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Biomedical subjects

D Sommer

Publications and source records attributed to D Sommer.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Neuropathologic findings in 13 deceased patients with acquired immunologic deficiency syndrome].

The neuropathological findings in 13 patients with the acquired immune deficiency syndrome (AIDS) and with AIDS related complex (ARC) are reported. Six patients presented with neurological symptoms, whereas autopsy revealed CNS involvement in nine cases. Four patients showed neither neurological nor neuropathological abnormalities. The most frequent neuropathological diagnoses were toxoplasma encephalitis (4 cases) and multiple or solitary cerebral necroses (3 cases). Long tract degeneration of the spinal cord was found in 2 cases. Cytomegalovirus infection, progressive multifocal leukoencephalopathy, primary lymphoma of the CNS, infiltration of the leptomeninges by plasmocytoma cells and a solitary metastasis of a bronchial carcinoma were diagnosed in one case each. Subacute leukoencephalitis, mentioned frequently in the literature, was not present in this material. In one case, however, status spongiosus and gliosis was found in the cortex and basal ganglia. As similar spongy changes can be seen in mice infected experimentally with retroviruses, a pathogenetic role of the human T-cell lymphotropic/leukaemia virus type III (HTLV-III) cannot be ruled out. Astrogliosis and hypertrophy of astrocytes were found in nine cases. Morphometrically, the number of astrocytes was significantly higher in AIDS patients than in control cases which were selected randomly on grounds of comparable age. Whether this finding bears some relationship with HTLV-III encephalopathy remains open to further investigation. Glial nodules were found in four cases; according to silver impregnation they were composed of microglial elements.

Acquired Immunodeficiency Syndrome↗
PubMed1986

German experimental hepatitis B vaccine--influence of variation of dosage schedule, sex and age differences on immunogenicity in health care workers.

Of the medical staff of our hospital 217 members at high risk for hepatitis B were immunized with an experimental hepatitis B vaccine and anti-HBs titers used to study the influence of two dosage schedules, age, and sex on immunogenicity. Participants were 34 years of age (mean; range, 20-61); they were divided into two groups and vaccinated three times. Group A received 42 micrograms HBsAg for each vaccination. Group B received 84 micrograms for the first and 21 micrograms for the second and third vaccinations. The seroconversion rate was 32.7% after the first, 78.8% after the second, and 95.7% after the third vaccination. The participants who failed to produce anti-HBs titer (3 IU/l; n = 9) or whose anti-HBs titers were below 50 IU/l (n = 31) were vaccinated a fourth time. Only mild side effects of injections were observed in a third of all participants, usually in the form of a sore arm. Between groups A and B there were no significant differences as far as the seroconversion rate and anti-HBs titer were concerned. Nonresponders plus low-responders accounted for 19%. Female participants produced a markedly higher anti-HBs titer than males, and the female/male ratio among non- and low-responders was 1:2; among nonresponders, 1:2.5. There was a negative correlation of the anti-HBs titer with the age of the participants. These results not only have practical consequences for revaccination policy, but also offer the opportunity to further study the genetic regulation of the immune response to a complex peptide antigen in man.

Adult↗
PubMed1986

Maternal serum alpha-fetoprotein screening for neural tube defects and other disorders using an ultramicro-ELISA. Collaborative study in Cuba and in the German Democratic Republic.

In Cuba and in the German Democratic Republic (GDR) a total of 24,412 pregnant women were tested for maternal serum alpha-fetoprotein (MSAFP) at the 16th to 20th week of gestation. An inexpensive and partly automated ultramicroliter enzyme immunoassay (ELISA) with final volumes of 10 microliter was used to analyze simultaneously 50 samples. The intraassay coefficient of variation (CV) of 5-8% and day/day CVs of 6-10.5% were obtained with a test frequency of 320 assays/day. A cut-off level of twice the median value (MoM) was chosen. An amniocentesis was done in a total of 0.5% (in the GDR) and 0.7% (in Cuba) of the screened women. The prevalence of open neural tube defects (ONTD) was calculated from the present study and was 1.43% in Cuba and 1.34% in the GDR. Through MSAFP screening 88.2% ONTD were detected. There was no therapeutic abortion of a normal fetus. The approximate cost for this program was about 2.36 marks-GDR per patient screened, or about 2,048 marks per ONTD detected.

Abortion, Spontaneous↗
PubMed1986

Possibilities and problems in genomic diagnosis of Duchenne muscular dystrophy with molecular probes.

Selected families affected with Duchenne muscular dystrophy from an extensive pedigree analysis with linked restriction fragment length polymorphisms and creatine kinase estimations are compiled to demonstrate the various counselling situations for carrier determination and prenatal diagnosis. The creatine kinase determination suffers from approximately 30% false negative values in carrier determination. The DNA analysis is limited by the uninformativity of the DNA markers and the occurrence of meiotic crossovers between the particular restriction fragment length polymorphism pattern and the Duchenne muscular dystrophy locus. The use of markers bridging the Duchenne muscular dystrophy locus, such as 754 and C7, is presently best suited for this purpose but is applicable to only a relatively small number of cases. The use of the physically closer probe, pERT 87, is much more informative althrough it too recombines with the Duchenne muscular dystrophy locus. DNA analysis allows prenatal diagnosis for unaffected boys from the restriction fragment length polymorphism pattern confined to the healthy grandpaternal X-chromosome in cases where the carrier status of the mother is established or in doubt. As in the case of carrier determination, crossover events and uninformativity of restriction fragment length polymorphisms limit the feasibility of this approach.

Alleles↗
PubMed1986

[Autopsy findings in patients with acquired immunodeficiency syndrome].

We have evaluated the autopsies of 11 patients with HTLV III/LAV-infection. The clinical diagnosis was AIDS in 10 cases and AIDS related complex (ARC) in one case. The most common infectious disease was pneumocystis carinii pneumonia, occurring in 5 cases. 3 patients showed evidence of mycobacterial infections and another three showed cytomegalovirus infections. Kaposi's sarcoma was found in 4 and other malignancies in 3 cases. Our results are in agreement with the findings of other authors.

AIDS-Related Complex↗
PubMed1985

Caudal medullary expiratory neurone and internal intercostal nerve discharges in the cat: effects of lung inflation.

In midcollicular decerebrate, thoracotomized, paralysed cats that were ventilated by a cycle-triggered pump and had an expiratory load, recordings were taken from expiratory neurones in the nucleus retroambigualis of the caudal medulla and from the internal intercostal nerves at T8-T9 levels. Expiratory neurone and internal intercostal activities had augmenting patterns of two types: (a) step-ramp (one-third of the neurones): a large initial increase of activity synchronous with inspiratory termination, followed by a ramp increase throughout the expiratory phase; (b) ramp (two-thirds of the neurones): a steady rise of activity without a sharp initial increase, discharge usually starting after a delay (as much as several hundred milliseconds) from the onset of expiration. Both types of unit pattern could occur together with each type of internal intercostal pattern. At the end of expiration, unit activity shut off abruptly just prior (0-120 ms) to the onset of phrenic discharge. The effects of pulmonary afferent discharge on unit and internal intercostal activities were evaluated by use of inflation tests: withholding inflation during the preceding inspiratory phase; maintaining inflation at the end-inspiratory level during expiration. Both tests produced lengthening of expiratory phase duration (TE), but their effects on activity differed. Following no-inflation during inspiration, the discharge onset delay was lengthened for most ramp neurones, but for only a minority of step-ramp neurones; the slope of activity augmentation did not change on the average; and the peak (end-expiratory) discharge frequency was only slightly increased. The predominant effect of maintained expiratory inflation was reduction of activity slope for ramp neurones and for a minority of step-ramp neurones, as well as increase of peak frequency; there was a moderate increase of discharge onset delay for ramp neurones, but not for step-ramp neurones. The lengthening of TE produced by no-inflation in the preceding inspiration was associated with lengthening of the durations of both the discharge onset delay and the discharge burst, but there was no correlation between changes of these two variables. We observed a 'reversal phenomenon': moderate inflation facilitated activity, whereas higher inflation levels depressed activity, as demonstrated by: comparison of effects of maintained expiratory deflation (removal of the expiratory load) and of maintained expiratory inflation, both of which reduced activity; comparison of effects of phasic expiratory inflations having different magnitudes.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1981

Neurophysiological background of central neural cardiovascular-respiratory coordination: basic remarks and experimental approach.

This paper is comprised of a review of past contributions and their theoretical consequences and a presentation of new results in studies of the origin of sympathetic rhythms and tone. Two basic mechanisms are involved: a primary intracentral coupling with the main cardiovascular-respiratory rhythm (MCRR) generator and a secondary reflex coupling. It was found that the activity and rhythms of certain sympathetic efferents, such as the cervical sympathetic, are closely related to the MCRR. Other efferents, such as the renal sympathetics, are loosely linked and follow drives from other circuits in the genesis of their rhythms and tone. New experimental evidence is given that rhythmic and tonic activity in sympathetic nerves originates from several sources. Hence central respiratory-autonomic systems interaction is not explained by simplistic concepts.

Animals↗
PubMed1979

Diagnosis and treatment of migraine in children.

We here enumerate criteria that we believe are suitable for the diagnosis of migraine in children. Using these criteria, we identified 84 children retrospectively, and studied their illness for 3 to 9 years thereafter. The majority were male, and 47 patients had frontal headaches. EEGs were performed in 64 children: 17 were paroxysmal, but 7 patients never developed seizures. Referral to a neurologist occurred when there was a marked increase in the frequency or severity of headaches. Irrespective of the form of treatment, about one-half of all patients had more than a 50% reduction in headache frequency in the 6 months following their initial visit to a neurologist.

Adolescent↗
PubMed1979

Negative surplus charge of coated erythrocytes.

The effect on the net negative surface charge of single or multiple coating of erythrocytes was studied on human group A red cells previously washed and fixed. Single coating with either group A antiserum or protectin decreased the electrophoretic mobility of erythrocytes by 16% and 13%, respectively. Following an incubation in group A glycophorin or bovine submaxillary mucin of agglutinin coated cells, the electrophoretic mobility was restored or slightly increased compared with uncoated erythrocytes. Upon repeating this scheme, the second agglutinin binding again reduced these cells' cytophoretic mobility, and they were accelerated once more by a second coating with acid glycoprotein. Intensity and homogeneity of colloidal iron staining of uncoated and variously coated erythrocytes reflected their electrophoretic retardation and acceleration, respectively.

ABO Blood-Group System↗
PubMedDate not supplied

Phylloid pigmentary pattern with mosaic trisomy 13.

In most patients with hypomelanosis of Ito, the hypopigmentation is characterized by narrow bands following the lines of Blaschko. We report a 13-year-old severely retarded girl with leaf-shaped patches of hypopigmentation on the back together with short stature, scoliosis, facial dysmorphism, and asymmetrical leg length. The cytogenetic examination of both lymphocytes and fibroblasts demonstrated a mosaicism of 46,XX/47,XX+13. This result was confirmed by in situ hybridization using a chromosome 13-specific library in interphase cells. The pigmentary disturbance of our patient was similar to the phylloid pattern (type 3) of the classification of pigmentary patterns postulated by Happle. This type has been described in four patients so far, along with additional anomalies and a chromosomal mosaisicm in two patients.

Abnormalities, Multiple↗