Inverse metal-assisted chemical etching of germanium with gold and hydrogen peroxide.

Metal-assisted chemical etching (MACE) is a flexible technique for texturing the surface of semiconductors. In this work, we study the spatial variation of the etch profile, the effect of angular orientation relative to the crystallographic planes, and the effect of doping type. We employ gold in direct contact with germanium as the metal catalyst, and dilute hydrogen peroxide solution as the chemical etchant. With this catalyst-etchant combination, we observe inverse-MACE, where the area directly under gold is not etched, but the neighboring, exposed germanium experiences enhanced etching. This enhancement in etching decays exponentially with the lateral distance from the gold structure. An empirical formula for the gold-enhanced etching depth as a function of lateral distance from the edge of the gold film is extracted from the experimentally measured etch profiles. The lateral range of enhanced etching is approximately 10-20µm and is independent of etchant concentration. At length scales beyond a few microns, the etching enhancement is independent of the orientation with respect to the germanium crystallographic planes. The etch rate as a function of etchant concentration follows a power law with exponent smaller than 1. The observed etch rates and profiles are independent of whether the germanium substrate is n-type, p-type, or nearly intrinsic.

Effects of perceptions and mentorship on pursuing a career in academic medicine in obstetrics and gynecology.

PURPOSE: To understand the perceptions of residents and Fellows in obstetrics and gynecology about the impacts of race or ethnicity, gender, and mentorship experiences on pursuing careers in academic medicine. METHOD: Two surveys were administered: one to a sample of 2,000 Fellows of the American College of Obstetricians and Gynecologists, and one to the 4,814 obstetrics and gynecology residents taking the 1998 in-training examination. The questionnaires asked about demographics, perceptions about careers in academic medicine, and residents' experiences with mentorship. RESULTS: Response rates were 96.8% for residents and 40.6% for FELLOWS: Of the residents, 26.1% indicated they would not consider a career in academic medicine. First-year women residents were more inclined to pursue careers in academic medicine than were first-year men (p =.042), but their interest declined during residency. Women residents (43%)-especially minorities-felt that men were mentored and recruited more for faculty positions, while men (38%) felt that women were mentored and recruited more. Fellows' reports of recruitment did not differ by gender. Most white residents did not perceive racial or ethnic bias in mentoring or recruiting, while most non-white residents did. Almost one third of non-white women residents felt that supervisors were more likely to condescend to women and minority individuals. CONCLUSIONS: It is likely that neither men nor women residents in obstetrics and gynecology receive adequate mentorship for careers in academic medicine. Perceptions of bias are a serious barrier to developing racial, ethnic, and gender diversity in leadership positions.

End of life care: history and the role of the obstetrician and gynaecologist.

In obstetrics and gynaecology we care for women who will die during pregnancy, for women who have fatal diseases such as autoimmune diseases or renal, liver, or cardiac failure where our care is tangential but critical to palliation, and for women dying with gynaecological malignancies. Understanding the history of the development of hospice and palliative care, as well as the ethical framework for these choices, may allow us to understand better the difficulties we face in our modern settings in making the choice to turn our goals from prolonging life to maximal comfort on the path to death. Obstetrician gynaecologists have a responsibility to be a voice of advocacy for maximal palliative care for not only the women they care for, but also for women worldwide because of their diminished social status and poverty.

Practical aspects of hospice care at home.

While much of hospice care, from a medical professional viewpoint, is concentrated on the physiology and pharmacology of maximal symptom management in hospital or at home, families and those caring for the day-to-day aspects of dying face different barriers to care. Achieving an environment that is both the safest and the most efficient for care at home is not often considered and the elements of achieving that environment are the focus of this chapter. What general equipment needs, what 'nursing' skills and what practical advice can we give to families and care-givers who care for dying patients at home? It is important that physicians understand the details of home care planning and needs so they can provide the best counsel for patients and their families as they make choices about terminal care.

A global overview of ethical issues in women's health.

The fundamental denial of basic human rights to reproductive choice, freedom from violence, and economic and educational development for women remains the major underpinning ethical issue in worldwide women's healthcare. The ability to choose when to have children, whether to have prenatal diagnosis or to make uncoerced choices at the end of life all hinge on the independence of each woman's ability to make choices about their own healthcare within the constraints of the health resources available to them. Technologic advances increase the complexity of assuring that the rights and best interest of the woman, the fetus or child, and society itself are balanced equitably in both the healthcare setting as well as the development of national or international policies and standards. The obstetrician/gynecologist, as an advocate for women's health worldwide, has an ethical obligation to assure human rights are extended to women and the obligation to assure that the care received is the best available.

Preventing cervical cancer.

The Pap smear has been the classic screening strategy for preventing cervical cancer for 50 years. The finding that infection with human papillomavirus is associated with an increased risk of cervical cancer has prompted the development of new strategies for cervical cancer screening and prevention. In their Policy Forum, Cain and Howett discuss the introduction of HPV testing, anti-HPV microbicidal agents and vaccination against HPV. They point out the benefits but also the potential for over and under treatment and the need for considerable improvements in public education.

A retrospective review of paclitaxel-associated gastrointestinal necrosis in patients with epithelial ovarian cancer.

Seven patients with gastrointestinal necrosis following paclitaxel chemotherapy are reported. Four of seven patients had platinum refractory disease, while 3/7 patients received primary paclitaxel therapy. Complications occurred 5 to 16 days following paclitaxel therapy. The most common clinical presentation was fever (7/7 patients), neutropenia (6/7 patients), and abdominal pain (6/7 patients). All seven patients developed gastrointestinal necrosis following the first cycle of paclitaxel chemotherapy. The exact mechanism by which this complication occurs is poorly understood. We postulate that gastrointestinal necrosis may be the result of a direct drug effect on the gastrointestinal epithelium and might involve a synergistic interaction between compromised bowel and paclitaxel-induced mitotic arrest. We observe that the incidence of gastrointestinal necrosis in patients with platinum refractory disease is 4 of 108 patients (3.7%). The incidence of this complication in patients receiving primary paclitaxel at our institution is 3 of approximately 128 patients (2.3%). Eighteen cases to date have been identified in the literature. A high index of suspicion of this complication should be considered for patients presenting with neutropenic fever and abdominal pain following paclitaxel chemotherapy.

Comparison of 1997 Medicare relative value units for gender-specific procedures: is Adam still worth more than Eve?

BACKGROUND: On January 1, 1992, Congress implemented a Medicare payment system based on relative value units (RVUs). The total RVU (which is made up of work, practice, and malpractice RVUs) is multiplied by a dollar conversion factor to set the reimbursement for all procedures covered by Medicare. In a previous study, we found that significant gender bias exists in Medicare reimbursement for female-specific services. Recently, HCFA approved increases (beginning January 1997) in the work RVU for many gynecologic procedures. This study was undertaken to compare work and total RVUs for gender-specific procedures effective January 1, 1997. METHODS: Using the May 1996 Federal Register, we compared work and total RVUs for 24 pairs of gender-specific procedures. The groups were matched so that the amount of work and level of difficulty would be similar, if not identical. We validated our selection of procedures for comparison by also evaluating the average time required to perform these procedures. RESULTS: Comparison of work RVUs for the 24 paired procedures revealed that in 19 cases (80%), male-specific procedures had a higher RVU; in 3 cases (12%), female-specific procedures were higher; and in 2 cases, there was no difference. On average, work RVUs were 49% higher for urologic procedures than for gynecologic procedures. Comparison of total RVUs revealed that in 20 cases (83%), urologic procedures had a higher total RVU and in 3 cases (12%), gynecologic procedures were higher. On average, male-specific surgeries are reimbursed at an amount which is 37% higher than that for female-specific surgeries. CONCLUSION: Recent increases in work RVUs for many gynecologic procedures have resulted in improved reimbursement. However, even with these improvements, significant gender bias still exists in the Medicare reimbursement of female-specific procedures. This gender bias is further magnified as more private insurance carriers use the system to set reimbursement.

Is Adam worth more than Eve? The financial impact of gender bias in the federal reimbursement of gynecological procedures.

PURPOSE: On January 1, 1992, Congress implemented a Medicare payment system based on relative value units (RVU). The RVU multiplied by a dollar conversion factor sets the reimbursement for all procedures covered by Medicare and many other private insurers. This study was undertaken to evaluate discrepancies in federal reimbursement for gender-specific procedures. METHODS: Using the December 1995 Federal Register and the regional Medicare conversion factor ($40.08/RVU), we compared the work RVU and total reimbursement of 24 groups of gender-specific surgical procedures. The groups were matched as carefully as possible so that the amount of work and level of difficulty would be similar, if not identical. Some examples of comparisons are as follows: biopsy of male vs female genitals, hysterectomy vs prostatectomy, staging for ovarian vs testicular cancer, and exenteration for cervical vs prostate cancer. RESULTS: In the 24 matched procedures, the male-specific procedures were reimbursed at a higher amount in 19 (79%) cases. The female-specific procedures were reimbursed at a higher amount in 3 (12%) cases (P = 0.004). There was no difference in reimbursement for two of the comparisons. Overall, we found that male-specific procedures are reimbursed at an amount which is 44% higher than female-specific procedures. Comparison of work RVU revealed that male-specific procedures were assigned higher values in 19 cases and, overall, male gender-related surgeries had work RVU that were 50% higher than female gender-related surgeries. CONCLUSION: There is significant gender bias against the Medicare reimbursement of female-specific services. This results in a lower net reimbursement for gynecologic procedures. In addition, since many private sector insurance carriers now use the resource-based relative value scale system, this gender bias is further potentiated.

Serum inhibin and disease status in women with ovarian granulosa cell tumors.

OBJECTIVE: To determine if immunoreactive inhibin assayed in serum from women with granulosa cell tumors correlated with tumor burden, reflected response to treatment, or predicted recurrent disease. STUDY DESIGN: Serum samples were collected following bilateral oophorectomy (BSO) with or without other indicated surgery in 15 patients with granulosa cell tumors. Inhibin radioimmunoassay (RIA-Inh) was performed on all samples and results were correlated with tumor burden, disease status, and treatment response. RESULTS: Fifteen patients had serum assayed for inhibin with levels ranging from 0 to 7470 U/liter. In 4 patients with measurable recurrent disease, inhibin levels correlated directly with tumor burden (r2 = 0.96). Four patients had serum drawn during clinical remission and in all 4 patients elevated inhibin levels predated recurrence by a median interval of 11.5 months (range 7-20). The remaining 7 were treated for primary disease and were in clinical remission with a median follow-up of 33 months (range 9-53). Four of these 7 patients were surgically staged: 2 were FIGO Stage I and inhibin levels fell to 0 U/liter; 2 patients had metastatic disease (Stage IIc and IIIa) and their inhibin levels were found to be elevated following complete resection. The remaining 3 were not surgically staged, and all had elevated inhibin levels while in clinical remission, suggesting occult disease. Of the 15 total patients, 1 who was treated with chemotherapy for recurrent disease was followed with serial inhibin levels. She showed a complete response to therapy with inhibin levels falling from 975 to 0 U/liter with 15 months follow-up. CONCLUSIONS: Serum inhibin levels reflect tumor burden and may be valuable in assessing response to chemotherapy or predicting recurrent disease in women with granulosa cell tumors who have had BSO. Serum inhibin level evaluation should be incorporated into large-group trials of therapy for granulosa cell tumors.

Phase II study of high-dose cisplatin, etoposide, and cyclophosphamide for refractory ovarian cancer.

OBJECTIVES: A phase II trial of high-dose cyclophosphamide, etoposide, and cisplatin was done. STUDY DESIGN: Forty-eight patients with progressive or persistent disease and previous cisplatin-based chemotherapy and no paclitaxel therapy were entered for treatment on the basis of two cycles of cyclophosphamide (4500 mg/m2), etoposide (750 mg/m2), and cisplatin (120 mg/m2). RESULT: Seventy-four cycles were delivered. Six patients died during treatment (12.5%). Of 28 with measurable disease, there was a 25% response rate and 32% had stable disease. Median time to recurrence and survival were significantly different for minimal versus bulky disease (p = 0.0089, p = 0.0008, log rank) and for platinum-sensitive versus platinum-resistant disease (p = 0.18, p = 0.0012, log-rank). The number of prior regimens was not correlated with time to progression or survival. CONCLUSION: This study shows little advantage for high-dose protocols except for patients with a response to platinating agents and minimal residual disease.

Clear cell carcinoma of the ovary: a distinct histologic type with poor prognosis and resistance to platinum-based chemotherapy in stage III disease.

Between 1982 and 1992, 24 women with Stage III clear cell ovarian cancer were identified from the tumor registry. Thirty-four women with Stage III papillary serous tumors treated between 1987 and 1989 were used as a comparison. All patients underwent cytoreductive surgery followed by conventional platinum-based chemotherapy. In the women with clear cell histology, nine (37.5%) had endometriosis in the surgical specimen compared with one (3%) in the papillary serous group (P = 0.002). Ten women (42%) with clear cell histology experienced a thromboembolic event during the course of treatment, compared to six (18%) in the papillary serous group (P = 0.05). In the group with clear cell histology, overall, 70% of women had progressive disease. Fifty-two percent experienced clinical progression while receiving platinum-based chemotherapy. In addition, four patients were found to have progressive disease at second-look laparotomy. Only two patients had a pathologic complete response. In the group with papillary serous histology, 29% overall had progressive disease while on chemotherapy (P = 0.005). The median survival for the women with clear cell histology was 12 months compared to 22 months for those with papillary serous (P = 0.02). For women with clear cell histology, univariate analysis was used to evaluate prognostic factors. Age less than 50 was a poor prognostic factor (P = 0.045). The presence of endometriosis, thromboembolic event, or optimal cytoreduction were not prognostic factors (P = 0.67, P = 0.34, P = 0.39). Patients with advanced clear cell ovarian cancer have a poor response to conventional platinum-based chemotherapy and overall prognosis is poor.