HIV and dentistry. Part 7. The HIV positive dentist or student

What should a dentist or dental student do when he happens to be HIV-seropositive? Should he or she disclose the disease to the patients or, in case of a student, to the university? Does he has to give up his practice or perhaps not even open one? Apparently, the legal regulations differ in various parts of the world. In the Netherlands dentists are advised to take their own responsibility in this matter.     

Amalgam. XI. Glass-ionomer as a possible substitute of amalgam: longevity

The clinical use of glass-ionomer increases, also for restorative goals. The longevity of glass ionomer restorations is among others determined by premature contact with saliva and by acid erosion. The adherence to the dental hard tissues may be increased by acid pretreatment. The longevity data presented here indicate that glass ionomer restorations do not last as long as amalgam restorations. In the deciduous teeth the material seems to be a more acceptable substitute for amalgam. The same holds true for restorations which are not submitted to stress, such as class V.     

Daytime sleep in myotonic dystrophy is not caused by sleep apnoea.

Daytime sleepiness is common in myotonic dystrophy and might be attributed to disturbed nocturnal breathing. Seventeen out of 22 patients complained of excessive daytime sleepiness, resembling "idiopathic hypersomnolence". Sleep apnoea might have contributed to daytime sleepiness in only three of 17 patients. Treatment with the central stimulant methylphenidate produced sustained benefit in seven out of 11 patients tested. Daytime sleepiness in myotonic dystrophy is usually caused by dysfunction of central sleep regulation and not by disturbed nocturnal breathing.     

Percutaneous burrhole trephination of the skull: a study of 519 cases

We want to report on our experiences with the percutaneous trephination using a 2.35 mm round dental drill with serrated saws around it, a Rosenbohrer. It is a methodically similar activity as described by J. Zentner [11].From 1981 to 1992 519 patients were treated and 546 trephinations were performed.At the beginning this treatment was only used in connection with intracerebral bleedings and biopsies.In a considerable short time the indication could be extended to the subdural hematoma, tumor cyst, obstructive hydrocephalus as well as to the abscess and the subdural epyema.The rate of infection was 1.28% and the risk of bleeding 0.36%.In our opinion the advantages of this small electrical trephination are the easy handling, the universal use and mobility and the avoidable risk of anesthesia as well as the sterilisation at the same time and the stopping of blood, caused by the contact surface friction.     

Comparison of non-invasive approaches to red marrow dosimetry for radiolabelled monoclonal antibodies

Red marrow is usually the dose-limiting organ during radioimmunotherapy. Several non-invasive approaches to calculate the red marrow dose have been proposed. We compared four approaches to analyse the differences in calculated red marrow doses. The data were obtained from immunoscintigraphy of two antibodies with different red marrow kinetics [iodine-131-16.88 IgM and indium- 111-OV-TL-3 F(ab)₂]. The approaches are based on, respectively, homogeneously distributed activity in the body, a red marrow-blood activity concentration ratio of 0.3, scintigraphic quantification, and a combination of the second and third approaches. This fourth approach may be more adequate because of its independence from the chosen antibody. In addition, the influence of activity accumulation in liver, kidneys or cancellous bone on red marrow dose was studied. The calculated red marrow dose varied between 0.14 and 0.42 mGy/MBq for ¹¹¹ In-OV TL-3 and between 0.13 and 0.68 mGy/MBq for ¹³¹I-16-88. If the radiopharmaceutical shows high affinity for cancellous bone or another organ situated near the red marrow, the activity in these organs must be included in dose calculations. This study shows a large variation in calculated red marrow dose and selection of the definitive non-invasive approach awaits validation. Correspondence to: M.A.B.D. Plaizier     

Follow-up of patients with colorectal cancer. A meta-analysis.

OBJECTIVE: The authors sought to determine whether intensive follow-up improves 5-year survival rates in patients with colorectal cancer who were operated on for cure. SUMMARY BACKGROUND DATA: Intensive follow-up of patients with colorectal cancer is still controversial. The present uncertainty in regard to the value of intensive follow-up could be the result of the absence of prospective randomized studies comparing patients with and without follow-up. METHODS: Studies comparing two follow-up programs of different intensities were identified in the medical literature and were aggregated in a meta-analysis using the "random effects method." Seven nonrandomized studies describing 3283 patients were analyzed. RESULTS: Patients with intensive follow-up did have 9% better 5-year survival rates than did those with minimal or no follow-up, only when intensive follow-up included carcinoembryonic antigen (CEA) assays. In addition, more asymptomatic recurrences were detected and more recurrences were resected in patients with intensive follow-up. CONCLUSIONS: This meta-analysis indicated that intensive follow-up using CEA assays can identify treatable recurrences at a relatively early stage. Treatment of these recurrences appears to be associated with improved 5-year survival rates. However, not all intensive follow-up strategies will be equally effective. Follow-up may yield the best results if diagnostic tests are used only to detect those recurrences that can be operated on with curative intent and when follow-up is "individualized," according to patient characteristics.     

Incidental cholecystectomy during colorectal surgery.

OBJECTIVE: To assess the risks and benefits of incidental cholecystectomy in patients having colorectal surgery. SUMMARY BACKGROUND DATA: Cholelithiasis is found commonly during abdominal surgery. Previous studies used disparate methods to assess the risks and benefits of incidental cholecystectomy and have reached contradictory conclusions. METHODS: All patients in whom asymptomatic cholelithiasis was noted during colorectal surgery between January 1982 and December 1986 were studied. Operative morbidity and long-term outcome were assessed by chart review and questionnaire. RESULTS: Three hundred five patients were identified, of whom 195 (63.9%) had an incidental cholecystectomy and 110 (36.1%) did not. The two groups were similar in terms of age, sex, primary disease, and associated medical conditions, although fewer emergency procedures, abdominoperineal resections, and Hartmann's procedures were needed in the cholecystectomy group. The overall operative morbidity rate was the same in both groups. The long-term risk for developing small bowel obstruction was also similar. After a median follow-up of 6 years after hospital discharge, biliary pain or cholecystitis developed in 16 patients (14.6%) in the "no cholecystectomy" group, 12 of whom have had cholecystectomy. Two additional patients had cholecystectomy for acute postoperative cholecystitis while still in the hospital. Six more patients have had incidental cholecystectomy at subsequent laparotomies. The cumulative probability of needing cholecystectomy at 2 and 5 years after the initial colorectal operation was 12.1% and 21.6%, respectively. CONCLUSIONS: Incidental cholecystectomy was not associated with increased postoperative morbidity, whereas the long-term risk that previously asymptomatic gallstones would become symptomatic was substantial. Unless there are clear contraindications, patients with asymptomatic gallstones who have colorectal surgery should have concomitant cholecystectomy.     

Amino acid and carnitine supplementation in haemodialysed children

Plasma carnitine, amino acids and lipids levels were studied in ten uraemic children treated with haemodialysis and given amino acid supplementation with and without carnitine. As carnitine is synthesised from lysine and methionine and has a significant influence on lipid metabolism, the relationship between these was examined. Amino acid supplementation (0.25 g/kg body weight) was started with the intention of improving the plasma amino acid pattern in these children and increasing the concentration of lysine, which is the substrate for carnitine synthesis. Amino acids were administered i. v. during dialysis and carnitine (25 mg/kg body weight i. v.) was administered after dialysis three times a week. Concentrations of most essential amino acids were decreased in these patients. The first period of amino acid supplementation did not increase plasma levels of the essential amino acids, with the exception of tyrosine (P<0.01). After the second period of supplementation, methionine was increased (P<0.01), isoleucine was decreased (P<0.01), but tyrosine normalised and was significantly lower than after the first period (P<0.05). Thus overall amino acid supplementation did not improve amino acid levels; it was inconsistently associated with a further decrease in highdensity lipoprotein-cholesterol and an increase in total protein levels. Lysine concentrations after amino acid supplementation remained low. Paradoxically, before carnitine supplementation a positive correlation between free carnitine and triglycerides was observed. The plasma carnitine concentration, initially very low, was excessively high after carnitine supplementation. After carnitine administration no amelioration of any of the other biochemical indices was observed. Carnitine supplementation was associated with a significant reduction of total protein levels (P<0.01). In children with end-stage renal disease on haemodialysis, neither amino acid nor carnitine supplementation appear to result in significant improvements in plasma levels of essential amino acids or lipids.     

Effects of water-borne cadmium on the skin of the common carp (Cyprinus carpio)

The skin of carp, Cyprinus carpio, was studied at the ultrastructural level after exposure of the fish to low and high concentrations of cadmium in the water (22 and 560 g/L, respectively) for different periods. The effects of the low concentration of cadmium were similar to those of the high concentration, although they appeared later. The basal lamina and the skin surface became highly undulating. Chloride cells appeared between the pavement cells. Necrotic pavement cells were seen from the first day on, while apoptotic pavement cells appeared after several days. Filament cells contained many electron-transparent and electron-dense secretory vesicles. Mitotic cells were commonly seen, mainly in cells adjacent to club cells or close to the epidermal surface. Mucous cells differentiated close to the skin surface. They became elongated and synthesized highly electron-dense mucosomes. The epidermis became infiltrated by many leucocytes. As the experiment progressed, many leucocytes degenerated, and their remnants were found within macrophages and club cells. Fibroblasts displayed intense synthesis and, in fish from the low cadmium concentration, deposited a dense network of collagen fibers in the dermis. Melanosomes were located in the extensions of melanocytes. In these cells aggregation of melanosomes and apoptotic processes were common. Several of these changes were observed earlier under the impact of stressors other than cadmium. Some changes, such as the appearance of tumorlike bodies at the skin surface, the appearance of Merkel cells throughout the epidermis, and the coupling of leucocytes, may be specific for cadmium.     

Lay people's evaluations of health: are there variations between different subgroups?

STUDY OBJECTIVE--To elicit lay concepts of health and to see whether these are related to various sociodemographic factors, as has been suggested by previous smaller studies. DESIGN AND SETTING--A total of 196 people aged 18 and over were selected, as a representative sample of the general population, from the electoral registers of Walsall and Dudley in the West Midlands. Respondents were interviewed in their own homes in the autumn of 1989. MEASUREMENTS--Open ended and structured questions were used to elicit concepts of health. The three main stages consisted of an unprompted section in which respondents were asked to describe the features of good or poor health in themselves or others; a prompted section in which they were asked to rate 37 health statements using a series of categories from "very important" to "not at all important"; and a section in which they were asked to indicate which of six groups of statements, each representing a particular concept of health, best represented their own notions of health. RESULTS--Health was seen as multidimensional. Irrespective of whether respondents addressed health in self or health in others, or good or poor health, the biomedical dimension remained an important one. The manner by which concepts of health are elicited may provide some explanation as to why so many and varied concepts are alleged to be held by different subgroups of the population (notably different social classes). CONCLUSIONS--The differences found in this study between models of health employed by different subgroups of the general population have not been as great as has previously been suggested in the published reports. This is encouraging for those using existing health status measurements.