL-40 is a 40 kDa glycoprotein secreted by chondrocytes and synoviocytes. It has been suggested that it is a surrogate marker of synovial inflammation and joint destruction in rheumatoid arthritis (RA) and osteoarthritis (OA) and related to C reactive protein (CRP) serum levels in RA.

OBJECTIVE

To study serum levels of YKL-40 in patients with hip OA and its relation with CRP.

METHODS

YKL-40 and CRP were assayed in serum samples from 45 patients (24 women, 21 men, mean age 65) with symptomatic OA of the hip and 33 healthy controls. YKL-40 was assayed by immunoassay and CRP by ultrasensitive immunonephelometry. OA severity was assessed by the measurement of joint space width with a computer analysis system of digitised hip radiographs. Statistical analysis was performed to determine correlations between serum markers and radiological joint space width.

RESULTS

The mean (standard error) YKL-40 level was 90.3 (8.2) ng/ml in patients with hip OA and 66.9 (8.2) ng/ml in controls (p=0.03). The mean CRP level was 2.93 (3.03) mg/l in OA and 1.40 (1.61) mg/l in controls (p=0.006). The serum levels of YKL-40 and CRP increased with age and were significantly correlated (Spearman test: r(s)=0.42, p=0.005) in patients but not in controls. Neither YKL-40 nor CRP correlated with radiographic joint space width.

CONCLUSIONS

Serum YKL-40 was significantly increased in patients with hip OA. The correlation between YKL-40 and CRP suggests that YKL-40 may be a marker of joint inflammation in OA. Longitudinal studies are required to assess the usefulness of YKL-40 in the monitoring of patients with hip OA.

Comparison of methyl anthranilate and denatonium benzoate as aversants for learning in chicks

Methyl anthranilate (MeA) has been widely used as a taste aversant for domestic chicks in the one-trial passive avoidance learning (PAL) task. However, MeA has a strong smell that may be aversive to chicks. Therefore, odourless denatonium benzoate (DB) has been suggested as an alternative taste aversant in PAL. The present study was designed to compare the efficacy of MeA and DB as aversants in the one-trial PAL task. In this task, young chicks peck a visually conspicuous bead coated with a taste aversant and in a single trial learn to avoid a similar, but uncoated bead at subsequent presentation. In Experiment 1, chicks were trained using a silver-coloured bead coated with 100% MeA, 0.5% DB or distilled water. After 3 h, MeA-trained, but not DB-trained chicks, exhibited significantly higher avoidance of the test bead than water-trained chicks. In Experiment 2, three pre-training presentations of an uncoated red bead preceded training with the silver bead. MeA-trained chicks showed significantly higher avoidance of the test bead than water-trained chicks. The numbers of water- and DB-trained chicks that avoided pecking the test bead were low and not significantly different from each other. However, DB-trained chicks exhibited significantly longer latencies to peck the test bead than water-trained chicks, indicating that they had retained some memory of the task. Thus, 0.5% DB is a weaker aversant than MeA and it does not induce high levels of learning in the one-trial PAL task. However, DB may prove useful for investigating weakly reinforced learning.

The organization of the striatal output system: a single-cell juxtacellular labeling study in the rat

The aim of the present study was to provide a detailed account of the axonal branching pattern of striatal projection neurons in the rat. Seventy-seven striatofugal neurons were singly labeled following juxtacellular injection of biotin dextran amine. Their axons were entirely reconstructed along the sagittal plane with the help of a light microscope equipped with a camera lucida. The major findings of this study can be summarized as follows, (1) the striatofugal system originates from medium-sized spiny neurons that project only to globus pallidus (GP, type I, 36.4%), to both GP and substantia nigra pars reticulata (SNr, type II, 26%), or to globus pallidus, entopeduncular nucleus (EP) and SNr (type III, 37.6%); (2) the striatofugal system displays a high degree of axonal collateralization; about two-thirds of its axons arborize into two or three striatal target structures; (3) virtually all striatofugal axons send collaterals to the GP and none project exclusively to the EP and or SNr; (4) the three types of striatal projection neurons share similar somatodendritic morphology and have no preferential distribution in the dorsal striatum. These data, together with those of previous investigations, indicate that the striatofugal system can no longer be considered to be a simple dual (direct indirect) projection system. Instead, it stands out as a complex and widely distributed neuronal network whose elements are endowed with a highly patterned set of axon collaterals, which allows them to control in an exquisitely precise manner the flow of information along the main axis of the basal ganglia.

Renal lesions in Von Hippel-Lindau disease: the benign, the malignant, the unknown

OBJECTIVES

To describe the features and treatment of renal lesions in von Hippel-Lindau disease (VHL) from a series of patients, to highlight important issues in the management of these lesions.

MATERIALS AND METHODS

We performed a retrospective study in 7 patients with VHL who underwent surgery for renal lesions between January 1990 and July 1996. The initial evaluation consisted of an abdominal CT scan and renal arteriography.

RESULTS

The mean age of patients at the time of discovery was 38 (+/- 12.01 years). All cases were of type 1. Radiology assessment underestimated the gravity of the lesions in 5 patients. In all patients, unilateral surgery was performed with the kidney being conserved in 4 cases. Of the 44 lesions removed, 23 had signs of progressiveness (atypical or malignant cyst, renal cell carcinoma), most of the cancers were of low grade. 84% of the lesions did not exceed 3 cm and 48% were </=1 cm. During follow-up (42 months), 2 patients relapsed.

CONCLUSION

The clinical and pathological features of renal lesions in VHL require strict and early follow-up (from the age of 15). Only under these circumstances should primary conservative surgery be performed, however, recurrences are frequent. This conservative approach remains to be validated by multicentric prospective studies.

[Is atypical sodium current related to arterial pathophysiology?]

Primary cultured human coronary myocytes, derived from patients with end-stage heart failure (NYHA, classes III and IV) caused by an ischemic disease and undergoing heart transplantation, express a voltage-gated tetrodotoxin-sensitive sodium current (INa). This current has atypical electrophysiological and pharmacological properties and regulates intracellular sodium ([Na+]i) and calcium ([Ca2+]i). Our work is aimed at identifying its role and regulation of expression during pathophysiology. We currently investigate whether INa is expressed in vascular smooth muscles cells (VSMCs) isolated from either healthy or diseased (atheromatous) arteries in human and, in parallel, in pig, rabbit and rat. Cells were enzymatically isolated, primary cultured and macroscopic INa were recorded using the whole cell patch clamp technique. We found that INa is expressed in VSMCs grown from human aortic (90%; n = 48) and pulmonary (44%; n = 16) arteries and in the human aortic cell line HAVSMC (94%; n = 27). INa was also detected in pig coronary (60%; n = 25) and rabbit aortic (47%; n = 15) VSMCs, but not in rat aortic myocytes (n = 30). These different INa were activated at similar range of potentials (approximately -45 mV), had similar sensitivity to tetrodotoxin (IC50 around 5 nM) and similar density (2 to 4 pA/pF). Their expression was related to cell dedifferentiation in vitro. However, INa was observed more frequently in human myocytes derived from diseased arteries (ischemic cardiopathy) than in those derived from healthy tissues (dilated cardiopathy). In conclusion, INa may contribute to increase the basal arterial contractility and play a role in pathological situations including hypertension.

Effects of clomipramine hydrochloride on heart rate and rhythm in healthy dogs

OBJECTIVE

To determine the effects of clomipramine hydrochloride on heart rate and rhythm in dogs.

ANIMALS

17 healthy Beagles.

PROCEDURES

In experiment 1, 8 dogs received placebo or clomipramine (20 mg/kg of body weight, q 24 h, PO) for 7 days in a 2-way crossover design. In experiment 2, 9 dogs were evaluated for 48 hours before and 24 hours after oral administration of clomipramine (4 or 12 mg/kg) in a 2-way crossover design. Electrocardiogram and heart rate were monitored continuously by use of telemetry.

RESULTS

A significant diurnal rhythm in heart rate was detected; minimum values were recorded at night. Administration of 20 mg of clomipramine/kg induced a significant reduction in heart rate, with peak effect achieved approximately 12 hours after dosing. Administration of 4 or 12 mg of clomipramine/kg did not result in significant changes in heart rate. Sinoatrial and second-degree atrioventricular block and ventricular escape beats were observed during periods of slow heart rate in more dogs that received clomipramine (3 to 4 of 8 dogs), compared with dogs that received placebo (1 to 2 of 8 dogs), but this difference was not significant.

CONCLUSIONS AND CLINICAL RELEVANCE

Short-term administration of clomipramine induced benign cardiovascular effects in dogs rather than the potentially dangerous arrhythmias or tachycardia reported following administration of tricyclic antidepressants to humans. Precautions regarding cardiovascular effects may not be needed for the use of clomipramine in healthy dogs.

Induction of chalcone synthase expression in white spruce by wounding and jasmonate

The phenylpropanoid pathway has important functions in angiospermous plants following exposure to environmental stresses, such as wounding and pathogen attack, that lead to production of compounds including lignin, flavonoids and phytoalexins. Chalcone synthase (CHS) is a key enzyme in this pathway, catalyzing the first step in flavonoid biosynthesis, whose expression can be induced in response to environmental stress. To explore the response of conifers to environmental stress, expression of spruce CHS and its inducibility were investigated. A partial spruce CHS cDNA clone was isolated using PCR. Examination of the expression patterns of the CHS gene family in white spruce revealed accumulation of CHS mRNA in needle tissue following mechanical wounding, or application of signal molecules like jasmonic acid or methyl jasmonate. Repeated mechanical wounding or jasmonate applications had an enhancing effect on transcript accumulation in needles. A systemic accumulation of CHS mRNAs following wounding was also observed. Conifers thus appear to possess a general wound response similar to that found for angiosperms, which includes CHS induction as well as its inducibility by jasmonic acid and airborne methyl jasmonate.

Sik (BRK) phosphorylates Sam68 in the nucleus and negatively regulates its RNA binding ability

Sik (mouse Src-related intestinal kinase) and its orthologue BRK (human breast tumor kinase) are intracellular tyrosine kinases that are distantly related to the Src family and have a similar structure, but they lack the myristoylation signal. Here we demonstrate that Sik and BRK associate with the RNA binding protein Sam68 (Src associated during mitosis, 68 kDa). We found that Sik interacts with Sam68 through its SH3 and SH2 domains and that the proline-rich P3 region of Sam68 is required for Sik and BRK SH3 binding. In the transformed HT29 adenocarcinoma cell cell line, endogenous BRK and Sam68 colocalize in Sam68-SLM nuclear bodies (SNBs), while transfected Sik and Sam68 are localized diffusely in the nucleoplasm of nontransformed NMuMG mammary epithelial cells. Transfected Sik phosphorylates Sam68 in SNBs in HT29 cells and in the nucleoplasm of NMuMG cells. In functional studies, expression of Sik abolished the ability of Sam68 to bind RNA and act as a cellular Rev homologue. While Sam68 is a substrate for Src family kinases during mitosis, Sik/BRK is the first identified tyrosine kinase that can phosphorylate Sam68 and regulate its activity within the nucleus, where it resides during most of the cell cycle.

Facilitation of L-type calcium currents by diastolic depolarization in cardiac cells: impairment in heart failure

OBJECTIVE

Decay kinetics of the voltage-gated L-type Ca(2+) current (I(CaL)) control the magnitude of Ca(2+) influx during the cardiac action potential. We investigated the influence of changes in diastolic membrane potential on I(CaL) decay kinetics in cardiac cells.

METHODS

Cells were isolated enzymatically from rat ventricles, human right atrial appendages obtained during corrective heart surgery and left ventricles from end-stage failing hearts of transplant recipients. The whole-cell patch-clamp technique was used to evoke I(CaL) by a 100-ms depolarizing test pulse to -10 mV. Conditioning potentials between -80 and 0 mV were applied for 5 s prior to the test pulse.

RESULTS

Depolarizing the cells between -80 and -50 mV prior to the test pulse slowed the early inactivation of I(CaL) both in rat ventricular and human atrial cells. This slowing resulted in a significant increase of Ca(2+) influx. This type of facilitation was not observed when the sarcoplasmic reticulum (SR) Ca(2+) content was depleted using ryanodine which reduced the rate of inactivation of I(CaL), or when Ba(2+) replaced Ca(2+) as the permeating ion. Facilitation was favored by intracellular cAMP-promoting agents that, in addition to increasing current peak amplitude, enhanced the fast Ca(2+)-dependent inactivation of I(CaL). Facilitation was impaired in atrial and ventricular human failing hearts.

CONCLUSION

Decay kinetics of I(CaL) are regulated by the diastolic membrane potential in rat and human cardiomyocytes. This regulation, which associates slowing of I(CaL) inactivation with reduced SR Ca(2+) release and underlies facilitation of Ca(2+) channels activity, may have profound physiological relevance for catecholamines enhancement of Ca(2+) influx. It is impaired in failing hearts, possibly due to lowered SR Ca(2+) release.

Overexpression of T-type calcium channels in HEK-293 cells increases intracellular calcium without affecting cellular proliferation

Increased expression of low voltage-activated, T-type Ca(2+) channels has been correlated with a variety of cellular events including cell proliferation and cell cycle kinetics. The recent cloning of three genes encoding T-type alpha(1) subunits, alpha(1G), alpha(1H) and alpha(1I), now allows direct assessment of their involvement in mediating cellular proliferation. By overexpressing the human alpha(1G) and alpha(1H) subunits in human embryonic kidney (HEK-293) cells, we describe here that, although T-type channels mediate increases in intracellular Ca(2+) concentrations, there is no significant change in bromodeoxyuridine incorporation and flow cytometric analysis. These results demonstrate that expressions of T-type Ca(2+) channels are not sufficient to modulate cellular proliferation of HEK-293 cells.

Evaluation of fluorescein-labeled autologous leukocytes for examination of retinal circulation in humans

PURPOSE

Increased leukocyte-endothelium interaction have been suggested as a phenomenon contributing to capillary occlusion and/or rupture of the blood-retina barrier during human retinal vascular diseases. This study was performed to evaluate if fluorescein-labeled autologous leukocytes (FLALs) can be used for examination of leukocyte transit in the human retina.

METHODS

The preparation consisted of human dextran-separated leukocytes mixed with fluorescein. After reinjection in normal subjects and in one diabetic patient, a confocal scanning laser ophthalmoscope was used to visualize them in the retinal circulation. The changes between FLALs and control leukocytes in the expression of leukocytes adhesion molecules CD11b and CD62L were evaluated by flow cytometry.

RESULTS

The circulating FLALs were clearly visible in retinal vessels. The mean (+/- SD) capillaries velocity was 1.43 (+/- 1.3) mm/s in the macula and 1.82 (+/- 1.4) mm/s in the peripapillary area. No leukostasis was detected in the normal subjects, while it was detected in te diabetic patient. Flow cytometry revealed an increase in CD11b and a decrease in CD62L expression of leukocytes after labeling, suggesting that compared to normal leukocytes FLALs are more susceptible to interact with vascular endothelium.

CONCLUSIONS

The use of FLAL is presently the only technique applicable in humans for study of leukocyte transit in the retina. Their preparation is technically simple and unexpensive. Precise measurement of the velocity of leukocytes in small vessels can be obtained. Despite evidence of a certain degree of leukocyte activation after the labeling procedure, no leukostasis was detected in vivo in normal subjects. Potential applications for this technique may include the detection of leukostasis in the human retina during severe forms of diabetes and retinal phlebitis.

Pharmacokinetics of ketoprofen in rabbit after a single topical application

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used by topical application in management of joint pain and inflammation. Little is known, however, about their pharmacokinetics, especially in the synovial compartment versus the plasma compartment, following topical administration. Ketoprofen, a NSAID, was delivered by a single topical application (KETUM 2.5% gel) on the rabbit knee-joint region of one hind limb. Concentrations of ketoprofen were measured in plasma, synovial fluid, joint capsule and synovial fat tissue at 2, 4, 6 and 12 hours after application. Whatever the time period after application, ketoprofen concentrations in synovial fluid were much higher than in plasma. The time-course of the decrease in ketoprofen plasma concentrations was more rapid than that in synovial fluid. Similarly, concentrations in joint capsule were higher than those found in synovial fat tissue. Finally, while ketoprofen concentrations decreased rapidly in plasma and in synovial fat tissue, concentrations in joint capsule and particularly in synovial fluid were more sustained. The increase in residence time of ketoprofen in synovial fluid could be in favour of its efficiency in the management of joint pain and inflammation.

Germline mutation profile of the VHL gene in von Hippel-Lindau disease and in sporadic hemangioblastoma

von Hippel-Lindau (VHL) disease is a dominantly inherited disorder predisposing those afflicted to hemangioblastomas of the central nervous system and the retina, renal cell carcinomas, pheochromocytomas, and pancreatic tumors. The disease has been associated with mutations of the VHL gene. The screening of 92 unrelated patients with VHL disease for point mutations in this gene revealed 61 DNA variants. In addition, a search for EcoR1 rearrangements revealed germline anomalies in 5 patients. The 61 variants could be subdivided in 20 mutations predicted to alter the open reading frame (8 nonsense mutations, 8 frame shift mutations, and 4 mutations in consensus splicing sites) and 43 DNA sequence variants of a priori unknown biological consequence (4 in-frame insertions or deletions, 36 missense mutations, and 3 apparently silent variations). The 3' end of the coding sequence of the VHL gene, which encodes the Elongin binding domain was the site of 5 of 20 truncating mutations (25%) and of 18 of 41 DNA variants (44%) causing uncertain functional impairment. A similar screening in 18 patients with sporadic hemangioblastoma revealed 2 missense DNA variants. In order to corroborate this latter observation, a systematic screening for germline alteration of the VHL gene might be performed in a larger series of sporadic hemangioblastoma. If this preliminary result is confirmed, more than 10% of sporadic hemangioblastoma might be related to a mild VHL disease, thus a follow-up program similar to that recommended in cases of VHL disease should probably be discussed in the corresponding families.

Mutations of the VHL gene in sporadic renal cell carcinoma: definition of a risk factor for VHL patients to develop an RCC

To investigate the nature of somatic von Hippel-Lindau (VHL) mutations, we analyzed 173 primary sporadic human renal cell carcinomas for mutations of the VHL tumor suppressor gene, using polymerase chain reaction (PCR) and single-strand conformational polymorphism analysis (SSCP) of DNA. We detected abnormal SSCP pattern in 73 samples. After sequencing, we identified microdeletions in 58% of cases, microinsertions in 17%, nonsense mutations in 8%, and missense mutations in 17%. Among these mutations, 50% correspond to new mutations. VHL mutations were found only in the nonpapillary renal cell carcinoma (RCC) subtype, as previously reported. To compare somatic and germline mutations, we used the VHL database, which includes 507 mutations. The study of mutational events revealed a significant difference between somatic and germline mutations with mutations leading to truncated proteins observed in 78% of somatic mutations vs only 37% in germline mutations (P < 0.001). We postulated that a specific pattern of VHL mutations is associated with sporadic RCC. This pattern corresponds to mutations leading mainly to truncated proteins with few specific missense mutations. We then analyzed the occurrence of RCC in VHL families, based on the nature of mutations. We observed RCC in at least one member of the VHL families in 77% of cases with mutations leading to truncated proteins versus 55% in cases with missense mutations (P < 0.05). Thus, mutations resulting in truncated proteins may lead to a higher risk of RCC in VHL patients.

Arginine methylation inhibits the binding of proline-rich ligands to Src homology 3, but not WW, domains

Src homology 3 (SH3) and WW domains are known to associate with proline-rich motifs within their respective ligands. Here we demonstrate that the proposed adapter protein for Src kinases, Sam68, is a ligand whose proline-rich motifs interact with the SH3 domains of p59(fyn) and phospholipase Cgamma-1 as well as with the WW domains of FBP30 and FBP21. These proline-rich motifs, in turn, are flanked by RG repeats that represent targets for the type I protein arginine N-methyltransferase. The asymmetrical dimethylation of arginine residues within these RG repeats dramatically reduces the binding of the SH3 domains of p59(fyn) and phospholipase Cgamma-1, but has no effect on their binding to the WW domain of FBP30. These results suggest that protein arginine methylation can selectively modulate certain protein-protein interactions and that mechanisms exist for the irreversible regulation of SH3 domain-mediated interactions.

Isolation and characterization of a dehydrin gene from white spruce induced upon wounding, drought and cold stresses

A cDNA clone encoding a dehydrin gene was isolated from a cDNA library prepared from white spruce (Picea glauca) needle mRNAs. The cDNA, designated PgDhn1, is 1159 nucleotides long and has an open reading frame of 735 bp with a deduced amino acid sequence of 245 residues. The PgDhn1 amino acid sequence is highly hydrophilic and possesses four conserved repeats of the characterized lysine-rich K-segment (EKKGIMD-KIKEKLPG), and an 8-serine residue stretch prior to the first lysine-rich repeat that is common to many dehydrins. The DEYGNP conserved motif is, however, absent in the PgDhn1 sequence. In unstressed plants, the highest level of transcripts was detected in stem tissue and not fully expanded vegetative buds. PgDhn1 expression was also clearly detected in reproductive buds, at various stages of development. The mRNAs corresponding to PgDhn1 cDNA were induced upon wounding and by jasmonic acid (JA) and methyl jasmonate (MeJa) treatments. Upon drought stress, increased transcript accumulation was observed in needle tissue reaching a maximum level 48 h after treatment. Treatments of seedlings with abscisic acid or ethephon also resulted in high levels of transcript accumulation in needle tissue. Finally, cold induction of PgDhn1 transcripts was also detected as early as 8 h after treatment.

Evidence for tetrodotoxin-sensitive sodium currents in primary cultured myocytes from human, pig and rabbit arteries

Primary cultured human coronary myocytes express a tetrodotoxin-sensitive sodium current (I(Na)). Here, we have investigated whether I(Na) is expressed in vascular smooth muscles cells (VSMCs) isolated from other large arteries, and other mammals. VSMCs were enzymatically dissociated, kept in primary culture, and macroscopic I(Na) was recorded using the whole-cell patch-clamp technique. We found that I(Na) is expressed in VSMCs grown from human aortic (90%; n=50) and pulmonary (44%; n=19) arteries, and in the human aortic myocyte cell line HAVSMC (94%; n=27). I(Na) was also detected in pig coronary (60%; n=33), and rabbit aortic (47%; n=15), but not in rat aortic VSMCs (n=20). These different I(Na) had similar voltage thresholds for activation (approximately equal to -50 mV), and were highly sensitive to extracellularly applied tetrodotoxin. We conclude that I(Na) is expressed in VSMCs grown from various types of large arteries in humans, pig and rabbit.

Renal lesions in von Hippel-Lindau disease: immunohistochemical expression of nephron differentiation molecules, adhesion molecules and apoptosis proteins

AIMS

Renal lesions in von Hippel-Lindau disease comprise clear cell simple cysts, atypical cysts and carcinomas. Although histological and molecular studies suggest that cystic lesions may represent precursors of carcinomas, there is no detailed phenotypic evidence of their relationship.

METHODS AND RESULTS

To investigate such a possible relationship between cystic lesions and solid carcinomas, we studied the pathological and immunohistochemical features of 328 lesions of 33 kidneys originating from 23 patients with von Hippel-Lindau disease, using a panel of antibodies directed against cytoskeleton proteins, cell surface proteins, integrin subunits, adhesion molecules, lectins, and apoptosis and proliferation markers. Solid carcinomas (n = 175) were all of clear cell type and mostly nuclear grade 1. Cystic lesions (n = 138) consisted of cystic clear cell carcinomas (n = 15), atypical cysts (n = 20) and simple cysts (n = 103). Clear cells of the simple cysts, atypical cysts and solid carcinomas coexpressed cytokeratins (CK8, CK19) and vimentin, and expressed a similar pattern of tubular markers (CD24, tetraglonolobus), integrin subunits (alpha3, alpha5, alpha6, alphav, beta1) and cell adhesion molecules (ICAM 1, VCAM 1). In all lesions studied, proliferation rate (MIB1 index) was low, and apoptosis marker expression (fragmented DNA, p53, bcl-2) inconspicuous.

CONCLUSIONS

Phenotypic alterations found in solid renal cell carcinomas are already present in simple and atypical renal cysts of von Hippel-Lindau disease.