Effectiveness of monovalent COVID-19 booster/additional vaccine doses in the United States

Background

Monovalent booster/additional doses of COVID-19 vaccines were first authorized in August 2021 in the United States. We evaluated the real-world effectiveness of receipt of a monovalent booster/additional dose of COVID-19 vaccine compared with receiving a primary vaccine series without a booster/additional dose.

Methods

Cohorts of individuals receiving a COVID-19 booster/additional dose after receipt of a complete primary vaccine series were identified in 2 administrative insurance claims databases (Optum, CVS Health) supplemented with state immunization information system data between August 2021 and March 2022. Individuals with a complete primary series but without a booster/additional dose were one-to-one matched to boosted individuals on calendar date, geography, and clinical factors. COVID-19 diagnoses were identified in any medical setting, or specifically in hospitals/emergency departments (EDs). Propensity score-weighted hazards ratios (HRs) and 95% confidence intervals (CI) were estimated with Cox proportional hazards models; vaccine effectiveness (VE) was estimated as 1 minus the HR by vaccine brand overall and within subgroups of variant-specific eras, immunocompromised status, and homologous/heterologous booster status.

Results

Across both data sources, we identified 752,165 matched pairs for BNT162b2, 410,501 for mRNA-1273, and 11,398 for JNJ-7836735. For any medically diagnosed COVID-19, meta-analyzed VE estimates for BNT162b2, mRNA-1273, and JNJ-7836735, respectively, were: BNT162b2, 54% (95% CI, 53%-56%); mRNA-1273, 58% (95% CI, 56%-59%); JNJ-7836735, 34% (95% CI, 23%-44%). For hospital/ED-diagnosed COVID-19, VE estimates ranged from 70% to 76%. VE was generally lower during the Omicron era than the Delta era and for immunocompromised individuals. There was little difference observed by homologous or heterologous booster status.

Conclusion

The original, monovalent booster/additional doses were reasonably effective in real-world use among the populations for which they were indicated during the study period. Additional studies may be informative in the future as new variants emerge and new vaccines become available.Registration: The study protocol was publicly posted on the BEST Initiative website (https://bestinitiative.org/wp-content/uploads/2022/03/C19-VX-Effectiveness-Protocol_2022_508.pdf).

Compassionate Deactivation of Pediatric Ventricular Assist Devices: A Review of 14 Cases

CONTEXT

Compassionate deactivation (CD) of ventricular assist device (VAD) support is a recognized option for children when the burden of therapy outweighs the benefits.

OBJECTIVES

To describe the prevalence, indications, and outcomes of CD of children supported by VADs at the end of life.

METHODS

Review of cases of CD at our institution between 2011 and 2020. To distinguish CD from other situations where VAD support is discontinued, patients were excluded from the study if they died during resuscitation (including extracorporeal membrane oxygenation), experienced brain or circulatory death prior to deactivation, or experienced a non-survivable brain injury likely to result in imminent death regardless of VAD status.

RESULTS

Of 24 deaths on VAD, 14 (58%) were CD. Median age was 5.7 (interquartile range (IQR) 0.6, 11.6) years; 6 (43%) had congenital heart disease; 4 (29%) were on a device that can be used outside of the hospital. CD occurred after 40 (IQR: 26, 75) days of support; none while active transplant candidates. CD discussions were initiated by the caregiver in 6 (43%) cases, with the remainder initiated by a medical provider. Reasons for CD were multifactorial, including end-organ injury, infection, and stroke. CD occurred with endotracheal extubation and/or discontinuation of inotropes in 12 (86%) cases, and death occurred within 10 (IQR: 4, 23) minutes of CD.

CONCLUSION

CD is the mode of death in more than half of our VAD non-survivors and is pursued for reasons primarily related to noncardiac events. Caregivers and providers both initiate CD discussions. Ventilatory and inotropic support is often withdrawn at time of CD with ensuing death.

Identification of citrus immune regulators involved in defence against Huanglongbing using a new functional screening system

Huanglongbing (HLB) is the most devastating citrus disease in the world. Almost all commercial citrus varieties are susceptible to the causal bacterium, Candidatus Liberibacter asiaticus (CLas), which is transmitted by the Asian citrus psyllid (ACP). Currently, there are no effective management strategies to control HLB. HLB-tolerant traits have been reported in some citrus relatives and citrus hybrids, which offer a direct pathway for discovering natural defence regulators to combat HLB. Through comparative analysis of small RNA profiles and target gene expression between an HLB-tolerant citrus hybrid (Poncirus trifoliata × Citrus reticulata) and a susceptible citrus variety, we identified a panel of candidate defence regulators for HLB-tolerance. These regulators display similar expression patterns in another HLB-tolerant citrus relative, with a distinct genetic and geographic background, the Sydney hybrid (Microcitrus virgata). Because the functional validation of candidate regulators in tree crops is always challenging, we developed a novel rapid functional screening method, using a C. Liberibacter solanacearum (CLso)/potato psyllid/Nicotiana benthamiana interaction system to mimic the natural transmission and infection circuit of the HLB complex. When combined with efficient virus-induced gene silencing in N. benthamiana, this innovative and cost-effective screening method allows for rapid identification and functional characterization of regulators involved in plant immune responses against HLB, such as the positive regulator BRCA1-Associated Protein, and the negative regulator Vascular Associated Death Protein.

The chromatin-remodeling protein BAF60/SWP73A regulates the plant immune receptor NLRs

In both plant and animal innate immune responses, surveillance of pathogen infection is mediated by membrane-associated receptors and intracellular nucleotide-binding domain and leucine-rich-repeat receptors (NLRs). Homeostasis of NLRs is under tight multilayered regulation to avoid over-accumulation or over-activation, which often leads to autoimmune responses that have detrimental effects on growth and development. How NLRs are regulated epigenetically at the chromatin level remains unclear. Here, we report that SWP73A, an ortholog of the mammalian switch/sucrose nonfermentable (SWI/SNF) chromatin-remodeling protein BAF60, suppresses the expression of NLRs either directly by binding to the NLR promoters or indirectly by affecting the alternative splicing of some NLRs through the suppression of cell division cycle 5 (CDC5), a key regulator of RNA splicing. Upon infection, bacteria-induced small RNAs silence SWP73A to activate a group of NLRs and trigger robust immune responses. SWP73A may function as a H3K9me2 reader to enhance transcription suppression.

Effectiveness of risk minimization measures for the use of cilostazol in United Kingdom, Spain, Sweden, and Germany

Purpose

The purpose of the study is to evaluate the effectiveness of risk minimization measures—labeling changes and communication to health care professionals—recommended by the European Medicines Agency for use of cilostazol for the treatment of intermittent claudication in Europe.

Methods

Observational study of cilostazol in The Health Improvement Network (United Kingdom), EpiChron Cohort (Spain), SIDIAP (Spain), Swedish National Databases, and GePaRD (Germany).

Among new users of cilostazol, we compared the prevalence of conditions targeted by the risk minimization measures in the periods before (2002‐2012) and after (2014) implementation. Conditions evaluated were prevalence of smoking, cardiovascular conditions, concurrent use of ≥2 antiplatelet agents, concurrent use of potent CYP3A4/CYP2C19 inhibitors and high‐dose cilostazol, early monitoring of all users, and continuous monitoring of users at high cardiovascular risk.

Results

We included 22 593 and 1821 new users of cilostazol before and after implementation of risk minimization measures, respectively. After implementation, the frequency of several conditions related to the labeling changes improved in all the study populations: prevalence of use decreased between 13% (EpiChron) and 57% (SIDIAP), frequency of cardiovascular contraindications decreased between 8% (GePaRD) and 84% (EpiChron), and concurrent use of high‐dose cilostazol and potent CYP3A4/CYP2C19 inhibitors decreased between 6% (Sweden) and 100% (EpiChron). The frequency of other conditions improved in most study populations, except smoking, which decreased only in EpiChron (48% reduction).

Conclusions

This study indicates that the risk minimization measures implemented by the EMA for the use of cilostazol have been effective in all European countries studied, except for smoking cessation before initiating cilostazol, which remains an area of improvement.

Airway Remodeling and Hyperreactivity in a Model of Bronchopulmonary Dysplasia and Their Modulation by IL-1 Receptor Antagonist

Bronchopulmonary dysplasia (BPD) is a chronic disease of extreme prematurity that has serious long-term consequences including increased asthma risk. We earlier identified IL-1 receptor antagonist (IL-1Ra) as a potent inhibitor of murine BPD induced by combining perinatal inflammation (intraperitoneal LPS to pregnant dams) and exposure of pups to hyperoxia (fraction of inspired oxygen = 0.65). In this study, we determined whether airway remodeling and hyperresponsiveness similar to asthma are evident in this model, and whether IL-1Ra is protective. During 28-day exposure to air or hyperoxia, pups received vehicle or 10 mg/kg IL-1Ra by daily subcutaneous injection. Lungs were then prepared for histology and morphometry of alveoli and airways, or for real-time PCR, or inflated with agarose to prepare precision-cut lung slices to visualize ex vivo intrapulmonary airway contraction and relaxation by phase-contrast microscopy. In pups reared under normoxic conditions, IL-1Ra treatment did not affect alveolar or airway structure or airway responses. Pups reared in hyperoxia developed a severe BPD-like lung disease, with fewer, larger alveoli, increased subepithelial collagen, and increased expression of α-smooth muscle actin and cyclin D1. After hyperoxia, methacholine elicited contraction with similar potency but with an increased maximum reduction in lumen area (air, 44%; hyperoxia, 89%), whereas dilator responses to salbutamol were maintained. IL-1Ra treatment prevented hyperoxia-induced alveolar disruption and airway fibrosis but, surprisingly, not the increase in methacholine-induced airway contraction. The current study is the first to demonstrate ex vivo airway hyperreactivity caused by systemic maternal inflammation and postnatal hyperoxia, and it reveals further preclinical mechanistic insights into IL-1Ra as a treatment targeting key pathophysiological features of BPD.

Docetaxel chemotherapy in metastatic castration-resistant prostate cancer: cost of care in Medicare and commercial populations

OBJECTIVE

To estimate the healthcare costs and characteristics of docetaxel chemotherapy episodes of care for men with metastatic castration-resistant prostate cancer (mCRPC).

METHODS

This study used the Medicare 5% sample and MarketScan Commercial (2010-2013) claims data sets to identify men with mCRPC and initial episodes of docetaxel treatment. Docetaxel episodes included docetaxel claim costs from the first claim until 30 days after the last claim, with earlier termination for death, insurance disenrollment, or the end of a 24-month look-forward period from initial docetaxel index date. Docetaxel drug claim costs were adjusted for 2011 generic docetaxel introduction, while other costs were adjusted to 2015 values using the national average annual unit cost increase.

RESULTS

This study identified 281 Medicare-insured and 155 commercially insured men, with 325 and 172 docetaxel episodes, respectively. The average number of cycles (unique docetaxel infusion days) per episode was 6.9 for Medicare and 6.3 for commercial cohorts. The average cost per episode was $28,792 for Medicare and $67,958 for commercial cohorts, with docetaxel drug costs contributing $2,588 and $13,169 per episode, respectively. The average cost per episode on docetaxel infusion days was $8,577 (30%) for Medicare and $28,412 (42%) for commercial. Non-docetaxel infusion day costs included $7,074 (25%) for infused or injected drugs for Medicare, $10,838 (16%) for commercial cohorts, and $6,875 (24%) and $9,324 (14%) for inpatient admissions, respectively.

LIMITATIONS

The applicability is only to the metastatic castration-resistance clinical setting, rather than the metastatic hormone-sensitive setting, and the lack of data on the cost effectiveness of different sequencing strategies of a range of systemic therapies including enzalutamide, abiraterone, radium-223, and taxane chemotherapy.

CONCLUSION

The majority of docetaxel episode costs in Medicare and commercial mCRPC populations were non-docetaxel drug costs. Future research should evaluate the total cost of care in mCPRC.

Characterization of new users of cilostazol in the UK, Spain, Sweden, and Germany

Purpose

To describe the characteristics of new users of cilostazol in Europe with the aim to support the evaluation of its benefit/risk as used in regular clinical practice before the implementation of labeling changes recommended by the European Medicines Agency.

Methods

New users of cilostazol were identified in populations enrolled in five European health automated databases in the UK (The Health Improvement Network [THIN]), Spain (EpiChron cohort and Information System for the Improvement of Research in Primary Care [SIDIAP]), Sweden (National Registers), and Germany (German Pharmacoepidemiological Research Database [GePaRD]) between 2002 and 2012. New users were characterized according to the prevalence of cardiovascular disease and other comorbidities, concurrent use of interacting medications, new contraindications, duration of use, and potential off‐label prescribing.

Results

We identified 22 593 new users of cilostazol. The median age was between 68.0 (THIN) and 73.7 (Sweden) years. More than 78% of users had concomitant cardiovascular disease, and between 78.8% (GePaRD) and 91.6% (THIN) were treated with interacting medications. Prevalence of new cardiovascular contraindications ranged from 1.5% (THIN) to 11.6% (GePaRD), and concurrent use of two or more antiplatelet drugs ranged from 6.3% (SIDIAP) to 13.5% (EpiChron cohort). Between 39.4% (Sweden) and 52.9% (THIN) of users discontinued cilostazol in the first 3 months. Between 41.0% (SIDIAP) and 93.4% (THIN) were considered to have received cilostazol according to the European Medicines Agency labeling.

Conclusions

In this collaborative European study, most cilostazol users were elderly patients with a high prevalence of cardiovascular diseases and other comorbidity and concurrent use of interacting drugs, indicating that this is a vulnerable population at high risk of complications, especially cardiovascular events. © 2017 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.

Antimicrobial stewardship programs that target only high-cost, broad-spectrum antimicrobials miss opportunities to reduce Clostridium difficile infections

Antimicrobial stewardship programs are promoted as a strategy to reduce Clostridium difficile infections. We implemented an antimicrobial stewardship program comprised of formulary restriction plus prospective audit with feedback for high-cost and broad-spectrum antimicrobials. Subsequently, we reviewed all heath care facility-onset, health care facility-associated C difficile infections. We found that most of these infections were associated with the antecedent receipt of nonaudited, and often unnecessary, antimicrobials.

Patient preferences for attributes of multiple sclerosis disease-modifying therapies: development and results of a ratings-based conjoint analysis

BACKGROUND

Timely individualized treatment is essential to improving relapsing-remitting multiple sclerosis (RRMS) patient health outcomes, yet little is known about how patients make treatment decisions. We sought to evaluate RRMS patient preferences for risks and benefits of treatment.

METHODS

Fifty patients with RRMS completed conjoint analysis surveys with 16 hypothetical disease-modifying therapy (DMT) medication profiles developed using a fractional factorial design. Medication profiles were assigned preference ratings from 0 (not acceptable) to 10 (most favorable). Medication attributes included a range of benefits, adverse effects, administration routes, and market durations. Analytical models used linear mixed-effects regression.

RESULTS

Participants showed the highest preference for medication profiles that would improve their symptoms (β = 0.81-1.03, P < .001), not a proven DMT outcome. Preventing relapses, the main clinical trial outcome, was not associated with significant preferences (P = .35). Each year of preventing magnetic resonance imaging changes and disease symptom progression showed DMT preferences of 0.17 point (β = 0.17, P = .002) and 0.12 point (β = 0.12, P < .001), respectively. Daily oral administration was preferred over all parenteral routes (P < .001). A 1% increase in death or severe disability decreased relative DMT preference by 1.15 points (P < .001).

CONCLUSIONS

Patient preference focused on symptoms and prevention of progression but not on relapse prevention, the proven drug outcome. Patients were willing to accept some level of serious risk for certain types and amounts of benefits, and they strongly preferred daily oral administration over all other options.

Patient centered decision making: use of conjoint analysis to determine risk-benefit trade-offs for preference sensitive treatment choices

Understanding patient preferences facilitates shared decision-making and focuses on patient-centered outcomes. Little is known about relapsing-remitting multiple sclerosis (RRMS) patient preferences for disease modifying therapies (DMTs). We use choice based conjoint (CBC) analysis to calculate patient preferences for risk/benefit trade-offs for hypothetical DMTs.

METHODS

Patients with RRMS were surveyed between 2012 and 2013. Our CBC survey mimicked the decision-making process and trade-offs of patients choosing DMTs, based on all possible DMT attributes. Mixed-effects logistic regression analyzed preferences. We estimated maximum acceptable risk trade-offs for various DMT benefits.

RESULTS

Severe side-effect risks had the biggest impact on patient preference with a 1% risk, decreasing patient preference five-fold compared to no risk. (OR=0.22, p<0.001). Symptom improvement was the most preferred benefit (OR=3.68, p<0.001), followed by prevention of progression of 10 years (OR=2.4, p<0.001). Daily oral administration had the third highest DMT preference rating (OR=2.08, p<0.001). Patients were willing to accept 0.08% severe risk for a year delayed relapse, and 0.22% for 4 vs 2 year prevented progression.

CONCLUSION

We provided patient preferences and risk-benefit trade-offs for attributes of all available DMTs. Evaluation of patient preferences is a key step in shared decision making and may significantly impact early drug initiation and compliance.

[Advanced uterine prolapse during pregnancy: pre- and postnatal management]

Pelvic organ prolapse is a common pelvic floor disorder in postmenopausal women. The literature is quite poor concerning the management of prolapse during pregnancy in young women. We report the case of a 39-year-old multiparous woman referred for the treatment of an exteriorized uterine prolapse at 13 weeks of gestation. The management of cervical prolapse depends on its stage, its evolution and on gestational age. It combines local antiseptics, rest and manual reintegration or reduction of the prolapsus using a pessary to prevent ulceration of the cervix. In case of stage IV (POP-Q) uterine prolapse, vaginal delivery may be compromised. No recommendation is actually available about route of delivery in case of exteriorized uterine prolapse. It should be clearly discussed regarding the potential risk of cesarean section for dystocia. Surgical repair of the prolapse will be discussed after childbirth according to functional impairment and women's desire for pregnancy.

Epigenetic mechanisms in cartilage and osteoarthritis: DNA methylation, histone modifications and microRNAs

Osteoarthritis (OA) is a complex multifactorial disease with a strong genetic component. Several studies have suggested or identified epigenetic events that may play a role in OA progression and the gene expression changes observed in diseased cartilage. The aim of this review is to inform about current research in epigenetics and epigenetics in OA. Epigenetic mechanisms include DNA methylation, histone modifications, and microRNAs. Collectively, these enable the cell to respond quickly to environmental changes and can be inherited during cell division. However, aberrant epigenetic modifications are associated with a number of pathological conditions, including OA. Advancements in epigenetic research suggests that global analysis of such modifications in OA are now possible, however, with the exception of microRNAs, it will be a significant challenge to demonstrate how such events impact on the disease.

[Functional results and quality of life of laparoscopic promontofixation in the cure of genital prolapse]

OBJECTIVE

To evaluate the feasibility and morbidity of laparoscopic promontofixation in the cure of genital prolapse.

PATIENTS AND METHOD

From March 2001 to January 2009, 101 patients with genital prolapse of grade greater than or equal to 2 (POPQ classification) were operated by laparoscopy. Complications per and postoperative as well as patient satisfaction were assessed. Quality of life was evaluated using the questionnaires Pelvic Floor Distress Inventory (PFDI 20), Pelvic Floor Impact Questionnaire (PISQ 7) and Pelvic Organ Prolaps/Urinary Incontinence Sexual Questionnaire (PISQ 12).

RESULTS

The mean operative time was 196 min including the time for hysterectomy done in 83% of cases. The peroperative complication rate was 7% including two bladder and one rectal injuries and 4% of laparoconversion. The postoperative complication rate was 16% corresponding to 3/4 of retention of urine. Two pelvic hematomas were observed. The distance complication rate was 3% corresponding to a vaginal erosion, a spondylodiscitis and a case of persistent pelvic pain requiring removal of material. With a mean follow-up of 30.7 months, 81% patients declared themselves satisfied with the intervention. In intention to treat, the satisfaction rate was only 67.3%. A significant improvement in quality of life was observed using the questionnaire PFDI 20 (p < 0.0001), PFIQ 7 (p < 0.0001) et PISQ 12 (p < 0.001).

DISCUSSION AND CONCLUSION

Our results confirm the feasibility of the laparoscopic promontofixation with a quality of life improvement but also highlights the existence of significant morbidity requiring further trials for the choice of surgical approach for the treatment of genital prolapse.

Colorectal cancer patient utilization of an internet based clinical trials matching system

3624

Background: Colorectal cancer patients are increasingly looking to the Internet for information on clinical trials; however, services offering clinical trials recruitment have not been well defined. This study describes one of the first web-based cancer clinical trials matching resources and the demographics of the colorectal cancer patient user base. Methods: Oncolink ( http://www.oncolink.org ) is the web-based educational resource at the University of Pennsylvania and serves between 1.5–2 million pages per month to over 385,000 unique IP addresses. Oncolink, in conjunction with EmergingMed (New York, NY), launched one of the first clinical trials matching resources on the Internet. Patients input demographic and tumor-specific information via secure Internet-only registration or via the Internet with assistance from a call center, to match to trials. As of 12/2005, there were 112 total colorectal trials in the database. Results: Between 12/2000 and 9/2005 a total of 41,970 individual profiles were created, with 3289 (7.8%) by colorectal cancer patients. Other GI tumors accounted for 15% of profiles. Of the 3289 patients, 54% were male and 46% were female, and the median age was 55 (range 19–96). Most patients reported their disease as having spread to another organ (62%) or to lymph nodes (15.4%). Most patients were previously treated with surgery (81%), radiation (26%), chemotherapy (74%), and/or biological therapies (21%) (bevacizumab, cetuximab, interferon or interleukin). Patients who used the call center with the Internet were more likely to apply for enrollment in a clinical trial after review of the matches (77% vs. 10%, p<0.001). The median number of trial matches in the system was 7 per patient. Of the 3289 colorectal patients, 681 patients (21%) went on to apply for enrollment to trials based on their matches. Conclusions: This report demonstrates that a significant percentage of colorectal cancer patients are willing to use the Internet to match to clinical trials. Contact with a call center greatly increases the likelihood of application to trials. Internet based clinical trials resources should maintain options for personal communication to increase the likelihood of enrollment to clinical trials.

No significant financial relationships to disclose.

Comparison of new clinical and scintigraphic algorithms for the diagnosis of pulmonary embolism

Since the publication of the modified Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) criteria for the diagnosis of pulmonary embolism (PE), new clinical and scintigraphic diagnostic algorithms (the McMaster clinical criteria, the PisaPED simplified scintigraphic grading and the Miettinen logistic regression analysis) have been reported although the results have not been reproduced in other sites. Ventilation-perfusion lung scintigraphy was performed in 238 consecutive patients with a provisional diagnosis of PE. Scans were reported as normal/very low, low, intermediate or high probability for PE using standardized criteria. Each patient received a clinical grading of probability of PE as low, moderate or high using the McMaster clinical criteria. Using the PisaPED criteria (an alternate simplified scintigraphic grading system using the perfusion scan alone) each scan was also graded as normal/near normal, abnormal but not PE, or abnormal and PE. Using the logistic regression algorithm of Miettinen each scan received a numerical probability of PE. Frequencies for differing levels of probability of PE varied widely between the various algorithms. Cross tabulations revealed correlation of the standardized criteria with the Miettinen grading but not with the McMaster or the PisaPED gradings. We were unable to reproduce similar results using the McMaster clinical grading or the PisaPED simplified scintigraphic grading although the Miettinen logistic regression formula gave comparable results. New algorithms are not automatically transferable to new environments.

Estramustine in combination with vinblastine and mitomycin-C for patients with progressive androgen independent adenocarcinoma of the prostate

A phase II trial was performed to assess the antitumor activity and toxicity of estramustine in combination with vinblastine and mitomycin-C in 46 consecutive patients with androgen independent prostate cancer. All patients presented with disease progression following castrate serum testosterone levels and were treated for six consecutive weeks with three daily 140 mg doses of oral estramustine, vinblastine at 5 mg/m(2) weekly by intravenous bolus and mitomycin-C at 15 mg/m(2) every six weeks by intravenous bolus. Prostate specific antigen levels decreased by greater than 50% from baseline in 16 (41%; 95% CI 25-58%) and normalized in 11 (28%; 95% CI 14-45%) of 39 evaluable patients. Patients who demonstrated a greater than 50% reduction in PSA had a longer delay in time to disease progression. Non-hematologic toxicity was mild, predominately gastrointestinal. Hematologic toxicity was apparent in five patients with Grade III granulocytopenia and in 21 patients with Grade IV granulocytopenia of 43 evaluable patients for toxicity. Three patients were admitted to the hospital for neutropenic fever. Eight patients had Grade III thrombocytopenia, four patients had Grade IV thrombocytopenia, no bleeding occurred. Estramustine in combination with vinblastine and mitomycin-C is an active regimen. The non-hematologic toxicity was tolerable, while the hematologic toxicity required individual dosage reduction. The combination and the clinical significance of the decline in the PSA warrants further investigation.

Influence of centrifugation on the infectivity of Chlamydia pneumoniae IOL-207

The influence of centrifugation on the infectivity of Chlamydia pneumoniae IOL-207 was compared with seven serovars of C. trachomatis biovar trachoma, the three serovars of C. trachomatis biovar lymphogranuloma and four C. psittaci strains. Prolonged centrifugation from 1 to 4 hours resulted in a 3-fold increase in the infectivity of C. pneumoniae and variable or no increase in the infectivity of the other Chlamydia strains studied. These findings indicate that a 4 hour centrifugation of C. pneumoniae is recommended to improve the isolation procedures of this organism in cell cultures.

Enzymatic characterization of immunopurified prohormone convertase 2: potent inhibition by a 7B2 peptide fragment

Prohormone convertase (PCs) are thought to mediate the controlled proteolysis of prohormones and neuropeptide precursors. While recombinant PC1 and furin are currently available, thus far it has not been possible to produce recombinant PC2. We have used conditioned medium obtained from the mouse insulinoma cell line beta TC3 to generate a working preparation of enzymatically active PC2 through immunopurification. Immunopurified PC2 cleaved the fluorogenic substrate Cbz-Arg-Ser-Lys-Arg-AMC in a time- and calcium-dependent manner. It was half-maximally stimulated at 75 microM Ca2+, had an optimum pH of 5, and exhibited PCMS and EDTA sensitivity similar to that reported for furin and PC1. The tight-binding inhibitor 27 kDa 7B2 was used to calculate the Kd for this inhibitor and the active enzyme concentration. The Kd was 7.3 +/- 1.7 nM, and the turnover rate of PC2 was 5.2 molecules substrate per enzyme molecule per minute. The specific activity was 4.9 nmol/micrograms/h (assuming a molecular mass for PC2 of 64 kDa). The enzyme preparation was able to cleave recombinant proenkephalin at at least four of the expected paired basic sites in the absence, but not in the presence, of 27 kDa 7B2. Since 21 kDa 7B2 is functionally inactive as a proteinase inhibitor, we examined the inhibitory activity of the carboxy-terminal portion of 27 kDa 7B2 (7B2 CT-peptide). Synthetic peptides were used to demonstrate that the 7B2 CT-peptide (a) represents a potent inhibitor of PC2 (Ki = 57 nM), (b) can block the conversion of proPC2 to PC2, and (c) can block the PC2-mediated conversion of proenkephalin to smaller peptide fragments.(ABSTRACT TRUNCATED AT 250 WORDS)

Phase II study of ketoconazole combined with weekly doxorubicin in patients with androgen-independent prostate cancer

PURPOSE

A phase II clinical trial was performed to assess the antitumor activity and toxicity of ketoconazole in combination with doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH) in patients with androgen-independent prostate cancer (AI PCa).

PATIENTS AND METHODS

Thirty-nine consecutive patients whose disease progressed following castration were treated with oral ketoconazole (1,200 mg) daily and Adriamycin (20 mg/m2 in a 24-hour infusion) once weekly. Antitumor activity was assessed by the level of prostatic-specific antigen (PSA) decline.

RESULTS

PSA levels decreased > or = 50% from baseline in 21 (55%; 95% confidence interval, 38% to 71%) of 38 assessable patients. We observed partial responses (PRs) in seven (58%) of 12 patients with measurable soft tissue disease (in the lung, lymph nodes, and liver). Two patients with history of atherosclerotic heart disease had a sudden cardiac death. Serious toxic reactions included grade III to V stomatitis and grade III to IV acral erythema in 11 patients (29%), and grade III to IV anal and urethral mucositis in five patients (13%). Grade III to IV neutropenia occurred in 11 patients (29%). Seventeen patients (45%) required hospitalization for complications. Fifteen patients (39%) developed hypokalemia, and 24 patients (63%) developed clinical adrenal insufficiency.

CONCLUSION

The combination of ketoconazole and Adriamycin has a 55% PSA response rate in patients with AI PCa and is worthy of additional study. This treatment results in frequent adrenal insufficiency. Therefore, future studies should incorporate routine corticosteroid replacement. The cardiac complications caused by this combination should be studied further before it is widely used.

Progesterone receptor heterogeneity and endometrial tumour differentiation

Progesterone binding components were isolated using fast protein liquid chromatography (FPLC) with a recovery efficiency of between 60-70%. In normal uterine cytosol, the two components were in about equal proportions. In endometrial cancer, the ratio of peak size between peaks 1 and 2 was 1.5 for Grade I, 3.7 for Grade II and 2.5 for Grade III. Whether estimation of the levels of the two progesterone components separately would enhance predictability of response to hormone therapy in endometrial cancer remains to be established.