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Background: Western women frequently exhibit excessive gestational weight gain (GWG). The effects of maternal physical activity level (PAL) and body mass index (BMI) on the timing of GWG are insufficiently known., Purpose: To assess the impact of pre-pregnancy PAL and BMI on GWG during the second and third trimester and on birth weight., Methods: Body weight was measured in 223 healthy Swedish women in gestational weeks 12, 25 and 33, and GWG during the second (weeks 12-25) and third trimesters (weeks 25-33) was determined (kg/week). PAL was assessed using a questionnaire. Birth weights were obtained from birth records. The results were evaluated by the fitting of linear statistical models., Results: Some 50 and 80% of the women exhibited excessive GWG during the second and third trimesters, respectively. Women with a high pre-pregnancy PAL gained 0.10 kg/week (p=0.04) less weight during the third trimester than women with a medium PAL. A 5 kg/m(2) higher BMI was associated with a 0.06 kg/week lower GWG in the second trimester (p=0.005), but with a 0.05 higher GWG in the third trimester (p=0.03). Maternal BMI (p=0.014) and total GWG (p=0.05) correlated with birth weight., Conclusions: High BMI and low pre-pregnancy PAL were associated with excessive GWG. BMI and GWG, but not pre-pregnancy PAL, were linked to birth weight. However, together with smoking, parity, education and age, pre-pregnancy PAL and BMI explained only 4% of the variation in GWG. Thus, identification of other factors that could explain excessive GWG is an important area of future research.

Objective: The etiology of Wegener's granulomatosis (WG) supposedly involves interplay between genetic susceptibility and environmental triggers. However, little is known about whether WG actually clusters in families. Information on the degree of familial aggregation in WG is of clinical relevance, because patients with WG often want to know whether their diagnosis puts their closest relatives at increased risk of the disease. The aim of this study was to investigate the risk of WG in relatives of patients with WG., Methods: Using Swedish nationwide registers on morbidity, family structure, and vital status, we compared the occurrence of WG (register-based plus chart review) among 6,670 first-degree relatives and 428 spouses of 1,944 Swedish patients with WG with the occurrence among 68,994 first-degree relatives and 4,812 spouses of 19,655 control subjects from the general population. Relative risks were estimated using the Cox proportional hazards regression model., Results: Two of the 6,670 first-degree relatives of patients with WG and 13 of the 68,994 first-degree relatives of their population controls had WG, resulting in a relative risk of 1.56 (95% confidence interval 0.35-6.90). None of the 428 spouses of patients had WG., Conclusion: In absolute terms, the occurrence of WG among close biologic and nonbiologic relatives of patients with WG is low. In terms of relative risk, our results provide strong evidence against a pronounced increase in familial risk such as that noted for systemic lupus erythematosus, irritable bowel disease, and multiple sclerosis but are compatible with familial aggregation of a magnitude similar to that for rheumatoid arthritis.

We investigated whether dietary intakes of total fat, monounsaturated fat (MUFA), polyunsaturated fat (PUFA) and saturated fat (SFA) were associated with breast cancer risk in a prospective cohort of 49 261 Swedish women (30-49 years at enrolment), which yielded 974 breast cancer cases by December 2005. Further, we evaluated if associations differed by oestrogen and/or progesterone receptor tumour status. Total fat, MUFA, PUFA or SFA were not associated with risk overall. However, women in the highest MUFA and PUFA quintile intake had a reduced breast cancer risk after age 50 years (hazard ratios: 95% confidence interval=0.45: 0.25-0.99 and 0.54: 0.35-0.85, respectively) compared to women in the lowest quintile. The associations did not differ by oestrogen or progesterone receptor status. Despite the negative findings, type of fat during premenopausal years may have later differential effects on risk.

Background: Organized Papanicolaou (Pap) screening has markedly reduced the incidence of cervical squamous cell carcinoma (SCC). However, the potential for overtreatment of precursor lesions is quite high for SCC, and the effectiveness of Pap screening for prevention of cervical adenocarcinoma is questionable., Methods: Using the nationwide, virtually complete Swedish Cancer Register, we analyzed standardized incidence rates for SCC in situ (CIS), SCC, adenocarcinoma in situ (AIS) and adenocarcinoma, between 1968 and 2002. For each county, we calculated Spearman correlations between incidence of in situ lesions and incidence of invasive cancer, 5, 10, and 15 years later. We also used generalized estimating equation (GEE) models to compare adjusted estimates for associations between in situ incidences and invasive carcinomas over counties., Results: The overall decrease in SCC incidence in Sweden following the introduction of cervical screening confirms the beneficial nature of cervical screening on SCC incidence over the last 30 years. A similar benefit was not apparent for adenocarcinoma. GEE estimates for the relative change in SCC for an increase of 100 CIS cases per 100,000 women-years were 1.05 for the 5-year and 1.02 for the 10-year lag periods. For adenocarcinoma and AIS, similar analyses gave corresponding estimates of 1.17 for the 5-year and 1.08 for the 10-year lag periods. The lack of an inverse correlation suggests that increased reported incidence of CIS in certain counties did not forecast a reduction in SCC for those counties., Conclusion: Our data confirm the effectiveness of Pap smear screening in reducing the incidence of SCC, but suggest no clear benefit on adenocarcinoma. Our data also suggest that relaxed histopathologic criteria for diagnosis of cervical CIS may increase its recorded incidence with no measurable benefit in the reduction of invasive cancer.

Objective: The long-term health consequences of diets used for weight control are not established. We have evaluated the association of the frequently recommended low carbohydrate diets - usually characterized by concomitant increase in protein intake - with long-term mortality., Design: The Women's Lifestyle and Health cohort study initiated in Sweden during 1991-1992, with a 12-year almost complete follow up., Setting: The Uppsala Health Care Region., Subjects: 42,237 women, 30-49 years old at baseline, volunteers from a random sample, who completed an extensive questionnaire and were traced through linkages to national registries until 2003., Main Outcome Measures: We evaluated the association of mortality with: decreasing carbohydrate intake (in deciles); increasing protein intake (in deciles) and an additive combination of these variables (low carbohydrate-high protein score from 2 to 20), in Cox models controlling for energy intake, saturated fat intake and several nondietary covariates., Results: Decreasing carbohydrate or increasing protein intake by one decile were associated with increase in total mortality by 6% (95% CI: 0-12%) and 2% (95% CI: -1 to 5%), respectively. For cardiovascular mortality, amongst women 40-49 years old at enrolment, the corresponding increases were, respectively, 13% (95% CI: -4 to 32%) and 16% (95% CI: 5-29%), with the additive score being even more predictive., Conclusions: A diet characterized by low carbohydrate and high protein intake was associated with increased total and particularly cardiovascular mortality amongst women. Vigilance with respect to long-term adherence to such weight control regimes is advisable.

We explored the fertility in three generations; fertility of parents, siblings and offspring to patients with schizophrenia, to test the hypothesis that the decreased reproductive rate in the patients is compensated by an increased rate in their first-degree relatives. A population-based national database was created by linking the Swedish Multi-Generation and Hospital Discharge Registers. To maximize follow-up time for schizophrenia and reproductive history, three birth cohorts were selected: parental generation, born 1918-1927 (n=274464); affected generation, born 1932-1941 (n=108502) and offspring to affected generation, born 1951-1960 (n=103105). Ratios of estimated mean number of offspring were measured (fertility ratios), comparing the study subjects to the general population. The fertility among males with schizophrenia was decreased by over 70% (fertility ratio(patients/population)=0.29, 95% CI 0.25-0.35), whereas female patients had less than half as many offspring as the general female population (fertility ratio(patients/population)=0.48, 95% CI 0.42-0.55). When accounting for selection bias of larger families, no statistically significant difference was found among parents of patients with and without a diagnosis of schizophrenia. Further, the fertility among siblings of schizophrenic patients did not differ from the general population. A reduction in fertility was found among offspring to patients with schizophrenia, male offspring had 12% fewer offspring (fertility ratio(offspring/population)=0.88, 95%CI 0.77-1.01), while female offspring had 6% fewer offspring (fertility ratio(offspring/population)=0.94, 95% CI 0.84-1.05). In conclusion, we found reduced fertility in patients with schizophrenia and among their offspring that was not compensated by higher parental or sibling fertility.

An examination of birth weight in a Swedish cohort study of 38,566 women showed no significant association between birth weight and endometrial cancer, but supported a protective role for low birth weight for premenopausal breast cancer.

Studies of diet and health focus increasingly on dietary patterns. Although the traditional Mediterranean diet is perceived as being healthy, there is little information on its possible benefit to young people. We studied whether closer adherence to the traditional Mediterranean dietary pattern was associated with overall and cancer mortality in a cohort of 42,237 young women, aged 30-49 years at enrollment, who were recruited in 1991-2 from the general population in the Uppsala Health Care Region, Sweden, and followed up, almost completely, for about 12 years. Adherence to the Mediterranean diet was assessed by a 10-point score incorporating the characteristics of this diet. Among women less than 40 years old at enrollment--whose causes of death are mainly cancer with probable genetic influences, injuries or suicide--there was no association of the Mediterranean diet score with total or cancer mortality. Among women 40-49 years old at enrollment, a 2-point increase in the score was associated with considerable reductions in overall mortality (13%; 95% CI 1%, 23%; P approximately 0.05) and cancer mortality (16%; 95% CI -1%, 29%; P approximately 0.06). Few cardiovascular deaths occurred in this cohort of young women. The findings of the present study in a northern European population of young women indicate that closer adherence to a Mediterranean dietary pattern reduces mortality even among young persons.

Background: Reports during the early 1990s indicated non-Hodgkin's lymphoma (NHL) as one of the most rapidly increasing malignancies. More recent trends remain poorly characterized, as do the underlying reasons for NHL time trends, in particular, the effect of changes in classification and registration of lymphoproliferative malignancies. Insights into the descriptive epidemiology of NHL may shed light upon its elusive etiology., Methods: We used data from the Swedish, Danish, and Finnish national cancer registers to assess the incidences of NHL and other lymphoproliferative malignancies between 1960 and 2004. Using Poisson regression, we estimated the annual rate of change in NHL incidence per decade by sex, age, and country., Results: In Sweden, Denmark, and Finland, the NHL incidence increased in both genders and all age categories by about 4% every year up until the early 1990s. Thereafter, the incidence increased at a slower rate (ages 60-79 years), stabilized (ages 50-59 and > or =80 years), and decreased (ages 0-49 years), respectively, similarly for males and females in the three countries. Time trends of NHL were not reciprocated and explained by trends for other lymphoproliferative malignancies nor explained by trends in NHL as secondary primaries or NHL diagnosed postmortem., Conclusions: The epidemic increase of NHL has recently subsided. Changes in the classification of lymphoproliferative malignancies, or occurrence of NHL as second primaries, only offer a marginal explanation.

Only few studies have assessed the role of physical activity in the etiology of ovarian cancer, and the results have been inconclusive. We studied associations between physical activity and risk of ovarian cancer in 96,541 women aged 30-49 at enrollment in a prospective study in Norway and Sweden. Participants reported physical activity level at ages 14, 30 and at enrollment, and participation in competitive sports. Complete follow-up through 2001/2002 was achieved by linkage to national registries. The relation between physical activity and ovarian cancer incidence was assessed using multivariate Cox proportional hazard models. During an average 11.1 years of follow-up, there were 264 ovarian cancer cases (including 81 borderline tumors) diagnosed at a mean age of 49 years. Highly physically active women at cohort enrollment had a similar risk of ovarian cancer as women reporting no activity (multivariate relative risk RR = 1.08, 95% CI 0.53-2.18). Physical activity at age 30 or at age 14 did not either afford any protection from ovarian cancer, nor did a consistently high level of activity from younger ages until enrollment. Results were similar for invasive and borderline tumors, and for different subgroups of women classified according to other known risk factors for ovarian cancer. In our study of primarily premenopausal women, physical activity at different ages did neither reduce nor increase risk of ovarian cancer. In the context of the inconsistent scientific literature, our findings probably reflect that physical activity is not causally related with ovarian cancer., (Copyright 2006 Wiley-Liss, Inc.)

The polypeptide growth factor, hepatocyte growth factor/scatter factor (HGF/SF), shares the multidomain structure and proteolytic mechanism of activation of plasminogen and other complex serine proteinases. HGF/SF, however, has no enzymatic activity. Instead, it controls the growth, morphogenesis, or migration of epithelial, endothelial, and muscle progenitor cells through the receptor tyrosine kinase MET. Using small-angle x-ray scattering and cryo-electron microscopy, we show that conversion of pro(single-chain)HGF/SF into the active two-chain form is associated with a major structural transition from a compact, closed conformation to an elongated, open one. We also report the structure of a complex between two-chain HGF/SF and the MET ectodomain (MET928) with 1:1 stoichiometry in which the N-terminal and first kringle domain of HGF/SF contact the face of the seven-blade beta-propeller domain of MET harboring the loops connecting the beta-strands b-c and d-a, whereas the C-terminal serine proteinase homology domain binds the opposite "b" face. Finally, we describe a complex with 2:2 stoichiometry between two-chain HGF/SF and a truncated form of the MET ectodomain (MET567), which is assembled around the dimerization interface seen in the crystal structure of the NK1 fragment of HGF/SF and displays the features of a functional, signaling unit. The study shows how the proteolytic mechanism of activation of the complex proteinases has been adapted to cell signaling in vertebrate organisms, offers a description of monomeric and dimeric ligand-receptor complexes, and provides a foundation to the structural basis of HGF/SF-MET signaling.

The aim of this study was to investigate what psychosocial predictors, life-style factors and health behaviors in early adulthood are of importance for self-ratings of health after the age of 45. Like-sexed adult twins born 1926-1950 (n = 16,080) from the Swedish Twin Registry that participated in a questionnaire in 1973 and in a telephone interview conducted between 1998 and 2002 were included. Exposure data was collected in 1973 and information on self-rated health and covariates was collected at the second contact 25 years later. Logistic regression using Generalized Estimating Equations was used to evaluate the associations. Conditional logistic regression was used to control for familial and genetic effects in the sample. Pain, lack of exercise, smoking, obesity, unemployment, perceived stress and personality are associated with future poor self-rated health, after controlling for age, sex, illness, education and socio-economic status. Familial and genetic effects influence the associations between recurrent headache, exercise, obesity, and poor self-rated health. Overall, these findings provide support for long-term effects of health behavior and psychosocial risk factors on poor self-ratings of health, beyond the influence of obvious health consequences such as disorders or illnesses. Genetic and familial factors are of importance only for some of these associations.

Background: There is substantial evidence that higher levels of activity reduce the risk of mortality, but several research questions remain about the protective effect of physical activity. We aimed to quantify the effect of physical activity on overall mortality in younger women and to assess the effect of past versus current activity., Methods: During 1991-1992, we enrolled 99,099 women, age 30-49 years, from the entire country of Norway and one Swedish region, in a population-based cohort study. The women provided information on physical activity level at age 14 and 30 years and at enrollment, as well as information on other personal characteristics at enrollment. We achieved complete follow-up into 2003 using record linkages to nationwide registers. We used Cox proportional hazard models to calculate multivariate relative risks (RRs) of dying from any cause., Results: During an average 11.4 years of follow-up, 1,313 women died. Risk of death decreased with increasing physical activity at enrollment (5 categories; P for trend<0.0001) and was reduced by half in the highest compared with the lowest category (RR=0.46; 95% confidence intervals=0.33-0.65). This protective effect was consistent across strata of age at entry, smoking, country, and education. After adjustment for physical activity at enrollment, activity at age 14 and 30 was not associated with mortality., Conclusions: Current physical activity substantially reduces mortality among women. This association is observed even with low levels of physical activity and is accentuated with increased physical activity.

Objectives: This study first considers age and cohort explanations for age-related changes in mean values and variance in self-rated health. Second, it evaluates the contributions of genes and environments to self-rated health measured longitudinally., Methods: Subjects were participants in the Swedish Adoption/Twin Study of Aging. Self-rated health assessments were collected in four waves over a 9-year follow-up period, from one or both members of 788 twin pairs. Linear mixed effect models were used to test for differences in means and variances. Structural equation modeling provided estimates of genetic and environmental components of variance and contributions to stability., Results: Changes in means and variance within cohorts seem to reflect illness. Earlier-born cohorts are more variable and have lower self-rated health. These cohort differences were not explained by childhood socioeconomic status. Correlations between time points reflect both environmental and genetic factors., Discussion: Both genes and environments contribute to self-rated health longitudinally, and both age and cohort effects are seen. Age-related changes in self-rated health can be attributed to illness. Cohort differences are most likely attributable to socially mediated and individual-specific environmental factors.

The issue of protein dynamics and its implications in the biological function of proteins are arousing greater and greater interest in molecular biology. In cryo-electron tomography experiments one takes several snapshots of a given biological macromolecule. In principle, a large enough collection of snapshots may then be used to calculate its equilibrium configuration in terms of the experimentally accessible degrees of freedom, and hence estimate its potential energy. Consequently, one could analyze the biological functions of biomolecules by directly accessing their dynamics. In this work, we analyze the results of cryo-electron tomography experiments on monoclonal murine IgG2a antibodies. With the aid of a novel software for image processing, we measure the equilibrium distribution of the angles which describe the configuration of the molecule. This helps us shed some critical light on recent results from X-ray crystallography. We then build a model of the antibody dynamics, which enables us to use the measured angular distribution in order to derive an explicit expression of the IgG potential energy. Finally, as a preliminary application of our results, we investigate the dynamical effects in the rate of formation of the antigen-antibody encounter complex. In particular, we suggest that the dynamics of antibodies operates in the direction of decreasing anticooperativity of the two antigen binding arms.

Nephrin is a key functional component of the slit diaphragm, the structurally unresolved molecular filter in renal glomerular capillaries. Abnormal nephrin or its absence results in severe proteinuria and loss of the slit diaphragm. The diaphragm is a thin extracellular membrane spanning the approximately 40-nm-wide filtration slit between podocyte foot processes covering the capillary surface. Using electron tomography, we show that the slit diaphragm comprises a network of winding molecular strands with pores the same size as or smaller than albumin molecules, as demonstrated in humans, rats, and mice. In the network, which is occasionally stratified, immunogold-nephrin antibodies labeled individually detectable globular cross strands, about 35 nm in length, lining the lateral elongated pores. The cross strands, emanating from both sides of the slit, contacted at the slit center but had free distal endings. Shorter strands associated with the cross strands were observed at their base. Immunolabeling of recombinant nephrin molecules on transfected cells and in vitrified solution corroborated the findings in kidney. Nephrin-deficient proteinuric patients with Finnish-type congenital nephrosis and nephrin-knockout mice had only narrow filtration slits that lacked the slit diaphragm network and the 35-nm-long strands but contained shorter molecular structures. The results suggest the direct involvement of nephrin molecules in constituting the macromolecule-retaining slit diaphragm and its pores.

Background: The new local anesthetic IQB-9302 is an amide derivative bearing a cyclopropyl group, with remarkable long duration of action and relative low toxicity. In trying to characterize further its safety profile, the current study compared the hemodynamic effects of different concentrations of bupivacaine and IQB-9302 with saline., Methods: Two groups of eight anesthetized Sprague-Dawley rats were given 0.1, 0.3, 1, 3, and 10 mg/kg of intravenous (i.v.) IQB-9302 or bupivacaine at 20-min intervals; control animals received saline only. Arterial blood pressure and heart rate were monitored during the following 20 min., Results: Both bupivacaine and IQB-9302 reduced heart rate: for bupivacaine, -73.8 beats per min (bpm) (SD: 103.8) and -132.5 bpm (SD: 140.7) at 1 and 3 mg/kg, respectively; for IQB-9302, the reduction amounted to -40.8 bpm (SD: 14.2) and -113.5 bpm (SD: 94.2) at 1 and 3 mg/kg, respectively (baseline range, 318.7-438.2 bpm). The two drugs also produced a comparable increase in the mean arterial blood pressure; bupivacaine increased it by 8.7 mmHg (SD: 6.6) and 12.6 mmHg (SD: 15.4) at 1 and 3 mg/kg, respectively, and IQB-9302, 18.7 mmHg (SD: 21.1) and 20.7 mmHg (SD: 20.5) at 1 and 3 mg/kg, respectively (baseline range, 47.4-134.1 mmHg). All rats treated with 10 mg/kg of either drug died after a drop in heart rate and mean arterial blood pressure., Conclusion: IQB-9302 had hemodynamic effects similar to those of bupivacaine in anesthetized rats. The clinical relevance of these effects warrants further investigation.

The issue of protein dynamics and its implications in the biological function of proteins are arousing greater and greater interest in different fields of molecular biology. In cryo-electron tomography experiments one may take several snapshots of a given biological macromolecule. In principle, a large enough collection of snapshots of the molecule may then be used to calculate its equilibrium configuration in terms of the experimentally accessible degrees of freedom and, hence, to estimate its potential energy. This information would be crucial in order to analyze the biological functions of biomolecules by directly accessing the relevant dynamical indicators. In this article, we analyze the results of cryo-electron tomography experiments performed on monoclonal murine IgG2a antibodies. We measure the equilibrium distribution of the molecule in terms of the relevant angular coordinates and build a mechanical model of the antibody dynamics. This approach enables us to derive an explicit expression of the IgG potential energy. Furthermore, we discuss the configuration space at equilibrium in relation to results from other techniques, and we set our discussion in the context of the current debate regarding conformation and flexibility of antibodies.

In contrast to averaging methods of determining structure, such as X-ray diffraction, NMR, and single-particle tomography, cryo-electron tomography allows three-dimensional imaging of an individual object in solution. The method has previously been used to study cells and very large macromolecules. We have used cryo-electron tomography to analyze a monoclonal IgG, with a molecular weight of only 150 kDa. Tomograms reveal y-shaped IgG molecules with three protruding subunits. Docking X-ray structures enabled us to recognize the three subunits as two ellipsoidal Fab arms and a heart-shaped Fc stem. Each subunit has a similar structure in the tomograms and in the X-ray map. Notably, the positions of the Fab arms relative to the Fc stem differed greatly from one molecule to another. The large flexibility of IgG in solution is most likely of functional significance in antigen recognition. This distribution of individual structures provides a qualitative insight into the system dynamics.

Human immunodeficiency type 1 (HIV-1) bearing the nucleocapsid (NC) mutation R10A/K11A is replication defective. After serial passage of the mutant virus in tissue culture, we isolated a revertant that retained the original mutation. It had acquired, in addition, a new mutation (E21K) that was formally demonstrated to be sufficient for restoration of viral replication. Detailed analysis of the replication defect of R10A/K11A revealed a threefold reduction in virion yield and a fivefold reduction in packaging of viral genomic RNA. Real-time PCR was then used to quantitate viral DNA synthesis following infection of Jurkat T cells. After adjustment for the assembly and packaging defects, a minor (twofold) reduction in synthesis of either strong-stop, full-length linear DNA or 2-LTR circles was observed with R10A/K11A virions, indicating that reverse transcription and nuclear transport of the viral genome were largely intact. However, after adjustment for the amounts of full-length or 2-LTR circles produced, R10A/K11A virions were at least 10-fold less infectious than wild type, indicating that viral DNA produced by the R10A/K11A mutant failed to integrate. Each of the above-mentioned defects was corrected by introduction of the second-site compensatory mutation E21K. These results demonstrate that the replication defect of mutant R10A/K11A can be explained by impairment at multiple steps in the viral life cycle, most important among them being integration and RNA packaging. The E21K mutation is predicted to restore positive charge to the face of the R10A/K11A mutant NC protein that interacts with the HIV-1 SL3 RNA stem-loop, emphasizing the importance of NC basic residues for HIV-1 replication.

Retroviral Gag polyproteins drive virion assembly by polymerizing to form a spherical shell that lines the inner membrane of nascent virions. Deletion of the nucleocapsid (NC) domain of the Gag polyprotein disrupts assembly, presumably because NC is required for polymerization. Human immunodeficiency virus type 1 NC possesses two zinc finger motifs that are required for specific recognition and packaging of viral genomic RNA. Though essential, zinc fingers and genomic RNA are not required for virion assembly. NC promiscuously associates with cellular RNAs, many of which are incorporated into virions. It has been hypothesized that Gag polymerization and virion assembly are promoted by nonspecific interaction of NC with RNA. Consistent with this model, we found an inverse relationship between the number of NC basic residues replaced with alanine and NC's nonspecific RNA-binding activity, Gag's ability to polymerize in vitro and in vivo, and Gag's capacity to assemble virions. In contrast, mutation of NC's zinc fingers had only minor effects on these properties.

The three amino acids glycine, proline, and glycine (GPG) constitute a conserved motif at the center of the V3 loop of HIV-1 surface glycoprotein 120. It has been indicated that deletion of this GPG motif is lethal for viral infectivity and abrogates the ability of the virus to form syncytia. In the present work, we studied the effects of GPG deletion on viral infectivity, cell tropism, syncytium formation, and initiation of apoptosis by constructing a mutant provirus based on the infectious clone pBRu-2. Successful infection and replication of GPG-deleted virus were detected in MT-2 cells, although the mutant virus showed lower infectivity. Infection could also be observed in the C8166, C91-PL, Molt-3, and THP-1 cell lines, and in PBMC-derived dendritic cells (DCs), but not in CEM-SS, HUT78, H9, Jurkat, and U937 cell lines or in PBMCs. Mutant virus also induced syncytia and apoptosis in the MT-2 cells. An intact GPG motif is probably necessary for unimpaired induction of fusion in some HIV-1-permissive cells. However, once the virus enters the cells, the GPG sequence does not seem to be indispensable for syncytium formation or apoptosis induction in MT-2 cells. Our data also imply that cell surface molecules other than CD4 and CXCR4 may be involved in entry of the GPG-deleted virus.

To predict the risk of adverse reactions to local anaesthetics used in clinical practice, it is crucial to know whether any nonlinearity exists in their pharmacokinetics. The disposition of ropivacaine, a new local anesthetic agent, was evaluated in healthy subjects on the basis of plasma levels in the concentration range obtained after regional anaesthesia. Three intravenous doses of ropivacaine hydrochloride (20, 40, and 80 mg) were given in a double-blind, randomized, complete crossover design. Analysis of variance was used to assess the importance of intra- versus interindividual variability in the basic pharmacokinetics. The mean plasma clearance (400 ml/min), volume of distribution at steady state (40 l), and terminal half-life (1.7 h) were similar, irrespective of dose. The intersubject variability for these parameters was higher than the intrasubject variability. A slight increase in free fraction (15%) with increasing dose might indicate that the lower limit for saturation of protein binding may be reached at the higher plasma levels. One subject (80 mg) reported numbness of the lower lip 2 min after the end of the infusion, which may be a sign of systemic CNS toxicity. The total and free plasma concentration was extrapolated to 1.7 and 0.08 mg/l, respectively.