Ongoing declines for the world's amphibians in the face of emerging threats

Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.

Psychosis and brain volume changes during the first five years of schizophrenia

The underlying mechanisms explaining brain volume changes in schizophrenia are not yet understood, but psychosis might be related to these changes. Forty-eight patients with first-episode schizophrenia underwent Magnetic Resonance Imaging brain scanning at inclusion and after five years. An association was found between longer duration of psychosis, larger gray matter volume decrease and larger ventricular volume increase. These findings strongly suggest that psychosis contributes to brain volume reductions found in schizophrenia.

High-performance liquid chromatographic method for determination of amodiaquine, chloroquine and their monodesethyl metabolites in biological samples

A high-performance liquid chromatographic method for determination of amodiaquine (AQ), desethylamodiaquine (DAQ), chloroquine (CQ) and desethylchloroquine (DCQ) in human whole blood, plasma and urine is reported. 4-(4-Dimethylamino-1-methylbutylamino)-7-chloroquinoline was used as internal standard. The drugs and the internal standard were extracted into di-isopropyl ether as bases and then re-extracted into an acidic aqueous phase with 0.1 M phosphate buffer at pH 4.0 for AQ samples and at pH 2.5 for CQ filter paper samples. A C(18) column was used and the mobile phase consisted of methanol-phosphate buffer (0.1 M, pH 3)-perchloric acid (250: 747.5:2.5, v/v). The absorbance of the drugs was monitored at 333 nm and no endogenous compound interfered at this wavelength. The limit of quantification in whole blood, plasma and urine was 100 nM for AQ and DAQ (sample size 100 microliter) as well as for CQ and DCQ in blood samples dried on filter paper. For 1000 microliter AQ and DAQ samples, the limit of quantification was 10 nM in all three biological fluids. The within-assay and between-assay coefficients of variations were always <10% at the limits of quantification. Plasma should be preferred for the determination of AQ and DAQ since use of whole blood may be associated with stability problems.

A vivid model illustrating chiral recognition induced by achiral structures

If diastereomeric complexes are adsorbed on a surface or if they include a molecule of solvent, two points of attractive interaction between the chiral species of the complex can be sufficient for mutual chiral recognition of these species. In special cases even one single point of interaction is sufficient. This extension of the three-point contact rule of Dalgliesh, first observed in chiral ligand-exchange chromatography, can be demonstrated by using hands.

Determination of chloroquine and its desethyl metabolite in whole blood: an application for samples collected in capillary tubes and dried on filter paper

A high performance liquid chromatography method for analysis of chloroquine and desethylchloroquine was adapted for 75 microliters aliquots of whole blood obtained by finger-prick and dried on filter paper. The precision of the method was satisfactory at whole blood concentrations of 40 nmol/L (coefficient of variation, 5%). The dried samples were stable for at least 7 weeks at 20 degrees C. The concentrations in venous whole blood and in dried samples correlated well. The correlation coefficient was 0.99 for chloroquine and 0.97 for desethylchloroquine. Chloroquine concentrations were marginally but significantly higher in venous whole blood. When fitted to a linear equation (y = bx + a) the relationship was y = 0.96x + 0.03. Desethylchloroquine concentrations did not differ significantly in venous whole blood and in finger-prick blood dried on filter paper. The method is specific and sensitive enough for pharmacokinetic studies and can be used in areas with limited technical facilities.

Differential requirement for CD18 in T-helper effector homing

To understand the integrin requirements of T-helper (T(H)) effector subsets, we investigated the contribution of CD18 (beta(2) integrin) to T(H)1 and T(H)2 function in vitro and in relevant disease models. CD18-deficient (Itgb2(-/-)) T cells showed largely normal in vitro function. Compared with wild-type mice, Itgb2(-/-) mice were better able to resolve Leishmania major infection and generated a superior T(H)1 immune response, as assessed from draining lymph nodes. In contrast, T(H)2-dependent allergic lung disease was markedly impaired in mutant mice. In both models, development of T(H)1 and T(H)2 cells in spleens was normal, but accumulation of T(H)2 (not T(H)1) cells at inflammatory sites was reduced. Thus, CD18 is selectively required for T(H)2, but not T(H)1, homing and has a minimal influence on T-effector development. These findings suggest a new integrin-based therapeutic approach in which the outcomes of diverse diseases may be favorably influenced by altering the homing of T(H)2 cells.

Pentamidine concentrations in plasma, whole blood and cerebrospinal fluid during treatment of Trypanosoma gambiense infection in Côte d'Ivoire

Pentamidine concentrations in plasma, whole blood and cerebrospinal fluid (CSF) were determined in 11 patients with Trypanosoma gambiense infection without involvement of the central nervous system in Côte d'Ivoire. Blood samples were drawn during a 48 h period after the first and last dose of pentamidine dimesylate given as 10 intramuscular injections on alternate days. Maximum plasma concentrations were generally attained within one hour after injection but varied extensively (420-13420 nmol/litre). The median plasma concentration 48 h after the last dose was approximately 5 times higher than that after the first dose. The ratio between whole blood and plasma concentration was approximately 2. Small amounts of the drug were found in the CSF after the last dose. The findings showed inter-individual differences in the pharmacokinetics of pentamidine. The currently recommended daily dose regimen could be questioned, as drug accumulation was pronounced. All patients were cured and the concentrations attained should be considered as parasiticidal. Further studies on the kinetics and distribution after single and multiple doses of pentamidine as well as studies on the possible relationship between adverse effects and plasma concentrations are, however, needed.

Brain volume reductions in medication-naive patients with schizophrenia in relation to intelligence quotient

BACKGROUND

Global brain abnormalities such as brain volume loss and grey- and white-matter deficits are consistently reported in first-episode schizophrenia patients and may already be detectable in the very early stages of the illness. Whether these changes are dependent on medication use or related to intelligence quotient (IQ) is still debated.

METHOD

Magnetic resonance imaging scans were obtained for 20 medication-naive patients with first-episode schizophrenia and 26 matched healthy subjects. Volume measures of total brain grey and white matter, third and lateral ventricles and cortical thickness/surface were obtained. Differences between the groups were investigated, taking into account the effect of intelligence.

RESULTS

Medication-naive patients showed statistically significant reductions in whole-brain volume and cerebral grey- and white-matter volume together with lateral ventricle enlargement compared to healthy subjects. IQ was significantly lower in patients compared to controls and was positively associated with brain and white-matter volume in the whole group. No significant differences in cortical thickness were found between the groups but medication-naive patients had a significantly smaller surface in the left superior temporal pole, Heschl's gyrus and insula compared to controls.

CONCLUSIONS

Our findings suggest that brain volume loss is present at illness onset, and can be explained by the reduced surface of the temporal and insular cortex. These abnormalities are not related to medication, but IQ.

Slow chloroguanide metabolism in Tanzanians compared with white subjects and Asian subjects confirms a decreased CYP2C19 activity in relation to genotype

BACKGROUND

We have previously found decreased CYP2C19 activity in Tanzanians tested with mephenytoin and omeprazole in relation to genotype when compared with white and Asian subjects.

OBJECTIVE

We investigated the impact of CYP2C19 genotype and phenotype on chloroguanide (INN, proguanil) metabolism to its metabolites cycloguanil and 4-chlorophenylbiguanide.

METHODS

A single oral chloroguanide dose was given to 25 healthy Tanzanian subjects with CYP2C19 genotypes (CYP2C19*1, CYP2C19*2, and CYP2C19*3). Homozygous wild-type and mutated genotype groups were chosen randomly, but the heterozygous genotype group was chosen with a range in phenotype. We used a novel HPLC method for drug determination.

RESULTS

Pharmacokinetics of chloroguanide did not differ between groups. Maximum plasma concentration (Cmax) and area under the plasma concentration versus time [AUC(0-infinity)] for cycloguanil was significantly lower (t test P < .05) in the homozygously mutated group compared with the homozygously wild-type group. There were similar significant group differences of median urinary excretion. The chloroguanide/cycloguanil ratio closely correlated (r(s) = .87) with omeprazole metabolic ratio, confirming that Tanzanian subjects are generally slower CYP2C19 metabolizers. It also confirms that CYP2C19 genotype and phenotype predicts cycloguanil formation. In addition, a 3-hour plasma sample metabolic ratio also seems to be a proper time for omeprazole phenotyping in Tanzanian subjects. Because the plasma concentrations of cycloguanil and 4-chlorophenylbiguanide covary (r(s) = .89), it is now suggested that their formation be catalyzed by the same enzyme (ie, CYP2C19) through a common intermediate, the structure of which is also presented.

CONCLUSIONS

As shown in an earlier study, also with a third substrate, Tanzanians have a lower capacity to form cycloguanil than white and Asian subjects. Individuals with two mutated alleles have lower metabolic capacity than individuals with two wild-type alleles or individuals in the heterozygous group, which may lead to chloroguanide therapeutic failure. This knowledge should be important when selecting appropriate patients and doses of chloroguanide in different populations.

Pharmacokinetics and adverse reactions after a single dose of pentamidine in patients with Trypanosoma gambiense sleeping sickness

1. Plasma concentrations of pentamidine were measured up to 1-8 months after a single 2 h i.v. infusion of 3.0 to 4.8 mg kg-1 pentamidine isethionate in 11 patients with late stage Trypanosoma gambiense sleeping sickness. 2. Maximum plasma drug concentrations varied between 713 and 2461 nmol 1-1. After termination of infusion, a rapid distribution phase over 10 min was followed by a slower distribution phase and an elimination phase prolonged over weeks to months. 3. The 'terminal' elimination rate constant could be determined in six patients and subsequent kinetic calculations showed a three to fourfold variation in plasma clearance and 'terminal' half-life (median 1126 (range 553-2036) ml min-1 and 265 (107-446) h, respectively). The median apparent volume of distribution (Vss) was 11,850 1. Renal clearance accounted for a median of 11% of total plasma clearance, indicating that metabolism is a major route of pentamidine elimination in man. 4. Side effects were few and mild and a slight or moderate decrease in blood pressure was the most common registered adverse reaction observed in four subjects. 5. The prolonged elimination of pentamidine seems inconsistent with the present recommended dosage regimen of pentamidine for treatment of trypanosomiasis of 7 to 10 parenteral doses given once daily or every second day.

A vivid model of chiral recognition

Hands can be used to demonstrate the three-point model of chiral recognition. The points of attachment are thumb, forefinger, and middle finger. This vivid model has the advantages of simplicity, perspicuity, and availability at any time, although two persons are necessary. It can be shown that two interactions are not sufficient for chiral recognition but that three attractive or two attractive and one repulsive attraction are needed. It can also be used to explain some possibilities of weakening or elusion of the three-point model.

Perpetuating effects of androgen deficiency on insulin resistance

Background/Objectives

Androgen deprivation therapy (ADT) is commonly used for treatment of prostate cancer, but is associated with side effects such as sarcopenia and insulin resistance. The role of lifestyle factors such as diet and exercise on insulin sensitivity and body composition in testosterone-deficient males is poorly understood. The aim of the present study was to examine the relationships between androgen status, diet, and insulin sensitivity.

Subjects/Methods

Middle-aged (11–12-yo) intact and orchidectomized male rhesus macaques were maintained for two months on a standard chow diet, and then exposed for six months to a Western-style, high-fat/calorie-dense diet (WSD) followed by four months of caloric restriction (CR). Body composition, insulin sensitivity, physical activity, serum cytokine levels, and adipose biopsies were evaluated before and after each dietary intervention.

Results

Both intact and orchidectomized animals gained similar proportions of body fat, developed visceral and subcutaneous adipocyte hypertrophy, and became insulin resistant in response to the WSD. CR reduced body fat in both groups, but reversed insulin resistance only in intact animals. Orchidectomized animals displayed progressive sarcopenia, which persisted after the switch to CR. Androgen deficiency was associated with increased levels of interleukin-6 and macrophage-derived chemokine (CCL22), both of which were elevated during CR. Physical activity levels showed a negative correlation with body fat and insulin sensitivity.

Conclusion

Androgen deficiency exacerbated the negative metabolic side effects of the WSD, such that CR alone was not sufficient to improve altered insulin sensitivity, suggesting that ADT patients will require additional interventions to reverse insulin resistance and sarcopenia.

Interleukin-12 inhibits eosinophil differentiation from bone marrow stem cells in an interferon-gamma-dependent manner in a mouse model of asthma

BACKGROUND

Intrapulmonary administration of IL-12 has been shown to inhibit the number of eosinophils in lung murine models of asthma, but the precise mechanism of this inhibition has not been reported. The purpose of this study was to examine whether IL-12 treatment inhibits bone marrow eosinophilopoiesis, and to elucidate the role of IFN-gamma in this process.

OBJECTIVE

To elucidate the in vivo and in vitro effects of IL-12 on eosinophil differentiation from murine bone marrow (BM) stem cells, and to examine the mechanistic role of IFN-gamma in this process.

METHODS

Allergen-sensitized BALB/c mice were administered low doses of intranasal IL-12 at the time of allergen challenge, and the number of eosinophils in BM was determined 3 days later. The direct actions of IL-12 on eosinophil differentiation from BM cells were determined in vitro. The mechanistic role of IFN-gamma was assessed by measuring IFN-gamma induction by IL-12 in BM cell cultures, and through the use of IFN-gamma KO mice.

RESULTS

Treatment of allergic mice with intrapulmonary IL-12 (1 ng or 10 ng) reduced eosinophils in BM by 43%. Culture of BM cells from allergen-sensitized mice with IL-3 + IL-5 induced eosinophil differentiation in vitro. Addition of IL-12 to these cultures inhibited eosinophil differentiation, with maximal inhibition (45%) occurring at 10 ng/mL IL-12 concentration. IL-12 induced IFN-gamma production from BM cultures, and failed to inhibit eosinophil differentiation in IFN-gamma-knockout mice, indicating a critical mechanistic role for IFN-gamma.

CONCLUSION

This study demonstrates that IL-12 selectively inhibits BM eosinophilopoiesis, and that this effect is mediated by IFN-gamma. Intrapulmonary IL-12 has suppressive effects on BM eosinophilopoiesis that may represent a novel mechanism contributing to the anti-eosinophilic effects of IL-12 in allergic airway disease.

Developmental control of integrin expression regulates Th2 effector homing

Integrin CD18, a component of the LFA-1 complex that also includes CD11a, is essential for Th2, but not Th1, cell homing, but the explanation for this phenomenon remains obscure. In this study, we investigate the mechanism by which Th2 effector responses require the LFA-1 complex. CD11a-deficient T cells showed normal in vitro differentiation and function. However, Th2 cell-dependent allergic lung disease was markedly reduced in CD11a null mice and wild-type mice given LFA-1 inhibitors, whereas control of infection with Leishmania major, a Th1-dependent response, was enhanced. In both disease models, recruitment of IL-4-, but not IFN-gamma-secreting cells to relevant organs was impaired, as was adhesion of Th2 cells in vitro. These diverse findings were explained by the markedly reduced expression of CD29, an alternate homing integrin, on Th2, but not Th1, cells, which precludes Th2 homing in the absence of CD11a. Thus, murine Th1 and Th2 cells use distinct integrins for homing, suggesting novel opportunities for integrin-based therapeutic intervention in diverse human ailments influenced by Th2 cells.

Classic Kaposi's sarcoma in southern Sardinia, Italy

The first examination of classical Kaposi's sarcoma incidence in southern Sardinia (Italy) in 1998–2002 found the highest rate recorded in the island of 2.49 per 100 000 per year (standardised).

Chronic liver disease in transfusion-dependent thalassemia: liver iron quantitation and distribution

The quantitative and/or qualitative distribution of liver iron was assessed in 81 transfusion-dependent thalassemia major patients with chronic liver disease (36 with chronic active hepatitis, 23 with chronic persistent hepatitis, 22 with siderosis). Viral marker studies showed only 3 cases with both HBsAg and anti-HBc positivity in the serum, while the others had anti-HBc and anti-HBs or only anti-HBs or no B viral markers. A significantly higher iron overload was found in chronic hepatitis, particularly chronic active hepatitis, than in siderosis. The increased iron overload may be due to less intensive chelation treatment, higher intestinal absorption secondary to lower mean Hb levels, and/or to liver inflammation-dependent iron deposition. The liver iron overload in turn amy facilitate the development or persistence of chronic progressive liver disease.

Breeding habits of the Indian pangolin (Manis crassicaudata) in Potohar Plateau, Pakistan

The Indian pangolin (

[Which psychological support for couples seeking medical assistance for procreation?]

OBJECTIVES

The objective of our qualitative study was to define modalities of psychological support to be offered to couples seeking medically assisted procreation.

MATERIAL AND METHODS

Forty couples participated in a semi-structured videotaped interview, which touched on themes such as personal and family histories, the couple's relationship, etc. We focused on the "narrative mobility", that is the way in which the couples transmit their personal and family history during the interview and the interviewer's impression that he may or may not share this with the couples.

RESULTS

Observed differences in narrative mobility led us to distinguish three groups of couples and to propose various types of psychological support.

DISCUSSION AND CONCLUSION

This exploratory study, with its interest for the narrative mobility, concerns the couples' capacity to stand back from their own story as responsible interlocutors. We made the hypothesis that this capacity is linked to their capacity to handle their emotional stress, to act as partners to the medical team and to prepare themselves for their future parenthood.

One-step detection and genotyping of human papillomavirus in cervical samples by reverse hybridization

This study describes a nonisotopic polymerase chain reaction-reverse hybridization-based method (PCR-RH) for the one-step detection and genotyping of anogenital human papillomavirus (HPV) in a microwell format. HPV DNA was amplified and labeled by PCR using GP5+/GP6+ primers. Labeled amplicons were hybridized to 20 HPV type-specific capture probes anchored to the surface of plastic microwells and detected by an immunoenzymatic assay. Assay sensitivity was <50 pg labeled amplicon, and no cross-reactivity was observed, as determined by hybridizing serial dilutions of labeled PCR products to either matched or mismatched capture probes. The assay was tested on 66 clinical samples (23 specimens with normal histology, I fibropapilloma, 26 cervical intraepithelial neoplasia grade 1 [CIN1], 9 CIN2, and 7 CIN3) and compared with a method based on restriction fragment length polymorphism (RFLP) of PCR products. PCR-RH and PCR-RFLP performed equally well on clinical samples. The overall HPV detection rate was similar: 65.1% (43/66) for PCR-RH and 57.6% (38/66) for PCR-RFLP. HPV DNA was found in all CIN2 and CIN3 samples by both methods; however, PCR-RH detected more positives among normal biopsy samples and CINI cases. Overall, there was good agreement between the two genotyping methods, but RH yielded fewer cases with undetermined HPV genotype.

Determination of chloroquine in dried blood spots on filter paper: importance of sample handling

During determination of chloroquine (CQ) and its main metabolite desethylchloroquine (CQM) in blood samples applied to filter paper, we observed contamination of the paper by CQ. CQ and CQM in the dried spots were analyzed with two different high performance liquid chromatographic methods. The identity of the contamination was confirmed as CQ with mass spectrometry.

Rise in temperature causes decreased fitness and higher extinction risks in endemic frogs at high altitude forested wetlands in northern Pakistan

The larvae of some amphibian species grow and develop more slowly at lower temperature and attain larger body size at the end of metamorphosis, but this is not true for all amphibians. We have for the first time provided empirical data by using a combination of field and lab-based studies with a robust sample size (360 adults, 1000 tadpoles) for Hazara Torrent Frog (Allopaa hazarensis) and Murree Hills Frog (Nanorana vicina). In this study, we examined how tadpoles responded to different temperatures through metamorphosis, body size, developmental complications or deformities, fitness and survival. We found that the tadpoles of A. hazarensis and N. vicina showed the same response to elevated temperatures under laboratory conditions including faster metamorphosis, reduction in the body size, more frequent developmental complications or deformities such as edema and tail kinks, lower fitness and higher mortality at elevated temperatures (>26 °C). The comparison of thermal sensitivity between the two species showed that N. vicina was more sensitive to higher temperatures. Pakistan has been experiencing changes in climatic patterns, and the ecosystems in northern Pakistan are losing biodiversity due to increasing temperature, frequency of drought and intensity of floods. It is feared that these frogs may experience local extinction in future. Our findings contribute to filling the information gap regarding impacts of temperature increase on biodiversity of high altitude forested montane ecosystems and is an important contribution to future studies associating biodiversity and climate change.

The tadpoles of Murree Hills Frog Nanorana vicina (Anura: Dicroglossidae)

The genus Nanorana, also called Yunnan Slow Frogs (Frank Ramus 1995), belongs to the family Dicroglossidae. Murree Hills Frog N. vicina, is an endemic species of Southeast Asian uplands in Pakistan and India and was first reported by Stoliczka (1872) from Murree, Punjab Province, Pakistan. Later Rais et al. (2014) recaptured it from its type locality and described morphology of one juvenile female and one adult male. The species is listed as Least Concern in IUCN Red List of Threatened Species while the EDGE (Evolutionarily Distinct and Globally Endangered) score is 2.64. In Pakistan, it is reported from brook water springs and streams of Murree, Galiat (North Punjab), Ayubia (Khyber Pakhtunkhwa), and parts of Azad Jammu and Kashmir (Rais et al. 2014). Although the adult form has been characterized (Khan 2006; Rais et al. 2014), the morphology of the tadpoles have not yet been described. The current study aimed to describe external morphology and morphometry of tadpoles of N. vicina.