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Biomedical subjects

L Fabbri

Publications and source records attributed to L Fabbri.

At least 55 records · Page 3Linked to original sources
PubMed1989

Myosin heavy-chain isoforms in human smooth muscle.

The myosin heavy-chain composition of human smooth muscle has been investigated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, enzyme immunoassay, and enzyme-immunoblotting procedures. A polyclonal and a monoclonal antibody specific for smooth muscle myosin heavy chains were used in this study. The two antibodies were unreactive with sarcomeric myosin heavy chains and with platelet myosin heavy chain on enzyme immunoassay and immunoblots, and stained smooth muscle cells but not non-muscle cells in cryosections and cultures processed for indirect immunofluorescence. Two myosin heavy-chain isoforms, designated MHC-1 and MHC-2 (205 kDa and 200 kDa, respectively) were reactive with both antibodies on immunoblots of pyrophosphate extracts from different smooth muscles (arteries, veins, intestinal wall, myometrium) electrophoresed in 4% polyacrylamide gels. In the pulmonary artery, a third myosin heavy-chain isoform (MHC-3, 190 kDa) electrophoretically and antigenically distinguishable from human platelet myosin heavy chain, was specifically recognized by the monoclonal antibody. Analysis of muscle samples, directly solubilized in a sodium dodecyl sulfate solution, and degradation experiments performed on pyrophosphate extracts ruled out the possibility that MHC-3 is a proteolytic artefact. Polypeptides of identical electrophoretic mobility were also present in the other smooth muscle preparations, but were unreactive with this antibody. The presence of three myosin heavy-chain isoforms in the pulmonary artery may be related to the unique physiological properties displayed by the smooth muscle of this artery.

Animals↗
PubMed1988

Persistent asthma due to isocyanates. A follow-up study of subjects with occupational asthma due to toluene diisocyanate (TDI).

Thirty-five subjects with occupational asthma due to toluene diisocyanate (TDI) exposure were examined. All the subjects were studied with inhalation challenges with TDI and with methacholine. TDI asthma was documented by a positive inhalation challenge to low levels of TDI. Airway responsiveness to methacholine was in the range of asthmatic patients at the time of diagnosis. After an average follow-up interval of 10 months, all the subjects were re-examined. Of the 35 subjects examined, 30 subjects (85.7%) left the workplace, and 5 remained in the same job. Twenty-seven subjects (77.1%) continued to have asthmatic attacks requiring medication for relief of symptoms. At follow-up examination, TDI asthma was documented by a positive inhalation challenge to TDI in 27 subjects. Of these 27 TDI reactors, 22 subjects were removed from occupational exposure to TDI. The TDI reactors had persistent respiratory symptoms and airway hyperresponsiveness to methacholine. At follow-up visit, 8 subjects (22.9%) lost sensitization to TDI; 5 subjects (62.5%) in this group had also normal airway responsiveness to methacholine after removal from exposure. Only 1 subject among the TDI nonreactors complained of mild respiratory symptoms. At diagnosis, there were no significant differences between subjects who recovered and those who did not with regard to age, smoking habits, atopy, duration of exposure to isocyanates, duration of symptoms, baseline FEV1 (% pred), and baseline airway responsiveness to methacholine.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗
PubMed1986

Prostaglandin D2 (PGD2) potentiates cholinergic responsiveness in guinea-pig trachea.

PGD2 dose dependently potentiated the parasympathetic-induced contraction in guinea-pig trachea in vitro. This phenomenon was much more evident in ovalbumin-sensitized guinea-pig trachea. Indomethacin pretreatment enhanced the capacity of PGD2 to potentiate cholinergic-induced contraction in normal but not in ovalbumin-sensitized guinea-pig. PGD2 shifted to the left the curve of the exogenous acetylcholine-induced contraction in guinea-pig trachea, indicating a postsynaptic site of action of PGD2. These data suggest a role of PGD2 in the genesis of hyperreactivity of tracheal smooth muscles, particularly in a model of pulmonary anaphylaxis.

Acetylcholine↗
PubMed1986

The evolution of anti-ulcer therapy with cimetidine. Is a single large nocturnal dose of cimetidine the right therapy for duodenal ulcer?

Peptic ulcer results from the prevalence of agents causing endoluminal lesions over the defence mechanisms of the mucosa of the upper GI tract. Particularly, in the case of duodenal ulcer, the pathogenetic relevance of non-buffered acid secretion of the early nighttime period has been emphasized. This is indeed confirmed by the fact that a single night dose of 800 mg cimetidine has apparently been proved able--in numerous controlled clinical trials--to provide results that are similar to those obtained with the classic dose of 1 g daily or 400 mg twice daily. Our centre carried out a crossover double-blind controlled trial aimed at evaluating titrable acidity and pH during the 24-h period in seven patients with active duodenal ulcer. The single nighttime dose of cimetidine resulted in a significant and long-lasting inhibition of acid secretion during the entire night. During the day, secretory values returned to levels similar to those obtained with placebo, hence allowing normal digestive functions.

Administration, Oral↗
PubMed1986

Comparison between two different posologies of ranitidine on 24-hour gastric acidity in duodenal ulcer patients.

Eight outpatients with active duodenal ulcer, endoscopically proven, entered a controlled double-dummy cross-over study aimed at comparing the effects of ranitidine 150 mg b.i.d. and 300 mg nocte on 24-h intragastric titratable acidity and pH. Both treatments markedly inhibited (p less than 0.01) gastric acid secretion when the mean 24-h results were compared. When the effects of two posologies on nocturnal and diurnal periods were considered separately, 300 mg appeared to control nocturnal acid secretion more actively, while during the day 150 mg b.i.d. seemed to be the more active. Since nocturnal hypersecretion can be considered an important determinant of duodenal ulcer, a large bedtime dose of ranitidine seems to represent a valid therapeutic approach to this disease.

Adult↗
PubMed1984

Computer-assisted morphometry and microdensitometry of transmitter- identified neurons with special reference to the mesostriatal dopamine pathway. Methodological aspects.

New morphometrical and microdensitometrical approaches for evaluation of transmitter-identified neurons in the central nervous system have been developed. These rely at the presynaptic level on the use of immunocytochemistry and at the postsynaptic level on the use of receptor autoradiography. The immunocytochemical analysis involves the indirect immunofluorescence method and the indirect immunoperoxidase method utilizing cryostat and vibratome sections, respectively. In the postsynaptic analysis cryostat sections and tritium-sensitive film were employed. A block diagram representation of the system of the image analyzer used and its connection with its host computer is given. Furthermore, flow charts of the original software developed by our group in presented. The morphometrical analysis has been performed on coronal sections of rat brain resulting in determinations of cell body and cell group parameters. Based on this information, objective criteria have been introduced to assess the existence of a cell group of transmitter-identified neurons in a three-dimensional frame and to give a morphometrical description of this group in the space. Moreover, new quantitative approaches to describe the dendritic and terminal fields have been introduced and for the first time in this type of morphometrical analysis, the Lorenz curves and the Gini index have been utilized in the description of the pattern of dendritic and terminal networks. By means of these morphometrical approaches it became possible to analyze topological and biochemical heterogeneities within cell groups defined in the rostrocaudal frame. In particular, it has been possible to develop a quantitative method for the evaluation of coexistence in nerve cell bodies. This method has been called the overlap method and allows an analysis cell by cell of the possible coexistence of two or more antigens.

Animals↗
PubMed1984

Renal osteodystrophy in CAPD patients.

To assess the influence of continuous ambulatory peritoneal dialysis (CAPD) on the evolution of renal osteodystrophy, we studied 36 adult patients with end-stage renal failure before starting dialysis and after 7-30 months. 17 patients (12 males and 5 females) were treated by CAPD as first treatment and 19 (14 males and 5 females) received maintenance hemodialysis. The two groups were age- and sex-matched and no patient received vitamin D. All patients had adequate clinical and metabolic follow-up with a radiological survey and quantitative bone histology at the start of dialysis and at the end of the study. Serum phosphate concentrations were much easier to control in CAPD than in hemodialysis patients. There was no difference in the evolutive pattern of vascular and periarticular calcifications in the two groups. The 25-hydroxyvitamin D3 levels were frequently lower in CAPD than in hemodialysis patients. In some CAPD patients, there was a significant loss of trabecular bone volume at the end of the study. The radiological and histological appearances of secondary hyperparathyroidism improved or seemed to worsen to a lesser degree in CAPD compared to hemodialysis patients.

Adult↗
PubMed1982

Therapeutic effects of 25-hydroxycholecalciferol and sodium etidronate on renal osteodystrophy.

The effects of long-term treatment with 25-hydroxycholecalciferol (25OHD3) and disodium ethane-1-hydroxydiphosphonate, or 25OHD3 alone on biochemical parameters, and radiographic and quantitative histomorphometry of bone tissue were evaluated in 17 dialysis patients. They all displayed evidence of bone disease consisting of osteitis fibrosa and defective mineralization of varying degree and predominance. 100 micrograms/day of 25OHD3 significantly improved the state of bone mineralization in many patients with a pronounced fall in the osteoid volume and surface and produced a small reduction in the active resorption surface. Serum parathyroid hormone (iPTH) and alkaline phosphatase levels decreased in some patients. The combination of 25OHD3 with EHDP caused the healing of bone mineralization as did 25OHD3 alone and produced a significant fall in serum alkaline phosphatase and iPTH. The mean magnitude of the reduction in iPTH was higher in patients treated with 25OHD3 and EHDP than with 25OHD3 alone. Treatment with 25OHD3 and EHDP seems more effective for the improvement of osteitis fibrosa than is 25OHD3 alone.

Adult↗
PubMed1981

[Septic osteo-arthritis in hemodialyzed patients: an incident not to underestimate (author's transl)].

Three cases of septic osteo-arthritis were seen occuring in patients on dialysis treatment. The sites of involvement included lumbar spine, knee joint, ribs and wrist. The culture of the same microorganisms simultaneously from the arterovenous prothesis, blood and synovial fluid supports the hypothesis that the osteo-arthritis was the result of hematogenous spread of bacteria from the infected focus. Early diagnosis and treatment may prevent severe bone and joint damage.

Adult↗
PubMed1979

[Incidence and evolution of soft tissues calcifications in patients in periodic hemodialysis (author's transl)].

In a series of 92 patients' in hemodialysis the evolution of periarticular and vascular calcifications has been studied. A correlation exists between the incidence of arterial calcifications and the patients' age, while no direct correlation has been proved to exist with the duration of dialysis. In fact their annual average increase (8.4%) is similar to that of periarticular calcifications (12.2%).

Adolescent↗
PubMed1978

Treatment of ectopic calcification in uremia.

Nine uremic patients on maintenance hemodialysis who showed wide arterial and/or stable periarticular calcifications in spite of a well controlled hyperphosphatemia were treated with the diphosphonate disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) in doses of 7.5 to 10 mg/kg of body wt/per day for 5 to 9 months. No clinical or biochemical side-effects were noted. A significant reduction of the extent of periarticular calcifications was observed in five patients: two of them had a complete regression of soft-tissue calcifications, and one patient showed a reduction of arterial calcification. EHDP (7.5 to 10 mg/kg of body wt/per day) induced a significant increase of the osteoid volume and osteoid surface without significant modification of the calcification front. No evident effect on bone resorption and on the mineral content of the radius has been observed.

Adult↗
PubMed1977

[Chronic broncopneumopathy and pneumoconiosis in workers employed in phosphoric acid production (author's transl)].

Thirty-five subjects employed in a phosphoric acid producing plant were studied by the authors. The investigation included: history, according to the C.E.C.A. questionnaire for chronic bronchitis and emphysema; physical examination, chest X-ray spirometry and lung diffusing capacity for carbon monoxide by the steady state method (DLCOSS). High prevalence of chronic bronchitis (45.7%), obstructive spirometric impairment (37.1%), and decreased values of DlcoSS (31.4%) were detected. Two subjects were found to be affected with p 1/0 and 7 with p 0/1 pneumoconiosis. Such findings were significantly related to the lenght of working activity as well as to dust and gaseous fluoride (hydrofluoric acid, hexafluorosilicic acid and silicon tetrafluoride) exposure.

Adult↗