[Impact of plateau environment on seminal characteristics of native Tibetans and immigrated Tibetan Hans]

OBJECTIVE

To investigate the characteristics of the semen parameters of native Tibetans and immigrated Tibetan Hans in the high-altitude area and analyze the influence of altitude adaptation on male fertility.

METHODS

This study included 1 563 infertile male patients, including 698 native Tibetans and 865 immigrated Tibetan Hans, and 56 normal fertile men, including 33 native Tibetans and 23 Tibetan Hans. We obtained semen samples from the subjects for routine semen analysis and sperm DNA fragmentation index (DFI) examination and collected peripheral blood for determination of the reproductive hormone levels.

RESULTS

In the infertile patients, the native Tibetans, as compared with the immigrated Hans, showed significantly higher incidence rates of azoospermia (5.87% vs 2.89%, P <0.05), severe oligozoospermia (3.15% vs 1.73%, P <0.05) and abnormal seminal viscosity (43.12% vs 25.89%, P<0.01), but no statistically significant differences in the percentages of normozoospermia (81.08% vs 87.39%, P >0.05), oligozoospermia (5.44% vs 3.93%, P >0.05), severe asthenozoospermia (4.44% vs 4.04%, P >0.05) or severe teratozoospermia (4.58% vs 6.59%, P >0.05). In the normal fertile men, there were no statistically significant differences between the native Tibetans and immigrated Hans in age (［32.42 ± 4.82］ vs ［34.57 ± 6.01］ yr, P >0.05), sperm concentration (［143.69 ± 85.74］ vs ［155.11 ± 82.56］ ×10⁶/ml, P >0.05), straight line velocity (［25.74 ± 3.94］ vs ［27.24 ± 3.46］ μm/s, P >0.05), percentage of morphologically normal sperm (［8.22 ± 4.35］ vs ［7.28±2.46］ %, P >0.05), total testosterone concentration (［17.97 ± 2.98］ vs ［15.72 ± 6.38］ nmol/L, P >0.05), or follicle stimulating hormone level (［5.51 ± 1.62］ vs ［4.17 ± 2.08］ IU/L, P >0.05). However, the immigrated Hans, in comparison with the native Tibetans, exhibited a higher sperm motility (［79.75 ± 14.67］ vs ［66.58 ± 17.21］%, P <0.05), a lower curvilinear velocity (［60.97 ± 2.71］ vs ［71.14 ± 82.13］ μm/s, P <0.05) and a lower level of luteinizing hormone (［4.28 ± 1.20］ vs ［5.84 ± 1.15］ IU/L, P <0.05).

CONCLUSIONS

During the acclimatization to the plateau hypoxia environment, the immigrated Tibetan Hans undergo adaptive changes in sperm concentration and motility and have lower incidence rates of azoospermia and severe oligozoospermia than native Tibetan males.

Fertility outcome of patients with testicular tumor: before and after treatment

Testicular cancer (TC) is the most curable type of cancer, with a survival rate of more than 95%. Oncologists are faced with the challenge that gonadotoxic cancer treatments can compromise future fertility, either temporarily or permanently. Our aim was to investigate the long-term effects of TC treatments on male fertility and on the offspring of patients who had received these treatments. Between January 1996 and December 2010, 125 eligible patients, ranging from 18 to 54 years (median age 36.3 ± 15.7), with unilateral TC underwent surgery, chemotherapy or radiotherapy at our center. Some of these patients had their semen samples cryopreserved in the Shanghai Human Sperm Bank. The clinical data were evaluated, and questionnaire and telephone follow-up surveys were given to all patients. The data were analyzed to determine the patients’ fertility status pre- and posttreatment. Of the 125 eligible patients, 93.6% (117/125) were accessible and were evaluated. Among 81 men who were married before diagnosis, 21 had conceived successfully before diagnosis and six reported azoospermia. Posttreatment conception was attempted by 73 men; of these, 16 conceived naturally and 19 conceived by artificial reproductive techniques, resulting in 37 healthy babies with no congenital malformations. Of the patients who had not conceived before treatment, 21.9% (21/96) banked their sperm and 23.8% of these patients (5/21) subsequently used the banked sperm. Retroperitoneal lymph node dissection, chemotherapy and radiotherapy were the most highly correlated with lack of conception post-TC treatment. Sperm banking should be recommended to TC patients with the desire for biological conception. There is no evidence to suggest that TC treatments are associated with birth defects or childhood malignancies.

[Ewing's sarcoma--report of 18 cases]

Eighteen cases of Ewing's sarcoma are presented. The mean age was 13 years. The male to female ratio was 2:1. Tumor occurred frequently in the long bones, especially the femur. The average course was 7 months. The main symptoms were pain, moderate fever, tumor mass with tenderness and leucocytosis. Diagnosis was established according to the clinical, radiological and pathological findings. In this series, the major treatment was radiotherapy alone or radiotherapy combined with chemotherapy. The mean survival time was 16 months with 2- and 5-year survival rate of 31% and 20%, respectively. Misdiagnosis and failure or interruption of the combined treatment were the main factors for poor prognosis.

Conservation between coding and regulatory elements of Rhizobium meliloti and Rhizobium leguminosarum dct genes

Complementation of Rhizobium leguminosarum dct mutants with a cosmid bank yielded Rhizobium meliloti homologs of the dctA, dctB, and dctD genes. The genes dctB and dctD are thought to form a two-component system which responds to the presence of C4-dicarboxylates to regulate expression of a transport protein encoded by dctA. DNA sequence analysis showed that dct coding and intergenic regions, including putative binding sites for the dctD protein and sigma 54-RNA polymerase, were highly conserved between these two Rhizobium species. Mutation of R. meliloti dctD showed that it was not essential for symbiotic nitrogen fixation but was needed for growth on succinate and the expression of a dctA-lacZ fusion gene in free-living cells. Hybridization of R. meliloti genomic DNA with probes representing the central portion of dctD potentially identified more than 20 similar regulatory genes, all of which are likely to depend upon the alternative sigma factor encoded by rpoN and stimulate transcription in a manner very similar to ntrC activation of glnA in enteric bacteria.

Functional regions and structural features of the gB glycoprotein of herpes simplex virus type 1. An analysis of linker insertion mutants

Glycoprotein B (gB) of Herpes simplex virus type 1 (HSV-1) plays an essential role in viral entry. A set of more than 100 HpaI (GTTAAC) linker insertion mutations and their derivatives were isolated in plasmids specifying the gB coding and flanking sequences. Mutations including addition, deletion and nonsense mutations at 34 independent sites were identified by DNA sequence analysis of 48 plasmids. A map was constructed for the ability of addition mutants to complement a gB-null virus. The expression of gB activity for some plasmids was temperature-dependent. Many complementation-negative plasmids inhibited the complementation activity of a plasmid specifying wild-type gB, suggesting an interaction between active and inactive molecules to form oligomers. The interaction was localized to 328 of the total of 904 amino acids comprising gB. Partial Endo H digestion of nonsense polypeptides revealed that five of the six potential N-linked oligosaccharide sites are glycosylated; the most C-terminal site appears not to be glycosylated. A number of mutations, including some on the cytoplasmic side, were identified that blocked processing, transport and secretion. Addition mutations that blocked processing of membrane polypeptides also blocked processing and secretion when combined into a nonsense mutant that by itself was processed and secreted. The previously predicted membrane spanning domain and the membrane orientation of the N-terminal portion of gB were confirmed.

[Midline malignant histiocytosis--diagnostic and prognostic study of 42 patients]

42 patients of midline malignant histiocytosis are reported. The differential diagnosis should be made carefully, for its clinical sign and pathologic picture are similar to some neoplasms, inflammatory or allergic diseases. The 3, 5 and 10 year survival rates are 52.4%, 38.1% and 21.4% respectively. The survival rate of those in the prodromal stage is the highest. The authors suggest that this disease probably belongs to the malignant tumor of mononuclear macrophage system and be a special type of malignant histiocytosis. It may be designated as the midline malignant histiocytosis.