Atraumatic restorative treatment and glass-ionomer sealants in a school oral health programme in Zimbabwe: evaluation after 1 year

An oral health care programme in secondary schools using the atraumatic restorative treatment (ART) technique for dental caries was started in 1993. Glass-ionomer was used as the restorative and sealant material. Sealants were placed using the "press finger' technique. Results after 1 year revealed a survival percentage for one-surface ART restorations of 93.4 whilst the complete and partial retention percentages for sealants were 60.3 and 13.4, respectively. No caries was observed in teeth restored using ART, and only 0.8% of surfaces diagnosed as having early enamel lesions at the start of the programme and sealed consequently had progressed into active dentinal lesions after 1 year. The sealant retention percentage and the survival percentage of ART restorations were influenced by an operator effect. The majority of restorations were carried out without administering local anaesthesia. The mean treatment time for one-surface ART restorations was 22.1 min (range per operator of 19.8-23.6 min), whilst the mean time for placing sealants was 9.4 min (range per operator of 8.2-10.8 min). Post-operative sensitivity was reported for 6% of the teeth restored. 95% of the students were satisfied with ART as a treatment modality. It is concluded that ART may in part be the answer to the unavailability of restorative care for many population groups globally.     

Liver transplantation in Western Australia: improved services to an isolated population

OBJECTIVE: To assess performance of the Western Australian Liver Transplantation Service in the light of debate about whether small transplant centres can produce optimal outcomes. DESIGN: Review of patient data collected prospectively and confirmed by retrospective casenote review. SUBJECTS: All patients referred to the Western Australian Liver Transplantation Assessment Panel. Those who underwent transplantation at the Western Australian Liver Transplantation Service (to June 1996) were compared with those referred to other transplant centres before the elective service was established in July 1994. OUTCOME MEASURES: Numbers of referrals and transplants; characteristics of the transplantation procedure; and patient outcomes. RESULTS: Annual referrals for liver transplant in Western Australia (WA) increased from 12 (1985-1993) to 41 (July 1994-June 1996), with five deaths on the "activated" list before July 1994, but none after. To June 1996, 30 patients had received 31 transplants by the Western Australian Liver Transplantation Service (two emergency transplants in 1992 and 1993, respectively, and 28 elective transplants and one retransplant after June 1994), with median operation time of 5.5 hours (range, 3-10.5), median red cell transfusion of 4 units (range, 0-55) and median hospital stay of 24 days (range, 12-128). There was no severe primary graft dysfunction. Major complications included hepatic artery thrombosis or stenosis (5 patients, one requiring retransplant), biliary stricture not associated with hepatic artery pathology, bile leak and perihepatic abscess (4 each), and cytomegalovirus infection (3). Patient survival was 83% and graft survival 81% at a mean follow-up of 13 months, compared with 86% and 83%, respectively, at one year for WA patients who received transplants elsewhere before July 1994. CONCLUSIONS: Performance of the Western Australian Liver Transplantation Service compares favourably with national and international standards, and WA patients receiving liver transplants have increased dramatically since the service was established. This supports the viability of committed liver transplantation centres with only 10-15 patients a year and argues the need for nationally decentralised services.     

Freeze-fracture analysis of junctional complexes in the nephron of the garter snake, Thamnophis sirtalis

Zonulae occludentes are shown by freeze-fracture to be pleomorphic along the garter snake nephron. In the neck and proximal segments the occluding junctions are moderately complex with frequent discontinuities in their junctional fibrils. Junctional depth and complexity are maximal in the distal and collecting segments and discontinuities in fibrils are absent. Comparison of these results with similar observations on other tissues indicates that the zonulae occludentes in the neck and proximal segments are "intermediate" to "leaky" and that they may be "very light" in the distal and collecting segments. The findings suggest that in the garter snake nephron transepithelial flow of fluid may occur primarily by passive diffusion through the zonulae occludentes in the neck and proximal segments and by cell-mediated osmotic flow in the distal and collecting segments. Gap junctions occur only in the proximal tubule and areprobably involved in low resistance, intercellular movement of ions.     

Cortical neuronal function during ischemia. Effects of occlusion of one middle cerebral artery on single-unit activity in cats

To assess the effects of ischemia on neuronal function, the action potentials of 261 individual cortical neurons were recorded extracellulary and related to regional cerebral blood flow (CBF) measured by hydrogen clearance in 19 cats, seven of which had the left middle cerebral artery occluded during a recording. The onset of ischemia could be associated with transient increases of activity, including "seizure discharges," as well as cessation of activity. No activity was noted at CBF less than 0.18 ml/gm/min; at higher (but ischemic) values for CBF, abnormal patterns of activity frequently were recorded. One neuron recovered function after cessation in association with an increase of CBF, indicating a potential for the restoration of function of ischemic neurons by effective therapeutic measures.     

Influence of cold or hyperbaric helium-oxygen environments on mouse response to a respiratory viral infection

In investigating the stress effects of chilling (2-3 degrees C) and hypothermia (2-3 degrees C drop in body core temperature mediated by exposure to hyperbaric helium-oxygen atmosphere) on mouse resistance to "influenza," it was noted that these stresses adversely affected the course of pulmonary infection produced by aerosols of the NWS strain of influenza virus. Comparatively, respiratory LD50 values for control animals were about 25 virus plaque-forming units (PFU) with median mortality occurring on day 13. The LD50 values for mice chilled at 2-3 degrees C were about 15 PFU with median mortality on day 7, and for mice exposed to hyperbaric helium, about 12 PFU with median mortality on day 6. Cold or hyperbaric stress impaired interferon production. Impairment was observed at 24 h but not at 12 h post-challenge and persisted for several days until mice became moribund.     

Predictors of receiving aftercare 1, 3, and 18 months after a psychiatric emergency room visit

The resistances to sliding were studied as a function of five angulations (0 degrees, 3 degrees, 7 degrees, 11 degrees, and 13 degrees) using nine different couples made of stainless steel, single crystal sapphire, or polycrystalline alumina brackets against stainless steel, nickel titanium, or beta-titanium arch wires. After 22 mil brackets were mounted to fixtures and 21 x 25 mil arch wires were ligated with 10 mil stainless steel ligatures, the arch wires were slid through the brackets at 1 cm/minute in the dry state at 34 degrees C. The resistance to sliding was measured by one computer while five normal forces (nominally 0.2, 0.4, 0.6, 0.8, and 1.0 kg) were serially maintained by another computer. A second couple was prepared for each material combination with five normal forces that were each 0.1 kg less. Statistical fits of linear regressions were such that p <.001 for most tests. When couples were in the passive configuration at low angulations, all stainless steel wire-bracket couples once again had the least resistance to sliding. When the angulation exceeded about 3 degrees, however, the active configuration emerged and binding quickly dominated as the resistance to sliding increased over 100-fold. Under these conditions, the relative rankings among the materials transposed; couples of stainless steel had the most resistance to sliding, whereas, couples of the more compliant alloys, such as nickel titanium wire, had the least. Results suggested that the active configuration and subsequent binding emerged when no bracket clearance remained. This binding component increased in importance with angulation and was additive to the frictional component, that is, they followed the principle of superposition.     

Branching and/or collateral projections of spinal dorsal horn neurons

Branching and/or collateral projections of spinal dorsal horn neurons is a common phenomenon. Evidence is presented for the existence of STTm/STTl, STTc/STTi, STT/SMT, STT/SRT, SCT/DCPS, SST/DCPS, SCT/SST, STT/SHT, STeT/SHT, STeTs and other doubly or multiply projecting spinal neurons that have been anatomically and physiologically identified and named based on the locations of the cells of origin and their terminations in the brain. These newly discovered spinal projection neurons are characterized by a single cell body and branched axons and/or collaterals that project to two or more target areas in the brain. These novel populations of neurons seem to be a fuzzy set of spinal projection neurons that function as an intersection set of the corresponding single projection spinal neurons and to be at an intermediate stage phylogenetically. Identification strategies are discussed, and general concluding remarks are made in this review.     

Misleading leads. Thallium-201 uptake in rebound thymic hyperplasia

A review was made of the six cases of primary thyroid lymphoma diagnosed at our institution. An increase in the incidence was observed of this disease in the last two years, with no evidence of lower diagnosis of anaplastic thyroid carcinoma. The presenting symptom was compression in all cases. The interval time from symptoms to diagnosis ranged from 5 to 150 days. The centroblastic pattern was the most common histologic type, with a relevant role of MALT lymphoma in the last few years. Therapy included surgical exeresis in two cases on account of compressive symptoms and radiotherapy and/or chemotherapy was always preferred on account of the stage.