Impaired taste sensation in type 2 diabetic patients without chronic complications: a case-control study.

PURPOSE: Few and contradictory data suggest changes in taste perception in type 2 diabetes (T2DM), potentially altering food choices. We, therefore, analyzed taste recognition thresholds in T2DM patients with good metabolic control and free of conditions potentially impacting on taste, compared with age-, body mass index-, and sex-matched normoglycemic controls. METHODS: An ascending-concentration method was used, employing sucrose (sweet), sodium chloride (salty), citric acid (sour), and quinine hydrochloride (bitter), diluted in increasing concentration solutions. The recognition threshold was the lowest concentration of correct taste identification. RESULTS: The recognition thresholds for the four tastes were higher in T2DM patients. In a multiple regression model, T2DM [ß = 0.95; 95% CI 0.32-1.58; p = 0.004 (salty); ß = 0.61; 0.19-1.03; p = 0.006 (sweet); ß = 0.78; 0.15-1.40; p = 0.016 (sour); ß = 0.74; 0.22-1.25; p = 0.006 (bitter)] and waist circumference [ß = 0.05; 0.01-0.08; p = 0.012 (salty); ß = 0.03; 0.01-0.05; p = 0.020 (sweet); ß = 0.04; 0.01-0.08; p = 0.020 (sour); ß = 0.04; 0.01-0.07; p = 0.007 (bitter)] were associated with the recognition thresholds. Age was associated with salty (ß = 0.06; 0.01-0.12; p = 0.027) and BMI with sweet thresholds (ß = 0.06; 0.01-0.11; p = 0.019). CONCLUSIONS: Taste recognition thresholds were higher in uncomplicated T2DM, and central obesity was significantly associated with this impairment. Hypogeusia may be an early sign of diabetic neuropathy and be implicated in the poor compliance of these patients to dietary recommendations.

Preoperative oral immunonutrition versus standard preoperative oral diet in well nourished patients undergoing pancreaticoduodenectomy.

BACKGROUND: Pancreaticoduodenectomy is still associated to high morbility, especially due to pancreatic surgery related and infectious complications: many risk factors have already been advocated. Aim of this study is to evaluate the role of preoperative oral immunonutrition in well nourished patients scheduled for pancreaticoduodenectomy. METHODS: From February 2014 to June 2015, 54 well nourished patients undergoing pancreaticoduodenectomy were enrolled for 5 days preoperative oral immunonutrition. A series of consecutive patients submitted to the same intervention in the same department, with preoperative standard oral diet, was matched 1:1. For analysis demographic, pathological and surgical variables were considered. Mortality rate, overall postoperative morbility, pancreatic fistula, post pancreatectomy haemorrhage, delayed gastric emptying, infectious complications and length of hospital stay were described for each groups. Chi squared test, Fisher's Exact test and Student's T test were used for comparison. Differences were considered statistically significant at p < 0.05. Statistics was performed using a freeware Microsoft Excel (®) based program and SPSS v 10.00. RESULTS: No statistical differences in term of mortality (2.1% in each groups) and overall morbility rate (41.6% vs 47.9%) occurred between the groups as well as for pancreatic surgery related complications. Conversely, statistical differences were found for infectious complications (22.9% vs 43.7%, p = 0.034) and length of hospital stay (18.3 ± 6.8 days vs 21.7 ± 8.3, p = 0.035) in immunonutrition group. CONCLUSION: Preoperative oral immunonutrition is effective for well nourished patients scheduled for pancreaticoduodenectomy; it helps to reduce the risk of postoperative infectious complications and length of hospital stays.

Blood pressure and sodium intake from snacks in adolescents.

BACKGROUND/OBJECTIVES: The relationship between sodium intake and arterial blood pressure (BP) values in adolescence is still controversial. The intake of high-sodium processed foods as snacks has gone up worldwide. The purpose of the present cross-sectional study was to analyze the association between BP values and sodium intake from snacks. SUBJECTS/METHODS: The mean weekly consumption of snacks was evaluated in 1200 randomly selected adolescents aged 11-13 years by a food-frequency questionnaire; their anthropometric and BP values were measured by trained researchers. A dietary 24-h food-recall questionnaire was randomly given to 400 of the 1200 adolescents. RESULTS: Mean sodium intake from snacks was 1.4 g/day. Systolic and diastolic BP (SBP and DBP, respectively) significantly increased from the lower to the higher tertile of sodium from snacks and with increasing frequency of salty snacks consumption. In a multiple logistic regression model, both being in the highest SBP quartile and in the highest DBP quartile were significantly associated with the intake of sodium from snacks (odds ratio (OR)=1.48; 95% confidence interval (CI) 1.14-1.91 and OR=2.17; 95% CI 1.68-2.79, respectively), the consumption of >2/day salty snacks (OR=1.86; 95% CI 1.32-2.63 and OR=2.38; 95% CI 1.69-3.37, respectively) and body mass index (OR=1.26; 95% CI 1.22-1.31 and OR=1.14; 95% CI 1.10-1.18, respectively) but not with age, sex or exercise levels. In the 400 individuals, the average total sodium intake was 3.1 g/day and was significantly higher in individuals belonging to the highest quartile of SBP and DBP. CONCLUSIONS: Sodium intake from snacks was almost half of the average daily sodium consumption and was significantly associated with BP values in adolescents.

Insertion of a loxP site in a size-reduced human accessory chromosome.

The generation in vitro of mammalian artificial chromosomes, in view of the possibility of developing new technologies for gene therapy, is still an ambitious goal. Mammalian artificial chromosomes, to be used as cloning and expression vectors, have been constructed either by de novo synthesis or by reduction of pre-existing chromosomes. In the work here reported, we introduced a loxP sequence into the pericentromeric region of a chromosome 9-derived X-ray-reduced minichromosome, with the purpose of generating a human chromosome vector (HCV). The modified accessory chromosome is linear and mitotically stable, has lost at least 1400 kb of alpha satellite DNA and normally binds CENP-B, CENP-C and CENP-E. The efficiency of gene targeting via loxP mediated homologous recombination was tested using the histone H2B-Green Fluorescent Protein chimaeric gene as a reporter. The frequency of site-specific insertion of the exogenous sequence was found to be about 50% and to occur in a controlled way with regard to the number of copies. The expression level of the fusion protein was stable over prolonged time in culture.

Gene targeting to the centromeric DNA of a human minichromosome.

A human supernumerary minichromosome (MC), previously identified as a derivative of chromosome 9, has been introduced into Chinese hamster ovary (CHO) cells by means of cell fusion. A hybrid clone containing the MC as the only free human chromosome was isolated. A selectable marker gene (neo) inserted into a yeast artificial chromosome (YAC) has been successfully targeted to the MC centromeric DNA via co-transfection with chromosome-9-specific alpha satellite DNA. In situ hybridization and Southern blotting experiments demonstrated that the intact neo gene was integrated into the MC centromeric DNA. Studies on the clonal distribution and on the stability of the MC either in the presence or in the absence of the selective agent have been carried out. The MC is susceptible to further manipulations and may thus represent a model for the construction of a large-capacity vector for somatic gene therapy.

DNA fingerprint analysis for the detection of induced mutations in mammalian cells in culture.

A mutation assay in cultured mammalian cells based on the direct analysis of minisatellite DNA was developed. Band pattern variations reflect DNA alterations ranging from single base changes to complex rearrangements. By DNA fingerprinting a large number of autosomal loci throughout the human genome can be simultaneously checked, therefore minimizing the size of the samples of cell colonies to be scored in the absence of phenotypic selection. For the mutation assay chinese hamster cells (V79) were treated with Nitrosoguanidine and 14 independent colonies were isolated and expanded. DNA fingerprints were obtained after digestion of the DNA extracted from each clone with bothHinfI andHae III, and hybridisation with both 33.15 and 33.6 probes. Twelve colonies from untreated cells were also analysed. Several differences in the band pattern of treated colonies were observed when compared with untreated cells; digestion withHae III and hybridisation with 33.15 probe allowed the detection of the highest frequency of induced variants. The results suggest that minisatellite sequences are hypermutable sites that can be used to monitor the mutagenic potential of chemical agents directly at the DNA level, without phenotypic selection. Moreover, with the method herein decribed, it is possible to distinguish between true mutations and epimutations, such as those caused by changes in DNA methylation.

Assignment of the human cytokeratin 3 gene (KRT3) to 12q12-->q13 by FISH.

We used fluorescence in situ hybridization to localize the human gene for cytokeratin 3 (KRT3), a member of the type II subfamily of cytokeratins, within the human genome. The results show that KRT3 is located within chromosome region 12q12-->q13. All human type II keratin genes mapped to date have been assigned to chromosome 12, where they are likely to be organized into one homotypic cluster.

Variation of minisatellites in chemically induced mutagenesis and in gene amplification.

A mutation assay in cultured mammalian cells was developed based on direct analysis of minisatellite DNA. Chinese hamster cells (V79) were mutagenized with nitrosoguanidine and independent colonies were isolated and expanded. DNA fingerprints were then obtained after digestion with HinfI or HaeIII and hybridization with 33.15 and 33.6 probes (Jeffreys et al., 1985). 12 colonies from untreated cells were also analyzed. Digestion with HaeIII and hybridization with 33.15 probe detected the highest frequency of induced variants. The results suggest that minisatellite sequences are hypermutable sites that can be used to monitor the mutagenic effect of chemical agents. We have also analyzed the DNA fingerprints of 17 independent Chinese hamster (CHO) cell lines carrying amplification of the CAD gene. The DNA fingerprint analysis showed a variation in minisatellite regions in 3 lines while no variation was observed in independent colonies from the CHO parental cell line. The results suggest that these sequences may be hot spots for recombination during gene amplification.

Assignment of the human urokinase receptor gene (PLAUR) to 19q13.

Through in situ hybridization of a cDNA probe to metaphase chromosomes, we localized the gene for the human urokinase receptor (PLAUR) on chromosome 19. RBG-banding permitted subchromosomal localization of the PLAUR gene to 19q13.

Assignment of the human connexin 32 gene (GJB1) to band Xq13.

The chromosomal localization of the human gene coding for connexin 32 (GJB1) was determined by in situ suppression hybridization (ISSH). The results allowed assignment of the gene to band Xq13, thus refining previous localization data obtained by means of somatic cell hybrid analysis.

An improved method for chromosome banding after fluorescence in situ hybridization: use of a tetramethylrhodhamine-conjugated BrdU antibody.

A method for high quality chromosome banding after in situ hybridization with biotinylated probes has been developed. Fluoresceine-conjugated avidin is used for probe detection, while chromosome banding is performed with a tetramethylrodhamine-conjugated anti-BrdU antibody. In this way probe localization and chromosome identification can be performed simultaneously simply by changing the incidental light wavelength.

Molecular cloning of DNA from a sorted human minichromosome.

A human supernumerary minichromosome (MC), found in a newborn baby and sorted on a fluorescence-activated cell sorter (FACS-440) has been previously described [Ferretti et al., Cytotechnology 1 (1987) 7-12]. We report here on the construction of a library of EcoRI fragments in the phage lambda gtWES.lambda B', starting from 7.5 ng of MC DNA, and describe the isolation of single-copy DNA clones from the library in a two-step procedure. We employed in situ hybridization to unambiguously select the clones specific for the MC, and used three of these clones to demonstrate that it originated from chromosome 9.

Localization of DNA probes tightly linked to the Friedreich's ataxia locus by in situ hybridization in a case of pericentric inversion of chromosome 9.

The gene for Friedreich's ataxia (FA), an autosomal recessive neurodegenerative disorder, has been recently assigned to the long arm of chromosome 9. Linkage disequilibrium between FA and two diverse chromosome 9 markers, D9S5 and D9S15, has been detected in French, French-Canadian and Italian populations. Here, we report the physical localization of these loci by in situ hybridization of probes 26P and MCT112S identifying the D9S5 and D9S15 loci, respectively. Experiments performed on lymphocytes carrying a chromosome 9 pericentric inversion have allowed us to assign both the loci to band 9q21. Furthermore, in situ hybridization data and partial sequencing of the probe MCT112S indicate the presence of alphoid satellite DNA within this region. This suggests that MCT112S is more proximal to the centromere than 26P.

The origin of a morphologically unidentifiable human supernumerary minichromosome traced through sorting, molecular cloning, and in situ hybridisation.

A supernumerary minichromosome has been detected in a severely malformed patient. Attempts at identifying the marker by conventional approaches were unsuccessful. The physical isolation of the minichromosome by fluorescence activated sorting, molecular cloning of its DNA, and in situ hybridisation experiments performed with single copy DNA probes allowed us to show that it was derived from a rearrangement involving the centromere and the proximal region of the short arm of chromosome 9.

Aneuploidy induced by chloral hydrate detected in human lymphocytes with the Y97 probe.

Chloral hydrate (CH) has been assayed for its ability to induce chromosome number variation in human lymphocytes in culture. Aneuploidy induction has been detected by means of in situ hybridization on interphase nuclei with a chromosome Y-specific DNA probe. A dose-dependent increase in the number of hyperdiploid nuclei was found at CH concentrations ranging from 250 to 750 micrograms/ml. These results represent a further contribution to the validation of the method which gave a positive response with drugs characterized by different mechanisms of action and therefore may be of general use in detecting aneuploidy in mammalian cells.

Effects of arachidonic acid on hepatic lipids in ethanol-fed rats.

The effects of arachidonic acid supplementation on rats fed ethanol employing an ad libitum schedule have been reported to be different from those observed when rats are fed in more limiting, matched fashion. To reexamine this issue, rats were fed unrestricted amounts of a diet in which 36% of the energy was provided by either ethanol or isocaloric amounts of carbohydrate. In half the animals, 7% of fat consisted of arachidonic acid. Despite earlier reports to the contrary, arachidonic acid had no effect on weight gain and did not attenuate the ethanol-induced fatty liver. Arachidonate supplementation tended to increase hepatic total lipids and triacylglycerols, and to potentiate the ethanol-induced elevation of cholesterol esters. Our present results are consistent with those previously reported using pair-feeding techniques in which dietary intakes are somewhat limited. Thus, regardless of the feeding technique employed, relative arachidonic deficiency cannot be involved to explain the lipid accumulation observed after chronic ethanol consumption.

Aneuploidy assay on diethylstilbestrol by means of in situ hybridization of radioactive and biotinylated DNA probes on interphase nuclei.

Aneuploidy tests by means of in situ hybridization with chromosome-specific DNA probes on interphase nuclei have been carried out on human lymphocytes treated with diethylstilbestrol (DES). A DNA probe specific for chromosome Y (Y97), either radioactive or biotinylated, was used for the assays. Autoradiography or FITC-conjugated antibiotin antibodies were employed to visualize the hybridization sites. A significant increase of hyperdiploid nuclei was obtained with both procedures and a dose-related effect was revealed using the biotinylated probe. The results obtained, while giving further support to the evidence that DES is able to induce aneuploidy in cultured human cells, also indicate that the sensitivity of the assay can be improved by using biotinylated probes coupled with fluorescent antibodies.

Fragile-X mental retardation in a large five-generation family. A clinical and cytogenetic study.

A number of problems concerning both clinical and genetic or cytogenetic aspects of the fragile-X syndrome remain unsolved. In the present work, a large 5-generation fragile-X family has been clinically and cytogenetically investigated. The results of our study indicated that an unusually high proportion of affected males was present in the family examined; all fragile-X-positive males were profoundly retarded and showed the phenotype typically described for this syndrome; moreover, we observed a variability of penetrance within the pedigree and all fragile-X-positive females in the 4th and 5th generation had some degree of mental impairment. A multistep mutation model has been proposed in order to explain some of these findings.