Photoluminescence properties of InAs nanowires grown on GaAs and Si substrates

We report the first photoluminescence (PL) characterization of InAs nanowires (NWs). The InAs NWs were grown on GaAs(111) B and Si(111) substrates using the Au-assisted molecular beam epitaxy (MBE) growth technique or metal-organic chemical vapor deposition (MOCVD). We compared the PL response of four samples grown under different conditions using MBE or MOCVD. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) patterns were utilized to determine the crystal structure and growth directions of the NWs to relate PL features to NW structural parameters. We observed mainly three PL peaks which were below, near and above InAs bandgaps, respectively. Temperature and excitation intensity dependence PL measurements were also performed to help elucidate the origins of the PL peaks of NWs. Of particular interest was a band-edge emission peak that was blue-shifted due to quantization effects of the InAs NWs, as confirmed by our calculation.

A case-controlled study of total laparoscopic radical hysterectomy with pelvic lymphadenectomy versus radical abdominal hysterectomy in a fellowship training program

To determine whether total laparoscopic radical hysterectomy (TLRH) is a feasible alternative to an abdominal radical hysterectomy (ARH) in a gynecologic oncology fellowship training program. We prospectively collected cases of all of the patients with cervical cancer treated with TLRH and pelvic lymphadenectomy by our division from 2000 to 2006. All of the patients from the TLRH group were matched 1:1 with the patients who had ARH during the same period based on stage, age, histological subtype, and nodal status. Thirty patients were treated with TLRH with a mean age of 48.3 years (range, 29–78 years). The mean pelvic lymph node count was 31 (range, 10–61) in the TLRH group versus 21.8 (range, 8–42) (P < 0.01) in the ARH group. Mean estimated blood loss was 200 cc (range, 100–600 cc) in the TLRH with no transfusions compared to 520 cc in the ARH group (P < 0.01), in which five patients required transfusions. Mean operating time was 318.5 min (range, 200–464 min) compared to 242.5 min in the ARH group (P < 0.01), and mean hospital stay was 3.8 days (range, 2–11 days) compared to 5.6 days in the ARH group (P < 0.01). All TLRH cases were completed laparoscopically. All patients in the TLRH group are disease free at the time of this report. In conclusion, it is feasible to incorporate TLRH training into the surgical curriculum of gynecologic oncology fellows without increasing perioperative morbidity. Standardization of TLRH technique and consistent guidance by experienced faculty is imperative.

Immunohistochemical characterization of cancer antigen in uterine cancers

The pattern of cancer antigen (CA-125) expression by immunohistochemistry (IHC) was investigated in malignant and nonneoplastic endometrium in endometrial carcinoma. Ninety cases of primary uterine carcinomas (65 endometrioid [EM] carcinoma, 15 serous papillary [SP] carcinoma, 6 carcinosarcomas [malignant mixed müllerian tumors], and 4 clear cell carcinoma [CC]) and adjacent atrophic and/or hyperplastic endometrium were analyzed by IHC for CA-125 expression. The percentage and intensity of luminal, apical, basal, and diffuse cytoplasmic immunostaining of epithelial cells were categorized on a scale of 0-4. The immunoreaction score (IRS score) was calculated and correlated with the grade and stage of carcinoma according to the histologic type. CA-125 expression (3-4/4) was localized in apical borders of grade 1 and grade 2 EM carcinoma and was weak or negative (0-1/4) in grade 3 EM. Mucinous differentiation in EM was associated with intense luminal and apical staining. Squamous areas and stroma showed no staining at all. SP carcinoma and endometrial intraepithelial carcinoma showed much higher mean IRS score than EM. In malignant mixed müllerian tumors (MMMT), the epithelial component stained as above according to the type of epithelial cell differentiation of the neoplastic cells. Benign proliferative glands showed moderate apical luminal, basal, and cytoplasmic staining. Intense diffuse staining was observed in atypical complex hyperplasia. Different patterns of CA-125 immunostaining were observed in normal, hyperplastic, and neoplastic endometrium. IRS score correlated with the grade but not with the stage of EM carcinoma. The intense different staining pattern of endometrium with atypical complex hyperplasia suggests that CA-125 may be a useful diagnostic aid.

Effective palliative radiation therapy in advanced and recurrent ovarian carcinoma

PURPOSE

To retrospectively review our experience using radiation therapy as a palliative treatment in ovarian carcinoma.

METHODS AND MATERIALS

Eighty patients who received radiation therapy for ovarian carcinoma between 1983 and 1998 were reviewed. The indications for radiation therapy, radiation therapy techniques, details, tolerance, and response were recorded. A complete response required complete resolution of the patient's symptoms, radiographic findings, palpable mass, or CA-125 level. A partial response required at least 50% resolution of these parameters. The actuarial survival rates from initial diagnosis and from the completion of radiation therapy were calculated.

RESULTS

The median age of the patients was 67 years (range 26 to 90 years). A median of one laparotomy was performed before irradiation. Zero to 20 cycles of a platinum-based chemotherapy regimen were delivered before irradiation (median = 6 cycles). The reasons for palliative treatment were: pain (n = 22), mass (n = 23), obstruction of ureter, rectum, esophagus, or stomach (n = 12), a positive second-look laparotomy (n = 9), ascites (n = 8), vaginal bleeding (n = 6), rectal bleeding (n = 1), lymphedema (n = 3), skin involvement (n = 1), or brain metastases with symptoms (n = 11). Some patients received treatment for more than one indication. Treatment was directed to the abdomen or pelvis in 64 patients, to the brain in 11, and to other sites in 5. The overall response rate was 73%. Twenty-eight percent of the patients experienced a complete response of their symptoms, palpable mass, and/or CA-125 level. Forty-five percent had a partial response. Only 11% suffered progressive disease during therapy that required discontinuation of the treatment. Sixteen percent had stable disease. The duration of the responses and stable disease lasted until death except in 10 patients who experienced recurrence of their symptoms between 1 and 21 months (median = 9 months). The 1-, 2-, 3-, and 5-year actuarial survival rates from diagnosis were 89%, 73%, 42%, and 33%, respectively. The survival rates calculated from the completion of radiotherapy were 39%, 27%, 13%, and 10%, respectively. Five percent of patients experienced Grade 3 diarrhea, vomiting, myelosuppression, or fatigue. Fourteen percent of patients experienced Grade 1 or 2 diarrhea, 19% experienced Grade 1 or 2 nausea and vomiting, and 11% had Grade 1 or 2 myelosuppression.

CONCLUSIONS

In this series of radiation therapy for advanced ovarian carcinoma, the response, survival, and tolerance rates compare favorably to those reported for current second- and third-line chemotherapy regimens. Cooperative groups should consider evaluating prospectively the use of radiation therapy before nonplatinum and/or nonpaclitaxel chemotherapy in these patients.

Vaginal Reconstruction With a Rectus Abdominis Musculoperitoneal Flap

In more than 300 clinical cases, the authors have observed and documented the presence of a branch of the deep inferior epigastric artery that penetrates the posterior rectus sheath near the umbilicus. Their cadaveric anatomic and animal injection studies confirm the vascularity of the peritoneum via the deep inferior epigastric artery. They report 2 patients treated with a new technique of vaginal reconstruction using a thin, pliable flap with a peritoneal-lined rectus abdominis muscle based on the deep inferior epigastric vessels.

Genetic epidemiology of type 1 diabetes mellitus in Taiwan

Some environmental and genetic factors play important roles in etiopathogenesis of type 1 or insulin-dependent diabetes mellitus (IDDM). HLA genes, the IDDM1 locus located the human chromosome 6, were found to be associated with insulin-dependent diabetes mellitus. However, the incidence of IDDM varied greatly among various populations. To evaluate the pathogenetic factors contributing to the development of IDDM in Taiwan, HLA typing was performed in a group of IDDM unrelated individuals and IDDM pedigrees along with the normal controls from the northern Taiwan. DNA genotypes of class II HLA were done by polymerase-chain-reaction based oligotyping techniques. We confirmed that class II HLA genes were significantly associated with IDDM in Taiwan. To study detailed molecular structure of class II HLA molecules and disease association, we examined several amino acid residues on DQalpha and DQbeta chains and the molecular mechanisms to explain the heterozygotic effect of the DR3/DR4 and DR3/DR9 in the Chinese population. Linkage analysis in our pedigrees confirmed the association between HLA and IDDM in population association studies. Among the several class II alleles, a closer segregation of HLA-DQB1*0401 to the affected persons might suggest that HLA-DQB1*0401 itself or an allele closely linked to the DQB1 locus was the IDDM-predisposing allele in Taiwanese. For IDDM2 (INS) region, association with IDDM was not found due to that more than 90% of the population carried class I alleles. In our collection of IDDM, we found few cases (2.4%) carried mitochondrial DNA mutation. Our studies in Taiwanese confirm a multigenetic nature for IDDM.

SpinThin, a simple, inexpensive technique for preparation of thin-layer cervical cytology from liquid-based specimens: data on 791 cases

BACKGROUND

Acceptance of liquid-based fixatives for cervical cytology has been limited by the more complex slide-preparation procedures, increased cost, and reports that increased sensitivity has been based largely on comparison with conventional cytology without histologic correlation. Here the authors describe and evaluate a technically simple and relatively inexpensive method (which they call SpinThin) for preparing Cytospin (Shandon Inc., Pittsburgh, PA) cervical cytology slides from samples in liquid fixative using a modified electric toothbrush holder to put the cells in suspension. Results are compared with conventional cytology and histologic biopsy.

METHODS

A total of 791 cervical cytology specimens from 2 patient groups at high risk of uterine cervical neoplasia were entered into this study, and a spatula and cytobrush (174 specimens) or cytobroom (617 specimens) were used to collect conventional smears. The collection device with remaining cellular sample was placed in an alcohol-based fixative solution; the cells were put into suspension by a brief burst of vibration using a modified electric toothbrush holder, then cytocentrifuged on a slide and stained with the Papanicolaou technique.

RESULTS

Specimen adequacy in SpinThin slides was better than that of conventional cytology smears. However, the prevalence of dysplasia, including atypical squamous cells of undetermined significance (ASCUS-D), in conventional smears and SpinThin slides was the same--27% and 25%, respectively--and excluding ASCUS-D, it was 20% in both. The prevalence of neoplasia (low or high grade squamous intraepithelial lesion, or carcinoma) histologically was 31% in the 647 cases biopsied, and agreement with histology was similar for SpinThin and conventional smears.

CONCLUSIONS

Using a simple and relatively inexpensive new technique (Spin-Thin), slides prepared from fluid-based cervical cytology specimens obtained with the cytobrush or cytobroom correlated very well with the corresponding conventional smears within major diagnostic categories, and both correlated well with histology.