Meta-Analysis of Quality of Life in Cancer Patients Treated with Immune Checkpoint Inhibitors

BACKGROUND

Trials of immune checkpoint inhibitors (ICIs) have published patient-reported quality of life (QOL), but the size and heterogeneity of this literature can make patient education difficult. This meta-analysis aimed to describe change in QOL and symptomatology in patients receiving ICIs for cancer.

METHODS

Following PRISMA guidelines, databases were searched through November 2019 for articles or abstracts of prospective, original studies reporting longitudinal QOL in adult cancer patients treated with ICIs. The prespecified primary outcomes were change in global QOL among patients treated with ICIs and difference in change since baseline in global QOL between patients treated with ICI vs. non-ICI active treatment. Secondary outcomes included physical functioning and symptomatology. All statistical tests were 2-sided.

RESULTS

Twenty-six of 20,323 publications met inclusion criteria. Global QOL did not change over time in patients treated with ICIs (k = 26, n = 6,974, P = .19). Larger improvements in global QOL was observed in patients receiving ICI vs. non-ICI regimens (k = 16, ICI n = 3,588, non-ICI n = 2,948, P < .001). Physical functioning did not change in patients treated with ICIs (k = 14, n = 3,169, P=.47); there were no differences in mean change between ICI vs. non-ICI regimens (k = 11, n = 4,630, P=.94. Regarding symptoms, appetite loss, insomnia, and pain severity decreased but dyspnea severity increased in patients treated with ICIs (k = 14, n = 3,243-3,499) (Ps < 0.001). Insomnia severity was higher in patients treated with ICIs than non-ICI regimens (k = 11, n = 4,791) (P < .001).

CONCLUSIONS

This study is among the first to quantitatively summarize QOL in patients treated with ICIs. Findings suggest ICI recipients report no change in global QOL and higher QOL than patients treated with non-ICI regimens.

A phase IB clinical trial of 15 Gy HDR brachytherapy followed by hypofractionated/SBRT in the management of intermediate-risk prostate cancer

PURPOSE

High dose-rate (HDR) brachytherapy is commonly administered as a boost to external beam radiation therapy (EBRT). Our purpose was to compare toxicity with increasingly hypofractionated EBRT in combination with a single 15 Gy HDR boost for men with intermediate-risk prostate cancer.

METHODS AND MATERIALS

Forty-two men were enrolled on this phase IB clinical trial to one of three EBRT dose cohorts: 10 fractions, seven fractions, or five fractions. Patients were followed prospectively for safety, efficacy, and health-related quality of life (Expanded Prostate Index Composite). Efficacy was assessed biochemically using the Phoenix definition.

RESULTS

With a median follow up of 36 months, the biochemical disease-free survival was 95.5%. One man developed metastatic disease at 5 years. There was no significant minimally important difference in EPIC PRO for either urinary, bowel, or sexual domains. There was one acute Grade 3 GI and GU toxicity, but no late Grade 3 GU or GI toxicities.

CONCLUSION

Fifteen gray HDR brachytherapy followed by a five fraction SBRT approach results in high disease control rates and low toxicity similar to previously reported HDR protocols with significant improvement in patient convenience and resource savings. While mature results with longer follow up are awaited, this treatment approach may be considered a safe and effective option for men with intermediate-risk disease.

Clinical Integration of Digital Solutions in Health Care: An Overview of the Current Landscape of Digital Technologies in Cancer Care

Digital health constitutes a merger of both software and hardware technology with health care delivery and management, and encompasses a number of domains, from wearable devices to artificial intelligence, each associated with widely disparate interaction and data collection models. In this review, we focus on the landscape of the current integration of digital health technology in cancer care by subdividing digital health technologies into the following sections: connected devices, digital patient information collection, telehealth, and digital assistants. In these sections, we give an overview of the potential clinical impact of such technologies as they pertain to key domains, including patient education, patient outcomes, quality of life, and health care value. We performed a search of PubMed ( www.ncbi.nlm.nih.gov/pubmed ) and www.ClinicalTrials.gov for numerous terms related to digital health technologies, including digital health, connected devices, smart devices, wearables, activity trackers, connected sensors, remote monitoring, electronic surveys, electronic patient-reported outcomes, telehealth, telemedicine, artificial intelligence, chatbot, and digital assistants. The terms health care and cancer were appended to the previously mentioned terms to filter results for cancer-specific applications. From these results, studies were included that exemplified use of the various domains of digital health technologies in oncologic care. Digital health encompasses the integration of a vast array of technologies with health care, each associated with varied methods of data collection and information flow. Integration of these technologies into clinical practice has seen applications throughout the spectrum of care, including cancer screening, on-treatment patient management, acute post-treatment follow-up, and survivorship. Implementation of these systems may serve to reduce costs and workflow inefficiencies, as well as to improve overall health care value, patient outcomes, and quality of life.

Treatment patterns and disease outcomes for pediatric patients with refractory or recurrent Hodgkin lymphoma treated with curative-intent salvage radiotherapy

BACKGROUND AND PURPOSE

The use of radiotherapy (RT) for pediatric patients with Hodgkin lymphoma (HL) experiencing disease progression or recurrence (15%) is controversial. We report treatment patterns and outcomes for pediatric patients with refractory/recurrent HL (rrHL) treated with curative-intent RT.

MATERIALS AND METHODS

Forty-six patients with rrHL treated with salvage RT at our institution were identified. All received risk-adapted, response-based frontline therapy and were retrieved with cytoreductive regimens followed by RT to failure sites, with or without autologous hematopoietic cell transplantation (AHCT). Cumulative incidence (CIN) of local failure (LF) and survival were estimated after salvage RT and regression models determined predictors of LF after salvage RT.

RESULTS

RT was administered as part of frontline therapy in 70% of patients, omitted for early response assessment in 13%, or deferred for primary progression in 17%. AHCT was omitted in 20% of patients. Median initial and salvage dose/site were 25.5 Gy and 30.6 Gy, respectively. Eight patients experienced progression. Two died without progression (median follow-up from salvage RT = 3.8 years). The 5-year CIN of LF after salvage RT was 17.7% (95% confidence interval [CI], 8.2-30.2%). The 5-year freedom from subsequent treatment failure and overall survival (OS) was 80.1% (95% CI, 69.2-92.6%) and 88.5% (95% CI, 79.5-98.6%), respectively. Inadequate response to salvage systemic therapy (p = 0.048) and male sex (p = 0.049) were significantly associated with LF after salvage RT.

CONCLUSION

rrHL is responsive to salvage RT, with low LF rates after moderate doses. OS is excellent, despite refractory disease. Initial salvage therapy response predicts subsequent LF.

The effect of non-steroidal anti-inflammatory drugs on osteosarcoma cells

OBJECTIVE

Osteosarcoma (OS), an aggressive malignancy, is the most common primary bone tumor in children. Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to reduce pain and inflammation. NSAIDs have shown to be toxic to certain malignancies such as colorectal, breast, and pancreatic cancers, but are not well-studied in OS. The purpose of this study is to assess whether ketorolac induces apoptosis in OS cells, compare this to indomethacin, which has been shown to inhibit OS proliferation, and explore the underlying mechanism.

MATERIALS AND METHODS

A rat OS cell line (UMR-108) was exposed to various concentrations of ketorolac and indomethacin. Cell viability, cytotoxicity, apoptosis induction, DNA fragmentation and the expression of apoptosis-related markers were examined by MTT assay, colony formation assay, flow cytometry, agarose gel electrophoresis, and Western blot respectively.

RESULTS

The results indicated that ketorolac and indomethacin could induce apoptosis of rat OS cells in a dose- and time-dependent manner. Apoptosis was confirmed by cell morphology and annexin positivity. The molecular data showed that NSAIDs affected expression of Bcl-2, survivin, and Poly (ADP-ribose) polymerase-1 (PARP).

CONCLUSIONS

These findings demonstrated that NSAIDs induced apoptosis in rat OS cells in vitro. Further research focusing on the potential cytotoxicity of NSAIDs in vivo is needed.

Sleep disturbance in men receiving androgen deprivation therapy for prostate cancer: The role of hot flashes and nocturia

BACKGROUND

Patients with prostate cancer receiving androgen deprivation therapy (ADT) are at risk of sleep disturbance; however, to the authors' knowledge, the mechanisms by which ADT may affect sleep are not well understood. The current study compared objective and subjective sleep disturbance in ADT recipients and controls and examined whether sleep disturbance in ADT recipients is attributable to the influence of ADT on hot flashes and nocturia.

METHODS

Patients with prostate cancer were assessed before or within 1 month after the initiation of ADT as well as 6 months and 12 months later (78 patients). Patients with prostate cancer were treated with prostatectomy only (99 patients) and men with no history of cancer (108 men) were assessed at similar intervals. Participants self-reported their sleep disturbance (Insomnia Severity Index) and interference from hot flashes (Hot Flash Related Daily Interference Scale). One hundred participants also wore actigraphs for 3 days at the 6-month assessment to measure objective sleep disturbance and reported their nocturia frequency.

RESULTS

ADT recipients reported worse sleep disturbance, higher rates of clinically significant sleep disturbance, and greater hot flash interference than controls (Ps≤.03). In cross-sectional analyses among those with actigraphy data, ADT recipients had greater objective sleep disturbance and more episodes of nocturia (Ps<.01). Cross-sectional mediation analyses demonstrated that the association between ADT and objectively and subjectively measured sleep disturbance was partly attributable to nocturia and hot flashes (Ps<.05).

CONCLUSIONS

The results of the current study suggest that the association between ADT and sleep may be partly explained by nocturia and hot flash interference. Future studies should examine behavioral and pharmacologic interventions to address these symptoms among ADT recipients. Cancer 2018;124:499-506. © 2017 American Cancer Society.

The Role of Genomic Techniques in Predicting Response to Radiation Therapy

The understanding of the relationship between genetic variation and an individual patient's response to radiation therapy (RT) has gained significant ground over the past several years. Genetic markers have been identified that could ultimately serve as the foundation for predictive models in clinical practice, and that hold the potential to revolutionize the delivery of precision medicine in oncology. Single nucleotide polymorphisms, single genes, and/or gene signatures could ultimately serve as the basis for patient stratification in prospective clinical trials. Currently, molecular markers relevant to breast, lung, and head and neck cancers have been integrated into clinical practice and serve as predictive tools to guide systemic therapy. In the future, the use of predictive models based on genomic determinants may become standard practice in radiation oncology, offering the potential to further personalize the delivery of RT and optimize the therapeutic ratio.

Management of Stage I Lung Cancer with Stereotactic Ablative Radiation Therapy

Early stage non-small cell lung cancer is a growing clinical entity with evolving standards of care. With the adoption of lung screening guidelines, the incidence of early stage disease is expected to increase. Surgical resection for early stage disease has been considered standard of care; however, there is evidence that stereotactic ablative radiation therapy (SABR) may be a viable alternate to surgery. In the last decade, advances in image guidance, treatment planning systems, and improved spatial accuracy of treatment delivery have converged to result in the effective use of SABR in the treatment of early stage lung cancer.

Phase 1 Study of Ipilimumab Combined With Whole Brain Radiation Therapy or Radiosurgery for Melanoma Patients With Brain Metastases

PURPOSE

We performed a phase 1 study to determine the maximum tolerable dose and safety of ipilimumab with stereotactic radiosurgery (SRS) or whole brain radiation therapy (WBRT) in patients with brain metastases from melanoma.

METHODS AND MATERIALS

Based on the intracranial disease burden, patients underwent WBRT (arm A) or SRS (arm B). The ipilimumab starting dose was 3 mg/kg every 3 weeks, starting on day 3 of WBRT or 2 days after SRS. The ipilimumab dose was escalated to 10 mg/kg using a 2-stage, 3+3 design. The primary endpoint was to determine the maximum tolerable dose of ipilimumab combined with radiation therapy. The secondary endpoints were overall survival, intracranial and extracranial control, progression-free survival, and toxicity. The ClinicalTrials.gov registration number is NCT01703507.

RESULTS

The characteristics of the 16 patients enrolled between 2011 and 2014 were mean age, 60 years; median number of brain metastases, 2 (range 1->10); and number with EC disease, 13 (81%). Treatment included WBRT (n=5), SRS (n=11), and ipilimumab 3 mg/kg (n=7) or 10 mg/kg (n=9). The median follow-up was 8 months (arm A) and 10.5 months (arm B). A total of 21 grade 1 to 2 neurotoxic effects occurred, with no dose-limiting toxicities. One patient experienced grade 3 neurotoxicity before ipilimumab administration. Ten additional grade 3 toxicities were reported, with gastrointestinal toxicities (n=5; 31%) the most common. No patient developed grade 4 or 5 toxicity. The median progression-free survival and overall survival in arm A was 2.5 months and 8 months and in arm B was 2.1 months and not reached, respectively.

CONCLUSIONS

Concurrent ipilimumab 10 mg/kg with SRS is safe. The WBRT arm was closed early because of slow accrual but demonstrated safety with ipilimumab 3 mg/kg. No patient experienced dose-limiting toxicity. Larger studies, including those with combination checkpoint inhibitor therapy and SRS, are warranted.

Evaluating the effect of therapy duration on survival in patients with metastatic castration-resistant prostate cancer receiving radium-223

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Background: The use of radium-223 in patients with metastatic castration-resistant prostate cancer (mCRPC) improves overall survival (OS) and quality of life. Combination of radium-223 with second-generation anti-androgens has further improved OS; however, the optimal length of radium-223 treatment for maximal effect remains unknown. Methods: We reviewed 35 consecutive patients with mCRPC who received radium-223 from December 2012 to August 2015 at Thomas Jefferson University. Patients were divided into two groups: those who received full treatment of 6 injections (n = 18) versus those who received less than 6 injections (n = 17). Kaplan-Meier analysis of OS were tested for difference by treatment group using Log Rank test. Univariable association with survival outcomes was calculated with univariable Cox regression and Log Rank tests. Results: Mean age was 73 ± 10 years and Karnofsky performance status (KPS) ranged from 50-90 (median, 80). Median follow-up was 13.9 months. Eighteen patients were receiving concurrent second generation anti-androgens at the start of treatment. Median OS was 12 months for patients who received 6 injections and 6.48 months for patients who received less than 6 injections (p = 0.0045). The results of univariate Cox regression analysis revealed full treatment was associated with increased OS (p = 0.0013). On multivariate analysis accounting for KPS, full treatment was significantly associated with improved OS (p = 0.0028). Conclusions: In this retrospective, single-institution analysis, we demonstrated that full course completion of radium-223 was associated with improved OS in patients with mCRPC. These patients should be optimally supported during treatment to allow for therapy completion.

Capturing the patient voice in radiotherapy trials: An analysis of trends and future directions of patient-reported outcomes

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Background: The importance of patient-reported outcomes (PROs) has been recognized and this data is increasingly being incorporated into modern radiotherapy (RT) trial design. Despite this, there is a lack of published data regarding collection and reporting of PRO data in the RT setting. We sought to systematically evaluate RT protocols to assess trends of PRO data collection and factors associated with reporting. Methods: We queried multi-institutional RT trials indexed on ClinicalTrials.gov, the Cochrane database, and MEDLINE and identified trials with full protocols available. We collected information in regards to study population, primary and secondary endpoints, quality of life measures, and PRO data. Descriptive and chi-squared analyses were employed to investigate trends and factors associated with PRO reporting. Results: 232 protocols were evaluable (1971-2014) from multiple cooperative groups. Of these, 198 were completed and 34 were in progress. Overall, only 41% of trials had protocol-specified collection of PROs. Of the 155 trials that had at least 1 published report, only 34 (22%) reported PRO data. All nine trials with PRO as a primary endpoint (9/9) had published reports with this information. Treatment era was associated with PRO collection, with 30% of trials collecting PRO data prior to 2005, 48% between 2006 and 2010, and 66% between 2011 and 2015 ( X2 [4, N = 232] = 15.79, p = 0.003). PROs were most likely to be collected in phase III trials ( X2 [4, N = 226] = 59.6, p < 0.0001). Conclusions: PROs are historically under collected and reported in cooperative group RT trials. Despite increasing PRO collection in modern trials, reporting remains suboptimal and may inaccurately inform survivorship issues. As digital literacy progresses, electronic PRO data may offer a potential avenue for improvement. Ultimately, PRO data will serve as a vital component to help define value in newly proposed payment models focused on improving quality of care while reducing cost of care.

Radioisotopes in management of metastatic prostate cancer

INTRODUCTION

Metastatic prostate cancer continues to be a leading cause of morbidity and mortality in men with prostate cancer. Over the last decade, the treatment landscape for patients with castrate-resistant disease has drastically changed, with several novel agents demonstrating an improvement in overall survival in large, multi-institutional randomized trials. Traditional treatment with radioisotopes has largely been in the palliative setting. However, the first in class radiopharmaceutical radium-223 has emerged as the only bone-directed treatment option demonstrating an improvement in overall survival.

METHODS

Medline publications from 1990 to 2016 were searched and reviewed to assess the use of currently approved radioisotopes in the management of prostate cancer including emerging data regarding integration with novel systemic therapies. New positron emission tomography-based radiotracers for advanced molecular imaging of prostate cancer were also queried.

RESULTS

Radioisotopes play a crucial role in the diagnosis and treatment of prostate cancer in the definitive and metastatic setting. Molecular imaging of prostate cancer and theranostics are currently being investigated in the clinical arena.

CONCLUSIONS

The use of modern radioisotopes in selected patients with mCRPC is associated with improvements in overall survival, pain control, and quality of life.

Brain Metastases in Patients with Gynecologic Cancers: A Single Institution Experience and Review of the Literature

Objective:

Brain Metastasis (BM) from primary gynecologic cancers is a rare entity. The advances and successes in the treatment of primary gynecologic malignancies, have led to prolonged survival and, a higher incidence of BM. This study aims to report the experience at our institution in managing these patients, and provide possible data points that may be essential to note as prognostic factors, and see if our findings are consistent with the literature in this subject. We also aim to provide a brief literature review of patients with gynecologic cancers and BM.

Methods:

This is a small single institution retrospective study of 23 patients with a gynecologic malignancy and BM, identified between the years 2007–2015. Data were collected on variables including patient demographics, disease and treatment.

Results:

The median overall survival from the primary diagnosis was 28 months. Median time from diagnosis of BM to death was 9 months.

Conclusion:

The outcomes in our study are similar to what is stated in the current literature with regard to BM from gynecologic malignancies. Our literature search also revealed that the molecular analysis and treatment of the primary tumor remain important to prevent BMs. The tendency of tumors to metastasize varies for one tumor type to another for the same type of tumor. The tendency to develop BM may not only depend on risk factors such as stage, grade, and histology, but also on the genetic profile of the primary tumor. The study suggests that multimodal treatment of BM has better outcomes in managing BM from gynecologic cancers.

Hepatoid Carcinoma of the Pancreas: A Case Report and Review of the Literature

Background: Hepatoid carcinoma (HC) is a rare extrahepatic malignancy that shares many morphological and serological features with hepatocellular carcinoma. HC has been reported to arise from several organs that are derived from the foregut endoderm, including the stomach, gallbladder, and pancreas. We present a case of an elderly man with hepatoid adenocarcinoma of the pancreatic head with duodenal invasion, presenting with pancreatitis and a gastrointestinal bleed. With only 23 reported cases at the time of our literature search, we discuss the presentation, histopathology, and management of such a rare disease.

Case presentation: A 71-year-old man presented initially with abdominal pain and was treated conservatively for pancreatitis. Four months later, he presented with melena and anemia. His examination was noncontributory. Esophagogastroduodenoscopy revealed a friable ampulla of Vater, and a CT scan of the abdomen showed a 4.5 cm pancreatic head mass. Fine needle aspirate revealed an epithelioid neoplasm with hepatoid morphology. Serum α-fetoprotein was normal. Surgical resection confirmed hepatoid adenocarcinoma of the pancreas with positive lymphadenopathy and negative margins. There was no radiographical or gross evidence of distant spread. Observation and adjuvant gemcitabine were discussed as possible options. The patient elected to receive care closer to home and will continue surveillance imaging.

Conclusion: With only 23 reported cases, pancreatic HC represents a rare entity within gastrointestinal oncology. There is no clear postoperative adjuvant standard therapy for this likely heterogeneous group of tumors. Although surgical resection is the mainstay of upfront treatment, metastatic disease to the lymph nodes or liver portends a poor prognosis and may warrant treatment such as transarterial embolization, chemotherapy, or radiotherapy.

Novel use of topical dapsone 5% gel for erythema elevatum diutinum: safer and effective

We present a case of an otherwise healthy 81-year-old gentleman with multiple asymptomatic, erythematous, indurated papules and plaques, ranging in size from 0.5 to 1.5 cm, involving the dorsal, lateral, and palmar surfaces of the fingers bilaterally. A clinical suspicion of erythema elevatum diutinum (EED) led to initial treatment with topical dapsone 5% gel (ACZONE; Allergan Inc, Irvine, CA). Lesional biopsy demonstrated a dense perivascular infiltration of polymorphonuclear leukocytes and chronic inflammatory cells with perivascular fibrin deposition. Focal neutrophilic infiltration of superficial dermal blood vessel walls was present, suggesting a leukocytoclastic vasculitis. Stains for bacteria and fungi were negative. Clinicopathologic findings were consistent with EED, and in the interim, improvement with topical dapsone 5% gel was noted. Addition of oral dapsone led to complete resolution of the lesions. We present this case to illustrate the subtle, indolent clinical presentation of EED and demonstrate the uncomplicated use of topical dapsone 5% gel for rapid improvement and subsequent successful treatment of localized disease.

Locking the ATP-operated clamp of DNA gyrase: probing the mechanism of strand passage

DNA gyrase catalyses DNA supercoiling by passing one segment of DNA (the T segment) through another (the G segment) in a reaction coupled to the binding and hydrolysis of ATP. The N-terminal domains of the gyrase B dimer constitute an ATP-operated clamp that is proposed to capture the T segment during the DNA supercoiling reaction. We have locked this clamp in the closed conformation using the non-hydrolysable ATP analogue ADPNP (5'-adenylyl beta,gamma-imidodiphosphate). The clamp-locked enzyme is able to bind and cleave DNA, albeit at a reduced level. Although the locked enzyme is not capable of carrying out DNA supercoiling, it can catalyse limited DNA relaxation, consistent with the ability to complete one strand passage event per enzyme molecule via entry of the T segment through the exit gate of the enzyme. The DNA-protein complex of the clamp-locked enzyme has a conformation that differs from the normal positively wrapped conformation of the gyrase-DNA complex. These experiments confirm the role of the ATP-operated clamp in the strand-passage reactions of gyrase and suggest a model for the interaction of DNA with gyrase in which a conformation with the T segment in equilibrium across the DNA gate can be achieved via T-segment entry through the ATP-operated clamp or through the exit gate.

The looming maladaptive style: anxiety, danger, and schematic processing

The importance of cognitive styles as psychological antecedents of psychopathology has gained increasing acceptance over the past 2 decades. Although ample research has explored cognitive styles that confer vulnerability to depression, cognitive styles that confer vulnerability to anxiety have received considerably less attention. In the present investigation, we examined the looming maladaptive style (LMS) as a cognitive style that functions as a danger schema to produce specific vulnerability to anxiety, but not to depression. In 4 studies, we examined the psychometric properties of a revised measure of the LMS, its predictive utility, and its effects on threat-related schematic processing. Results provided evidence for the validity of the LMS and indicated that it predicts anxiety and schematic processing of threat over and above the effects of other cognitive appraisals of threat, even in individuals who are currently nonanxious.

The looming maladaptive style: anxiety, danger, and schematic processing

The importance of cognitive styles as psychological antecedents of psychopathology has gained increasing acceptance over the past 2 decades. Although ample research has explored cognitive styles that confer vulnerability to depression, cognitive styles that confer vulnerability to anxiety have received considerably less attention. In the present investigation, we examined the looming maladaptive style (LMS) as a cognitive style that functions as a danger schema to produce specific vulnerability to anxiety, but not to depression. In 4 studies, we examined the psychometric properties of a revised measure of the LMS, its predictive utility, and its effects on threat-related schematic processing. Results provided evidence for the validity of the LMS and indicated that it predicts anxiety and schematic processing of threat over and above the effects of other cognitive appraisals of threat, even in individuals who are currently nonanxious.

Temperature-sensitive suppressor mutations of the Escherichia coli DNA gyrase B protein

Escherichia coli strain LE316 contains a mutation in gyrB that results in the substitution of Val164 to Gly and confers both chlorobiocin resistance and temperature sensitivity. Selection for suppressors of the ts phenotype yielded second-site mutations in GyrB at His38 and Thr157. The properties of proteins bearing these mutations have been characterized, and a mechanism of suppression is proposed based upon structural considerations.

Locking the DNA gate of DNA gyrase: investigating the effects on DNA cleavage and ATP hydrolysis

Supercoiling by DNA gyrase involves the passage of one segment of double-stranded DNA through another. This requires a DNA duplex to be cleaved and the broken ends separated by at least 20 A. This is accomplished by the opening of a dimer interface, termed the DNA gate, which is covalently attached to the broken ends of the DNA. After strand passage, the DNA gate closes allowing the reunion of the broken ends. We have cross-linked the DNA gate of gyrase using cysteine cross-linking to block gate opening. We show that this locked gate mutant can bind quinolone drugs and perform DNA cleavage. However, locking the DNA gate prevents strand passage and the ability of DNA to stimulate ATP hydrolysis. We discuss the mechanistic implications of these results.

Probing the two-gate mechanism of DNA gyrase using cysteine cross-linking

Cross-linking a pair of novel cysteine residues on either side of the bottom dimer interface of DNA gyrase blocks catalytic supercoiling. Limited strand passage is allowed, but release of the transported DNA segment (T segment) via opening of the bottom dimer interface is prevented. In contrast, ATP-independent relaxation of negatively supercoiled DNA is completely abolished, suggesting that T-segment entry via the bottom gate is blocked. These findings support a two-gate model for supercoiling by DNA gyrase and suggest that relaxation by gyrase is the reverse of supercoiling. Cross-linking a truncated version of gyrase (A64(2)B2), which lacks the DNA wrapping domains, does not block ATP-dependent relaxation. This indicates that passage of DNA through the bottom dimer interface is not essential for this reaction. The mechanistic implications of these results are discussed.

Treatment of stress urinary incontinence due to paravaginal fascial defect

This study supports the thesis that the physical findings of pelvic relaxation, such as cystourethrocele, are the results of isolated defects in the pelvic fascia rather than the results of generalized stretching or attenuation of the supporting structures. The most frequently encountered defect resulting in cystourethrocele with stress urinary incontinence was a paravaginal break in the pubocervical segment of the endopelvic fascia between the lateral edge of the vagina and the pelvic sidewall. The operative approach to this paravaginal defect is described. The overall results in 233 procedures performed by 2 separate groups are analyzed. Functionally satisfactory results were obtained in over 95% of patients with 2 to 8 years of follow-up. The use of an indwelling urethral catheter was found to be unnecessary, and all patients experienced a rapid return of normal bladder function. The average length of the postoperative hospital stay was 5 days.

A new look at pelvic relaxation

The concept is presented that most cystoceles and/or urethroceles result from insolated defects in the connective tissue supports of the anterior quadrant of the pelvis. Four areas in which defects have been found to occur are identified. Sixty patients are presented who were found to have isolated defects in the endopelvic fascia at the lateral sidewall of the pelvis with significant cystourethroceles and stress urinary incontinence. The surgical treatment consisted only of a direct approach to and closure of the isolated defect. The operative results at 3 to 48 months were excellent in 91.7 per cent, improved in 5 per cent, and failed in 3.3 per cent. Discussion is offered of the possibility of the study of the pelvic floor from the viewpoint of a mechanical engineer.

Decreasing postpartum sexual abstinence time

Postpartum sexual abstinence time can be safely shortened for most patients when episiotomy repair is done meticulously with fine PGA suture on small needles. The time preferred by patients for resumption of intercourse seems to be between the second and third postpartum week. We have seen no ill effects from this, and we feel that sexual intercourse at these early dates does not influence the healing of the episiotomy in any way.

The moon and mental illness: a failure to confirm the Transylvania effect

The Transylvania effect—the notion that certain patient behavior coincides with moon phases—was carefully tested during a 3-mo. summer period in 1969. Three non-reactive measures were employed and no significant results were found on any of them. It was concluded that a meaningful correlation between the moon phase and acting out behavior of mental patients did not exist and, therefore, did nor explain many unresolved problems in the area.