Biomedical subjects
Publications and source records attributed to M Genovese.
We demonstrate a method to reconstruct the joint photon statistics of two or more modes of radiation by using on/off photodetection performed at different quantum efficiencies. The two-mode case is discussed in detail, and experimental results are presented for the bipartite states obtained after a beam splitter fed by a single photon state or a thermal state.
We present the first observation of two-photon polarization interference structure in the second-order Glauber correlation function of two-photon light generated via type-II spontaneous parametric down-conversion. In order to obtain this result, two-photon light is transmitted through an optical fiber and the coincidence distribution is analyzed by means of the start-stop method. Beyond the experimental demonstration of an interesting effect in quantum optics, these results also have considerable relevance for quantum communications.
The distribution of bacterial communities terminal restriction fragment length polymorphism (T-RFLP) fingerprint patterns was evaluated at three proximal hydrocarbon-contaminated sites located within the harbour of Messina. In order to analyse the short-term variability of the individual terminal restriction fragment (T-RF) patterns, water samples were collected at the three sites on three occasions within 3 months (T(0), T(90) and T(91)). Four sample sizes, from 50 to 1000 ml for each collected sample, were analysed separately (36 total analysed samples) to evaluate the relationship between the sample size and the bacterial diversity estimates. The dominant T-RF groups mostly belonged to signatures of putative hydrocarbon-degrading bacteria, as revealed by the virtual analysis of the obtained bands. In order to test whether significant differences were occurring between the analysed samples, the Kruskal-Wallis non-parametric test was applied to the T-RF data set. Neither significant influence of the sample size nor short spatial variability within the three sampled sites was detected for each sampling time. On the contrary, significant temporal changes in the diversity of the bacterial communities were observed. These results were confirmed by the non-metric multidimensional scales (nMDS) analysis of the whole set of samples, which indicated three main groups corresponding to the three different sampling times. In summary, the T-RFLP technique, although a polymerase chain reaction-based method, proved to be a suitable technique for monitoring polluted marine environments, typically characterized by low diversity and high relative abundances of a few dominant groups.
OBJECTIVE: To assess the efficacy of interferon beta (IFN beta) in combination with methotrexate in treatment of patients with rheumatoid arthritis. METHODS: 209 patients with active rheumatoid arthritis, who had been on methotrexate for at least six months and at a stable dose for four weeks before study entry, were randomised in double blind fashion to receive placebo (0.05 ml or 0.5 ml), IFN beta 2.2 microg (0.05 ml), or IFN beta 44 microg (0.5 ml), given subcutaneously three times weekly for 24 weeks. The primary efficacy measure was a change in radiological scores at week 24. The secondary endpoint was the proportion of patients who met the ACR 20% improvement criteria at the end of the study. Synovial biopsy specimens were obtained before and after treatment from a subset of patients. Immunohistochemistry was used to detect the presence of inflammatory cells and the results were measured by digital image analysis. Collagen crosslinks were measured in urine at different times throughout the study. RESULTS: Analysis of radiological scores and clinical variable showed no changes in any of the groups, and there were no differences between the groups. On microscopic analysis of synovial tissue there was no significant change in the scores for infiltration by inflammatory cells after IFN beta treatment. Urinary levels of collagen crosslinks were unchanged between the treatment groups. CONCLUSIONS: At the doses tested, treatment with IFN beta three times weekly in combination with methotrexate did not have a clinical or radiological effect in patients with rheumatoid arthritis.
OBJECTIVE: To report the safety and efficacy of leflunomide (LEF) in combination with infliximab (INF) for the treatment of rheumatoid arthritis. METHODS: In an open, multicenter, retrospective study, data were collected on the safety and efficacy of LEF and INF. RESULTS: Eighty-eight patients received the combination of LEF and INF for an average of 6.6 months and a total exposure of 581 patient-months. The mean duration of LEF was 17 +/- 9 months (range 3-32 months; median 18.5 months) with an average of 4.8 INF infusions per patient. In all but 3 subjects, LEF was used initially and INF was added later. Infusion reactions occurred in 3 patients (0.7% of all infusions). A total of 34% of subjects experienced adverse events and in 6 (6.8% of the group) these were deemed serious. Ten infections occurred when patients were taking the combination; 9 patients recovered fully and 1 died of bacterial pneumonia. A lifetime smoker developed lung cancer and another patient was found to have colon cancer. CONCLUSIONS: The adverse events noted within the combination therapy group were in keeping with the known risks of each drug when used individually. Limited data were available on efficacy, but a general improvement in disease control was noted with the combination of drugs, which for most patients involved the addition of INF to previous use of LEF.
All Prader-Willi syndrome (PWS) and 75% of Angelman syndrome (AS) patients have specific DNA methylation pattern alterations that can be used for diagnostic evaluation. The methylation testing identifies a significantly higher proportion of patients as compared to fluorescence in situ hybridization (FISH)-based microdeletion analysis and is thus a useful diagnostic evaluation for clinically suspect, but FISH-negative, patients. We used two independent PCR-based protocols for methylation testing on fixed cell specimens archived after FISH analyses. Changes in DNA methylation due to the procedure of cell fixation were ruled out by testing control specimens before and after fixation. Then methylation testing was carried out on 20 standard fixed-cell supsensions from people suspected for PWS or AS. These fixed specimens were stored after negative FISH analysis for up to 4 years at 4 degrees C in 3:1 methanol/acetic acid. Methylation patterns associated with AS (one specimen) and with PWS (one specimen) were identified for both protocols. The observed methylation patterns were concordant with the phenotypes of the positive individuals and for the two protocols used. We have, thus, shown that archived fixed-cell suspensions from individuals suspected as PWS or AS that were negative for cytogenetic/FISH microdeletions, can now be re-evaluated with PCR-based methylation testing without the need for additional blood samples from the previously studied individuals.
We have developed a novel PCR-based method for studying DNA methylation in the proximal region of 15q, using restriction analysis after bisulfite treatment of genomic DNA. This protocol can be used for the diagnosis of Prader-Willi and Angelman syndromes. Unlike the recently reported methylation-specific PCR protocol, our method avoids the use of multiplex amplification, thus overcoming the need to adjust relative primer amounts and the risk of obtaining false-negative results.
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Using a nonair-drying modification of a method for longitudinal sectioning of metaphase spreads on glass slides [Wen et al., 1997], we have studied 14 preidentified X chromosomes (10 from fragile X specimens and 4 controls) with transmission electron microscopy (TEM). Four of 10 X chromosomes from fragile X specimens exhibited lighter chromatin density in the area of and distal to the fragile site, most pronounced under dark-field TEM. A clear line of separation at the fragile site locus was also observed by TEM in an X chromosome with no visible fragile site after Q-banding. We hypothesize that these areas of lighter density, including lines of separation, precede the appearance of the fragile site that is commonly observed using light microscopy.
When the blood cells of ascidians Phallusia mammillata are stained with the ligand 2,2'-bipyridine, those cells which contain vanadium(III), in an easily sequestered form, take up the stain producing in situ, a purple complex. This material extracted displays spectral characteristics consistent with the formation of an oxo-bridge vanadium(III) bipyridine dimer. The staining is localized in the signet ring cell, a bivacuolated cell, a cell type with numerous darkly staining compartments, and also by the vacuolated amoebocyte. The possible ramifications of these observation are discussed in relation to the delineation of the signet ring cell lineage.
Duplication 8p usually results in a syndrome characterized by profound mental retardation, mild facial anomalies, and malformations of hand, heart, and brain. We report on a large kindred segregating a Y;8 translocation in whom several individuals have duplication 8p22-->8pter. These individuals have normal adaptive function despite their unbalanced karyotype. The family was studied with G-banding and fluorescent in situ hybridization (FISH) using probes to chromosomes 8 and Y. Comparison of this family with other reported cases defines a mild clinical outcome for trisomy 8p22-->8pter in contrast to the severe findings when the duplication involves a longer, more proximal segment.
During a study of the familial aggregation of Down syndrome (DS) and Alzheimer disease (AD), we observed an increase in mosaicism for disomy 21 in older individuals with DS. In a total of 213 DS subjects who were studied cytogenetically, only 1 of 121 (0.8%) under age 45 exhibited mosaicism, while 14 of 92 (15.2%) who were age 45 or older had mosaicism. Mosaicism in this report connotes "low-level" mosaicism, where all 15 individuals exhibited a modal chromosome number of 47 (i.e., trisomy 21), and at least two cells lacked one of the three chromosomes 21. The occurrence of aneuploidy for chromosomes 15, 17, and X increased with age, and an inverse correlation between chromosome loss and size was also observed. Because older individuals had not been karyotyped at birth, it was not possible to determine whether our observations were due to either increased survival of mosaic individuals or accumulation of disomy 21 cells via increased chromosome loss with aging of the trisomy 21 individual. Using a modeling approach involving life table methods, we obtained results that suggested acquired mosaicism as the predominant mechanism to explain our findings. These results support the hypothesis that as individuals with DS age, there is an increased loss of chromosome 21.
In Italy, systematic mandatory tetanus immunization of children started in 1968. In 1989, immunity against tetanus was assessed in a random sample of 758 healthy subjects aged 3-20 y, from four Italian cities. There were 257 subjects 3-5 y old all residing in Southern Italy and 501 subjects 11-20 y old from both the South and North. The overall prevalence of non-immune subjects was 19.1%, without difference by sex. The rates of subjects lacking protective antibody titres was 25.3% in children 3-5 y old (all coming from South and the islands), 11.5% in those 11 y old, and 18.9% in the 18-20 y age-group, respectively. Subjects 11-20 y old residing in the South and the islands were more likely to be non-immune that those residing in the North (20.2% vs 6.0%; P < 0.01). Socio-demographic indicators such as lowest paternal education and largest family size were both unassociated with lack of protective antibodies. These findings indicate that an high rate of children in South of Italy do not have protective antibody levels, probably as consequence of lack of compliance with the vaccination programme. More efforts should be addressed to decrease geographical inequalities in the delivery of health care.
Lemierre's syndrome is an acute medical condition characterized by anaerobic oropharyngeal infection leading to septic thrombophlebitis of the internal jugular vein. The illness is often complicated by septic pulmonary emboli and distant metastatic infections. Treatment consists of surgical drainage of purulent collections and long-term intravenous antibiotic therapy. Although Lemierre's syndrome is rare, it is potentially fatal and remains an important entity for clinicians to recognize and treat appropriately.
The results of serological assays performed during the Italian controlled efficacy trial of two acellular vaccines and one whole-cell vaccine against pertussis are described and discussed. We examined 312 episodes of suspected pertussis disease confirmed by B. pertussis isolation, and 2862 episodes without any evidence of B. pertussis or B. parapertussis infection. Higher mean log ELISA titres for IgG to pertussis toxin (PT) were found in the acute-phase serum specimens of those children vaccinated with the acellular pertussis vaccines and particularly in the SmithKline Beecham DTaP vaccine group. These apparently anamnestic responses were responsible for the observed differences in ELISA diagnostic sensitivity exhibited by IgG to PT and by IgG to filamentous haemagglutinin (FHA). We observed minimal IgA responses to PT but vigorous IgA responses to FHA in the convalescent-phase serum specimens for the acellular pertussis vaccine groups, which contributed to the sensitivity of the serological series of assays for diagnostic purposes.
Low fragile X frequencies have been commonly observed in chorionic villus sample (CVS) cultures, compared to subsequent analysis in whole blood or products of conception (POC). To investigate possible mechanisms for this effect, CVS cultures from a previously identified fragile X positive male, were restudied and compared to subsequent POC cultures from lung, muscle, skin, and thymus. Cultures were exposed, for the last 24 hours before harvesting, to FUdR, excess thymidine, and a combination of both. For CVS, only those cultures that were exposed to a combination of FUdR and excess thymidine showed positive cytogenetic findings (1/90 or 1.1%), agreeing with our original positive cytogenetic results (2/86 or 2.3%) for cultures exposed to excess thymidine. Fragile X frequencies in the POC tissues from this fetus increased to an average of 14%. PCR analyses showed full mutations (> 200 CGG repeats) in uninduced CVS cultures but induced cultures exhibited apparently smaller sizes in the range of 120-180 repeats. The results showed variability. In one instance, the banding pattern from one of the uninduced cultures was similar to the results where cultures were exposed to a double induction system. When PCR analyses were conducted on induced POC cultures, full mutations were observed in virtually all samples. Southern blot genomic analysis using probe StB12.3 showed an unmethylated full mutation in CVS cultures. Southern blot patterns from cultures of muscle revealed size variations of DNA bands in the premutation range representing unmethylated DNA as well as methylated full mutations. Finally, variations were also observed in lung and skin cultures, compared to CVS and muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
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