Value of the multiple sleep latency test (MSLT) for the diagnosis of narcolepsy

Since its introduction, the multiple sleep latency test (MSLT) has played a major role in the diagnosis of narcolepsy. We assessed its diagnostic value in a series of 2,083 subjects of whom 170 (8.2%) were diagnosed with narcolepsy. The sensitivity of the combination of two or more sleep onset rapid eye movement (REM) periods (SOREMPs) with a mean sleep latency of < 5 minutes on an initial MSLT was 70% with a specificity of 97%, but 30% of all subjects with this combination of findings did not have narcolepsy. In some narcoleptics who had more than one MSLT, the proportion of naps with SOREMPs varied substantially from the initial MSLT to the follow-up test. The highest specificity (99.2%) and positive predictive value (PPV) (87%) for MSLT findings was obtained with the criteria of three or more SOREMPs combined with a mean sleep latency of < 5 minutes, but the sensitivity of this combination was only 46%. The combination of a SOREMP with a sleep latency < 10 minutes on polysomnography yielded a specificity (98.9%) and PPV (73%) almost equal to those obtained from combinations of MSLT findings, but the sensitivity was much lower. Our results suggest that the MSLT cannot be used in isolation to confirm or exclude narcolepsy, is indicated only in selected patients with excessive daytime sleepiness, and is most valuable when interpreted in conjunction with clinical findings.     

The diagnosis of allergy to rifampicin confirmed by skin test

Multiple exostoses syndrome is a rare autosomal dominant disorder that affects the enchondral skeleton during growth. The formation of numerous exostoses causes deformities of bones and joints. Degenerative malignant changes are described. A careful follow up during paediatric age is required. Three new cases in the same family are reported in this paper.     

Urinary antigen test as a screen for the diagnosis of beta-hemolytic streptococcal infections in newborn infants

OBJECTIVE: To differentiate between neonates with high and low risk of infections caused by group B beta-haemolytic streptococci (GBS), by using the urinary group B streptococcal antigen test. DESIGN: Retrospective. SETTING: Medical Centre Leeuwarden and Public Health Laboratory, Friesland, the Netherlands. METHODS: In a period of two years clinical, haematological and microbiological (including urinary group B streptococcal antigen detection) data were collected in newborns and their mothers who met one or more of the following criteria: a previous affected child, prolonged (> or = 12 hrs) rupture of membranes, fever in labour, unexpected preterm delivery, unexplained perinatal asphyxia. On the basis of surveillance cultures a colonization rate was made. GBS infection was 'suspected' in an unwell infant with a 'high' colonization rate; infection with GBS was 'proved' by a positive blood culture with GBS. RESULTS: 6 of 342 neonates had an infection with GBS. Risk of invasive infection increased with higher colonization rates. Sensitivity of the antigen test to detect colonization was low, sensitivity to detect neonatal infection was high (51 versus 100%). The negative predictive value of urinary antigen testing was 100%. Prolonged rupture of membranes (1.5% risk of infection) and maternal fever (5%) were the most important risk factors. CONCLUSION: In healthy neonates with risk factors but with a negative antigen detection test the risk of GBS infection is extremely low. In children with a risk factor a positive test result can indicate heavy colonization or infection. These children should be carefully observed and examined.     

Detection of cytomegalovirus (CMV) antigen for rapid diagnosis and monitoring of CMV diseases in AIDS

Ten to forty percent of the patients with acquired immunodeficiency syndrome (AIDS) develop sight- or life-threatening cytomegalovirus (CMV) infections. In some patients with AIDS, CMV is detected in the bronchoalveolar lavage fluid (BALF), urine, and other specimens, even when there are no symptoms of CMV disease. An indicator of active CMV infection is needed to facilitate the diagnosis of CMV disease in patients with AIDS or HIV infection and the evaluation of the efficacy of subsequent treatment. The present study was conducted during the period from 1993 to 1994. The subjects consisted of three patients with AIDS and a confirmed diagnosis of CMV disease (one case of retinitis, one case of gastrointestinal disease and one case of pneumonia), and five HIV-positive patients in whom CMV associated disease was ruled out. Those patients were monitored occasionally for the following parameters of active CMV infection and disease: expression of CMV antigen in the nucleus of polymorphonuclear leukocyte (CMV antigenemia), as it was determined with a monoclonal antibody against a lower matrix protein (p65); infectious CMV detected by shell vial method; CMV DNA detected by PCR; anti-CMV antibody titer; and histological findings. CMV p65 antigen was detected in the leukocytes of both the peripheral blood and BALF during the early phase of CMV disease in three out of three cases of the CMV disease group, and this antigen became negative in two out of two cases who responded to the therapy. All the five patients in the CMV-related-disease-negative group were negative for CMV antigenemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

The specificity of the CPK MB enzyme kinetic test for the diagnosis of acute myocardial infarction (author's transl)

The clinical usefullness of the CPK MB test (spectophotometric method) was evaluated on 139 patients admitted to a Cardiovascular Diseases Department with a diagnosis of suspected myocardial infarction. Serial determinations of serum MB isoenzyme creatine kinase, total creatine kinase, lacate dehydrogenase and hydrossibutirrate dehydrogenase were made at 1st, 2th, 3th, 4th, 5th, 6th, 7th day. Incidence of CPK MB false positive and false negative data were also determined and correlated with the electrocardiogram pattern and serum levels of other standard enzymes. Results indicate that the CPK MB kinetic test is highly specific (94%) and promptly available in the early diagnosis of acute myocardial infarction.     

A re-evaluation of the slide flocculation test for the diagnosis of schistosomiasis with adult worms as antigen

A large tumor of the right atrium was found to be only the precimal end of a bland thrombus of the inferior vena cava. Of special interest were certain echocardiographic findings, including persistent delay in closure of the tricuspid valve after successful removal of the thrombus.     

Immunogold localization of the 97-kD antigen of linear IgA bullous dermatosis (LABD) detected with patients'' sera

The classification of linear IgA bullous dermatosis in the group of subepidermal blistering diseases is still a matter of controversy. This situation is due partly to the considerable clinical heterogeneity of the disease but also results from the difficulties in characterization and localization of the specific basement membrane zone antigen(s) recognized by immunoglobulin (Ig)A antibodies. In the present study, we have combined the Western blot detection of circulating autoantibodies with an ultrastructural immunogold labeling of human skin antigens using the same patients' sera. Our results, obtained with a short series of sera showing exclusive IgA class reactivity with the epidermal portion of salt-split skin, indicate that the antibodies recognizing the 97-kD antigen on immunoblot bind to the hemidesmosomal plaques of basal keratinocytes and the adjacent lamina lucida. These homogeneous laboratory results remain in striking contrast to the heterogeneity of clinical pictures in the patients studied, suggesting a participation of complementary, possibly not humoral, phenomena in the pathogenesis of linear IgA bullous dermatosis.     

Homozygous protein C deficiency can be detected by prenatal diagnosis

Homozygous protein C deficiency (HPCD) with purpura fulminans is a rare condition with an estimated incidence of 1-2 per 400,000 births. About 20 case reports have appeared since the first one was published in 1983. HPCD provides an excellent illustration of the fundamental importance of the protein C anticoagulant pathway. This severe coagulopathy results in serious organ damage, often already in utero, and without treatment it is incompatible with life. The treatment options include fresh frozen plasma and protein C concentrate in the acute phase, followed by oral anticoagulant therapy. Over 160 different point mutations in the protein C gene have been identified in recent years, offering new possibilities for prenatal diagnosis. The article describes the case of a family who lost two children with congenital HPCD. But where the specific point mutation was identified thus enabling prenatal diagnosis to be performed in a subsequent pregnancy.     

Use of rat glomerular basement membrane (GBM) as antigen in indirect imunofluorescence test for detection of human anti-GBM antibodies (author's transl)

The purpose of this paper is to verify if we may use the rat glomerular basement membrane (GBM) as antigen, in indirect immunofluorescent test in isolated GBM (IIT-BGM) to detect human anti GBM antibodies. Rabbit anti-human GBM serum (A-H-GBMS) were obtained by rabbit's immunization with human GBM or rat GBM respectively. The content of anti-GBM antibodies in rabbit's sera was determined in IIT-GBM. The titer of the A-H-GBMS was 1/10 when determined in IIT-GBM performed in human GBM and only weakly positive in IIT-GBM performed in rat GBM. The titer of A-R-GBMS was 1/60 and 1/20 when determined respectively in rat GBM and in human GBM. All the reactions performed with sera absorbed with autologous GBM were negative; the absorption of sera with heterologous GBM reduced sera titer. In conclusion: a) rat and human GBM have common and different antigenic components; b) to detect human anti-GBM antibodies we must not employ rat GBM in IIT-GBM.     

The interaction of elderberry (Sambucus sieboldiana) bark lectin and sialyloligosaccharides as detected by 1H-NMR

The interaction of Japanese elderberry bark lectin (Sambucus sieboldiana agglutinin, SSA) with carbohydrate was investigated by 1H-NMR. When a low affinity ligand, methyl beta-D-galactoside (beta MeGal), was mixed with SSA, each proton signal of beta MeGal was broadened. The signal of H-4 was markedly broad, while those of H-1, OCH3, and H-2 of beta MeGal were rather sharp. The specific broadening of Gal H-4 was more evident when SSA was mixed with methyl-beta-D-lactoside (beta MeLac). Position-dependent signal broadening suggests that beta MeGal binds to SSA such that H-4 is closely involved in the contact region, but H-1, OCH3, and H-2 are far from this region. In the case of a high affinity ligand, Neu5Ac(alpha 2-6)Gal(beta 1-4)Glc(= N6L), ligand signals of the SSA-N6L mixture did not change at all. But when a small amount of N6L was added to the SSA-beta MeGal mixture, the broad signals of bound beta MeGal became dramatically sharp. This indicates that the added N6L molecules liberated the bound beta MeGal from SSA. On the other hand, the sialyllactose with the alpha(2-3)-linkage(= N3L) could not substitute for bound beta MeGal because of its lower affinity. This demonstrates that the competitive binding experiment between two ligands is a useful technique to detect the interaction of lectins with high affinity ligands which could not be observed directly by NMR signal broadening and/or chemical shift change.     

The sheep OL lymphocyte antigen system: 11 factors detected by microcytotoxicity assays in a prealp flock

By means of microcytotoxicity techniques and using 9 immune allosera, 11 lymphocyte factors were determined in Prealpe sheep, 10 factors, transmitted by haplotypes, depended genetically on 2 linked locus: OL-A and OL-B. From a sample of 130 haplotypes, 36 OL-A alleles were demonstrated by 6 combinations of 1 to 2 factors and 80 OL-B alleles by 32 combinations of 1 to 5 factors. Genic frequencies were varied and low: inferior to 0,01 for half of the combinations they only once exceeded 0,1. The overall frequency of marked genes was estimated to 0,27 for OL-A and 0,61 for OL-B. The genetic transmission of the 11th factor (frequency: 0,05) depended on a 3rd OL-C locus of the same system.     

An antigen for the diagnosis of M. pneumoniae infections by passive hemagglutination

The authors establish the optimal conditions (protein concentration, temperature) for the coupling of purified mycoplasma antigen to sheep red blood cells, in order to obtain an antigenic complex stable for at least 1 year. This comples allows specific determination by passive hemagglutination--a simple and rapid technique--of anti-mycoplasma antibodies in the sera of men or animals suspected of mycoplasma infections. Under the stated experimental conditions, antibody titers equal to or higher than 1/128 indicate an infection with M. pneumoniae.     

Potential for oxytetracycline administration by three routes to cause milk residues in lactating cows, as detected by radioimmunoassay (Charm II) and high-performance liquid chromatography test methods

Milk antimicrobial residues are a serious concern for the dairy industry. Residues of the tetracycline family of antimicrobials have been reported in market milk by investigators, using radioimmunoassay and microbial receptor technology (hereafter referred to as the Charm II test). In response to these reports, an investigation was conducted to determine the potential of 3 extra-label routes of oxytetracycline (OTC) administration to cause milk residues above the Food and Drug Administration safe value of 30 parts per billion (ppb). Lactating Holstein cows were administered OTC once by use of 1 of 3 routes: IV at 16.5 mg/kg of body weight (n = 6); IM at 11 mg/kg (n = 6); and intrauterine (IU) at 2 g in 500 ml of saline solution/cow (n = 6). Duplicate milk samples were collected at the milking prior to drug administration and for the next 13 milkings at 12-hour intervals. Concentrations of OTC in milk samples were analyzed by use of the Charm II tes for tetracyclines (limit of OTC detection, approx 5 ppb) and were compared with concentrations determined by use of a high-performance liquid chromatography (HPLC) method (lower limit of OTC quantitation, approx 2 ppb). The potential for milk OTC residues above the Food and Drug Administration safe value of 30 ppb after treatment was considerably greater for the IV and IM routes, compared with the IU route.(ABSTRACT TRUNCATED AT 250 WORDS)