Clinical utility of skin cancer and melanoma risk scores for population screening: TRoPICS study

BACKGROUND

Screening for skin cancer can be cost-effective if focused on high-risk groups. Risk prediction tools have been developed for keratinocyte cancers and melanoma to optimize advice and management. However, few have been validated in a clinical setting over the past few years.

OBJECTIVES

To assess the clinical utility of risk assessment tools to identify individuals with prevalent skin cancers in a volunteer-based screening clinic.

METHODS

Participants were adults presenting for a skin check at a volunteer-based skin cancer screening facility. We used previously published tools, based on questionnaire responses, to predict melanoma and keratinocyte cancers [KCs; basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)] and classified each participant into one of five risk categories. Participants subsequently underwent a full skin examination by a dermatologist. All suspicious lesions were biopsied, and all cancers were histopathologically confirmed.

RESULTS

Of 789 people who presented to the clinic, 507 (64%) consented to the study. Twenty-two BCCs, 19 SCCs and eight melanomas were diagnosed. The proportion of keratinocyte cancers diagnosed increased according to risk category from <1% in the lowest to 24% in the highest risk category (P < 0.001). Subtype analysis revealed similar proportionate increases in BCC or SCC prevalence according to risk category. However, a similar proportion of melanoma cases were detected in the low-risk and high-risk groups.

CONCLUSION

The risk prediction model for keratinocyte cancers can reliably identify individuals with a significant skin cancer burden prior to a skin examination in the community setting. The prediction tool for melanoma needs to be tested in a larger sample exposed to a wider range of environmental risk factors.

A prospective study evaluating the integration of a multifaceted evidence-based medicine curriculum into early years in an undergraduate medical school

BACKGROUND

The importance of ensuring medical students are equipped with the skills to be able to practice evidence-based medicine (EBM) has been increasingly recognized in recent years. However, there is limited information on an effective EBM curriculum for undergraduate medical schools. This study aims to test the feasibility of integrating a multifaceted EBM curriculum in the early years of an undergraduate medical school. This was subsequently evaluated using the validated Fresno test and students' self-reported knowledge and attitudes as they progressed through the curriculum.

METHODS

EBM was integrated horizontally and vertically into the curriculum into the first 2 years of undergraduate medical school. First year medical students were recruited to participate in the study. The 212-point Fresno test was administered along with a locally developed questionnaire at baseline before EBM teaching in year one and at the end of EBM teaching in year two.

RESULTS

Thirty-one students participated at baseline and 55 students participated at the end of second year EBM teaching. For the 18 students who completed the Fresno at both time points, the average score increased by 38.7 marks (p < 0.001) after EBM teaching. Students felt confident in formulating clinical questions and in critically appraising journal articles after EBM teaching. EBM was perceived to be important to their future practice as a doctor and for improving patient outcomes at both time points.

CONCLUSIONS

It has been feasible to integrate a multifaceted, EBM curriculum from the first year of an undergraduate medical program. Early evaluation of the curriculum using the Fresno test has shown a significant increase in students' EBM knowledge. The curriculum also demonstrated an increase in students' perceptions of the clinical relevance of EBM in their developing practice.

Effect of Therapeutic and Supratherapeutic Doses of Vonoprazan on the QT/QTc Interval in a Phase I Randomized Study in Healthy Subjects

This phase I, randomized, 4-period, 4-sequence, double-blind, active- and placebo-controlled, crossover study assessed the effects of vonoprazan on the QT/QTc interval in healthy subjects. Subjects received single oral doses of vonoprazan 40 mg, vonoprazan 120 mg, moxifloxacin 400 mg (positive control/open label), and placebo. The primary end point was time-matched, placebo-corrected, baseline-adjusted mean Fridericia-corrected QT interval (ddQTcF). Of 64 subjects (mean age, 37.8 years; 50% male), 63 received all four regimens. One subject discontinued due to nondrug-related adverse event of tonsillitis. Assay sensitivity was established; lower bound of the one-sided 95% confidence interval (CI) for ddQTcF was >5 ms between 1.5 and 12 h following moxifloxacin administration. For both doses of vonoprazan, the one-sided upper 95% CI ddQTcF did not exceed 10 ms. There was no correlation between plasma vonoprazan concentrations and increases in ddQTcF. Vonoprazan was well tolerated. No severe adverse events/deaths were reported. (European Clinical Trials Database Registry: 2011-004003-20.).

Comparative epidemiology of Chlamydia trachomatis infection among men attending sexually transmitted disease clinics with and without indication for testing

Understanding the epidemiology of Chlamydia trachomatis infection in men without indication for testing (without symptoms, signs, or a report of sexual contact with an infected partner) is of crucial importance to reduce the heavy burden of this infection, particularly because this group of men is not usually offered testing in different clinical settings. Using electronic medical records of two STD clinics in Connecticut, 2000–02, this study identified the risk factors of C. trachomatis infection in men with and without indication for testing. In both groups, men who were younger than 30, African-American, or had a prior history of C. trachomatis infection were significantly more likely to be infected. Since a system for routine reproductive health care of young men does not currently exist, health-care providers need to promote an increased awareness of C. trachomatis infection among their male patients who are at increased risk of infection.

Randomised clinical trial: safety, tolerability, pharmacokinetics and pharmacodynamics of repeated doses of TAK-438 (vonoprazan), a novel potassium-competitive acid blocker, in healthy male subjects

BACKGROUND

TAK-438 (vonoprazan) is a potassium-competitive acid blocker that reversibly inhibits gastric H(+) , K(+) -ATPase.

AIM

To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of TAK-438 in healthy Japanese and non-Japanese men.

METHODS

In two Phase I, randomised, double-blind, placebo-controlled studies, healthy men (Japan N = 60; UK N = 48) received TAK-438 10-40 mg once daily at a fixed dose level for 7 consecutive days. Assessments included safety, tolerability, pharmacokinetics and pharmacodynamics (intragastric pH).

RESULTS

Plasma concentration-time profiles of TAK-438 at all dose levels showed rapid absorption (median Tmax ≤2 h). Mean elimination half-life was up to 9 h. Exposure was slightly greater than dose proportional, with no apparent time-dependent inhibition of metabolism. There was no important difference between the two studies in AUC0-tau on Day 7. TAK-438 caused dose-dependent acid suppression. On Day 7, mean 24-h intragastric pH>4 holding time ratio (HTR) with 40 mg TAK-438 was 100% (Japan) and 93.2% (UK), and mean night-time pH>4 HTR was 100% (Japan) and 90.4% (UK). TAK-438 was well tolerated. The frequency of adverse events was similar at all dose levels and there were no serious adverse events. There were no important increases in serum alanine transaminase activity. Serum gastrin and pepsinogen I and II concentrations increased with TAK-438 dose.

CONCLUSIONS

TAK-438 in multiple rising oral dose levels of 10-40 mg once daily for 7 days was safe and well tolerated in healthy men and caused rapid, profound and sustained suppression of gastric acid secretion throughout each 24-h dosing interval. Clinicaltrials.gov identifiers: NCT02123953 and NCT02141711.

Risk of epithelial ovarian cancer in asymptomatic women with ultrasound-detected ovarian masses: a prospective cohort study within the UK collaborative trial of ovarian cancer screening (UKCTOCS)

OBJECTIVE

To estimate the risk of primary epithelial ovarian cancer (EOC) and slow growing borderline or Type I and aggressive Type II EOC in postmenopausal women with adnexal abnormalities on ultrasound.

METHODS

This was a prospective cohort study in the ultrasound group of the UK Collaborative Trial of Ovarian Cancer Screening of postmenopausal women with ultrasound-detected abnormal adnexal (unilocular, multilocular, unilocular solid and multilocular solid, solid) morphology on their first scan. Women were followed up through the national cancer registries and by postal questionnaires. Absolute risks of EOC and borderline, Type I and Type II EOC within 3 years of initial scan were calculated.

RESULTS

Of 48 053 women who underwent ultrasound examination and had complete scan data, 4367 (9.1% (95% CI, 8.8-9.3%)) had abnormal adnexal morphology. Median follow-up was 7.09 (25(th) -75(th) centiles, 6.03-7.92) years. Forty-seven (32 borderline or Type I, 15 Type II) were diagnosed with EOC. The overall absolute risk of EOC associated with abnormal adnexal morphology was 1.08% (95% CI, 0.79-1.43%); for borderline and Type I it was 0.73% (95% CI, 0.5-1.03%); and for Type II it was 0.34% (95% CI, 0.33-0.79%). In the subgroup (n = 741) with solid elements (unilocular solid, multilocular solid and solid) overall absolute risk was 4.45% (95% CI, 3.08-6.20%), for borderline and Type I it was 3.1% (95% CI, 1.9-4.6%) and for Type II it was 1.3% (95% CI, 0.6-2.4%). 11 982 women had both ovaries visualized and normal annual scans throughout the 3-year follow-up period. In this group, no borderline or Type I and eight Type II cancers were diagnosed.

CONCLUSION

Asymptomatic postmenopausal women with ultrasound-detected adnexal abnormalities with solid elements have a 1 in 22 risk for EOC. Despite the higher prevalence of Type II EOC, the risk of borderline or Type I cancer in women with ultrasound abnormalities seems to be higher than does the risk of Type II cancer. This has important immediate implications for patients with incidental adnexal findings as well as for any future ultrasound-based screening.

Maternal asthma and placental morphometry: effects of severity, treatment and fetal sex

Asthma is the most common respiratory disease to complicate pregnancy. Although adverse effects on the fetus have been documented, there is a paucity of information regarding the effects of asthma, and its treatment, on placental morphology. The aim of this study was to test for volumetric differences in placental composition between non-asthmatic pregnancies and those associated with maternal asthma grouped according to asthma severity and glucocorticoid (GC) treatment. Each placenta was weighed and random samples of tissue were fixed in formalin-saline, embedded in wax and analysed by design-based stereology. Volume densities of parenchymal compartments (peripheral villi and maternal intervillous space) and residual non-parenchyma were estimated by test point counting and converted to absolute volumes by taking into account placental size. Relative and absolute lengths of villi and capillaries were also estimated and used to derive secondary quantities related to villous capillarization and maturation. Between-group comparisons were drawn by two-way analysis of variance with group and fetal sex as the principal factors. Compared to non-asthmatic controls, asthmatics had reduced absolute volumes of fetal capillaries which was most marked in those with moderate/severe asthma and those using low and high doses of inhaled GCs. Changes in the total length and mean cross-sectional area of capillaries and peripheral villi were also observed. Lengths were greater in mild asthmatics and lowest in those with high GC usage. Calibre areas were lower in mild asthmatics and villous calibres in the high GC group were greater than those in asthmatics not taking GCs. Those making greatest use of inhaled GCs also had villi which were hypovascularized in terms of capillary:villus length ratios. The findings suggest that the morphometric differences in fetoplacental vascularity are likely to be due to the effects of asthma and use of inhaled GCs rather than the effects of maternal or fetal hypoxic stress.

Condom effectiveness for prevention of Chlamydia trachomatis infection

BACKGROUND/OBJECTIVES

A growing body of evidence is increasingly demonstrating the effectiveness of condoms for sexually transmitted infection (STI) prevention. The purpose of the present analysis was to provide a disease specific estimate for the effectiveness of condoms in preventing Chlamydia trachomatis infection while controlling for known exposure to infection.

METHODS

Condom effectiveness for C trachomatis was estimated using a medical record database from a public sexually transmitted disease clinic (n = 1455). Clients were classified as having known exposure to C trachomatis if they presented to the clinic as a contact to an infected partner.

RESULTS

Among clients with known exposure, 13.3% of consistent condom users were diagnosed with C trachomatis infection compared to 34.4% of inconsistent condom users (adjusted odds ratio = 0.10; 95% CI: 0.01 to 0.83). Among clients with unknown exposure, there was no observed protective effect of condoms.

CONCLUSIONS

This study provides further evidence that condoms are effective in preventing C trachomatis infection by reporting a disease specific estimate and restricting analyses to individuals with known exposure.

Variation in the CTLA4/CD28 gene region confers an increased risk of coeliac disease

Susceptibility to coeliac disease involves HLA and non-HLA-linked genes. The CTLA4/CD28 gene region encodes immune regulatory T-cell surface molecules and is a strong candidate as a susceptibility locus. We evaluated CTLA4/CD28 in coeliac disease by genetic linkage and association and combined our findings with published studies through a meta-analysis. 116 multiplex families were genotyped across CTLA4/CD28 using eight markers. The contribution of CTLA4/CD28 to coeliac disease was assessed by non-parametric linkage and association analyses. Seven studies were identified that had evaluated the relationship between CTLA4/CD28 and coeliac disease and a pooled analysis of data undertaken. In our study there was evidence for a relationship between variation in the CTLA4/CD28 region and coeliac disease by linkage and association analyses. However, the findings did not attain formal statistical significance (p = 0.004 and 0.039, respectively). Pooling findings with published results showed significant evidence for linkage (504 families) and association (940 families): p values, 0.0001 and 0.0014 at D2S2214, respectively, and 0.0008 and 0.0006 at D2S116, respectively. These findings suggest that variation in the CD28/CTLA4 gene region is a determinant of coeliac disease susceptibility. Dissecting the sequence variation underlying this relationship will depend on further analyses utilising denser sets of markers.

Prospective survey of childhood inflammatory bowel disease in the British Isles

The incidence of inflammatory bowel disease in children in western countries may be rising. Since there is no prospective national data on the incidence of inflammatory bowel disease in the UK and Republic of Ireland (ROI), we undertook a prospective survey to determine this incidence. The incidence during 1998 and 1999 was 5.2/100,000 per year in children aged younger than 16 years. Those from an Asian background were over-represented and more likely to have ulcerative colitis.

Contribution of the MHC region to the familial risk of coeliac disease

Susceptibility to coeliac disease is genetically determined by possession of specific HLA-DQ alleles, acting in concert with one or more non-HLA linked genes. The pattern of risk seen in sibs and twins in coeliac disease is most parsimonious with a multiplicative model for the interaction between the two classes of genes. Based on a sib recurrence risk for coeliac disease of 10% and a population prevalence of 0.0033, the sib relative risk is 30. To evaluate the contribution of the MHC region to the familial risk of coeliac disease, we have examined haplotype sharing probabilities across this region in 55 coeliac disease families. Based on these probabilities the sib relative risk of coeliac disease associated with the MHC region is 3.7. Combining these results with published data on allele sharing at HLA, the estimated sib relative risk associated with the MHC region is 3.3. Therefore, the MHC genes contribute no more than 40% of the sib familial risk of coeliac disease and the non-HLA linked gene (or genes) are likely to be the stronger determinant of coeliac disease susceptibility.

The relationship between staff burnout/distress and interactions with residents in two residential homes for older people

OBJECTIVE

The main hypothesis was that staff burnout/distress would be negatively associated with the quantity and quality of social interactions between staff and residents. The subsidiary hypothesis hypothesis was that 'perceived involvement in decision-making' among staff would be positively associated with the quantity and quality of staff-resident interactions.

DESIGN

Cross-sectional and within-group. Standardized self-report questionnaires completed by staff; and non-participant, time-sampling observation and coding of staff-resident interactions. SETTING. Two independent (not-for-profit) residential care homes for older people in the UK.

PARTICIPANTS

18 out of 24 residential workers completed questionnaires.

MEASURES

The 12-item General Health Questionnaire (GHQ-12); the Maslach Burnout Inventory (MBI); the Perceived Involvement Personal Questionnaire (PIPQ); and the Quality of Interactions Schedule (QUIS).

RESULTS

Staff who reported higher levels of personal accomplishment (ie lower levels of burnout on the personal accomplishment subscale) exhibited significantly more staff-resident interactions; and staff who perceived more involvement in decisions relating to their work showed significantly fewer negative staff-resident interactions. Staff distress, emotional exhaustion and depersonalization were not found to be significantly related to the quantity or quality of staff resident interactions.

CONCLUSIONS

The results provide some support for the hypotheses. It appears that levels of personal accomplishment and perceived involvement in decision-making among staff may significantly influence the quantity and quality of staff-resident interactions in residential settings. However, the causal relationships are uncertain, and replication of these findings is required in other contexts.

Carcinoma of the tonsil: prognostic factors

OBJECTIVES

This study was conducted to provide a review of the prognostic factors of tonsillar carcinoma.

DESIGN

A retrospective analysis.

SETTING/PATIENTS

Patients with squamous cell carcinoma of the tonsil, treated in Northern Alberta, at the Cross Cancer Institute from 1975 to 1995 were analyzed using a population-based, head and neck cancer registry. There were 102 patients, 73 male and 29 female, ranging in age from 35 years to 83 years, with a mean of 60 years. The clinical stages were T1: 5 patients; T2: 27 patients, T3: 33 patients; T4: 11 patients; and Tx: 3 patients. The nodal stages were N0: 33 patients, N1: 26 patients; N2: 34 patients, N3: 7 patients; Nx: 2 patients.

METHOD

The patients were treated with various modalities: surgery alone: 2 patients; surgery plus radiation: 26 patients; radiation treatment alone: 61 patients; and others: 13 patients. Patients were classified according to the UICC TNM 1992 criteria. The overall 5-year Kaplan-Meier survival in our series was 39%. The cause-specific 4-year survival was 57%. Various prognostic factors and their impact on survival were studied.

RESULTS

On univariate analysis, the following factors were found to be significant. Age < 50 vs. > 50 (p = .02); endophytic growth pattern vs. exophytic growth of the primary (p = .01); ulcerated lesions vs. nonulcerated lesions (p = .000); various T stages (p = .003); clinical extension vs. no extension of primary disease (p = .02); combined modality of treatment (surgery and radiation treatment) had the best chance of survival compared to radiation treatment alone (p = .03). Nodal stages N0 vs. N+ disease (p = .2); sex of the patient, female vs. male (p = .83); and dose of radiation treatment < 5000 cGy vs. > 5000 cGy (p = .41) were found not to be significant. When the above significant factors were stratified according to the stage of the disease, only two were significant; ulcerated lesions vs. nonulcerated lesions (p = .04), and the modality of treatment chosen (e.g., radiation alone vs. radiation plus surgery) (p = .02).

CONCLUSIONS

In this series of patients, combined-modity approach using surgery and radiation treatment was found to be the best way to treat carcinoma of the tonsil. However, each treatment strategy should be individualized taking into account various prognostic factors.

GST-lamin fusion proteins act as dominant negative mutants in Xenopus egg extract and reveal the function of the lamina in DNA replication

A cDNA encoding Xlamin B1 was cloned from a whole ovary mRNA by RT-PCR. GST-lamin fusion constructs were generated from this cDNA by first creating convenient restriction sites within the Xlamin B1 coding sequence, using PCR directed mutagenesis, and then sub-cloning relevant sequences into pGEX-4T-3. Two expression constructs were made, the first, termed delta 2+ lacked sequences encoding the amino-terminal 'head domain' of lamin B1 but included sequences encoding the nuclear localization signal sequence (NLS). The second expression construct, termed delta 2-, lacked sequences encoding the amino-terminal 'head domain' as well as sequences encoding the NLS. Purified fusion proteins expressed from these constructs, when added to egg extracts prior to sperm pronuclear assembly, formed hetero-oligomers with the endogenous lamin B3. The delta 2+ fusion protein prevented nuclear lamina assembly but not nuclear membrane assembly. The resulting nuclei were small (approximately 10 microns in diameter), did not assemble replication centers and failed to initiate DNA replication. When the delta 2- fusion protein was added to egg extracts prior to sperm pronuclear assembly, lamina assembly was delayed but not prevented. The resulting nuclei although small (approximately 12 microns), did form replication centers and initiated DNA replication. When added to egg extracts after sperm pronuclear assembly was completed delta 2+, but not delta 2-, entered the pre-formed nuclei causing lamina disassembly. However, the disassembly of the lamina by delta 2+ did not result in the disruption of replication centers and indeed these centres remained functional. These results are consistent with the hypothesis that lamina assembly precedes and is required for the formation of replication centers but does not support those centers directly.

Building a virtual reality temporal bone dissection simulator

The temporal bone is one of seven bones that comprise the human skull, and has an intimate relationship with many vital structures. Anatomically, its three-dimensional relationships make it one of the most challenging areas for surgeons to understand and master. In addition, the temporal bone contains minute structures that are among the most sophisticated and delicate in the human body. These structures include the cochlea and vestibular organs, which are responsible for hearing and balance; the middle ear, including the ossicles, which conduct acoustic energy to the cochlea; and the facial nerve, which is responsible for controlling the muscles of facial expression, and contributes to the sensation of taste. Additionally, the temporal bone forms a major portion of the skull base, and has intimate relationships to vital structures including the carotid artery, jugular vein, cerebral cortex, brainstem, and cranial nerves. Surgical procedures performed on the temporal bone include: procedures to eradicate chronic and acute infections; procedures to remove malignant and benign tumors within the temporal bone, from the skull base, or from the posterior cranial fossa; procedures to restore the hearing mechanism; procedures to eliminate balance disorders; and procedures to correct congenital anomalies. For surgeons-in-training, and even surgeons-in-practice, mastery of the anatomy of the temporal bone and the many complex approaches necessary to treat patients takes years of focused endeavor. This is typically accomplished through the dissection of human cadaver temporal bones, which are scarce, and require a dedicated laboratory facility. Efforts are currently underway to develop a realistic simulator for temporal bone procedures. Users immersed in the simulator will interact with a three-dimensional temporal bone, derived from patient-specific data, using a haptic interface to simulate traditional surgical procedures. Feedback from experts in otologic surgery will be built into the system for additional instruction. This presentation will include an overview of the application being developed, a report of its current state of development, and plans for the future.

Nuclear lamina and nuclear matrix organization in sperm pronuclei assembled in Xenopus egg extract

Nuclear lamina and matrices were prepared from sperm pronuclei assembled in Xenopus egg extracts using a fractionation and extraction procedure. Indirect immunofluorescence revealed that while chromatin was efficiently removed from nuclei during the extraction procedure, the distribution of lamins was unaffected. Consistent with this data, the amount of lamin B3, determined by immunoblotting, was not affected through the extraction procedure. Nuclear matrices were visualised in DGD sections by TEM. Within these sections filaments were observed both at the boundary of the nucleus (the lamina) and within the body of the nucleus (internal nuclear matrix filaments). To improve resolution, nuclear matrices were also prepared as whole mounts and viewed using field emission in lens scanning electron microscopy (FEISEM). This technique revealed two distinct networks of filaments. Filaments lying at the surface of nuclear matrices interconnected nuclear pores. These filaments were readily labelled with monoclonal anti-lamin B3 antibodies. Filaments lying within the body of the nuclear matrix were highly branched but were not readily labelled with antilamin B3 antibodies. Nuclear matrices were also prepared from sperm pronuclei assembled in lamin B3 depleted extracts. Using FEISEM, filaments were also detected in these preparations. However, these filaments were poorly organised and often appeared to aggregate. To confirm these results nuclear matrices were also observed as whole mounts using TEM. Nuclear matrices prepared from control nuclei contained a dense array of interconnected filaments. Many (but not all) of these filaments were labelled with anti-lamin B3 antibodies. In contrast, nuclear matrices prepared from "lamin depleted nuclei' contained poorly organised or aggregated filaments which were not specifically labelled with anti-lamin B3 antibodies.

Xenopus lamin B3 has a direct role in the assembly of a replication competent nucleus: evidence from cell-free egg extracts

Xenopus egg extracts which assemble replication competent nuclei in vitro were depleted of lamin B3 using monoclonal antibody L6 5D5 linked to paramagnetic beads. After depletion, the extracts were still capable of assembling nuclei around demembranated sperm heads. Using field emission in lens scanning electron microscopy (FEISEM) we show that most nuclei assembled in lamin B3-depleted extracts have continuous nuclear envelopes and well formed nuclear pores. However, several consistent differences were observed. Most nuclei were small and only attained diameters which were half the size of controls. In a small number of nuclei, nuclear pore baskets, normally present on the inner aspect of the nuclear envelope, appeared on its outer surface. Finally, the assembly of nuclear pores was slower in lamin B3-depleted extracts, indicating a slower overall rate of nuclear envelope assembly. The results of FEISEM were confirmed using conventional TEM thin sections, where again the majority of nuclei assembled in lamin B3-depleted extracts had well formed double unit membranes containing a high density of nuclear pores. Since nuclear envelope assembly was mostly normal but slow in these nuclei, the lamin content of 'depleted' extracts was investigated. While lamin B3 was recovered efficiently from cytosolic and membrane fractions by our procedure, a second minor lamin isoform, which has characteristics similar to those of the somatic lamin B2, remained in the extract. Thus it is likely that this lamin is necessary for nuclear envelope assembly. However, while lamin B2 did not co-precipitate with lamin B3 during immunodepletion experiments, several protein species did specifically associate with lamin B3 on paramagnetic immunobeads. The major protein species associated with lamin B3 migrated with molecular masses of 102 kDa and 57 kDa, respectively, on one-dimensional polyacrylamide gels. On two-dimensional O'Farrell gels the mobility of the 102 kDa protein was identical to the mobility of a major nuclear matrix protein, indicating a specific association between lamin B3 and other nuclear matrix proteins. Nuclei assembled in lamin B3-depleted extracts did not assemble a lamina, judged by indirect immunofluorescence, and failed to initiate semi-conservative DNA replication. However, by reinoculating depleted extracts with purified lamin B3, nuclear lamina assembly and DNA replication could both be rescued. Thus it seems likely that the inability of lamin-depleted extracts to assemble a replication competent nucleus is a direct consequence of a failure to assemble a lamina.

Management of infantile polyposis syndrome

A boy with generalised infantile polyposis syndrome is reported to highlight the difficulties in management. Despite attempts to reduce polyp mass by regular endoscopic polypectomy, daily transfusions of blood products, and a trial of the non-steroidal anti-inflammatory agent sulindac, his condition gradually deteriorated and he died of septicaemia.

Evidence for the direct involvement of lamins in the assembly of a replication competent nucleus

Monoclonal antibodies linked to paramagnetic immunobeads (Dynabeads) have been used to investigate the distribution of lamin B3 in fractions of Xenopus egg extracts. Lamin B3 behaved as if it were completely soluble and did not co-precipitate with membrane fractions. Sperm pronuclei assembled in lamin depleted egg extracts were compared to pronuclei assembled in mock depleted extracts by field emission in-lens electron scanning microscopy (FEISEM). This technique revealed that the surface structures of the nuclear envelopes, including nuclear pores, appeared to be identical, indicating that lamin depletion does not affect nuclear envelope assembly. One-dimensional and two-dimensional gel electrophoresis was used to analyze soluble proteins co-precipitated with lamin B3 on Dynabeads. Our results indicate that two major species (molecular mass: 105 kDa and 57 kDa) specifically co-precipitate with lamin B3 as well as several minor species. At least three proteins which co-precipitate with lamin B3 were identified as nuclear matrix proteins. Lamin B3 was separated from these proteins and re-inoculated into lamin depleted extracts. This resulted in partial rescue of both lamina assembly and DNA replication. These results imply that lamin B3 is directly involved in the assembly of structures required for the initiation of DNA replication.

Multicenter comparative study of cochlear implants: surgical results

Cochlear implant surgery by a group of experienced surgeons proceeded without major complications. Computed tomography scans tended to underestimate cochlear obstruction, but a drill-out was infrequently required if the scan was apparently normal.

Evidence for the direct involvement of lamins in the assembly of a replication competent nucleus

Monoclonal antibodies linked to paramagnetic immunobeads (Dynabeads) have been used to investigate the distribution of lamin B3 in fractions of Xenopus egg extracts. Lamin B3 behaved as if it were completely soluble and did not co-precipitate with membrane fractions. Sperm pronuclei assembled in lamin depleted egg extracts were compared to pronuclei assembled in mock depleted extracts by field emission in-lens electron scanning microscopy (FEISEM). This technique revealed that the surface structures of the nuclear envelopes, including nuclear pores, appeared to be identical, indicating that lamin depletion does not affect nuclear envelope assembly. One-dimensional and two-dimensional gel electrophoresis was used to analyze soluble proteins co-precipitated with lamin B3 on Dynabeads. Our results indicate that two major species (molecular mass: 105 kDa and 57 kDa) specifically co-precipitate with lamin B3 as well as several minor species. At least three proteins which co-precipitate with lamin B3 were identified as nuclear matrix proteins. Lamin B3 was separated from these proteins and re-inoculated into lamin depleted extracts. This resulted in partial rescue of both lamina assembly and DNA replication. These results imply that lamin B3 is directly involved in the assembly of structures required for the initiation of DNA replication.

Colon carcinoid tumors. A population-based study

PURPOSE

The aim of our investigation was to evaluate the clinical presentation of patients with carcinoid tumors of the colon and to estimate the survival and potential prognostic factors of this tumor type.

METHODS

A population-based study was performed using data from the Alberta Cancer Registry between 1964 and 1988 (inclusive). The clinical records and the pathologic material of eligible patients were reviewed. Survival was estimated both as crude survival and with the Kaplan-Meier method.

RESULTS

During the 25-year study period (1964-1988), 36 true carcinoid tumors of the colon were diagnosed in Alberta. Carcinoids of the ileocecal region and of the rectum were excluded from the study. The average age at time of diagnosis was 68.4 years; there were 20 males and 16 females. Symptoms (abdominal pain, diarrhea, weakness, anorexia) occurred late in the course of the disease: 64 percent of the lesions were in Dukes D stage and 22 percent were Dukes C at diagnosis. Only one patient presented with a malignant carcinoid syndrome. Lesions occurred most frequently in the cecum (39 percent), followed by transverse and sigmoid colon. Most of the patients were managed surgically. The perioperative mortality rate was with 22 percent, which is quite high. The average size of the lesions was 5.8 (range, 2-10) cm, and most tumors (31/36) had invaded the pericolic fat. The most common immunohistochemical pattern was argentaffin/argyrophil negative and neuron-specific enolase positive. Two-year and five-year actuarial (Kaplan-Meier) survival was 34 percent and 26 percent, respectively. Survival for carcinoids of the colon was significantly lower compared with carcinoids of the rectum or appendix, and with colon adenocarcinomas. Size of the tumor and tumor invasion into the muscularis propria--the two major histopathologic prognostic factors for carcinoids of the gastrointestinal tract--were not found to influence survival significantly. Rather, tumor stage, histologic pattern, tumor differentiation, nuclear grade, and mitotic rate were found to significantly influence the survival rate.

CONCLUSION

Carcinoid tumors of the colon are extremely rare tumors, diagnosed late in the course of the disease, and they carry a bad prognosis. Prognostic factors are tumor stage, histologic pattern, differentiation, nuclear grade, and mitotic rate of the tumor.

Breast cancer diagnosis and survival in women with and without breast implants

The stage at diagnosis and the survival experience of 41 women who developed breast cancer after cosmetic breast augmentation were compared with those of all other patients with breast cancer (n = 13,246) diagnosed in Alberta from 1973 to 1990 (inclusive). The tumors in women with breast implants were smaller (65.9 percent < or = 2 cm) as compared with the tumors in women without implants (34.1 percent < or = 2 cm), but lymph node and distant metastases were equally frequent in the two groups. The distribution of tumor histologic types did not differ significantly between women with or without implants. Women who had an implant were younger at diagnosis of breast cancer compared with women with breast cancer and no breast implants. The relative 5- and 10-year survival rates did not differ significantly between the two groups, and the Kaplan-Meier survival estimate also was similar. It is concluded that women with breast implants in whom breast cancer develops are not diagnosed in a later stage and do not experience an impaired survival as compared with breast cancer patients without implants.

Nuclei that lack a lamina accumulate karyophilic proteins and assemble a nuclear matrix

Xenopus egg extracts, which support nuclear assembly and DNA replication in vitro, were physically depleted of lamin B3 using monoclonal antibodies linked to magnetic beads. Depleted extracts were still able to support nuclear envelope assembly around demembranated sperm heads but the resulting pronuclei lacked a lamina and were unable to initiate semiconservative DNA replication or to assemble replicases, confirming previous data. Immunoblotting analysis of isolated nuclei and nuclear matrix fractions indicated that lamin-depleted nuclei still accumulated nucleoporins and PCNA. Furthermore, the rate of PCNA uptake was identical in lamin-depleted and control nuclei. However, neither the nucleoporins nor the PCNA was associated with nuclear matrix fractions. The major protein components of sperm pronuclear matrix fractions were characterized by two-dimensional gel electrophoresis. Of these proteins only three out of 22 species, other than the lamins, were significantly reduced in lamin-depleted nuclei, indicating that these nuclei do assemble a nuclear matrix.

Effect of different chloride infusion rates on plasma base excess during neonatal parenteral nutrition

Routine biochemical monitoring of parenterally fed newborn infants revealed plasma chloride levels which were higher than widely quoted reference ranges. The parenteral nutrition solutions were reformulated to reduce the chloride infusion rate. In a historically controlled study, 28 infants receiving the original formulation were compared with 31 infants receiving the new formulation. The mean plasma chloride level was 4.8 mmol/l lower in the new formulation group than in the original formulation group (95% confidence interval 2.5-7.2 mmol/l). The mean base excess level was 3.1 mmol/l higher in the new formulation group than in the original formulation group (95% confidence interval 1.9-4.8 mmol/l). A reduction in the chloride load by using acetate salts can be safely achieved and may decrease the plasma chloride levels and decrease acidosis during the first seven days of life.

The effect of somatostatin on small intestinal transport in intractable diarrhoea of infancy

It has been reported that somatostatin may be an effective antisecretory agent in a range of conditions causing severe secretory diarrhoea. In many children, intractable diarrhoeal illnesses result in significant morbidity and mortality. In a group of seven children with secretory diarrhoea, the effect of i.v. infusion of somatostatin (3.5 micrograms/kg stratum plus 3.5 micrograms/kg/h) on the net mucosal flux of salt and water was assessed using an in vivo steady-state perfusion technique. In one of the seven children who had evidence of deranged mucosal secretion and preserved villus function, somatostatin infusion resulted in a moderate reduction in secretion. In the remaining six, it had little or no beneficial effect. Somatostatin did not alter the rate of glucose absorption.

A survey of basic resuscitation knowledge among resident paediatricians

A telephone questionnaire was undertaken to evaluate the knowledge of resident paediatricians on the subject of the basic resuscitation of the acutely sick child. The questionnaire was targeted at 88 resident paediatricians in hospitals accepting paediatric emergencies in four health regions. Outcome was measured as a correct response to questions based on several emergency scenarios and on the confidence expressed of basic resuscitation knowledge. The subject of emergency management of the child with a compromised upper airway was poorly answered with 40/73 (55%) resident paediatricians suggesting an incorrect endotracheal tube size for an 8 year old child. Fluid management was also deemed unsatisfactory with only 36/73 (49%) providing adequate transfusion secondary to haemorrhagic shock. In addition only 19/73 (26%) mentioned the intraosseous route as a means of obtaining vascular access in a child in extremis. Confidence of the knowledge of basic resuscitation of children was low among resident paediatricians with only 30/73 (41%) expressing confidence and 69/73 (94%) expressing a desire for more formal training in paediatric resuscitation. Resident paediatricians are usually the key personnel in the management of very sick children. This survey demonstrates a low level of basic resuscitation knowledge among resident paediatricians of all grades that must be remedied at a local and national level.

Breast augmentation: a risk factor for breast cancer?

BACKGROUND

A relation between breast augmentation and the subsequent risk of breast cancer has been postulated. Since an estimated 2 million women in the United States alone have received breast implants, even a small increase in the risk of breast cancer could have considerable public health consequences.

METHODS

We performed a population-based nonconcurrent cohort-linkage study. All women in Alberta, Canada, who underwent cosmetic breast augmentation from 1973 through 1986 were included in the implant cohort (n = 11,676). This cohort was compared with the cohort of all women in Alberta in whom a first primary breast cancer was diagnosed (n = 13,557). The expected number of breast-cancer cases in the implant cohort was estimated by applying age-specific and calendar year--specific incidence rates of breast cancer (obtained from the Alberta Cancer Registry) to the implant cohort. Standardized incidence ratios were calculated by dividing the observed by the expected number of breast-cancer cases in the implant cohort.

RESULTS

Forty-one patients with implants were subsequently found to have breast cancer. The expected number was 86.2. The standardized incidence ratio was thus 47.6 percent, significantly lower than expected (P less than 0.01). The average length of follow-up in the implant cohort was 10.2 years, and the average length of time from breast augmentation to the diagnosis of breast cancer was 7.5 years.

CONCLUSIONS

Women who undergo breast augmentation with silicone implants have a lower risk of breast cancer than the general population. This finding suggests that these women are drawn from a population already at low risk and that the implants do not substantially increase the risk.

Identification and characterization of a gene at D10S94 in the MEN2A region

We have identified a candidate for the gene responsible for multiple endocrine neoplasia type 2A (MEN 2A) at D10S94 in proximal 10q11.2. An evolutionarily conserved sequence from D10S94 was used as a probe to isolate cDNAs corresponding to a gene that we have termed mcs94-1. The gene spans 11 kb and has an unmethylated CpG island at its 5' end. The mcs94-1 transcript is approximately 2.4 kb in length and is widely expressed. It encodes a putative 415-amino-acid polypeptide that is similar in sequence to nucleolin, an abundant nucleolar protein. Mcs94-1 was examined as a candidate for MEN2A through nucleotide sequence analysis of mcs94-1 exons from an MEN 2A chromosome and its wildtype homologue from an MEN 2A patient. The major portion of the expressed mcs94-1 sequence was examined. No differences in sequence were found between the two alleles.

Optical isomers of rocastine and close analogues: synthesis and H1 antihistaminic activity of its enantiomers and their structural relationship to the classical antihistamines

The enantiomers of 2-[2-(dimethylamino)ethyl]-3,4-dihydro-4-methylpyrido[3,2-f]-1,4- oxazapine-5(2H)-thione (rocastine) and two of its more potent analogues were prepared with an enantiomeric purity of greater than 99.9%. The antihistaminic activity of these compounds was assessed by their ability to block histamine-induced lethality in guinea pigs and to inhibit [3H]mepyramine binding to guinea pig cortex. In this series, compounds having the R configuration at the 2-position are at least 300 times more potent than the S isomers. Conformational analysis and molecular modeling suggest that rocastine can adopt a conformation in which the pyridine ring, ether oxygen, and protonated amine functions are positioned similarly to the corresponding elements of the probable binding conformers of some of the more classical antihistamines. This conformation, boatlike in the oxazepine ring with the side chain quasi-equatorial and folded back toward the ring, is the likely binding conformer at the histamine H1 receptor, and the available structure-activity relationship data is consistent with this interpretation.

Correlation between c-erbB-2 amplification and risk of recurrent disease in node-negative breast cancer

Drawing upon the comprehensive population-based Northern Alberta Breast Cancer Registry containing 704 patients with histologically negative axillary lymph nodes who have been followed for 5-16 years, we have undertaken a retrospective case-control study to evaluate the utility of genomic amplification of specific protooncogenes [c-erbB-2 (nee HER-2/neu), c-erbA, c-myc, int-2, and hst-1] as predictive indicators of clinical outcome in node-negative disease. To this end, 115 women with node-negative breast cancer who had recurred at any time up to 16 years posttreatment (cases) were matched pairwise for appropriate clinicopathological variables (size of primary tumor, menopausal state, estrogen receptor status, anniversary year of treatment, and patient age) with a second group of 115 women (controls) selected from a cohort of 502 node-negative patients who had not relapsed during long-term follow-up. Tumor DNA extracted from archival formalin-fixed, paraffin-embedded tissue blocks were analyzed for protooncogene copy number by slot-blot hybridization. Taking a gene copy number of 3 as the cutoff, 27 of the 230 tumor samples examined contained from 3- to 22-fold elevation in c-erbB-2 genomic equivalents. Twenty-one of the 27 tumors amplified for c-erbB-2 were derived from cases and 6 from controls, signifying that 18% of the node-negative patients who had relapsed harbored excessive copies of the protooncogene in their malignant tissue compared to only 5% for the patients who had remained in remission. Accordingly, the occurrence of amplification of c-erbB-2 proved to be a statistically significant predictor of poor prognosis, especially disease-free interval (P = 0.006). Moreover, this genetic alteration appeared to be independent of and to have greater predictive power than most commonly used prognostic factors. Our findings also indicated that as a clinical test, measurement of c-erbB-2 amplification suffers from low sensitivity; however, when greater than 6 gene copies are present, the test has a positive predictive value for recurrence of 70%. Concurrent analysis of tumor DNA blots with probes for the other four protooncogenes examined revealed that their amplification, which others have reported to arise often, especially in node-positive disease, was seldom found even in our high-risk case group (2-3%). In short, our data strongly suggest that amplification of c-erbB-2 may contribute to the pathogenesis of some forms of node-negative breast cancer and thus may serve as a useful genetic marker to identify a subset of high-risk patients.

Family history of ovarian cancer patients: a case-control study

In order to obtain a more correct estimate of cancer incidence in relatives of cases with ovarian cancer and relatives of age-matched controls, information was obtained on family size, date of birth and death, and cancer history. The average total number of first degree (parents and siblings) and some second degree (uncles and aunts) relatives for cases (15.03) and controls (15.22) is very similar. Of all the relatives 33% were Alberta residents or decreased in Alberta after 1966 so they could be checked in the population based Alberta Cancer Registry. There was a 14% level of error in the information provided, 9% for first degree relatives and 25% for uncles and aunts. The errors included missed malignancies, benign lesions quoted as malignancies, incorrect cancer site and inaccurate dates of birth, diagnosis or death. Results were compared between the relatives of cases and controls using either all relatives or only Alberta residents. For the Alberta residents, expected numbers of malignancies were calculated by age/sex-specific person/years and age/sex-specific incidence rates. The number of relatives with ovarian cancer is significantly higher in cases than in controls in both data sets, but shows a limited relative risk of 2.61 (95% confidence limits 1.12-1.59). Clustering of cases is exceptional, only one patient out of 197 had two relatives with ovarian cancer and this was a case with a larger than average total number of relatives. In conclusion, although there is a significantly higher incidence of ovarian cancer in the family history of cases than of controls, it is not very common and only nine out of 197 cases (4.6%) presented with such background.

Speech tracking in the evaluation of a multichannel cochlear prosthesis

Individual speech tracking data were analyzed in relation to other variables in 11 adult users of the Nucleus multichannel cochlear implant. Patients were categorized according to postoperative speech tracking results. The resultant groups could also be differentiated on the basis of postoperative MAC scores, surgeon's rating of overall success, and duration of deafness before implantation. The speech tracking paradigm appears to be a useful technique for the evaluation of performance with a cochlear prosthesis.

Suprathreshold abnormalities of the stapedius reflex in acoustic tumor: a series of case reports

Suprathreshold morphologic characteristics of the acoustic stapedius reflex are reported for five subjects with acoustic tumor. Results support the hypothesis that changes in suprathreshold morphology may be more sensitive to acoustic tumor than conventional reflex threshold and decay measures. Both the afferent relative amplitude index (AI) and measures of sequential variability of individual waveforms appear to be especially promising.

Stapedius reflex to electrical stimulation in a patient with a cochlear implant

In a patient with a multichannel cochlear implant, it was possible to demonstrate stapedius reflex contraction to intracochlear electrical stimulation. Using a standard immittance measurement technique, characteristics of the electrically evoked reflex were compared to analogous characteristics of the acoustically evoked reflex. Latency-intensity functions were similar for the two modes of excitation, but reflex waveform morphology and amplitude growth functions were different.