Hypercholesterolaemia, signs of islet microangiopathy and altered angiogenesis precede onset of type 2 diabetes in the Goto-Kakizaki (GK) rat.

AIMS/HYPOTHESIS: The adult non-obese Goto-Kakizaki (GK) rat model of type 2 diabetes, particularly females, carries in addition to hyperglycaemia a genetic predisposition towards dyslipidaemia, including hypercholesterolaemia. As cholesterol-induced atherosclerosis may be programmed in utero, we looked for signs of perinatal lipid alterations and islet microangiopathy. We hypothesise that such alterations contribute towards defective pancreas/islet vascularisation that might, in turn, lead to decreased beta cell mass. Accordingly, we also evaluated islet inflammation and endothelial activation in both prediabetic and diabetic animals. METHODS: Blood, liver and pancreas were collected from embryonic day (E)21 fetuses, 7-day-old prediabetic neonates and 2.5-month-old diabetic GK rats and Wistar controls for analysis/quantification of: (1) systemic variables, particularly lipids; (2) cholesterol-linked hepatic enzyme mRNA expression and/or activity; (3) pancreas (fetuses) or collagenase-isolated islet (neonates/adults) gene expression using Oligo GEArray microarrays targeted at rat endothelium, cardiovascular disease biomarkers and angiogenesis, and/or RT-PCR; and (4) pancreas endothelial immunochemistry: nestin (fetuses) or von Willebrand factor (neonates). RESULTS: Systemic and hepatic cholesterol anomalies already exist in GK fetuses and neonates. Hyperglycaemic GK fetuses exhibit a similar percentage decrease in total pancreas and islet vascularisation and beta cell mass. Normoglycaemic GK neonates show systemic inflammation, signs of islet pre-microangiopathy, disturbed angiogenesis, collapsed vascularisation and altered pancreas development. Concomitantly, GK neonates exhibit elevated defence mechanisms. CONCLUSIONS/INTERPRETATION: These data suggest an autoinflammatory disease, triggered by in utero programming of cholesterol-induced islet microangiopathy interacting with chronic hyperglycaemia in GK rats. During the perinatal period, GK rats show also a marked deficient islet vascularisation in conjunction with decreased beta cell mass.

IL-1 antagonism reduces hyperglycemia and tissue inflammation in the type 2 diabetic GK rat.

Recent studies suggest an inflammatory process, characterized by local cytokine/chemokine production and immune cell infiltration, regulates islet dysfunction and insulin resistance in type 2 diabetes. However, the factor initiating this inflammatory response is not known. Here, we characterized tissue inflammation in the type 2 diabetic GK rat with a focus on the pancreatic islet and investigated a role for IL-1. GK rat islets, previously characterized by increased macrophage infiltration, displayed increased expression of several inflammatory markers including IL-1beta. In the periphery, increased expression of IL-1beta was observed primarily in the liver. Specific blockade of IL-1 activity by the IL-1 receptor antagonist (IL-1Ra) reduced the release of inflammatory cytokines/chemokines from GK islets in vitro and from mouse islets exposed to metabolic stress. Islets from mice deficient in IL-1beta or MyD88 challenged with glucose and palmitate in vitro also produced significantly less IL-6 and chemokines. In vivo, treatment of GK rats with IL-1Ra decreased hyperglycemia, reduced the proinsulin/insulin ratio, and improved insulin sensitivity. In addition, islet-derived proinflammatory cytokines/chemokines (IL-1beta, IL-6, TNFalpha, KC, MCP-1, and MIP-1alpha) and islet CD68(+), MHC II(+), and CD53(+) immune cell infiltration were reduced by IL-1Ra treatment. Treated GK rats also exhibited fewer markers of inflammation in the liver. We conclude that elevated islet IL-1beta activity in the GK rat promotes cytokine and chemokine expression, leading to the recruitment of innate immune cells. Rather than being directly cytotoxic, IL-1beta may drive tissue inflammation that impacts on both beta cell functional mass and insulin sensitivity in type 2 diabetes.

Prominently decreased hippocampal neurogenesis in a spontaneous model of type 1 diabetes, the nonobese diabetic mouse.

In human diabetes, degenerative and functional disorders of the central nervous system, including depression, are common findings. Defective dentate gyrus (DG) neurogenesis is associated with affective-related disorders and depression. We previously demonstrated reduced DG neurogenesis in a pharmacological type 1 diabetes model, the streptozotocin (STZ)-treated mouse. Here, we explored DG neurogenesis in a spontaneous T1D model, the nonobese diabetic (NOD) mouse, at prediabetic and diabetic stages. Cell proliferation was assessed in the DG of 5, 8 and 12-week-old control C57BL/6 and BALB/c strains and NOD mice, killed 2 h after bromodeoxyuridine (BrdU) administration. Survival of the newly generated cells was studied in 15-week-old animals that were killed 21 days after BrdU injection. The number of proliferative BrdU-positive cells in the DG was, regardless of age, constantly and significantly lower in NOD than in control strains, showing the presence of hippocampal alterations far before clinical diabetes onset in NOD mice. Diabetes also strongly decreased cell survival in NOD DG. However, cell phenotype proportion, as assessed by co-localization with neuronal or glial markers and confocal microscopy, was not modified. Hippocampal neurogenesis is strongly diminished in the spontaneous NOD model, like in the STZ model. Notably, NOD hippocampal DG cell proliferation defect takes place during the prediabetic stage. Whether this early alteration might result, in this autoimmune strain, from hypothalamo-pituitary adrenal axis alterations and/or ongoing brain inflammatory process sharing many characteristics of aging is discussed and deserves further investigation.

Marked genetic differences in the regulation of blood glucose under immune and restraint stress in mice reveals a wide range of corticosensitivity.

Male and female mice from different control strains (C57BL/6, DBA/2, BALB/c) and the nonobese diabetic (NOD) strain, a spontaneous model of type 1 diabetes, were subjected to various stressors (restraint, lipopolysaccharide or interleukin-1 injection). Significant differences were measured among strains in blood glucose, insulin and corticosterone levels and, for restraint, IL-6. Addition of dexamethasone, a glucocorticoid receptor agonist, to inhibit the expression of several proteins by LPS-stimulated bone marrow-derived macrophages in vitro showed a gradient among control strains: C57BL/6>DBA/2>BALB/c corroborating the pattern of corticosensitivity suggested by their stress-induced glucose responses at the systemic level.

Age as a risk factor for severe manifestations and fatal outcome of falciparum malaria in European patients: observations from TropNetEurop and SIMPID Surveillance Data.

Previous studies have indicated that age is a risk factor for severe falciparum malaria in nonimmune patients. The objectives of this study were to reevaluate previous findings with a larger sample and to find out how strongly clinical outcomes for elderly patients differ from those for younger patients. Results of adjusted analyses indicated that the risks of death due to falciparum malaria, of experiencing cerebral or severe disease in general, and of hospitalization increased significantly with each decade of life. The case-fatality rate was almost 6 times greater among elderly patients than among younger patients, and cerebral complications occurred 3 times more often among elderly patients. Antimalarial chemoprophylaxis was significantly associated with a lower case-fatality rate and a lower frequency of cerebral complications. Women were more susceptible to cerebral complications than were men. Our study provides evidence that falciparum malaria is more serious in older patients and demonstrates that clinical surveillance networks are capable of providing quality data for investigation of rare events or diseases.

A simple clinical and paraclinical score predictive of CD4 cells counts below 400/mm3 in HIV-infected adults in Dakar University Hospital, Senegal.

In industrialized countries the decision to start co-trimoxazole (CMX) prophylaxis of HIV-related opportunistic infections is based on the CD4+ cell count. The value of CMX prophylaxis has also been demonstrated in Africa, where CD4+ cell counts are rarely available. We therefore developed a simple score predictive of a threshold CD4+ cell count (400/mm3) below which CMX prophylaxis is indicated. In a retrospective cross-sectional study, we collected clinical and biological data on 211 HIV-infected patients recruited from January 1996 through January 1998 at Fann University Hospital in Dakar, Senegal. Several variables were identified as being predictive of a CD4+ cell count below 400/mm3 by stepwise logistic regression. Each variable was weighted according to its regression coefficient, as follows: male sex (+1), weight loss (+2), body mass index < 22 (+2), herpes zoster (+4), tuberculin induration < 5 mm (+3) and haemoglobin < or = 10 g/dL (+1). A score of > or = 4 (sum of weights) selected patients with CD4+ cell counts below 400/mm3 with a sensitivity of 98% and a negative predictive value of 83%. Such a score should be applicable in the African context and should facilitate the management of HIV-infected patients, especially the prescription of CMX prophylaxis.

Imported Falciparum malaria in Europe: sentinel surveillance data from the European network on surveillance of imported infectious diseases.

Malaria continues to have a high morbidity rate associated among European travelers. Thorough recording of epidemiological and clinical aspects of imported malaria has been helpful in the detection of new outbreaks and areas of developing drug resistance. Sentinel surveillance of data collected prospectively since 1999 has begun within TropNetEurop, a European network focusing on imported infectious diseases. TropNetEurop appears to cover approximately 10% of all patients with malaria seen in Europe. Reports of 1659 immigrants and European patients with Plasmodium falciparum malaria were analyzed for epidemiological information and data on clinical features. Regional data were quite diverse, reflecting local patterns of immigration and international travel. By far, the most infections were imported from West Africa. Europeans had more clinical complications; consequently, all deaths occurred in this group. Compared with European standards, the mortality rate was low (0.6% in Europeans). Data from TropNetEurop member sites can contribute to our understanding of the epidemiological and clinical findings regarding imported falciparum malaria.

Nuclear DNA content, base composition, heterochromatin and rDNA in Picea omorika and Picea abies.

Two closely related spruces, Picea abies and Picea omorika, a Balkan paleoendemic species, often share habitats, yet never hybridize in nature. The present study adresses their characteristics such as nuclear DNA content, base composition, heterochromatin and rDNA pattern. The genome size of P. abies was 10% larger than that of P. omorika when assessed by flow cytometry, respectively 2C=37.2 pg and 33.8 pg; although when estimated as total chromosome length it was virtually the same. The heterochromatin Chromomycin-A (CMA)/ DAPI fluorochrome banding patterns of both P. abies and P. omorikaare given here for the first time. Simultaneous FISH (fluorescent in situ hybridization) using 18S-26S and 5S rDNA probes revealed 16 18S rDNA sites in P. omorika, 12 18S rDNA sites in P. abies, and a single 5S rDNA locus in both species. The genomes have about 41% GC. The number and position of CMA/DAPI bands and rDNA loci provide good chromosome markers to clarify the karyotypes of the two species.

Islet endocrine-cell behavior from birth onward in mice with the nonobese diabetic genetic background.

BACKGROUND: Glucagon-producing alpha cells play a crucial role during the perinatal period. Because of their peri-islet localization near the early dendritic and macrophage cell infiltration, we thought it pertinent to investigate alpha cells in greater depth in nonobese diabetic (NOD) mice, a well-recognized spontaneous model for human type I diabetes. MATERIALS AND METHODS: We determined alpha-cell distribution (glucagon immunohistochemistry and image analysis) and activity (real-time reverse transcriptase polymerase chain reaction [RT-PCR] and glucagon radioimmunoassay [RIA]), in relationship to glycemia in NOD and lymphocyte-deficient NODscid mice as compared to control mice (C57BL/6) from birth onward. RESULTS: NOD and NODscid mice, particularly at 1 day of age, had twice as many very small islets (<2,000 pixels) as C57BL/6 mice. During the postnatal period, the percentages of glucagon-positive areas in islets less than 2000 pixels were higher in NOD mice than C57BL/6; only a trend was found in NODscid. Pancreatic mRNA expression and glucagon content decreased in all strains at weaning. However, before weaning, pancreatic and blood glucagon levels were significantly lower in NOD and NODscid compared to C57BL/6 mice. Low basal nonfasting glycemia was observed in all strains before weaning with some strain differences: glycemia was significantly lower in NOD than C57BL/6, and higher in NODscid than NOD and C57BL/6. CONCLUSION: These data suggest that, before weaning, NOD and, to some extent NODscid pancreata contain more immature islets (as reflected by their small size and high percentages of glucagon-positive areas, concomitant with lower glucagon storage and basal secretion) than C57BL/6 pancreata.

Comparison of two methods to obtain a desired first isepamicin peak in intensive care patients.

A randomized multicenter study in intensive care unit (ICU) patients, evaluated the capacity of a Bayesian method to obtain an optimal first isepamicin (ISP) peak of 80 mg/L in comparison to a fixed loading dose (LD). Patients (n=236) over 18 years of age were enrolled from 6 September 1997 to 17 July 1999 and randomly assigned to received ISP in a calculated dose (CD) or a loading dose (LD) of 25 mg/kg body weight. The CD was estimated using a specific population model with Bayesian methodology implemented in the PKS program (Abbott PKS, Abbott Diagnostics, Rungis, France). The data required included age, body weight, height, gender and serum creatinine. ISP disposition is described by a one-compartment model. Blood samples were drawn 1 and 24 h after the start of infusion for fluorescence polarization immunoassay measurement of serum ISP concentrations. The predictive performance was assessed by computing bias and precision. Peak concentrations were significantly higher in CD group than the LD group (84.2 +/- 28.6 vs. 74.7 +/- 24.1 mg/L, respectively; P=0.008), but trough levels were comparable. The optimal ISP peak was attained by a significantly higher percentage of CD patients (P=0.018), and by significantly more CD patients on mechanical ventilation (P=0.025), and with simplified acute physiological scores (SAPS) > 35 (P=0.002). Pharmacokinetic parameters were similar for the two groups with large interindividual variations. Mean (+/- SD) volume of distribution of ventilated patients (72%) was significantly higher than of nonventilated patients (23.31 +/- 7.35 vs. 20.60 +/- 6.30 L, respectively; P=0.001). No relationship was found between the volume of distribution and SAPS. Total clearance was significantly correlated with estimated CLCR (creatinine clearance) (P=0.0001). Precision (RMSE) is better for CD than for LD strategy, respectively 27.96 and 28.66 mg/L. The Bayesian method was significantly more accurate and performed particularly well in ventilated patients and patients with high SAPS, compare to an LD of 25 mg/kg to obtain a first ISP peak of 80 mg/L in ICU patients. Therefore, a fixed dose of 28.5 mg/kg would be also adequate to reach a peak of 80 mg/L.

Primary prevention with cotrimoxazole for HIV-1-infected adults: results of the pilot study in Dakar, Senegal.

OBJECTIVES: To assess the efficacy and tolerance of chemoprophylaxis with cotrimoxazole compared with placebo among HIV-1-infected adults. DESIGN: Randomized, double-blind, placebo-controlled clinical trial in the urban community of Dakar, Senegal. METHODS: Eligibility criteria were age greater than 15 years, HIV-1 or HIV-1 and HIV-2 dual seropositivity, CD4 cell count lower than 400 copies/mm3, no progressive infection, no previous history of intolerance to sulphonamide, lack of severe anemia or neutropenia, and renal or hepatic failure. Written informed consent was obtained. Recruited patients received 80 mg of trimethoprim and 400 mg of sulphamethoxazole daily or a matching placebo. The main outcomes were survival and the occurrence of clinical events defined as Pneumocystis carinii pneumonia, cerebral toxoplasmosis, bacterial pneumonia, infectious enteritis, bacterial meningitis, urinary tract infection, bacterial otitis and sinusitis, and pyomyositis. RESULTS: Between September 1996 and March 1998, 297 patients were screened, and 100 were randomized in the study. Demographic, clinical, and biological characteristics of the two groups were similar as was the mean length of follow-up (7.7 months for the cotrimoxazole group vs. 8.0 months for the placebo group). There was no significant difference between the two groups in survival (hazard ratio = 0.84; 95% confidence interval [CI]: 0.36-1.94) in the probability of severe event occurrence, defined as death or hospital admission (hazard ratio = 1.10; 95% CI: 0.57-2.13), or in the probability of clinical event occurrence (hazard ratio = 1.19; 95% CI: 0.55-2.59). Adjustment for initial CD4 cell count did not change these results. A low dose of cotrimoxazole was tolerated well clinically as well as biologically; only one treatment interruption occurred as the result of a moderate cutaneous eruption (grade 2). CONCLUSION: Our study does not show a beneficial effect of chemoprophylaxis with low-dose cotrimoxazole on survival or occurrence of opportunistic or nonopportunistic infections for HIV-1-infected patients in Dakar, Senegal.

Cutaneous larva migrans in travelers: a prospective study, with assessment of therapy with ivermectin.

The purpose of this prospective study was to update epidemiological data on cutaneous larva migrans (CLM) and to assess the therapeutic efficacy of ivermectin. We performed the study between June 1994 and December 1998 at our travel clinic. Ivermectin (a single dose of 200 microg/kg) was offered to all the patients with CLM, and its efficacy and tolerability were assessed by a questionnaire. Sixty-four patients were enrolled. All were European and had stayed in tropical areas. After the patients had returned from their destinations, 55% had lesions occur within a mean of 16 days (range, 1-120 days; >1 month in 7 patients). The initial diagnosis was wrong in 55% of patients. The mean number of lesions was 3 (range, 1-15), and the main sites were the feet (48%) and buttocks (23%). The cure rate after a single dose of ivermectin was 77%. In 14 patients, 1 or 2 supplementary doses were necessary, and the overall cure rate was 97%. The median time required for pruritus and lesions to disappear was 3 and 7 days, respectively. No systemic adverse effects were reported. Physicians' knowledge of CLM, which can have a long incubation period, is poor. Single-dose ivermectin therapy appears to be effective and well tolerated, even if several treatments are sometimes necessary.

Use of the Parasight-F diagnostic test for imported malaria in a travel clinic.

The Parasight-F test based on the detection of a soluble antigen specific for Plasmodium falciparum is designed for the immediate diagnosis of malaria infection. We evaluated its use by clinicians during consultations. This prospective study of its diagnostic utility in febrile patients consulting a travel clinic on their return from areas endemic for malaria was conducted between May 1996 and May 1997. The Parasight-F test was performed by the clinician with confirmation by means of standard microscopic examination of venous blood. One-hundred and forty patients were enrolled. Forty-three (31%) cases of malaria were identified by microscopic examination. Thirty-eight were due to P. falciparum. The Parasight-F tests yielded 6 false-positive and 3 false-negative results compared to the microscopic findings. The specificity and sensitivity for the diagnosis of P. falciparum malaria were 94% and 92%. These results show that the Parasight-F test alone cannot replace microscopic diagnosis of malaria in travel clinics.

Atovaquone plus proguanil versus halofantrine for the treatment of imported acute uncomplicated Plasmodium falciparum malaria in non-immune adults: a randomized comparative trial.

In endemic zones, the atovaquone-proguanil (AP) combination is well tolerated and effective in treating acute, uncomplicated malaria. Trials involving non-immune patients are lacking, however. We conducted a randomized, multicenter open-label trial to determine the efficacy and tolerability of the AP combination (1,000 mg + 400 mg once daily for 3 days) in comparison with halofantrine (HF) (1,500 mg in 3 doses) in non-immune adults with imported uncomplicated Plasmodium falciparum malaria. Follow-up visits were programmed on Days 7, 14, 21, 28, and 35 after hospital discharge. Out of 48 patients enrolled in the study, 41 were assessable for the cure rate (21 in the AP group and 20 in the HF group). All the patients were cured. The mean parasite clearance time was longer (63+/-23 hours) in the AP group than in the HF group (48+/-15 hours) (P = 0.02). The frequency of gastrointestinal adverse events was higher in the AP group. No noteworthy electrocardiographic changes were observed, particularly in the QTc interval. The AP combination appears to be a valuable alternative treatment in non-immune adults.

[Invasive aspergillosis sinusitis in patients infected by the human immunodeficiency virus]. / Sinusites aspergillaires invasives chez les patients infectés par le virus de l'immunodéficience humaine.

Invasive aspergillus sinusitis invasive is a rare, life threatening infection observed in immunocompromised patients. We report three cases of patients with AIDS. Diagnosis was based on surgical biopsy specimen performed on patients with unilateral sinusitis with facial pain and osteolysis on CT scanning, associated in one patient with neurological disorders. One patient with frontal sinusitis and meningeal involvement died despite therapy. One patient with limited maxillary sinusitis who underwent surgical satisfactory resection and antifungal therapy was successfully treated without relapse 12 months later. One patient with orbital and cavernous sinus extension of ethmoiditis was successfully cured with antifungal therapy by itraconazole. Our results confirm the necessity of early diagnosis when clinical and CTscanning are suggestive and the curability of aspergillus sinusitis.

Evolutionary DNA variation in the genus hypochaeris

The genome size and the base composition (GC%) of eight Hypochaeris species were determined by flow cytometry in order to establish the pattern of nuclear DNA variation within the genus. The species analysed showed an almost fivefold range of variation from 1.68 pg in H. cretensis to 8.10 pg in H. uniflora. This variation in DNA content is greater between taxonomic sections of Hypochaeris species than within a section. There was no correlation between 2C DNA content and GC% indicating that neither the GC fraction nor the AT fraction were preferentially associated with variation in genome size. Because there is little heterochromatin, these results show that it is interspersed repeated sequences that are most probably implicated in this variation. From phylogenetic analysis, it is likely that genome size has evolved by loss of DNA content in some lineages and by gain in one lineage from an ancestral genome which was probably similar to genomes of intermediate size in Hypochaeris.

Risk factors for negative sputum acid-fast bacilli smears in pulmonary tuberculosis: results from Dakar, Senegal, a city with low HIV seroprevalence.

SETTING: Two teaching hospitals in Dakar, Senegal, a West African country with a low prevalence of human immunodeficiency virus (HIV) infection. OBJECTIVE: To determine whether patients with HIV-associated pulmonary tuberculosis have fewer acid-fast bacilli (AFB) in their sputum as assessed by routine microscopy, and to correlate the findings with systematically obtained clinical, radiographic and laboratory variables. DESIGN: Prospective study from November 1995 to October 1996 of 450 consecutive patients diagnosed with pulmonary tuberculosis. RESULTS: Tuberculosis was diagnosed in 380 patients (84.4%) by positive bacteriology, in 61 (13.6%) by a favorable response to anti-tuberculosis chemotherapy, and in nine (2.0%) by the presence of a miliary radiographic pattern. Forty (8.9%) patients were HIV-seropositive. AFB-negative smears were found in 14/40 (35.0%) of the HIV-seropositive patients with pulmonary tuberculosis compared with 71/410 (17.3%) of the seronegative patients (risk ratio [RR] = 2.02, 95% confidence interval [CI] 1.26-3.24, P = 0.01). Multivariate analysis revealed that AFB smear negativity was associated with absence of cavitation (P = 0.002), lack of cough (P = 0.005), the presence of HIV seropositivity (P = 0.02), a CD4+ cell count above 200/mm3 (P = 0.02), and age over 40 years (P = 0.03). CONCLUSIONS: Compared with HIV-seronegative patients with pulmonary tuberculosis, seropositive patients in Dakar, Senegal, are more likely to have negative sputum-AFB smears. This phenomenon has now been observed in seven of eight sub-Saharan African countries with varying HIV seroprevalence from which reports are available.

[Malaria prophylaxis]. / Prophylaxie du paludisme.

Malaria, occurring in 1 to 2% of unprotected travellers to sub-Saharian Africa, remains a real risk because of its potential severity. In Asia or Latin America, the risk appears to be much lower, and in some cases, prevention can be limited to measures to avoid mosquito bites. Chemoprophylaxis by chloroquine-proguanil, mefloquine or, less frequently cyclines, is efficacious but poor compliance and frequent adverse events limits its interest. No regimen is totally effective and malaria must be considered in any traveller coming back from an endemic area with fever, even still receiving an appropriate prophylaxis.