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Biomedical subjects

F Baldi

Publications and source records attributed to F Baldi.

At least 109 records · Page 6Linked to original sources
PubMed1987

Effects of Cinnabar on Pyrite Oxidation by Thiobacillus ferrooxidans and Cinnabar Mobilization by a Mercury-Resistant Strain.

The effect of cinnabar on pyrite oxidation by mercury-sensitive and mercury-resistant strains of Thiobacillus ferrooxidans was investigated by using percolation columns. Mercury-resistant strains oxidized pyrite in pyrite-cinnabar mixtures (1 and 10%, wt/wt), whereas a mercury-sensitive strain did not. Elemental mercury was produced by the mercury-resistant strains growing in the pyrite-cinnabar mixtures in percolation columns and in flasks containing cinnabar only. Manometric experiments showed that cinnabar had little effect on oxygen uptake of mercury-sensitive or mercury-resistant cells growing on ferrous sulfate, pyrite, or pyrite-ferrous sulfate mixtures. In addition, shake flask leaching experiments showed that cinnabar had little effect on pyrite oxidation at 1% (wt/wt) but inhibited growth of mercury-sensitive and mercury-resistant strains at 10%. Mercury-resistant strains were unable to grow on cinnabar as an energy source.

Journal Article↗
PubMed1987

Short-term treatment of reflux oesophagitis with ranitidine 300 mg nocte. Italian multicentre study.

A multicentre study involving 9 Italian institutions was carried out to compare the efficacy and safety of ranitidine 150 mg b.i.d. and ranitidine 300 mg nocte in the treatment of reflux oesophagitis. 117 patients with histologically proven oesophagitis were randomly allocated to two comparable treatment groups. Efficacy and reliability were evaluated by clinical and laboratory tests at the beginning of the study, and at 3 and 6 weeks; endoscopy and biopsies were performed at the beginning and at 6 weeks. Treatment with ranitidine for 6 weeks led to total disappearance of gastro-oesophageal reflux symptoms in 60% of patients, with percentages of partial improvement varying between 85% and 95% of cases. Improvement in the results of endoscopic examination was 85%, of which 55% were cured. Microscopic examination revealed an improvement of 36% and 44%, with a cure rate of 18% and 26% respectively. With regard neither to the regression of symptoms nor to the macroscopic and microscopic inflammation of the oesophageal mucosa did statistical examination show significant differences in the therapeutic efficacy of ranitidine 150 mg b.i.d. or 300 mg nocte for treatment of reflux oesophagitis.

Adult↗
PubMed1985

Leiomyosarcoma of the small bowel.

Two cases of leiomyosarcoma of the small bowel are described. Both patients presented a large mass adherent to the intestinal wall, with a central necrotic area communicating with the intestinal lumen. Microscopically, the lesions were identified as grade III leiomyosarcomas.

Aged↗
PubMed1985

Oesophageal motor events at the occurrence of acid reflux and during endogenous acid exposure in healthy subjects and in patients with oesophagitis.

In order to assess the oesophageal motor events associated with the occurrence of gastro-oesophageal acid reflux and those during endogenous acid exposure, we studied six healthy subjects and nine patients with symptoms and lesions of reflux oesophagitis. In the case of each subject simultaneous pressure and pH measurements of the distal oesophagus were taken both in fasting conditions and after a standardised balanced meal. Reflux episodes occurred in the absence of a lower oesophageal sphincter relaxation (34.3%, 17.7%) or in the presence of a relaxation associated (34.2%, 30.8%) or unassociated (31.5%, 51.5%) with a peristaltic sequence, in the controls and patients respectively. No significant differences were found between the two groups. During endogenous acid perfusion the distal oesophagus showed mainly a peristaltic motor activity, but the mean hourly number of peristaltic sequences was significantly lower in the patients than in the controls (33.5 +/- 27.2 vs 81.5 +/- 3.2, p less than 0.01). Our results show that the mechanisms of reflux are similar in controls and in patients, while the peristaltic frequency is reduced in the latter. This motor failure may be responsible for the increased reflux duration observed in patients with oesophagitis.

Adult↗
PubMed1984

Oesophageal function after oral ranitidine: an acute double blind study in normal subjects.

The effect of oral ranitidine on oesophageal peristalsis, LOS basal pressure and gastro-oesophageal acid reflux, was investigated in 6 healthy men in a double-blind randomized study. Simultaneous manometry and pH measurements were performed twice in each volunteer during a five hour study period which included the administration of a standard meal. Ranitidine did not affect the motor parameters studied (amplitude, duration and velocity of the peristaltic waves and LOS basal tone), whereas it almost abolished acid gastroesophageal reflux. Our results show that ranitidine, like cimetidine, does not alter the motor function of the oesophagus, while it virtually abolishes acid gastro-oesophageal reflux in normal man.

Administration, Oral↗
PubMed1982

Function of the internal anal sphincter and rectal sensitivity in idiopathic constipation.

Anal manometry was performed in 8 control individuals (group A) and in 13 patients with idiopathic constipation (group B), 6 of whom were grouped apart (group C) because of an elective delay of the intestinal transit in the rectum. The basal pressure of the internal anal sphincter, the rectal inflation volume necessary to elicit the rectoanal inhibitory reflex, and the duration of the reflex were not significantly different in the three groups, while the maximal amplitude of the reflex was significantly lower in group C at 10 and 100 cm3 of rectal distension. However, the amplitude of the sphincteric relaxation and the rectal inflation volumes were significantly correlated (p less than 0.001) in the three groups. The rectal sensitivity was lower in the patient groups and particularly in group C (p less than 0.05 vs. controls up to 50 cm3 of rectal distension). The results obtained do not support the 'outlet obstruction' hypothesis as a mechanism of idiopathic constipation and point out that rectal hyposensitivity seems to be the only abnormality in these patients, particularly in those with an elective delay of the transit in the rectum.

Adolescent↗
PubMed1981

Gastric secretion and emptying of liquids in reflex esophagitis.

We have investigated the gastric secretory activity and the emptying half-time of a liquid meal in 17 selected patients with reflex esophagitis compared to 10 controls. The basal acid output and the basal and maximal secretory volume were higher in the patient group (P less than 0.05, P = 0.05, and P less than 0.01, respectively), while the maximal acid output and the basal and maximal acid concentration were not different in the two groups. The gastric emptying half-time of a liquid meal was higher in the patient group (P less than 0.001). Our results show that gastric function may be altered in reflux esophagitis patients and suggest particularly that a delayed emptying of liquids may play a role in the pathogenesis of the disease in some patients.

Adult↗
PubMed1980

Effect of various stimulants and inhibitors of gastric acid secretion on mucosal potential difference in man.

Pentagastrin and histamine in doses effective in stimulating gastric acid secretion (5 microgram/kg/h intravenously and 25 microgram/kg intramuscularly, respectively) produce a significant decrease in the gastric mucosal potential difference (PD) in man. In contrast, atropine and cimetidine (2 mg/30 min intravenously and 4.5 mg/kg/h intravenously respectively) cause a significant increase in gastric PD. The subsequent or simultaneous administration of cimetidine reverses the effect of the stimulating agents on gastric PD and pH. Similarly, the subsequent administration of pentagastrin reverses the effect of atropine. The intragastric instillation of 100 c HCl 0.1 N increases significantly the gastric PD valuesp in this case the patterns of PD and pH changes are dissimilar. This study indicates that substances that modify gastric acid secretion also induce changes in gastric PD; this last effect does not seem to depend on variations of the intragastric pH. Therefore, in the clinical evaluation of the gastric PD in man, its multifactorial origin must alway be considered.

Adult↗
PubMed1979

[Diagnosis of chronic reflux esophagitis. Role of endoscopic and histological examination].

Fibroendoscopic and histobioptic study of the distal oesophageal mucosa has been carried out in a series of patients suffering from gastro-oesophageal regurgitation. The regurgitation condition was verified and its extent established by means of anamnestic, spot-fluorographic and manometric-pHmetric investigations. On the basis of the analysis of relations between the extent of the oesophagitis assessed on the basis of endoscopy and that arising out of microscopic examination of the biopsy, it is concluded that there is no complete correspondence between the two techniques insofar as endoscopy can give false positive or false negative results. On the basis of these results and of those of functional investigations, histology is considered desirable even when the oesophageal mucosa is normal, if there are clinical and/or laboratory signs of gastro-oesophageal regurgitation.

Adult↗
PubMed1979

[2 cases of Apud cell tumors of the rectum and colon].

Two cases of Apud cell tumour of the rectosigmoid are presented. The question of gross diagnosis and the therapeutic efficacy of polypectomy are discussed. Lastly, an account is given of the morphological, functional and embryogenetic features of these tumours.

Apudoma↗
PubMed1979

Methylene blue dye spraying method in patients with ulcerative proctitis: a comparative study with morphological findings and functional capacity of the rectal epithelium.

Methylene Blue dye spraying method is currently used in the endoscopic assessment of the colonic mucosa of patients with chronic ulcerative proctocolitis. We have assessed the validity of this method in the evaluation of the functional capacity of the rectal mucosa in 17 patients with ulcerative proctitis and in 5 normal subjects. The ionic transmucosal fluxes of Na+ and K+ and the potential difference were used as parameters of the mucosal function. Our results indicate that methylene blue dye spraying method can be useful in the functional assessment of the rectal epithelium, especially for differentiating normal subjects and patients with mild ulcerative proctitis.

Adolescent↗
PubMed1978

[The aberrant pancreas in gastro-duodenal disease. A clinical, endoscopic-bioptic study].

30 instances of aberrant pancreas were noted in 13,620 routine gastroduodenoscopies (0.22%), usually in the antrum or duodenum (antrum 83.5%, cap 6.6%, D2 6.6%). Symptoms, where present, took many forms and were aspecific, since they were related to size and site. The difficulties surrounding conventional methods of diagnosis are explained. Radiology reveals local alteration in 80% of cases, though its offers formally useful data in only 10%. Endoscopy and oriented biopsy partly make up for this inadequancy, because an aberrant pancreas may present as an atypical, nonumbelicated form that cannot be endoscopically distinguished from other benign growths. In addition, biopsy of the pancreas may be difficult in a submucosal site. Given the relative inefficacy of even the most recent techniques, perendoscopic polypectomy is proposed as a means of combining optimum diagnosis and radical treatment.

Adolescent↗