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Biomedical subjects

M Rizzi

Publications and source records attributed to M Rizzi.

At least 109 records · Page 6Linked to original sources
PubMed1986

Mean transit time, forced expiratory volume and age in healthy male smokers and non-smokers.

We studied 67 healthy males aged 20-30 years, 29 of them non-smokers and 38 smokers. In smokers, forced expiratory volume (FEV), 1 s forced expiratory volume (FEV1) and peak flow (PF) were significantly lower than in non-smokers, while the FEV1/FEV ratio, flows and mean transit time (MTT) compared well. MTT appeared directly related to age and negatively to FEV1/FEV, with no difference between the two groups, but MTT was directly related to FEV in non-smokers and negatively in smokers. Multiple regression analysis, MTT = a + b(FEV)+c(age), showed that parameters b and c were significantly different between smokers and non-smokers and, in the former, parameter b was negative. In non-smokers the effects of age and FEV on MTT were roughly the same, but in smokers MTT was influenced above all by age, probably because MTT measured the effects of continued smoking.

Adult↗
PubMed1984

Immune response in a symptomatic case of Tetrapetalonema perstans infection.

The immune response in a 49-year-old Italian nun affected by Tetrapetalomena (Dipetalonema) perstans following an eight-year stay in Cameroon is reported. On admission the patient presented with polyarthralgia, conjunctival pruritus and irritation, oedema of the limbs, generalized itching, hypereosinophilia and low total IgE titre. During diethylcarbamazine treatment and, subsequently, during mebendazole administration, an exacerbation of her symptoms was observed. At the same time, activation of the alternative complement pathway and the appearance of circulating immune complexes were noted, suggesting a type III hypersensitivity reaction. Circulating immune complexes and diethylcarbamazine-induced release of parasitic antigens may also be considered responsible for the decrease of OKT3 and OKT4 positive lymphocytes.

Antibody Formation↗
PubMed1981

[Experience with intravenous amiodarone in hyperkinetic supraventricular arrhythmias].

The Authors tested the effectiveness of amiodarone hydrochloride i.v. in 50 cases of supraventricular hyperkinetic arrhythmias recently aroused. 50 patients, aged 41 to 85 years, with paroxysmal supraventricular tachycardia (PSVT, 21 cases), atrial flutter (7 cases) or fibrillation (22 cases) were treated with 4 mg/Kg of body weight of amiodarone i.v. over 2 min., followed by other 1500 mg/24 hours over 48 hours while amiodarone per os was started for antiarrhythmic prophylaxis; a 12 leads surface ECG and blood pressure were periodically recorded. The sinus rhythm was restored within 3 hours in every case of PSVT (100% of success), within 30 hours in 19 cases of atrial fibrillation (86% of success) and in 5 cases of atrial flutter (71% of success). A slowing down of ventricular frequency ranging from 15 to 40% occurred within 10 min. in case of failure of restoration of sinus rhythm; a slight and transient lengthening of P-R occurred in 1 case; no particular side effects nor noteworthy changes of blood pressure were observed. Amiodarone i.v. proved to be a very effective remedy, handy and well tolerated for the arrhythmias considered above.

Adult↗
PubMed1979

Effect of whole body irradiation on different tissues. Experiments with 14C leucine in the rat.

The uptake and elimination of 14C leucine were analysed in controls and in rats irradiated 2 h before injection with 8 Gy whole-body irradiation. Plasma, small intestine, kidney and skin were assayed after homogenization for TCA soluble activity curves. In highly differentiated tissues with poor proliferative activity and low protein turnover, the uptake and elimination of the tracer did not appear to be affected by irradiation. In the small intestine differences between control and irradiated animals seemed significant.

Animals↗
PubMed1979

Post-irradiation enzyme activities of the rat small intestine: effects on circadian fluctuations.

The effects of ionizing radiations on circadian fluctuations in the activities of small bowel mucosal enzymes were studied. The fluctuations in activities of brush-border enzymes disappeared after irradiation coincidentally with changes in their activity. This change was particularly pronounced with leucinaminopeptidase. At longer periods after irradiation (50 and 74 hours) when the whole epithelium showed morphological changes, the activity of brush-border enzymes was very low. The activity of lysosomal enzymes (which do not show circadian fluctuations) increased when the epithelium showed marked morphological modifications and the stroma contained numerous inflammatory cells.

Animals↗
PubMed1976

[Contribution toward determining the inner equilibrium of the spinal column (pivotal point as temporary pole) (author's transl)].

The estimation of the centre of rotation of a spine segment can be shown as a transient pole, which follows the polar curve of the movement of the upper segment of the spine, relative to the lower one. With the help of X-ray, it is possible to evaluate two separate positions of the pole, from the normal position to the medium flexion and from the medium to the extreme flexion of the lumbal segment. Based on these expected values, as well as their intervals, pathological cases can be recognized, which is also shown in an example.

Biomechanical Phenomena↗
PubMedDate not supplied

Crystal structure of the bovine alpha-chymotrypsin:Kunitz inhibitor complex. An example of multiple protein:protein recognition sites.

The crystal structure of bovine alpha-chymotrypsin (alpha-CHT) in complex with the bovine basic pancreatic trypsin inhibitor (BPTI) has been solved and refined at 2.8 A resolution (R-factor = 0.18). The proteinase:inhibitor complex forms a compact dimer (two alpha-CHT and two BPTI molecules), which may be stabilized by surface-bound sulphate ions, in the crystalline state. Each BPTI molecule, at opposite ends, is contacting both proteinase molecules in the dimer, through the reactive site loop and through residues next to the inhibitor's C-terminal region. Specific recognition between alpha-CHT and BPTI occurs at the (re)active site interface according to structural rules inferred from the analysis of homologous serine proteinase:inhibitor complexes. Lys15, the P1 residue of BPTI, however, does not occupy the alpha-CHT S1 specificity pocket, being hydrogen bonded to backbone atoms of the enzyme surface residues Gly216 and Ser217.

Animals↗
PubMedDate not supplied

Cardiac and pulmonary effects of alpha tumor necrosis factor administered by isolation perfusion.

AIMS: We studied cardiac and pulmonary function in 22 patients affected by in transit metastases from cutaneous melanoma and metastases from soft tissue sarcoma of the limbs and treated with isolation perfusion in extracorporeal circulation with rTNF alpha at doses ranging from 0.5 to 4 mg/m2 in mild hyperthermia. PATIENTS AND METHODS: All patients experienced a septic-like shock syndrome of variable severity: this feature lasted from 24 to 72 h and was controlled by the infusion of dopamine. Seventeen patients suffered from respiratory insufficiency, which required assisted ventilation (7 cases mechanical ventilation for 1 day, 8 cases for 2 days, and 2 cases synchronized intermittent mandatory ventilation). RESULTS: Spirometric parameters recorded 7-15 days after treatment did not change from baseline values. In contrast, lung transfer factor for carbon monoxide significantly declined in a dose dependent fashion. CONCLUSIONS: Our data confirm that rTNF alpha administered by isolation perfusion technique induces systemic cardiovascular and pulmonary side effects. Further studies are required to better define time course and reversibility of impaired pulmonary function.

Adult↗
PubMedDate not supplied

Isolated pelvic perfusion for the treatment of unresectable primary or recurrent rectal cancer.

Between May 1990 and December 1995, 16 patients with primary or recurrent unresectable rectal cancer were treated by isolated pelvic perfusion. All patients had been previously treated and were considered unsuitable for surgery or further systemic chemotherapy or radiotherapy. The treatment was based on a perfusion lasting 90 min at 40.5 C degrees with 5-fluorouracil, mitomycin-C and mitoxantrone. Whenever technically feasible (10 cases), continuous intraarterial chemotherapy (through a Medtronic device with a catheter in the inferior mesenteric artery) was administered postoperatively. Two complete responses and 2 partial responses were observed; 8 other patients showed stable disease. One patient did not show any response. Finally, 3 patients for various reasons were not assessable. All patients experienced immediate relief of pain. No major side effects directly related to isolated pelvic perfusion were recorded; a transitory bone marrow depletion was observed in all cases. In conclusion, isolated pelvic perfusion is useful in inoperable disease of the pelvis by reliably relieving pain and thereby improving the patients quality of life.

Adult↗
PubMedDate not supplied

3-D surface profile analysis: different finishing methods for resin composites.

A microfilled and hybrid resin composites used for esthetic restoration were finished and polished using four methods: Enhance system, Sof-Lex system, Multi-step system and Identoflex points. The tested materials were condensed into cylindrical molds, covered with a Mylar matrix at the surface to be tested and incrementally cured according to manufacturers' instructions. Samples were randomized into four groups of three for each material and were finished/polished using the different methods. The samples were then analyzed by a 3-D surface profiler to obtain roughness average (Ra), root mean square value (rms), greatest distance peak-valley (PV), measure of profile about the center line (Rsk) and measure of steepness of the amplitude density curve of the roughness profile (Rku) directly from the tested area. This method offers the advantage of being error-free. All parameters were determined for each sample and the mean of each parameter was determined for each group. ANOVA and Sheffé's test were employed to determine whether significant differences existed. The Enhance and Multi-step systems gave the best finish and polish for both materials.

Analysis of Variance↗
PubMedDate not supplied

Copper resinate: preparation, characterisation and study of degradation.

This paper describes a method for the synthesis of Copper Resinate, which disappeared from artists' palettes in the eighteenth century. This was carried out by interpreting ancient recipes following a scientific approach. Its characterisation using Fourier Transform-Infrared Spectrometry and Gas Chromatography-Mass Spectrometry demonstrated that it is a mixture containing copper and oxidised abietic acids, mainly dehydroabietic and 7-oxo-dehydroabietic acids, formed during the preparation of the pigment and the curing of the paint layer. The composition of copper resinate paint layers, artificially aged by U.V. irradiation at 365 nm (UV), heating (T), and exposed to atmospheric pollutants (NOX) in a climatic chamber, was investigated. The combination of irradiation and temperature produced a change in colour along with a significant increase in the recovered amount of 7-oxo-dehydroabietic acid. The identification of copper resinate in a sample from an old painting should be related to the presence of the following resin compounds which are stable in the ageing process: dehydroabietic and 7-oxo-dehydroabietic acid pimaradienic acids. Photo-oxidation of the resin acids co-ordinated with copper seem to be the most probable decay mechanism responsible for the colour change in the pigment.

Abietanes↗
PubMedDate not supplied

Hypersomnolence in fibromyalgia syndrome.

OBJECTIVE: To evaluate hypersomnolence in patients affected by fibromyalgia syndrome. METHODS: Thirty consecutive patients affected by fibromyalgia syndrome (FMS) (28 F) completed a sleep questionnaire and underwent the following evaluations: lung function tests; polysomnography; the Epworth sleepiness scale (ESS), which measures sleep complaints and daytime hypersomnolence; and the visual analogical scale (VAS) to detect subjective pain, fatigue, anxiety and depression. RESULTS: The FMS patients were divided into two groups based on their ESS score. Patients complaining of daytime hypersomnolence had a higher number of tender points (15 +/- 2 vs. 12 +/- 1, p < 0.01), a higher subjective pain score (72 +/- 15 vs. 52 +/- 13, p < 0.05), and more fatigue (p < 0.05). The diffusing capacity of the lung (Tlco) was more impaired and the occurrence of periodic breathing was higher. FMS patients complaining of daytime somnolence had significantly less efficient sleep than the FMS patients with no daytime somnolence (p < 0.05), i.e. a lower proportion of stage 3 sleep (5 +/- 2% vs. 12 +/- 3%; p < 0.001), stage 4 sleep (1 +/- 0.5% vs. 4 +/- 1%; p < 0.001), and twice as many arousals per hour of sleep (p < 0.01). The respiratory pattern of FMS patients with hypersomnolence showed a higher occurrence of periodic breathing (p < 0.05). The short length of apneas and hypopnoeas did not affect the apnea/hypopnea index (5.1 +/- 3 vs. 7 +/- 4; ns), but FMS patients with daytime hypersomnolence had a greater number of desaturations per hour of sleep (11 +/- 6 vs. 6 +/- 5; p < 0.05). Pulmonary volumes did not differ between the two groups. The EES score was significantly correlated in FMS patients, and even more markedly in the FMS patients with hypersomnolence, TLco, A/I, and disease duration. The ESS score was correlated significantly with the number of tender points only in FMS patients with daytime hypersomnolence. CONCLUSION: The occurrence of daytime hypersomnolence in FMS patients is linked to a greater severity of fibromyalgia symptoms and to more severe polysomnographic alterations.

Adult↗
PubMedDate not supplied

Salpingoscopy in patients with endometriosis-associated infertility.

Endoscopic evaluation of the tubal mucosa has been shown to be an important prognostic factor in predicting the probability of a subsequent intrauterine pregnancy. A recent classification of the tubal mucosa lesions allows uniformity of evaluation, permitting comparison of results in prospective studies. It has been suggested that endometriosis may be associated with intratubal abnormalities. In this prospective study we evaluated 35 patients with endometriosis-associated infertility. No intraluminal abnormalities were found, and all the patients that subsequently conceived had an intrauterine pregnancy.

Adult↗
PubMedDate not supplied

[Rectal burns caused by enema].

The injuries incident to enemas may vary from oedema of the mucosa to gangrene of the large bowel. The burn of the rectum is very rare, and in mild cases it has an identical course to that of the caustic oesophagitis. The place of corticosteroids, administered by intravenous route or topically, in the therapy of te burn of the rectum is unproven. Healing of the lesion occurs by fibrosis and may result in structure formation, which usually need a treatment only when obstructive symptoms develops.

Bisacodyl↗