Exploring the added value of hospital-registry data for showing local service outcomes: cancers of the ovary, fallopian tube and peritoneum

OBJECTIVES

To explore the added value of hospital-registry data on invasive epithelial ovarian, tubal and peritoneal cancers.

DESIGN

Historic cohort analyses.

METHODS

Unadjusted and adjusted regression.

SETTING

Major South Australian hospitals.

PARTICIPANTS

1596 women (1984-2015 diagnoses).

RESULTS

5-Year and 10-year survival was 48% and 41%, respectively, equivalent to relative survival for Australia and the USA. After adjusting for age, clinical and geographic factors, risk of ovarian cancer death was 25% lower in 2010-2015 than 1984-1989. Women generally had surgical treatment (87%) in their first round of care. This was more common for younger patients (adjusted OR (95% CIs) 0.17 (0.04 to 0.65) for 80+ vs <40 years) and earlier International Federation of Gynecology and Obstetrics stages (adjusted OR 0.48 (0.13 to 1.78) for stage IIIB/C and 0.13 (0.04 to 0.45) for stage IV vs stage IA). Most (74%) had systemic therapy, which was more common for advanced stages (adjusted ORs >15.0 for stages III and IV vs stage IA). Few (9%) had radiotherapy. Women generally had systemic therapy (74%), without difference by service accessibility and socioeconomic disadvantage, suggesting equity. However, surgery was less common for residents of the most compared with least remote areas (adjusted OR 0.49 (0.24 to 0.99)); and more common prior to adjustment in the highest versus lowest socioeconomic category (unadjusted OR 1.55 (1.01 to 2.39)), but this elevation did not apply after adjustment (adjusted OR 0.19 (0.63 to 2.25)), with the difference largely explained by stage.

CONCLUSIONS

Hospital-registry data add value for assessing local service delivery. Equivalent survival to Australia-wide and USA survival, and temporal gains after adjusting for stage and other patient characteristics are reassuring. Survival gains may reflect therapeutic benefits of more extensive surgery and improved chemotherapy regimens.

Using hospital registries in Australia to extend data availability on vulval cancer treatment and survival

Background

The value of hospital registries for describing treatment and survival outcomes for vulval cancer was investigated. Hospital registry data from four major public hospitals in 1984–2016 were used because population-based data lacked required treatment and outcomes data. Unlike population registries, the hospital registries had recorded FIGO stage, grade and treatment.

Methods

Unadjusted and adjusted disease-specific survival and multiple logistic regression were used. Disease-specific survivals were explored using Kaplan-Meier product-limit estimates. Hazards ratios (HRs) were obtained from proportional hazards regression for 1984–1999 and 2000–2016. Repeat analyses were undertaken using competing risk regression.

Results

Five-year disease-specific survival was 70%, broadly equivalent to the five-year relative survivals reported for Australia overall (70%), the United Kingdom (70%), USA (72%), Holland (70%), and Germany (Munich) (68%). Unadjusted five-year survival tended to be lower for cancers diagnosed in 2000–2016 than 1984–1999, consistent with survival trends reported for the USA and Canada, but higher for 2000–2016 than 1984–1999 after adjusting for stage and other covariates, although differences were small and did not approach statistical significance (p ≥ 0.40). Surgery was provided as part of the primary course of treatment for 94% of patients and radiotherapy for 26%, whereas chemotherapy was provided for only 6%. Less extensive surgical procedures applied in 2000–2016 than 1984–1999 and the use of chemotherapy increased over these periods. Surgery was more common for early FIGO stages, and radiotherapy for later stages with a peak for stage III. Differences in treatment by surgery and radiotherapy were not found by geographic measures of remoteness and socioeconomic status in adjusted analyses, suggesting equity in service delivery.

Conclusions

The data illustrate the complementary value of hospital-registry data to population-registry data for informing local providers and health administrations of trends in management and outcomes, in this instance for a comparatively rare cancer that is under-represented in trials and under-reported in national statistics. Hospital registries can fill an evidence gap when clinical data are lacking in population-based registries.

The value of local registry data for describing cervical cancer management and outcomes over three decades in Australia

Registry data on invasive cervical cancers (n = 1,274) from four major hospitals (1984-2012) were analysed to determine their value for informing local service delivery in Australia. The methodology comprised disease-specific survival analyses using Kaplan-Meier product-limit estimates and Cox proportional hazards models and treatment analyses using logistic regression. Five- and 10-year survivals were 72% and 68%, respectively, equating with relative survival estimates for Australia and the USA. Most common treatments were surgery and radiotherapy. Systemic therapies increased in recent years, generally with radiotherapy, but were less common for residents from less accessible areas. Surgery was more common for younger women and early-stage disease, and radiotherapy for older women and regional and more advanced disease. The proportion of glandular cancers increased in-step with national trends. Little evidence of variation in risk-adjusted survival presented over time or by Local Health District. The study illustrates the value of local registry data for describing local treatment and outcomes. They show the lower use of systemic therapies among residents of less accessible areas which warrants further investigation. Risk-adjusted treatment and outcomes did not vary by socio-economic status, suggesting equity in service delivery. These data are important for local evaluation and were not available from other sources.

The strong prognostic value of KELIM, a model-based parameter from CA 125 kinetics in ovarian cancer: data from CALYPSO trial (a GINECO-GCIG study)

BACKGROUND

Unexpected results were recently reported about the poor surrogacy of Gynecologic Cancer Intergroup (GCIG) defined CA-125 response in recurrent ovarian cancer (ROC) patients. Mathematical modeling may help describe CA-125 decline dynamically and discriminate prognostic kinetic parameters.

METHODS

Data from CALYPSO phase III trial comparing 2 carboplatin-based regimens in ROC patients were analyzed. Based on population kinetic approach, serum [CA-125] concentration-time profiles during first 50 treatment days were fit to a semi-mechanistic model with following parameters: "d[CA-125]/dt=(KPROD∗exp (BETA∗t))∗Effect-KELIM∗[CA-125]" with time, t; tumor growth rate, BETA; CA-125 tumor production rate, KPROD; CA-125 elimination rate, KELIM and K-dependent treatment indirect Effect. The predictive values of kinetic parameters were tested regarding progression-free survival (PFS) against other reported prognostic factors.

RESULTS

Individual CA-125 kinetic profiles from 895 patients were modeled. Three kinetic parameters categorized by medians had predictive values using univariate analyses: K; KPROD and KELIM (all P<0.001). Using Cox multivariate analysis, 5 independent predictors of PFS remained significant: GCIG CA-125 response (favoring carboplatin-paclitaxel arm), treatment arm, platinum free-interval, measurable lesions and KELIM (HR=0.53; 95% CI 0.45-0.61; P<0.001).

CONCLUSIONS

Mathematical modeling of CA-125 kinetics in ROC patients enables understanding of the time-change components during chemotherapy. The contradictory surrogacy of GCIG-defined CA-125 response was confirmed. The modeled CA-125 elimination rate KELIM, potentially assessable in routine, may have promising predictive value regarding PFS. Further validation of this predictive marker is warranted.

Randomized, Double-Blind, Placebo-Controlled Phase II Study of AMG 386 Combined With Weekly Paclitaxel in Patients With Recurrent Ovarian Cancer

Purpose

To estimate the efficacy and toxicity of AMG 386, an investigational peptide-Fc fusion protein that neutralizes the interaction between the Tie2 receptor and angiopoietin-1/2, plus weekly paclitaxel in patients with recurrent ovarian cancer.

Patients and Methods

Patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer were randomly assigned 1:1:1 to receive paclitaxel (80 mg/m2 once weekly [QW], 3 weeks on/1 week off) plus intravenous AMG 386 10 mg/kg QW (arm A), AMG 386 3 mg/kg QW (arm B), or placebo QW (arm C). The primary end point was progression-free survival (PFS). Secondary end points included overall survival, objective response, CA-125 response, safety, and pharmacokinetics.

Results

One hundred sixty-one patients were randomly assigned. Median PFS was 7.2 months (95% CI, 5.3 to 8.1 months) in arm A, 5.7 months (95% CI, 4.6 to 8.0 months) in arm B, and 4.6 months (95% CI, 1.9 to 6.7 months) in arm C. The hazard ratio for arms A and B combined versus arm C was 0.76 (95% CI, 0.52 to 1.12; P = .165). Further analyses suggested an exploratory dose-response effect for PFS across arms (Tarone's test, P = .037). Objective response rates for arms A, B, and C were 37%, 19%, and 27%, respectively. The incidence of grade ≥ 3 adverse events (AEs) in arms A, B, and C was 65%, 55%, and 64%, respectively. Frequent AEs included hypertension (8%, 6%, and 5% in arms A, B, and C, respectively), peripheral edema (71%, 51%, and 22% in arms A, B, and C, respectively), and hypokalemia (21%, 15%, and 5% in arms A, B, and C, respectively). AMG 386 exhibited linear pharmacokinetic properties at the tested doses.

Conclusion

AMG 386 combined with weekly paclitaxel was tolerable, with a manageable and distinct toxicity profile. The data suggest evidence of antitumor activity and a dose-response effect, warranting further studies in ovarian cancer.

Double-blind, controlled phase II study of a 5-HT6 receptor antagonist, SB-742457, in Alzheimer's disease

BACKGROUND

This randomized, double-blind, placebo-controlled study investigated the efficacy and tolerability of the 5-HT6 receptor antagonist, SB-742457, in subjects with mild-to-moderate probable Alzheimer's disease (AD).

METHODS

Participating subjects had a Mini-Mental State Examination (MMSE) score of 12 to 26 after a 4-week, single-blind, placebo run-in phase, and were randomized (2:1:1:2) to receive placebo, SB-742457 5 mg, 15 mg, or 35 mg once daily for 24 weeks. Coprimary efficacy endpoints were the Clinician's Interview-Based Impression of Change with caregiver input (CIBIC+) score and change from baseline in Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) score at Week 24, in the intent-to-treat (ITT) population. A model-based design provided 90% power to detect a linear trend in treatment response across increasing doses and > or =90% power to compare SB-742457 35 mg with placebo.

RESULTS

371 subjects were randomized. In the ITT population (n=357), linear trend analysis at Week 24 suggested a dose response for CIBIC+ with a mean slope of -0.05 points/5-mg dose increase (95% confidence interval [CI]: -0.09, -0.01; p=0.016). The dose response slope for change from baseline in ADAS-Cog was -0.22 points/5-mg dose increase (95% CI: -0.45, 0.01; p=0.059). The adjusted mean treatment difference from placebo at Week 24 for SB-742457 35 mg (-0.31) was significant on CIBIC+ (95% CI: -0.62, -0.00; p=0.047) but non-significant on ADAS-Cog (-1.28 [95% CI: -2.96, 0.40]; p=0.135). Adverse events occurred in 24-37% in the SB-742457 groups vs 29% for placebo; 11-16% discontinued SB-742457 vs 15% for placebo.

COMMENTS

SB-742457 was generally safe and well tolerated and may be efficacious in AD.

Does retention of the ovaries improve long-term survival after hysterectomy? A gynecological oncological perspective

Ovarian cancer is, in most cases, a lethal disease as it is virtually impossible to diagnose at an early stage and almost impossible to treat successfully when detected at an advanced stage. In postmenopausal women, there is no prevention for ovarian cancer but oophorectomy. Therefore, from the gynecological oncological perspective, where benign gynecological pathology requires surgery in postmenopausal women, oophorectomy should be the preferred option.

A tale of two cancers: collision presentation of ovarian carcinoma and lymphoma

Synchronous malignancies are rare diagnostic and treatment challenges. Here we present three cases of synchronous ovarian cancer and lymphoma. Both malignancies were recognised in the same histopathology sections. This report discusses diagnosis and management dilemmas with a brief literature review. The simultaneous presentation of ovarian cancer and lymphoma has not previously been reported.

Phenotypes of the ovarian follicular basal lamina predict developmental competence of oocytes

BACKGROUND

The ovarian follicular basal lamina underlies the epithelial membrana granulosa and maintains the avascular intra-follicular compartment. Additional layers of basal lamina occur in a number of pathologies, including pili annulati and diabetes. We previously found additional layers of follicular basal lamina in a significant percentage of healthy bovine follicles. We wished to determine if this phenomenon existed in humans, and if it was related to oocyte function in the bovine.

METHODS AND RESULTS

We examined follicles from human ovaries (n = 18) by electron microscopy and found that many follicles had additional layers of basal lamina. Oocytes (n = 222) from bovine follicles with normal or unusual basal laminas were isolated and their ability to undergo in vitro maturation, fertilization and culture to blastocyst was compared. Healthy bovine follicles with a single layer of basal lamina had oocytes with significantly (P < 0.01) greater developmental competence than healthy follicles with additional layers of follicular basal lamina (65% versus 28%).

CONCLUSIONS

These findings provide direct evidence that the phenotype of the follicular basal lamina is related to oocyte competence.

Characterization of intestinal inflammation and identification of related gene expression changes in mdr1a(-/-) mice

Multidrug resistance targeted mutation (mdr1a (-/-) ) mice spontaneously develop intestinal inflammation. The aim of this study was to further characterize the intestinal inflammation in mdr1a (-/-) mice. Intestinal samples were collected to measure inflammation and gene expression changes over time. The first signs of inflammation occurred around 16 weeks of age and most mdr1a (-/-) mice developed inflammation between 16 and 27 weeks of age. The total histological injury score was the highest in the colon. The inflammatory lesions were transmural and discontinuous, revealing similarities to human inflammatory bowel diseases (IBD). Genes involved in inflammatory response pathways were up-regulated whereas genes involved in biotransformation and transport were down-regulated in colonic epithelial cell scrapings of inflamed mdra1 (-/-) mice at 25 weeks of age compared to non-inflamed FVB mice. These results show overlap to human IBD and strengthen the use of this in vivo model to study human IBD. The anti-inflammatory regenerating islet-derived genes were expressed at a lower level during inflammation initiation in non-inflamed colonic epithelial cell scrapings of mdr1a (-/-) mice at 12 weeks of age. This result suggests that an insufficiently suppressed immune response could be crucial to the initiation and development of intestinal inflammation in mdr1a (-/-) mice.

Ovarian cancer - diagnosis and management

BACKGROUND

Epithelial ovarian cancer presents most often as late stage disease due to a lack of effective screening tests and vagueness of symptoms.

OBJECTIVE

This article outlines the diagnosis and management of ovarian cancer.

DISCUSSION

Women with suspected ovarian cancer are best managed in a gynaecological treatment unit offering multidisciplinary care. Surgery is usually needed both to make a diagnosis and for definitive treatment and referral to a specialty trained gynaecological oncologist is appropriate. Most women will also require chemotherapy. Ovarian cancers have good sensitivity to several drugs but relapse rates are high. This means that ovarian cancer is now seen as a chronic disease with often several episodes of remission, relapse and treatment. The psychological impact of this diagnosis both on the woman and her family are significant and best dealt with proactively.

A new prognostic model for FIGO stage 1 epithelial ovarian cancer

BACKGROUND

No consensus exists which patients with surgical stage 1 epithelial ovarian should receive postoperative chemotherapy. The purpose of this study was to evaluate the prognostic impact of preoperative CA-125 and to establish a prognostic index to identify patients in different risk categories.

METHODS

Data of 600 surgically staged patients with FIGO stage 1 EOC treated in eleven gynecological cancer centers in Australia, the USA and Europe were analyzed. Eligible patients include those with invasive EOC where a preoperative CA-125 was obtained and standard surgical staging performed. Overall survival (OS) was chosen as study endpoint. Preoperative CA-125 values were compared with other prognostic factors, and univariate and multivariate Cox models were calculated.

RESULTS

Two hundred and one patients (33.5%) had preoperative CA-125 < or =30 U/ml and CA-125 levels < or =30 U/ml were associated with lower grade, sub-stage 1A and mucinous histologic cell type. Patients with elevated CA-125 levels were more likely to receive chemotherapy. OS probability was 95% and 85% for patients with pretreatment CA-125 < or =30 U/ml and >30 U/ml, respectively (p 0.003). Multivariate analysis confirmed preoperative serum CA-125 >30 U/ml (OR 2.7) and age at diagnosis >70 years (OR 2.6) as the only independent predictors for overall survival.

CONCLUSION

Pretreatment of CA-125 < or =30 U/ml dominates over histologic cell type, sub-stage and grade to identify a subgroup of FIGO stage 1 patients with a genuinely good prognosis with extremely good survival and who could possibly be spared with adjuvant chemotherapy.

Prognostic Importance of Preoperative CA-125 in International Federation of Gynecology and Obstetrics Stage I Epithelial Ovarian Cancer: An Australian Multicenter Study

Purpose

To evaluate the prognostic significance of preoperative CA-125 levels on overall survival of patients with International Federation of Gynecology and Obstetrics (FIGO) stage I epithelial ovarian cancer (EOC).

Patients and Methods

Data from 518 patients with FIGO stage I EOC treated in seven gynecologic oncology centers throughout Australia between 1990 and 2002 were analyzed. Patients with borderline tumors and nonepithelial ovarian carcinomas were excluded, as were women in whom CA-125 had not been determined preoperatively. Preoperative CA-125 levels were studied in surgically staged and incompletely staged patients and compared with prognostic factors, such as substage, grade, and histologic type. Multivariate Cox models were calculated.

Results

CA-125 levels more than 30 U/mL were associated with higher grade, substage 1B and 1C, nonmucinous histologic type, and older age. In univariate analysis, higher histologic grade, the absence of surgical staging, and preoperative CA-125 levels more than 30 U/mL were associated with impaired survival. Multivariate analysis identified histologic grade, preoperative CA-125, and surgical staging as independent predictors for survival. In the subgroup of completely surgically staged patients, the 5-year overall survival rate was 82% (95% CI, 76% to 88%) for patients with CA-125 levels more than 30 U/mL and 95% (95% CI, 90% to 99%) for patients with CA-125 levels of 30 U/mL or less (P = .028). In the group of incompletely staged patients, the 5-year survival rates were similar for patients with elevated and normal serum CA-125 levels.

Conclusion

Complete surgical staging, histologic grade, and preoperative serum CA-125 levels are independent prognostic factors and should be included in the decision making for chemotherapy.

Abnormal Pap Smears in Teenage Mothers and the Association with Domestic Violence, Homelessness, and Chlamydia

OBJECTIVE

To assess the incidence of Pap smear abnormalities and cervical intraepithelial neoplasia (CIN) on cervical biopsy results in teenage mothers and to establish if there are associations with social disruption.

PATIENTS AND METHODS

A prospective study of 498 pregnant teenagers was performed at three Australian hospitals. Enrolled patients had a Pap smear performed. Women with abnormal Pap smear results underwent colposcopy with directed biopsy of the cervix. Independently, women were interviewed to identify demographic and social variables. Variables associated with an abnormal Pap smear result were analyzed using a mixed model of analysis.

RESULTS

Four hundred fifty-seven patients participated in the study (response rate, 92%). The prevalences of low- and high-grade squamous intraepithelial lesions on Pap smear were 37 in 1,000 and 13 in 1,000, respectively. The prevalence of CIN 1 was 35 in 1,000 and of CIN 2,3 was 15 in 1,000. In univariate analysis, teenagers with abnormal Pap smear results were significantly more likely to have a history of exposure to domestic violence (odds ration [OR], 7.10; 95% CI, 2.76-18.53), be homeless (OR, 6.82; 95% CI, 2.59-17.83), to have coexisting Chlamydia infection (OR, 5.44; 95% CI, 1.59-17.64), or be current users of illegal drugs or have a history of illegal drug use (current: OR, 3.06; 95% CI, 1.22-7.69; history: OR, 2.75; 95% CI, 1.04-7.53). Exposure to domestic violence, homelessness, and Chlamydia infection remained significant on multivariate analysis (p < .05).

CONCLUSIONS

The incidence of CIN in pregnant teenagers is high and is associated with domestic violence, homelessness, and Chlamydia infection.

A phase I study of paclitaxel and altretamine as second-line therapy to cisplatin regimens for ovarian cancer

PURPOSE

The efficacy and pharmacokinetics of paclitaxel when combined with altretamine for ovarian cancer were studied.

METHODS

A group of 30 patients, whose only chemotherapy was one or more cisplatin-based non-paclitaxel-containing regimens and whose ovarian cancer failed to respond or had relapsed within 6 months of their last platinum regimen, received paclitaxel as a 3-h intravenous infusion and altretamine given orally in four divided doses daily for 14 days repeated every 28 days. Doses were escalated from paclitaxel/altretamine 135/150 mg/m2 to 250/300 mg/m2 in cohorts of three patients.

RESULTS

The dose-limiting toxicities at 250/300 mg/m2 were WHO grade 3 myalgias and arthralgias in two patients and grade 3 lethargy, stomach cramps, peripheral neuropathy and vomiting in single patients. Considering all dose levels in cycle 1, 16 patients had grade 3 or 4 neutropenia but there was only one episode of febrile neutropenia. Other grade 3 toxicities were vomiting in four patients, myalgias in three, peripheral neuropathy in two and lethargy in two. Grade 3 alopecia occurred in 23 patients. Three patients achieved a complete response and 12 achieved a partial response for an overall objective response rate of 50%. Responses occurred at all dose levels of 175/150 mg/m2 and higher. The median freedom from progression was 35 weeks, with a median survival of 55 weeks. Altretamine did not alter the pharmacokinetics of paclitaxel and there were no consistent differences in paclitaxel pharmacokinetic parameters or toxicities between course 1 and 2. No dose-response relationships were evident above paclitaxel/altretamine 175/150 mg/m2.

CONCLUSION

Paclitaxel and altretamine can be safely combined and with a high response rate in relapsed ovarian cancer, justifying further studies with this combination.

Reliability and sensitivity of joint space measurements in hand radiographs using computerized image analysis

OBJECTIVE

To establish the sensitivity and reliability of proximal interphalangeal (PIP) and metacarpophalangeal (MCP) mean joint space measurements using standard clinical radiographs of healthy subjects, in order to determine the limits at which a change in radiographic joint space could indicate a change in actual joint size.

METHODS

Repeat hand radiographs of healthy subjects were taken using standard techniques at 3-5 day intervals with the hands flat (5 posteroanterior radiographs in 8 subjects) or in 6 different flexed positions on a single occasion (8 subjects). The mean joint space was determined using custom soft ware and was validated manually. Measurement reproducibility within subjects, within films, and between hand positions was assessed by analysis of variance.

RESULTS

In repeat radiographs taken in the standard clinical position, the precision of individual join space measurements indicates that changes > 0.11 mm (approximately 7%) would represent an actual physical change in joint space width (with 95% probability). Averaging measurements across fingers for a single subject decreases the detectable change to 0.05 mm (approximately 3%). With increasing flexure, radiographic joint space tended to increase in MCP and decrease in PIP.

CONCLUSION

Mean finger joint space measured from standard clinical radiographs is a reliable and sensitive measurement in healthy subjects even with some change in hand position. Work is required to establish whether the joint space change measured from serial radiographs of patients with arthritis over a period of 6-12 mo exceeds the detectable limits of change derived in this study.

The clinical pharmacokinetics of a new pharmacokinetically enhanced formulation of amoxicillin/clavulanate

BACKGROUND

A new oral pharmacokinetically enhanced formulation of the broad-spectrum antibiotic amoxicillin/clavulanate has been developed to provide more effective therapy against resistant pathogens than is provided by currently available formulations by maintaining therapeutically useful plasma amoxicillin concentrations for a longer period after dosing.

OBJECTIVE

This study explored the pharmacokinetics of the new oral formulation of amoxicillin/clavulanate in healthy male and female subjects.

METHODS

A single oral dose of pharmacokinetically enhanced amoxicillin/clavulanate (2000/125 mg; 16:1 ratio) was administered to subjects at the start of a meal. After dosing, blood samples were collected at frequent intervals up to 12 hours, and plasma was assayed for amoxicillin and clavulanate concentrations using validated procedures. The new formulation consisted of 1 layer of immediate-release amoxicillin and clavulanate and another of sustained-release amoxicillin in a proportion such that for an amoxicillin minimum inhibitory concentration (MIC) of 4 microg/mL, the time above the MIC (T >MIC) would be approximately > or = 40% over a 12-hour dosing interval.

RESULTS

The study enrolled 24 and 31 healthy male and female subjects, respectively. Their mean age was 35 years (range, 18-58 years) and mean body weight was 69 kg (range, 51-86 kg). After the expected sharp peak in plasma amoxicillin concentration, there appeared to be a slower decline with the pharmacokinetically enhanced formulation than is usually seen with conventional formulations, and there was evidence of a second amoxicillin absorption phase. The mean T >MIC for an amoxicillin MIC of 4 microg/mL was 49.4% of a 12-hour dosing interval, a value that cannot be achieved with existing approved doses and formulations of amoxicillin/clavulanate. By 12 hours, plasma amoxicillin concentrations were very low (approximately 0.05 microg/mL), suggesting no expectation of notable dose-to-dose accumulation on repeat dosing with a BID regimen. The terminal half-lives of amoxicillin (1.27 hours) and clavulanate (1.03 hours) with the new formulation were similar to those of existing formulations of amoxicillin/clavulanate. No deaths or serious adverse events were reported.

CONCLUSIONS

The enhanced pharmacokinetic profile of amoxicillin/clavulanate seen in this study suggests that this formulation is likely to be highly effective for the oral treatment of infections caused by bacteria--including beta-lactamase-producing organisms--and strains with amoxicillin MICs < or = 4 microg/mL.

The morbidity of surgery and adjuvant radiotherapy in the management of endometrial carcinoma

A retrospective review of side effects and complications of treatment in 522 patients with endometrial cancer managed in a gyneoncology unit was conducted. This study evaluated 517 patients who underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH BSO). Lymphadendectomy or lymph node sampling was performed with the primary surgery in 264 and 41 cases, respectively. Postoperative radiotherapy was given as external beam or vault brachytherapy. Serious morbidity included lymphedema, hemorrhage, and vaginal stenosis. Lymphadenectomy was associated with lymphedema and lymphocyst formation in 11% of the cases. Vascular injury associated with lymphadenectomy occurred in 0.7% of the cases; however, this was satisfactorily managed through adequate surgical training and experience by staff within the unit. The incidence of vaginal stenosis (54.7%) following postoperative vault brachytherapy was a particular concern for clinical follow-up and sexual function. Although many women were not sexually active prior to treatment, those who were had high levels of sexual dysfunction, even when vaginal stenosis was not present.

Lack of effect of gemifloxacin on the steady-state pharmacokinetics of theophylline in healthy volunteers

Gemifloxacin is a novel fluoroquinolone, currently in development for the treatment of respiratory tract infections. This double-blind (with respect to gemifloxacin), randomized, crossover study investigated the possibility of pharmacokinetic interaction between gemifloxacin and theophylline. After a 4-8-day run-in phase to establish the dose of theophylline required to achieve a trough plasma concentration range of 8-15 mg/l, 15 healthy volunteers entered a randomized treatment phase. Volunteers then received oral theophylline, 300-400 mg twice daily, for 22 days. On days 5-11 and 16-22, they also received either placebo or gemifloxacin, 320 mg p.o. once daily, in a crossover fashion. Blood samples were collected up to 12 h after the morning dose of theophylline on days 11 and 22. Theophylline pharmacokinetics were not affected by the co-administration of gemifloxacin. The maximum plasma concentration (C(max)) for theophylline ranged from 8.12 to 17.71 mg/l and from 8. 79 to 16.35 mg/l during concomitant administration with gemifloxacin and placebo, respectively. The corresponding ranges of the area under the plasma concentration-time curve from time zero to the last quantifiable plasma concentration (AUC((0-12))) were 84.6-177.5 mg. h/l and 94.8-165.1 mg.h/l during gemifloxacin and placebo administration, respectively. The point estimates (90% confidence intervals) for dose-normalized AUC((0-12)) and C(max) (theophylline + gemifloxacin):(theophylline + placebo) were 0.99 (0.93, 1.05) and 1.02 (0.93, 1.11), respectively, which were entirely within the equivalence range (0.80, 1.25). The co-administration of gemifloxacin and theophylline was well tolerated, with no clinically significant changes seen in vital signs, 12-lead electrocardiogram readings or laboratory parameters. Adverse events were generally transient, mild to moderate in nature and similar during the gemifloxacin and placebo treatment periods. In conclusion, theophylline and gemifloxacin may be co-administered without any adjustment in theophylline dose.

Lack of effect of gemifloxacin on the steady-state pharmacodynamics of warfarin in healthy volunteers

Gemifloxacin is a novel fluoroquinolone with a broad spectrum of activity. This double-blind, randomized, parallel-group study was designed to demonstrate the lack of effect of steady-state concentrations of gemifloxacin on the pharmacodynamic effects of warfarin. Healthy male subjects received loading doses of warfarin on days 1 and 2. The warfarin dose was freely titrated until day 10, with the aim of achieving a stable international normalized ratio (INR) for prothrombin time within the range 1.3-1.8 by day 14. On days 14-24 the dose of warfarin was fixed. On days 18-24, subjects also received 320 mg of gemifloxacin or matched placebo, once daily. Thirty-five subjects entered into and completed the co-administration phase of the study. The mean (standard deviation) baseline INR (mean of days 16-18) and INR for day 24 for gemifloxacin plus warfarin were 1.52 (0.12) and 1.46 (0.15), respectively. Corresponding values for placebo plus warfarin were 1. 46 (0.11) and 1.42 (0.17). The point estimate (90% confidence interval) for the difference in day 24 INR, adjusted for baseline, between gemifloxacin and placebo was 0.02 (-0.08, 0.12), which translates to an INR (relative to placebo least squares mean of 1.43) of 1.02 (0.95, 1.09). The 90% confidence interval for the difference in INR between the gemifloxacin and placebo groups was completely contained within the 25% equivalence range. There were no changes of clinical significance in vital signs, 12-lead electrocardiogram readings or laboratory parameters for any subject during the co-administration phase of the study, and no adverse experiences relating to coagulation were reported during this period. It is concluded that the pharmacodynamic effects of warfarin are not affected by gemifloxacin, and therefore both drugs can be co-administered without dosage adjustment.

The effect of steady-state ropinirole on plasma concentrations of digoxin in patients with Parkinson's disease

AIMS

The aim of this single-blind study was to assess the effect of ropinirole, a novel treatment for Parkinson's disease, on the steady-state pharmacokinetics and safety of digoxin in 10 patients with Parkinson's disease.

METHODS

There were three parts to the study: digoxin once daily plus placebo three times daily for 1 week; digoxin once daily plus ropinirole three times daily for 6 weeks; and digoxin once daily plus placebo three times daily for 1 week. Serial blood samples were collected over 24 h at the end of each part of the study for pharmacokinetic assessment. Pre-dose blood samples were collected on specific days throughout the study to assess the attainment of steady-state plasma levels of digoxin. The primary endpoints were AUC(0, tau) and Cmax for digoxin.

RESULTS

There was a mean decrease of 10% in digoxin AUC (0, tau) (90% CI: 0.79, 1.01) and a 25% decrease in digoxin Cmax (90% CI: 0.58, 0.97) when ropinirole was co-administered, compared with digoxin alone Cmin plasma values for digoxin, however, were fairly constant throughout the study (point estimates 0.99, 95% CI: 0.85, 1.15). Changes in trough levels of digoxin are believed to be the most reliable way of assessing steady-state concentrations of digoxin, and therefore the clinical significance of an interaction. Changes in Cmax are too readily influenced by other factors.

CONCLUSIONS

These results therefore indicate that on pharmacokinetic grounds no dose adjustment is necessary for digoxin co-administered with ropinirole.

Patients' views of the care given by district nurses

Understanding the actions that make patients feel 'cared for' by district nurses can help staff tailor their work to meet patients' needs. Patients in one study felt that a trusting nurse/patient relationship is the basis of good nursing.

Evening dosing is associated with higher plasma concentrations of pranlukast, a leukotriene receptor antagonist, in healthy male volunteers

AIMS

To study the magnitude of differences in the pharmacokinetics of pranlukast, after morning and evening administration.

METHODS

Pranlukast (300 mg) was administered to 12 healthy male volunteers on two separate occasions, either in the morning or evening. Both doses were given 30 min after a standard high fat content meal. Blood samples were collected up to 18 h postdose. Plasma was assayed by high performance liquid chromatography. Standard pharmacokinetic and statistical analyses were performed.

RESULTS

Statistically significant (P < 0.05) increases were noted in AUC(o,t) (56%) and tmax (2.5 h) after evening administration. Cmax was 14% higher after evening dosing (95% C.I. 0.71-1.84).

CONCLUSIONS

Pranlukast bioavailability is apparently increased after evening dosing as compared with morning administration. Higher night-time and early morning plasma concentrations may confer additional therapeutic benefit at a time when asthmatics are at greatest risk of developing bronchospasm.

Cardiovascular pharmacology of aqueous extract of the leaves of Bridelia atroviridis Muell. Arg. (Euphorbiaceae) in the rat

Lyophilised decoction (10%) of the leaves of Bridelia atroviridis Muell. Arg. (Euphorbiaceae) was studied in the rat cardiovascular system. In vivo, the extract (15 and 30 mg/kg) caused a decrease of arterial pressure and a decrease of heart rate in an anaesthetized rat (ethylcarbamate 1.2 g/kg). If administrations of Bridelia were repeated (three times) a tachyphylaxie phenomena was observed. After administrations of adrenaline, noradrenaline, acethylcholine and isoprenaline the extract had no effect on the action of these neuromediators on blood pressure. In vitro the extract induced dose-dependent negative inotropic and chronotropic effects in isolated rat heart. It was ineffective in rat aorta preparations. Bridelia seemed to have a direct effect on rat heart. Hypotension is not due to an action on the vessels. The extract did not appear to interact with adrenergic nor cholinergic receptors. However, the extract was able to potentiate barium chloride induced contractions of rat aorta preparations. The extract might act through potential dependent calcium channels.

5-Hydroxytryptamine and beta-adrenoceptors in rat isolated atria

The positive chronotropic effect of a high concentration of 5-hydroxytryptamine (5-HT) in rat isolated atria results mainly from a tyramine-like mechanism and is linked to an increase in cAMP production by an indirect stimulation of beta-adrenoceptors. Using this preparation, we have compared the action of tyramine and 5-HT. The tyramine (0.15 microM)-induced increase in atrial rate was suppressed by atenolol (a beta 1-blocking drug) and by nadolol (a beta 1 beta 2-blocker), while the positive chronotropic effect of 5-HT was reduced by atenolol and suppressed by nadolol. The 5-HT-induced elevation in cAMP was unchanged in the presence of atenolol and abolished by nadolol. The involvement of beta 2-adrenoceptors in the effects of 5-HT could result from competition between 5-HT and noradrenaline at the beta 1-adrenoceptors that results in a fixation of noradrenaline on beta 2-adrenoceptors.

cGMP release in rat mesenteric arterioles and in conduit mesenteric artery

1. Relaxing factors were studied in two perfused preparations of the same vascular area in the rat: resistance mesenteric arterioles and conduit mesenteric artery. 2. In both preparations, an acetylcholine (ACh) infusion inhibited noradrenaline (NA) vasoconstrictor effects but at a ten-times greater concentration in conduit artery than in resistance arterioles. 3. Endothelium destruction with hypotonic Krebs solution did not change basal perfusion pressure, but increased NA responses and suppressed ACh inhibitory effects in arterioles and arteries. Likewise, L-NAME abolished the ACh effect in mesenteric arterioles but only reduced it in mesenteric artery. 4. Basal release of cyclic GMP was significantly greater in mesenteric artery than in resistance arterioles. By contrast, ACh-induced cGMP release was higher in mesenteric arterioles. Endothelium removal did not change basal release of cGMP in mesenteric arterioles but reduced it in mesenteric artery. 5. These results suggest that in basal conditions several relaxing factors are present in higher concentrations in conduit mesenteric artery than in resistance mesenteric arterioles. However, although it releases higher basal amount of cGMP, this vessel has a reduced role in vascular control than do smaller arteries.

Biochemical characterization of the mechanisms involved in the 5-hydroxytryptamine-induced increase in rat atrial rate

Several possible mechanisms for 5-hydroxytryptamine (5-HT)-induced tachycardia in rat have been suggested: an activation of 5-HT1C or 5-HT2 receptors, an indirect sympathomimetic effect or a mechanism independent of 5-HT2 receptor stimulation. The aim of this study was to investigate the involvement of these mechanisms in the 5-HT-induced increase in rat atrial rate using biochemical methods. Indeed, the 5-HT1C and 5-HT2 receptors are linked to phosphoinositide hydrolysis and the noradrenaline (NA) released by 5-HT can stimulate the beta 1-adrenergic receptors linked to adenylate cyclase stimulation. The effect of varying concentrations of 5-HT on inositol phospholipid hydrolysis and adenylate cyclase activity of the rat isolated atria were measured. 5-HT (2 microM) did not modify total inositol phosphate (IP) production, while 5-HT 10 and 50 microM increased it 2-fold. The 5-HT2 antagonist ketanserin (1 microM) abolished IP accumulation induced by 5-HT microM), which indicates that this accumulation is 5-HT2 and not 5-HT1C receptor-mediated. Moreover, cyclic AMP (cAMP) formation was enhanced by 5-HT (5, 10, 20 and 50 microM). When atria were incubated 10 min with the beta-adrenergic receptor antagonist nadolol (1 microM), the increase in the cAMP level induced by 5-HT, whatever its concentration (10, 20 or 50 microM), was inhibited. Treating rats with reserpine (2.5 mg/kg, i.p., 48 and 24 hr before experimentation), which caused NA depletion in the heart, seemed to reduce the stimulating effect of 5-HT 10 and 50 microM on adenylate cyclase activity. Thus, the 5-HT-induced increase in cAMP is indirectly due to the activation of the beta-adrenergic receptors by the NA released by 5-HT. It is concluded that 5-HT stimulates both phosphoinositide turnover and adenylate cyclase activity in the rat isolated atria by activation of 5-HT2 receptors and by an indirect sympathomimetic effect.

Effect of ketanserin on monoamines and neuropeptide Y in brain and peripheral tissues of normotensive (WKY) and spontaneously hypertensive (SHR) rats

The effect of one intraperitoneal (i.p.) injection of ketanserin (K) (20mg/kg) on the levels of monoamines and neuropeptide Y (NPY) in some central and peripheral tissues was examined in normotensive (WKY) and spontaneously hypertensive (SHR) rats. In WKY rats, K induced a depletion of norepinephrine (NE) in the hypothalamus, the medulla, the atria and the caudal artery together with a decrease in dopamine level (DA) in the hypothalamus and in serotonin level (5-hydroxytryptamine, 5-HT) in the medulla. The reduction reached 25% to 35%. In SHR, NE and DA levels in the hypothalamus, and NPY levels in the caudal artery were lower than in WKY, while NE was higher in the adrenals. After treatment with K, NE, 5-HT, 5-HIAA (5-hydroxyindoleacetic acid) and NPY in the medulla were increased by about 30% to 50% while NE in the caudal artery was reduced by about the same value as in WKY. These results indicate that K-induced release of monoamines is not linked to NPY release. Moreover, monoamine and NPY sensitivity to K differ in SHR and WKY rats.

Beta-core fragment of human chorionic gonadotropin in cervical intraepithelial neoplasia (CIN)

A low molecular weight glycoprotein immunologically identical with the beta-core fragment of hCG (beta C-hCG) has been described in invasive tumors of the genital tract, particularly carcinoma of the cervix. A previous report has also suggested increased urinary concentrations in subjects with cervical intraepithelial neoplasia (CIN). This prospective study of 107 patients with CIN was conducted to determine concentrations of beta C-hCG in the urine compared to a reference population without CIN. All subjects underwent a cervical smear and colposcopy, with biopsy when indicated. Between 11 and 18% of patients had urinary concentrations of beta C-hCG greater than the upper limit of the reference group and these results were confirmed when corrected for urinary creatinine concentration. A substantial number of subjects (19%) also had a positive result in a C-terminal immunoassay. It is concluded that preinvasive carcinoma of the cervix may secrete hCG or beta C-hCG in the earliest stages although measurement of beta C-hCG is unlikely to prove to be a valuable diagnostic marker in CIN.

Modulation of noradrenergic transmission in the rat isolated portal vein: Role of prejunctional α2-adrenoceptors and β-adrenoceptors

1. The effect of several adrenoceptor agonists and antagonists on the spontaneous and stimulus-evoked release of [3H]noradrenaline was studied in rat isolated portal vein. 2. Yohimbine (10(-6)M) increased the stimulus-evoked [3H]noradrenaline efflux. Adrenaline alone (3 x 10(-6)M) was without effect, while it increased the resting efflux when added together with yohimbine. 3. Propranolol alone was without effect on the release of [3H]noradrenaline. When added (2 x 10(-6)M) at the same time as yohimbine, it reduced the stimulation-induced 3H efflux. When added before adrenaline and yohimbine, propranolol (10(-5)M) reduced both spontaneous and stimulus-evoked release of [3H]noradrenaline. 4. The effect of several beta-blocking drugs was measured on the enhancing effect of yohimbine on the stimulation-evoked 3H efflux. The beta 1-adrenoceptor blocking drugs: atenolol (5 x 10(-6) and 10(-5) M), metoprolol (5 x 10(-6) and 10(-5) M), like the more selective bisoprolol (2 x 10(-6) and 4 x 10(-6) M) inhibited yohimbine activity. Likewise, propranolol (2 x 10(-6) and 5 x 10(-6)M) and the beta 2-adrenoceptor blocker ICI 118551 exhibited an antagonistic effect. 5. These results indicate the possibility for noradrenaline to activate presynaptic beta-adrenoceptors in rat portal vein. They show an interaction between the presynpatic alpha 2- and beta-adrenoceptor mediated systems in the release of noradrenaline. They suggest the presence and the activity of facilitatory beta 1-adrenoceptors.

Uptake of 5-hydroxytryptamine in rat isolated atria

1. The mode of 5-hydroxytryptamine (5-HT) uptake by the rat isolated atria was studied and compared to noradrenaline (NA) uptake. 2. Rat isolated atria were incubated with 14C-5-HT (46 microM) or 3H-NA 0.4 microM). After washing, the radioactivity fixed in atria was counted and the total NA, 5-HT and 5-hydroxyindol-3-acetic acid (5-HIAA) atria contents were measured by HPLC. 3. 14C-5-HT uptake was reduced in atria from 6-hydroxydopamine (100 mg/kg, i.p., 48 hr before experiments) or reserpine (2.5 mg/kg, i.p., 24 and 48 hr before experiments) pretreated rats. 4. The incubation of atria with 5-HT (50 microM) at the same time as 3H-NA reduced the 3H-NA value fixed. 5. Addition of desipramine (1 microM) or hydrocortisone (150 microM) before the incubation of atria with 14C-5-HT was without any effect on 14C-5-HT uptake. In contrast, fluvoxamine (1 microM) or indalpine (5 microM) caused a slight inhibition. 6. These data indicate that 5-HT is taken into the NA storage vesicles within the atria sympathetic nerves. This uptake does not use the NA carrier and involves partly the 5-HT carrier. An extraneuronal accumulation was noticed and a part of it is intracellular.

Effects of chloral, chloralose and pentobarbitone on monoamine and (neuropeptide Y) NPY levels in various tissues in the rat

Sampling of blood or tissues in experimental animals need frequently a general anesthesia. Some anesthetic agents are known to modify plasma levels of catecholamines; moreover NPY is co-released with noradrenaline or adrenaline under certain conditions. Thus, we investigated the effect of three general anesthetic agents, chloral, chloralose and pentobarbital (pentobarbitone) on the levels of monoamines and NPY in rat hypothalamus, medulla, atria and adrenals. Monoamines were analysed by high pressure liquid chromatography using an electrochemical detection and NPY was measured by radioimmunoassay (immunoradiometric assay, IRMA). Chloralose or pentobarbitone did not affect monoamine tissue levels. In contrast, chloral increased 5-hydroxyindolacetic acid and to a lesser extent serotonin levels in the hypothalamus. NPY tissue levels did not change whatever the anesthetic used. These results must be taken into account in pharmacological or toxicological studies which need the use of a general anesthesia.

Increased age and mortality associated with cervical carcinomas negative for human papillomavirus RNA

Attempts to relate presence and type of human papillomavirus in cervical carcinoma with prognosis have yielded conflicting results. To further investigate this relation, the association between survival of cervical cancer patients after diagnosis and the presence of human papillomavirus (HPV) RNA within the tumour was assessed retrospectively. Formalin-fixed biopsy specimens from 212 patients with cervical carcinoma who had been followed for up to 6 years were tested by in-situ hybridisation with 125I-labelled riboprobes. HPV-RNA-positive women were 11.9 years younger than HPV-negative women at diagnosis (p less than 0.001). Case-fatality rates from cervical cancer rose with absence of HPV RNA, age at diagnosis, or FIGO stage. Multivariate analysis confirmed that absence of detectable HPV RNA and advanced FIGO stage were independent risk factors. No differences in survival between HPV types 16, 18, 31, or 33 were seen. These observations suggest that cervical carcinoma patients fall into two groups--a younger, HPV-RNA-positive group, with a better prognosis, and an older, HPV-RNA-negative group with poorer prognosis. Treatment regimens for the two groups may need to differ.

Cardiovascular effects of intracerebroventricular injections of (+/-)-nebivolol and its enantiomers--a comparison with those of metoprolol in the rat

The cardiovascular effects of (+/-)-nebivolol, a potent beta 1-adrenoceptor antagonist, and its enantiomers, (+)-nebivolol (SRRR) and (-)-nebivolol (RSSS) in normotensive anaesthetized rats, have been investigated using metoprolol as a reference substance. The drugs decreased blood pressure and heart rate immediately after i.c.v. injection. These effects paralleled the beta-blocking potencies ((+)- greater than (+/-)-greater than (-)-nebivolol). Metoprolol induced a weaker hypotension than (+/-)-nebivolol, and a long-lasting reduction in stroke volume. As reported after i.v. administration, (+/-)-nebivolol and isomers by the i.c.v. route decreased peripheral vascular resistance following i.c.v. administration while metoprolol increased it. These effects are centrally mediated since cardiovascular responses to isoprenaline i.v. remained unchanged.

Prognostic factors in patients with stage I epithelial ovarian cancer

We analyzed factors predictive of relapse risk in patients with stage I invasive epithelial ovarian cancer: 252 patients from the Princess Margaret Hospital provided a data base for hypothesis generation, and data on 267 patients from the Norwegian Radium Hospital were used for hypothesis testing. The outcomes in most analyses in the two series were very similar, validating the following conclusions. Differentiation (grade) was the most powerful predictor of relapse, followed by dense adherence (which resulted in outcomes equivalent to those in stage II) and, finally, large-volume ascites. When the effects of these three factors were accounted for, then none of the following were prognostic: bilaterality (stage Ib), cyst rupture (stage Ic), capsular penetration (stage Ic), tumor size, histologic subtype, patient age, year of diagnosis, and postoperative therapy. These results allow simplification of stage I substaging, as only differentiation, dense adherence, and large-volume ascites (? peritoneal cytology) need be considered. The 5-year relapse-free rate was 98% in patients with grade 1 tumors in whom both dense adherence and large-volume ascites were absent. These patients are adequately treated by operation alone. Although the relapse risk was high enough in the remaining patients to warrant postoperative treatment, a significant benefit could be shown only for a small subset of patients, namely those with densely adherent tumors treated with abdominopelvic radiotherapy. In grades 2 and 3, none of the therapies used in either series was superior to pelvic radiotherapy or operation alone.

Colony-forming ability of human ovarian carcinomas in the Courtenay soft agar assay

One hundred and twenty-one ovarian carcinomas were cultivated in soft agar according to the Courtenay & Mills (C-M) soft agar method. 71% of the tumours formed colonies, and 54% formed more than 30 colonies. Tumour cells from malignant fluids grew more frequently than did solid tumours, whereas the plating efficiencies (PEs) were higher in the case of solid tumours. In general, the PEs were higher and more tumours formed colonies in the C-M method compared to the Hamburger-Salmon (H-S) method. The colony-forming ability did not show statistically significant correlation to histopathological type and grade, previous treatment and S-phase fraction, but was related to DNA ploidy. In poorly differentiated tumours a high colony-forming ability was associated with a poor prognosis, whereas the opposite was found in well and moderately differentiated tumours. Differential dose-response relationships were obtained after in vitro treatment with anticancer agents.

Influence of infusion time on unchanged cisplatin disposition in patients with ovarian cancer

The disposition of unchanged cisplatin in ten patients with ovarian cancer receiving 2-h infusions of 100 mg/m2 was compared with that of ten patients receiving 6-h infusions. A high-performance liquid chromatographic assay specific for the unchanged drug was used and all collected samples were rapidly processed. Patients were catheterized for urine collections. Cisplatin renal clearance was significantly lower after 6-hour infusions (52.8 +/- 16.2 ml/min per m2) than after 2-h infusions (87.1 +/- 38.2 ml/min per m2) (P = 0.026). Total clearance was also lower and less variable, although not significantly, in patients receiving the longer infusion. No differences in nonrenal clearance, volume of distribution, or half-life were observed between the two groups. There was only a poor relationship between cisplatin renal clearance and creatinine clearance after 2-h (r2 = 0.02; P = 0.66) and 6-h infusions (r2 = 0.18; P = 0.23). A single cisplatin plasma level obtained at the end of the infusion proved to be a good predictor of total cisplatin clearance after both 2-h (r2 = 0.70; P = 0.0096) and 6-h infusions (r2 = 0.97; P = 0.0001). This level was not significantly related to the relatively small changes in creatinine clearance that occurred after three courses of treatment.

Presynaptic beta-adrenoceptors in rat atria: evidence for the presence of stereoselective beta 1-adrenoceptors

1. Presynaptic beta-adrenoceptor activity was studied in rat isolated atria, previously loaded with [3H]-noradrenaline. The stimulation-induced release of 3H transmitter was measured in the presence of cocaine, and adrenaline was used as a facilitatory beta-adrenoceptor agonist. 2. Adrenaline (0.1 and 2 nM) increased, by about 50%, the evoked efflux of tritium. With phenoxybenzamine present, the same activity was shown with 10 nM adrenaline. 3. The beta 2-selective adrenoceptor blocking drugs: IPS 339 and ICI 118 551 caused a concentration-dependent decrease in the activity of adrenaline. Cardioselective beta-blocking drugs: acebutolol, beta-xolol, nebivolol and its isomers (R 67 138 and R 67 145) also reduced dose-dependently the agonistic action of adrenaline. The order of potency for nebivolol and its isomers was R 67 138 greater than nebivolol greater than R 67 145. The activity of pindolol was not concentration-dependent. The inhibitory effect of acebutolol was also observed in the presence of blockade of alpha-adrenoceptors. 4. The postsynaptic beta-adrenoceptor blocking activity of nebivolol and its isomers was studied in pithed rats. They reduced isoprenaline-induced tachycardia without altering hypotensive responses. The order of potency was: R 67 138 greater than nebivolol greater than R 67 145. 5. It is concluded that in rat isolated atria, presynaptic beta 2- and beta 1-adrenoceptors coexist and that facilitatory beta 1-adrenoceptors are stereospecific.