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Biomedical subjects

M Gatti

Publications and source records attributed to M Gatti.

At least 91 records · Page 5Linked to original sources
PubMed1991

Observations made on strains of Campylobacter spp. isolated in 1989 in northern Italy.

Over a 12-month period (1989), 192 thermophilic campylobacters (190 from stool and two from blood specimens) were isolated. All the strains were identified as far as species and biotype was concerned and 89 were also serotyped according to the Lior method. C. jejuni (90.10%) was the species most frequently isolated (mainly biotype I) while the most frequent serogroup was LIO 4. Erythromycin-resistance was found in only 15 strains, but while it was very low for the species C. jejuni (1.16%), it was frequent for C. Coli (68.42%), mainly for biotype I (73.33%). Moreover, eight strains of thermophilic campylobacters resistant to nalidixic acid (three strains of C. jejuni and five strains of C. coli) were found.

Bacterial Typing Techniques↗
PubMed1990

Transcription of a satellite DNA on two Y chromosome loops of Drosophila melanogaster.

Primary spermatocyte nuclei of Drosophila melanogaster exhibit three giant lampbrush-like loops formed by the kl-5, kl-3 and ks-1 Y chromosome fertility factors. Detailed mapping of satellite DNA sequences along the Y chromosome has recently shown that AA-GAC satellite repeats are a significant component of the kl-5 and ks-1 loop-forming regions. To determine whether these simple repeated sequences are transcribed on the loop structures we performed a series of DNA-RNA in situ hybridization experiments to fixed loop preparations using as a probe cloned AAGAC repeats. These experiments showed that the probe hybridizes with homologous transcripts specifically associated with the kl-5 and ks-1 loops. These transcripts are detected at all stages of development of these two loops, do not appear to migrate to the cytoplasm and are degraded when loops disintegrate during the first meiotic prophase. Moreover, an examination of the testes revealed that the transcription of the AAGAC sequences is restricted to the loops of primary spermatocytes; the other cell types of D. melanogaster spermatogenesis do not exhibit nuclear or cytoplasmic labeling. These experiments were confirmed by RNA blotting analysis which showed that transcription of the AAGAC sequences occurs in wild-type testes but not in X/O testes. The patterns of hybridization to the RNA blots indicated that the transcripts are highly heterogeneous in size, from large (migration at limiting mobility) to less than 1 kb. We discuss the possible function of the AAGAC satellite transcripts, in the light of the available information on the Y chromosome loops of D. melanogaster.

Animals↗
PubMed1990

Central vision impairment from optic disk drusen in the young.

Reduced visual acuity apparently due to the effects of drusen on the optic nerve is rare. We describe two young patients with central vision impairment from optic disk drusen: a man with a reduction of visual acuity to light perception, a women with a very fast evolution of the drusen, that, not visible at the clinical onset, could be documented in autofluorescence one month later. The appearance of drusen in disks initially diagnosed as pseudopapilledema is supposed to be related to axonal degeneration from abnormal axoplasmic flow.

Adult↗
PubMed1990

[Tungiasis. A clinical case].

Tungiasis is a cutaneous infestation by the female sand flea, Tunga penetrans. Because of the increase in international travel, the disease is reported in Europe, in spite of it being formerly restricted to the equatorial zones. This report describes a case of tungiasis and discusses clinical features, diagnosis and treatment.

Adult↗
PubMed1990

[Dermatomycoses observed at the Dermatologic Clinic, Pavia University. 2) Pathology of Microsporum gypseum].

Microsporum gypseum infections are 0.4% of 4900 suspected dermatomycoses examined with direct microscopic exam and culture on Lactrimel medium or D.T.M. This geophilic dermatophyte was isolated in 20 cases (1.5% of all dermatophytes). More frequently M. gypseum caused tinea corporis (13 cases: 65%) and rarely tinea capitis (2 cases: 10%), tinea faciei (2 cases), tinea manus (2 cases) and tinea cruris (1 case). Both sexes are equally affected. Direct microscopic exam was negative in 2 cases. This dermatophyte was more frequently isolated during the summer and fall. Finally M. gypseum was not isolated in tinea pedis and tinea unguium.

Academic Medical Centers↗
PubMed1989

Pityriasis versicolor in the aged: a clinical investigation and epidemiological survey in 190 elderly hospitalized patients.

190 subjects over 60 yrs of age, hospitalized for long stays were checked for scaling and hyperpigmented patches of P. versicolor. 20 patients (10.5%) showed no clinical lesions; 170 patients (89.5%) showed scaling and/or hyperpigmented patches of which 13 patients (6.8%) on direct microscopic exam showed hyphae and yeasts of M. furfur, 64 (33.6%) only globular forms of P. orbiculare and 113 cases (59.4%) showed no fungal elements. Wood's light examination showed that 38 subjects (20%) were 6 positive for M. furfur and 23 for P. orbiculare while in the other 9 no fungal elements were observed on microscopic exam. Whereas 48/132 patients negative to Wood's light were positive for yeasts on microscopic exam (false negative). This study indicates that P. versicolor is not rare in the elderly and that Wood's light examination is not diagnostic. There was no relationship between P. versicolor and underlying illness.

Age Factors↗
PubMed1989

Superficial mycoses observed at the Department of Dermatology of the University of Pavia. A 13-year survey.

Over a period of 13 years, 4,100 specimens were cultured for fungi. Pityriasis versicolor (Malassezia furfur) was demonstrated in 17.6%, dermatophytosis in 34.6% and candidiasis in 10.8%. The most frequently isolated strains were M. canis (31.5%), T. rubrum (26.3%), E. floccosum (19.7%), T. mentagrophytes (19.3%) for the dermatophytes and C. albicans (88.9%). Those rarely seen were: M. gypseum, T. violaceum, M. audouini, T. schoenleinii. We observed the absolutely complementary results of the microscopic examinations and the cultures of the specimens.

Candidiasis, Cutaneous↗
PubMed1989

Genes controlling essential cell-cycle functions in Drosophila melanogaster.

On the basis of the hypothesis that mutants in genes controlling essential cell cycle functions in Drosophila should survive up to the larval-pupal transition, 59 such 'late lethals' were screened for those mutants affecting cell division. Examination of mitosis in brain neuroblasts revealed that 30 of these lethals cause disruptions in mitotic chromosome behavior. These mutants identify genes whose wild-type functions are important for: (1) progression through different steps of interphase, (2) the maintenance of mitotic chromosome integrity, (3) chromosome condensation, (4) spindle formation and/or function, and (5) completion of cytokinesis or completion of chromosome segregation. The presence of mitotic defects in late lethal mutants is correlated tightly with the presence of defective imaginal discs. Thus, the phenotypes of late lethality and poorly developed imaginal discs are together almost diagnostic of mutations in essential cell-cycle functions. The terminal phenotypes exhibited by these Drosophila mitotic mutants are remarkably similar to those observed in mammalian cell-cycle mutants, suggesting that these diverse organisms use a common genetic logic to regulate and integrate the events of the cell cycle.

Animals↗
PubMed1989

Effects of medium-term PUVA therapy on peripheral T-lymphocyte subsets in psoriatic patients.

Three to four months' PUVA treatment is a widely-adopted procedure to induce psoriasis remission and for the purpose of this study is called "medium-term". The 32 psoriatic patients considered revealed a statistically significant baseline decrease in OKT3+ (p less than 0.001), OKT4+ (p less than 0.001) and OKT8+ (p less than 0.001) as compared with 40 healthy controls, while OKT4/OKT8 was normal. Variance analysis within the psoriatic group failed to reveal further significant variation in the immunological parameters during the 3 months under study. Nevertheless, there was a marked trend towards a reduction in OKT4+ cells and OKT4/OKT8 as compared with baseline values after 3 months. These results suggest that "medium-term" PUVA therapy does not statistically restore the pre-existing baseline changes in T-lymphocyte subsets of the psoriatic patients. The non-statistically significant effects as regards OKT4+ may be due to the small number of patients who reached 3 months' treatment (9 patients) but could be regarded as the first step towards the significant changes described here in long-term PUVA-treated psoriatic patients.

Adult↗
PubMed1989

Changes in the water holding capacity of psoriatic stratum corneum in vivo.

This study investigated the functional capacity of the stratum corneum of psoriatic skin to bind water in vivo during a relatively long period of time (water holding capacity--WHC). An electrical capacitance test was applied to the psoriatic skin on the elbows, perilesional skin and apparently normal skin of 11 patients and the elbows of 10 controls. Measurements of electrical capacitance were performed using a Corneometer Schwarzhaupt for 25 min. The WHC levels were calculated for this period. Our results demonstrate that the WHC of psoriatic stratum corneum does not differ from controls in the first 10 min. Only after the 20th min do the WHCs differ significantly (p less than 0.02). Despite the biochemical keratin changes in psoriatic plaque, the latter is highly hygroscopic, in particular in the first minute after bathing. Perilesional skin binds water like the stratum corneum of controls, though not beyond the 20th minute after bathing.

Adult↗
PubMed1989

Omental autoimplantation of splenic tissue and intravenous pneumococcal challenge. A comparative study in rats.

Splenectomized subjects show a higher incidence of myocardial ischemia and of Overwhelming Post-Splenectomy Infection (OPSI). It is doubtful that implanted splenic tissue guarantees an adequate protection from OPSI. The histological characteristics and the capacity of protection from OPSI of two models of omental autoimplantation of splenic tissue in rats were examined. The implanted splenic tissue offers a significant protection from pneumococcal sepsis, even though there is no relation between implant architecture and survival rate.

Animals↗
PubMed1989

[Findings on dermatomycoses observed at the Dermatologic Clinic, University of Pavia. A third pathology caused by Trichophyton rubrum].

From 1974 to 1988 T. rubrum have been isolated in 304 cases (27.8% of dermatophytes) in the Department of Dermatology in Pavia and it is the second most frequent fungus after M. canis. Males are more frequently affected (61.1%) than females (38.9%). A single localization was found in 82.2% of the cases and two or more types of "Tineae" only in 17.8%. The age-group 31-40 is more frequently affected (29%). The most frequent dermatophytosis caused by T. rubrum was Tinea pedis (33.9%) while Tinea capitis resulted a very rare localization (2.1%). An increase of T. rubrum infections is noted particularly in the last years.

Adolescent↗
PubMed1989

[Efficacy of fenticonazole in patients with pityriasis versicolor].

Thirty patients suffering from Pityriasis versicolor were treated with fenticonazole in cream or lotion form with two applications a day. At microscopy, Malassezia furfur was encountered in 25 cases and Pityrosporum orbiculare in 5. Disappearance of the yeast was obtained on average in 2 weeks of treatment. Measurement of sebum content with a Sebumeter apparatus did not reveal significant difference (p greater than 0.05) between patients suffering from Pityriasis versicolor and controls and in treated patients, in the course of topical therapy.

Administration, Cutaneous↗
PubMed1989

A one-year study on thermophilic campylobacters isolated from fecal specimens.

During a 12-month period, a systematic screening for thermophilic campylobacters was done on 5723 stool samples of hospitalized patients and out-patients who required stool culture tests for gastrointestinal disturbances. Campylobacter strains were isolated in 130 samples (2.27%) and Campylobacter jejuni (mainly biotype II) was the species most frequently isolated. No pronounced seasonal pattern was evident and the age at which infection was more often observed was that from 6 to 24 months. Erythromycin-resistance was found in only 8 strains and it was significantly more frequent among Campylobacter coli strains.

Adolescent↗
PubMed1988

Experimental right ventricular outflow tract reconstruction with a composite Mitrathane monocusp patch: preliminary results.

Twenty large white pigs underwent normothermic right ventricular bypass, pulmonary artery valve excision and right ventricular outflow tract (RVOT) reconstruction using a synthetic material (Mitrathane). The animals were divided in two groups (ten for each group) for the RVOT reconstruction model: Group I with a composite monocusp patch (with a new design geometrically related to pulmonary artery circumference) and Group II without a valve mechanism. Four early postoperative deaths occurred in Group I (unrelated to monocusp patch function) and seven in Group II (due to acute right ventricular failure). Follow up of the six animals of Group I was 600-630 (average 617.5) days and of the three Group II animals was 95-110 (average 101.6) days. In Group I haemodynamic studies showed no significant difference from preoperative values at 5 months while at 20 months there was a moderate valve insufficiency in all animals. In Group II severe right ventricular insufficiency was present in all animals and spontaneous death occurred after about 3 months. In Group I angiographic studies disclosed no evidence of graft calcification or stenosis while in Group II there was a moderate pulmonary trunk dilatation. Post mortem examination showed no signs of degeneration in any graft. Microscopic studies of both groups revealed an acellular layer of fibrin on the external surface and fibrous deposit on the inner part of the suture with the right ventricle. In Group I there were leukocyte and histocyte infiltration of the grafts. In these experiments our synthetic monocusp model showed good function and durability in comparison to a RVOT reconstruction without a valve mechanism.

Animals↗
PubMed1988

Y chromosome loops in Drosophila melanogaster.

Primary spermatocyte nuclei of fixed testes of Drosophila melanogaster exhibit three large clusters of thread-like structures, each consisting of two long, continuous, loop-shaped filaments. No comparable intranuclear structures are observed in spermatogonia, secondary spermatocytes or spermatids. The threads begin to form in young spermatocytes, grow throughout spermatocyte development, reach their maximum size in mature spermatocytes and disintegrate prior to meiotic metaphase I. The presence of each cluster of threads depends upon the presence of a specific region of the Y chromosome; when this region is deleted the cluster is absent, and when it is duplicated the cluster is also duplicated. Together these observations strongly suggest that these structures represent giant Y chromosome lampbrush-like loops analogous to those described in Drosophila hydei. Two antibodies, one polyclonal and one monoclonal, differentially react with the three loops of D. melanogaster. Moreover, two of these loops are specifically stained by Giemsa at pH 10. By indirect immunofluorescence with these antibodies followed by Giemsa staining, each loop can be unambiguously identified and its presence and normality readily assessed. This enabled us to perform fine mapping experiments to determine the relationships between the Y chromosome fertility factors and the loops. The loop-forming sites map within the kl-5, kl-3 and ks-1 fertility factors. Regions h3 and h21 of the Y chromosome correspond to the loop-forming sites of kl-5 and ks-1, respectively. Each of these regions contains about 1300 kb of DNA and spans about one-third of its locus. The loop-forming site of the kl-3 locus is coextensive with region h7-h9 which contains about 4300 kb of DNA and corresponds to the minimum physical size of this locus. These data suggest that each loop is an integral part of a different fertility factor, representing the cytological manifestation of its activity in primary spermatocytes. The kl-2, kl-1 and ks-2 fertility regions do not produce any visible intranuclear structure and do not affect the kl-5, kl-3 and ks-1 loops. Thus, these loci may either not form loops at all or produce loop-like structures that we are unable to see because they are physically minute, destroyed by our fixation procedure, or both.

Animals↗