Multifocal intraocular lenses

It has been 10 years since I implanted the first multifocal intraocular lens (IOL). Unfortunately, there has been a gradual lessening of commitment to this modality by the ophthalmic community. The most important single factor for this lack of interest despite the more than adequate available clinical data is the repeated moving of "goal posts" by the American FDA when a multifocal lens style nears premarket approval. The refractive multifocal lens styles of iolab (Claremont, CA), Stortz Ophthalmics (St. Louis, MO), Domilens (Lyon, France), and Amo with the diffractive multifocals of 3M (St. Louis, MO), and Pharmacia (Kalamazoo, MI) and their recent modifications are reviewed. Reports show that they generally give excellent visual results depending on whether a near or distance dominant lens is indicated. The foldable Amo Array SA40N provides a good distance dominant foldable lens for the surgeon performing small incisions and has a small but dedicated surgical following. Loss of contrast sensitivity at low-light levels remains a source of concern in certain professions and with certain lifestyles, and a report suggesting that many monofocal and multifocal patients do not achieve the standards set for night driving by the German Ophthalmic Society warrants further consideration. Development of a new accommodative IOL for small incision surgery is the only really new concept, and it will be interesting to see the results of independent reports. Spectacle dependence is considerably reduced with all the current multifocals when compared to monofocals, and for patients there are ample multifocal lens styles from which to choose. It is the author's opinion that more than 60% of the cataract population is currently suitable for multifocals if small incision surgery is performed. More multifocals would be used if price disparity with monofocals was reduced.     

Respiratory acidosis and subcutaneous emphysema during laparoscopic cholecystectomy

A case is presented of a healthy 69-yr-old woman who underwent elective laparoscopic cholecystectomy under general anaesthesia. As surgery proceeded she developed hypercapnia (arterial blood PaCO₂ = 100 mmHg) and a related respiratory acidosis (arterial blood pH 7.07). The cause was attributed to subcutaneous insufflation and absorption of CO₂, directly related to the surgical pneumoperitoneum.     

Family size, infections, and asthma prevalence in New Zealand children.

We conducted a prevalence case-control study to investigate the relation between family composition, infection, and development of asthma at age 7-9 years. Potential cases (399) and controls (398) were selected from the Wellington, NZ, arm of the International Study of Asthma and Allergies in Childhood, a population-based prevalence study. Further screening questions restricted cases to children with a diagnosis of asthma and current medication use (N = 233) and restricted controls to children without a history of wheezing and no diagnosis of asthma (N = 241). After controlling for confounders (including infections, atopy, and socioeconomic status), family size was strongly related to asthma. Having no siblings [prevalence odds ratio (POR) = 2.51; 95% confidence interval (CI) = 1.05-6.01] or one sibling (POR = 1.86; 95% CI = 1.14-3.03) was associated with an increased risk of asthma compared with having more than one sibling. Parent-reported rubeola infection (and possibly other similar viral exanthems) was independently associated with a decreased risk of asthma (POR = 0.48; 95% CI = 0.27-0.83), but reported pertussis infection (POR = 1.57; 95% CI = 0.58-4.24) and day care attendance in the first year of life (POR = 1.81; 95% CI = 0.93-3.51) were not strongly associated with increased risks of asthma.     

The New Zealand Socioeconomic Index: developing and validating an occupationally-derived indicator of socio-economic status

OBJECTIVE: Following revision of the international standard classification (ISCO88), to update and validate on health data an occupationally derived indicator of socio-economic status (SES) adapted to changing occupational and demographic conditions. METHOD: The development of the New Zealand Socioeconomic Index (NZSEI) is based on a 'returns to human capital' model of the stratification process and uses data from the 1991 New Zealand Census (n = 1,051, 926) to generate scores for 97 occupational groups. The construct validation of the scale is carried out on data from the 1992-93 nationwide Household Health Survey (n = 3,000) using three health indicators (self-assessed health, cigarette smoking, general practitioner visits). RESULTS: In general, the results are consistent with expected socio-economic patterns drawn from the literature for the three indicators. CONCLUSIONS: While further work is required on a number of methodological and conceptual issues, the NZSEI provides a robust, standardised and internationally comparable occupational scale of SES for both males and females in either full- or part-time employment. IMPLICATIONS: The NZSEI can be used on routinely collected occupational data. It has a clear conceptual rationale, updates existing SES scales, and provides a link to international standards in SES and occupational classification.     

Atypical post-translational modification and targeting of a Schistosoma mansoni surface receptor, a member of the transforming growth factor beta receptor family of cell surface receptors

The surface membrane of the intravascular parasite Schistosoma mansoni is composed of not one but two closely apposed lipid bilayers which overlie a syncytial cellular layer, known as the tegument or neodermis. To gain insights into how membrane proteins are transported to and displayed on this unusual surface structure, we have investigated the post-translational modification and targeting of SmRK-1, a receptor and type I membrane protein expressed on the parasite surface, using heterologous expression systems. While SmRK-1 enters the secretory pathway in these systems, our data indicate that the SmRK-1 N-terminal signal peptide is either not cleaved by signal peptidase or is only eleven amino acids long or less. Retention of the signal peptide is accompanied by N-linked glycosylation of an asparagine residue within the predicted signal peptide. The SmRK-1 signal peptide is not capable of directing another cytoplasmic protein to the secretory pathway, suggesting that the signal for insertion of the SmRK-1 extracellular domain into the endoplasmic reticulum resides elsewhere in the protein. Further, SmRK-1 is inefficiently transported to the cell surface in mammalian cells, suggesting that the schistosome neodermis possesses specialized systems for receptor targeting and localization.