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Biomedical subjects

M Fontana

Publications and source records attributed to M Fontana.

At least 109 records · Page 6Linked to original sources

[Hydrological therapy of renal lithiasis].

The spa treatment most widely used in the management of renal calculosis is the drinking of a certain amount of mineral water under certain predetermined conditions of temperature, time and rhythm. These treatments are always indicated unless there are obstacles to the passage of urine or general contraindications. Chances for success are increased if the diagnosis is exact and the stone has been located. The results obtained by various authors are reported and their statistical validity is discussed. Favorable effects consist in: increased diuresis with urine dilution and correspondingly reduced concentration of lithogenic salts and hence supersaturation of urine; reduced concentration of microorganisms; changes in the physiological condition of the renal medulla; changes in inhibitors of crystallization, in urinary pH; mechanical effect on the urinary passages; increased ureter motility; expulsion of small stones and sand; preventive action on recurrences after surgery and after extra-corporeal shock-wave treatment, percutaneous therapy and uretero-nephroscopy.

Diuresis↗

Primary chemotherapy and delayed surgery (neoadjuvant chemotherapy) for telangiectatic osteogenic sarcoma of the extremities.

Twelve patients with telangiectatic osteogenic sarcoma (TOS) of the extremities were treated with neoadjuvant chemotherapy, according to two different protocols. Preoperatively the patients received high-dose methotrexate(HD-MTX)/cisplatinum(CPD) or HD-MTX/CPD/adriamycin(ADM). CPD was delivered intra-arterially, the other drugs intravenously. Limb salvage surgery was performed in eight instances and four patients underwent amputation. Post operative chemotherapy was tailored according to the grade of necrosis determined by preoperative treatment on the primary tumor. In ten cases (83%) the grade of necrosis resulted higher than 95%. The mean length of follow-up was 3.5 years with a range of 18 to 72 months. Ten patients (83%) remained continuously disease-free, while two patients developed lung metastases and died of uncontrolled disease. No local recurrences were observed. These results are better than those observed in 167 contemporary cases of conventional osteosarcoma treated with the same protocols. This study confirms that TOS is not always a lethal tumor as suggested by prior reports. Employing neoadjuvant chemotherapy a high percentage of patients with TOS can be cured and in most of them, limb sparing surgery is possible and safe.

Adolescent↗

Bowel frequency in healthy children.

Bowel frequency was recorded, on a diary sheet basis, in 662 children from six Italian cities. There is a wide interindividual variability, showing a sharp decrease with age; we report the distribution of the percentiles in the different age groups. Among infants, the breast-fed ones pass significantly more stools than the formula-fed.

Child↗

Heat stable enterotoxin produced by Escherichia coli in acute diarrhoea.

We screened 569 children with acute onset diarrhoea from five Italian towns for heat stable enterotoxin produced by Escherichia coli. We compared an enzyme linked immunoabsorbent assay (ELISA) with the standard suckling mouse assay for detection of the enterotoxin. A total of 31 (5.4%) children were found who had strains of E coli that produced heat stable enterotoxin: 26 strains were positive in both tests, four only in the suckling mouse assay, and one only in the ELISA. Compared with the suckling mouse assay the sensitivity of the ELISA was 87% and the specificity was 99.8%. The mean age of the children with E coli that produced heat stable enterotoxin was 22 months. Fifteen (48%) of the children had ingested potentially contaminated food and five (17%) had a previous contact with someone with diarrhoea. The clinical picture was milder than that described in developing countries. Faecal osmolality and the osmolal gap were consistent with a secretory diarrhoea in 12 out of 15 (80%) of these children. The mean duration of the diarrhoea was five days. Heat stable enterotoxin produced by E coli is a common cause of mild diarrhoeal illness in Italian children.

Adolescent↗

[Retrospective analysis of 31 cases of soft tissue tumors. Comparison of MR and surgical and anatomo-pathological findings].

Twenty-five patients (16 with malignant soft-tissue tumors and 9 with suspected recurrence), previously studied with conventional radiography and Computed Tomography (CT), were examined with Magnetic Resonance (MR) imaging. MR findings were surgically and anatomo-histopathologically confirmed. Six more patients with benign lesions were examined for differential diagnosis. MR capabilities are here evaluated to detect and eventually characterize the lesion, and to assess its exact location. No false positives were found, and there was only one false negative, in a case of recurrent Malignant Fibrous Histiocytoma (MFH). In another case of MFH the infiltration of the adjacent vessels and nerves was not imaged. After a careful review of all the examinations, MR imaging appears to be able to provide much information for surgical planning about tumor extent and margins, thanks to its contrast resolution between tumor and surrounding anatomical structures. Therefore, MR imaging can be reasonably employed as the examination of choice when a soft-tissue tumor is clinically suspected, because of the multi-planar images it provides with and of its differential imaging parameters.

Adolescent↗

The results of reconstruction of the anterior cruciate ligament with semitendinosus and gracilis tendons in chronic laxity of the knee.

The authors report the medium term results (41 months) in 88 patients submitted to surgery for reconstruction of the anterior cruciate ligament according to the method currently in use at our Clinic which uses the semitendinosus and gracilis tendons. The results were evaluated according to a score card method and in 28 patients a KT-1000 arthrometer was also used. The method gives a probability of full success in approximately 85% of cases, with significantly better results in patients not submitted to meniscectomy. A comparison with other methods of autogenous transplant and prosthetic substitution, even on the basis of the data provided by the KT-1000, still places the semitendinosus and gracilis method at the forefront.

Consumer Behavior↗

The effectiveness of chemotherapy in localized malignant fibrous histiocytoma (MFH) of bone: the Rizzoli Institute experience with 66 patients treated with surgery alone or surgery + adjuvant or neoadjuvant chemotherapy.

Between January, 1974 and July, 1985 66 patients with non-metastatic malignant fibrous histiocytoma (MFH) of bone in the estremities were surgically treated with amputation (34 cases) or resection (32 cases) according to the extension of the tumor. With the exception of 3 patients, who had severe medical contraindications to the chemotherapeutic drugs, all the patients were offered, in addition to the surgery, adjuvant chemotherapy (patients treated before 1983) or neoadjuvant chemotherapy (patients treated after 1983). 33 patients accepted, while 30 wanted to be treated with surgery alone. At median follow-up of 7 years (3-14) 25 patients remained continuously disease-free and 41 relapsed (27 with metastatic disease, 1 with local recurrence and 13 with both metastases and local recurrence). The percentage of patients who remained continuously disease-free was 12.1% (4:33) in the group of patients treated with surgery alone and 63.5% (21:33) in the group treated with surgery plus adjuvant or neoadjuvant chemotherapy. Although the two groups of patients were not completely superimposable (the patients treated with surgery alone were older and more often the MFH arose in pre-existing bone lesions) these results seem to suggest the usefulness of adjuvant and neoadjuvant chemotherapy for this tumor.

Adolescent↗

Fecal alpha-1-antitrypsin excretion in acute diarrhea: relationship with causative pathogens.

Concentrations of alpha-1-antitrypsin (AT) in random fecal samples from 68 infants (92.7% outpatients) with acute diarrhea and 32 healthy controls were determined. The mean +/- s.d. for AT in infants with diarrhea was 2.07 +/- 1.88 mg/g dry stool (mg/g d.s.) compared with 1.29 +/- 0.72 mg/g d.s. (p less than 0.05) in controls. Fecal AT was significantly greater than that of the controls only for diarrhea caused by Rotavirus or Salmonella. Salmonella patients also had significantly higher fecal levels of AT than patients with diarrhea caused by Campylobacter. Fifty percent of the infants with Salmonella infections excreted more than 2.73 mg/g d.s. AT, which is above the control mean + 2 s.d. Fecal excretion of AT was highest in patients with macroscopic intestinal bleeding, but it still depended more on the causative agent than on bleeding per se. This finding of increased intestinal protein loss during acute diarrhea, even in the less severe diseases, emphasizes the necessity to rapidly restart adequate nutritional intake.

Acute Disease↗

Late multifocal gliomas in adolescents previously treated for acute lymphoblastic leukemia.

Three of 37 adolescents in long-term remission from childhood acute lymphoblastic leukemia (ALL) developed malignant multifocal gliomas several years after completing treatment that included central nervous system (CNS) prophylaxis with radiation (RT) and intrathecal methotrexate (IT-MTX). No recurrence of the leukemia was evident when the CNS tumors were discovered. Seventeen other similar cases have been recorded. The occurrence of second malignancies is reviewed in the context of this development and of the oncogenic effects of radiation. It is probable that prolonged exposure to IT-MTX may have had a synergistic effect with radiation in contributing to the unusual incidence of glial tumors in these patients.

Adolescent↗

Simple clinical score and laboratory-based method to predict bacterial etiology of acute diarrhea in childhood.

We describe a two-step predictive method to assess the probability of bacterial etiology in cases of diarrhea. The patients are divided into three probability groups (high, intermediate, low) according to a clinical score. Thereafter the patients in the intermediate group are further assigned to the high or low probability group according to the presence or absence of fecal leukocytes. We developed the method in an initial series of 157 children with acute diarrhea; the reproducibility of the method was tested in a second series of 180 cases. Eighty-six percent of patients in the first series and 81% in the second were correctly classified by our method. We suggest its use, especially in pediatric practice, to identify children with the highest probability of bacterial diarrhea, thus reserving stool culture to a few selected cases because only a minority of children with diarrhea have a recognized bacterial etiology.

Adolescent↗

Transamination of L-cystathionine and related compounds by a bovine liver enzyme. Possible identification with glutamine transaminase.

A transaminase which catalyses the monodeamination of L-cystathionine was purified 1100-fold with a yield of 15% from bovine liver. The monoketoderivative of cystathionine spontaneously produces the cyclic ketimine. Other sulfur-containing amino acids related to cystathionine such as cystine, lanthionine and aminoethylcysteine were also substrates for the enzyme. The relative molecular mass of the enzyme was determined to be 94 000 with a probable dimeric structure formed of identical subunits. The isoelectric point of the enzyme was at pH 5.0 and the maximal enzymatic activity was found at pH 9.0--9.2. Kinetic parameters for cystathionine and for the other sulfur amino acids as well as for some alpha-keto acids were also determined. Among the natural amino acids tested, glutamine, methionine and histidine were the best amino donors. The enzyme exhibited maximal activity toward phenylpyruvate and alpha-keto-gamma-methiolbutyrate as amino acceptors. The broad specificity of the enzyme leads us to infer that the cystathionine transaminase is very similar or identical to glutamine transaminase.

Amino Acids↗

Modification by fluoangiography of color vision in diabetic patients.

Fluoangiography causes in diabetics a temporary increase of the number of errors when reading Birch and SPP II pseudoisochromatic plates, especially in case of macular edema and for tritan plates. Other experiments show that this change is more due to an increased filter effect by the fluorescein accumulation than to the increase of glare by the flashes for photography. Measurements of the foveal spectral increment threshold sensitivity curves does not show impairment of the blue mechanism by fluoangiography; on the contrary the green and red mechanisms become less sensitive.

Biomechanical Phenomena↗