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Biomedical subjects

P Mazza

Publications and source records attributed to P Mazza.

At least 73 records · Page 4Linked to original sources

Studies on the antibiotic resistance of Bacillus subtilis strains used in oral bacteriotherapy.

Bacillus subtilis antibiotic resistant strains used in oral bacteriotherapy were tested for the resistance to new therapeutically useful antibiotics. Chromosomal mutations originally selected in these strains proved to confer resistances also to these antibiotics. To investigate the stability of the antibiotic resistance markers present in B. subtilis O/C, T, N/R, SIN strains, we considered resistances to Chloramphenicol, Tetracycline, Rifampicin and Streptomycin. Resistances to Tetracycline, Rifampicin and Streptomycin were stably maintained for at least 200 generations in the absence of selective pressure. Chloramphenicol resistance proved to be inducible, showing a progressive loss when the resistant strain was grown in the absence of the antibiotic and a return to its original resistance levels after growth in the presence of the antibiotic. By in vitro and in vivo experiments we demonstrated the absence of homologous transfer of resistance markers among the resistant strains.

Anti-Bacterial Agents↗

Catecholamine-stimulated potassium transport in erythrocytes from normal and obese subjects.

The beta adrenergic-modulated Na+/K+ ATPase pump rate of red blood cells was measured in vitro in 18 non diabetic obese patients. After challenge of erythrocytes with beta adrenergic selective agonist Salbutamol, the decrement of the K+ concentration in the suspending medium was assumed to be related to the Na+/K+ ATPase pump rate or to the number of beta 2 receptors. The mean K+ uptake was markedly increased in the erythrocytes of obese patients (1.58 mEq/l SD 0.18) if compared with 38 normal subjects (1.30 mEq/l SD 0.11) and with a population of 30 atopic patients that we have previously reported to have a reduced red cells beta 2 receptor activity (1.09 mEq/L SD 0.11). These results are not consistent with the hypothesis that a reduction in the Na+/K+ ATPase pump rate (at least in red blood cells) may be responsible for decreased metabolic rates leading to obesity. Since the autonomic nervous system is involved in the regulation of the cardiovascular system, it is conceivable that an increased Na+ ATPase pump rate (or supersensitivity) may be responsible of the increased incidence of hypertension, congestive heart failure and unexplained sudden death associated with obesity in some patients.

Adult↗

Cutaneous response to intradermal histamine in lung cancer.

Recent evidence has suggested that human neoplastic patients show decreased blood histamine levels and cutaneous responses to intradermal histamine. In this study we evaluate the skin response to intradermal injections of histamine and IgE levels in 34 male patients with lung cancer (of which 21 had metastasis) and in 16 control subjects. Analysis of our data does not reveal any difference in the areas of wheal and flare between control subjects and lung cancer patients with or without metastasis. Moreover the evaluation of the different histologic cell type of lung cancer provides the same results. In addition, the sensitivity (Histamine Threshold Concentration) and reactivity (slopes) to histamine is not statistically different. No difference is found for IgE levels between controls and cancer patients. In the light of our finding we believe that in lung cancer patients skin response to intradermal histamine is not decreased, and therefore that the hypothesis concerning the existence of H1-histamine receptor antagonist released by tumour is not confirmed.

Aged↗

Studies on the genotoxic properties of essential oils with Bacillus subtilis rec-assay and Salmonella/microsome reversion assay.

Genotoxic properties of essential oils from Anthemis nobilis L., Artemisia dracunculus L., Salvia officinalis L., Salvia sclarea L., Satureja hortensis L., Satureja montana L., Thymus capitatus L., Thymus citriodorus Schreb., Thymus vulgaris L., Citrus bergamia Risso, were studied with Bacillus subtilis rec-assay and Salmonella/microsome reversion assay. The essential oil of Artemisia dracunculus L. "Piemontese" turned out to be active in the rec-assay but not in the Salmonella test. DNA-damaging activity was demonstrated to be due to the estragol component of the oil. Advantages of the combined use of these two short-term microbial assays in genotoxic studies are discussed.

Animals↗

Is interferon alpha in cutaneous T-cell lymphoma a treatment of choice?

This study was designed to evaluate the therapeutic efficacy and toxicity of recombinant interferon alpha-2a (rIFN alfa-2a) given as initial systemic therapy in untreated mycosis fungoides and/or Sezary's syndrome patients, at a slowly escalating schedule up to the maximal tolerated dose. At the same time this schedule was administered in patients who had relapsed or were refractory to previous treatment; 28 newly diagnosed and 15 previously treated patients entered the study. IFN was given daily with dose escalation from 3 to 18 MU. The last follow-up in June 1990 indicates that 90% of previously untreated patients who obtained a complete remission remain in continuous complete remission after 18 to 40 months and that 75% of previously untreated patients who obtained partial remission remain in partial remission after 20-44 months. The event-free survival projected, calculated using the Kaplan and Meier product limit technique, was 21% of all patients at 54.7 months (40% in the previously untreated groups and 14% in the previously treated group: P = 0.12). In conclusion, interferon is very effective as a single agent in cutaneous T-cell lymphomas.

Adult↗

Relationship between body mass and tolerance to physical stress in obese patients.

Eleven obese patients, 5 males; age: 17-42; body mass index (BMI): 40; % of ideal weight: 187%, and 10 normal subjects (5 males; age: 19-39; BMI: 22; % of ideal weight: 103%), both groups without heart and respiratory disorders, underwent a cycloergometric test with subsequent 20-watt increases every 4 min until exhaustion. During the test, ventilation/minute, expiratory gas concentration and heart rate were measured, and the anaerobic threshold (AT) was determined in each subject. The obese patients showed a significantly lower AT than normal subjects (p less than 0.01); showing values which decreased with the increase in the grade of obesity expressed in BMI or in percent of their ideal weight. Moreover, in the obese patients, the O2 consumption (VO2) had significantly increased compared to that of normal subjects at no resistance and at all work levels. The negative correlation between the AT value and the BMI in obese patients can attribute their increase in VO2 during stress to (1) the inertial overloading caused by obesity especially considering the adipose tissue of their legs, or (2) to their level of 'fitness' being lower than that of normal subjects.

Adolescent↗

Second primary cancer following Hodgkin's disease: updated results of an Italian multicentric study.

The risk of second primary cancer (SPC) was evaluated in 947 patients treated for Hodgkin's disease (HD) during the period January 1969 to December 1979. The median follow-up of this series was 10.5 years (range, 9 to 19). Treatment categories included radiotherapy (RT) alone (115 patients, 12%), chemotherapy (CHT) alone (161 patients, 17%), combined RT plus CHT (381 patients, 40%), and salvage treatment for resistant or relapsing HD (290 patients, 30.6%). Fifty-six SPCs were observed, occurring between 1 and 17 years from initial treatment. Among these, secondary acute nonlymphoid leukemia (s-ANLL) was the most frequent SPC (23 cases). Secondary non-Hodgkin's lymphoma (s-NHL) occurred in 5 patients, whereas a secondary solid tumor (s-ST) was observed in 28 patients. The calculated actuarial risk (+/- SE) of developing SPC was 5.0% (+/- 0.9%) and 23.1% (+/- 5.8%) at 10 and 19 years, respectively. Concerning treatment modalities and s-ANLL risk, no cases were observed in the radiotherapy group, whereas CHT plus RT and salvage groups showed the highest actuarial risk. This was, in fact, at 10 and 19 years, 3.1% (+/- 0.9%) and 8.1% (+/- 4.0%) in the former group, and 1.8% (+/- 1.0%) and 16% (+/- 9.0%) in the latter. A statistically significant difference was observed when the CHT plus RT group was compared with CHT and RT groups (P = .04). Concerning the relationships with chemotherapeutic regimens, 12 s-ANLL cases occurred in the mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) plus RT group, and only one case in the group receiving doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) plus RT. A statistically significant difference of s-ANLL actuarial risk was found comparing patients receiving MOPP plus RT to all other treatment groups (P = .04). With respect to s-ST, the actuarial risk at 10 and 19 years was 2.0% (+/- 0.6%) and 13.0% (+/- 3.8%), respectively. No significant differences were found among groups treated with different modalities. These data were confirmed by a multivariate analysis, which indicated treatment modality and age as independent variables for s-ANLL and s-ST development, respectively. Based on the prolonged follow-up analysis, the actuarial SPC risk at 10 years hereby reported should reflect the real SPC incidence in our series.

Actuarial Analysis↗

MACOP-B vs F-MACHOP in the treatment of high-grade non-Hodgkin's lymphomas.

From September 1988 two hundred-sixty-seven (267) untreated patients (pts) with stage II to IV high grade non Hodgkin's lymphoma (NHL) have been enrolled in a multicenter, randomized, still ongoing study, comparing two third-generation combination chemotherapy regimens, MACOP-B versus F-MACHOP. At the present time, 177 pts have completed the treatment program and are evaluable, with a median follow-up of 13 months. Clinical, histologic and laboratory characteristics are equally distributed in both groups. Among the 92 pts treated with MACOP-B, 58 (63%) achieved a complete remission (CR), 17 complete responders have relapsed (29%), and 21 have died (23%), including 3 treatment-related deaths. Among the 85 pts who received F-MACHOP, 65 (76%) achieved a CR, 9 complete responders have relapsed (14%), and 11 pts have died (13%), including 3 treatment related deaths. 30 months-projected survival is 64% for MACOP-B treated pts compared to 84% for F-MACHOP treated pts; 30 months-projected relapse- free survival is 80% and 84%, respectively. F-MACHOP seems to be superior in immunoblastic lymphoma (overall survival, OS, 82% vs. 54%) and in Burkitt-type lymphoblastic lymphoma (OS 100% vs, 42%). The degree of hematological and non-hematological toxicity was similar in both regimens. More reliable conclusions will be drawn after a longer follow-up.

Adult↗

Nine years' experience with ABMT in 128 patients with Hodgkin's disease: an Italian study group report.

One-hundred, twenty-eight patients with Hodgkin's disease in remission or who had failed a mechlorethamine, vincristine, procarbazine and prednisone (MOPP), a doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) and/or lomustine, etoposide and prednimustine (CEP) regimens have been treated with a high-dose therapy (HDT) containing cyclophosphamide, etoposide, carmustine (CVB) and autologous bone marrow transplantation (ABMT). Forty patients were treated while they were in resistant or progressive disease states using alternating MOPP/ABVD protocol; 15 patients received ABMT in first relapse; 51 patients had a complete remission (CR) with first-line therapy but later relapsed and then received conventional salvage therapy; 16 achieved no response or progression ("resistant relapse" patients) and 35 responded partially or completely ("sensitive-relapse" patients). The other 22 patients received ABMT in remission. Following HDT, 56 patients (52.8%) achieved CR and 23 patients (21.6%) achieved a partial remission for an overall response rate of 74.4%. Sixteen patients failed to respond and died in progressive disease 1 to 10 months (median 6 months) after ABMT. High-dose therapy produced severe toxicity including vomiting (100%), mucositis (75%) and liver enzymes and alkaline phosphatase elevations (51%). There were 10 treatment-related deaths. A multivariate analysis identified poor performance status and resistant-relapse patients as very important adverse risk factors for survival immediately after ABMT. These results, while validating this procedure for inducing remissions in advanced highly-treated patients, at the same time confirm the need of employing this approach in first relapse or in second complete remission after standard therapy and before ABMT or, in first complete remission in very high risk Hodgkin's disease patients. Our experience in 15 very poor prognosis Hodgkin's disease patients transplanted in first CR demonstrated to be much significant.

Adult↗

Biological studies on 1,2-benzisothiazole derivatives. IV. Relationships between chemical structure and genotoxicity.

This paper describes in vitro evaluation by Bacillus subtilis rec-assay and Salmonella-microsome assay of the genotoxic properties of some 1,2-benzisothiazole and 1,2-benzisothiazolin-3-one derivatives, containing groups (aromatic nitro, aromatic amino, epoxide groups) often associated with mutagenic properties and defined as "alerting groups". Compounds 2, 3, 4, 7, 8, 9, 11, 14, 16, 20, 21 and 22 exhibited DNA-damaging activity. The Salmonella-microsome assay confirmed the genotoxic activity of these compounds, which was also demonstrated for compounds 5, 6, 10, 12, 13, 15, 17, 18, 19, 25 and 27. Relationships between chemical structure and genotoxic activity showed that all the 1,2-benzisothiazole derivatives containing an alerting group were active. On the contrary, among 1,2-benzisothiazolin-3-one derivatives, compounds 24 and 26 were non-mutagenic, although an alerting group was present in the molecule.

Animals↗

CEOP regimen in the treatment of advanced low-grade non-Hodgkin's lymphomas: preliminary report.

Between March 1987 and December 1988, 30 previously untreated patients with low-grade non-Hodgkin's lymphomas (NHL), according to the Kiel classification, were treated by a combination of therapy including cyclophosphamide, epirubicin, vincristine, and prednisone (CEOP). Eighteen patients (60%) achieved a complete pathologic remission, and 8 patients (26.6%) had a partial response with a reduction of more than 50% of tumor-related manifestations. Four patients (13.4%) were primary resistant to CEOP. The overall survival was 96.6% with a median follow-up of 25 months from the diagnosis; none of the patients who achieved complete response relapsed at a median follow-up of 21 months from the completion of treatment. Clinical and hematologic toxicities were irrelevant. This regimen was effective in inducing a good remission rate of low-grade NHL, but a longer follow-up for definitive conclusions is warranted.

Adult↗

Phase II cooperative study with a new alkylating drug, PTT-119, in the treatment of non-Hodgkin's lymphomas.

In a phase II cooperative study involving eleven Italian haematological units, the efficacy and toxicity of a new alkylating compound, PTT-119, was evaluated in 53 patients with non-Hodgkin's lymphoma (NHL). Forty-five of the patients had been previously treated with various regimens of chemotherapy, the remaining eight were at the onset of the disease. PTT-119 was scheduled at 3.0 mg/kg every three weeks for a minimum of three administrations. Seven patients achieved a complete remission (CR), 19 a partial remission (PR); the overall response rate was 49%. The median duration of response was 6 months. Most frequent adverse effects were alopecia, nausea and vomiting and phlebitis due to the drug infusion. Myelosuppression was severe only in patients with bone marrow involvement or who were heavily pretreated. No liver, cardiac or renal toxicity was recorded. These data indicate that PTT-119 is an effective drug in the treatment of NHL; the matter of its non-cross-resistance with other alkylating compounds warrants further studies.

Adult↗

Alpha-2b recombinant interferon (Intron) in Hodgkin's lymphoma: therapeutic perspective.

In an ongoing phase II study we are evaluating the role of alpha-2b recombinant interferon in Hodgkin's disease; the study design includes patients with high-risk parameters who are treated by combination chemotherapy MOPP, ABVD, MOPP + ABVD or equivalent combinations. At the end of the therapeutic program which could include also radiotherapy, patients will be randomly assigned to receive alpha-2b interferon at 3 MU/day over 3 months and then 3 MU/three times/week over 9 months or no further treatment. Up to September 1989, 107 patients were randomized; evaluable patients with a minimum follow-up of 3 months are 95, 56 in the arm of interferon and 39 in the arm of no further treatment. The results are preliminary and differences could not be disclosed between the two arms concerning either the relapse rate or the incidence of infections. Tolerance and toxicity due to alpha-2b interferon in patients with Hodgkin's disease could be defined as acceptably good considering that mild and reversible hematological toxicity was experienced in 12 (21%) patients; objective clinical toxicity was recorded in 4 (7%) patients although 7 (12%) patients refused to continue the treatment. Definite conclusions will be drawn when 100 patients per arm become evaluable.

Adult↗