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Biomedical subjects

C Lang

Publications and source records attributed to C Lang.

At least 19 recordsLinked to original sources
PubMed1992

Neurotoxicity of solvent mixtures in spray painters. II. Neurologic, psychiatric, psychological, and neuroradiologic findings.

A multidisciplinary cross-sectional study was performed to examine the chronic neurotoxicity of organic solvents. Participating in the study were 105 persons employed as spray painters and having long-term solvent exposure (10-44 years) and a control group consisting of 58 construction workers, electricians, and plumbers without occupational contact to solvents. Samples were matched for age, preexposure intelligence level, occupation, and socioeconomic status. After controlling for potentially non occupational confounding factors (neuropsychiatric diseases, metabolic disorders, high blood pressure, alcohol intake) 83 spray painters and 42 controls were entered finally into the study. The evaluation included work history, self-rating questionnaire, neurologic investigation, psychiatric analysis using the Present State Examination (PSE), psychological testing, and computerized axial tomography (CAT) of the brain. Physical and neurologic examinations demonstrated no case of overt disorders of the central or peripheral nervous system. An important result of the psychiatric analysis was that the syndromes "special features of depression" and "loss of interest and concentration" occurred significantly more frequently among spray painters than among controls. Further analyses demonstrated an association with chronic exposure over 30 years and repeated acute neurotoxic effects during solvent exposures. Neither psychological nor performance tests demonstrated any statistically significant differences in the performance sets after adjustment according to premorbid intelligence level; this finding supports the presumption of only a low grade of mental dysfunction. Correlation analyses indicated a relationship between subjective health complaints and long-term solvent exposure; however, the effect of age cannot be completely ruled out.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Antibacterial in vitro-activity of meropenem against 200 clinical isolates in comparison to 11 selected antibiotics.

The antimicrobial activity of meropenem, a new parenteral carbapenem, was tested in vitro by an agar dilution method against 200 clinical isolates (gram-negative/positive aerobes and anaerobes). Meropenem was compared with imipenem, ceftazidime, cefotaxime, piperacillin, ciprofloxacin, gentamicin; and metronidazole, cefoxitin, chloramphenicol, clindamycin, vancomycin when appropriate. Meropenem and imipenem exhibited an extended spectrum of activity with low minimal inhibitory concentrations (MICs). Only one strain each of Enterococcus faecium and Pseudomonas (Xanthomonas) maltophilia were resistant. Of the carbapenems, imipenem was slightly more active against Enterococcus faecalis, Streptococcus agalactiae, and staphylococci, but meropenem was obviously more active against enterobacteriaceae and Clostridium perfringens. Both, meropenem and imipenem had similar activities towards Pseudomonas aeruginosa, Acinetobacter calcoaceticus, Streptococcus pyogenes and Bacteroides sp. All other antibiotics tested were less potent than the carbapenems with the exception of ciprofloxacin which generally exhibited similar antibacterial activities, except for anaerob microorganisms.

Anti-Bacterial Agents↗
PubMed1992

Rapid development of giant aneurysm at the base of the brain in an 8-year-old boy with perinatal HIV infection.

An 8-year-old boy with perinatal HIV infection developed a large fusiform aneurysm in the circle of Willis two years prior to death which was confirmed by radiological studies. The postmortem examinations revealed a predominantly intimal, proliferative lesion, and partial destruction of the internal elastic lamina in the involved arteries. Within the intima hyperplasia of fibroblasts and smooth muscle cells was observed. No inflammatory alterations, no granulomas and no multinucleated giant cells could be noted in the vascular walls and in the cerebral parenchyma. A small ischemic infarct was present in the left thalamus. Cerebellum, brainstem and medulla showed multiple areas of progressive multifocal leukoencephalopathy (PML). Immunohistochemistry with anti-gp41, a monoclonal antibody against HIV envelope did not exhibit any positive results. These findings implicate that the vascular lesion might be attributed to primary infection of the brain by HIV which led to a defect of elastic lamina and consecutive intimal hyperplasia. A second hypothesis could be based on the effect of extremely high dose AZT therapy avoiding inflammatory reaction after HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Fecal occult blood--does a hemoglobin-specific tests improve the diagnosis of relevant colonic neoplasms?].

The object of this study was to assess whether an immunological test specific for human hemoglobin improves the detection of bleeding from colorectal tumors as compared to a conventional guaiac test for occult fecal blood. We examined one stool sample from 134 patients prior to a complete colonoscopy by the Colo-Immun-Test (CI) as well as the Colo-Rectal-Test (CR). CI proved to have a higher sensitivity for occult bleeding from all colonic lesions, but this difference was not statistically significant. There was, however, no difference in the sensitivity of the two tests in detecting bleeding from relevant colonic neoplasms. In this study the immunological CI did not improve the detection of occult fecal blood loss due to adenomas and carcinomas of the colon in comparison with CR.

Colorectal Neoplasms↗
PubMed1991

[Ocular manifestations in a patient with Cockayne syndrome and simultaneous reduced DNA repair].

A 14 year old white boy presented with the typical clinical findings of Cockayne syndrome. Photodermatosis was known since the third week of life. He had disproportionate short stature with a short trunk, long limbs and flexion contractures of the large joints. He also was cachectic and prematurely aged. He had a typical facies. The hearing was slightly impaired. The prominent ocular findings were corneal opacifications, salt and pepper like retinal pigment epithelial changes and optic atrophy. On fibroblast culture the DNA repair activity is usually normal in patients with Cockayne syndrome. The DNA repair activity in our patient however was markedly reduced to 25% of normal. On lymphocyte culture a significantly increased 4-nitroquinoline-1-oxide sensitivity (cytotoxicity and increased break-rate) was found. These findings indicate that the boy has a specific variant of Cockayne syndrome with simultaneously reduced DNA-repair activity.

Adolescent↗
PubMed1991

[Psychometric speech studies in Alzheimer's dementia with the Aachen aphasia test].

Dementias of the Alzheimer type seem to be frequently accompanied by language disturbances. These may represent a feature which can be of help in distinguishing them from other types of dementias. We used the Aachen aphasia test in 32 patients suffering from Alzheimer dementia according to research criteria, and a mixed sample of 35 patients suffering from other dementias. From these 2 groups 2 subsamples of 21 patients each were gathered which were comparable with regard to age, disease onset, level of education, verbal intelligence and severity of senility. Nevertheless it was possible to distinguish the groups to a certain degree on grounds of psychometric language criteria alone. Alzheimer patients were more severely handicapped communicatively, less dysarthric, produced more automatisms and discretely more phonemic paraphasias with fluent speech which was sometimes paragrammatic. A relatively better level of repetition compared to the Token test and written language was fairly specific. A computer-assisted classification yielded language disturbances similar to Wernicke's aphasia more often than with non-Alzheimer dementias. We found no Alzheimer patients with a Broca's type of language disorder, while amnestic and global types were bound to the level of overall impairment to a certain degree. The significance of these results with regard to the use of psychometric language test in the dementias, particularly Alzheimer's dementia, and to differential diagnostic considerations are reviewed briefly.

Aged↗
PubMed1990

[Encephalitis in Legionella bozemanii pneumonia].

A 44-year-old man, a known alcoholic and heavy smoker, was hospitalized with high fever and respiratory failure which a few hours later required intubation and artificial ventilation, although the chest x-ray had been unremarkable. Later serial chest x-ray films showed intrapulmonary infiltrations, while Legionella Bozemanii was demonstrated by direct immunofluorescence. Cranial computed tomography was unremarkable, despite the onset of tetraparesis and a severe midbrain syndrome. Cerebrospinal fluid contained merely mild lymphocytic pleocytosis. However, magnetic resonance imaging revealed symmetrical demyelinization foci in the brainstem as a sign of encephalitis. The neurological deficits regressed almost completely after several weeks of antibiotic treatment and rehabilitation measures over several months.

Adult↗
PubMed1990

[Diagnosis of Alzheimer's dementia].

Alzheimer's disease is the most common form of dementia in the elderly. Owing to a lack of accurate easily determined clinical criteria, neuropathological findings remain decisive for establishing the diagnosis. However, full utilization of all the presently available methods, such as history taking, physical examination, neurological and mental status, psychological testing, laboratory examinations, additional procedures involving the use of diagnostic equipment, can result in a diagnostic accuracy of about 90%. The very wide spectrum of possible differential diagnostic possibilities can be greatly reduced by the judicious use of a few selective examinations. Here, the possibilities available in the doctor's office are better than ever before. Of decisive importance for the patient is to consider the possibility of dementia, and to exclude treatable causes as soon as possible.

Alzheimer Disease↗
PubMed1990

[Diagnostic differentiation of dementia diseases by modern imaging procedures].

We present a review on recent neuroimaging techniques, like x-ray computed tomography (XCT), magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission tomography (SPECT) in dementia and related diseases. Significant new findings have been obtained using techniques reflecting proton density, regional brain perfusion and brain metabolism. In dementia of the Alzheimer type, for example, temporoparietal and sometimes also frontal reductions in cerebral blood flow and metabolism are characteristic. The infarctions found in multi-infarct dementia are especially well visualized on T2-weighted MRI images. Pick's disease is characterized by brain atrophy and decrease of radiotracer activity in the frontal lobes. In huntington's chorea the metabolic rate on PET scan in the area of the caudate nuclei may be reduced even before signs and symptoms become apparent. Furthermore, neuroimaging provides us with fairly typical finding in Creutzfeld-Jakob's disease, alcoholic dementia, Wilson's disease, hydrocephalus, Parkinson's disease, progressive supranuclear ophthalmoplegia, Fahr's disease, and the olivopontocerebellar ataxias. Neuroimaging techniques, however, have always to be interpreted in conjunction with clinical findings, thus disclosing their full range of information.

Brain↗
PubMed1990

Neuropsychological findings in treated Wilson's disease.

Seventeen patients, treated for Wilson's disease (WD), underwent a set of neuropsychological tests and were compared with a closely matched control group. There were clear differences between the groups (chi 2-test, p less than 0.0001). Wilson patients with only hepatic involvement, however, did not at all differ from their controls. Wilson patients with neuropsychiatric signs differed from controls on a reasoning test (p = 0.0016), and the entire WD group differed on a perceptual speed task (p = 0.0025). Compared to normal test values, however, the patients' group means were all within plus or minus one standard deviation from the normal mean. Special testing procedures and construction of the test battery excluded a factor of motor deficits as a major cause for the differences. The neuropsychological findings are viewed in relation to other findings in patients with motor disorders and predominantly subcortical lesion sites. Wilson's disease may be a dementing condition, but not when treated adequately.

Adolescent↗
PubMed1990

The leucine zipper domain of avian cMyc is required for transformation and autoregulation.

Small deletions of 7 to 48 amino acids have been generated in the leucine zipper domain of the avian cMyc protein and the mutant cMyc proteins expressed using an avian retroviral vector. Retrovirally encoded cMyc protein transforms primary chick embryo fibroblasts and leads to abnormal regulation of the endogenous c-myc gene. Deletion of the most C-terminal leucine of the zipper motif confers a partial phenotype affecting some but not all parameters of transformation. Complete loss of transforming activity results from deletion of further leucine residues, including one which is not part of the heptad repeat. In cMyc transformed cells endogenous c-myc mRNA is expressed at a low level and is abnormally refractory to induction by serum stimulation. In contrast, a non-transforming cMyc protein which lacks the zipper does not affect normal c-myc expression. These results demonstrate that the leucine zipper domain of avian cMyc is required for both transformation and autoregulation, and suggests that essential leucine residues within the motif may be spaced differently from those in the zippers of Fos and Jun.

Amino Acid Sequence↗
PubMed1989

Foix-Chavany-Marie-syndrome--neurological, neuropsychological, CT, MRI, and SPECT findings in a case progressive for more than 10 years.

In a 66-year-old woman signs and symptoms of bilateral opercular syndrome (Foix-Chavany-Marie-syndrome) developed progressively over a period of more than 10 years. Facio-linguo-velopharyngeo-masticatory diplegia with automatic-voluntary dissociation was accompanied by motor aphasia and oral apraxia leading to a state of almost complete anarthria. Although it initially resembled the anterior biopercular syndrome there are also features indicating involvement of the posterior opercula. Although the aetiology remains obscure without pathological data, a bilateral focal brain atrophy is assumed. This is probably the first case documented by MRI and SPECT.

Aged↗
PubMed1989

The interaction of human papillary and reticular fibroblasts and human keratinocytes in the contraction of three-dimensional floating collagen lattices.

Fibroblasts derived from the papillary and reticular dermis of human skin and human keratinocytes show differences in their abilities to contract floating three-dimensional gels constructed from type I collagen. Reticular fibroblasts produce greater gel contraction than papillary fibroblasts. When equal numbers of papillary and reticular fibroblasts are mixed in the gels, papillary fibroblasts consistently inhibit gel contraction by reticular fibroblasts indicating interaction between these cell types in the contraction process. Surprisingly, keratinocytes alone produce greater gel contraction than that produced by either fibroblast type. Cooperativity in the gel contraction process is observed when fibroblasts are incorporated into the collagen matrix and keratinocytes are seeded onto the gel surface. Keratinocytes and dermal fibroblasts adhere to the collagen fibril to induce gel contraction by different mechanisms. Fibroblast contraction of collagen gels does not require fibronectin but is a serum-dependent reaction. In contrast, keratinocyte contraction of collagen gels occurs in a serum-free environment. Polyclonal, affinity-purified antibodies to human plasma fibronectin at high concentrations do not inhibit gel contraction by keratinocytes, making unlikely the possibility that fibronectin synthesized by the keratinocyte is a significant factor in the gel contraction process. We are currently examining the possibilities either that keratinocytes are synthesizing other adhesion proteins or that receptors on the cell surface can interact directly with the collagen fiber.

Cell Adhesion↗
PubMed1989

Is Wilson's disease a dementing condition?

A case presentation in this journal by Rosselli, Lorenzana, Lasselli and Vergara (1981) has raised the issue of intellectual deterioration in Wilson's Disease. Relevant findings in the recent literature are discussed.

Dementia↗