The musculature and pupillary response of the great horned owl iris

There is considerable confusion in the literature regarding the nature of the musculature of the avian iris. The most commonly held view is that both the sphincter and dilator are striated. The iris of the Great Horned Owl (Bubo virginianus) has a complex iridial musculature consisting of three circumferential components (a myoepithelium, smooth muscle and striated muscle) and two radial components (a well-developed myoepithelium and a few striated fibers). On the basis of the anatomy and relative development of these components, and a quantitative analysis of the pupillary reflex, it is proposed that the circumferential striated muscle is the primary pupillary constrictor and radial myoepithelium is the primary dilator. The annular band of smooth muscle may play an important role in maintaining pupillary size.

Age-related changes in the basement membrane of the human corneal epithelium

An ultrastructural evaluation and morphometric analysis of the basement membrane of the normal human corneal epithelium in 45 specimens from subjects ranging in age from 17 weeks of gestation to 93 years was conducted. It was found that thickening of the corneal epithelial basement membrane takes place by two main processes: continued membrane deposition (forming unilaminar membranes) and membrane reduplication (forming multilaminar membranes). During the fetal period and for the first two decades of postnatal life, membrane thickening occurs exclusively by continued membrane deposition so that these unilaminar membranes increase in thickness by 3 nm each year. Membrane reduplication in focal areas after the age of 20 and with increasing frequency and greater involvement of the membrane thereafter was observed. Since anchoring fibrils and hemidesmosomes are important in the adhesion of the epithelium to Bowman's layer, we paid particular attention to these structures. We could find no relation between hemidesmosome content and the formation of reduplicated or multilaminar membranes. However, the anchoring fibrils become disrupted with increasing age, and the membrane thickness exceeds fibril length in some specimens. It is proposed that this phenomenon effectively blocks linkage between the anchoring fibrils and Bowman's layer. The evidence for cell injury and death as a promoter of membrane reduplication was compared to the evidence for a primary deterioration of the basement membrane.

High Pressure Liquid Chromatographic Determination of Oxazepam Dosage Forms: Collaborative Study

A reverse phase high pressure liquid chromatographic method for the determination of oxazepam in tablets and capsules was collaboratively studied by 9 laboratories. Collaborators were supplied with 6 samples that included synthetic and commercial formulations. Tablet and capsule composites are diluted with methanol and filtered. Oxazepam is determined at 254 nm by using a C18 column. Mean recoveries of oxazepam from synthetic tablet and capsule formulations were 97.2 and 99.0%, respectively. Mean coefficients of variation for tablets and capsules ranged from 1.85 to 2.86%. The method has been adopted official first action.

Instrumentation for analysis of continuous neck rotation

Novel instrumentation is described which enables continuous recording of human neck rotation as a subject goes about normal activities during the day. Subsequent computer analysis and display allows for easy investigation and assessment of results. The system can measure rotation over a range of +90 degrees with an accuracy of ±6 degrees. Initial clinical results indicate that the system should assist in the study of neck problems.

Age-related effects on the threshold, psychophysical function, and pleasantness of menthol

Participants were 20 persons half of whom were 18 to 26 years of age (M = 21) and half of whom were over 65 years (M = 75). All were ambulatory, noninstitutionalized, and reported good to excellent health. The stimulus was menthol delivered in air to the nostrils. Threshold was measured using the up-down staircase method. Intensity and pleasantness were measured by magnitude estimation. The average threshold for the elderly participants was significantly higher than for young participants. The median slope of the intensity function was steeper by a factor of two for younger adults. The average pleasantness functions were steeper for the younger persons. Finally, although the younger adults found menthol less pleasant with repeated exposure, the elderly persons showed no effect of exposure. The results suggest that the average, healthy elderly person's odor/trigeminal world differs from that of the young adult. Further experiments are exploring the relative contributions of olfactory, trigeminal, and cognitive factors in producing this change.

Localization of human immunoglobulin kappa light chain variable region genes to the short arm of chromosome 2 by in situ hybridization

The genes for human immunoglobulin kappa light chains have been localized in normal lymphocyte and fibroblast chromosomes by in situ hybridization of probes from cloned DNA fragments of the kappa variable region locus. The localization was achieved by counting grains (after autoradiography) over chromosomes in a number of karyotypes. The variable region gene probes hybridized in a cluster on a region of the chromosome 2 short arm close to the centromere (2cen leads to p12). This location was confirmed in lymphocytes from a balanced translocation carrier 46XXt (2; 16) (q13; q22). Our results show that human kappa light chain genes are located in the region of the break point observed in specific chromosomal translocations associated with Burkitt lymphoma.

Age-related changes in trabecular meshwork cellularity

To investigate whether alterations in the cellular component of the trabecular meshwork occur with age, we evaluated trabecular meshwork cellularity and absolute cell number, using specimens obtained from patients ranging in age from newborn to 81 years. We obtained reproducible, quantitative measurements of these parameters, using montages of 1 micrometer meridional sections. A progressive decrease in cellularity (58%) and absolute cell number (47%) in the trabecular meshwork occurred over the 81-year period studied. Regression analysis suggested that the decrease in cellularity and cell number is linear function of age, resulting from a loss of approximately 0.58% of all cells per year. This change in cellularity parallels that seen in the corneal endothelium. implying that trabecular cells, like corneal endothelial cells, may have a limited reparative capacity.

Anaemia in old age: a study of prevalence and causes

A study of the prevalence and causes of anaemia in 559 randomly selected people aged 65 years and over living in their own home, in residential homes or in hospitals was made. In the population 65 years and over 7.1 percent were found to have a haemoglobin level less than 120 g/l and 2.5 percent a haemoglobin level less than 110/gl. The majority who were anaemic suffered from multiple and chronic diseases. The dietary intake of the anaemic was similar to those with a normal haemoglobin. In women aged 80 years or more, the haemoglobin level decreased significantly with age. Women had lower haemoglobin levels than men.

Chromosomal localization of a single copy gene by in situ hybridization--human beta globin genes on the short arm of chromosome 11

1. The localization of the beta globin genes by in situ hybridization to fixed chromosomes is described. 2. The probe used was a [3H]cRNA copy of a genomic clone containing in total 4.4 kb of DNA and including the beta globin gene. 3. The evidence for the localization of the gene comes from three pieces of data. (a) Chromosome 11 is labelled to double the extent expected if the grains were randomly distributed, (b) the extra grains above background are clustered on the short arm of 11 close to the centromere, and (c) the absolute number of grains observed is very close to that predicted for a probe of that length by comparison with ribosomal genes. The localization is in agreement with that obtained by other methods. 4. This method could be extended to any gene for which a genomic clone containing at least 5 kb of single copy DNA is available.

Problems of families caring for Alzheimer patients: use of a support group

An eight-week support group program was conducted for 15 members of the families of Alzheimer patients still living at home. It became clear that caring for an Alzheimer patient at home created tremendous practical, psychologic and social problems for family members. Frequently discussed problems included lack of support and information from physicians, poor understanding of the disease, depression, a trapped feeling, anger and fear about the patient's behavioral problems, isolation, and the caretaker's loss of self-identity. Group participation was especially beneficial for spouses who functioned as primary care providers. It increased their understanding of the disease, made them feel more supported and less isolated, and helped them resolve some of the feelings created by the illness. It also helped spouses to become more aware of their own needs and to regain some self-identity in relation to the patient. Such family support programs offer a way to strengthen the emotional well-being and treatment skills of the care-providing family and are an important aid to treatment in Alzheimer's disease.

Strategies in instructional materials development for African health professionals

An international program in health professions training has involved the development of a teaching materials library by teams of African faculty authors and U.S. instructional materials specialists. Communications difficulties and differences in culture and technology have made it necessary that the instructional designers develop new production and management strategies, in order to meet program objectives and to assure the quality of the teaching materials. These strategies would seem to have continuing applications to domestic as well as international instructional development programs.

Estrus synchronisation and fertility in gilts using a synthetic progestagen (Allyl Trenbolone) and inseminated with fresh stored or frozen semen

An orally active synthetic progestagen was administered at two dosage levels to synchronise estrus in gilts. Fertility following insemination with either fresh stored or frozen semen was determined by examining surgically recovered ova for cleavage, and numbers of spermatozoa attached to the zona pellucida, or enumeration of embryos in gilts slaughtered 30 days post insemination. There was no significant difference (P>0.05) between treated and control groups in the duration of estrus or in fertility as determined by cleavage of ova. A significantly (P<0.001) shorter interval to estrus and better synchronisation was obtained with both treatment groups than with the control group. The mean interval from the end of treatment to the onset of estrus for the untreated controls and the treated groups receiving 12.5 and 15 mg compound per day was 11.25 +/- 10.4 SD; 5.6 +/- 0.52 SD and 7.3 +/- 5.3 SD. Fresh semen yielded significantly (P<0.01) more cleaved ova than frozen semen.