Effects of diflubenzuron on limb regeneration and molting in the fiddler crab, Uca pugilator

Fiddler crabs, Uca pugilator, were exposed to the insect growth regulator diflubenzuron (Dimilin^®) at 0.5, 5, and 50 μg/l after multiple autotomy of one chela and five walking legs. Regeneration of the first walking leg was monitored, and time to ecdysis, mortality, and morphology of the regenerated limbs observed. Continuous exposure to the chemical produced a dose-dependent retardation of regeneration. Animals molting in the higher concentrations exhibited significant mortality at ecdysis. Exposure to the pesticide for a single week produced similar but less severe effects. However, if crabs molted while in the pesticide, significant mortality was observed. The presence of sediment in the container with the crab moderated the effects of the pesticide, but did not eliminate them.

The regenerated limbs of the crabs that survived ecdysis were found to have lesions in the form of black areas in which the cuticle was improperly developed. These lesions were seen in crabs that had been in the pesticide for only one week (week 2 or week 3) as well as those that had had continuous exposure. They were also seen in crabs that regenerated in Dimilin with sediment. In addition, the number of setae on limbs was reduced compared to the number on limbs that had regenerated in clean sea water.     

Diagnosis of schizophrenia. Prediction of short-term outcome

Seven systems for the diagnosis of schizophrenia were compared in their ability to predict short-term outcome at follow-up: with each other, with selected specific symptoms, and with a simple additive composite symptom score. None of the systems nor the symptoms predicted strongly, but DSM-III and Schneiderian First Rank Symptoms and the composite score performed somewhat better than the other predictors.     

A proposed role for silicates and protein in the proliferative effects of saccharin on the male rat urothelium

High doses of sodium saccharin, a non-genotoxic chemical, lead to the formation of silicate-containing precipitate and microcrystals in urine of male rats. Differences in urinary protein, pH, sodium and other factors affect silicate-containing precipitate and microcrystal formation as well as the bladder effects of sodium saccharin. Total urinary silicon concentration (mostly soluble) in sodium saccharin-fed rats is similar to or lower than the concentration in control rats. Binding of saccharin to male rat urinary proteins was demonstrated by equilibrium-gel filtration. We propose that by binding to urinary proteins under appropriate conditions, saccharin produces a nidus for the formation of silicate-containing precipitate and crystals. These appear to be cytotoxic to the superficial bladder epithelium, with cell death resulting in regenerative hyperplasia. Factors that influence the formation of these silicate-containing materials might provide a rationale for sex, species, dose and dietary differences in response to sodium saccharin.     

Experimental extra-follicular histogenesis of follicular cysts

An animal model has been developed in which implantation cysts have been produced very close to developing teeth within the jaws of Vervet monkeys. Various deciduous teeth were extracted from both the maxilla and the mandible of 6 young Vervel monkeys. After 4 weeks, full thickness mucoperiosteal flaps were raised in these areas, up to 6 recipient sites were prepared in each monkey by drilling holes in the alveolar bone and small pieces of autogenous palatal mucosa were placed in these graft recipient sites. One monkey was killed after 5, 8, 22 and 25 weeks respectively and 2 after 52 weeks. Of the 33 implants placed, cyst formation occurred from 11 (33%). The distribution of the cysts was irregular in that 4 cysts were produced in each of 2 animals while no cysts were found in another 2 animals. The cysts produced were filled with keratin and lined partly by a thick keratinising epithelium and partly by a thin non-keratinising epithelium only a few cell layers thick. In one of the animals killed after 52 weeks, (he follicle of an erupting premolar tooth had collided with one of the cysts resulting in the cyst lining becoming incorporated into the follicle, partly replacing the follicular reduced enamel epithelium and forming now an integral part of the follicle. This observation supports the hypothesis that the follicular odontogenic keratocyst has an extra-follicular origin arising alter the eruption of a tooth into a pre-existing cyst cavity.     

A double blind, randomised, parallel group study to investigate the dose equivalence of Dysport® and Botox® in the treatment of cervical dystonia

OBJECTIVE—This study was designed toestablish whether a ratio of three units of Dysport^® isequivalent to one unit of Botox^® for the treatment ofcervical dystonia.
METHODS—Patients with predominantly rotationalcervical dystonia, and a minimum of four previous Botox treatments,were randomised to receive either the clinically indicated dose ofBotox or three times that dose in Dysport units. Study botulinum toxinwas administered in a double blind fashion, to one or more clinicallyindicated muscles, at one or more sites per muscle. Patients returnedfor assessment two, four, eight, and 12 weeks after treatment.
RESULTS—A total of 73 patients (Dysport, 38;Botox, 35) were entered. The Dysport group received a mean (SD) dose of477 (131) (range 240-720) Dysport units, and the Botox group receiveda mean (SD) dose of 152 (45) (range 70-240) Botox units. The mean(SEM) post-treatment Tsui scores for the Dysport group (4.8 (0.3)) andthe Botox group (5.0 (0.3)) were not statistically different (p=0.66).The study had 91% power to detect a clinically significant differenceof two points. Both groups showed substantial improvement in Tsui scoreby week 2 (mean (SD); Dysport, 46 (28)%; Botox, 37 (28)%), with apeak effect at week 4 (mean (SD); Dysport, 49 (29)%; Botox, 44 (28)%). A similar response profile was seen for other assessments ofefficacy. The duration of effect, assessed by time to retreatment, wasalso similar (mean (SD); Dysport, 83.9 (13.6) days; Botox, 80.7 (14.4)days; p=0.85). During the study 22 of 38 (58%) Dysport patientsreported 39 adverse events, and 24 of 35 (69%) Botox patients reported56 adverse events (p=0.35). A global assessment of efficacy and safetyconsidered that 29 of 38 (76%) Dysport patients and 23 of 35 (66%)Botox patients were treatment successes (p=0.32).
CONCLUSION—Patients with predominantly rotationalcervical dystonia treated with the clinically indicated dose of Botoxor three times that dose in Dysport units show similar improvements anddo not have significantly different safety profiles.

     

Nursing Management of the Infant With a Congenital Malignancy

Care of the newborn diagnosed with a congenital malignancy is a challenge for the neonatal intensive-care unit nurse. Malignancies found in infants differ from those found in older children. Nursing care of the neonate suspected or diagnosed with a congenital malignancy includes standard practices and problem identification as well as interventions unique to the patient with cancer. This article reviews the incidence, diagnosis, treatment, and nursing management of neoplasms diagnosed in neonates.     

Attitudes toward prevention of cardiovascular diseases among first-year students at eight American medical schools, 1983-1985

First-year medical students at eight U.S. medical schools were surveyed by written questionnaire in 1983-1985 to determine their attitudes toward cardiovascular diseases prevention at medical school entry. An overall response rate of 92% was achieved (2,654 questionnaires), and 97% of responders provided complete and analyzable survey data. Response rates at five of eight medical schools were 98-100%, and one school each had rates of 67, 84, or 90%. Differences in mean attitude responses from school to school were small, as were differences between men and women or between blacks and whites. This survey found that entering medical students have generally positive attitudes toward the effectiveness of preventive cardiology practice as well as toward the importance of research efforts in cardiovascular disease prevention. Students frequently indicated, however, that it is "extremely difficult" to change patients' unhealthful habits and that "physician encouragement" may not be sufficient to help patients achieve more healthful behaviors. These findings could be helpful in directing educational efforts for medical students. The data suggest that major emphasis should be placed on conveying facts regarding the physicians' efficacy in clinical preventive cardiology and on teaching the skills of preventive cardiology practice. Less emphasis appears to be necessary on encouraging positive attitudes about the importance of prevention since current students' attitudes appear to be already positive in this dimension.