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Biomedical subjects

R Tanzi

Publications and source records attributed to R Tanzi.

At least 37 records · Page 2Linked to original sources
PubMed1988

Trisomy 21 (Down syndrome): studying nondisjunction and meiotic recombination by using cytogenetic and molecular polymorphisms that span chromosome 21.

By combining molecular and cytogenetic techniques, we demonstrated the feasibility and desirability of a comprehensive approach to analysis of nondisjunction for chromosome 21. We analyzed the parental origin and stage of meiotic errors resulting in trisomy 21 in each of five families by successfully using cytogenetic heteromorphisms and DNA polymorphisms. The 16 DNA fragments used to detect polymorphisms spanned the length of the long arm and detected recombinational events on nondisjoined chromosomes in both maternal meiosis I and maternal meiosis II errors. The meiotic stage at which errors occurred was determined by sandwiching the centromere between cytogenetic heteromorphisms on 21p and an informative haplotype constructed using two polymorphic DNA probes that map to 21q just below the centromere. This study illustrates the necessity of combining cytogenetic polymorphisms on 21p with DNA polymorphisms spanning 21q to determine (1) the source and stage of meiotic errors that lead to trisomy 21 and (2) whether an association exists between nondisjunction and meiotic recombination.

Chromosome Banding↗
PubMed1987

Search for the familial Alzheimer's disease gene.

The application of molecular genetic techniques to the study of autosomal dominantly inherited Familial Alzheimer's Disease may provide a means to determine the chromosomal location of the defective gene causing this form of Alzheimer's disease. Knowledge of the chromosomal location of the defective gene will provide a basis for isolating and characterizing this gene. Preliminary investigations indicate that several candidate genes can be excluded as the site of the defect. Current data also indicate that the defective gene does not reside close to random DNA markers on the distal portion of chromosome 21. Additional DNA markers on the proximal portion of chromosome 21 long arm are currently being investigated.

Alzheimer Disease↗
PubMed1986

O-acylated sialic acid variants in mucinous tumours of the ovary.

O-acylated sialic acid variants (site 8) can be demonstrated histochemically by the PB/KOH/PAS method. They are secreted by goblet cells of the lower gastrointestinal tract, by colorectal adenocarcinomas, and by their metastases. Since the metastases are positive only when the primary tumour is positive, O-acylated sialomucins can be considered to be specific markers of colorectal adenocarcinomas if identified in metastases of a tumour of unknown origin. In our histochemical study we evaluated 29 mucinous cystomas of the ovary (23 benign and 6 malignant). We found that six cases were positive to PB/KOH/PAS. The positivity was observed in a limited number of cells and only in areas which presented an intestinal type epithelium. It was also more evident in malignant cystomas than in benign ones. We therefore think that the PB/KOH/PAS positivity can not only be considered a marker of colorectal adenocarcinomas, but also of all neoplasms which originate from an intestinal epithelium or appear to an "intestinal type epithelium".

Adenocarcinoma, Mucinous↗
PubMed1986

O-acetylated sialic acid variants in intestinal glandular metaplasia of the urinary tract.

Two cases of chronic cystitis, two of chronic ureteritis, one of chronic pyelitis and two transitional cell carcinomas of the urinary tract showed glandular metaplasia or focal mucin production. Positive staining for O-acetylated sialic acid variants (sites 7 and 8) detected by the PB-KOH-PAS method was found in the two cases of cystitis, in one of chronic ureteritis and in one of chronic pyelitis. Positive staining was observed only in areas showing an intestinal type of metaplasia and in which goblet cells and argyrophil cells were also identified. These findings taken together with earlier studies on ovarian cystadenomas lead the authors to believe that O-acetylated variants are markers of an intestinal type of epithelium. Evaluation of O-acetylated sialomucins may be useful in further studies on the histogenesis of primary adenocarcinomas of the bladder.

Adult↗
PubMed1986

Linkage analysis in a family with dominantly inherited torsion dystonia: exclusion of the pro-opiomelanocortin and glutamic acid decarboxylase genes and other chromosomal regions using DNA polymorphisms.

A search for the defective gene causing torsion dystonia has been carried out in a family manifesting an autosomal dominant mode of inheritance of this movement disorder. Complete neurologic examination and establishment of lymphoblast lines have been carried out for over 50 members. Linkage analysis, using cloned DNA sequences and restriction fragment length polymorphisms, was evaluated by the LOD score method with requisite assumptions for mode of inheritance, age-of-onset and incomplete gene penetrance. Genes for pro-opiomelanocortin and glutamic acid decarboxylase, which have been implicated in the etiology of the disease in rat models, were excluded as being responsible for the disease state in this family. Other regions of the genome were also excluded using DNA probes for other genes and random "unique" sequences.

Adolescent↗
PubMed1986

Immunohistochemical study of carcinoembryonic antigen, epithelial membrane antigen, and secretory immunoglobulin system in the large bowel adenoma-carcinoma sequence.

To identify parameters for the malignant potential of large bowel adenomas, we used the avidin-biotin-peroxidase complex (ABC) technique. Patterns of carcinoembryonic antigen, epithelial membrane antigen, IgAs, and secretory component in 31 tubular, tubulovillous, and villous adenomas with different grading of dysplasia (mild, moderate, severe) and with early cancer were studied. All markers showed different degrees of staining intensity and various cellular localizations. We found that these variations might be related to dysplasia grading. Adenoma size did not influence the marker patterns. IgAs seemed to be the more selective among the markers studied. Our results suggested a dysplasia-carcinoma sequence instead of an adenoma-carcinoma sequence concept.

Adenocarcinoma↗
PubMed1986

Patterns of mucous secretion in normal and pathological conditions of the endocervix.

20 specimens of normal endocervix, 30 of chronic cervicitis, 20 of endocervical polyps and 10 of adenocarcinomas were histochemically investigated in order to assess their mucin pattern. Diastase periodic acid-Schiff (D-PAS), Alcian blue pH 2.5 (AB), High iron-diamine (HID) and HID followed by Alcian blue pH 2.5 (HID-AB) were used. Both the superficial and glandular epithelium of the normal endocervix contained abundant amounts of neutral mucins. Generally sialomucins were scarce and predominant over sulphomucins: the latter were in some cases absent in the proliferative phase of the menstrual cycle and increased in the secretory phase. In chronic cervicitis a slight amount of sulphomucins in the residual glandular epithelium, especially in areas presenting severe inflammation, pseudoerosion, or both was observed. Nabothian cysts mainly contained sulphomucins. In the endocervical polyps, the mucin pattern was various. In adenocarcinomas mucin secretion was usually scanty and mixed with a predominance of sialomucins. Therefore resulted: the mucin pattern of the normal endocervical epithelium is related to the menstrual cycle; the histochemical evaluation of mucous secretion, presently doesn't seem to be helpful in differentiating endocervical from endometrial adenocarcinomas.

Adenocarcinoma↗
PubMed1985

Primary signet-ring carcinoma of the large bowel. Report of nine cases.

Nine cases of signet-ring carcinoma have been observed from among 800 consecutive histologic cases diagnosed as adenocarcinoma of the colon during a period of 10 years (0.9%). This group of nine patients (Group A) has been matched for sex, age, and stage with a group of 45 patients affected by ordinary carcinoma of the colon (Group B). Clinical and histologic parameters, including symptoms, primary tumor site, free interval from primary surgery, histochemical investigation of intracytoplasmic mucins, and survival, were evaluated. The results of this investigation showed no clinical differences between signet-ring carcinoma and ordinary carcinoma, and no statistically significant results were observed regarding the frequency of local recurrence and actuarial survival.

Adenocarcinoma, Mucinous↗
PubMedDate not supplied

A morphometric study of cystadenolymphoma (Warthin's tumor).

This work is concerned with a morphometric analysis of cystadenolymphoma (CAL, Warthin's tumor), a growth generally found in the parotid gland. CAL is composed of various amounts of epithelium-lined cysts and of lymphoid stroma. Our results support the notion that the epithelium is the proliferating component in CAL. They also challenge the idea that CAL is a tumor, because its growth is slow and self-limiting, and occurs in a restricted space.

Adenolymphoma↗