Vibratory perception threshold in diabetic neuropathy.

A total of 263 diabetic patients and 129 normal controls were enrolled in a study of vibratory perception threshold (VPT) using an electromagnetic vibrometer at two sites, the dorsum of the metacarpal bone of the index finger (IF) and the dorsomedial aspect of the metatarsal bone of the great toe (GT). The results showed that the mean values of VPT for both IF and GT were significantly higher in diabetics than in normal subjects. In both control and diabetic groups, the VPT values at GT only were elevated with increasing age. Furthermore, the mean VPTs at both IF and GT were related to the duration of illness and the severity of diabetes mellitus in the patient group. Eighty cases of diabetes mellitus received nerve stimulation tests including motor and sensory nerve conduction velocities of the upper and lower limbs. The results from these cases demonstrated good correlation between VPT and motor conduction velocity (MCV), but not between VPT and sensory conduction velocity (SCV). There was a negative correlation between VPT at IF and median MCV (p less than 0.0005) in the upper limbs, as well as VPT at GT and tibial MCV (p less than 0.0005) in the lower limbs. For clinical applications, VPT values seemed to be more sensitive than MCV in detecting neuropathic change in diabetic patients. Hence, impairment of vibratory perception can be taken as a subtle clinical sign of diabetic neuropathy, and measurement of VPT can be used as an index of a patient's current subclinical state.

Motor-evoked potentials in diabetes mellitus.

By using magnetic stimulation of the motor cortex and in the cervical region, conduction time in the central motor pathway was measured in 35 patients with diabetes mellitus (DM) and in 41 control subjects. Motor-evoked potentials (MEPs) were recorded from the contralateral thenar muscles. Central conduction time (CCT) was obtained by subtracting the latency of the spinal MEP from that of the scalp MEP. To compare central and peripheral nerve functions, the motor nerve conduction velocity (MCV) of the median nerve was also tested in patients with DM. In the 35 cases of DM, the mean latency of the cortical MEPs showed a significant increase, compared with normal controls; the mean CCT was also significantly prolonged in the patient group. There was a good correlation between central motor abnormalities and the duration of DM, as well as with impairment of the peripheral nervous system. Latencies of greater than two standard deviations were defined as abnormal. The abnormal rate in patients with DM was 29% for latency of the cortical MEP, 20% for latency of the cervical MEP and 37% for the CCT. In addition, there was a 35% abnormal rate for distal latency of the median MCV and a 40% abnormal rate for the median MCV. These findings support the theory that the metabolic disturbance in DM affects both the central and peripheral nervous systems in man. MEP studies provide objective measurements of central motor pathways.

Cutaneous thermal thresholds in normal subjects and diabetic patients without symptoms of peripheral neuropathy.

An automated system operating on the Peltier principle and using a two-alternative forced-choice testing technique was applied to measure the heat and cold thermal thresholds (HT and CT) in 63 normal subjects and 68 diabetic patients who had no clinical symptoms of peripheral neuropathy. To compare large and small nerve fiber functions, 34 of the diabetic group were also tested for vibration perception threshold (VPT) and nerve conduction velocity (NCV). The testing algorithm of the devices selected for used, including reference temperature and number of turns, was investigated for assessment of variability and reliability. The age effect on thermal thresholds was found in the normal group (p less than 0.001). There was a significant difference between HT and CT in an individual (p less than 0.01). CT was greater than HT in 68% of the subjects. The diabetic group had significantly higher thermal thresholds than the normal group (HT, 0.30 +/- 0.32 degree C vs 0.10 +/- 0.05 degree C, p less than 0.005; CT, 0.39 +/- 0.43 degree C vs 0.15 +/- 0.09 degree C, p less than 0.005). Thermal thresholds greater than the linear regression estimate for age plus three standard errors of estimate were defined as abnormal. The abnormality rate in diabetics was 33.8% for HT and 22.1% for CT. Of the 34 patients, 91.1% had abnormal results in at least one of the three tests: 47.1% abnormal for HT or CT, 67.6% for VPT, and 26.4% for NCV. No correlation existed between the thermal threshold and VPT (p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Secondary prevention of ischemic stroke with low dose acetylsalicylic acid.

In order to evaluate the efficacy of low dose acetylsalicylic acid (ASA) for the secondary prevention of ischemic stroke, this cooperative multicenter clinical trial was conducted on a non-blind basis. Patients having a first transient ischemic attack (TIA), reversible ischemic neurological deficit (RIND) or completed ischemic stroke were eligible for this trial. A total of 590 patients including 47 cases of TIA, 23 cases of RIND and 520 cases of completed stroke entered this study. These patients were allocated by the time of admission to one of the following 5 trial regimens: (1) vasodilators having no known inhibitory effect on platelet function (control group), (2) dipyridamole (DP) 50 mg 3 times a day (DP group), (3) ASA 300 mg once a day (ASA 300 mg group), (4) ASA 300 mg once in combination with DP 50 mg 3 times a day (ASADP group), and (5) ASA 100 mg once a day (ASA1 group). No difference in effect between the control and DP groups was observed, nor between the ASA 300 mg and ASADP groups. Therefore, we combined the control and DP groups to make a non-ASA group, and joined the ASA 300 mg and ASADP groups to make an ASA3 group. The differences in the cumulative event-free rate appeared to be significant between the non-ASA group and the ASA3 group and also between the non-ASA group and the ASA1 group. But the frequency distribution of age, territory of stroke, diabetes mellitus, cardiac disease, hematological disease and hyperuricemia were significantly different among these 3 study groups. We thus included these covariates in the Cox's proportional hazard model to control their possible confounding effects.(ABSTRACT TRUNCATED AT 250 WORDS)

The relation between motor evoked potential and clinical motor status in stroke patients.

Forty-one stroke patients and 41 normal controls of matched age, sex and body height were studied by magnetic stimulation of the motor cortex and lower cervical area. The cortical and cervical motor evoked potentials (MEPs) were detected from the abductor pollicis brevis muscle. The amplitudes and latencies of cortical MEPs, central conduction time (CCT), and interside difference of bilateral CCT (DCCT) in stroke patients showed significant difference in comparison with normal controls. The degree of motor weakness was statistically correlated with the severity of cortical MEP findings, but not with the deep tendon reflex and Babinski sign. The abnormal rate of cortical MEP was higher in patients with hemorrhage than in those with infarction. Six out of 17 patients with hemorrhage had prolonged CCT or DCCT, but only 3 out of 24 patients with infarction had the same findings. The cortical MEP findings in putaminal hemorrhage were more severe than in thalamic hemorrhage. In instances of infarction involving total middle cerebral artery territory (cortical and subcortical areas), the cortical MEP was absent in all cases (4/4). It was concluded that cortical MEP findings in stroke patients examined by magnetic stimulation showed good correlation both with the lesion radiologically and the motor deficit clinically. This is an acceptable method for quantitative evaluation of motor system function in stroke.

Non-radioactive oligonucleotide probe for detection of clinical enterotoxigenic Escherichia coli isolates of bovine origin.

Oligonucleotides (32 or 34 mer) corresponding to enterotoxigenic Escherichia coli STIa (ST-P) toxin gene were tailed with Bio-11-dUTP using terminal deoxynucleotidyl transferase. Plasmids from clinical E. coli isolates were prepared by modified rapid alkaline lysis procedure and dot-spotted. Biotinylated oligonucleotide probes were hybridized to detect the STIa toxin gene. The results were in agreement with that obtained by radioactive oligonucleotide probes. Of 135 clinical isolates (sampled from 6 different regions of France), only 7 (5.2%) were found to be STIa+. These 7 isolates were the only ones to be found positive for the K99 adhesive pili antigen. Both the probes were specific to the STIa toxin gene and failed to detect the closely related STIb (ST-H) toxin gene. Possibilities of their wide usage in clinical labs are discussed.

Nonradioactive labeling of synthetic oligonucleotide probes with terminal deoxynucleotidyl transferase.

Synthetic oligonucleotides were tailed at the 3' end using terminal deoxynucleotidyl transferase. Nucleotide triphosphates with free primary amines at the end of side chains were compared for their tailing efficiency and/or detection sensitivity, using biotin-11-dUTP as a reference. Free primary amines were tagged with activated biotin or fluorescein isothiocyanate. The probes were then detected with either streptavidin-alkaline phosphatase complex or anti-fluorescein antibodies and alkaline phosphatase-conjugated secondary antibodies. Tailing conditions were optimized and the probes were tested for detection of Escherichia coli ST1a enterotoxin DNA and rotavirus RNA.

Quantitative variations of red-cell cytochrome b5 reductase (NADH-methemoglobin-reductase) in the Algerian population: evidence for defective alleles.

A striking proportion of Algerian subjects was reported among patients with congenital recessive methemoglobinemia due to cytochrome b5 reductase deficiency (Kaplan et al. 1979). A population survey was carried out in red blood cells from 1000 Algerian subjects. In 16 subjects, the cytochrome b2 reductase activity was diminished by 50%. Family studies indicated the presence of a defective allele with an overall gene frequency of 0.008. Immunologically cross-reacting material was found in red cells with low cytochrome b5 reductase activity. Leukocytes exhibited normal levels of enzyme in some families and low levels in others suggesting that at least two different deficient alleles at the DIA1 locus were present in the Algerian population. A higher prevalence of the deficient allele(s) was found in subjects of Kabyle origin.

Time-resolved fluorometry: a sensitive method to quantify DNA-hybrids.

Europium and other lanthanides can be excitated with UV-radiation, whereafter the energy is released as fluorescence, delayed in time up to 1 ms after the excitation. Eu can be used as a sensitive label in biological assays. Here we report on the application of time-resolved fluorometry to detect nucleic acid hybrids. The probe DNA was tagged with a hapten, either a fluorene or a sulfone group. After hybridization the probe DNA was detected by a two-step immunological assay with the second antibody labelled with Eu. The method is quantitative with a detection limit of 0.3 pg of actual target regions of immobilized adenovirus genomic DNA. The label was also used in sandwich hybridization, which allowed analyzing nasopharyngeal mucus for the presence of adenovirus.

Chemically modified nucleic acids as immunodetectable probes in hybridization experiments.

Guanine residues in nucleic acids can be modified by treatment with N-acetoxy-N-2-acetylaminofluorene and its 7-iodo derivative in an in vitro nonenzymatic reaction. The modified nucleic acids (ribo or deoxyribo, single or double stranded) are recognized by specific antibodies. They can be immunoprecipitated or used as probes in hybridization experiments and detected by immunochemical techniques.

DNA probe specific for Legionella pneumophila.

A procedure for preparing a DNA probe to be used in the specific detection of Legionella pneumophila by dot or colony hybridization has been devised. When total DNA from L. pneumophila was used as a radioactive probe, cross-hybridization occurred with DNA from many other species belonging to various families (including Legionellaceae, Enterobacteriaceae, Pseudomonadaceae, and Vibrionaceae). Cross-hybridizing restriction fragments in L. pneumophila ATCC 33152 DNA were identified on Southern blots. When unlabeled DNA from strain ATCC 33152 was cleaved by endonuclease BamHI, the DNA fragments cross-hybridizing with the labeled DNA from all of the other species and genera tested (or with Escherichia coli 16 + 23 S RNA) had a size of 21.4 and 16.2 kilobase pairs (major bands) and 28.0, 12.8, and 10.1 kilobase pairs (minor bands). BamHI restriction fragments of L. pneumophila DNA deprived of the cross-hybridizing fragments were pooled and used as a probe for the detection of L. pneumophila. This probe proved to be specific for L. pneumophila in colony and dot hybridization. It can potentially be used for the detection of L. pneumophila in clinical and water samples. The procedure described can be readily applied to the preparation of probes specific for phylogenetically isolated bacterial species other than L. pneumophila.

P-element distribution in Eurasian populations of Drosophila melanogaster: A genetic and molecular analysis.

Genetic and molecular investigations were carried out with Eurasian Drosophila melanogaster populations on the P-M system of hybrid dysgenesis. In 27 strains sampled from France to Middle Asia, a clear gradient exists between Western Europe, in which most modern strains are of the Q type, and eastern areas, in which M-cytotype strains predominate. Molecular analysis on individual flies was performed with two complementary probes of the cloned 2.9-kilobase P element. The results provide evidence for a gradually decreasing frequency of P elements from west to east, but the presence of P-homologous sequences has been ascertained in all of the wild M-cytotype populations analyzed. Moreover, some active P elements with GD sterility potential were revealed in the majority of M-cytotype populations when tested with a highly sensitive reference line. The gradual change in distribution of the polymorphic P family in Eurasia is discussed in relation to the structure of the elements together with the theories of P-M evolution and is interpreted as the present invasion of Eurasian populations by these elements.

Is there a PGM1 4 allele specific to Amerindian populations?

Rare PGM1 variants in Macushi and Wayampi Amerindian populations have been compared electrophoretically and by means of electrofocusing. They appear to be identical. The findings are discussed.

Synthesis of 8-(2-4 dinitrophenyl 2-6 aminohexyl) amino-adenosine 5' triphosphate: biological properties and potential uses.

We have synthetised 8-(2-4 dinitrophenyl 2-6 aminohexyl) amino-adenosine 5' triphosphate (in short : rATP-DNP), a derivative of ATP which carries a dinitrophenyl group. We show that rATP-DNP is a substrate for calf thymus deoxynucleotidyl terminal transferase (EC 2.7.7.31) and E. coli DNA polymerase I (Kornberg polymerase EC 2.7.7.7.). It can therefore be incorporated into DNA molecules by elongation from 3' ends or by nick translation. The incorporated dinitrophenyl group can be recognized by specific antibodies which can then be detected by anti-antibodies coupled to an enzyme. DNP groups could also be introduced into DNA after enzymatic incorporation of 8-aminohexyl adenosine 5' triphosphate and reaction with 1-fluoro-2-4-dinitrobenzene. Thus, DNA molecules carrying DNP groups can ultimately be revealed by enzymatic coloured reactions. Potential uses of this enzymatic labelling as a substitute to the radioactive detection of nucleic acids, are discussed.

[Rare electrophoretic variants of the proteins adenylate kinase 1, phosphoglucomutase 1 and 2, and transferrin (AK1, PGM1, PGM2, Tf) in two populations of French Guiana]. / Variants électrophorétiques rares des protéines adénylate kinase 1, phosphoglucomutase 1 et 2 et transferrine (AK1, PGM1, PGM2, Tf) dans deux populations de Guyane française.

Two small populations of inner French Guiana were investigated for red cell enzymes and serum proteins. Rare variants were found in four systems (AK1, PGM1, PGM2, Tf). Similarities between some of these variants and those found in other Amerindian populations indicate that these genetic markers may be valuable in studies of Amerindians. A mutation rate has been estimated from the results.

Hybridization on squashed flies: a method to detect gene sequences in individual Drosophila.

Specific gene sequences can be detected by DNA hybridization to individual Drosophila squashed on cellulose or nylon filters. This "squash-blot" method permits the rapid survey of DNA polymorphism in large Drosophila population samples. It could also be useful for studying chromosome aberrations, departure from diploidy, and detection of pathogenic agents in vector insects.

Extent of transcription of mouse sarcoma-leukemia virus by RNA-directed DNA polymerase.

The DNA product obtained from the endogenous RNA-directed DNA polymerase (deoxynucleosidetriphosphate:DNA deoxynucleotidyltransferase, EC 2.7.7.7) reaction of the Moloney sarcoma:leukemia viruses produced by the 78 A-1 cell line was analyzed and characterized. The extent of transcription of viral 70S RNA was measured by RNA.DNA hybridization ((32)P-viral RNA-(3)H product DNA). No double-stranded DNA was obtained. The product consisted of 95-99% single-stranded DNA with an average length of 200 nucleotides. In contrast to the results reported with avian and other RNA oncogenic viruses, it was found that the entire 70S viral RNA genome was transcribed into DNA pieces and that a small excess of the product DNA was sufficient to anneal the 70S RNA and render it totally resistant to single-stranded-specific enzyme digestion.

In situ hybridization of an acetylaminofluorene-modified probe recognized by Z-DNA antibodies in vitro.

An in situ hybridization procedure, based on the chemical modification of DNA by acetylaminofluorene (AAF), followed by a specific immunoreaction was used to localize a Z-DNA sequence isolated from the satellite DNA of Cebus appella. The AAF probe is localized on the R-band-positive heterochromatic segments of Cebus chromosomes, which strongly react with Z-DNA antibodies. The use of a nonradioactive single-stranded labeled probe confirms the reliability and the rapidity of immunochemical methods for the detection of DNA sequences on chromosomes.

Histocompatibility antigens in two American Indian tribes of French Guiana.

Two South American Indian populations were typed for HLA antigens. In each, the individuals typed were related and their genealogies were known. Determination of their genotypes was done; there seemed to be neither excess nor deficiency in homozygotes. The antigens observed, A2, A9, Aw19.2 (Aw30-Aw31), A28 for the first locus and B5, Bw15, Bw35, Bw40 for the second locus are in accordance with those previously described for other South American Indians. The two populations belong to the same primary linguistic family Tupi-Guarani and they live in the same geographic area, but there was no intertribal marriage until recently. Genetic drift can explain the differences observed.