Methylcobalamin as antagonist to transient ototoxic action of gentamicin

The objective of this study was to determine whether methylcobalamin inhibits the ototoxic action of gentamicin. Fourteen pigmented guinea pigs were randomly divided into experimental and control groups. Each animal in the experimental group was given a large single dose of gentamicin (125 mg/kg i.m.), followed by immediate administration of methylcobalamin (1 mg kg i.m.). In the control group, the animals received gentamicin only, at the same dose as the experimental group. The compound action potentials (CAPs) in the right ears of animals were measured using a signal processor before and 15, 30, 45, 60 and 75 min after injection of the drugs. The sound stimulus was presented by means of clicks and tone pips at 2, 4 and 8 kHz. Following the electro-physiological tests, the animal was sacrificed and prepared for scanning electron microscopic observation. There was prolongation of latency and diminution of amplitude of CAPs N1 and N2 15 min after injection of gentamicin. Although the N1-N2 intervals increased as the time after injection of gentamicin increased, the variations were still within normal ranges. In contrast, there was no prolongation of N1 latencies or N1-N2 intervals 30 min after injection in the experimental group. There were no marked changes in N1 or N2 amplitudes, compared with the results before injection, in the experimental group. The firing mechanism of the inner ear may be affected by a single dose of gentamicin. This suggests that the transient ototoxic action of gentamicin hardly affected the conductive function of the nerve fibres, even though the firing function of the inner ear was influenced. Methylcobalamin may inhibit the ototoxic side effects of gentamicin.

Activation of mitogen-activated protein kinases is required for alpha1-adrenergic agonist-induced cell scattering in transfected HepG2 cells

Activation of alpha1B-adrenergic receptors ((alpha1B)AR) by phenylephrine (PE) induces scattering of HepG2 cells stably transfected with the (alpha1B)AR (TFG2 cells). Scattering was also observed after stimulation of TFG2 cells with phorbol myristate acetate (PMA) but not with hepatocyte growth factor/scatter factor, epidermal growth factor, or insulin. PMA but not phenylephrine rapidly activated PKCalpha in TFG2 cells, and the highly selective PKC inhibitor bisindolylmaleimide (GFX) completely abolished PMA-induced but not PE-induced scattering. PE rapidly activated p44/42 mitogen-activated protein kinase (MAPK), p38 MAPK, c-Jun N-terminal kinase (JNK), and AP1 (c-fos/c-jun). Selective blockade of p42/44 MAPK activity by PD98059 or by transfection of a MEK1 dominant negative adenovirus significantly inhibited the PE-induced scattering of TFG2 cells. Selective inhibition of p38 MAPK by SB203850 or SB202190 also blocked PE-induced scattering, whereas treatment of TFG2 cells with the PI3 kinase inhibitors LY294002 or wortmannin did not inhibit PE-induced scattering. Blocking JNK activation with a dominant negative mutant of JNK or blocking AP1 activation with a dominant negative mutant of c-jun (TAM67) significantly inhibited PE-induced cell scattering. These data indicate that PE-induced scattering of TFG2 cells is mediated by complex mechanisms, including activation of p42/44 MAPK, p38 MAPK, and JNK. Cell spreading has been reported to play important roles in wound repair, tumor invasion, and metastasis. Therefore, catecholamines acting via the (alpha1)AR may modulate these physiological and pathological processes.

[Recurrence, metastasis and complications of stage I and II endometrial neoplasms treated by different therapeutic modalities]

OBJECTIVE

To make an approach to the relationship between recurrence, metastasis and complication of stage I and II endometrial carcinoma treated by 4 different therapeutic modalities.

METHODS

To compare the rates of recurrence, metastasis and complication in 4 treatment groups (surgery, full-dose preoperative intracavitary irradiation, non-full dose preoperative intracavitary irradiation and radiation alone).

RESULTS

Recurrence and metastasis in surgery, full-dose preoperative intracavitary irradiation, non full-dose preoperative intracavitary and radiotherapy alone groups were 19.8%, 8.1%, 22.2% and 34.6%, respectively. The recurrent rates of vaginal stump were 6.2%, 1.6%, 11.1% and 11.5%, respectively. The rates of proctitis and cystitis in full dose preoperative intracavitary irradiation group were 3.2% and 3.2%, 2.8 and 0.0% in non-full dose preoperative intracavitay irradiation group, and 0.0% and 3.8% in radiotherapy alone group.

CONCLUSIONS

The rates of recurrence and metastasis in full-dose preoperative intracavitary irradiation group were the lowest compared with other groups and incidence of complication was also low. This therapeutic method is the optimal choice for the treatment of endometrial carcinoma with stage I and II.

Neurogenesis and identification of developing layers in the visual cortex of the wallaby (Macropus eugenii)

Birthdates of the neurons that comprise the layers of the mature visual cortex in the wallaby (Macropus eugenii) have been determined with the aid of tritiated thymidine autoradiography. The laminar positions of cells, identified by their birthdates, have then been followed at early stages during development and compared with previously published data on the distribution of thalamocortical afferents and corticothalamic projecting cells (Sheng et al. [1991] J. Comp. Neurol. 307:17-38). Neurons are born in a deep to superficial sequence typical of other mammals. The loosely packed zone of cells, which develops at the base of the thin compact zone of cells at the superficial margin of the cortical plate early in development, was identified as being part of the cortical plate. Afferents did not wait below this zone but grew into the developing cortical layers immediately after the cells that form these layers began accumulating in the loosely packed zone, starting with layer 6 on postnatal day 22 (P22). The genesis of layer 4 did not begin until P32, and these cells reached the superficial cortical plate at P54 and entered the loosely packed zone by P65. Cells of layers 5 and 6 formed the initial projection to the thalamus. Despite the protracted development of the wallaby and the large discrepancy between the time of thalamic ingrowth and genesis of layer 4, there was no extended waiting period for afferents in the subplate.

FIMM, a database of functional molecular immunology

FIMM database (http://sdmc.krdl.org.sg:8080/fimm ) contains data relevant to functional molecular immunology, focusing on cellular immunology. It contains fully referenced data on protein antigens, major histocompatibility complex (MHC) molecules, MHC-associated peptides and relevant disease associations. FIMM has a set of search tools for extraction of information and results are presented as lists or as reports.

[Bcl-2 gene expression in endometrial carcinoma]

OBJECTIVE

To evaluate the relationship between bcl-2 gene and endometrial carcinoma.

METHODS

Immunohistochemical staining was performed on formalin-fixed paraffin-embedded tissue sections. A monoclonal antibody to the bcl-2 gene product was used, the signal was detected using a streptavidin-biotin complex with aminoethylcarbazole. There were 15 cases of endometrial atypical hyperplasia and 50 cases of endometrial carcinoma examined.

RESULTS

Bcl-2 expression was high in endometrial atypical hyperplasia, whereas bcl-2 expression was low in endometrial carcinoma. In endometrial carcinoma, with progression of clinical stage, decreased histologic grade and deepening of cancer invasion, the positive rate of bcl-2 expression was correspondingly decreased.

CONCLUSION

Bcl-2 plays a role in the genesis of endometrial carcinoma especially at the initial stage.

[The clinical evaluation of endometrial carcinoma following irradiation for cervical cancer]

OBJECTIVE

To study the characteristics and clinical features of endometrial carcinoma occurred after pelvic irradiation.

METHODS

Clinical data of 27 cases of endometrial carcinoma occurred after irradiation for cervical cancer were reviewed, estrogen receptor (ER) and progesterone receptor (PR) status were studied in 17 cases by immunohistochemistry.

RESULTS

The incidence of endometrial carcinoma occurred following pelvic irradiation was 0.19%. The mean age of patients was 63 year old. The mean incubation period from pelvic irradiation to diagnosis of the disease was 15.6 years. The proportion of advanced cases was 51.9% (14/27). The expression of ER and PR was very low (11.8%, 2/17). The original sites of 5 cases with stage I were in fundus or corner of the uterus, which received lower dose irradiation formerly. Operation was the best choice of treatment, 19 out of 27 cases received this modality. The survival rate of 3 and 5 year was 56.8%, 37.8%, respectively.

CONCLUSION

The incidence of endometrial carcinoma occurred following pelvic irradiation for cervical cancer was higher than that of cancer occurred spontaneously, the proportion of advanced cases was high, the expression of ER and PR was very low, operation was the mainly method of treatment. The prognosis was poorer than that of spontaneous disease.

[Effects of excessive zinc in fodder on brain development and abilities of learning and memory and their mechanisms in young rats]

OBJECTIVE

To study the effects of excessive zinc in fodder on brain development and abilities of learning and memory and to explore their mechanisms in young rats.

METHODS

Animal models with excessive zinc were established in young Wistar rats during their lactation period. Rats were divided into five groups, Groups ZE1 and ZE2 were fed with excessive zinc, Group AL was freely fed with Flanagna fomula fodder added with zinc sulfate, Group PF was matched pair of Group ZE2 and Group ZE2R was fed with fodder same as Group AL after weaning. Ultrastructure was observed with electron microscopy, their free amino acids, nitrous oxide and somatostatin were measured with neurobiochemical methods, and their abilities to learn and memorize were examined.

RESULTS

Weight of cerebrum and hippocampus in the rats reduced and zinc levels in their serum and hippocampus raised with the increase of zinc content in their fodder. Acute avoidance response (AAR) and movement in the young rats fed with excessive zinc in Groups ZE1 and ZE2 were obviously lower than in Groups AL and PF. AAR was significantly lower in Group ZE2R than that in Groups AL and PF, but significantly higher than that in Group ZE2. There was no significant difference in AAR between Groups PF and AL, but more movement was observed in them. Nitrous oxide in hippocampus raised and somatostatin decreased in Group ZE2, and total amount of excitatory and inhibitory amino acids in brain tissues raised, especially for glutamic acid. Neurones, gliocytes and organella in the CA1 region of hippocampus in the Group ZE2 showed degeneration, necrosis and rupture of synaptic bolus to varied extent.

CONCLUSION

Excessive zinc in fodder could significantly affect brain development and functions in young rats with multiple mechanisms.

[Ovarian metastasis from endometrial carcinoma: a report of 22 cases]

OBJECTIVE

To study the clinical characteristics of ovarian metastasis from endometrial carcinoma and its relation to pathologic features and prognosis.

METHODS

Twenty-two cases of histologically confirmed ovarian metastasis from endometrial carcinoma were retrospectively reviewed. Prognostic factors such as clinical staging, grade, myometrial infiltration, recurrence and treatment methods were analyzed.

RESULTS

The median age of this series was 50.6. Incidence of ovarian metastasis accounted for 4.4% in the same period. Ten out of 22 cases were in clinical stage I, 6 in stage II, and 6 in stage III. The treatment of choice was operation combined with radiotherapy. The overal 5- and 10-year survival rate was 61.5 and 55.9%, respectively.

CONCLUSION

Ovarian metastasis from endometrial carcinoma is associated with poor prognosis. Aggressive treatment after operation is required. For young patients in early stage of the disease, circumscript attitude should be taken as to preserve the ovary or not.

[Therapeutic modalities of endometrial carcinoma in stage I and II]

OBJECTIVE

To evaluate the effectiveness of different therapeutic modalities of endometrial carcinoma in stage I and stage II.

METHODS

From 1984 to 1992, 205 patients with endometrial carcinoma in stage I and stage II were treated in our hospital. The clinical and pathological data were analyzed retrospectively. There were 122 cases in stage I and 83 in stage II. According to therapeutic methods, patients could be divided into 4 groups. Group 1 (surgery group): 81 cases; Group 2 (full dose preoperative intracavitary afterloading irradiation, A point 45G y +/- 10%, F point 50 Gy +/- 10%): 62 cases; Group 3 (non-full dose preoperative intracavitary afterloading irradiation, doses at both point A and point F less than 1/2 of full dose mentioned above): 36 cases; Group 4 (radiotherapy alone): 26 cases. There were no significant differences in pathological type, differential grade, median age and operative methods among the 4 groups.

RESULTS

The 5-year survival rate of group 1 to group 4 was 83.1%, 96.5%, 84.8% and 62.5% respectively in stage I, and 82.0%, 90.9%, 51.4% and 62.7% respectively in stage II. The 5-year survival rate was significantly higher in group 2 (P < 0.05).

CONCLUSIONS

The results suggested that operation combined with full dose preoperative intracavitary afterloading irradiation provided the best therapeutic effect, whereas non-full dose preoperative intracavitary afterloading irradiation showed none of benefit.

Diagnosis of intrathoracic masses by transesophageal color Doppler echocardiography

OBJECTIVE

To evaluate the value of transesophageal color Doppler echocardiography in the diagnosis of intrathoracic masses.

METHODS

Twenty patients with intrathoracic masses were examined by transesophageal echocardiography (TEE), including 12 patients with central lung masses and 8 with mediastinal masses. The neoplasms were explored by two-dimensional realtime ultrasonography, Doppler color flow imaging (DCFI) and pulsed Doppler (PD). The results were compared with computed tomography (CT), operative and pathological examination findings.

RESULTS

We were able to identify the size, structure (solid or cystic), anatomic relationship, metastatic lymph nodes and venous carcinoembolus of the masses. Furthermore, the hemodynamic data in the vasculature inside the masses were detected.

CONCLUSIONS

As a new method, TEE with Doppler technique is not only valuable in differentiating malignant and benign neoplasms but also useful for preoperative evaluation of the mass resectability in patients with intrathoracic neoplasms.

[Evaluation of radiotherapy for state I ovarian carcinoma]

To investigate the role of radiotherapy for stage I epithelial ovarian carcinoma, the results in 91 patients treated from 1970-1989 were retrospectively analysed. There were 60 patients treated by operation combined with chemotherapy, 31 patients by operation combined with chemotherapy and radiotherapy. Patients in both groups were comparable with regard to age, clinical stage, histology grade, type of operation and chemotherapeutic regimen. The 5-year actuarial survival rate was 78.3% for those receiving additional radiotherapy and 72.4% for those without additional radiotherapy. The recurrence rate was 32.2% with a median recurrence time of 34 months in the former group while 60.6% and 18.6% months for the latter. Radiotherapy did not confer survival advantage in the treatment of stage I ovarian cancer, but it could decrease recurrence rate and delay onset of recurrence.

[Uterine papillary serous carcinoma and papillary endometrial carcinoma: analysis of clinical biological behaviors of 56 cases]

OBJECTIVE

To characterize the clinical biological behavior and the pathological morphology of uterine papillary serous carcinoma and papillary endometrial carcinoma.

METHODS

This is a retrospective analysis of 56 patients with papillary endometrial cancer treated at Cancer Hospital. Chinese Academy of Medical Sciences from January, 1981 to December, 1993. Of the 56 cases, 15 were uterine papillary serous carcinomas (UPSC), 41 papillary endometrial carcinomas (PEC). One hundred and sixty patients with endometrial adenocarcinoma (AC) were submitted as control group.

RESULTS

26.7% of UPSC, 14.6% of PEC and 5.6% of AC patients had stage III or IV by clinical examination (P < 0.05), whereas 53.3% of UPSC, 20.8% of PEC and 12.1% of AC patients has extrauterine disease at surgery (P < 0.01). Deep myometrial invasion occurred in 75.0% of UPSC, 41.7% of PEC, and 32.3% of AC patients (P < 0.01). An increasing gradient of 5 year survival rate (life table method) was observed from UPSC (45.7%) to PEC (61.9%) to AC (90.3%) in their early stage (stage I-II) (P < 0.01). Upper abdominal spread was a common finding in UPSC which had a high rate of persistent disease (46.2%). The pelvis was the predominant involving site in PEC with a high frequency of recurrence and metastasis (31.0%).

CONCLUSIONS

The presence of papillary features in endometrial carcinoma is an important prognostic indicator. The prognosis of PEC is better than UPSC, but worse than AC.

[Sarcoma of vulva: a clinical retrospective analysis of 10 cases]

OBJECTIVE

To study the characteristics of vulval sarcoma and its relationship between treatment methods and prognostic factors.

METHODS

10 cases of vulval sarcoma were retrospectively reviewed in this paper. Prognostic factors such as tumor volume, grade and treatment methods were analysed.

RESULTS

The age-incidence sarcoma of the vulva was 20 years younger than that of carcinoma of the vulva. The treatment of choice was operation combined with chemotherapy or radiotherapy. The effectiveness of chemotherapy or radiotherapy alone was not conclusive.

CONCLUSION

Primary treatment with thorough surgery is very important. The prognosis is related with tumor volume, grade and treatment methods.

Delineation of thyroid hormone-responsive sequences within a critical enhancer in the rat uncoupling protein gene

Uncoupling protein (UCP) is essential to brown adipose tissue (BAT) thermogenesis and, hence, to cold adaptation and energy balance. The sympathetic nervous system, via norepinephrine and cAMP, and thyroid hormone seem to be the major regulators of UCP expression. T3 potentiates the effect of norepinephrine and is essential for the adaptive response of this protein to cold. The goal of the present studies was to investigate whether T3 directly stimulates the transcription of the rat UCP gene, as suggested by in vivo results, and if so, to identify and characterize the sequences involved. We examined the gene sequence between 114 and -3623 by transient transfection analysis in JEG-3 and HIB-1B cells, a BAT-derived cell line. This 3.7-kilobase UCP insert makes the reporter gene responsive to cAMP (4-fold), T3 (4-fold), or both combined (12-fold). We identified an 82-basepair (bp) restriction fragment between -2317 and -2399, which we called thyroid hormone response sequence (THRS), that conferred T3 responsiveness to the UCP minimal promoter (4- to 12-fold) as well as to the thymidine kinase promoter (3- to 6-fold). T3 receptor bound to THRS in vitro, retarding its migration in electrophoretic mobility shift assays. Footprinting of THRS revealed two potential thyroid hormone response elements (TRE) separated by 27 bp: upTRE, -2391/-2376, 5'ACCCCTACTGAGGCAA; and dnTRE, -2348/-2334, 5'AGGGCAGCAAGGTCA. The mutation of these putative TREs caused loss of both T3 receptor binding and transactivation by T3. The analysis of the mutants also demonstrated that both TREs contribute in similar proportion to the T3 responsiveness of the UCP gene and that dnTRE is necessary for the potentiation of the cAMP effect by T3. Both TREs are located within a previously identified 212-bp enhancer element, flanked by sequences considered essential for BAT expression and norepinephrine responsiveness. Although they do not mediate thyroid hormone responsiveness, the sequences flanking THRS increase basal reporter expression and enhance the responses to T3. In conclusion, our results indicate that T3 can stimulate the transcription of the UCP gene and amplify the effect of cAMP acting directly on the gene. The presence of two functional TREs in a location critical to the control of the gene supports the importance of thyroid hormone for its expression and suggests the potential for interactions at the gene level that may explain the complexity of UCP regulation in vivo.