The use of dense alumina-alumina ceramic combination in total hip replacement

The purpose of this article was to review the laboratory and clinical performances since 1970 of a total hip prosthesis using alumina-alumina combination. The chemical and physical properties of dense alumina ceramic were studied in relation to biocompatibility, mechanical strength, and surface properties. Through the examination of 35 retrieved implants, it was found that the long-term success of alumina-alumina total hip replacement depends on both the ceramic microstructure (small grain size with uniform distribution, minimum porosity, absence of inclusions) and implant geometry (sphericity deviation +/- 1 micron, radius tolerance between components 7-10 microns). Alumina component wear and fractures have disappeared with the use of high-performance materials and severe manufacturing quality control. Examination of human biopsies from well-fixed prostheses showed that alumina particles deposits increase with time with only a low-grade macrophagic reaction. When loosening occurred, an inflammatory reaction appeared; this reaction was less striking than with loose metal-polyethylene prostheses, however. The long-term behavior of cementless alumina cup fixation depends upon initial positioning and stability; survivorship analysis of the cemented ceramic cups showed an 88% survival probability after 8 years with a 1.6% average annual probability of revision. The percentage of surviving was 100% after 8 years in patients who were less than 50 years old. Aseptic loosenings occurring at the cup-cement interface were assumed to be related to stress protection secondary to the high rigidity of the ceramic leading to a weakening of the spongious bone supporting the cement mantle. Good bone stock quality as well as high-quality ceramic appear to be the prerequisites for durable fixation of alumina sockets.

Cognitive development and reading achievement in pervasive-add, situational-add and control children

Studies on hyperactivity have shown the importance of distinguishing hyperactive children according to the pervasiveness of their symptoms. To verify the meaningfulness of this distinction in Attention Deficit Disorders, an epidemiological study was undertaken. Sixteen pervasive-ADD, nine situational-ADD and 28 non-ADD children selected from a general population were compared using different measures. The results show that pervasive-ADD differ from non-ADD children on verbal IQ and reading difficulties and support the distinction of ADD according to the pervasiveness of the symptoms.

Temperament and intellectual development: a longitudinal study from infancy to four years

Using three temperamentally different subgroups from a large birth cohort, the authors undertook a longitudinal study of the association between temperament measured in children at 4 and 8 months and IQ assessed at 4.7 years. The data suggested a strong effect of extreme temperament traits on IQ development in middle and upper socioeconomic classes and in families with superior functioning in terms of communication. The temperamentally difficult group unexpectedly displayed higher IQs, and the well-replicated effect of socioeconomic status on IQ development was observed mainly in this group. These data support the hypothesis that difficult infants activate special family resources, which stimulates intellectual development over the years.

A hand-held decision-aid system designed for rural health workers

A great part of the world's population is cared for by rural health workers who are also collecting data for epidemiological studies. These workers have a low level of medical training and are working in a poor technical environment. At the request of an international humanitarian and medical organization (Médecins Sans Frontières), we have developed an integrated (hardware and software) system, TROPICAID, based on a hand-held computer and designed to increase rural health workers' efficiency. The software is easy to use and enables users to get information from an internal data base on 60 drugs. The decision-making module analyzes the patient's parameters (460 different symptoms are recognized) and indicates possible diagnoses (the system knows 210) and relevant treatments. In addition, the system facilitates the collection of medical data for elementary statistical analysis. The computer, which is lightweight (1.5 kg) and compact, runs on battery power for up to a week in normal use. The program which is written in Pascal and data are stored in high-capacity EPROMs. An early trial in Chad with Médecins sans Frontières has shown the value of such a project as well as a few weaknesses to be overcome.

Value of difficult temperament among 7-year-olds in the general population for predicting psychiatric diagnosis at age 12

The authors assessed the predictive value of "difficult" temperament, as defined in the New York Longitudinal Study, in 12-year-old children from the general population of Quebec City whose temperaments had been determined to be difficult or easy at age 7. The difficult and easy temperament groups were balanced for age, sex, and socioeconomic status. The authors used many convergent measuring devices and were blind to the temperament scores of the children at age 7. Temperamentally difficult children had more clinical disorders at age 12 that qualified for a DSM-III diagnosis. An association with family dysfunction in terms of behavior control seemed to increase this risk: there was a lower rate of clinical disorders among children in superior functioning families than among those in dysfunctional families.

Follow-up of a randomized trial for oat cell carcinoma evaluating the efficacy of peripheral intravenous nutrition (PIVN) as adjunct treatment

A randomized trial was initiated to compare the effects of peripheral i.v. nutrition (PIVN)-associated chemotherapy (adriamycin, vincristine, VP-16-213, and cyclophosphamide) versus a chemotherapy control group in patients with oat cell lung carcinoma. Thirty-nine evaluable patients were randomized. The test group included 19 patients, whereas 20 were followed in the control group. PIVN was scheduled each day the patient underwent chemotherapy. Each patient received 1,550 kcal day which included 10% glucose, 20% lipids, and amino acids which may or may not have been mixed in the same infusion bottle. The results show ten PIVN patients presently in complete remission at the end of three courses of treatment, compared to nine over the same time period in the chemotherapy control group. Thirty-three percent of patients are still alive after 15 months after the beginning of treatment. There was no significant difference in either general health or side effects, frequency or duration of complete remission, or survival time. After 1 year of treatment, 8 of 19 PIVN patients are still in complete remission, compared to 7 of 20 patients in the control groups.

[Present means to prevent premature birth]

Although overall statistics do not show marked decrease in the percentage of infants with a birth weight under 2,500 g, therapeutical advances of the past few years would allow to conduct an action to prevent prematurity. Namely: beta-stimulating agents can control threatened premature delivery, provided the mothers-to-be, and this is essential, get alarmed without delay and seek prompt advice of their physician, screening and treatment of cervicovaginal infections during pregnancy can undoubtedly be efficient, provided the future mothers are regularly visited from the begining of their pregnancy. But such a prophylaxis necessarily requires, at the various stages of its practice, intelligent cooperation of the pregnant women themselves. Such a cooperation could perhaps be obtained through obstetrical psychoprophylactic interviews as a complement to antenatal consultations, the number of which is too small and the time spent on them too short within the organizational frame of community medicine.