Preliminary safety and efficacy results of a phase II study of oxaliplatin, docetaxel, and bevacizumab as first-line therapy of advanced cancer of the ovary, peritoneum, and fallopian tube

5518

Background: Objectives: Determine safety and estimate efficacy of a novel taxane/platinum chemotherapy (CTX) doublet in conjunction with bevacizumab, as first-line treatment of advanced cancer of the ovary, peritoneum or fallopian tube (FT), after initial debulking surgery. Methods: Treatment: 6 cycles of oxaliplatin (O) (85 mg/m2), docetaxel (D) (75 mg/m2) and bevacizumab (B) (15 mg/kg) Q3W, followed by maintenance B (15 mg/kg Q3W) to complete one year of therapy. Pts were treated until disease progression, unacceptable toxicity, prolonged treatment delay, death, or refusal to continue on study. The primary efficacy endpoint is PFS at 12 months. Results: As of 30 Nov 06, 59 pts (median age 58) were enrolled. Primary sites of disease included 47 ovary, 7 peritoneum, 4 FT. Tumors were mostly poorly differentiated (70%) with a serous adenocarcinoma initial pathology type (81%). Most pts were stage IIIC (40) or IV (17). 64% of pts. were optimally debulked. GOG PS was 0–1 in 56 pts. 58 pts were treated with at least one cycle of CTX. 22 pts. completed six cycles of CTX + B; 14 of these have begun B maintenance Rx. Safety data in available on a total of 283 patient-cycles. Of the 57 pts. with adverse event (AE) data available, 31 (54%) reported at least one grade 3–4 AE, 9 (16%) at least one serious AE (SAE), 54 at least one AE related to CTX (O or D), and 45 reported at least one AE related to B. There have been 8 SAEs related to CTX (O or D): febrile neutropenia (FN) (2), chest pain (1), dehydration (1), lymphopenia (1), neutropenia (1), peripheral sensory neuropathy (PSN) (1), palpitations (1). There have been 7 SAEs related to B: chest pain, colonic fistula, dehydration, FN, palpitations, PSN, vertigo (1 each). There were no B-associated colonic perforations. Of the 59 subjects, 31 (53%) had measurable disease at baseline. One of 31 patients has confirmed progression of disease. Conclusions: This preliminary data supports feasibility of this novel regimen, with an acceptable safety profile. As of December 2006, 75 patients have been enrolled. Updated safety and preliminary efficacy (RR) data will be presented.

No significant financial relationships to disclose.

Phase II study of nab-paclitaxel plus carboplatin in patients with recurrent platinum-sensitive ovarian or primary peritoneal cancer

15033

Background: This open-label, non-randomized study was designed to determine the efficacy and safety of nab-paclitaxel (a 130-nm albumin-bound particle form of paclitaxel) plus carboplatin in patients with metastatic ovarian or primary peritoneal carcinoma following platinum-based chemotherapy. Methods: Eligible patients had to have either measurable disease (based on RECIST criteria) or pretreatment CA-125 levels ≥2 times the upper limit of normal in the absence of measurable disease. Patients also had to have good performance status, adequate hepatic/renal function, peripheral neuropathy ≤ grade 1, and life expectancy ≥6 months. Patients may have received prior chemotherapy for ovarian cancer, including taxane-containing regimens, provided the treatment was completed at least 6 months before enrollment. nab-Paclitaxel 100 mg/m2 was administered IV over 30 minutes on days 1, 8, and 15 every 28 days. Carboplatin AUC6 was administered IV over 1−2 hours on day 1 every 28 days. Treatment continued for 6 cycles (or longer in the absence of unacceptable toxicity). Planned sample size was 43 patients (39 evaluable). Efficacy was determined by changes in tumor size for patients with measurable disease or changes in CA-125 levels for those with non-measurable disease. Results: To date, 10 patients have been enrolled, 2 of whom completed 2 treatment cycles; both patients had a 50% reduction in their disease (partial response). One patient had grade 4 neutropenia; grade 3 hematologic events were neutropenia (2 patients), thrombocytopenia (3), and anemia (1). Severe headache and severe nausea were reported for 2 patients each; all 4 events required medication. Conclusions: Preliminary results suggest that nab-paclitaxel 100 mg/m2 plus carboplatin AUC6 will have antitumor activity in patients with recurrent platinum-sensitive ovarian or primary peritoneal cancer and that treatment appears to be well tolerated. Updated response and toxicity data from this study will be presented.

No significant financial relationships to disclose.

Equal care ensures equal survival for African-American women with cervical carcinoma

BACKGROUND

[corrected] It was the purpose of this study to investigate whether race is an independent prognostic factor in the survival of patients with cervical carcinoma in a health care system with minimal racial bias, and few barriers to access to care.

METHODS

Records for patients with a diagnosis of invasive cervical carcinoma from 1988 to 1999 were obtained from the Automated Central Tumor Registry for the United States Military Health Care System. Clinical data including race, age at diagnosis, histology, grade, stage, socioeconomic status, treatment modality, and survival also were obtained. Survival analysis was performed with Kaplan-Meier survival curves.

RESULTS

One thousand five hundred fifty-three patients were obtained for review. Sixty-five percent of patients were Caucasian, and 35% were minorities. Of the minorities, 29% were African Americans (AAs). Mean age of diagnosis was similar among AAs and Caucasians, 44 and 42 years, respectively. There was no statistically significant difference between the distribution of age, stage, grade, or histology between Caucasians and AAs. Forty-six percent of patients were treated with surgery and 56% with radiation therapy, with no difference in type of treatment between the Caucasian and AA groups. Five- and 10-year survival rates for Caucasians and AAs were 75%, and 76%, and 64% 65% (P = 0.59), respectively.

CONCLUSIONS

In an equal access, unbiased, nonracial environment, race is not an independent predictor of survival for patients with cervical carcinoma. This study has shown, for the first time to the authors' knowledge, that when they receive equal treatment for cervical carcinoma, AA women's survival can approach that of their nonminority counterparts (75% at 10 years).

Videoteleconferencing for administration of a multisite obstetrics and gynecology core clerkship

Recent changes and trends in health care delivery have required medical schools to use multiple sites to obtain adequate patient exposure for their students. Decentralization of clinical undergraduate medical education may lead to a lack of continuity in curricula, evaluation, and feedback. We describe the use of interactive videoteleconferencing as a tool to link and improve a multi-site undergraduate core clerkship in obstetrics and gynecology. The Uniformed Services University of the Health Sciences, Bethesda, Maryland, currently utilizes five geographically separate sites for its 6-week core clerkship in obstetrics and gynecology. The site coordinators, clerkship director, and administrative personnel from the parent institution meet approximately 3 weeks after the completion of each core clerkship for live, real-time, and interactive broadcast to complete student evaluations, review curricula, and discuss problems with current students and other pertinent educational issues. Videoteleconferencing provides a mechanism to ensure consistency in curriculum and student evaluations and provides administrative support to distant sites. Furthermore, it enables site coordinators to keep the clerkship director abreast of students and clerkship issues.

A descriptive evaluation with follow-up of the clinical significance of atypical immature squamous metaplasia of the cervix

OBJECTIVES

We set out to determine the clinical significance of atypical immature squamous metaplasia (AIM).

METHODS

We performed in a military, hospital-based colposcopy clinic a descriptive, retrospective review of patients who had a diagnosis of AIM. Patients were examined at 3- to 4-month intervals for at least 1 year after a diagnosis of AIM was established. A gynecological pathologist reviewed all histological and cytological specimens. Initial histological or cytological specimens were tested for the presence of HPV DNA using in situ hybridization.

RESULTS

High-risk HPV DNA types 16 or 18 were detected in 3% of patients with AIM. Concurrent cervical intraepithelial neoplasia 3 (CIN3) was noted in 3% of patients with AIM. One-third of patients with initially diagnosed AIM had complete resolution of this lesion after 1 year of follow-up.

CONCLUSIONS

This descriptive, retrospective review shows that AIM does not appear to be associated with high-risk HPV DNA or with CIN3. In this limited study, a concurrent diagnosis of AIM likely does not influence the 1-year behavior of CIN. The degree of CIN should dictate treatment recommendations. A larger prospective trial is needed.

Effect of residency program merger on undergraduate medical student education in obstetrics and gynecology

OBJECTIVE

To evaluate the effect of residency program merger on third-year medical student clerkships using student evaluations of their experiences and standardized subject examination scores.

METHODS

End-of-clerkship ratings from student evaluations and National Board of Medical Examiners standardized subject examination scores in obstetrics and gynecology were used from clerkship sites where three separate military residency programs in obstetrics and gynecology recently merged into two new programs. Mean student evaluation scores and subject examination scores for the year preceding and the year following the merger were compared.

RESULTS

The mean differences in medical student evaluation scores before and after merger of the residency programs were 0.1 (Mann-Whitney rank sum, P = .1), -0.1 (Mann-Whitney rank sum, P = .8), and 0.2 (Mann-Whitney rank sum, P = .3). The mean differences for subject examination scores before and after merger of the residency programs were -3.5 (95% confidence interval [CI] -33.2, 26.2; paired t test), -30.1 (95% CI -58.9, -1.4; paired t test), and -35.3 (95% CI -74.8, 4.3; paired t test).

CONCLUSION

Merger of residency programs in obstetrics and gynecology does not appear to have a deleterious effect on medical students' satisfaction with the clerkship or their performance on standardized subject examinations at our institution.

Primary peritoneal psammocarcinoma: A case presenting with an upper abdominal mass and elevated CA-125

Primary peritoneal serous adenocarcinoma with predominating psammoma bodies, psammocarcinoma, is a very rare tumor with only seven cases documented in the English literature. Pathological classification of this entity was established in 1990 and clinical behavior of this tumor is uncertain. Based on limited data these tumors appear to behave similarly to low malignant potential tumors of the ovary. This case describes a 59-year-old woman who underwent exploratory laparotomy for a large upper abdominal cystic mass. Findings included a large tumor mass involving the gastrocolic omentum and dense small bowel adhesions. The patient had normal ovaries and was debulked to no macroscopic disease. Final pathologic diagnosis confirmed a stage IIIC primary peritoneal psammocarcinoma. The patient has received no adjunctive therapy and is without evidence of disease 2 years after surgery. Primary peritoneal psammocarcinoma is a neoplasm which can mimic serous adenocarcinoma of the ovary. In contrast, primary peritoneal psammocarcinoma appears to behave in an indolent fashion. Primary surgical debulking should be attempted, while the utility of postoperative chemotherapy remains unknown.

Development and use of military-unique standardized gynecology patients in military undergraduate medical education

Performance-based testing using standardized patients is becoming increasingly popular as a means to assess the clinical competence of medical students. Medical students entering postgraduate training in military treatment facilities have the additional responsibility of military readiness. The increasing number of women in the active armed forces and the diverse missions encountered by the military today necessitate inclusion of military-unique standardized gynecologic patients and scenarios into curricula. We developed a military-unique standardized gynecology patient and scenario and an objective structured clinical examination to evaluate medical students' skills in data gathering and synthesis, development of differential diagnoses, problem solving, and working through military-unique issues of the patient scenario. Integration of an objective structured clinical examination of military-unique gynecology standardized patient scenarios into the obstetrics and gynecology curriculum at the Uniformed Services University of the Health Sciences can lead to successful assessment of student clinical skills and provide a means of ongoing military readiness training.

A survey of military residencies regarding 4th-year medical school clerkships

OBJECTIVE

To determine the value of 4th-year medical student clerkships assessed by military obstetric and gynecologic program directors and residents.

METHODS

A questionnaire was sent to all Department of Defense obstetric and gynecologic residency program directors and residents. All of the program directors and 124 of 194 (64%) residents responded, reporting the value of 4th-year medical student clerkships for students entering their programs. Descriptive statistics are reported.

RESULTS

Primary care clerkships were valued most highly by program directors who valued obstetric and gynecologic clerkships at their program sites or audition electives higher than those done at other sites. Residents most highly valued obstetric and gynecologic and intensive care clerkships. Most surgical subspecialties were believed to be of minimal or no value.

CONCLUSION

For students entering their programs, military program directors placed the highest value on primary care clerkships. Program directors also highly valued obstetric and gynecologic clerkships at their programs, whereas residents considered obstetric and gynecologic and intensive care clerkships to be most helpful.

Development and use of military-unique standardized gynecology patients for military residents in obstetrics and gynecology training programs

Focused military curricula and readiness training are often inadequate for military resident physicians. We developed a standardized gynecologic military-unique patient scenario and examination to assess obstetrics and gynecology residents' clinical and operational problem-solving abilities. Integration of military-unique gynecologic standardized patients, clinical scenarios, and objective structured clinical examinations into obstetrics and gynecology curricula is a novel approach for realistic medical readiness training for resident physicians. This tool can become a cornerstone in the ongoing development of needed military-unique curricula.

Prospects for human papillomavirus vaccine development

This review concentrates on recent advances in human papillomavirus vaccine development. Strategies for prophylactic HPV subunit vaccines utilizing recombinantly synthesized, immunogenic virus-like particles are discussed. Therapeutic strategies focusing on the induction of cell-mediated immunity and gene manipulation for the treatment of established HPV-associated disease are also reviewed.

Prospects for human papillomavirus vaccine development: emerging HPV vaccines

This review concentrates on recent advances in human papillomavirus vaccine development. Strategies for prophylactic HPV subunit vaccines utilizing recombinantly synthesized, immunogenic virus-like particles are discussed. Therapeutic strategies focusing on the induction of cell-mediated immunity and gene manipulation for the treatment of established HPV-associated disease are also reviewed.

Villoglandular adenocarcinoma of the cervix: a report of three cases and review of the literature

Villoglandular adenocarcinoma of the cervix is a distinct histologic type of cervical cancer. Fewer than 60 cases have been reported in the literature. Previous reports suggest that, due to the highly favorable prognosis of this rare histologic type of cervical cancer, conservative surgical therapy with cervical conization or extrafascial hysterectomy alone may be undertaken. In this series, three cases of villoglandular adenocarcinoma of the cervix are described. Preoperatively in each case, the cancer was confined to the cervix and histologic well-differentiated villoglandular adenocarcinoma of the cervix was confirmed. Extended hysterectomy was performed in all cases. In one case, residual invasive endocervical adenocarcinoma was noted. Careful review of the histologic characteristics of these tumors is needed when deciding if these patients can be managed with conservative therapy.

The occurrence of endometrial adenocarcinoma in a patient with basal cell nevus syndrome

Basal cell nevus syndrome is rare multisystem disorder. Its genital implications in female patients is thought to be limited to ovarian fibroma. This article describes endometrial adenocarcinoma in association with basal cell nevus syndrome in a 37-year-old female with multiple basal cell carcinomas, mandibular and maxillary bone cysts, right ovarian fibroma, and scoliosis. Histopathologic examination of her endometrial biopsy, performed for irregular uterine bleeding, revealed endometrial hyperplasia. Her bleeding failed to respond to progestin therapy, and a repeat endometrial biopsy revealed a well differentiated endometrial adenocarcinoma. Health-care providers are encouraged to refer these patients to gynecologists. Regular gynecologic examination as well as appropriate evaluation of abnormal menstrual bleeding should be emphasized.

Recurrent granulosa cell tumor of the ovary 37 years after initial diagnosis: a case report and review of the literature

Granulosa cell tumors of the ovary (GCTs) are uncommon neoplasms that are characterized by late recurrence and high survival rates. A case of recurrent GCT presenting 37 years after initial diagnosis is reported with a review of the literature. This case illustrates an example of a very late recurrence and emphasizes the importance of the extended follow-up required for these patients.

Prospects for a vaccine against human papillomavirus

OBJECTIVE

To summarize existing data regarding the feasibility of developing strategies for prophylactic and therapeutic vaccination against human papillomavirus (HPV) infection.

DATA SOURCES

We used the Medline data base and reference lists of articles to identify English-language papers that evaluate strategies for prophylactic and therapeutic vaccination against HPV infection.

METHODS OF STUDY SELECTION

Our search uncovered several reports of systems that produce recombinant HPV major capsid proteins as antigens for biochemical, molecular, and immunologic studies and investigations that evaluate cell-mediated immune responses to HPV-induced, tumor-associated peptides.

DATA EXTRACTION AND SYNTHESIS

Recombinant HPV major capsid proteins, which self-assemble into virus-like particles, are produced in quantity, mimic the conformation of native virions, react with neutralizing antibodies, and are type-specific. Human papillomavirus early viral peptides induce cytotoxic T lymphocyte responses that retard tumor progression and protect against tumor development after challenge in animal models.

CONCLUSIONS

Recombinant papillomavirus virus-like particles are highly antigenic, protective in animal models, lack potentially carcinogenic viral DNA, and are, therefore, ideal candidates for a prophylactic vaccine against HPV infection. Immunization with HPV tumor peptides may be beneficial in tumor prevention, regression, and rejection. Vaccines against HPV infection can be important in reducing the incidence of cervical dysplasia and carcinoma worldwide, particularly in developing countries.

Human papillomaviruses: their clinical significance in the management of cervical carcinoma

Studies have shown a strong association between certain human papillomaviruses and the development of cervical carcinoma and its precursor lesions. The oncogenic potential of papillomaviruses has been clearly demonstrated in both laboratory animals and cultured cells. Recent advances in our understanding of viral pathogenesis have provided insights into the natural history of papillomavirus infection and subsequent development of neoplasia. A more thorough understanding of the molecular mechanisms responsible for viral oncogenesis will facilitate the development of novel preventive and therapeutic strategies to prevent and treat papillomavirus-associated cervical neoplasias. Strategies under current investigation are focusing on the induction of effective humoral and cell-mediated immunity, the expression of HPV gene products, and cofactors that interact with HPV gene products to affect cell transformation. As a result of these investigative efforts, prophylactic HPV capsid vaccines and other gene therapies may soon become clinically available.

Spontaneous preoperative internal jugular and subclavian vein thrombosis associated with an early-stage synchronous ovarian/endometrial malignancy

A case of preoperative spontaneous internal jugular/subclavian vein thrombosis documented with magnetic resonance imaging associated with a synchronous stage II ovarian/stage I endometrial malignancy is presented. This unusual deep venous thrombosis site is classically associated with trauma, infection, head and neck malignancies, or central venous catheterization and is rarely associated with distant malignancies. Neck pain and swelling in a gynecologic oncology patient should prompt consideration of this diagnosis.

Role of conformational epitopes expressed by human papillomavirus major capsid proteins in the serologic detection of infection and prophylactic vaccination

Human papillomaviruses (HPVs) cause a variety of cutaneous warts, mucosal condylomata, and dysplasias and are etiologic in cervical cancer. Papillomavirus (PV) conformational epitopes on the surface of virions are type-specific and are the target of neutralizing antibodies. In this study, we describe two methods of in vitro expression of HPV major capsid (L1) proteins which mimicked conformational epitopes and demonstrate their type specificity and ability to react with neutralizing and/or conformation-dependent antibodies. The L1 open reading frames (ORFs) for HPV-1, 6, 11, and 16 were molecularly cloned into a SV 40 expression vector and the encoded gene products were expressed in mammalian (cos) cells. Similarly, the L1 ORFs for HPV-6, 11, 16, and 18 were molecularly cloned into recombinant baculovirus and the encoded gene products were expressed in insect (SF9) cells. The expressed L1 proteins reacted by immunofluorescence and immunoprecipitation with polyclonal and monoclonal antibodies generated against their corresponding native virions and by Western blotting with antibodies that recognized nonconformational epitopes of denatured virions. The recombinant L1 proteins expressed conformational epitopes in both cos and Sf9 cells that were type-specific and displayed neutralizing epitopes. The ability to express, purify, and qualitate the reactivity of recombinant L1 proteins will now permit the serologic analysis of host response to HPV infection and the development of prophylactic PV subunit vaccines.

The expressed L1 proteins of HPV-1, HPV-6, and HPV-11 display type-specific epitopes with native conformation and reactivity with neutralizing and nonneutralizing antibodies

Previous studies demonstrated that the human papillomavirus (HPV) type 1 L1 protein, expressed in cos cells by an SV40-based vector, displays conformational epitopes characteristic of native virions. In this study, we analyzed the expression of HPV-1, HPV-6, and HPV-11 L1 proteins in order to determine the forms of conformational epitopes expressed by recombinant L1 proteins. Using both immunofluorescence and immunoprecipitation techniques, polyclonal and monoclonal antibodies (MAbs) generated against native HPV-11 virions reacted with expressed L1 proteins of HPV-6 and/or HPV-11, but not HPV-1. Similarly, polyclonal antibodies and MAbs generated against HPV-1 virions reacted with the expressed L1 protein of HPV-1, but not HPV-6 or HPV-11. Of two MAbs that neutralized HPV-11 infection of murine fetal foreskin xenografts, one reacted with the expressed L1 protein of both HPV-6 and HPV-11, and the other reacted with HPV-11 only. A nonneutralizing conformationally dependent MAb reacted with the expressed L1 protein of both HPV-6 and HPV-11. These results demonstrate that expressed HPV L1 proteins retain type-specific, neutralizing, and nonneutralizing conformational epitopes and that cos cells may be utilized to evaluate host immune responses to such epitopes.

A comparison of clinical diagnoses among male and female soldiers deployed during the Persian Gulf War

A comparison of medical disorders between male and female soldiers during Operations Desert Shield and Desert Storm is presented. Acute gastrointestinal, acute respiratory, dermatologic, dental, psychiatric, orthopedic and optometric disorders were chosen for study. No association between the groups was noted for acute minor illnesses and dental disorders. Men were more likely to be diagnosed with orthopedic and dermatologic disorders (p < 0.001 and p < 0.019). Women were more likely to be diagnosed with psychiatric and optometric disorders (p < 0.001 and p < 0.001). These results can assist military and medical strategists target differential health care to male and female soldiers in the deployed garrison and combat scenarios.

Ambulatory health care needs of women deployed with a heavy armor division during the Persian Gulf War

A study was undertaken to assess the health care needs of women in a combat deployment. During a 6-month period during the Persian Gulf War, 10,165 ambulatory visits from an armor division were studied. The results demonstrate that the health care needs of women can be managed by competently and broadly trained practitioners. Referral sites should provide for gynecologic consultants along with equipment and resources needed to manage pregnancy complications, pelvic pain, and abnormal cervical cytology. It is unlikely that women deployed in this setting pose a significant health care burden attributable solely to their gynecologic needs.

Pure primary osteosarcoma of the ovary presenting as an extensively calcified adnexal mass: a case report and review of the literature

A case of primary ovarian osteosarcoma is reported with a review of the literature. A perimenopausal woman presented with a calcific adnexal mass seen on abdominal radiography, surgical exploration revealed no gross evidence of metastatic disease. Adjuvant chemotherapy was administered due to the reported aggressiveness of this rare tumor. Following eight courses of cisplatin-doxorubicin combination chemotherapy, the patient is without evidence of disease. A differential diagnosis for extensively calcified adnexal masses is provided. Additionally, a rationale for adjuvant chemotherapy is discussed.

Rapidly transported proteins released from nerve and isolated with myelin

An in vitro preparation was used to determine if rapidly transported radiolabeled protein which is isolated with the myelin fraction of frog sciatic nerves is similar to rapidly transported radiolabeled protein released from sciatic nerves. Sciatic nerves along with their eighth and ninth dorsal root ganglia were placed in modified Warburg flasks. The center well of the flasks contained 100 microCi [3H]leucine. The preparation was incubated for 24 h, the sciatic nerve removed and the myelin isolated. The solution in which the sciatic nerve portion of the preparation incubated was removed, dialyzed and lyophilized. The radiolabeled proteins isolated from myelin and those released from the nerve were separated on 10% SDS polyacrylamide gels. Results of this separation revealed that a radiolabeled protein of 100,000 daltons was isolated with myelin and released from sciatic nerves. Incubating isolated myelin in 10 mM EDTA for 14-16 h brought about the release of a protein of 100,000 daltons.

Release of protein from axons during rapid axonal transport: an in vitro preparation

An in vitro system from the frog was used to study fast axonal transport and determine if transported protein is released from the axons. This preparation included the eighth and ninth dorsal root ganglia with their roots, sciatic nerve and gastrocnemius muscle. The preparation was placed in three-compartment chamber with each compartment separated by a silicone grease barrier. The dorsal root ganglia were incubated in [14C]leucine for 5 h in compartment A. The labeled protein was transported down the axon from compartment A to compartment B. The sciatic nerve in compartment B was superfused with frog Ringer. This solution was collected in hourly samples and dialyzed to remove unincoprorated leucine before counting. Incubating the ganglia in 100 microng/ml cycloheximide in frog Ringer blocked the release of labeled protein from the axon. Superfusing compartment B with solution containing 100 microng/ml cycloheximide inhibited axonal and Schwann cell protein synthesis, but did not block the release of labeled protein. It was concluded that the labeled protein released into the superfusing solution was synthesized in the ganglia and transported to the axon before release. SDS acrylamide gels were used to separate the labeled proteins. Sectioning the gels in 2 mm slices and determining the radioactivity showed that 80-85% of the counts were contained in two fast moving bands.