Hidden hotspots of amphibian biodiversity in China

Identifying and protecting hotspots of endemism and species richness is crucial for mitigating the global biodiversity crisis. However, our understanding of spatial diversity patterns is far from complete, which severely limits our ability to conserve biodiversity hotspots. Here, we report a comprehensive analysis of amphibian species diversity in China, one of the most species-rich countries on Earth. Our study combines 20 y of field surveys with new molecular analyses of 521 described species and also identifies 100 potential cryptic species. We identify 10 hotspots of amphibian diversity in China, each with exceptional species richness and endemism and with exceptional phylogenetic diversity and phylogenetic endemism (based on a new time-calibrated, species-level phylogeny for Chinese amphibians). These 10 hotspots encompass 59.6% of China's described amphibian species, 49.0% of cryptic species, and 55.6% of species endemic to China. Only four of these 10 hotspots correspond to previously recognized biodiversity hotspots. The six new hotspots include the Nanling Mountains and other mountain ranges in South China. Among the 186 species in the six new hotspots, only 9.7% are well covered by protected areas and most (88.2%) are exposed to high human impacts. Five of the six new hotspots are under very high human pressure and are in urgent need of protection. We also find that patterns of richness in cryptic species are significantly related to those in described species but are not identical.

First national record of Microhylahmongorum Hoang, Nguyen, Phan, Pham, Ninh, Wang, Jiang, Ziegler and Nguyen, 2022 (Anura, Microhylidae, Microhyla) in China

Background

To date, 10 species of the genus Microhyla have been recorded in China, of which six were distributed in Yunnan Province. Microhylahmongorum Hoang, Nguyen, Phan, Pham, Ninh, Wang, Jiang, Ziegler, and Nguyen, 2022 was also speculated to be distributed in Xishuangbana, Yunnan Province, China. However, there is no evidence of documentation of M.hmongorum.

New information

We report the first country record of Microhylahmongorum, based on specimens collected from Yunnan border region. Morphologically, the specimen was consistent with the original descriptions of M.hmongorum. Phylogenetically, the sequences of the specimens from China clustered with the sequence of type specimens of M.hmongorum from Vietnam, with uncorrected pairwise distances of 0.9% at the 16S gene fragment analysed. Therefore, we report M.hmongorum as a new record species in China.

[Observation on the persistence period and transmission of residual microfilaremia with medium and higher density]

OBJECTIVE

To explore the persistence period of medium and higher density of microfilaremia and its role in the transmission of filariasis in areas with filariasis basically eradicated.

METHODS

The residual microfilaremia was followed up and the population were regularly examined by thick blood film assay. Culex quinquefaciatus were dissected to determine the natural infection rate and density of filarial larvae. The filarial antibody levels were detected by using IFAT.

RESULTS

Two cases with medium and higher density of microfilaremia were found to be microfilaremia positive for twelve years. The natural infection rate and density of filarial larvae in Culex quinquefasciatus dropped down year by year, one case of new microfilaremia was found in the sixteenth year.

CONCLUSION

The persistence period of residual medium and higher density of microfilaremia lasted for more than twelve years. The individual residual medium and higher density of microfilaremia cases still possess the potential for transmission of filariasis.

Association study of neuregulin 1 gene with schizophrenia

A number of studies have indicated that 8p22-p12 is likely to harbor schizophrenia susceptibility loci. In this region, the candidate gene of interest, neuregulin 1 (NRG1), may play a role in the pathogenesis of schizophrenia. Then in the present study, we performed the linkage disequilibrium to determine the association between three genetic variants (SNPs: rs3924999, rs2954041, SNP8NRG221533) on NRG1 gene and schizophrenia in 246 Chinese Han schizophrenic family trios using PCR-based restriction fragment length polymorphism method and denaturing high-performance liquid chromatography. The transmission disequilibrium test analysis for each variant showed a significant difference between two transmitted alleles even after Bonferroni correction (rs3924999, P=0.007752; rs2954041, P=0.0009309; SNP8NRG221533, P=0.012606). The global chi(2) test for haplotype transmission also revealed a strong association (chi(2)=46.068, df=7, P&<0.000001). Our results suggest that the NRG1 gene may play a role in conferring susceptibility to the disease.

Tetrandrine inhibited chronic "inflammatory" pulmonary hypertension in rats

AIM

To study the effects of tetrandrine (Tet), on pulmonary hypertension.

METHODS

An "inflammatory" chronic pulmonary hypertension induced by monocrotaline (Mon) in rats was used.

RESULTS

Tet 50, 100, and 150 mg.kg-1.d-1 i.g. 3 wk inhibited Mon-induced increase of pulmonary artery pressure (PAP) by 23.8%, 34.9% (P < 0.05), and 42.0%, (P < 0.05); the right heart index by 2.0%, 25.0%, and 30.0% (P < 0.05) respectively compared with those from Mon group, without significant influence on the systemic artery pressure (SAP). Using histological exam by Verhoeff elastic stain and computer scanning analysis, it was found that Tet (100 mg.kg-1.d-1) for 3 wk, inhibited the increase of medial thickness and cross sectional area by 57.8% (P < 0.01) and 54.6% (P < 0.01), respectively vs Mon group.

CONCLUSION

Tet ameliorated the development of pulmonary vascular and lung tissue injury induced by Mon in rats.

[The expression of C-FOS, C-JUN and phosphotyrosine gene products in lung cancer]

An immunohistochemical study on C-FOS, C-JUN and phosphotyrosine (P-Tyr) cancer gene products was performed. The results showed that C-FOS had the lowest frequency of expression and P-Tyr had the highest. The positive reactions of the three cancer gene products were observed in the nucleus, nuclear membrane and cytoplasm. The expression of C-FOS in normal bronchial and alveolar tissue was 3.8% and 1.6% respectively. But in lung cancer it was 60%. The simultaneous positive expression of C-FOS and C-JUN was 56% (54 cases). Negative C-FOS and positive C-JUN was 32%. Positive C-FOS and negative C-JUN was less than 4% (4 cases). Although C-FOS and C-JUN formed a hetero-dimer by zipper structure, the C-FOS had the ability of single expression.

[1,017 cases of posterior chamber IOL implantation]

Based on 1,017 consecutive cases (1,119 eyes) of modern extracapsular extraction with posterior chamber IOL implantation, the authors report their experience in the management of 11 complications, such as turbid posterior capsule, iris synechiae, pupil capture, etc. The period of follow-up ranged from 2 to 68 months, averaging 18.4 months. Disregarding 76 eyes of low vision due to preoperative fundus diseases, 981 (94.1%) of the 1,043 eyes operated achieved corrected vision of 0.5 or better.

[Determination of zinc, copper, iron and zinc/copper ratio in the hair of active pulmonary tuberculosis patients]

The determination of zinc (Zn), copper (Cu), iron (Fe) and zinc/copper ratio (Zn/Cu) in hair in 70 active pulmonary tuberculosis and 51 healthy individuals were reported. The Zn and Zn/Cu in hair of patients with pulmonary tuberculosis, in cases with cavities or noncavities and in cases with smear positive or negative sputum were lower than that of healthy individuals (P less than 0.01). But there was no difference in the hair Fe between the patients and healthy individuals.

Protein kinase C-like immunoreactivity in rod bipolar cells of the rat retina: a developmental study

In the retina of a variety of vertebrate species, a monoclonal antibody against protein kinase C (PKC) has been shown to label preferentially bipolar cells. Although the functional consequences of PKC activation in these cells is yet to be revealed, the present study was motivated in part by the possibility that the antibody might be used as a selective marker for examining the development of bipolar cells in the rat retina. Here, the developmental pattern and the dynamic changes of retinal cells expressing PKC-like immunoreactivity (PKC-LI) were studied and analyzed throughout postnatal life until adulthood. Upon its initial detection by immunohistochemistry on postnatal day (PD)-10, faint PKC-LI was limited to the central region of the retina, labeling cell bodies located at the scleral margin of the inner nuclear layer (INL) adjacent to the outer plexiform layer (OPL). On subsequent days, PKC-LI spread progressively to the peripheral retina and axon terminal bulbs at the vitreal margin of the inner plexiform layer (IPL) began showing the first signs of immunoreactive labeling. Not until PD-15, the time of eye opening, did PKC-LI in these cells increase to the extent such that their thin axons were immunoreactive. Each of these axons traversed the entire thickness of the IPL and divided into two or three short branches before ending as enlarged terminal bulbs. The morphology and the location of PKC-LI cells in both the developing and adult retina observed in our study are consistent with them being rod bipolar cells. By the end of the fourth postnatal week, the rod bipolar cells appeared mature, resembling those found in the adult.(ABSTRACT TRUNCATED AT 250 WORDS)

Histogenesis of corticotropin releasing factor-like immunoreactive amacrine cells in the rat retina

The histogenesis of amacrine cells expressing corticotropin releasing factor-like immunoreactivity (CRF-LI) was examined in the rat retina by incorporating [3H]thymidine autoradiography and immunohistochemistry. Our results indicate that, during the period of amacrine cell generation, the population of CRF-LI amacrine cells are generated within a window of time from gestational days (ED)-16 to -20; the majority of them are produced by ED-18. No CRF-LI cells have been found to be 'born' postnatally. The histogenetic pattern of these cells follows a center-to-periphery gradient. Furthermore, CRF-LI cells in both the inner nuclear layer and the ganglion cell layer are generated in the same histogenetic wave and follow an identical temporo-spatial pattern. These results are consistent with and extend our previous findings of a differential change in CRF-LI cell density and total cell number during postnatal development.

Postnatal development of corticotropin releasing factor-like immunoreactive amacrine cells in the rat retina

The postnatal development of the corticotropin releasing factor-like immunoreactive (CRF-LI) amacrine cells was investigated in the Long-Evans rat retina. The pattern of development of CRF-LI cells was studied by immunohistochemistry, their cell number and density throughout the first two weeks of postnatal development were analyzed, and correlative measures of CRF-LI content were obtained using radioimmunoassay (RIA). The overall pattern of CRF-LI development, as revealed by either method, is characterized initially by faint staining and low content, respectively, which began to increase in staining intensity and content until a peak was reached around postnatal day (PD)-15, the time of eye opening. In determining cell number and density, emphasis was placed on the relationship between the development of CRF-LI neurons in the inner nuclear layer (INL) and that in the ganglion cell layer (GCL). Such quantitative analyses revealed a series of dynamic shifts in the distribution of CRF-LI cell density in both a horizontal orientation and a vertical orientation prior to PD-15. Horizontally, the shift involved a center-to-periphery density gradient which disappeared progressively as the retina matured. Vertically, a reciprocal change in total cell number occurred; the number of CRF-LI cells in the INL decreased while that in the GCL increased. These changes stabilized by PD-15 and, by PD-19, the CRF-LI cells appeared morphologically mature.

Optic nerve sectioning does not affect the development of the retina

The development of the retina of the albino rat was studied after sectioning of the optic nerves on the 2nd postnatal day. The 2nd day represents a stage at which the retina shows only the ganglion cell layer clearly delineated from an undifferentiated mass. Section of optic nerves at this stage did not affect the subsequent retinal development. Both control and experimental eyes developed at the same pace. Some minor degrees of 'retardation' e.g. the sizes of outer segments, appeared to deviate in the experimental retinae.

Metabolic and phagocytic activities of the mouse retina after 6-hydroxydopamine treatment

The activities in mouse retinae were evaluated after 6-hydroxydopamine injection. A significant increase in labeled leucine uptake was evident in the photoreceptor layer. Latex uptake in the pigment epithelium showed no changes. Denervation of catecholaminergic terminals inside the retinae thus affected the metabolism of photoreceptors.