Social support in the context of caregiving: husbands' provision of support to wives involved in parent care.

The purpose of this study was to identify ways in which social support is related to the caregiving stress and well-being experienced by adult daughter caregivers. The study focused on a specific source of support, caregivers' husbands, and included reports from 126 caregivers and their husbands. Main and buffering effects of four types of support (emotional and instrumental support provided to the caregiver and to her parent) were tested, and caregiver's level of optimism was controlled. Results were similar for caregivers' and husbands' accounts of support. Buffering effects were found only for physical health, whereas effects opposite those predicted by the buffering hypothesis were detected for positive affect. A main effect was found in nearly all analyses of marital satisfaction. No main or buffering effects of support were detected for depression. Findings highlight the complexity of supportive exchanges by illustrating the simultaneous operation of different types of support and their distinctive impact on the caregiving stress and well-being relationship.

Effect of hexylene glycol-altered microtubule distributions on cytokinesis and polar lobe formation in fertilized eggs of Ilyanassa obsoleta.

Some effects of gravity on early morphogenesis are correlated with microtubule locations within cells. During first cleavage in Ilyanassa obsoleta embryos, a transitory polar lobe constriction forms and then relaxes, allowing the polar lobe to merge with one daughter cell. If the polar lobe is equally divided or removed, morphogenesis is severely disrupted. To examine microtuble locations during early Ilyanassa development, eggs were fixed and stained for polymerized alpha-tubulin during first cleavage. The mitotic apparatus assembles at the animal pole. The cleavage furrow forms between the asters, constricting to a stabilized intercellular bridge encircling midbody-bound microtubules, whereas the polar lobe constriction forms below and parallel to the spindle, constricting to a transitory intercellular bridge encircling no detectable microtubules. At metaphase an alpha-tubulin epitope is distributed throughout the spindle, whereas a beta-tubulin epitope is present predominantly in the asters. Incubation in hexylene glycol, a drug that increases microtubule polymerization, during mitosis causes the polar lobe constriction to tighten around polymerized alpha-tubulin and remain stably constricted. If hexylene glycol is removed, alpha-tubulin staining disappears from the polar lobe constriction, which relaxes, whereas microtubules remain in the cleavage furrow, which remains constricted. These observations suggest that asymmetric distribution of microtubules affects early Ilyanassa cleavage patterns, and that continued presence of microtubules extending through an intercellular bridge is important for stabilization of the bridge constriction prior to completion of cytokinesis. These data provide the basis for further analysis of the role of microtubules in possible microgravity disruptions of Ilyanassa development.

Effects of silver ions (Ag+) on contractile ring function and microtubule dynamics during first cleavage in Ilyanassa obsoleta.

The terminal phase of cell division involves tight constriction of the cleavage furrow contractile ring, stabilization/elongation of the intercellular bridge, and final separation of the daughter cells. At first cleavage, the fertilized eggs of the mollusk, Ilyanassa obsoleta, form two contractile rings at right angles to each other in the same cytoplasm that constrict to tight necks and partition the egg into a trefoil shape. The cleavage furrow contractile ring (CF) normally constricts around many midbody microtubules (MTs) and results in cleavage; the polar lobe constriction contractile ring (PLC) normally constricts around very few MTs and subsequently relaxes without cleavage. In the presence of Ag+ ions, the PLC 1) begins MT-dependent rapid constriction sooner than controls, 2) encircles more MTs than control egg PLCs, 3) elongates much more than control PLCs, and 4) remains tightly constricted and effectively cleaves the polar lobe from the egg. If Ag(+)-incubated eggs are returned to normal seawater at trefoil, tubulin fluorescence disappears from the PLC neck and the neck relaxes. If nocodazole, a drug that depolymerizes MTs, is added to Ag(+)-incubated eggs during early PLC constriction, the PLC is not stabilized and eventually relaxes. However, if nocodazole is added to Ag(+)-incubated eggs at trefoil, tubulin fluorescence disappears from the PLC neck but the neck remains constricted. These results suggest that Ag+ accelerates and gradually stabilizes the PLC constriction by a mechanism that is initially MT-dependent, but that progressively becomes MT-independent.

Preliminary observations on the effects of vector-averaged gravity on the embryonic and larval development of the gastropod mollusk, Ilyanassa obsoleta Stimpson.

Fertilized eggs of Ilyanassa obsoleta Stimpson were collected immediately after their deposition in egg capsules. Unopened egg capsules then were affixed to glass slides, and incubated either statically (controls) or on a clinostat (experimentals). After incubation for 9-14 days, hatching occurred sooner and in a higher percentage of clinostated capsules than in controls. Embryos that hatched while undergoing clinostat incubation were abnormal in morphology, whereas other embryos present in non-hatched capsules in the same tubes appeared normal, as did embryos in the control tubes. Although the results are compatible with a conclusion that vector-averaged gravity in the experimental tubes caused the altered development, some other aspects of how the incubations were done may have contributed to the differences between the control and experimental results.

Preliminary observations on the effects of vector-averaged gravity on the embryonic and larval development of the gastropod mollusk, Ilyanassa obsoleta Stimpson.

Fertilized eggs of Ilyanassa obsoleta Stimpson were collected immediately after their deposition in egg capsules. Unopened egg capsules then were affixed to glass slides, and incubated either statically (controls) or on a clinostat (experimentals). After incubation for 9-14 days, hatching occurred sooner and in a higher percentage of clinostated capsules than in controls. Embryos that hatched while undergoing clinostat incubation were abnormal in morphology, whereas other embryos present in non-hatched capsules in the same tubes appeared normal, as did embryos in the control tubes. Although the results are compatible with a conclusion that vector-averaged gravity in the experimental tubes caused the altered development, some other aspects of how the incubations were done may have contributed to the differences between the control and experimental results.

A survey of the removable prosthodontic clinical experience of dental students.

A survey was sent to every dental school in the contiguous United States and Puerto Rico to solicit answers to 15 questions concerning various aspects of the prosthodontic education of the dental student. It was found that student clinical experiences differed significantly among the regions in terms of the total number of prosthodontic patients treated per student. Fees also differed significantly among the regions. No comment was made on the possible effects of denturism on either the type of patient or the number of removable prosthodontic patients available for treatment by dental students. Concerning the difficulty in securing the various types of patients, all categories were mentioned as being somewhat in short supply, although the greatest shortage was complete denture patients. There was no universally recognized solution to the shortage of patients, although lowering of fees and substitution of requirements were mentioned most frequently. Pertaining to the presence or absence of a strict requirement system, the vast majority of schools reported use of at least some type of requirement system, though not necessarily a strict one.

The relationship between the metacarpal index and the rate of mandibular ridge resorption.

This study tried to determine whether a relationship exists between the degree of alveolar resorption of the edentulous mandible and the degree of osteoporosis, as expressed by the metacarpal index. Eighty patients were examined. Each had a radiograph of the left hand to show the second metacarpal, and a standard pan-oral radiograph. A morphological measurement of the metacarpal bone, which is a good indication of the mineral content of the skeleton, was made on each hand radiograph. Alveolar resorption was estimated on the pan-oral radiograph by taking the original height of the alveolar process as being three times the distance from the inferior border of the madible to the inferior edge of the mental foramen. The regression analysis revealed no relationship between osteoporosis, as measured by the metacarpal index, and the amount of alveolar bone resorption.

A survey of accredited dental technology education programs in the United States.

A study was made of current educational methods and prosthetic technology used in the accredited dental technology education programs in the United States. Some of the results have been compared with the findings of a similar study in Britain and several differences have been noted. The results of this study and of the British one refer to accredited educational programs and do not necessarily reflect the procedures used in dental practice or in commercial dental laboratories.

Role of the dental technician in professional education.

This survey has documented the current role of dental technicians in dental schools in the United States. This role is still rather minor, but it is significant. Some suggestions for improving the situation have been made. A further survey of this kind should be made again in 3-5 years, at which time a comparison with this survey may reveal a developing pattern and some better clues to the future.