Improving Patient Compliance with Vaginal Dilator Therapy by Implementation of Sexual Health Consult in Gynecologic Malignancies after Radiation Therapy

PURPOSE/OBJECTIVE(S)

Typical vaginal dilator therapy (VDT) compliance falls short at approximately 30% of patients in reported studies, which could lead to vaginal stenosis (VS) in as high as 88% of patients who undergo radiation therapy (RT) for gynecologic malignancies. In an ongoing effort to improve adherence to VDT aimed to prevent vaginal stenosis post pelvic and vaginal RT, a prospective study was implemented to assess the feasibility and the impact on vaginal dilator therapy adherence when implementing a consult with the oncology women's sexual health clinic following the completion of radiation therapy.

MATERIALS/METHODS

This was a single institution, prospective analysis and feasibility study that included patients diagnosed with a gynecologic cancer who were treated with RT to the pelvic and or vaginal tissues. Using purposive sampling, the treating radiation oncologists identified eligible patients and referred them to the oncology women's sexual health clinic for consult four to six weeks status post completion of RT in a six-month period. A post treatment survey was conducted via a telephone interview 12 weeks after the sexual health clinic initial consult to assess vaginal dilator therapy compliance. Descriptive statistics were calculated.

RESULTS

Pre-intervention retrospective data analysis revealed poor compliance to VDT with only 3 of 40 (7.5%) patients judged as compliant. Post-intervention, 30 of 37 (81.1%) patients in the sample were judged compliant. The adherence rate in the post-intervention group was significantly higher (Fisher's Exact Test two-tailed p-value < 0.0001). With confidence of 95%, the proportion of the potential population that would adhere post intervention was between 68.5% and 93.7%. Sociodemographic and clinical characteristics did not have a statistically significant correlation with VDT compliance.

CONCLUSION

Implementing a referral to an oncology women's sexual health clinic at the completion of RT for the sample population is feasible. Our project demonstrates that instituting this new sexual health clinic may have a large, positive impact on patient compliance to vaginal dilator therapy. More importantly, this may lead to decrease incidences of vaginal stenosis and improvement in patient health outcomes and quality of life (QoL).

Impact of SARS-CoV-2 Pandemic and Strategies for Resumption of Activities During the Second Wave of the Pandemic: A Report From Eight Paediatric Hospitals From the ECHO Network

The Severe Acute Respiratory Syndrome CoronaVirus type 2 (SARS-CoV-2) pandemic impacted the organization of paediatric hospitals. This study aimed to evaluate the preparedness for the pandemic among a European network of children's hospitals and to explore the strategies to restart health care services. A cross-sectional, web-based survey was distributed in May 2020 to the 13 children's tertiary care hospitals belonging to the European Children's Hospitals Organisation. Responses were obtained from eight hospitals (62%). Significant reductions were observed in accesses to the emergency departments (41.7%), outpatient visits (35.7%), intensive and non-intensive care unit inpatient admissions (16.4 and 13%, respectively) between February 1 and April 30, 2020 as compared with the same period of 2019. Overall, 93 children with SARS CoV-2 infection were admitted to inpatient wards. All the hospitals created SARS-CoV-2 preparedness plans for the diagnosis and management of infected patients. Routine activities were re-scheduled. Four hospitals shared their own staff with adult units, two designated bed spaces for adults and only one admitted adults to inpatient wards. The three main components for the resumption of clinical activities were testing, source control, and reorganization of spaces and flows. Telemedicine and telehealth services were used before the SARS-CoV-2 pandemic by three hospitals and by all the hospitals during it.

Conclusion: The present study provides a perspective on preparedness to SARS-CoV-2 pandemic among eight large European children's hospitals, on the impact of the pandemic on the hospital activities and on the strategies adopted to restart clinical activities.

The cross-sectional association between diabetes and orthostatic hypotension in community-dwelling older people

AIMS

Orthostatic hypotension is a recognized complication of diabetes, but studies examining prevalence in diabetes are limited. The aim of this study was to ascertain the prevalence of orthostatic hypotension and the pattern of orthostatic BP response in a cohort of people with diabetes aged ≥ 50 years, embedded within the Irish Longitudinal Study of Ageing.

METHODS

Orthostatic hypotension was defined as a drop in systolic blood pressure (SBP) ≥ 20 mmHg or drop in diastolic blood pressure (DBP) ≥ 10 mmHg at 30 s after standing. Diabetes was defined by self-report but cross-checked against HbA_1c and medication records. Multilevel mixed effects linear regression models were used to compare orthostatic BP in people with and without diabetes.

RESULTS

Some 3222 people were included, 7% (213 of 3222) of whom had diabetes. Prevalence of orthostatic hypotension in the group with diabetes was 22% (46 of 213) vs. 13% in those without diabetes; χ² = 12.43; P < 0.001. Multilevel models demonstrated prolonged recovery of DBP in people with diabetes, with only 41% (87 of 213) returning to baseline by 60 s. Logistic regression models demonstrated that diabetes was associated with a significantly increased likelihood of orthostatic hypotension (odds ratio 1.84, 95% confidence interval 1.30-2.59; P = 0.001) and this remained robust after controlling for covariates.

CONCLUSION

Over one-fifth of older people with diabetes had orthostatic hypotension. Recovery of DBP is related to dynamic changes in total peripheral resistance and impairment of this baroreflex-mediated response may explain the higher prevalence in diabetes. Given the prognostic implications when co-existing with diabetes, orthostatic hypotension may represent a potentially modifiable risk factor for adverse outcomes in late-life diabetes.

Measuring the impact of oesophagectomy on physical functioning and physical activity participation: a prospective study

BACKGROUND

Oesophagectomy remains the only curative intervention for oesophageal cancer, with defined nutritional and health-related quality of life (HR-QOL) consequences. It follows therefore that there is a significant risk of decline in physical wellbeing with oesophagectomy however this has been inadequately quantified. This study prospectively examines change in physical functioning and habitual physical activity participation, from pre-surgery through 6-months post-oesophagectomy.

METHODS

Patients scheduled for oesophagectomy with curative intent were recruited. Key domains of physical functioning including exercise tolerance (six-minute walk test (6MWT)) and muscle strength (hand-grip strength), and habitual physical activity participation, including sedentary behaviour (accelerometry) were measured pre-surgery (T0) and repeated at 1-month (T1) and 6-months (T2) post-surgery. HR-QOL was measured using the EORTC-QOL C30.

RESULTS

Thirty-six participants were studied (mean age 62.4 (8.8) years, n = 26 male, n = 26 transthoracic oesophagectomy). Mean 6MWT distance decreased significantly from T0 to T1 (p = 0.006) and returned to T0 levels between T1 and T2 (p < 0.001). Percentage time spent sedentary increased throughout recovery (p < 0.001) and remained significantly higher at T2 in comparison to T0 (p = 0.003). In contrast, percentage time spent engaged in either light or moderate-to-vigorous intensity activity, all reduced significantly (p < 0.001 for both) and remained significantly lower at T2 in comparison to T0 (p = 0.009 and p = 0.01 respectively). Patients reported deficits in multiple domains of HR-QOL during recovery including global health status (p = 0.04), physical functioning (p < 0.001) and role functioning (p < 0.001). Role functioning remained a clinically important 33-points lower than pre-operative values at T2.

CONCLUSION

Habitual physical activity participation remains significantly impaired at 6-months post-oesophagectomy. Physical activity is a measurable and modifiable target for physical rehabilitation, which is closely aligned with patient-reported deficits in role functioning. Rehabilitation aimed at optimising physical health in oesophageal cancer survivorship is warranted.

Effect of preoperative inspiratory muscle training on physical functioning following esophagectomy

This study aims to examine the effect of preoperative inspiratory muscle training (IMT) on pre- and postoperative functional exercise performance in patients undergoing esophagectomy. A subcohort of patients recruited to the PREPARE randomized control trial were studied. Following evaluation of respiratory muscle function (spirometry, maximum inspiratory pressure (MIP), and inspiratory muscle endurance), postoperative mobilization (accelerometry) and postoperative physical functioning (6-minute walk test (6MWT)), participants scheduled for esophagectomy were randomly assigned to either 2 weeks of preoperative IMT or a control group. Measures were repeated on the day before surgery and postoperatively. Sixty participants (mean (standard deviation) age 64.13 (7.8) years; n = 42 male; n = 43 transthoracic esophagectomy; n = 17 transhiatial esophagectomy) were included in the final analysis (n = 28 IMT; n = 32 control). There was a significant improvement in preoperative MIP (P = 0.03) and inspiratory muscle endurance (P = 0.04); however preoperative 6MWT distance did not change. Postoperatively, control participants were more active on postoperative day (POD)1, and from POD1-POD5 (P = 0.04). Predischarge, 6MWT distance was significantly lower in the IMT group (305.61 (116.3) m) compared to controls (380.2 (47.1) m, P = 0.03). Despite an increase in preoperative respiratory muscle function, preoperative IMT does not improve pre- or postoperative physical functioning or postoperative mobilization following esophagectomy.

Aβ oligomer toxicity inhibitor protects memory in models of synaptic toxicity

BACKGROUND AND PURPOSE

Amyloid-β (Aβ) aggregation into synaptotoxic, prefibrillar oligomers is a major pathogenic event underlying the neuropathology of Alzheimer's disease (AD). The pharmacological and neuroprotective properties of a novel Aβ aggregation inhibitor, SEN1269, were investigated on aggregation and cell viability and in test systems relevant to synaptic function and memory, using both synthetic Aβ(1-42) and cell-derived Aβ oligomers.

EXPERIMENTAL APPROACH

Surface plasmon resonance studies measured binding of SEN1269 to Aβ(1-42) . Thioflavin-T fluorescence and MTT assays were used to measure its ability to block Aβ(1-42) -induced aggregation and reduction in cell viability. In vitro and in vivo long-term potentiation (LTP) experiments measured the effect of SEN1269 on deficits induced by synthetic Aβ(1-42) and cell-derived Aβ oligomers. Following i.c.v. administration of the latter, a complex (alternating-lever cyclic ratio) schedule of operant responding measured effects on memory in freely moving rats.

KEY RESULTS

SEN1269 demonstrated direct binding to monomeric Aβ(1-42) , produced a concentration-related blockade of Aβ(1-42) aggregation and protected neuronal cell lines exposed to Aβ(1-42) . In vitro, SEN1269 alleviated deficits in hippocampal LTP induced by Aβ(1-42) and cell-derived Aβ oligomers. In vivo, SEN1269 reduced the deficits in LTP and memory induced by i.c.v. administration of cell-derived Aβ oligomers.

CONCLUSIONS AND IMPLICATIONS

SEN1269 protected cells exposed to Aβ(1-42) , displayed central activity with respect to reducing Aβ-induced neurotoxicity and was neuroprotective in electrophysiological and behavioural models of memory relevant to Aβ-induced neurodegeneration. It represents a promising lead for designing inhibitors of Aβ-mediated synaptic toxicity as potential neuroprotective agents for treating AD.

Detection of a possible case of pulmonary tumour thromboembolism by endobronchial ultrasound

-

Intracellular acidification delays hormonal G2/M transition and inhibits G2/M transition triggered by thiophosphorylated MAPK in Xenopus oocytes

Xenopus oocyte maturation is analogous to G2/M transition and characterized by germinal vesicle breakdown (GVBD), spindle formation, activation of MPF and Mos-Xp42(Mpk1) pathways. It is accompanied prior to GVBD by a transient increase in intracellular pH. We determined that a well known acidifying compound, NH(4)Cl, delayed progesterone-induced GVBD in a dose-dependent manner. GVBD(50) was delayed up to 2.3-fold by 10 mM NH(4)Cl. Cyclin B2 phosphorylation, Cdk1 Tyr15 dephosphorylation as well as p39(Mos) accumulation, Xp42(Mpk1) and p90(Rsk) phosphorylation induced by progesterone were also delayed by incubation of oocyte in NH(4)Cl. The delay induced by NH(4)Cl was prevented by injection of MOPS buffer pH 7.7. In contrast to acidifying medium, alkalyzing treatment such as Tris buffer pH 9 injections, accelerated GVBD, MPF and Xp42(Mpk1) activation, indicating that pHi changes control early steps of G2/M dynamics. When injected in an immature recipient oocyte, egg cytoplasm triggers GVBD through MPF auto-amplification, independently of protein synthesis. In these conditions, GVBD and Xp42(Mpk1) activation were delayed by high concentration of NH(4)Cl, which never prevented or delayed MPF activation. Strickingly, NH(4)Cl strongly inhibited thiophosphorylated active MAPK-induced GVBD and MPF activation. Nevertheless, Tris pH 9 did not have any effects on egg cytoplasm- or active MAPK-induced GVBD. Taken together, our results suggest that dynamic of early events driving Xp42(Mpk1) and MPF activation induced by progesterone may be negatively or positively regulated by pH(i) changes. However Xp42(Mpk1) pathway was inhibited by acidification alone. Finally, MPF auto-amplification loop was not sensitive to pH(i) changes.

Transgenic overexpression of locally acting insulin-like growth factor-1 inhibits ubiquitin-mediated muscle atrophy in chronic left-ventricular dysfunction

Metabolic abnormalities develop in various chronic diseases and lead to progressive catabolism with decrements in the skeletal musculature that result in muscle atrophy. We investigated pathways of skeletal muscle proteolysis using an experimental model of chronic left-ventricular dysfunction. Skeletal muscle atrophy developed in wild-type mice 12 weeks following myocardial infarction accompanied by an increase in total protein ubiquitination and enhanced proteasome activity, activation of Foxo transcription factors, and robust induction of the ubiquitin-protein ligase atrogin-1/MAFbx. Further studies identified skeletal muscle myosin as a specific target of ubiquitin-mediated degradation in muscle atrophy. In contrast, transgenic overexpression of a local isoform of insulin-like growth factor-1 prevented muscle atrophy and increased proteasome activity, inhibited skeletal muscle activation primarily of Foxo4, and blocked the expression of atrogin-1/MAFbx. These results suggest that skeletal muscle atrophy occurs through increased activity of the ubiquitin-proteasome pathway. The inhibition of muscle atrophy by local insulin-like growth factor-1 provides a promising therapeutic avenue for the prevention of skeletal muscle wasting in chronic heart failure and potentially other chronic diseases associated with skeletal muscle atrophy.

Characterization of adriamycin-induced G2 arrest and its abrogation by caffeine in FL-amnion cells with or without p53

We investigated the effect of Adriamycin on FL-amnion (FL) cells. After treatment with the drug, the cells arrested at G2, but we did not detect an increase in the p21 levels. We established a p53-deficient derivative of these cells, in which G2 arrest also occurred after treatment with Adriamycin, suggesting that the arrest we observed in these cells is independent of the p53 pathway. Low doses of Adriamycin (100-200 ng/ml) induced G2 arrest, while late S-phase arrest was observed at high doses (500-1000 ng/ml) in both FL and p53-deficient FL cells. Accumulation of cyclin B1 was detected only in cells arrested at G2, and not in those arrested at S phase, suggesting that the S-phase checkpoint functioned efficiently even in p53-deficient FL cells. In both cell lines, caffeine-induced activation of CDC2 kinase was detected only in cells arrested at G2 and CDC2 kinase-activated cells died exhibiting features of apoptosis. CDC2 kinase activation was inhibited by cycloheximide. Furthermore, cycloheximide inhibited activation of CDK2:cyclin A, which normally precedes CDC2 kinase activation in caffeine-treated cells. These results suggest that p53 and p21 do not have special roles in the S- and G2-phase checkpoints and that CDK2:cyclin A could be the target of the G2-phase DNA damage checkpoint.

Colonic motor function in humans is not affected by gender

Functional abdominal pain, including the irritable bowel syndrome, is more common in females. Our aim was to determine if differences in motility or biomechanical properties of the colon could account for this gender difference. In 18 healthy subjects (nine males), a catheter assembly incorporating a balloon and perfused side holes, connected to a barostat, was positioned in the left colon. The system was used to determine compliance, sensation in response to phasic balloon distension, and changes in motor activity and tone in response to a meal. There was no significant difference in any of these variables between males and females. We conclude that there is no gender difference in colonic motor function or sensation to balloon distension. The increased prevalence of irritable bowel syndrome in females may be related to psychosocial factors rather than differences in colonic motor function.

L-Carnitine supplementation combined with aerobic training does not promote weight loss in moderately obese women

L-Carnitine (L-C) transports fatty acids into mitochondria for oxidation and is marketed as a weight loss supplement. In a double-blind investigation to test the weight loss efficacy of L-C, 36 moderately overweight premenopausal women were pair matched on Body Mass Index (BMI) and randomly assigned to two groups (N = 18). For 8 weeks the L-C group ingested 2 g twice daily of L-C, while the placebo (P) group ingested the same amount of lactose. All subjects walked for 30 min (60-70% maximum heart rate) 4 days/week. Body composition, resting energy expenditure (REE) and substrate utilization were estimated before and after treatment. For the subjects who completed the study (15 P, 13 L-C), no significant changes in mean total body mass (TBM), fat mass FM, and resting lipid utilization occurred over time, nor were there any significant differences between groups for any variable. Conversely REE increased significantly for all subjects, but no between group differences existed. Five of the L-C group experienced nausea or diarrhea and consequently did not complete the study. Eight weeks of L-C ingestion and walking did not significantly alter the TBM or FM of overweight women, thereby casting doubt on the efficacy of L-C supplementation for weight loss.

Activation of Xenopus eggs by the kinase inhibitor 6-DMAP suggests a differential regulation of cyclin B and p39(mos) proteolysis

In Xenopus eggs, metaphase II arrest is due to the cytostatic factor that maintains a high level of MPF activity. Kinases are important in this phenomenon since p39(mos) and MAPK play a part in the cytostatic activity whereas p34(cdc2) is the catalytic subunit of MPF. Fertilization induces a rise in intracellular calcium leading to egg activation that can be mimicked by calcium-increasing agents such as calcium ionophore. We have performed on Xenopus eggs a biochemical comparison of the effects of the kinase inhibitor 6-DMAP and the calcium ionophore. Both drugs were able to induce pronucleus formation but the underlying molecular events were different. The inactivation of MAPK occurred earlier in eggs exposed to 6-DMAP. Cyclins B1 and B2 were stable and p39(mos) was proteolysed in 6-DMAP-treated eggs while the three proteins underwent degradation in A23187-treated ones. These results suggest a differential regulation of ubiquitin-dependent proteolysis of cyclin B and p39(mos).

Inhibition of protein tyrosine phosphatases blocks calcium-induced activation of metaphase II-arrested oocytes of Xenopus laevis

We have studied the effect of a protein tyrosine phosphatases (PTP) inhibitor on calcium-induced activation of Xenopus laevis oocytes arrested at metaphase II. Ammonium molybdate microinjection blocked pronucleus formation following A23187 treatment while cortical granules still underwent exocytosis. Pronuclei still occurred in ammonium molybdate-injected oocytes following 6-DMAP addition. Changes that usually occurred following A23187 exposure were inhibited in the presence of ammonium molybdate in the oocyte: MAPK dephosphorylation, p34(cdc2) rephosphorylation and cyclin B2 and p39(mos) proteolysis. These results suggest that a PTP is involved in the activation of the ubiquitin-dependent degradation machinery.

The role of the destruction box and its neighbouring lysine residues in cyclin B for anaphase ubiquitin-dependent proteolysis in fission yeast: defining the D-box receptor

Programmed proteolysis of proteins such as mitotic cyclins and Cut2/Pds1p requires a 9-residue conserved motif known as the destruction box (D-box). Strong expression of protein fragments containing destruction boxes, such as the first 70 residues of Cdc13 (N70), inhibits the growth of Schizosaccharomyces pombe at metaphase. This inhibition can be overcome either by removal of all lysine residues from N70 using site-directed mutagenesis (K0-N70) or by raising the concentration of intracellular ubiquitin. Consistent with the idea that competition for ubiquitin accounts for some of its inhibitory effects, wild-type N70 not only stabilized D-box proteins, but also Rum1 and Cdc18, which are degraded by a different pathway. The K0-N70 construct was neither polyubiquitinated nor degraded in vitro, but it blocked the growth of strains of yeast in which anaphase-promoting complex/cyclosome (APC/C) function was compromised by mutation, and specifically inhibited proteolysis of APC/C substrates in vivo. Both K0-N70 and 20-residue D-box peptides blocked polyubiquitination of other D-box-containing substrates in a cell-free ubiquitination assay system. These data suggest the existence of a D-box receptor protein that recognizes D-boxes prior to ubiquitination.

Cyclin B2-null mice develop normally and are fertile whereas cyclin B1-null mice die in utero

Two B-type cyclins, B1 and B2, have been identified in mammals. Proliferating cells express both cyclins, which bind to and activate p34(cdc2). To test whether the two B-type cyclins have distinct roles, we generated lines of transgenic mice, one lacking cyclin B1 and the other lacking cyclin B2. Cyclin B1 proved to be an essential gene; no homozygous B1-null pups were born. In contrast, nullizygous B2 mice developed normally and did not display any obvious abnormalities. Both male and female cyclin B2-null mice were fertile, which was unexpected in view of the high levels and distinct patterns of expression of cyclin B2 during spermatogenesis. We show that the expression of cyclin B1 overlaps the expression of cyclin B2 in the mature testis, but not vice versa. Cyclin B1 can be found both on intracellular membranes and free in the cytoplasm, in contrast to cyclin B2, which is membrane-associated. These observations suggest that cyclin B1 may compensate for the loss of cyclin B2 in the mutant mice, and implies that cyclin B1 is capable of targeting the p34(cdc2) kinase to the essential substrates of cyclin B2.

Cell cycle regulatory proteins--an overview with relevance to oral cancer

The cell cycle is controlled by a number of highly conserved proteins, found in species as diverse as yeast and mammals. The study of these proteins is a rapidly advancing field that is increasing our understanding of normal and abnormal cell division. Disruption of the cell cycle has been demonstrated in several different types of neoplasm, and there is increasing evidence that, in head and neck tumours, there is aberrant control of cyclins, cell cycle protein kinases and their inhibitors. Because of the phase specificity of some of the control proteins, antibodies to them are proving to be of value in studying cell kinetics of both normal tissues and malignant tumours.

Procaine-induced maturation of Xenopus oocytes is mediated by a transient activation of M-phase promoting factor

We have recently shown that the incubation of Xenopus laevis oocytes in procaine-containing solutions induced germinal vesicle breakdown without white spot formation and, in some cases, with the appearance of spindle and chromosomes in the cytoplasm. The present study was performed to determine whether M-phase promoting factor was involved in this unusual maturation. Procaine failed to induce maturation in the presence of 6-dimethylamino purine or roscovitine, which are both known to inhibit p34cdc2 kinase. Histone H1 kinase activity was detected in procaine-treated oocytes but it was always lower than in progesterone-treated controls. A shift in p34cdc2 was observed in oocytes that had been exposed to procaine for 16 h, but it was not detected in those exposed for 24 h. Finally, cytoplasm transfer experiments demonstrated that the maturation promoting activity that occurred in oocytes incubated in procaine for 16 h could induce maturation of recipient stage VI oocytes. This transferable activity was weaker than that from progesterone-treated controls since only 30% of the recipients underwent germinal vesicle breakdown and only a few spindles were observed, which were not always correctly located. Taken together these results demonstrate that M-phase promoting factor is involved in the procaine maturing effect despite some differences compared with progesterone-treated oocytes which might explain the particular type of maturation induced by this substance. The discovery of the mechanisms by which procaine is able to activate M-phase promoting factor might now help in the understanding of some steps in progesterone-induced maturation that have still to be elucidated.

Functional interaction between DP-1 and p53

The cellular transcription factor DRTF1/E2F and the tumor suppressor protein p53 play important roles in controlling early cell cycle events. DRTF1/E2F is believed to coordinate and integrate the transcription of cell cycle-regulating genes, for example, those involved in DNA synthesis, with the activity of regulatory proteins, such as the retinoblastoma tumor suppressor gene product (pRb), which modulate its transcriptional activity. In contrast, p53 is thought to monitor the integrity of chromosomal DNA and when appropriate interfere with cell cycle progression, for example, in response to DNA damage. Generic DRTF1/E2F DNA binding activity and transcriptional activation arise when members of two distinct families of proteins, such as DP-1 and E2F-1, interact as DP/E2F heterodimers. In many cell types, DP-1 is a widespread component of DRTF1/E2F DNA binding activity which when expressed at high levels oncogenically transforms embryonic fibroblasts. Here, we document an association between DP-1 and p53 and demonstrate its presence in mammalian cell extracts. In vitro p53 interacts with an immunochemically distinct form of DP-1 and in vivo can regulate transcription driven by the DP-1/E2F-1 heterodimer. At the biochemical level, p53 competes with E2F-1 for DP-1, with a consequent reduction in DNA binding activity. Mutational analysis defines within DP-1 a C-terminal region required for the interaction with p53 and within p53 an N-terminal region distinct from that required to bind to MDM2. Our results establish DRTF1/E2F as a common cellular target in growth control mediated through the activities of pRb and p53 and suggest an alternative mechanism through which p53 may regulate cellular proliferation.

The role of proteolysis in cell cycle progression in Schizosaccharomyces pombe

A cell-free system derived from Xenopus eggs was used to identify the 'destruction box' of the Schizosaccharomyces pombe B-type cyclin, Cdc13, as residues 59-67: RHALDDVSN. Expression of indestructible Cdc13 from a regulated promoter in S.pombe blocked cells in anaphase and inhibited septation, showing that destruction of Cdc13 is necessary for exit from mitosis, but not for sister chromatid separation. In contrast, strong expression of a polypeptide comprising the N-terminal 70 residues of Cdc13, which acts as a competitive inhibitor of destruction box-mediated proteolysis, inhibited both sister chromatid separation and the destruction of Cdc13, whereas an equivalent construct with a mutated destruction box did not. Appropriately timed expression of this N-terminal fragment of Cdc13 overcame the G1 arrest seen in cdc10 mutant strains, suggesting that proteins required for the initiation of S phase are subject to destruction by the same proteolytic machinery as cyclin.

Student doctors and women in labor: attitudes and expectations

OBJECTIVE

To compare the attitudes and expectations that obstetric patients and medical students bring to the student-patient relationship in intrapartum care.

METHODS

Written questionnaires were distributed to obstetric patients who had students assist in their labor and delivery care and to medical students who had completed their clinical clerkship year. Responses of 222 patients and 67 students were analyzed for differences in expectations of student participation and assessment of skills.

RESULTS

Responses of medical students and patients were significantly different in all attitudes and expectations studied. One hundred thirty-six (61%) patients compared with 27 (40%) students identified the patients' wish to contribute to the education of students as the most important reason for agreeing to student participation. All patients felt that student participation should be requested rather than assigned, with 194 (87%) patients but only 30 (45%) students wishing to have the student absent from the room at the time of the request. Mean ratings of different student skills tended to be higher from patients (1.3-1.8 on a seven-point Likert scale) than from the students themselves (range 1.6-2.4). Although students' expectations of participation in patient care were high, patients indicated expectations of fairly low levels of student involvement in communication, examination, labor support, and procedures.

CONCLUSION

Students have high expectations for their active involvement in intrapartum care and tend to under-estimate the sense of altruism that motivates patients to allow student participation. Patients have low expectations of levels of student participation in their care, but are overall quite satisfied with the skills of the students. These differences highlight the need for the development of educational objectives that clarify student roles in clinical clerkships and the process of informed consent for student participation.

Isokinetic muscle performance in healthy female handball players and players with a unilateral anterior cruciate ligament reconstruction

A total of 114 healthy female European team handball players in the elite to second division with no previous ACL injury, and the uninjured legs of 22 females with a unilaterally reconstructed ACL (the injury sustained while playing handball; mean time from reconstruction 15 months) were examined with a Biodex isokinetic testing device. Five extensions and flexions at lower speed (60 degrees/s) and 15 repetitions at higher speed (240 degrees/s) were performed. Gravity-corrected peak torque values for flexion and extension were obtained, and hamstrings-to-quadriceps ratios (H/Q) were calculated at both speeds. Compared with the control group, the uninjured legs of the injury group showed 8% weaker quadriceps muscles and 14% higher H/Q ratios at higher speed. The other between-group comparisons were not significant. These differences could have been developed by strength reduction after the injury in the noninjured limb due-to-insufficient rehabilitation, by a weaker musculature in the patient group already initially, or by both mechanisms. If the second option is true, the finding may indicate that weak quadriceps musculature is one of the risk factors for anterior cruciate ligament injuries. The study establishes additional normative data on hamstrings and quadriceps torque on high-level female handball players.

The localization of p34cdc2 in the cells of normal, hyperplastic, and malignant epithelial and lymphoid tissues of the oral cavity

The expression of p34cdc2 has been examined in normal, hyperplastic, and malignant oral epithelia and lymphoid tissues. Four monoclonal antibodies were prepared against Xenopus p34cdc2, three of which react specifically with human p34cdc2 and not with p33cdk2. These produced similar patterns of staining in both fixed and frozen sections of human material. Staining occurred mainly in the proliferative compartments of normal and hyperplastic tissues. In normal oral epithelia, parabasal and basal cells were the most strongly stained, with lighter cytoplasmic staining in lower prickle cells. In tonsillar germinal centres, a high proportion of cells was stained, with fewer positive cells in interfollicular zones, a distribution in keeping with the known pattern of cell proliferation. In normal cells, the intracellular location of p34cdc2 was cytoplasmic until early prophase, but in oral squamous cell carcinomas and lymphomas, it was located in both cytoplasm and nucleus during interphase and a larger fraction of cells was positive than in the equivalent normal tissues. Higher-grade neoplasms showed both a higher intensity of staining and a higher proportion of p34cdc2-positive cells.

Expression and subcellular localization of CDK2 and cdc2 kinases and their common partner cyclin A in thyroid epithelial cells: comparison of cyclic AMP-dependent and -independent cell cycles

Dog thyroid epithelial cells in primary culture constitute a model of positive control of DNA synthesis initiation and G0-S prereplicative phase progression by cyclic AMP as a second messenger for TSH. In tis early steps, this mitogenic control is quite distinct from cyclic AMP-independent mitogenic cascades elicited by growth factors. We demonstrate here that TSH (cyclic AMP) and EGF+serum (cyclic AMP-independent) stimulations cooperate and finally converge on proteins that control the cell cycle machinery. This convergence included a common induction of the expression of cyclin A and p34cdc2, and to a lesser extent of p33/38cdk2, which was already expressed in quiescent thyroid cells, and common changes of cdc2 and CDK2 phosphorylations as evidenced by electrophoretic mobility shifts. Kinetic differences in these processes after stimulation by TSH or EGF+serum or by these factors in combination correlated with differences in cell cycle kinetics. Moreover, an immunofluorescence analysis of these proteins using the double labeling of PCNA as a marker of each cell cycle phase shows: (1) a previously undescribed nuclear translocation of CDK2 before S phase initiation; (2) a sudden increase of cdc2 nuclear immunoreactivity at G2/mitosis transition. These data support the roles of CDK2 and cdc2 at G1/S and G2/mitosis transitions, respectively. (3) We were unable to demonstrate in individual cells a strict association between the nuclear appearance of cyclin A and G1/S transition, and an association of cyclin A and CDK2 with PCNA-stained DNA replication sites. On the other hand, the lengthening of G2 phase in the TSH/cyclic AMP-dependent thyroid cell cycle was associated with a stabilization of Tyr15 inhibitory phosphorylation of cdc2 and an especially high nuclear concentration of cyclin A and CDK2. We hypothesize that high nuclear accumulation of cyclin A and CDK2 during G2 phase could be causative in the cyclic AMP-dependent delay of mitosis onset.

The effect of epidural blockade on gastric intramucosal pH in the peri-operative period

Patients undergoing major surgery are at risk of developing gut ischaemia and multiple organ failure. The gastric tonometer provides a relatively non-invasive method of assessing the adequacy of gut blood flow. Patients who develop repeated episodes of splanchnic ischaemia in the postoperative period, as evidenced by a low gastric intramucosal pH, have a higher mortality than those who do not. This randomised, controlled study was conducted to assess the effect of epidural blockade with bupivacaine on gastric intramucosal pH measurements in patients undergoing major surgery. A significantly lower proportion of patients with epidural blockade developed gastric intramucosal pH values < 7.32 postoperatively compared to controls (3/15 versus 13/16, p < 0.001). The significance of these results is discussed.

The expression pattern of the Distal-less homeobox-containing gene Dlx-5 in the developing chick limb bud suggests its involvement in apical ectodermal ridge activity, pattern formation, and cartilage differentiation

Here we report the isolation from a chick limb bud cDNA library of a cDNA that contains the full coding sequence of chicken Dlx-5, a member of the Distal-less (Dlx) family of homeobox-containing genes that encode homeodomains highly similar to that of the Drosophila Distal-less gene, a gene that is required for limb development in the Drosophila embryo. The expression pattern of Dlx-5 in the developing chick limb bud suggests that it may be involved in several aspects of limb morphogenesis. Dlx-5 is expressed in the apical ectodermal ridge (AER) which directs the outgrowth and patterning of underlying limb mesoderm. During early limb development Dlx-5 is also expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the mid-proximal posterior margin that corresponds to the posterior necrotic zone. These mesodermal domains of Dlx-5 expression roughly correspond to the anterior and posterior boundaries of the progress zone, the group of highly proliferating undifferentiated mesodermal cells underneath the AER that will give rise to the skeletal elements of the limb and associated structures. The AER and anterior and posterior mesodermal domains of Dlx-5 expression are regions in which the homeobox-containing gene Msx-2 is also highly expressed, suggesting that Dlx-5 and Msx-2 might be involved in regulatory networks that control AER activity and demarcate the progress zone. In addition, Dlx-5 is expressed in high amounts by the differentiating cartilaginous skeletal elements of the limb, suggesting it may be involved in regulating the onset of limb cartilage differentiation.

Expression of type-X collagen in osteoarthritis

The present study was undertaken to examine how osteoarthritis affects the expression of type-X collagen, a hypertrophic chondrocyte-specific collagen in articular cartilage. A well characterized sheep polyclonal antiserum, as well as three mouse monoclonal antibodies against canine type-X collagen, was used to immunolocalize type-X collagen in human and canine joints. Its expression in osteoarthritic cartilage was altered in several locations. In the canine osteoarthritic joints, type-X collagen increased in and just above the zone of calcified cartilage and was present diffusely throughout the calcified matrix. In both the human and canine cartilage, type-X collagen was localized around cell clones in the transitional zone of cartilage. This is surprising, since that region of the cartilage does not calcify and one of the proposed roles of type-X collagen is in mineralization. Thus, the osteoarthritic process may damage the matrix in the superficial layer and induce changes leading to the expression of the hypertrophic chondrocyte phenotype.

Tibial-talar dislocation without fracture: treatment principles and outcome

The incidence of tibial-talar dislocations without fracture is unknown and has been sparsely reported in the literature. The diagnosis of the injury is straightforward with the appropriate examination and roentgenograms. Good to excellent results can be achieved with open or closed dislocations treated by closed reduction and immobilization for 4-6 weeks. Although open dislocations require irrigation, debridement, and possibly delayed closure, controversy exists with regard to acute ligament repair. Because good to excellent results are possible without acute ligament repair, and delayed repair on reconstruction can be accomplished with good outcomes, we recommend treating these injuries without ligament repair.

Obstetric patients who select and those who refuse medical students' participation in their care

PURPOSE

To assess attitudes and expectations of obstetric patients toward the involvement of medical students in their care.

METHOD

At the Medical Center Hospital of Vermont in 1991, questionnaire responses were collected from 222 obstetric patients who had been assisted by clerkship students from the University of Vermont College of Medicine and 78 patients who had refused the participation of students. The responses were analyzed for differences in demographic backgrounds, prior hospital experiences, and general expectations of student involvement, using chi-square, two-tailed t-tests and analysis of variance.

RESULTS

Both groups of respondents consisted primarily of young, well-educated, married women, who appear to have made their decisions about student participation by balancing their personal needs and their sense of altruism. For example, 61% of those who had refused the participation of students ranked the desire for privacy as their primary reason, whereas 73% of those who had accepted student participation ranked as their primary reason the desire to contribute to a student's education. Although both groups of patients expected the students to perform few clinical procedures, the patients who had refused student participation expected the students to be more involved in patient care than did the patients who had allowed participation. Of the 25% of the patients who had had students involved in prior pregnancy care, those who had currently refused student participation had less positive views of prior student care.

CONCLUSION

Patients' needs for privacy, past experiences with student care, and expectations of student performance should be considered to ensure the respectful incorporation of student involvement in obstetric care.

Intercondylar notch width and the risk for anterior cruciate ligament rupture. A case-control study in 46 female handball players

We measured the intercondylar notch of the femur in female handball players from radiographs of 20 players with previous unilateral anterior cruciate ligament injury, and 26 controls without injury. The groups were comparable regarding age, height, weight and level of performance. Intercondylar fossa radiographs were obtained in a posteroanterior axial position. The anterior opening of the intercondylar notch was narrower in the healthy knee of the injured group compared to the controls. There was an increased risk of anterior cruciate ligament injury associated with decreasing notch opening: female handball players with 17 mm or less anterior notch width were 6 times more susceptible to anterior cruciate ligament injury compared to players with wider notch width.

Distribution of the cdc2 gene product in normal tissues: an immunocytochemical study using four new monoclonal antibodies

The reproductive cycle in eukaryotic cells is partly controlled by the p34 protein kinase, the product of the cdc2 gene. We report here the tissue reactivity of four new anti-cdc2 monoclonal antibodies in relation to the known proliferation markers Ki-67 and JC1. In tissues where proliferation occurs, germinal centres in the tonsil, basal layers of tonsular epithelium and skin, cortex of the thymus, seminiferous tubules of the testis and epithelium of the colon, the anti-cdc2 antibodies gave positive nuclear staining as did the proliferation markers. The percentage of positive cells was, however, lower with the cdc2 antibodies. Given the role of the cdc2 gene at specific points of the cell cycle, these antibodies are potentially useful as markers of different phases of the cell cycle and may help to detect abnormalities in cell cycle control in disease.

O6-methylguanine in DNA inhibits replication in vitro by human cell extracts

To study the effects of methylation damage on DNA replication in vitro, the plasmid pSVori containing the SV40 origin of replication was reacted with N-methyl-N-nitrosourea and used as a substrate for SV40 T antigen dependent replication by HeLa cell extracts. The plasmid was methylated with a range of N-methyl-N-nitrosourea concentrations that introduced an average of 0.3-2.5 O6-methylguanine and equal amounts of 3-methyladenine lesions per DNA molecule. When methylated plasmid was incubated with extract of Mex-HeLaMR cells under conditions favoring DNA replication, an impairment of replication was observed as the accumulation of incompletely replicated form II plasmid molecules. These extracts simultaneously performed a T antigen independent, DpnI-sensitive DNA repair synthesis that increased with increasing DNA damage. Subtraction of this repair DNA synthesis revealed that methylation inhibited overall replication. At low levels of methylation (< or = 1 O6-methylguanine and < or = 1 3-methyladenine lesion per plasmid), inhibition was transient, while more extensive damage resulted in apparently irreversible inhibition of replication. Removal of O6-methylguanine by pretreatment of the methylated plasmid with purified human O6-methylguanine-DNA methyltransferase restored replication to almost normal levels. When the methylated plasmid was replicated by extracts of Mex+ HeLaS3 cells proficient in the repair of O6-methylguanine, a lower level of inhibition and less repair DNA synthesis was observed. The inhibition of DNA synthesis and the stimulation of repair DNA synthesis are thus both largely due to the presence of O6-methylguanine in DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of the domains in cyclin A required for binding to, and activation of, p34cdc2 and p32cdk2 protein kinase subunits

The binding of cyclin A to p34cdc2 and p32cdk2 and the protein kinase activity of the complexes has been measured by cell-free translation of the corresponding mRNA in extracts of frog eggs, followed by immunoprecipitation. A variety of mutant cyclin A molecules have been constructed and tested in this assay. Small deletions and point mutations of highly conserved residues in the 100-residue "cyclin box" abolish binding and activation of both p34cdc2 and p32cdk2. By contrast, large deletions at the N-terminus have no effect on kinase binding and activation, until they remove residues beyond 161, where the first conserved amino acids are found in all known examples of cyclin A. At the C-terminus, removal of 14 or more amino acids abolishes activity. We also demonstrate that deletion of, or point mutations, in the cyclin A homologue of the 10-residue "destruction box," previously described in cyclin B (Glotzer et al., 1991) abolish cyclin proteolysis at the transition from M-phase to interphase.

Effect of sodium chloride on transport of bacteria in a saturated aquifer material

Determinations were made of the influence of NaCl concentration, cell density, and flow velocity on the transport of Pseudomonas sp. strain KL2 through columns of aquifer sand under saturated conditions. A pulse-type boundary condition was used. The experiments were conducted by using 0.3-m-long Plexiglas columns with an internal diameter of 0.05 m. When a 1-h pulse of a 0.01 M NaCl solution containing 10(8) cells per ml was added at a flow rate of 10(-4) m s-1, the bacterial density in the effluent never exceeded 2.2% of the density of cells added, and only 1.5% of the bacteria passed through the aquifer material. In contrast, when the bacteria were applied in distilled water, the relative cell density in the effluent approached 100%, and 60% of the bacteria were transported through the aquifer solids. Under these conditions, the breakthrough of Pseudomonas sp. strain KL2 was slower than chloride. When the flow rate was 2.0 x 10(-4) m s-1, the cell density in the effluent reached 7.3% of that added in 0.01 M NaCl solution, but only 3.9% of the bacteria were transported through the aquifer particles. On the other hand, the density in the effluent approached 100% of that added in deionized water, and 77% of the added bacteria were recovered. When the density of added cells was 10(9) cells per ml at a flow rate of 10(-4) m s-1, the densities in the effluent reached 70 and 100% of those added in salt solution and deionized water, respectively, and 44 and 57% of the bacteria were transported through the aquifer solids.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental mutagens that induce the adaptive response to alkylating agents in Escherichia coli

Many microorganisms exhibit an adaptive response to mutagenic alkylation damage. In Escherichia coli the response is regulated by the inducible Ada protein. A sensitive immunoassay employing two anti-Ada monoclonal antibodies has been developed here to monitor low levels of induction of the Ada protein. This protein was detected in non-induced E. coli which contained an average of two molecules of Ada per cell. The occurrence of the adaptive response in bacteria signals the existence of an ecological niche in which cells are exposed to direct-acting methylating compounds, but the structure and identity of these agents are unknown. Using the immunoassay to search for possible candidates, a number of methylating agents and precursors of such agents have been investigated. Carbamyl phosphate and methylamine yield N-methylurea, which reacts subsequently with nitrite to generate the strong inducer N-methyl-N-nitrosourea. The antibiotic streptozotocin also is a potent inducer of the adaptive response. Moreover, the abundant environmental mutagen methyl chloride acts as an inducer.

Genetic and immunochemical analysis of mutant p53 in human breast cancer cell lines

The expression of the tumour suppressor gene p53 was analysed in 11 human breast cancer cell lines by immunohistochemistry, immunoprecipitation and cDNA sequencing. We used a panel of anti-p53 monoclonal antibodies for cell staining and found abnormalities in every case. Eight of the cell lines produce a form of p53 which can be immunoprecipitated by the monoclonal antibody PAb240 but not by PAb1620. In the murine system PAb240 only immunoprecipitates mutant p53. We sequenced p53 cDNA directly from four of the PAb240 positive cell lines using asymmetric PCR templates. All four contained missense mutations in p53 RNA, with no detectable expression of the wild type sequence. Different residues were affected in each cell line, but all the mutations changed amino acids conserved from man to Xenopus. These results imply that as in the murine system, the PAb240 antibody reliably detects a wide variety of p53 mutations and that these mutations have a common effect on the structure of p53. Immunohistochemical data suggest that p53 mutation is the commonest genetic alteration so far detected in primary breast cancer.

A data-based approach to diet questionnaire design and testing

A self-administered diet history questionnaire has been developed for epidemiologic and clinical use. Both the food list and the nutrient values to be associated with it were developed using dietary data from 11,658 adult respondents to the Second National Health and Nutrition Examination Survey (NHANES II). Food items were selected on the basis of their contribution to total population intake of energy and each of 17 nutrients in the NHANES II data, and represent over 90% of each of those nutrients. Associated nutrient composition values were determined from the NHANES II database using frequency of consumption data in that survey. Portion sizes to be associated with each food item were derived from observed portion size distributions in NHANES II, based on three-dimensional models. The resulting food list and its corresponding brief data base, when used to calculate nutrients from a diet record, yielded correlations of r greater than 0.70 with the more detailed method. Field administration produced mean values comparable to national data.

Cellular targets for SV40 large T-antigen

SV40 virus infection is able to induce tumours in newborn hamsters and to transform a wide range of eukaryotic cells in in vitro culture. This is achieved by integration of the viral DNA into the host cell DNA and expression of the virus-encoded Large T-antigen. The expression of Large T, a 708 amino acid phosphoprotein, is required both to induce and maintain the transformed state. The Large T protein initiates viral DNA synthesis and regulates viral transcription, apparently by binding in a specific manner to viral DNA sequences at and near the viral origin of replication. SV40 Large T also affects cellular DNA synthesis and transcription and this may account for its oncogenic activity. A novel immunochemical procedure has permitted the isolation of cellular DNA sequences occupied by SV40 Large T in the chromatin of SV40 transformed cells. Some of the cellular sequences contain high affinity binding sites for SV40 Large T, and hybridize to messenger RNAs expressed in SV40 transformed but not in normal cells. A second type of cellular target for Large T is the cell coded p53 protein that it binds to and stabilizes. A range of monoclonal antibodies to p53 has been isolated and characterized. They demonstrate that p53 is in the cytoplasm of normal cells but is located in the nucleus of transformed cells. One of the antibodies recognizes an epitope on p53 that is stabilized or induced by binding to Large T. Further studies on the T-p53 protein complex have been facilitated by constructing bacterial plasmids that direct the synthesis of substantial quantities of Large T-beta-galactosidase and p53-beta-galactosidase fusion proteins in bacteria. The results are discussed in the context of our current knowledge of oncogene action.

Secondary infection of rat lungs with Pasteurella pneumotropica after Kilham rat virus infection

Lung congestion was observed after an outbreak of Kilham rat virus infection (KRV) in a rat colony, previously free of all rat viruses. A high proportion of congested lungs contained Pasteurella pneumotropica suggesting that KRV might have caused primary damage to the alveoli (hitherto not recorded) which allowed the secondary bacterial colonization. Experimental infection of rats with KRV caused acute damage to the lung alveoli. Since KRV infection is very common in animal facilities it could therefore be a significant agent in the development of respiratory disease.

Comparison of alkaline phosphatase and horseradish peroxidase conjugated antisera in the ELISA test for antibodies to reovirus 3, mouse hepatitis and Sendai viruses

The method of enzyme-linked immunoadsorbent assay (ELISA) has been applied to the detection of antibodies to reovirus 3, Sendai virus and mouse hepatitis virus (type 1), and the serological response of mice after infection has been followed for 28 days to investigate the earliest appearance of ELISA titres. This has been compared to the appearance of haemagglutination-inhibiting and complement-fixing antibodies.

Alkaline phosphatase conjugated antiserum produces the most sensitive and convenient ELISA for the murine viruses examined.

Prevalence of indigenous viruses in laboratory animal colonies in the United Kingdom 1978-1979

Compared with the results of the previous serological survey of 1976-1977, it can be seen that mouse hepatitis virus is still prevalent in the mouse colonies and that corona viruses of rats are also common. The prevalence of Sendai virus has increased considerably. However, the prevalence of Reo 3 virus appeared to have decreased, although this may be the results of the different test used.