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Biomedical subjects

M Messina

Publications and source records attributed to M Messina.

At least 19 recordsLinked to original sources
PubMed1999

[Vascular calcification after kidney transplantation. Preliminary results].

BACKGROUND: Vascular calcifications (VC) are a common feature in chronic dialysis patients, but their clinical significance is debated, and the role of kidney transplantation (TRP) in the natural history of their development has received only scanty attention. METHODS: In our study we reviewed skeletal surveys as well as clinical and biochemical records of 13 patients who started again chronic dialysis at our Centre after failure of their kidney grafts. Changes of VC (during TRP) were scored as: 1 = no substantial progression (4 patients), 2 = moderate worsening (4 patients), 3 = severe worsening (5 patients = 38.4%). RESULTS: The most interesting association with the clinical/biochemical parameters seems to be between the score 3 subgroup and highest Ca*P values and vitamin D therapy. Four out of five score 3 patients experienced overt vascular events and 4 out of 5 of the same subgroup experienced parathyroidectomy (PTX) before, during or after the TRP. CONCLUSIONS: In this preliminary study we can conclude that a) the possibility of dramatic worsening of VC during TRP is not a rare event and this feature has a strong clinical implication, b) PTX before TRP could remove at least one of the putative risk factors in patients waiting for TRP with suboptimal control with medical therapy.

Adolescent↗
PubMed1998

Influence of structural properties and kinetic constraints on Bacillus cereus growth.

The influence of structural properties and kinetic constraints on the behavior of Bacillus cereus was investigated on agar media. Dimensional criteria were used to study the growth in bacterial colonies. The architecture of the agar gel as modified by the agar content was found to influence the colony size, and smaller colonies were observed on media containing 50 to 70 g of agar liter-1. Except at low nutrient levels, colonies responded to nutrient gradients by decreasing in size the farther away they were from the nutrient source, and the decrease in colony size was influenced by the agar content. The diffusivities of glucose and a protein (insulin-like growth factor) were not affected by the gel architecture, suggesting that other factors, such as mechanical factors, could influence microbial growth in the agar systems used. Increasing the viscosity of the liquid phase of the agar media by adding polyvinylpyrrolidone resulted in a reduction in colony size. When the agar concentration was increased, the colony areas were not influenced by the viscosity of the system.

Agar↗
PubMed1998

RET/PTC and RET tyrosine kinase expression in adult papillary thyroid carcinomas.

The prevalence of RET/PTC rearrangements in papillary thyroid carcinomas (PTCs) varies widely in different studies, and an association of RET/PTC presence with tumor behavior remains to be clarified. A prospective study of 50 adult PTCs examined, using RT-PCR, the prevalence of the 3 main RET rearrangements and also of RET tyrosine kinase (TK) domain sequence expression. The genetic findings were correlated with the MACIS clinical prognostic score and with individual clinical parameters. Three of the patients had been exposed to radiation in childhood or adolescence. Four of the PTCs contained RET/PTC1, confirmed by sequencing, and none contained RET/PTC2 or RET/PTC3. The prevalence of RET rearrangements overall was 8%, but in the subgroup of 3 radiation-exposed patients it was 66.6%. Interestingly, RET tyrosine kinase domain messenger ribonucleic acid was detectable in 70% of PTCs using RET exon 12/13 primers and was detectable in 24% of PTCs using RET exon 15/17 primers. RT-PCR for calcitonin and RET extracellular domain, however, was negative. There was no association between the presence or absence of RET/PTC in the patient's tumor and clinical parameters. We conclude that RET/PTC1 is the predominant rearrangement in PTCs from adults with a history of external irradiation in childhood. RET TK messenger ribonucleic acid expression is common in PTCs, using RT-PCR, and cannot be used to infer the presence of specific RET rearrangements or of RET activation.

Adult↗
PubMed1997

Intrauterine volvulus without malrotation in a very low-birth-weight preterm infant.

Midgut volvulus without abnormalities of intestinal rotation/fixation is an extremely rare cause of acute intestinal obstruction in the neonatal period with a high morbidity and mortality. The authors describe an intrauterine volvulus without malrotation in a 970g preterm girl born at 27 weeks' gestation. The discrepancy between minimally evocatory clinical manifestations and severity of intestinal pathology is underscored. Resection of the necrotic bowel and primary end-to-end anastomosis within 30 hours of birth was followed by a favorable outcome. A literature review indicates a significant relation of intrauterine midgut volvulus without malrotation to preterm birth with low-birth-weight, immediate postnatal presentation and favorable prognosis.

Adult↗
PubMed1997

Expression of Toxoplasma gondii genes in the closely-related apicomplexan parasite Neospora caninum.

We have established the feasibility of using Neospora caninum as a heterologous system for the expression of genes from the closely-related parasite Toxoplasma gondii. Plasmid construct containing the lacZ gene from Escherichia coli driven by T. gondii promoters were electroporated into N. caninum parasites, and expression of beta-galactosidase (beta-Gal) activity was assayed enzymatically. In transient assays, expression of beta-Gal driven by the GRA1 promoter was approximately 10-fold higher than the expression obtained with the SAG1 promoter. Enzyme activity was not detected when N. caninum parasites were transfected with a promoterless lacZ construct. Transfection of N. caninum with complete genomic clones of SAG1 or GRA2 from T. gondii yielded parasites that transiently expressed the respective gene products, as detected by immunofluorescence and Western blot. Additionally, these transiently expressed T. gondii proteins appeared by immunofluorescence localization and Triton X-114 partitioning to be correctly targeted in both extracellular and intracellular N. caninum parasites. Heterologous gene expression should be useful for studying the function of specific gene products and may facilitate the identification of genes responsible for the phenotypic differences observed between these two closely-related apicomplexan parasites.

Animals↗
PubMed1997

Villous adenoma of the bladder.

Villous adenomas of the bladder are rare tumors and up to now they have not been seen to undergo malignant transformation. We report a case of villous adenoma of the bladder with areas of adenocarcinoma in a 72-year-old man. We describe all the morphological, histochemical and immunohistochemical features characterizing this tumor. We recommend adequate pathological sampling and a thorough follow-up of patients with villous adenoma. The prognosis and the behaviour of these adenomatous papillary lesions, morphologically similar to colonic adenomas, in the bladder is unclear. We report a case with focal area of adenocarcinoma and review the literature.

Adenocarcinoma↗
PubMed1996

Renal transplantation in a case of mannosidosis.

Mannosidosis is an inherited autosomal recessive mucopolysaccharidosis. Patients affected accumulate mannose-rich compounds in various tissues and excrete an increased quantity of oligosaccharides with mannose as a component. A case of type II mannosidosis with end-stage renal failure is reported. The patient, after 6 years of regular hemodialysis treatment, received a kidney transplant. At the time this article was written, the graft was functioning well and thesaurismotic renal deposits had not been observed. The clinical course of mannosidosis was silent and the patient's quality of life was good. Although the risk of recurrence could not be excluded, it seems that renal transplantation can be safely offered to patients affected with mannosidosis type II, in the rare setting of chronic renal failure.

Adult↗
PubMed1996

Nutritional implications of dietary phytochemicals.

Although increasing the levels of phytochemicals in foods via traditional breeding or genetic engineering would appear to pose less of a risk, there is still the possibility of over consumption given the ease with which phytochemical content can be increased. According to the recent position paper by the American Dietetic Association on phytochemicals, "the dietetics professional ... is the specialist who should make recommendations concerning appropriate dietary intake to optimize the potential benefits of phytochemical-rich or functional foods in overall health." For dietitians to make these recommendations, it will be necessary for the nutrition community to make a concerted effort to incorporate information on phytochemicals into nutrition manuals and professional resources. As it is, most of the research and discussion of phytochemicals is conducted by professionals not related or only peripherally related to the field of nutrition. This is truly an exciting time to be involved in the nutrition field. We have moved a head from thinking that only a relatively small number of dietary factors possess biological activity to recognizing that there are hundreds and perhaps thousands of such factors. It will be many years before our understanding of phytochemicals approaches our knowledge of vitamins and minerals- and it is worth nothing that our knowledge of vitamins and minerals is still incomplete. But it does appear that the phytochemicals help explain why plant-based diets, in general, are associated with a reduced risk of many chronic diseases. And in fact, his may be the most important outcome from use of phytochemicals. The nutrition community now has more reasons for encouraging consumers to eat plant-based diets.

Attitude of Health Personnel↗
PubMed1995

Stable DNA transformation of Toxoplasma gondii using phleomycin selection.

Toxoplasma gondii (Tg) is an obligate intracellular protozoan parasite that is an important opportunistic pathogen in humans. To provide additional tools for molecular genetic analysis, we have developed a set of vectors for DNA transformation in Tg based on selection with the antibiotic phleomycin (Ph). These new vectors rely on the flanking sequences from the parasite genes GRA1, GRA2 or SAG1 to drive expression of the Tn5 ble gene encoding resistance to the DNA intercalating drug Ph (PhR). Treatment of extracellular parasites was used to select stable PhR transformants by plaque formation on host cell monolayers. Transfection of linear or circular forms of the pGRA1/ble, pGRA2/ble or pSAG1/ble vectors by electroporation resulted in stable transformation with an efficiency of approx. 10(-4)/micrograms DNA. Stable transformants contained 1-5 copies of ble that were integrated at non-homologous sites in the parasite nuclear genome. Ble provides a new dominant selectable marker for safe, efficient and rapid isolation of stable DNA transformants in Tg.

Acetyltransferases↗