Teaching biomedical applications to secondary students.

Certain aspects of biomedical engineering applications lend themselves well to experimentation that can be done by high school students. This paper describes two experiments done during a six-week summer internship program in which two high school students used electrodes, circuit boards, and computers to mimic a sophisticated heart monitor and also to control a robotic car. Our experience suggests that simple illustrations of complex instrumentation can be effective in introducing adolescents to the biomedical engineering field.

New X-linked syndrome with severe mental retardation, severely impaired vision, severe hearing defect, epileptic seizures, spasticity, restricted joint mobility, and early death.

A family with an X-linked mental retardation syndrome involving seven children in two generations is reported. The syndrome includes microcephaly, severe mental retardation, optic atrophy with severely impaired vision or blindness, a severe hearing defect, spasticity, epileptic seizures, restricted movement of the large joints, and death in infancy or early childhood. We conclude that this is a distinct, previously unrecognized X-linked mental retardation syndrome.

Thrombocytopenic purpura and coeliac disease.

In a child with immune thrombocytopenic purpura (ITP) the findings of circulating reticulin antibodies and IgA and IgG gliadin antibodies suggested the diagnosis of coeliac disease. This was verified by small intestinal biopsy. In spite of a gluten-free diet the thrombocytopenia persisted. The association of ITP and coeliac disease was previously described in adults but to our knowledge this is the first report of the coexistence of ITP and coeliac disease in a child.

Antenatal prophylaxis of Rh immunization with 250 micrograms anti-D immunoglobulin.

Anti-D immunoglobulin (250 micrograms) was given i.m. to 830 Rh-negative primigravidae and multigravidae round the 32nd to 34th week of gestation. The multigravidae had previously been treated with anti-D immunoglobulin post partum or after abortion and had been followed up serologically after 8 months. Five hundred and twenty-nine of the women delivered Rh-positive infants and received another injection of anti-D immunoglobulin (250 micrograms) within 72 hours of delivery. At the serological follow-up 8 months after delivery 2 women (0.4%) had weak anti-D antibodies by the papain technique. No anti-D could be detected in these 2 women 14 and 20 months, respectively, after delivery. In a previously performed postnatal clinical study with 250 micrograms anti-D immunoglobulin the failure rate was 1.6% (10 out of 645 women). Thus, antenatal prophylaxis significantly (p less than 0.05) reduced the incidence of Rh immunization. The haemoglobin and bilirubin levels in cord blood and capillary blood did not differ in the Rh-positive and Rh-negative infants. Three primiparae (0.2%) had anti-D antibodies at the time of the antenatal injection before delivery. Thus, the antenatal regimen of gestation did not give full protection from Rh immunization. It is suggested that an antenatal injection at the 28th week of gestation would have been more effective, as Rh sensitization during pregnancy has been reported to be more frequent from the 29th week of pregnancy. Since the introduction of postnatal anti-D prophylaxis the Rh immunization occurring during pregnancy accounts for most of the observed failures (2, 4, 5, 14, 20). The efficacy and safety of antenatal injection of anti-D immunoglobulin has therefore been investigated (5, 6, 7). At the Växjö Hospital in Sweden, where the incidence of anti-D antibodies was 1.6% (15), 250 micrograms of anti-D immunoglobulin were given at about 32-34 weeks of gestation from March, 1973, to December, 1977. The results are presented here.

Transfer factor in the treatment of chronic mucocutaneous candidiasis: a controlled study.

A controlled cross-over study with transfer factor was carried out on 7 patients suffering from chronic mucocutaneous candidiasis. Only one patient showed clinical improvement, which started during a period of pretreatment with 5-fluorocytosine given orally 14 days before the patient entered this trial. No conversion to a positive skin test with Candida antigen or PPD was demonstrated following TF in the 6 patients who were anergic to either of these antigens. Variations in the cell-mediated immune response as revealed by lymphocyte transformation were observed in most patients, especially when studied over a long period of time. However, no pronounced efficacy of TF vis-à-vis placebo in normalizing the cell-mediated immune response could be demonstrated in the 5 patients who completed the clinical trial. Systemic side effects were not observed.

Neurovisceral storage disorder simulating Niemann-Pick disease. A new form of oligosaccharidosis?

Two sisters are described with demonstrable splenomegaly already from infancy and, after the age of 2--4 years, signs of slowly progressive encephalophy, vacuolated lymphocytes in the peripheral blood, and peculiar foam cells in the bone marrow aspirates. The died at 7 3/4 and 6 1/2 years. Widely spread in the brain, the nerve cell bodies were found to show extensive ballooning. It was most striking in the brain stem and spinal cord, while cerebellar structures were remarkably well preserved. The cytoplasm of the ballooned nerve cells was filled with finely granular storage material stainable as a readily soluble glycolipid. The spleen, liver and intestinal wall contained numerous foamy PAS-positive macrophages. Chemical assays showed a ten-fold increase of lactosylceramide and a modest one of minor gangliosides brain cortex. No accumulation sphingomyelin could be revealed, and the sphingomyelinase activity was found to be normal. The ganglioside GM1 beta-galactosidase activity of leucocytes was reduced to 20--25% of normal, which indicated a disturbance of the glycosaminoglycan metabolism. The tissue content of glycosaminoglycans was, however, normal, but an accumulation of lactose was demonstrated in the spleen. It is postulated that the primary enzymic defect is a disturbance of a lysosomal beta-galactosidase with a substrate specificity for lactose and other oligosaccharides with a terminal beta-galactosidic linkage.

Intravenous gamma-globulin infusions in patients with hypo-gamma-globulinemia: prevention of adverse reactions with corticosteroids.

A gamma-globulin preparation for intravenous use was given to 11 patients with antibody deficiency syndromes. Most of them had reacted earlier to intramuscular injections of normal gamma-globulin. The gamma-globulin employed produced adverse reactions, often quite severe in 8 of 9 intravenous infusions in three patients. After premedication with hydrocortisone, side effects appeared on 18 of 48 occasions in 10 patients, but only twice were they so severe that the infusions had to be interrupted. Thus, it seems that hydrocortisone diminishes the risk of side effects. The intravenously administered gamma-globulin seemed to be just as effective as the preparations for intramuscular use, and no severe infections appeared during the period of observation. There was no indication that the single hydrocortisone injections, usually 200 mg, increased the risk of contracting infections, but still such medication should be used with great caution in antibody-deficient patients.

Hepatitis B immune globulin in prevention of hepatitis B among hospital staff members.

In a double-blind trial of hospital staff members at risk of contracting hepatitis B, 110 subjects received hepatitis B immune globulin or immune serum globulin prophylactically. An additional 125 individuals working in the same locations were unwilling to participate in the trial and received no prophylaxis. During the study period of 28 months, 13 cases of clinical hepatitis B occurred in the untreated group, whereas only three cases occurred among the subjects who received prophylaxis.

Hepatitis B immune serum globulin and standard gamma globulin in prevention of hepatitis B infection among hospital staff: a preliminary report.

In May 1973 a controlled double-blind clinical trail with prophylactic injects of hepatitis B immune serum globulin (antibody titer by passive hemagglutination 1:355,000) and standard gamma globulin (1:100) was started in Sahlgren's Hospital, Göteborg, Sweden. The annual attack rate of clinical hepatitis B in the three departments studied had been 5 to 8 per cent during recent years. A total of 118 members of the hospital staff were prophylactically treated while 125 staff members were unwilling to participate and received no prophylactic treatment. During the first 20 months of study nine cases of clinical hepatitis B with jaundice occurred within the untreated group (7.2 per cent) while three cases (2.5 per cent) were observed in prophylactically treated individuals. After decoding it was found that 60 individuals had received specific hepatitis B immune serum globulin while 58 had received standard gamma globulin. Two of the three clinical cases of hepatitis B occurred within the standard gamma globulin group. Both groups included two individuals with transient antigenemia only and the standard gamma globulin group also included four individuals with antibody seroconversion.

Fibrin-stabilizing factor inhibitors. 12. 5-Dibenzylaminopentylamine and related compounds, a new type of FSF inhibitors.

A series of omegadibenzylaminoalkylamines and related compounds have been prepared and tested as inhibitors of fibrin cross-linking. This structural type was chosen in an attempt to develop noncompetitive inhibitors of fibrinoligase. By the combination of the dibenzylamino moiety at one end and the primary amino group at the other end of a polymethylene chain, the same compound could function both as a pseudo donor substrate and as a noncompetitive alkylating inhibitor. Some of the compounds, notably 74-79, are among the most active fibrinoligase inhibitors described. However, the data indicate that the compounds probably function only as pseudo donor inhibitors.

Hepatitis B immune serum globulin in prevention of hepatitis B among hospital personnel. Preliminary report from a controlled trial.

At Sahlgren Hospital, Göteborg, hepatitis B has been a serious problem for several years among the personnel in the hemodialysis and renal transplantation wards as well as in the chemical laboratories. For this reason a randomized controlled clinical study with conventional gammaglobulin and hepatitis B immune globulin was started in May 1973. The titer of anitbodies against HBsAg by passive hemagglutination was 1:100 and approximately 1:350,000, respectively. Newly employed staff without a history of jaundice and without demonstratable HBsAg (RIA) or HBsAb (RIP) in serum were enrolled in the trial. Assignment of the two preparations was performed by random numbers and the ampoules were labelled only with the serial number of the participant. Three cc of either preparation was administered i.m. within seven days after admission and was repeated three months later. After that no further injections were given. Each participating employee was followed up with liver function tests, IEOP, RIA and RIP tests for at least six months after the last injection. Preliminary results from this double-blind study, which is still going on, are presented.