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Biomedical subjects

H Spiegel

Publications and source records attributed to H Spiegel.

18 recordsLinked to original sources
PubMed1992

Distribution of human immunodeficiency virus (HIV) in the CNS of children with severe HIV encephalomyelopathy.

The presence and distribution of human immunodeficiency virus (HIV) were examined in the CNS of two children with severe HIV encephalitis and myelitis. Using polymerase chain reaction-mediated DNA amplification and subsequent Southern analysis, proviral HIV gag sequences were identified in brain tissue of both patients. In situ hybridization using antisense oligonucleotide probes revealed abundant HIV gag and env/nef RNAs selectively in areas with histopathological evidence for HIV-induced tissue damage. The spinal cord of one patient exhibited a striking subpial accumulation of HIV RNAs strongly suggestive of a liquorigenic spread of the infection. HIV RNAs were typically associated with cells of the monocyte/macrophage lineage, as shown by a combined immunohistochemical and in situ hybridization procedure. The present study supports the view that the pattern and distribution of HIV-induced brain lesions is largely determined by the extent of focal HIV replication within the CNS.

Base Sequence↗
PubMed1992

Follicular dendritic cells are a major reservoir for human immunodeficiency virus type 1 in lymphoid tissues facilitating infection of CD4+ T-helper cells.

Human immunodeficiency virus type 1 (HIV-1) infection causes progressive depletion of CD4/HIV-receptor-positive T helper lymphocytes, ultimately leading to AIDS. The major HIV reservoir and site of T-helper cell infection in lymphoid tissues, however, has remained poorly defined. The authors used in situ hybridization in combination with immunohistologic labeling techniques to identify the phenotype of HIV-infected cells in lymph nodes from patients at different stages of HIV-infection. The number of HIV-infected macrophages, widely considered the major site of HIV replication, was extremely low. There was no evidence for HIV-infection of endothelial and interdigitating reticulum cells. However, HIV RNA was found in small but consistent proportions of CD45RO-positive T cells and in the vast majority of follicular dendritic cells (FDC) in a pattern suggestive of active infection in addition to HIV-immunocomplex trapping on cell membranes. FDC may therefore be a major HIV reservoir and since T-helper cells travel through the FDC meshwork during their migration within lymphoreticular tissues, it appears likely that HIV-replicating T cells may infect FDC, which then infect new T cells, thus causing a gradual dissemination of the virus to all FDC and thereby a steadily increasing infection of T-helper/memory cells within germinal centers. This results in CD4+ T cell depletion, and ultimately, in immunodeficiency.

Adult↗
PubMed1992

Personality style and hypnotizability: the fix-flex continuum.

Since Mesmer, there has been much confusion about the inter-relationship between an individual's degree of hypnotizability, the personality style of the individual and the importance of the therapeutic strategy. Empirical and experimental research supports the hypotheses that there are: 1) biopsychosocial components of hypnotizability on a continuum ranging from ecologically insensitive (not modifiable by external stimuli) to ecologically sensitive (very modifiable by external stimuli); 2) biopsychosocial components that can be measured to identify an individual's degree of hypnotic capacity and responsivity; 3) distinct personality styles which correlate with low, mid-range and high hypnotizability on a fix (ecologically insensitive)-flex (ecologically sensitive) continuum; and 4) different clinical syndromes which correlate with these categorical distinctions. We propose that measuring hypnotizability and personality style is a way to clarify diagnosis and choose appropriate treatment strategies to maximize existing biopsychosocial resources of an individual with a specific problem in a particular context.

Female↗
PubMed1992

Neuropathology and pathogenesis of HIV encephalopathies.

The nervous system is frequently affected in patients with the acquired immune deficiency syndrome (AIDS). In addition to opportunistic CNS infections and cerebral lymphomas, approx. 20% of the patients develop HIV-associated encephalopathies. Two major histopathological manifestations are observed. HIV leukoencephalopathy (progressive diffuse leukoencephalopathy) is characterized by a diffuse loss of myelin in the deep white matter of the cerebral and cerebellar hemispheres, with scattered multinucleated giant cells and microglia but scarce or absent inflammatory reaction. HIV encephalitis (multinucleated giant cell encephalitis) is associated with accumulations of multinucleated giant cells, inflammatory reaction and often focal necroses. In some patients, both patterns may overlap. In order to identify the HIV genome in the CNS, brain tissue from 27 patients was analyzed for the presence of HIV gag sequences using the polymerase chain reaction (PCR) and primers encoding a 109 base pair segment of the gag gene. Amplification of HIV gag succeeded in all 5 patients with clinical and histopathological evidence for HIV encephalopathy but was negative in the 20 AIDS patients with opportunistic bacterial, parasitic and/or viral infections or with cerebral lymphomas. These results strongly suggest that the evolution of histopathologically recognizable HIV-encephalopathies closely correlates with the presence and/or tissue concentration of HIV. Since there were no cases with amplified HIV DNA in the absence of HIV-associated tissue lesions, we conclude that harboring and replication of HIV in the CNS rapidly causes corresponding clinical and morphological changes of HIV-associated encephalopathies. In two children with severe HIV encephalomyelitis, large amounts of HIV gag and env transcripts were detected in affected areas of the brain and spinal cord by in situ hybridization.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Dementia Complex↗
PubMed1991

[Sudden blindness in an AIDS patient. Simultaneous infection with cytomegalovirus and herpes simplex viruses and development of malignant non-Hodgkin lymphoma].

A 50 year old patient with non-diagnosed HIV-infection at onset of his illness developed impairment of vision and temporary double vision combined with severe hemianopsia. With normal fundus and suspicious Herpes simplex iritis therapy with Acyclovir was started. Primarily the patient showed a good response to the therapy and loss of vision could be prevented. After 4 weeks CMV-retinitis developed. In spite of Gancyclovir therapy manifestation of total loss of vision after 6 weeks. Autopsy demonstrated signs of simultaneous a CMV-infection of the retina and a herpes simplex-infection of the optic nerve combined with a Non-Hodgkin-Lymphoma of the optic tract.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[The central nervous system of infants born to HIV-positive mothers-- neuropathology, immunohistochemistry in in situ hybridization].

The central nervous system (CNS) of 12 fetuses from human-immunodefiency-virus-seropositive mothers was investigated. Postconceptional ages ranged between 15 and 21 weeks. 3 preterm infants born to HIV positive mothers whose survival ranged from 6 hours to 6 months were included in the study. In all cases, the development of the CNS was macroscopically normal. The microscopic examination showed many ectopic neurons indicating disturbances of normal neuronal migration. As a regular finding there was a significant increase in microglia in all areas of the CNS but no microglial nodules were found. In all cases haematogenous monocytes were scattered in the perivascular space of the cerebral parenchyma as well as in the chorioid pexus. The virus-antigen p24 could neither be detected immunohistochemically in the paraffin sections nor in the frozen material of the brain or by in-situ-hybridization. In contrast, in five of the cases investigated the placenta showed macrophages, socalled Hofbauer cells with p24-associated antigen.

Antigens, Viral↗
PubMed1991

[Lymphoid tissues and AIDS: role of lymphocytes and follicular dendritic cells (FDC)].

Currently discussed models of AIDS pathogenesis attribute a pivotal role to HIV-variants developing in T cells during the course of the disease resulting in an increasingly rapid depletion of the infected T cells. Such models do not however explain the morphological findings observed in AIDS lymphadenopathy. To clarify the significance of the hyperplasia and subsequent destruction of the lymphoid follicles in HIV-related lymphadenopathy, we used in situ hybridization in combination with immunohistological labelling techniques to identify the phenotype of HIV-infected cells in lymph nodes. In addition to few T helper cells, mainly in germinal centres, large amounts of HIV-RNA were found in CD4-negative follicular dendritic cells (FDC) rather than in macrophages or other cells. This finding is well in accordance with the recent observations made by other authors suggesting that purified FDC can be infected with HIV in vitro. Furthermore, TNF alpha expression is localized mainly in centroblasts (activated B cells) of germinal centres. TNF alpha, released by antigen-activated B cells in vitro, has been shown to induce HIV replication in latently infected T cells. On the basis of these observations we propose that latently infected CD4+ T cells, having entered germinal centres, start HIV replication under the influence of cytokines present in this microcompartment of all lymphoreticular tissues. Here the T cells infect FDC which, in turn, pass on the virus to new healthy T helper cells. This model may explain both peculiarities of the lymphadenopathy syndrome as well as the long latency period of HIV-infection, ultimately leading to AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Legal principles in the psychiatric assessment of personal injury litigants.

The authors review the legal principles that a psychiatrist must understand in assessing the emotional and psychiatric sequelae of a personal injury leading to a litigation claim. The principles of the establishment of fault or liability, the assessment of pain and suffering, causal connection, the credibility of the plaintiff, the credibility of the expert witness, the determination of prognosis, the award of damages, and the adversarial system are discussed. An appreciation of these principles will enable psychiatrists to provide assessments that will be useful to the legal system in arriving at a fair and accurate determination of the compensation to which a victim is entitled.

Accidents, Traffic↗
PubMed1987

Transposition of Tn4551 in Bacteroides fragilis: identification and properties of a new transposon from Bacteroides spp.

Tn4551, a clindamycin resistance (Ccr) transposon from the R plasmid pBI136, was cloned onto an Escherichia coli-Bacteroides shuttle vector which could replicate normally in E. coli but was maintained unstably in Bacteroides fragilis. To aid in cloning and to ensure maintenance of Tn4551 in E. coli, a kanamycin resistance determinant (Kmr) was inserted in the transposon. The transposon-bearing shuttle vector pFD197 was transformed into B. fragilis 638, and putative insertions of Tn4551::Kmr were identified by screening for resistance to clindamycin and plasmid content. Southern hybridization analyses were used to verify integration of the transposon in the B. fragilis chromosome, and the frequency of insertion was estimated at 7.8 X 10(-5) events per generation. In 57% of the isolates tested a second integration event also occurred. This second insertion apparently involved just a single copy of the 1.2-kilobase repeat sequence which flanks the transposon. In addition, Tn4551::Kmr appeared to function as a transposon in E. coli. Evidence for this was obtained by the isolation of transposon insertions into the bacteriophage P1 genome. Finally, the transposon vector, pFD197, could be mobilized to other B. fragilis strains in which transposition was detected. Mobilization from the strain 638 background was via a conjugation like process, but occurred in the absence of known conjugative elements or other detectable plasmids. This result suggested the presence of a host-encoded transfer system in this B. fragilis strain.

Bacteroides fragilis↗
PubMed1978

[Photoaugmentation. a photobiological phenomenon (author's transl)].

The phenomenon of photoaugmentation was investigated in 37 male and female patients. UVA, UVB and UVC was applied with a high intensity grafting monochromator. Photoaugmentation could be induced following UVA plus UVB immediately or dissociated up to 3 h, but not after 24 h (15 J/cm2 lambda 351 less than or equal to 389 nm [UVA] + 13 mJ/cm2 lambda 290 less than or equal to 310 nm [UVB] = 1/2 MED). Simarily the reversed application of UVB plus UVA lead to photoaugmentation. With UVA plus UVC, photoaugmentation could not be elicited in every patient. Moreover, photoaugmentation was demonstrated in albino rabbits using a new light apparatus with a liquid filled light conducting core. Photoaugmentation seems to be an important biological phenomenon in association with sunburn, pigmentation, photoxicity, phototherapy, photochemotherapy, and UV-light induced cutaneous premalignanacies and malignancies.

Animals↗
PubMed1978

Neurogenic and hysterical seizures in children and adolescents: differential diagnostic and therapeutic considerations.

For patients whose seizures are not controlled by medication alone, psychotherapeutic intervention can sometimes play a useful adjunctive role in both differential diagnosis and treatment. Diagnostic issues include the differentiation between neurogenic and hysterical seizures as well as the delineation of the possible role of psychogenic stress in triggering neurogenic seizures. Therapeutic considerations focus on the alleviation of precipitating stresses as well as the development of a sense of mastery in the patient.

Adolescent↗
PubMed1976

Age differences in vitamin B6 status of 617 men.

The effect of age on vitamin B6 metabolism was studied in 617 community-dwelling subjects, ages 18 to 90. These are, for the most part, clinically healthy, educated men whose intake of nutrients is not limited by economic factors. Plasma pyridoxal phosphate (PLP) was used as the primary criterion of vitamin B6 status. About one-third of the subjects were taking supplementary vitamins on their own initiative. The amount of pyridoxine-HCl varied from 0.1 to 105 mg/day. The average plasma PLP of the men not taking a supplement (N = 414) was 12.3 +/-0.3 ng/ml, with 25% of the values below 7.5 ng/ml and 7% below 5 ng/ml. There was a statistically significant decrease in plasma PLP with age of 0.9 ng/ml per decade. For those taking a supplement, the average plasma PLP was 20.5 +/- 1.0 ng/ml, with only 8% of the values below 7.5 ng/ml and none below 5 ng/ml. Glutamic-oxaloacetic transaminase activity in plasma (PGOT) and erythrocytes (EGOT) was determined on all subjects. The ratio of EGOT with in vitro stimulation by PLP to EGOT actual (alpha-EGOT) was also studied. These studies provide the most extensive normative data on vitamin B6 status available on men in the adult years of life.

Adolescent↗