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Biomedical subjects

Y Ziv

Publications and source records attributed to Y Ziv.

At least 73 records · Page 4Linked to original sources
PubMed1990

Genetic mapping of X-linked albinism-deafness syndrome (ADFN) to Xq26.3-q27.I.

X-linked albinism-deafness syndrome (ADFN) was described in one Israeli Jewish family and is characterized by congenital nerve deafness and piebaldness. The ADFN mutation probably affects the migration of neural crest-derived precursors of the melanocytes. As a first step toward identifying the ADFN gene, a linkage study was performed to localize the disease locus on the X chromosome. The family was found to be informative for 11 of 107 RFLPs along the X, and two-point analysis showed four of them--factor 9 (F9), DXS91, DXS37, and DNF1--to have definite or suggestive linkage with ADFN. Multipoint linkage analysis indicated two possible orders within this cluster of loci, neither of which was preferable. In both orders F9 was the most distal, and the best estimate for the location of ADFN was between F9 and the next proximal marker (8.6 cM from F9 [Z = 8.1] or 8.3 cM from F9 [Z = 7.9]). These results suggest that the ADFN is at Xq26.3-q27.1. Disagreement between our data and previous localization of DXS91 at Xq11-q13 was resolved by hybridization of the probe pXG-17, which detects the DXS91 locus, to a panel of somatic cell hybrids containing different portions of the X chromosome. This experiment showed that this locus is definitely at Xq24-q26. Together with the linkage data, our results place DXS91 at Xq26 and underscore the importance of using more than one mapping method for the localization of molecular probes.

Albinism↗
PubMed1989

Cellular and molecular characteristics of an immortalized ataxia-telangiectasia (group AB) cell line.

Ataxia-telangiectasia (A-T) is a multisystem hereditary disease featuring neurodegeneration, immunodeficiency, extreme cancer proneness, chromosomal instability, and radiosensitivity. A-T is found in many ethnic groups, and is genetically heterogeneous: four complementation groups have been identified in A-T so far. Attempts to isolate the A-T gene are based in part on gene transfer experiments, using permanent A-T fibroblast lines, obtained by transformation with SV40. "Immortalization" of A-T primary diploid fibroblasts using SV40 is difficult, possibly because of the chromosomal instability of these cells. The number of currently available permanent A-T fibroblast lines is small, and not all of them have been assigned to specific complementation groups. Using the assay of X-ray induced inhibition of DNA synthesis, we have assigned the A-T strain AT22IJE to complementation group AB. Origin-defective SV40 was used to transfect these cells, and one transformant (AT22IJE-T), which survived crisis, was found to have the typical characteristics of permanent cell lines obtained in this way. "In-gel renaturation" analysis did not show any DNA amplification of high degree in AT22IJE-T. Cytogenetic analysis showed considerable chromosomal instability in the new cell line, and medium conditioned by these cells contained the clastogenic activity which is characteristic of the parental strain as well. Other parameters of the "cellular A-T phenotype" have also been retained in the immortalized cells: hypersensitivity to the lethal effects of X-rays and neocarzinostatin, as well as "radioresistant" DNA synthesis. However, the sensitivity of AT22IJE-T to both DNA-damaging agents is less pronounced than that of the parental cells. The capacity of the cells for uptake of foreign DNA was tested by introducing into them the plasmid pRSVneo, using three different transfection methods. Satisfactory frequency of G418-resistant transfectants (0.66%) was achieved using a protocol recently published by Chen and Okayama (Mol. Cell Biol., 7: 2745-2752, 1987), which was found to be superior to the traditional calcium phosphate transfection method and to the polybrene-based method.

Ataxia Telangiectasia↗
PubMed1989

G2 chromosomal radiosensitivity in families with ataxia-telangiectasia.

Ataxia-telangiectasia (A-T) is an autosomal recessive disease involving chromosomal instability, susceptibility to cancer and X-ray hypersensitivity. The latter two features are expressed to a limited extent in the heterozygous carriers of A-T mutations. Although fibroblast lines from A-T heterozygotes clearly show increased susceptibility to the lethal effect of X-irradiation, the difference in post-irradiation survival between cell lines and normal controls is not always large enough to allow the use of X-ray sensitivity as a laboratory assay for carrier detection in A-T. Recently, we have shown in a blind study, that the extent of chromatid damage induced in the G2 phase of the cell cycle by moderate doses of X-rays is markedly higher in A-T heterozygous cells than in normal controls. We have now applied this test to 6 additional obligatory heterozygotes and 24 individuals with different risks of being A-T carriers, from three Israeli A-T families. All 6 cell lines from the obligatory heterozygotes showed the typical hypersensitivity to the clastogenic action of X-rays in G2; of the 24 cell lines with unknown A-T genotype, 16 showed the same hypersensitivity, and 8 responded in a normal way. The proportion of cell lines showing the "A-T-heterozygous phenotype" was in accord with the expected value, based on Mendelian chance calculations. Since these observations were made, a daughter of two hypersensitive parents in one of these families has been diagnosed as having A-T. This confirmed the presumed A-T heterozygosity of the parents, as indicated by the laboratory assay.

Ataxia Telangiectasia↗
PubMed1989

Ataxia-telangiectasia: a variant with altered in vitro phenotype of fibroblast cells.

The clinical and cellular phenotype of ataxia telangiectasia (AT) has been extensively documented in numerous patients of different ethnic groups and is characterized by several specific laboratory hallmarks, such as chromosomal instability, profound radiosensitivity and radioresistant DNA synthesis. Several recent reports have, however, shown variations on this theme. This article describes 2 Turkish siblings with AT, who showed a typical but somewhat more prolonged clinical course of the disease and altered characteristics of fibroblast cells, compared to the 'classical' AT cellular phenotype. Fibroblast strains derived from these patients showed a normal cellular life span, moderate degrees of chromosomal instability and sensitivity to the lethal effects of X-rays and neocarzinostatin, and lack of radioresistant DNA synthesis. A compilation of the literature on 'AT variants' and 'AT-like' syndromes shows that in addition to the internal variability of AT, this disease occupies a limited segment within a large spectrum of clinical and cellular features, which are common to a variety of syndromes. Each of these syndromes covers a different segment in this spectrum. The genetic basis of this family of disorders might be complex.

Ataxia Telangiectasia↗
PubMed1989

Segmental portal hypertension and polycythemia vera.

A patient known to have polycythemia vera developed recurrent melena and was found to have bleeding gastroesophageal varices. Selective superior mesenteric angiography suggested splenic vein thrombosis. Splenectomy led to the disappearance of the varices with no subsequent recurrence of bleeding. We believe this to be the first fully described case of polycythemia vera associated with segmental portal hypertension, and propose that polycythemia vera patients may develop "silent" segmental portal hypertension and that this should be taken into consideration when treating them.

Humans↗
PubMed1989

Clinical implications of anatomic variations of the splenic artery.

An aberrant course of the proximal splenic artery was observed in nine of 26 adult cadavers dissected for mapping of the lesser omentum. Such an aberrant course makes the artery vulnerable to iatrogenic injury. In view of this relatively high prevalence of splenic artery aberration, it is suggested that surgeons operating in the area of the lesser omentum should keep in mind the possibility of its occurrence and the dangers that it may present.

Adult↗
PubMed1988

Local recurrence after low anterior resection using the EEA stapling device.

Fifty-five patients underwent curative stapled low anterior resection for rectal adenocarcinomas located 5 to 15 cm from the anal verge. Two patients (3.7 percent) died postoperatively. The mean follow-up for the remaining 53 patients was 40 months. Local recurrence was diagnosed in 17 patients (32 percent), in most (88 percent) within the first two years after surgery. Most local recurrences appeared in patients classified as Dukes' C1 and C2 but, surprisingly, no significant difference was found between rectal tumors of high and low location as regards recurrence. The high rate of recurrence in this series may be attributable to the large number of patients with advanced tumors, and poorly differentiated carcinoma, or both.

Adenocarcinoma↗
PubMed1988

The immunologic profile of anesthetists.

Reports in the literature have suggested possible impairment of immunocompetence in operating theater personnel. In a group of 18 physician anesthesiologists the following were determined: hemoglobin concentration; white blood cell count; numbers of T, B, and natural killer (NK) lymphocytes; number of T-active cells; and numbers of T-helper/inducer (Th) and T-suppressor/cytotoxic (Ts) cells; and the Th/Ts ratio. Function of T lymphocytes was evaluated using the local xenogeneic graft-versus-host reaction and spontaneous suppressor or helper activity of T cells. The same parameters were determined in a group of 18 age- and sex-matched healthy controls. It was found that no matter what their age or how long they have been engaged in anesthetic practice, anesthetists show no immunosuppression as evidenced by these parameters.

Adult↗
PubMed1988

Neutropenic enterocolitis. Case report.

Early recognition and adequate treatment of neutropenic enterocolitis, a life-threatening complication of aggressive chemotherapy for leukemia, lymphoma or other malignancy, may offer a favorable outcome. Three cases are presented, including the first reported occurrence in a child with osteogenic sarcoma. Two patients were treated surgically and the third conservatively.

Adult↗
PubMed1987

Congenital segmental dilatation of small intestine with oesophageal atresia and duodenal atresia in a premature infant.

In a premature infant documented to have oesophageal atresia laparotomy revealed the additional findings of segmental dilatation of the small intestine as well as duodenal atresia, the coincidental occurrence of which is extremely rare. Resection of the dilated segment was performed with end-to-end one-layer anastomosis and side-to-side duodeno-duodenostomy and a feeding gastrostomy was created. Three months later end-to-end oesophago-oesophagostomy was successfully performed via a right thoracotomy. During the 8 years since then the child's growth and development have been normal.

Dilatation, Pathologic↗
PubMed1987

Acute inflammation and distension of the gall bladder in infancy.

Acute cholecystitis in children is a rare disease which has been associated with haemolytic anaemias, intercurrent illness and congenital anomalies. Acute inflammation and distension of the gall bladder in infancy is very rare and the underlying cause is usually not identified. This study describes two infants presenting with acute acalculous cholecystitis with marked distension of the gall bladder. It is stressed that this entity must be taken into account in the differential diagnosis when there is a palpable mass and/or tenderness in the right abdomen, particularly in the presence of intercurrent illness. Early operation is recommended and cholecystectomy is the preferred procedure.

Acute Disease↗
PubMed1987

Acute cholecystitis complicating unrelated disease: etiological considerations.

The phenomenon of acute cholecystitis complicating an unrelated operation has been reported with increasing frequency, and may be preceded by a variety of operative procedures and a lack of previous biliary tract symptoms. Among eight such patients treated by us, seven developed acute cholecystitis postoperatively, and in one it was discovered during operation for bleeding duodenal ulcer. Two patients had undergone wide excision of the breast; two, highly selective vagotomy; one, nephrolithotomy; one, truncal vagotomy and gastroenterostomy; and one, left hemicolectomy and colostomy. In three patients, urgent cholecystectomy was performed, and four were treated conservatively with subsequent elective cholecystectomy. Histopathological studies revealed acute and chronic cholecystitis in all eight patients and cholelithiasis in four. One patient died in septic shock. Numerous contributing factors have been suggested, including hypovolemia and biliary stasis, as well as the presence of stones. It would appear that chronic cholecystitis or other biliary pathology, as found in our eight patients, is a major factor in the development of this manifestation.

Acute Disease↗
PubMed1986

Primary hyperparathyroidism in children.

We present here a series of seven children with primary hyperparathyroidism caused by parathyroid adenoma. Chief cells were the primary element in six patients and water-clear cells in one patient. A brief review of the literature on primary hyperparathyroidism in children is included. Emphasis is placed on the clinical characteristics of this rare disease in children.

Adenoma↗
PubMed1986

Preduodenal portal vein with situs inversus and duodenal atresia.

In a 7-day-old infant referred because of bile-stained vomiting, jaundice and lack of meconium, radiological examination revealed the 'double-bubble' sign of duodenal atresia as well as dextrocardia. This infant also had a strawberry haemangioma on the right shoulder. Operation disclosed situs inversus and a preduodenal portal vein as well as duodenal atresia. A side-to-side duodeno-jejunostomy was performed successfully without damage to the anomalous vein. The history of polyhydramnion during gestation, the presence of other anomalies, the rapid onset of bile-stained vomiting and the classic 'double-bubble' sign, together appeared to indicate that the duodenal atresia was intrinsic and not due to the external pressure of the anomalous vein on the duodenum.

Dextrocardia↗