Biomedical subjects

M Rossi

Publications and source records attributed to M Rossi.

At least 361 records · Page 20Linked to original sources

PubMed1995

Esophageal achalasia: laparoscopic versus conventional open Heller-Dor operation.

BACKGROUND: The laparoscopic treatment of esophageal achalasia has recently been introduced, and the occasional reports in the literature seem to indicate considerable advantages for patients in terms of surgical trauma, postoperative discomfort, and appearance. As yet, however, no studies have directly analyzed the benefits and shortcomings of the new surgical technique by comparison with the conventional open procedure. The objective of our study was to review recent experience with the laparoscopic Heller-Dor operation (LAP-HD) at the Department of Surgery of Padua University and compare it with the traditional open Heller-Dor procedure (OPEN-HD) to assess early effectiveness in patients with primary esophageal achalasia. PATIENTS AND METHODS: The records of 17 patients who had LAP-HD and a matched group of 17 patients who had OPEN-HD were retrospectively reviewed. The duration of procedures, morbidity, several aspects of the postoperative course, and hospital costs were recorded and compared. Results of clinical follow-up and of manometric and pH-monitoring studies performed 6 months postoperatively were also evaluated in both patient groups. RESULTS: LAP-HD took longer than OPEN-HD (mean 178 versus 125 minutes). There was no mortality or major morbidity in either group. Postoperative pain and ileus and need for IV nutrition lasted a shorter time for LAP-HD patients (P < 0.0001). Consequently, the median postoperative hospital stay and the median interval before returning to normal activity were also shorter (4 and 14 days for the LAP-HD group versus 10 and 30 days for the OPEN-HD group, P < 0.0001). During follow-up, dysphagia recurred in 1 patient of the LAP-HD group and gastroesophageal reflux was registered in 1 patient of the OPEN-HD group. Lower esophageal sphincter pressure decreased significantly after both procedures. CONCLUSIONS: Laparoscopic management of achalasia leads to short-term results comparable to those of the well-established open technique. In view of the less severe surgical trauma and lower hospital cost, the laparoscopic approach is preferable, but long-term studies are needed.

Adult↗

PubMed1995

The lactase persistence/non-persistence polymorphism is controlled by a cis-acting element.

Lactase activity is present at high levels in the small intestine of some human adults and not others. This is due to a genetically determined polymorphism which affects the developmental regulation of the expression of the lactase gene. This polymorphism is of considerable interest in relation to cultural differences in nutrition but despite exhaustive studies, the molecular basis has not yet been found. It has not even been shown whether the sequence differences reside within or adjacent to the lactase gene itself or in a trans-acting factor. We have therefore exploited known DNA 'marker' polymorphisms within the exons of the lactase gene to examine the expression of the individual lactase mRNA transcripts from persistent and non-persistent individuals in order to determine whether the regulation is in cis or trans. Our results show that in certain lactase persistent individuals one allele of the lactase gene is expressed at much lower levels than the other and these individuals tend to have intermediate lactase activities. It is proposed that these people are heterozygous for the lactase persistence and non-persistence alleles and that this means that the nucleotide substitutions responsible for the lactase persistence/non-persistence polymorphism are cis-acting. This narrows down considerably the area of the genome that needs to be searched for the relevant sequence differences.

Adult↗

PubMed1995

A gene encoding a putative membrane protein homologous to the major facilitator superfamily of transporters maps upstream of the beta-glycosidase gene in the archaeon Sulfolobus solfataricus.

We have identified a gene encoding a putative membrane protein homologous to the major facilitator superfamily, mapping upstream of the lacS gene in Sulfolobus solfataricus. Permeases from this family mediate secondary transport and are widely distributed among eubacteria and eukaryotes; the finding of an archaeal member suggests that this mechanism of transport evolved before the divergence of the three living domains. We also report a transcriptional mapping of the gene cluster.

Amino Acid Sequence↗

PubMed1995

Radiolabelled lymphocyte migration in rheumatoid synovitis.

OBJECTIVES: To study the ability of technetium-99m hexamethyl propylene amineoxime (HMPAO) labelled lymphocyte scintigraphy to quantify synovial inflammation, and to analyse the kinetics of lymphocyte retention in the joints of patients with rheumatoid arthritis (RA). METHODS: After isolation of the lymphocytes, the cells were radiolabelled in vitro with 250 MBq 99mTc-HMPAO. The scans were performed 30 minutes, three hours and 20 hours after injection. RESULTS: An increase of the scintigram signal obtained at 20 hours was associated with a high joint swelling and joint pain score (F test = 3.07, p < 0.002), but not with the radiological score. A positive joint scintigram was predictive of active synovitis. Although the scintigram variation over time did not reach statistical significance, the kinetics of the scintigram signal tended to differ according to the disease duration: in early RA, active arthritis could be clearly imaged as early as 30 minutes, increased at three hours and the signal intensity persisted at 20 hours. In contrast, in long standing disease, the affected joints were imaged at 30 minutes, persisted unchanged at three hours, and the scintigram score decreased significantly at 20 hours. CONCLUSIONS: The study shows that 99mTc-HMPAO joint scintigraphy may be used to detect and to localise active rheumatoid arthritis.

Aged↗

PubMed1995

Secondary alcohol metabolites mediate iron delocalization in cytosolic fractions of myocardial biopsies exposed to anticancer anthracyclines. Novel linkage between anthracycline metabolism and iron-induced cardiotoxicity.

The cardiotoxicity of doxorubicin (DOX) and other quinone-containing antitumor anthracyclines has been tentatively attributed to the formation of drug semiquinones which generate superoxide anion and reduce ferritin-bound Fe(III), favoring the release of Fe(II) and its subsequent involvement in free radical reactions. In the present study NADPH- and DOX-supplemented cytosolic fractions from human myocardial biopsies are shown to support a two-step reaction favoring an alternative mechanism of Fe(II) mobilization. The first step is an enzymatic two-electron reduction of the C-13 carbonyl group in the side chain of DOX, yielding a secondary alcohol metabolite which is called doxorubicinol (3.9 +/- 0.4 nmoles/mg protein per 4 h, mean +/- SEM). The second step is a nonenzymatic and superoxide anion-independent redox coupling of a large fraction of doxorubicinol (3.2 +/- 0.4 nmol/mg protein per 4 h) with Fe(III)-binding proteins distinct from ferritin, regenerating stoichiometric amounts of DOX, and mobilizing a twofold excess of Fe(II) ions (6.1 +/- 0.7 nmol/mg protein per 4 h). The formation of secondary alcohol metabolites decreases significantly (Pi < 0.01) when DOX is replaced by less cardiotoxic anthracyclines such as daunorubicin, 4'-epi DOX, and 4-demethoxy daunorubicin (2.1 +/- 0.1, 1.2 +/- 0.2, and 0.6 +/- 0.2 nmol/mg protein per 4 h, respectively). Therefore, daunorubicin, 4'-epi DOX, and 4-demethoxy daunorubicin are significantly (P < 0.01) less effective than DOX in mobilizing Fe(II) (3.5 +/- 0.1, 1.8 +/- 0.2, and 0.9 +/- 0.3 nmol/mg protein per 4 h, respectively). These results highlight the formation of secondary alcohol metabolites and the availability of nonferritin sources of Fe(III) as novel and critical determinants of Fe(II) delocalization and cardiac damage by structurally distinct anthracyclines, thus providing alternative routes to the design of cardioprotectants for anthracycline-treated patients.

Alcohols↗

PubMed1995

Growth hormone response to growth hormone-releasing hormone (GHRH), insulin, clonidine and arginine after GHRH pretreatment in obese children: evidence of somatostatin increase?

To clarify the possible neuroendocrine mechanisms underlying the impairment in growth hormone (GH) secretion present in obesity, the GH response to GH-releasing hormone (GHRH, N = 6), insulin hypoglycemia (N = 6), clonidine (N = 7) and arginine (N = 8) after GHRH pretreatment (1 microgram/kg iv 2 h before the tests) was evaluated in 27 obese peripubertal children and in a group of normal-weight short-normal children (N = 26). Growth hormone-releasing hormone pretreatment and all further stimuli elicited a statistically significant GH response in both obese and short-normal children; in the latter group arginine did not induce a significant GH response. No differences were found among the GH responses after the second stimuli in obese children, while in short-normal children the arginine peak and area values were lower than after GHRH and clonidine. Comparison between the two groups showed similar baseline but higher stimulated GH levels in normal-weight children after all tests except arginine, after which no difference was present. In conclusion, the neuroregulation of GH release seems to be similar qualitatively in normal-weight and obese youngsters; the different behavior observed after arginine, which is supposed to act through somatostatin inhibition, might be due to a chronic increase in somatostatinergic tone responsible for the lower stimulated GH levels in obesity.

Adolescent↗

PubMed1995

Sequence of Asr2, a member of a gene family from Lycopersicon esculentum encoding chromosomal proteins: homology to an intron of the polygalacturonase gene.

Asr is a family of genes regulated by abscisic acid, stress and ripening in tomato. Asr2, a recently reported member of this family, has been further characterized through sequencing of a genomic clone. We report the sequencing of 2029 bp of Asr2, spanning its AT-rich (62%) upstream region with probable regulatory functions. This region displays several candidate TATA and CAAT boxes that might be involved in transcription initiation, as well as a motif similar to one previously reported to be responsible for induction by ABA. Apart from that, we found a 108-bp stretch from the 3' non-coding region which displays a high homology (92%) to a region within intron 6 of the polygalacturonase gene, which, like Asr2, is expressed in ripening tomato fruit. This striking similarity suggests the presence of either a conserved regulatory motif or an abundant mobile element.

Base Sequence↗

PubMed1995

Changes in some egg components and analytical values due to hen age.

The influence of hen age on some egg characteristics was studied. Two commercial breeds of brown hens, namely Warren and Hy-Line, were considered at seven different ages. The variables analyzed were the weights of yolk and thick and thin albumen, pH, and the concentration of glucose, uridine, and uric and pyroglutamic acids of separated yolk and albumen. Albumen and yolk average weights and the proportion of yolk in the edible part of egg increased with hen age, whereas the average ratio of thick to thin albumen was not influenced by the progress of the laying cycle. Glucose, uridine, and uric acid were also not influenced by hen age. Pyroglutamic acid, which is detectable in yolk and not in the albumen of a fresh egg, showed a characteristic trend in yolk. Its concentration dramatically increased in the middle of the laying cycle and then decreased to values close to those observed in eggs of the young layers.

Aging↗

PubMed1995

[Nonvascular interventional radiology in the treatment of post-liver transplant complications. The clinico-radiological correlations and technical considerations].

Eleven patients, included in a series of 105 orthotopic liver transplant recipients, underwent interventional radiologic procedures for post-operative complications. Seven patients had obstructive jaundice, three patients had sepsis, and one patient was bleeding from the T-tube. Cholangiography, performed in 9/11 patients, demonstrated stenosis of the anastomosis in six cases, stenosis of the intrahepatic biliary tree in one case, and stenosis of both tracts in the remaining two cases. Four patients were treated with bilioplasty (from 1 to 5 sessions), using balloon catheters (8-10 mm) followed by stones removal in one case, and by the placement of a metallic stent in another case. The follow-up ranged from one to three years: no biliary stasis occurred, during that period, in these patients. Another patient with recurrent cholangiocarcinoma of the biliary anastomosis, treated with Carey-Coons endoprosthesis and brachytherapy, died four months later without jaundice. In the three patients with sepsis and in the patient with bleeding from the T-tube, intra- or extra-hepatic (in one case) multiple abscesses were demonstrated. The conservative treatment with the placement of percutaneous drainage catheters, associated with internal biliary drainage in two cases, allowed complete symptoms resolution. The technical success obtained in all patients confirmed the effectiveness of interventional radiology in the treatment of biliary complications after liver transplant, thus avoiding the need of surgical reintervention.

Cholangiography↗

PubMed1995

Multimedia presentation of lung sounds as a learning aid for medical students.

New educational technologies might help to compensate for the decrease in time and emphasis dedicated to physical examination in medical training. This may, in particular, be applicable for improving the skills in auscultation of the chest. We investigated whether a multimedia presentation of acoustic and graphic characteristics of lung sounds could improve the learning of pulmonary auscultation by medical students, in comparison with conventional teaching methods. We studied 48 medical students without clinical experience, who had received conventional formal teaching on chest examination. Chest auscultation skills were evaluated using an inaccuracy score for the student's auscultation report on three patients, selected according to a standardized procedure. After a baseline evaluation, 27 students in groups of 5-10, participated in a multimedia seminar on lung sounds during which digitized lung sounds were played and the corresponding time-expanded waveform and frequency spectrum were commented on and displayed on a computer. The remaining 21 students received conventional bedside training, acting as control group. The following week, all the students underwent a second evaluation of chest auscultation skills. No differences in the inaccuracy score were observed between the two groups in the preliminary test. However, in the second postintervention assessment, the inaccuracy score of the students who had followed the seminar (11.2 +/- 1.3 points) was significantly lower than that of the controls (16.6 +/- 1.6 points). The answers to a feedback questionnaire confirmed that the great majority of the students found the association of the acoustic signals with their visual image to be useful for learning and understanding lung sounds.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗

PubMed1995

[Laparoscopic treatment of hepatic cysts].

Laparoscopic treatment of simple hepatic cysts is reported. Recent indications to conservative surgical treatment for this benign disease are considered and different therapeutic options are analyzed. Surgical technique adopted in two cases observed is illustrated. In conclusion, the Authors consider laparoscopic treatment as an effective method for a mini-invasive surgical approach.

Aged↗

PubMed1995

The efficacy and safety of moguisteine in comparison with codeine phosphate in patients with chronic cough.

We conducted a multicentre, double-blind, parallel group study to compare the clinical efficacy of a new antitussive drug, moguisteine (100 mg t.i.d.), to that of a reference standard, codeine (15 and 30 mg, t.i.d.). Both drugs were given orally for a period of two days. A group of 119 patients (mean age 54 yrs; 61 females and 58 males) with chronic, dry or slightly productive cough, associated with various respiratory disorders (including chronic obstructive pulmonary disease, respiratory malignancies and pulmonary fibrosis) were enrolled at six participating centres. The percentage reduction in the number of morning coughs over a period of 6 h after the first administered dose compared to baseline assessment, was 21% with moguisteine (n = 39), 28% with codeine 15 mg (n = 38), and 29% with codeine 30 mg (n = 36). Differences between treatments were not significant. The percentage reduction in the number of nocturnal coughs per hour, after the last evening dose compared to baseline assessment, was 33, 46 and 52%, respectively. Subjective assessments (patients' visual analogue scale scores of cough frequency, cough intensity and sleep disturbance, and investigators' ranking of cough severity) indicated that there was a similar improvement in cough symptoms in all treatment groups. Adverse events were observed in two patients on moguisteine, three on codeine 15 mg, and five on codeine 30 mg. No event was serious, but discontinuation of treatment was required in two patients on codeine 30 mg. The results of our study suggest that moguisteine 100 mg t.i.d. is safe, and seems to have an antitussive activity similar to that of codeine 15-30 mg t.i.d.

Administration, Oral↗

PubMed1995

[Carcinomatous meningitis. Presentation of 3 cases].

Meningeal carcinomatosis is characterized by diffuse infiltration of the leptomeninges by metastatic cancer in patients usually with a previous history of malignancy. Primary tumors are adenocarcinomas of the breast or lung, or malignant melanoma. The clinical presentation is pleomorphic and commonly affects the cerebral hemispheres, the cranial nerves, or spinal cord and its roots. Diagnosis is confirmed by the presence of the malignant cells in the cerebrospinal fluid (CSF). Computed tomography (CT) and magnetic resonance (MRI) show abnormal findings including ventricular dilatation and small enhancing lesions along the CSF space. Despite radiotherapy and chemotherapy, vital prognosis remains bad and the treatment is useful in improving the quality of life. Three cases presented here emphasize once again the important fact that meningeal carcinomatosis remains a very difficult diagnosis; several lumbar punctures were sometimes necessary, and cerebral fluid studies cannot yet be replaced by other diagnostic techniques like contrast enhanced CT or MRI with gadolinium.

Adenocarcinoma↗

PubMed1995

[Laparoscopic cholecystectomy in pregnancy].

After appendicectomy, cholecystectomy is the most frequently nongynecological operation performed in pregnant women. Pregnancy has been stated to be a contraindication to laparoscopic cholecystectomy (LC) because of the unknown effects of a prolonged CO2 pneumoperitoneum on the fetus. Between September 1990 and December 1993 451 patients underwent LC at the 2nd Surgical Department of the University of Padova-Italy. Two patients were operated during the second trimester of pregnancy. LC without cholangiograms was successful in both patients and uncomplicated term delivery occurred. The Authors conclude that pregnancy is not a contraindication to LC; it can be performed safely during pregnancy and should be scheduled during the second trimester.

Acute Disease↗

PubMed1995

[Ultrasonic evaluation of early atherosclerotic damage in patients with type 1 diabetes mellitus].

UNLABELLED: The aim of this study was to evaluate the influence of metabolic control on the development of atherosclerotic lesions in type 1 insulin-dependent diabetic patients (IDDM). MATERIALS AND METHODS: Twenty-eight well controlled IDDM patients, without known risk factors or clinical evidence of cardiovascular disease, together with 28 age-matched healthy controls spontaneously underwent high-resolution echographic evaluation of carotid femoral arteries. A global score of atherosclerotic damage as been assigned to the four investigated vessels on the basis of 1-6 scale, which takes into account most important ultrasound atherosclerotic lesion found in every artery. RESULTS: Diabetic and healthy controls differed significantly as regard to medio-intimal carotid thickness (p < 0.001), but were similar as for score of atherosclerotic damage. CONCLUSIONS: Our results suggest that, in spite of a carotid wall medio-intimal thickness more pronounced in IDDM patients, well controlled IDDM is associated with atherosclerotic damage almost identical to that of healthy age-matched controls.

Adolescent↗

PubMed1995

Industrial-scale production and rapid purification of an archaeal beta-glycosidase expressed in Saccharomyces cerevisiae.

The application of enzymes isolated from extreme thermophiles in biotechnological processes is hampered by their unconventional fermentation conditions. The expression, in mesophilic hosts, of genes encoding for thermophilic proteins enables these difficulties to be overcome and permits the production of enzymes in high yield by using conventional fermentation plants and an efficient enzyme purification utilizing heat precipitation of host proteins. The beta-glycosidase gene from Sulfolobus solfataricus, a thermoacidophilic archaeon growing at 87 degrees C and pH 3.5, has been cloned and expressed in Saccharomyces cerevisiae (baker's yeast). The fermentation of a S. cerevisiae strain on a 100-litre scale and the two-step purification of the expressed beta-glycosidase by cell autolysis and extracts thermal precipitation is described. This procedure, after 72 h of autolysis, gave a yield 56-fold higher with respect to that obtained with the beta-glycosidase from S. solfataricus.

Biotechnology↗

PubMed1995

Cognitive design for sharing medical knowledge models.

By building a medical conceptual model inside the galen project, a methodology has been defined to deal with both operative goals and deep and unsolved problems about knowledge. This knowledge sharing oriented approach exploits existing medical coding systems such as knowledge sources and enables us to represent their concepts in a wider cognitive context referring to ontological theories. The tasks of cognitive ergonomy, quasi-naturalness of language, versatility, and flexibility seem to be supported through some functions, such as viewpoint, context, and sign, which act as spin-off points to knowledge or information which is not modeled.

Artificial Intelligence↗

PubMed1995

Some new 3-methoxy-5-methyl-1,4-substituted pyrazoles.

A series of 3-methoxypyrazole derivatives was synthesized and tested as antifungal agents. The substituents were chosen on the base of their lipophylicity and for their presence in well-known antifungal drugs. The compounds displayed no significant activity in vitro.

Antifungal Agents↗