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Biomedical subjects

R Rizzi

Publications and source records attributed to R Rizzi.

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

Determination of lineage and clonality in diffuse lymphomas using the polymerase chain reaction technique.

Malignant lymphomas of the diffuse mixed or diffuse large cell subtype are immunologically heterogeneous and morphologic features do not allow prediction of lineage. Applications of immunophenotypic and gene rearrangement techniques has greatly improved our ability to determine clonality and lineage. Nevertheless, some diffuse lymphomas are composed of numerous reactive cells accompanying a small clonal population, thereby making determination of clonality difficult, even with gene rearrangement techniques. In this study, we report two malignant lymphomas in which immunophenotypic and genotypic studies failed to elucidate evidence of clonality. In both cases, the polymerase chain reaction amplified segments of DNA containing the bcl-2/JH sequence, providing evidence of clonality and suggesting B-cell lineage. We conclude that the polymerase chain reaction technique may be useful in the diagnosis of some diffuse mixed and large cell lymphomas.

Adult↗
PubMed1991

Study of reproductive function in persons occupationally exposed to 2,4-dichlorophenoxyacetic acid (2,4-D).

We studied the reproductive function of 32 male farm sprayers who were exposed to 2,4-D. Sperm analysis was made after 4 days of sexual inactivity. Parameters analyzed were volume, sperm count, mobility and morphology. Exposure level was estimated by measuring the concentration of 2,4-D in the urine. Significant levels of asthenospermia, necrospermia and teratospermia were found in exposed workers compared with unexposed controls. Over time, asthenospermia and necrospermia diminished but the abnormal spermatozoa (teratospermia) continued.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1991

In vitro genotoxicity of dimethyl terephthalate.

Dimethyl terephthalate (DMTP), the para configuration of dimethyl phthalate, is one of the basic monomers used in the synthesis of polyethylene terephthalate (PET) plastics. Human exposure to DMTP may primarily occur during the manufacture of PET fibers and films. The mutagenic potential of dimethyl terephthalate was evaluated using a battery of in vitro short-term tests: the Ames test; DNA single-strand break assays in CO60 cells and in primary rat hepatocytes; UDS in HeLa cells; chromosome aberration and micronucleus assays in human peripheral blood lymphocytes; selective DNA amplification in CO60 and in Syrian hamster embryo cells. The results of this battery of in vitro assays clearly show that DMTP is nongenotoxic. By contrast, other authors have found DMTP to be an in vivo clastogenic compound and suggested that the mechanisms involved in these in vivo effects seem to have nothing in common with genotoxicity and are still unknown.

Adult↗
PubMed1991

Clinical spectrum of accidental hemlock poisoning: neurotoxic manifestations, rhabdomyolysis and acute tubular necrosis.

In the past, hemlock poisoning was only known for its neurotoxic effects; quite recently non-neurological features, consisting of rhabdomyolysis and acute renal failure, have been also described. Here we report our experience with these clinical findings, which we frequently observe in accidental hemlock poisoning. Between 1972 and 1990 we studied 18 patients: 17 of them were poisoned by conline (an alkaloid of Conium maculatim) in Apulia (Italy), and one by cicutoxin (the active principle of water hemlock) in New Mexico (USA). In the non-rapidly-fatal cases we tested myoglobinuria, serum muscle enzymes, and renal function. In the patients with acute renal failure we performed microscopical examination of kidney specimens; immunohistochemistry was carried out to identify myoglobin and actin in tubules. Coniine was detected in urine, serum, or tissues. Neurological features were present in all of our cases: coniine had a curare-like effect on the neuromuscular junction, whereas cicutoxin was convulsant on the central nervous system. In addition rhabdomyolysis was noted in the 17 subjects poisoned by coniine. Acute renal failure was observed in five patients; it was confirmed by histological evidence of tubular necrosis with intratubular deposition of myoglobin and actin released by rhabdomyolysis. Our cases seem to be the first with histopathologically proven acute tubular necrosis in coniine intoxication. In conclusion, in hemlock poisoning neurotoxic manifestations may be accompanied by rhabdomyolysis and acute tubular necrosis; increased awareness of these clinical features is recommended in order to improve the diagnostic and therapeutic procedure.

Adult↗
PubMed1990

Malignant lymphoma involving a Warthin's tumor: a case with immunophenotypic and gene rearrangement analysis.

We describe a Warthin's tumor which was involved by malignant lymphoma. The lymphoma was classified in the Working Formulation as follicular and diffuse, mixed small cleaved and large cell type. Frozen section immunohistochemical studies revealed an abnormal immunophenotype: immunoglobulin-negative and B-lineage. Gene rearrangement analysis confirmed the diagnosis by demonstrating rearrangements of both the immunoglobulin heavy and kappa light chain genes. The bcl-2 gene was also rearranged, consistent with the presence of the t(14;18) (q32;q21) translocation which is typically seen in follicular lymphomas. The T-cell receptor beta chain gene retained the germline configuration. The results in this case highlight an advantage of molecular techniques as compared with immunophenotypic analysis: gene expression is not required to demonstrate clonality.

Adenolymphoma↗
PubMed1990

[The prevention of bacterial endocarditis].

The paper examines the prevention of bacterial endocarditis in risk patients undergoing outpatient treatment. The hypothesis of possible bacteremia provoked by either diagnostic or therapeutic surgery should be carefully assessed. For this purpose antibiotic prophylaxis should be commenced, using different methods and doses according to the type of patient, in association with hygienic and behavioural norms which the specialist will recommend and monitor.

Anti-Bacterial Agents↗
PubMed1989

Antibodies to glutaraldehyde-polymerized human albumin (anti-pHSA) in viral hepatitis.

The antibody to polymerized human albumin (anti-pHSA) was studied in normal subjects and in the course of infection from hepatitis A virus, hepatitis B virus, and hepatitis non-A, non-B virus. Results show that anti-pHSA antibody was never found in normal subjects, but it appeared during virus liver pathologies. The behavior of anti-pHSA differs in acute type A hepatitis that does not change to chronic form and in those forms which tend to become chronic (B and nonA, nonB). In the type-A infection anti-pHSA disappears after the acute phase; in the other two forms it persists all along as the infection develops. Specifically in non-A, non-B infection only the IgM type anti-pHSA is produced.

Acute Disease↗
PubMed1989

Malformation syndrome with t(2;22) in a cancer family with chromosome instability.

A de novo unbalanced t(2;22)(q37;q11.2) [corrected], resulting in the deletion of the 22pter-q11 and 2q37-qter regions, was observed in a 12-year-old girl born with a congenital malformation syndrome and later displaying signs of neurologic impairment. Some of the clinical signs observed appear to overlap those found in subjects monosomic in the 22q11 region affected by the DiGeorge syndrome. The chromosomal rearrangement observed may be related to a familial cytogenetic instability that also gives rise to sustained cancer predisposition.

Abnormalities, Multiple↗
PubMed1989

Factors affecting calving interval in Italian Holstein-Friesian heifers.

Effect of rump conformation on calving interval of 520 Italian Holstein Friesian heifers was evaluated with simultaneous adjustment for herd, year of birth, calving month, age at first parturition, and milk production. All factors, except age at first parturition, were important sources of variation. Heifers with narrow rumps at the pins had the longest calving interval. There were significant differences among the herds. Cows born between 1979 and 1981 had shorter calving intervals, probably resulting from a national plan against bovine infertility initiated in 1981. Cows calving in July had better reproductive performance. There was positive relationship between milk production and calving interval.

Age Factors↗
PubMed1988

Variability of reduced glutathione levels in Massese ewes and its effect on daily milk production.

The variability of the erythrocyte concentration of the tripeptide glutathione was studied in four flocks of Massese sheep. A relationship was found between glutathione level and stage of lactation in which the second month showed the lowest content. Genotype at transferrin and haemoglobin loci was associated with glutathione levels. Homozygotes at the transferrin locus yielded higher levels, while the D allele at the same locus was associated with lower concentrations. Animals with haemoglobin AA showed higher contents of glutathione. Also, a negative correlation was found between daily milk production and glutathione level.

Animals↗
PubMed1988

Investigation of the long-term effects of unilateral hearing loss in adults.

The recent audiological literature has put forward the hypothesis that children with unilateral hearing loss (UHL) show delays in educational achievement and academic progress and some behavioural difficulties. This motivated us to investigate the long-term effects of monaural auditory deprivation in a group of adults who had suffered from UHL since childhood. A group of subjects, ranging in age from 30 to 55 years, suffering from sensorineural UHL since early childhood, has been examined for psychosocial and psychoacoustical effects and statistically compared with a control group matched for age and sex. We prepared a questionnaire directed to provide some objective and subjective indices of psychosocial disability and handicap. Some questions were directed towards specific aspects of auditory function; others assessed the degree of education and the type of working performed. The results of the investigation confirmed the superiority of binaural v. monaural hearing. This was clearly demonstrated in psycho-acoustical performance in sound localisation, speech recognition in noise, together with the appreciation of music. On the other hand, the parameters concerned with educational, social and employment achievement did not support the existence of any significant difference between binaurally and monaurally hearing subjects. The data obtained in the present study thus do not support the existence of non-auditory, long-term effects of monaural hearing loss.

Achievement↗
PubMed1988

Impaired growth hormone secretion in neonatal hypothyroid rats: hypothalamic versus pituitary component.

In 10-day-old rats made hypothyroid by giving dams propylthiouracil (PTU) in the drinking water since the day of parturition, simultaneous radioimmunoassay (RIA) determinations of basal and stimulated growth hormone (GH) secretion, hypothalamic GH-releasing hormone (GHRH)-like immunoreactivity (LI) content, immunocytochemical localization of somatotrophs, and hypothalamic GHRH-LI-positive structures were performed. The frequency of somatotrophs was also determined. One-day-old hypothyroid rats, whose mothers had been given PTU since the 14th day of pregnancy, were also used for comparison. In 10-day-old hypothyroid rats, pituitary and plasma GH levels and the number of somatotrophs were considerably lower and plasma TSH levels were significantly higher than those in age-matched control rats; however, GHRH-LI titers in the mediobasal hypothalamus and the morphology of GHRH-LI-positive structures were unaltered. In 1-day-old rats the only alteration present, in addition to elevated plasma TSH levels, was a clear-cut decrease in plasma GH levels. An acute challenge with GHRH (20 ng/100 g body wt, sc) or clonidine (15 micrograms/100 g body wt, sc) induced a clear-cut rise in plasma GH levels 15 min postinjection in 10-day-old control rats but failed to do so in age-matched hypothyroid rats. Both compounds failed to rise plasma GH in both hypothyroid and control 1-day-old rats. Taken together these data indicate that in neonatal and infant rats deprivation of thyroid hormones acts primarily to depress pituitary somatotroph function and that possible changes in GHRH-secreting structures represent a later postnatal event.

Animals↗
PubMed1987

Cytogenetic instability in a family with gastric cancer recurrence.

An index case with a congenital malformation syndrome enabled detection of a family that had a previous history of spontaneous abortuses and recurrence of neoplasia through three generations. Cytogenetic analysis performed on lymphocytes from 11 subjects in the second and third generation showed karyotypic alterations in both tumor bearers and apparently normal subjects. Chromosome variations consisted of: spontaneous chromosome fragility; chromosome translocations; polymorphisms in the heterochromatic regions in chromosomes Y, #1, #16, #22. The inheritance pattern of all chromosome rearrangements and heteromorphisms observed was established starting with the second generation, and the contribution of specific individuals was identified. Although the relationship between chromosomal instability and predisposition to gastric cancer does not appear to be coincidental, no specific chromosome alteration in normal somatic cells was shared by all members of the family who developed or are at risk of developing tumors.

Adult↗
PubMed1986

Chronic hepatitis in HBsAg carriers with serum HBV-DNA and anti-HBe.

We compared the clinical and serologic features of 118 hepatitis B surface antigen carriers with hepatitis B e antibody (anti-HBe) followed up for 3-10 yr (mean 6.1 yr), separated according to the presence or absence of hepatitis B virus-deoxyribonucleic acid (HBV-DNA) in serum. The test was performed by molecular hybridization. There were 28 carriers with and 90 without viral DNA. Carriers with serum anti-HBe/HBV-DNA had major liver disease; cirrhosis developed during the follow-up period in 9 of the patients. All had the hepatitis B "core" antigen in the liver, localized prevalently in the cytoplasm of the hepatocytes. Among carriers of anti-HBe alone, 73 had persistently normal tests of liver function and 17 had abnormal levels of alanine transaminase and usually minor forms of liver damage at histology. In a group of 24 carriers of hepatitis B e antigen who spontaneously seroconverted to anti-HBe, hepatitis and a prevalent nuclear distribution of intrahepatic hepatitis B core antigen were found in temporal correlation with the presence of hepatitis B e antigen in serum. The replication of the hepatitis B virion terminated and liver disease remitted after seroconversion to anti-HBe. A positive HBV-DNA test in anti-HBe carriers is associated with a severe and evolutive liver disease and may provide an indication for treatment with drugs inhibiting the synthesis of HBV-DNA.

Adolescent↗