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R Heimann

Publications and source records attributed to R Heimann.

At least 55 records · Page 3Linked to original sources
PubMed1991

Quantitative nuclear cell image analyses of thyroid tumors from archival material.

Sixty-three sections of Feulgen-stained thyroid cell nuclei from paraffin-embedded material, including five multinodular goiters, 10 adenomas, 36 papillary carcinomas, seven follicular carcinomas, and five medullary carcinomas were analyzed by means of the SAMBA 200 (TITN, Grenoble, France) cell image processor. This was done in order to obtain nuclear characteristics of papillary versus follicular carcinomas. The nuclear features were assessed by morphometric, densitometric, and textural parameters. Our preliminary results indicate that the cell nuclei from typical histopathologic specimens of follicular thyroid cancers belong to a larger thyroid cell nuclei population corresponding to the histopathologic family of papillary thyroid cancers. This follicular neoplastic cell nuclei population appears to be quite distinct from the typical medullary neoplastic cell nuclei population which also belongs to the papillary neoplastic cell nuclei population. It appears that there is a specific papillary cell nuclei subpopulation containing typical hypochromatic cell nuclei. We also observed a dramatic increase in nuclear size and hyperchromatism between normal (multinodular goiters) and neoplastic (carcinomas) thyroid tissues, with the benign tissues (adenomas) showing intermediate nuclear characteristics.

Adenocarcinoma↗
PubMed1989

Anaplastic small cell (oat cell) carcinoma of the tonsils: report of two cases.

Two cases of anaplastic small cell (oat cell) carcinoma of the tonsils are presented. In the first, cervical metastases preceded the manifestation of the primary tumour by 2 years. In case 2 the tonsillar carcinoma was accompanied by a bronchial tumour of the same histological type and by cervical and axillary metastases. Positive Grimelius stain, positive immunohistochemical staining for chromogranin A and neurone-specific enolase and the presence, in case 1, of membrane-bound granules indicate that these tumours display many similarities with neuroendocrine carcinomas even if they originate from pluripotential ductal cells of tonsillar minor salivary glands and not from Kulchitsky-like cells.

Aged↗
PubMed1988

Hereditary intestinal neurofibromatosis. I. A distinctive genetic disease.

Intestinal neurofibromatosis without other manifestations of von Recklinghausen's neurofibromatosis was found in a multigeneration family. Neurofibromas were strictly limited to the intestine. Onset of symptoms was delayed until adulthood and some gene carriers remained asymptomatic into their middle or late adult years. One other family with intestinal neurofibromatosis has been described in 1966. No symptomatic male is yet known, although an asymptomatic male in our family is an obligate gene carrier. The gene for intestinal neurofibromatosis may be incompletely penetrant and its expression varies even in symptomatic patients. No male-to-male transmission has been recorded to rule out X linkage. Intestinal neurofibromatosis presents as a distinctive dominant phenotype with an increased risk of intestinal problems including bleeding, intussusception and obstruction.

Adult↗
PubMed1988

Hereditary intestinal neurofibromatosis. II. Translocation between chromosomes 12 and 14.

A translocation was found in members of a family with intestinal neurofibromatosis, a rare dominant disorder phenotypically distinct from von Recklinghausen neurofibromatosis. The translocation was reciprocal between chromosomes 12 and 14. Four of 5 family members carrying the gene for intestinal neurofibromatosis had the translocation. This may be due to change alone or linkage of the gene for intestinal neurofibromatosis to one of the translocation breakpoints in chromosome bands 12q13 and 14q13.

Chromosomes, Human, Pair 12↗
PubMed1987

Primary malignant lymphomas of the thyroid. A brief review.

Primary lymphoma of the thyroid is a rare disease, occurring predominantly in elderly women but it is more and more reported in younger generation and this seems to reduce the female preponderance. Clinically it is characterized by a rapid and diffuse enlargement of the thyroid with hoarseness, dysphagia and local tenderness. There is a frequent coexistence of Hashimoto's thyroiditis with presence of autoantibodies. This latter disease has to be considered as a prelymphomatous condition. The differential diagnosis between the two is not always easy. The new functional classification of non hodgkin's lymphomas can be applied successfully in primary lymphomas of the thyroid: they allow to establish a prognosis and demonstrate that most of these lymphomas are B-cell derived and of follicular center cell origin. The diagnosis can be made by means of a biopsy and sometimes by fine needle aspiration.

Aged↗
PubMed1987

[Liver biopsy].

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Biopsy↗
PubMed1985

Microtubule-associated proteins bind specifically to the 70-kDa neurofilament protein.

Morphological and biochemical evidence have suggested that the components of the neuronal cytoskeleton, microtubules and neurofilaments (NF), interact with each other. Microtubule-associated proteins (MAPs) are plausible candidates for mediating some of these interactions and have been shown to bind to neurofilaments, as well as induce the formation of a viscous complex between neurofilaments and microtubules. By binding 32P-labeled MAPs to neurofilament proteins, which were transferred electrophoretically to nitrocellulose, we determined that, of the three neurofilament subunits, only the core NF70 subunit bound MAPs. The binding to electrophoretically transferred NF70 was specific, saturable, and reversible. Binding parameters were estimated by binding 32P-labeled MAPs to purified NF70 immobilized on nitrocellulose. Approximately 1 mol of MAPs bound per 45 +/- 15 mol of NF70 with an approximate Kd approximately 2.0 +/- 0.9 X 10(-7) M (n = 8). Reassembled filaments in suspension were used to confirm the specific binding. Tubulin and NF70 apparently bind to different sites on MAPs.

Animals↗
PubMed1985

Estrogen receptor expression in serially cultivated rat endometrial cells: stimulation by forskolin and cholera toxin.

Serially propagated with 3T3 feeder layer support, epithelial cells derived from normal rat endometrium expressed estrogen receptor activity. Specific binding of 17-beta-estradiol was in the range of 30-60 fmol/mg of protein and was of high affinity (Kd = 0.3 nM). A survey of cell lines derived from several other normal epithelia showed that rat vaginal and human cervical cultures also had high-affinity estrogen receptors (6-13 fmol/mg of protein), while rat epidermal and esophageal cells had no detectable activity. In the endometrial cultures, receptor levels were elevated nearly two- to fourfold by cholera toxin or forskolin in the medium. This effect was detectable after 4 hr but not 1 hr of treatment and did not occur in the presence of cycloheximide. We conclude that serially cultivated rat endometrial cells retain hormonal properties expressed in vivo while exhibiting some keratinocyte character. These cells may provide a useful model for study of receptor modulation.

Animals↗
PubMed1984

Iodide organification defect in a cold thyroid nodule: absence of iodide effect on cyclic AMP accumulation.

A follicular adenoma of the thyroid was 'hot' one hour after 99mTc pertechnetate administration, but 'cold' 24 h after 131I iodide administration. Incubation of the tissue in vitro demonstrated a defect in iodide binding to proteins that was abolished by addition of an H2O2 generating system. In this tissue iodide failed to inhibit TSH-induced cyclic AMP accumulation. The results show that iodide oxidation is required for its inhibitory action on cyclic AMP accumulation in human thyroid.

Adenoma↗
PubMed1983

Rat esophageal and epidermal keratinocytes: intrinsic differences in culture and derivation of continuous lines.

Serially cultivated with 3T3 feeder layer support as colonies of stratified squamous epithelium, rat epidermal and esophageal epithelial cells were readily distinguishable by three criteria. First, the epidermal colonies, exhibiting extensive piling up of squames in the centers, were more stratified than esophageal colonies. Second, in sparse culture 70 to 90% of the esophageal cells but as few as 1 to 5% of the epidermal cells were competent in cross-linked envelope formation upon treatment with the ionophore X537A. After reaching confluence, up to 90% of the cells of both types formed envelopes upon ionophore treatment. Third, epidermal cells in suspension culture reached maximal levels of spontaneously cross-linked envelopes in 1 day or less, while esophageal cells required about 4 days in suspension to reach maximal levels. A reproducible finding with both cell types was that initial colony-forming efficiencies of less than 1% increased to about 40% upon serial passage with consequent derivation of continuous lines. Sparse cultures of esophageal cells with high colony-forming ability retained a high degree of envelope competence (70 to 90%), indicating these two properties are not mutually exclusive. The derived lines exhibited reduced dependence upon feeder layer support at clonal density, but in suspension culture the cells did not grow and lost colony-forming ability with a half-time of several hours. We conclude that cells from these keratinized rat epithelia exhibit intrinsic differences in culture and become continuous lines expressing characteristic regulation of envelope competence and loss of germinative capability in suspension.

Animals↗
PubMed1983

Development and characterization of a new murine renal tumor model. Chemotherapeutic results.

A murine renal cell carcinoma model, the RC tumor, was pharmacologically and histologically characterized and was used for the evaluation of 20 chemotherapeutic agents. This model, when implanted IP or SC showed reproducible behavior and was found to be very sensitive to many drugs with different mechanisms of action, and particularly to alkylating agents. The IP-implanted tumor was sensitive to some clinically active drugs which were reported inactive against L1210 or P388 murine leukemias. The highest sensitivity of this model than of L1210 and P388 leukemias makes the RC tumor a good prescreening system for testing potential chemotherapeutic agents.

Adenocarcinoma↗
PubMed1983

Polycyclic aromatic hydrocarbon toxicity and induction of metabolism in cultivated esophageal and epidermal keratinocytes.

Serially cultivated keratinocytes of human and rat epidermis and esophagus were compared with respect to their sensitivity to toxic effects of 3-methylcholanthrene and ability to metabolize benzo(a)pyrene. 3-Methylcholanthrene was highly toxic to the human keratinocytes and to early-passage rat epidermal keratinocytes, as evidenced by markedly reduced growth upon continuous exposure or reduced colony-forming ability after 1-day exposure to concentrations of 0.4 to 40 microM in the culture medium. Rat esophageal and late-passage rat epidermal cells appeared insensitive to 3-methylcholanthrene by these criteria. All the cell types except late-passage rat epidermal cells metabolized benzo(a)pyrene at comparable rates, and expressed aryl hydrocarbon hydroxylase maximally inducible by similar concentrations of 3-methylcholanthrene. Biotransformation in the human cells was greatly inhibited by alpha-naphthoflavone, a specific inhibitor of aryl hydrocarbon hydroxylase. The lack of toxicity of 3-methylcholanthrene toward late-passage rat epidermal cells can be attributed to the low constitutive rate of biotransformation these cells exhibit. The insensitivity of rat esophageal cells despite substantial metabolic activity reflects the importance of intrinsic differences among keratinocytes derived from different epithelia and species in determining toxic response. Human cervical and monkey esophageal keratinocyte cultures also actively metabolized benzo(a)pyrene, illustrating further the utility of the culture system for exploring differences among species and epithelial cell types.

Animals↗