Achieving success with the silicone expander for overacting superior obliques

PURPOSE

To report the results of and complications with silicone expander surgery for the overacting superior oblique.

METHODS

A total of 26 patients with bilateral overaction of the superior oblique and A-pattern strabismus and 5 patients with unilateral overacting superior oblique secondary to inferior oblique palsy were treated with a 7 mm silicone expander. Care was taken not to enter the sub-Tenon's space.

RESULTS

The group that underwent bilateral superior oblique surgery had an average preoperative pattern of 37.42 diopters (D) and an average correction of 35.37 D. Three patients had a severe unilateral postoperative inflammatory incident that was successfully treated with oral and topical corticosteroids. One of these patient developed Brown's syndrome. Another patient, who had no postoperative inflammatory incident, also developed Brown's syndrome. In these 4 patients, the sub-Tenon's space was inadvertently entered during surgery.

CONCLUSION

The silicone expander surgery has a very high success rate in treating the A-pattern associated with the bilateral overacting superior oblique. This procedure also works well for the unilateral superior oblique that overacts owing to an inferior oblique palsy. No cyclotorsion symptoms occurred after this surgery. However, 4 patients had complications because the sub-Tenon's space was exposed during surgery. With this procedure, there is a learning curve to obtain the skill not to enter the sub-Tenon's space.

The relation between inter-twin birth weight discordance and total twin birth weight

OBJECTIVE

We tested the hypothesis that the frequency of growth discordance among twins is not related to the uterine capacity for carrying twins.

METHOD

We counted and compared the frequencies of birth weight discordance of more than 25% in an unlike-sexed twin cohort (n = 1244) and in a population-based twin cohort (n = 7570) across the deciles of the total twin birth weight (twin A + twin B) distribution. The birth order of the heavier twin was noted.

RESULTS

Similar frequencies of discordant pairs were found in both cohorts (11% and 12%, respectively; Mantel-Haenszel chi2 test: P = .131, odds ratio (OR) 0.9, 99% confidence interval (CI) 0.67, 1.11; Woolf test for heterogeneity: two-tailed P = .472). In the discordant pairs, twin A was considerably more often the heavier twin in all birth weight deciles (unlike-sexed cohort: P < 10(-8), OR 5.9, 99% CI 3.0, 11.7; population-based cohort: P < 10(-8), OR 3.1, 99% CI 2.3, 4.0), and in both cohorts (inter-cohort difference: P = .109, OR 1.4, 99% CI 0.83, 2.32). Both cohorts showed a similar nonlinear trend: given that X = decile order, discordance decreased as a function of 22.0 - 6.54 ln[X] for the unlike-sexed twins cohort and 23.0 - 8.18 ln[X] for the population-based cohort, with r values of 0.967.

CONCLUSION

The more favorable the uterine milieu for carrying twins, the smaller the likelihood of discordant twin growth. Birth order of the heavier twin appears to be an integral part of the discordance phenomenon. The similarity of the cohorts suggests that these conclusions are valid for both like and unlike-sexed twins.

Exploring the barriers to cervical screening in an urban Canadian setting

Cervical cancer is potentially one of the most preventable cancers. The benefits of cervical screening come to those who are actually screened. Despite the known value of cervical screening, a significant number of women do not avail themselves of the procedure. This study examined the barriers to cervical screening in an urban Canadian setting. Focus group methodology was used to explore the perspectives of socioeconomically disadvantaged women regarding their access to health care. The sessions were tape-recorded, and subsequent content analysis revealed four broad themes: being able to talk with doctors is important; being treated as a person is important; finding answers to many questions about cancer is important; and having a Pap test is uncomfortable. Implications for practice and program design were highlighted.

Subsequent quality of life for children irradiated for a brain tumor before age four years

BACKGROUND

We wanted to evaluate survival and functional morbidity following radiation treatment of brain tumors in children less than 4 years old.

PROCEDURE

Outcome was evaluated for 222 children who were less than 4 years old when they were irradiated at University of Toronto Centres, 1958-1995. The status of the survivors with regard to focal neurological defects, vision, hearing, and education at last follow-up was recorded. In 23 adult survivors older than 21 years at last follow-up, information was obtained with regard to higher education, occupation, and living arrangements.

RESULTS

The overall 10-year survival rate was 40%, not significantly different than the 45% for 776 4-16-year-olds with irradiated brain tumors treated at the same institutions. Forty-five percent of the survivors had no major focal neurological, visual, or hearing defects. There were no major differences in the frequencies of these criteria or of schooling between 0-2- and 2-4-year-olds. Among adult survivors, older than 21 at last follow-up, 26% successfully completed higher education, 31% were in full-time employment, and 37% had never been employed. For medulloblastoma, the 5-year survival rate was 61% for 30 children less than 3 years old and treated from 1975-1995. This compared favorably with recent reports of survival following primary chemotherapy with delayed or omitted radiation treatment.

SUMMARY

Radiation treatment of a young child with a brain tumor was associated with cure in 1 of every 3 patients. Unfortunately, quality of life for many survivors was not good. Only one of every 3 adult survivors was able to have a normal life-style. This shortfall was the result of focal neurological defects which were present from the time of first treatment, and of the long-term effects of radiation treatment.

CONCLUSIONS

The search for less toxic treatment remains appropriate, but is experimental and researchers must recognize that there may be a trade-off between morbidity and mortality.

Transmission of Chlamydia trachomatis and Neisseria gonorrhoeae among men with urethritis and their female sex partners

Transmission of Chlamydia trachomatis and Neisseria gonorrhoeae among infected men and their female sex partners was examined using a design enhancing the likelihood that spread was directed from men to women. Chlamydia culture-negative specimens were examined using DNA amplification tests. Infection rates in women exposed to male sex partners with Chlamydia only were 65% (20/31) and with gonorrhea only were 73% (33/45). Infection of women by either agent was not influenced by the number of sexual exposures to or coinfection in men. There was a 98% (40/41) concordance of N. gonorrhoeae isolates among partners by auxotype and serovar. Chlamydia isolates were serotyped using ELISA and immunofluorescence testing and confirmed by nested polymerase chain reaction: 50% (6/12) of men and 57% (8/14) of women yielded mixed serovars. Sixty-four percent of pairs (9/14) were infected with identical serovars and an additional 28% shared at least one serovar. Multiple serovars of C. trachomatis, but not of N. gonorrhoeae, were common in sex partners and exchanged frequently.

A dileucine motif in HIV-1 Nef is essential for sorting into clathrin-coated pits and for downregulation of CD4

Nef, a approximately 200 residue multifunctional regulatory protein of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV), interacts with components of host cell signal transduction and clathrin-dependent protein sorting pathways. The downregulation of surface CD4 molecules and major histocompatibility complex (MHC) class I antigens by Nef is believed to be important in AIDS pathogenesis [1-7]. Nef contains a globular core domain and two disordered segments--a myristylated arm at the amino terminus and a carboxy-terminal loop projecting from the globular core [8,9]. Here, we aimed to determine the sorting signals in HIV-1 Nef that were responsible for its involvement in the clathrin-mediated pathway. We found that a sequence in the carboxy-terminal disordered loop of Nef is essential for downregulation of CD4. This sequence resembles the dileucine motif, one of two well-characterized sorting signals that target membrane proteins to clathrin-coated vesicles. The dileucine-motif-containing segment of Nef bound directly and specifically to the beta-adaptin subunit of the clathrin adaptor complexes AP-1 and AP-2, which are responsible for recruiting sorted proteins into coated pits. Unlike wild-type Nef, a mutant form of Nef that lacked the dileucine motif did not localize to clathrin-coated pits and did not downregulate CD4 expression, although it could downregulate MHC class I surface expression. Thus, the dileucine motif in HIV-1 is required for CD4 downregulation and for interaction with clathrin adaptor complexes.

Factors which support effective worker participation in health and safety: a survey of New Jersey industrial hygienists and safety engineers

Strategies for increasing worker involvement in health and safety are widespread and have received emphasis in various OSHA reform proposals; however, much remains unknown about the effectiveness of these strategies. This paper draws on a survey of more than 400 New Jersey members of the American Industrial Hygiene Association (AIHA) and the American Society of Safety Engineers (ASSE) which addressed a broad range of issues relating to health and safety conditions and practices, including the use of worker or labor/management health and safety committees (HSCs) and worker health and safety representatives. Stepwise discriminant analysis was used to explore the relationships between effective participation and variables which describe worksites and potential health and safety resources and barriers. Effective strategies for involving workers appear to be conditional on a number of variables, most importantly on worker activism and the effective use of formal union negotiations. Findings are consistent with studies from both the U.S. and abroad which emphasize the role of unions in shaping opportunities for effective worker participation.

A comparison of physician and patient perspectives on unconventional cancer therapies

In two related studies about unconventional cancer therapies, patients and physicians were interviewed about their experiences and opinions. In this paper comparisons are made and implications discussed. There was general agreement among physicians and patients about the importance of providing access to information about unconventional approaches for interested patients. However, there were substantial differences in perspective on other issues, including: what constitutes 'unconventional', the helpfulness of typical physician responses to patients interested in or using unconventional therapies, the proper interface between practitioners of conventional and unconventional therapies, the reasons for communication problems (related to unconventional therapies) between physicians and patients, and the proper criteria for making decisions about unconventional therapies. Cancer specialists, family physicians and other health professionals need to look for ways to better understand and meet the needs of their patients with interests in unconventional approaches if they hope to preserve or improve relations.

Self-help groups

OBJECTIVE

To assess Ontario family physicians' attitudes toward, awareness of, and practices related to self-help groups in general and cancer self-help groups specifically.

DESIGN

Mailed survey using a modified Dillman method.

SETTING

Ontario family practices.

PARTICIPANTS

A random sample of 1500 Ontario members of the College of Family Physicians of Canada, of whom 949 responded. A total of 911 completed questionnaires were received, for an eligible response rate of 64%.

MAIN OUTCOME MEASURES

Physician demographics, practice characteristics; extent of awareness of self-help groups and their perceived value; attitudes toward self-help groups; practices related to interactions with patients about self-help groups.

RESULTS

Only 40.2% of respondents were aware of six or more self-help groups in their region; 56.8% were aware of at least one cancer self-help group. Discussions with patients about groups were reported as occurring "frequently" by 12% of respondents, who indicated they made referrals to an array of groups. Ratings of group helpfulness were relatively high (83.8% scoring 3, 4, or 5 on a 5-point scale, where 5 is "very helpful"). There were low ratings of potential harm (1% scoring 4 or 5 on a 5-point scale, where 5 is "very harmful"). Confidence intervals for proportions reported on in this paper were all within 4%.

CONCLUSIONS

Family physicians have predominantly positive attitudes about the potential benefits of self-help groups, and many are recommending groups to their patients.

Outcome analysis of rhabdomyosarcoma of the lower urinary tract

PURPOSE

Multimodal therapy has resulted in a high cure rate for genitourinary rhabdomyosarcoma. We propose that the strategy of induction chemotherapy followed by excision and reconstruction without radiotherapy may provide a high cure rate without the late sequelae of pelvic radiotherapy.

MATERIALS AND METHODS

We reviewed the records of 13 patients with a mean age of 3.3 years diagnosed with rhabdomyosarcoma of the urinary tract from 1986 to 1996. The primary site was the bladder in 4 cases and prostate in 9. After biopsy confirmation of the diagnosis patients were treated with chemotherapy and subsequent surgery, while radiotherapy was reserved for those with residual disease.

RESULTS

After induction chemotherapy 8 patients underwent tumor excision via an organ sparing approach, which involved radical prostatectomy and partial cystectomy with or without bladder augmentation. In 5 patients the final pathological analysis showed positive margins. Repeat surgery in 6 patients included complete cystectomy and urinary diversion in 2 who had positive margins and recurrence after radiotherapy, urethrectomy and continent diversion for positive margins in 1, partial cystectomy and continent diversion in 1, and radical prostatectomy, partial cystectomy and continent diversion in 1 with stage IV disease who had local recurrence. In the latter case ileocystoplasty had been performed for a small noncompliant bladder. Six patients with microscopic residual or metastatic disease received radiotherapy. At a mean followup of 5.6 years 11 patients are disease-free. Continence was preserved in all reconstructed cases. Erections were reported in 8 patients, and renal function was maintained in 10.

CONCLUSIONS

Our results suggest that urinary tract reconstruction may be safely performed at primary excision surgery, radiotherapy induced morbidity may be minimized by limiting radiotherapy to residual and metastatic disease, frozen section results may be false-negative, potency may be achieved and radiological disappearance of the tumor should be confirmed histologically.

Lack of cisplatin-ranitidine kinetic interactions: in vivo study in children, and in vitro study using dog renal brush border membrane vesicles

The interactions between cisplatin and organic ions have been extensively investigated in animal models for the potential to reduce cisplatin cellular uptake and resultant nephrotoxicity. To further investigate the beneficial interaction clinically, we studied the effects of the organic cation, ranitidine, on the renal handling of cisplatin in children. In parallel, we examined the effects of cisplatin on the uptake kinetics of organic cations and anions by brush border membrane vesicles (BBMV) prepared from dog renal cortex. The results indicate that: 1) there is no measurable effect of ranitidine on renal clearance of cisplatin in children; and 2) BBMV uptake of anionic p-aminohippurate, but not cationic N-methylnicotinamide, is inhibited by cisplatin at concentrations of <1 mM. These findings suggest that cisplatin may not share transport systems with organic cations to a clinically significant degree. Assuming that renal tubular transport is a prerequisite for cisplatin nephrotoxicity, the lack of apparent kinetic interactions between cisplatin and organic cations may preclude clinical use of organic cations as a modality to prevent cisplatin nephrotoxicity.

A conceptual design for cosmo-biology experiments in Earth's Orbit

A conceptual design was developed for a cosmo-biology experiment. It is intended to expose simulated interstellar ice materials deposited on dust grains to the space environment. The experimental system consists of a cryogenic system to keep solidified gas sample, and an optical device to select and amplify the ultraviolet part of the solar light for irradiation. By this approach, the long lasting chemical evolution of icy species could be examined in a much shorter time of exposure by amplification of light intensity. The removal of light at longer wavelength, which is ineffective to induce photochemical reactions, reduces the heat load to the cryogenic system that holds solidified reactants including CO as a constituent species of interstellar materials. Other major hardware components were also defined in order to achieve the scientific objectives of this experiment. Those are a cold trap maintained at liquid nitrogen temperature to prevent the contamination of the sample during the exposure, a mechanism to exchange multiple samples, and a system to perform bake-out of the sample exposure chamber. This experiment system is proposed as a candidate payload implemented on the exposed facility of Japanese Experiment Module on International Space Station.

Neuronal apoptosis induced by HIV-1 gp120 and the chemokine SDF-1 alpha is mediated by the chemokine receptor CXCR4

CXCR4, a seven transmembrane domain G-protein-coupled receptor for the Cys-X-Cys class of chemokines, is one of several chemokine receptors that can act as a co-receptor with CD4 for the human immunodeficiency virus (HIV-1) glycoprotein gp120 [1-3]. CXCR4 can mediate the entry of HIV-1 strains that specifically infect T cells, such as the IIB strain (see [4] for review). Recent reports indicate that gp120 can signal through CXCR4 [5] and it has been suggested that signal transduction, mediated by the viral envelope, might influence viral-associated cytopathicity or apoptosis [6]. Neuronal apoptosis is a feature of HIV-1 infection in the brain [7,8], although the exact mechanism is unknown. Here, we address the possible role of CXCR4 in inducing apoptosis using cells of the hNT human neuronal cell line; these cells resemble immature post-mitotic cholinergic neurons and have a number of neuronal characteristics [9-15]. We have previously shown that gp120 from the HIV-1 IIIB strain binds with high affinity to CXCR4 expressed on hNT neurons [15]. We now find that both IIIB gp120 and the Cys-X-Cys chemokine SDF-1 alpha can directly induce apoptosis in hNT neurons in the absence of CD4 and in a dose-dependent manner. To our knowledge, this is the first report of a chemokine and an HIV-1 envelope glycoprotein eliciting apoptotic responses through a chemokine receptor.

Direct and indirect estimates of HIV-1 incidence in a high-prevalence population

While the worldwide AIDS epidemic continues to expand, directly measured incidence data are difficult to obtain. Methods to reliably estimate human immunodeficiency virus type 1 (HIV-1) incidence from more easily available data are particularly relevant in those parts of the world where prevalence is rising in heterosexually exposed populations. The authors set out to estimate HIV-1 incidence in a population of heterosexual sexually transmitted disease clinic attendees in Trinidad who had a known high prevalence of HIV-1 subtype B. Over the period 1987-1995, HIV-1 incidence estimates from serial cross-sectional studies of HIV-1 prevalence, passive follow-up of clinic recidivists, modeling of early markers of HIV-1 infection (p24 antigen screening), and a cohort study of seronegative genital ulcer disease cases were compared. Measuring incidence density in the genital ulcer disease cases directly gave the highest estimate, 6.9% per annum. Screening for the detection of early HIV-1 markers yielded an incidence of 5.0% per annum, while estimating incidence from serial cross-sectional prevalence data and clinic recidivists gave estimates of 3.5% and 4.5% per annum, respectively. These results were found to be internally consistent. Indirect estimates of incidence based on prevalence data can give accurate surrogates of true incidence. Within limitations, even crude measures of incidence are robust enough for health planning and evaluation purposes. For planning vaccine efficacy trials, consistent conservative estimates may be used to evaluate populations before targeting them for cohort studies.

Cytological changes in endotracheal aspirates associated with chronic lung disease

Endotracheal aspirates taken serially from mechanically ventilated premature infants born at < 28 weeks gestation between March 1992 and August 1993 were studied to determine whether early cytological changes would be a good predictor of lung damage in infants who develop chronic lung disease (CLD). CLD was diagnosed if the infant required supplemental oxygen at 36 weeks corrected gestational age. Fifty-five infants were enrolled in the study, five died and of the 50 infants remaining, 17 (34%) developed CLD. The infants with CLD had a significantly lower gestation (25.5 +/- 1.8 (mean +/- 1 SD) versus 26.2 +/- 0.9 weeks, p < 0.05), significantly more required surfactant (14/17 vs. 16/33, p < 0.05) and were ventilated for a significantly longer period (43.3 +/- 26.6 vs. 19.3 +/- 12.8 days, p < 0.0001). Endotracheal aspirate cytology showed that infants with CLD had significantly more degenerated columnar epithelial cells on day 3 (p = 0.001), and more neutrophils on day 10 (p = 0.007). Though not predictive of CLD, cytological changes consistent with bronchial epithelial and pulmonary damage followed by an inflammatory response were found in the tracheal aspirates of a group of infants clinically diagnosed with CLD.

A survey of New Jersey industrial hygienists and safety engineers: health and safety conditions, practices, and priorities for OSHA reform

This study reports the results of an analysis of responses from more than 400 New Jersey industrial hygienists and safety engineers to a survey examining a wide range of health and safety conditions and practices. Findings are reported on a number of variables including the types and seriousness of safety and health hazards encountered at the respondents' work sites, perceived improvements in health and safety conditions, compliance with right-to-know requirements, the effectiveness of resources used in correcting hazards, and the barriers encountered in addressing hazardous conditions. The respondents were also asked to rank their priorities regarding 14 proposals for Occupational Safety and Health Administration (OSHA) reform. Opinion questions were scaled to reflect the respondent's sense of the importance of each variable. One finding of particular interest is that worker involvement in health and safety committees was perceived as an "effective" or "very effective" resource by more than one-half of the respondents. Changes in the Occupational Safety and Health Act that would strengthen requirements for worker participation were among the respondents' top priorities for OSHA reform.

Information needs of women with metastatic breast cancer

Eight focus groups involving women with metastatic breast cancer were held across Ontario over approximately 6 months in 1996-97. Prevalent themes identified during the sessions are reported under 2 broad dimensions: the women's expressed desire for information in specific content areas, and issues related to whether information can be either beneficial or harmful, depending on how it is provided. The women reported high needs for information, especially that which would relate to their situation. Perceived adequacy of information is closely linked to health professional engagement and care. Although the provision of information is important, the needs of these women for maintenance of hope and provision of interpersonal support and comfort are also critical.

Partnerships between self-help networks and health care facilities: the case of the Bayview Support Network

This article discusses the role of patients and their families as peer support providers to other patients, and as decision makers within organizations. We use as a model the Bayview Support Network, a self-help network at the Toronto-Sunnybrook Regional Cancer Centre. We review the benefits of partnership, costs, limitations and risks. A list of features that contribute to effective partnership is also provided.