Free vibration analysis of all round clamped thin isotropic rectangular plate by Ritz Direct Variational Method

This paper developed polynomial comparison functions for the free vibration analysis of clamped thin rectangular plates using the Ritz Direct Variational Method. The polynomials were derived systematically from a predefined formula, which could generate any number of trial functions for any set of plate’s classical boundary conditions. The method was implemented by means of a Mathematica computer programme developed by the authors. The frequency parameters so obtained agreed excellently with those available in the literature. The numerical values of the frequency parameters increased with the aspect ratio irrespective of the mode considered. In addition, the study showed that the more the number of polynomial coordinate functions in the shape function, the better the accuracy of the results. The convergence study corroborated the fact that a one-term approximation yields sufficient accuracy. The convergence was best for square plates, even though acceptable percentages of convergence were obtained for the other side ratios.

[Umbilical Artery Doppler Study Role In The Monitoring And Obstetric Management Of High-Risk Pregnancies]

OBJECTIVE

to compare aspects of the diastolic component of umbilical artery flow with fetal fate parameters.

MATERIAL AND METHODS

this was a prospective, cross-sectional study at the Kaolack Regional Hospital over 6 months including patients with an at-risk pregnancy and a gestational age greater than 20 SA. The aspect of umbilical artery flow, umbilical artery IR and cerebro-placental index were studied.We compared the velocity data with the rates of fetal suffering, low birth weight and perinatal mortality. The statistical analysis was done with EPI info software version 7, Excel 2010 and SPSS 20.0 with a p-value of less than 5%.

RESULTS

46 patients were included with an average age of 24.54 years. The mean gestational age was 33.7 AS. The diastolic component of umbilical artery flow was null in 19.6%; reversed in 10.9%; decreased in 21.7% and normal in 47.8%. Confrontation with fetal fate parameters found a rate of 78.6% fetal suffering in the null or reversed diastolic components group compared to 34.4% in the non-zero diastolic components group. For low birth weight, this rate was 92.9% compared to 28.1%. The perinatal mortality rate was 64.2% compared to 12.5%.

CONCLUSION

The umbilical artery Doppler study plays a major role in the monitoring and obstetric management of high-risk pregnancies. Our results demonstrate the correlation between a diastolic component of the flow of the pathological umbilical artery and the adverse outcome of the pregnancy at risk.

Seasonal variation in spatial distributions of Anopheles gambiae in a Sahelian village: evidence for aestivation

Changes in spatial distribution of mosquitoes over time in a Sahelian village were studied to understand the sources of the mosquitoes during the dry season when no larval sites are found. At that time, the sources of Anopheles gambiae Giles may be local shelters used by aestivating mosquitoes or migrants from distant populations. The mosquito distribution was more aggregated during the dry season, when few houses had densities 7- to 24-fold higher than expected. The high-density houses during the dry season differed from those of the wet season. Most high-density houses during the dry season changed between years, yet their vicinity was rather stable. Scan statistics confirmed the presence of one or two adjacent hotspots in the dry season, usually found on one edge of the village. These hotspots shifted between the early and late dry season. During the wet season, the hotspots were relatively stable near the main larval site. The locations of the hotspots in the wet season and early and late dry season were similar between years. Season-specific, stable, and focal hotspots are inconsistent with the predictions based on the arrival of migrants from distant localities during the dry season, but are consistent with the predictions based on local shelters used by aestivating mosquitoes. Targeting hotspots in Sahelian villages for vector control may not be effective because the degree of aggregation is moderate, the hotspots are not easily predicted, and they are not the sources of the population. However, targeting the dry-season shelters may be highly cost-effective, once they can be identified and predicted.

Reproductive output of female Anopheles gambiae (Diptera: Culicidae): comparison of molecular forms

Knowledge of ecological differences between the molecular forms of Anopheles gambiae Giles (Diptera: Culicidae) might lead to understanding of their unique contribution to disease transmission, to better vector control, and to identification of the forces that have separated them. We compared female fecundity measured as egg batch size in relation to body size between the molecular forms in Mali and contrasted them with their sibling species, Anopheles arabiensis Patton. To determine whether eggs of different egg batches are of similar "quality," we compared the total protein content of first-stage larvae (L1s), collected < 2 h after hatching in deionized water. Egg batch size significantly varied between An. gambiae and An. arabiensis and between the molecular forms of An. gambiae (mean batch size was 186.3, 182.5, and 162.0 eggs in An. arabiensis and the M and the S molecular form of An. gambiae, respectively). After accommodating female body size, however, the difference in batch size was not significant. In the S molecular form, egg protein content was not correlated with egg batch size (r = -0.08, P > 0.7) nor with female body size (r = -0.18, P > 0.4), suggesting that females with more resources invest in more eggs rather than in higher quality eggs. The mean total protein in eggs of the M form (0.407 microg per L1) was 6% higher than that of the S form (0.384 microg per L1), indicating that the M form invests a greater portion of her resources into current (rather than future) reproduction. A greater investment per offspring coupled with larger egg batch size may reflect an adaptation of the M form to low productivity larval sites as independent evidence suggests.

Adjuvant cytotoxic and endocrine therapy in pre- and postmenopausal patients with breast cancer and one to nine infiltrated nodes: five-year results of the Hellenic Cooperative Oncology Group randomized HE 10/92 study

SUMMARY

The present randomized phase III trial was designed to detect a 15% benefit in relapse-free survival (RFS) or overall survival (OS) from the incorporation of adjuvant tamoxifen to the combination of CNF [cyclophosphamide, 500 mg/m2; mitoxantrone (Novantrone), 10 mg/m2; fluorouracil, 500 mg/m2 chemotherapy and ovarian ablation in premenopausal patients with node-positive breast cancer and conversely from the incorporation of CNF chemotherapy to adjuvant tamoxifen in node-positive postmenopausal patients. From April 1992 until March 1998, 456 patients with operable breast cancer and one to nine infiltrated axillary nodes entered the study. Premenopausal patients were treated with six cycles of CNF chemotherapy followed by ovarian ablation with monthly injections of triptoreline 3.75 mg for 1 year (Group A, 84 patients) or the same treatment followed by 5 years of tamoxifen (Group B, 92 patients). Postmenopausal patients received 5 years of tamoxifen (Group C, 145 patients) or 6 cycles of CNF followed by 5 years of tamoxifen (Group D, 135 patients). Adjuvant radiation was administered to all patients with partial mastectomy. After a median follow-up period of 5 years, 125 patients (27%) relapsed and 79 (17%) died. The 5-year actuarial RFS for premenopausal patients was 65% in Group A and 68% in Group B (p = 0.86) and for postmenopausal patients 70% in Group C and 67% in Group D (p = 0.36). Also, the respective OS rates were 77% and 80% (p = 0.68) for premenopausal and 84% and 78% (p = 0.10) for postmenopausal patients. Severe toxicities were infrequently seen, with the exception of leukopenia (18%), among the 311 patients treated with CNF. In conclusion, the present study failed to demonstrate a 15% difference in RFS in favor of node-positive premenopausal patients treated with an additional 5 years of tamoxifen after CNF adjuvant chemotherapy and ovarian ablation. Similarly, six cycles of CNF preceding 5 years of tamoxifen did not translate to a 15% RFS benefit in node-positive postmenopausal patients.

Correlation between morphology, immunohistochemistry and molecular pathology in hereditary and sporadic breast cancer cases

Breast cancer still represents a serious health problem and is currently the most frequent malignancy in the female population in developed countries. In Cyprus, there are 300 new cases annually. In the present study, histology, electron microscopy, immunohistochemistry, and Western blot analysis were used to investigate 100 cases of invasive breast carcinoma. In addition, mutation analysis for the BRCA1 gene was carried out in patient DNA from 26 families with multiple cases of breast/ovarian cancers. Of note are the results of molecular biology which show that there are no germline truncating mutations in the BRCA1 gene in these 26 Cypriot breast cancer families. Furthermore, Western blot analysis revealed the presence of multiple BRCA1 bands in homogenates of tumor and normal tissues, and immunoelectron microscopy showed the presence of nuclear staining for BRCA1 antibodies.

Weekly paclitaxel as first-line chemotherapy and trastuzumab in patients with advanced breast cancer. A Hellenic Cooperative Oncology Group phase II study

AIM

To evaluate the activity and acute toxicity of the combination of weekly paclitaxel as first-line chemotherapy and trastuzumab, in patients with HER-2/neu overexpressing advanced breast cancer (ABC).

BACKGROUND

Weekly paclitaxel has been shown to be a well tolerated treatment with considerable activity in patients with ABC. Clinical trials with transtuzumab, a humanized anti-p185 HER-2/neu monoclonal antibody have demonstrated that this agent produces objective responses in patients with ABC.

PATIENTS AND METHODS

From December 1998 to April 2000, 34 patients with HER-2/neu overexpressing ABC were treated with weekly paclitaxel; given by one-hour infusion at a dose of 90 mg/m2 immediately followed by trastuzumab, 4 mg/kg as a loading dose and 2 mg/kg i.v. given over 30 min, thereafter weekly for at least 12 weeks. Expression of HER-2/neu was determined by immunohistochemical analysis on fixed, paraffin-embedded tissues. Eligible patients were required to have > or = 25% stained tumor cells.

RESULTS

Thirty-three patients completed at least 12 weeks of combined treatment. After completion of the 12th week of treatment, four patients (12%) achieved complete and 17 (50%) partial response. Median duration of response was 11.6 months. More frequent side effects included anemia (56%). neutropenia (27%), peripheral neuropathy (78%), diarrhea (30%), alopecia (70%), arthralgias/myalgias (62%), fatigue (59%) and hypersensitivity reactions (62%). Median time to progression was nine months while median survival had not been reached

CONCLUSIONS

The combination of weekly paclitaxel and trastuzumab is a safe and active regimen for patients with HER-2/neu overexpressing ABC. Randomized phase III studies with this combination are warranted.

BRCA1 germline mutations in Cypriot breast cancer patients from 26 families with family history

Germline mutations in the BRCA1 gene are causative for a variable number of hereditary breast/ovarian cancers. The data presented in this study are based on genetic analysis of the BRCA1 gene in 49 DNA samples from breast cancer patients with a positive family history. A combination of manual direct DNA sequencing and SSCP analysis was used to screen the entire coding region of BRCA1. Overall 13 variants were detected which included 5 missense mutations, 3 polymorphisms and 5 intronic changes. Further genetic analysis of the 13 variants was carried out using 50 control DNA samples. Our results showed that 12 out of the 13 variants detected in the DNA of the patients group, were also present in the control group. It appears that the Greek Cypriot families studied so far have an unexpectebly low frequency of deleterious mutations in the BRCA1 gene. This is the first report on BRCA1 mutation analysis in Cyprus.

Immunohistochemical versus molecular detection of RAK antigens in breast cancer

RAK antigens p120, p42, and p25 exhibit molecular and immunological similarity to the proteins encoded by HIV-1 and are expressed by 95% of breast and gynecological cancer cases in women and prostate cancer cases in men. Binding of the monoclonal antibody (MAb) RAK-BrI to cancer RAK antigens has been found to be inhibited by a peptide derived from the variable loop V3 of HIV-1. Since MAb RAK-BrI has been developed against denatured froms of breast cancer proteins, and it binds to a short epitope, GRAF, this MAb does not recognize the native, three-dimensional structure of proteins. Subsequently Western blot, after electrophoretic separation in gels with SDS, has been used to detect these unique cancer markers. The current studies were focused on the immunohistochemical evaluation of the novel marker RAK. Serial sections, 5 microm thick, were cut from frozen or Formalin-fixed, paraffin-embedded tissue blocks and immunostained with MAb RAK-BrI. All of the 53 cases of breast cancer tested RAK positive and no differences were observed in the immunohistochemical staining of lobular and ductal carcinoma cases. In contrast, MAb RAK-BrI antigens were detected in only 3 of 15 cases of macroscopically normal breast removed during mastectomy for breast cancer. It is noteworthy that Western blots of breast samples from the same series demonstrated a high expression of three RAK antigens in 20/20 of invasive breast carcinomas, while there was only a very weak expression of RAK antigens in 2/7 of the macroscopically "normal" breast samples. Due to the suspected viral origin of RAK markers, immunohistochemical staining with MAb RAK-BrI might be a useful tool in the early detection of malignant changes occurring in breast tissues.

Prognostic variables in greek patients with stage II breast cancer: a Hellenic Cooperative Oncology Group study

The independent effects of several patient, tumor and treatment-related prognostic factors on relapse-free survival (RFS) and overall survival (OS) were assessed by Cox multivariate regression analysis in 988 Greek patients with stage II breast cancer. At a median follow-up time of 83 (range 3.3-131+) months and after the evaluation of all patients together, the number of positive axillary nodes (p < 0.0001), tumor size (p = 0.0024) and tumor grade (p = 0.0008) were identified as significant prognostic factors for RFS. Also, the number of positive nodes (p < 0.0001), tumor size (p = 0.0002) and ER status (p = 0.0001) were found to be significant for OS. These short-term prognostic variables are similar to those reported for this group of patients in other European countries and in the USA.

[Epidemiological notes: meningococcal meningitis of serogroup X in Niamey (Niger)]

From 19th February to 15th April 1990, 22 strains of meningococcus belonging to serogroup X have been identified by the Centre for Study and Research on meningitidis and Schistosomiases (CERMES) at Niamey (Niger). Serogroup X has been confirmed by the Centre Collaborating WHO of Reference and Training for Meningococci (CCOMSRFM) at Marseille (France). These strains have been isolated from cerebrospinal fluid of patients suffering from cerebrospinal meningitis and living in different neighbourhoods of Niamey. Apparition of cases of meningococcal meningitis with other serogroups than A implies identification of serogroup of meningococcus in intertropical Africa.