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Biomedical subjects

A Bianchi

Publications and source records attributed to A Bianchi.

At least 181 records · Page 10Linked to original sources
PubMed1998

Upper digestive tract dyspepsia and early gastric cancer.

AIM: The study of the frequency and evolution of upper digestive tract dyspepsia in a group of patients operated for early gastric cancer (EGC) and to perform a strategy of diagnosis for the patients with long term upper digestive tract dyspepsia. METHODS: Clinical data of 35 patients operated for EGC were retrospectively evaluated. The frequency, characteristics and evolution time of upper digestive tract dyspepsia, main when it began more than 6 months before surgery, were analyzed. Radiologic and endoscopic exams carried out for diagnosis were also evaluated. Histological diagnosis of surgical specimens were considered, looking for the presence of chronic atrophic gastritis, intestinal metaplasia, and peptic gastric ulcer. RESULTS: Long-term upper digestive tract dyspepsia was present in 27 patients (mean evolution time of 43.4 months). Clinical changes of previous symptoms that suggested gastric carcinoma were not found in 15 patients. Concurrent peptic gastric carcinoma were not found in 15 patients. Concurrent peptic gastric ulcer along with EGC was diagnosed by histology in 11 patients, and chronic atrophic gastritis and intestinal metaplasia were both present in the non-tumoral gastric mucosa in all cases. CONCLUSIONS: 1) Unspecific upper digestive tract dyspepsia is frequently found in patients with EGC. 2) Endoscopy should be the first exam performed in patients with upper digestive tract dyspepsia. 3) The patients with gastric ulcer, chronic atrophic gastritis or intestinal metaplasia must be submitted to sequential endoscopic follow-up.

Dyspepsia↗
PubMed1997

TRF1 is a dimer and bends telomeric DNA.

TRF1 is a mammalian telomeric protein that binds to the duplex array of TTAGGG repeats at chromosome ends. TRF1 has homology to the DNA-binding domain of the Myb family of transcription factors but, unlike most Myb-related proteins, TRF1 carries one rather than multiple Myb-type DNA-binding motifs. Here we show that TRF1 binds DNA as a dimer using a large conserved domain near the N-terminus of the protein for TRF1-TRF1 interactions. Dimerization was observed both in a complex with DNA and in the yeast two-hybrid assay. TRF1 dimers were found to require both Myb repeats for the formation of a stable complex with DNA, indicating a parallel between the DNA-binding mode of TRF1 and other Myb-related proteins. TRF1 was found to have a number of biochemical similarities to Rap1p, a distantly related DNA-binding protein that functions at telomeres in yeast. Rap1p and TRF1 both require two Myb motifs for DNA binding and both factors bind along their cognate telomeric sequences without showing strong cooperative interactions between adjacent proteins. Furthermore, TRF1 was found to bend its telomeric site to an angle of -120 degrees. Since Rap1p similarly distorts telomeric DNA, we propose that DNA bending is important for the function of telomeres in yeast and mammals.

Amino Acid Sequence↗
PubMed1997

The non-refluxing gastrostomy: an evaluation.

A gastrostomy is often essential to deliver adequate and safe nutrition. Various types are now available such that the technique can be tailored to the specific needs of the patient. This paper explores the non-refluxing gastrostomy for long-term intermittent gastrostomy feeding, avoiding the need for a permanent indwelling appliance. A full-thickness vascularized flap based on the right gastroepiploic vessels is raised from the greater curve of the stomach. The proximal half of the tubularized flap is buried in a submucosal tunnel and the free distal end is brought to the skin surface as a catheterizable stoma. Fifteen children with varied mental and physical disabilities formed the cohort of the study. There were 3 stomal stenoses and 3 mild mucosal eversions requiring minor surgical adjustments. One child had a wound dehiscence 10 days postoperatively. Once the stoma had healed, the majority fed by intermittent catheterization and bolus feeds at conventional feed times during the day. Intermittent catheterization was painless and easy and was well accepted by caregivers and patients. Perhaps the most important advantages were the increased patient and caregiver confidence and independence, as well as the reduction in anxiety and hospital attendance.

Catheterization↗
PubMed1997

Autonomic function in narcolepsy: power spectrum analysis of heart rate variability.

Ten narcoleptic patients that had never been treated previously and ten healthy volunteers of comparable age underwent 48-h polygraphic recording to assess the effects of wakefulness and sleep on beat-to-beat heart rate variability by means of power spectrum analysis. The study revealed decreased power in the low frequencies (LF) during sleep (whereby an increase of the power in this band is associated with sympathetic activation) compared with wakefulness, with minimal values during stage 3-4 non-REM sleep and higher levels during REM sleep, both in patients and controls. Significantly reduced power in high frequencies (HF; mainly expression of parasympathetic control) and a significantly increased LF/HF ratio during wakefulness before sleep in narcoleptics compared with controls were found. Our study excludes a primary disturbance of cardiac autonomic nervous system in narcoleptics but suggests an altered circadian autonomic function in these patients.

Adult↗
PubMed1997

One-stage neonatal pull-through to treat Hirschsprung's disease.

INTRODUCTION: Traditionally Hirschsprung's disease has been treated by a three-stage procedure. This approach has been associated with stoma problems, three episodes of hospitalization, and a theoretical disadvantage, because of the delayed passage of feces via the rectum, in controlling defecation. The aim of this study was to assess the results of one-stage neonatal pull-through for the treatment of Hirschsprung's disease. METHODS: This was a 10-year retrospective review of all patients treated with a neonatal pull-through for Hirschsprung's disease. Information was obtained from the patients' records. All descriptive data are expressed as mean +/- standard deviation. RESULTS: Fifty-one patients were treated in the 10-year period studied. The mean gestational age was 39.6 +/- 1.7 weeks, weight was 3.3 +/- 0.54 kg, with 76% being boys. The surgery was performed at 10.3 +/- 5.8 days of age. A Swenson procedure was carried out in 38 patients and a Soave in 13. The extent of the disease was rectosigmoid in 39, and the remaining were sigmoid, descending colon, and total colonic. The mean length of the surgery was 181 +/- 40 minutes. Blood transfusions were required in 13 patients with a mean volume of 55 mL given. The complications observed were: an anastomotic leak in two cases, requiring laparotomy and colostomy (both in patients with Down's syndrome), and wound infection in three cases. There were two delayed deaths both associated with other congenital anomalies. In total, three patients required further surgery; two had colostomies, one requiring a redo pull-through and one had an ileostomy for enterocolitis. The total length of hospital stay was 20.4 +/- 11.2 days. Mean follow-up was 3.73 +/- 2.9 years. In 21 patients the follow-up was greater than 4 years and in this group none were totally incontinent. Four patients complained of soiling at least once a week, and 17 had normal bowel control. CONCLUSION: Hirschsprung's disease can be successfully treated in the neonatal period with a one-stage pull-through. The short- and long-term results are as good as those with the three-stage procedure, with the child usually benefitting by not having a stoma and a shorter hospital stay.

Anal Canal↗
PubMed1997

Total esophagogastric dissociation: an alternative approach.

BACKGROUND/METHODS: The authors report experience with five children, four of whom underwent esophagogastric dissociation with a Roux-en-Y esophagojejunal anastomosis and jejuno-jejunostomy after recurrent failure of fundoplication to control gastroesophageal reflux. A fifth child had a similar temporary gastric dissociation because of life-threatening aspiration caused by reflux into a colonic neoesophagus. Reversal is planned when the child has achieved sufficient physical growth and accepts a substantial oral intake. Feeding into the dissociated stomach was by intermittent catheterization of a nonrefluxing gastrostomy in four children and a Stamm tube gastrostomy in one child. The postoperative course and follow-up were notable for the rapid improvement in the children's general condition and nutritional status and the reduction in the frequency of pneumonitis. Reflux did not recur. RESULTS: Review of the postoperative course led to a restructuring of surgical management with the development of tailored 'patient-specific' plans based on short-term and long-term prognosis. Failure to thrive, difficulty in child handling, gastroesophageal reflux, and neurological and physical impairment are particular considerations. CONCLUSIONS: The author's limited experience leads us to suggest that esophagogastric dissociation with Roux-en-Y esophagojejunostomy and a nonrefluxing feeding gastrostomy is a useful temporary or permanent 'rescue' procedure. Furthermore, it is the author's view that the procedure may have a useful role as the primary form of management when normal oral feeding is unlikely to become established.

Anastomosis, Roux-en-Y↗
PubMed1997

Physiological role of the opioid-cholinergic interaction in growth hormone neuroregulation: effect of sex and food intake.

Studies performed in animals and humans have suggested a functional interaction between opioid and cholinergic systems in the control of growth hormone (GH) secretion. Moreover, the sex-dependent modulation of GH secretion in humans is well established. To investigate the role of sex and food intake in the regulation of the reciprocal influences of opioids and acetylcholine in the modulation of GH secretion, we studied the GH response to pyridostigmine (PYR) alone and during a naloxone (NAL) infusion in a group of normal men and women before a meal (at 1:00 PM) and postprandially. In women, the response of GH to PYR alone before the meal was significantly lower than in the men (area under the curve [AUC], mean +/- SEM, 320.18 +/- 87.16 v 1,031.06 +/- 333.21 micrograms/L/90 min, P < .01). Before the meal, NAL completely abolished the response of GH to PYR in men (AUC, 1,031.06 +/- 333.21 v 16.50 +/- 7.50 micrograms/L/90 min, P < .01), whereas infusion of NAL did not significantly modify the GH response to PYR in women. Consumption of the meal significantly decreased PYR-induced GH release in both women (AUC, 21.75 +/- 12.75 v 320.18 +/- 87.16 micrograms/L/90 min, P < .05) and men (AUC, 45.75 +/- 18.75 v 1,031.06 +/- 333.21 micrograms/L/90 min, P < .01). Conversely, food intake did not change the effects of NAL infusion on the GH response to PYR either in women or in men. We conclude that the sex-dependent opioid modulation of PYR-induced GH secretion is observed before a meal but not in the postprandial state. Food intake may be hypothesized to influence the cholinergic regulation of GH secretion and the sex-dependent opioid modulation of central cholinergic tone.

Adult↗
PubMed1997

A comparison of natural and recombinant cholera toxin B subunit as stimulatory factors in intranasal immunization.

Cholera toxin B (CTB) is often envisaged and used as an immune stimulating agent in protocols for mucosal immunization. However, the nature of the CTB used (natural vs recombinant) is frequently not taken in consideration. This is important since the usage of natural CTB in mucosal immunization regimen and the mucosal response resulting from such an immunization can be effected by the presence of the CTA subunit in commercial CTB preparations. To clarify this, we have compared natural vs recombinant CTB in an intranasal (i.n.) mucosal immunization procedure using ovalbumin (OVA) as antigen. The results show that recombinant CTB induces similar immune responses like natural CTB. Furthermore, our experiments show that covalent coupling of OVA to CTB is not required for the induction of OVA specific mucosal and systemic immune responses upon i.n. immunization.

Adjuvants, Immunologic↗
PubMed1997

Rigid internal fixation of the jaws in an adult patient with facio-scapulo-humeral muscular dystrophy: report of a case.

This study shows the advantages of rigid internal fixation in the surgical management of a facial deformity in a 29-year-old patient with facio-scapulo-humeral dystrophy (FSHD). After presurgical orthodontic treatment, surgery consisted of a Le Fort I maxillary osteotomy, with 5 mm of anterior movement, and fixation with miniplates. After mandibular sagittal split set-back osteotomy, internal fixation was applied on each side using two bicortical screws; no postoperative intermaxillary fixation was utilized. At the 2-year follow-up, the patient was satisfied with the surgical results; lip competence and occlusion were good. The advantages of using internal rigid fixation are: immediate osseous stability which does not require intermaxillary fixation, improved perioperative airway management (no preoperative tracheostomy) and earlier functional recovery.

Adult↗
PubMed1997

Idiotypic vaccination in B-cell malignancies.

Immunoglobulins contain unique portions, collectively termed idiotypes, that can be recognized by the immune system. Idiotypes expressed by tumor cells in B-cell malignancies can be regarded as tumor-specific antigens and targets for vaccine immunotherapy. Haptens and adjuvants, including cytokines, have been used in several animal models to increase idiotype immunogenicity and establish protective anti-idiotype immunity. These results have been extended by the use of DNA technology, and this has led to the development of a new generation of immunogens, namely fusion proteins and naked-DNA vaccines. The central role of antigen-presenting cells as initiators of anti-idiotype immune responses has also been recognized. Guided by the experimental data, idiotypic vaccination has come into medical use in patients with lymphoma and multiple myeloma.

Antigen-Presenting Cells↗
PubMed1997

Influence of chronic Naltrexone treatment on growth hormone and insulin secretion in obese subjects.

OBJECTIVE: Recent studies have demonstrated the restoration of a normal 24 h GH profile induced by a reduction of insulinaemia after weight loss, suggesting a reciprocal relationship between plasma insulin and GH concentrations. We aimed to clarify if an opiate-induced reduction in plasma insulin could affect GH secretion in obesity. DESIGN: We have studied the insulin response to an oral glucose tolerance test (OGTT) and the GH response to GHRH before and after prolonged treatment with Naltrexone (NTX). C-peptide, IGF-I, IGFBP-3 plasma levels and the IGF-I/IGFBP-3 molar ratio were also determined. SUBJECTS: Twelve obese women (aged 25-41 y; Body mass index (BMI): 31-39 kg/m2) and six lean normal women (aged 25-38; BMI: 19.8-23.1 kg/m2). MEASUREMENT: GH was determined by the IRMA method; insulin, C-peptide, IGF-I and IGFBP-3 were assayed by the RIA method. For molar comparison between IGF-I and IGFBP-3 we have considered 30.5 kDa the molar weight of IGFBP-3. Results are expressed as mean +/- s.e.m. RESULTS: We observed a significant decrease in basal concentration of both insulin (230.1 +/- 34.9 vs 133.2 +/- 16.9 pmol/L; P < 0.005) and C-peptide (3.7 +/- 0.3 vs 2.4 +/- 0.1 micrograms/L; P < 0.02). No modifications in the insulin secretory response to the OGTT were observed. A significant increase of the GHRH-induced GH peak response (7.7 +/- 1.4 vs 19.7 +/- 3.1 micrograms/L; P < 0.01) and GH-AUC (533 +/- 151 vs 1415 +/- 339 micrograms/L/120 min; P < 0.01) was found after NTX treatment. A negative correlation was found between basal insulin and GH peak values, both before (r = -0.641, P = 0.027) and after NTX (r = -0.714, P = 0.013). No modifications were found in IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio. Moreover, NTX affected neither the insulin response to OGTT or IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio in a group of six lean controls. Conversely, NTX significantly reduced the GH response to GHRH, when expressed as both peak and AUC values. CONCLUSIONS: The opiate antagonist significantly reduced basal insulin concentrations and augmented the GH response to GHRH in obese subjects. In the absence of modifications in IGF-I and IGFBP-3 plasma levels and their molar ratio, we propose that insulin may exert a negative feedback on GH secretion.

Adult↗
PubMed1997

Distribution of T-cell signalling molecules in human myeloma.

It is controversial whether altered levels of TCR/CD3-associated signalling molecules play a role in the T-cell dysfunction of cancer patients. In multiple myeloma (MM), peripheral blood T (PBT) lymphocytes are functionally impaired by prolonged exposure to tumour cells, and so we investigated the organization of the TCR/CD3-associated signal transduction machinery. The aim of this study was two-fold: first, to investigate the levels of CD3zeta, p56(lck), p59(fyn), ZAP-70, protein kinase C-alpha (PKC-alpha) and phospholipase C-gamma (PLC-gamma) in MM PBT cells; second, to determine whether levels of expression were correlated with clinical or prognostic factors. Forty-four MM patients were studied and 25 age-matched normal donors served as controls. On average, PKC-alpha was the only significantly decreased (P<0.001) signalling molecule, whereas levels of CD3zeta, p56(lck), p59(fyn), PLC-gamma and ZAP-70 were not statistically different. However, there was wide variation between individual patients, and levels for each single protein also varied. A 75% or greater decrease in protein expression was observed, ranging from 8% (p59(fyn)) to 68% (PCK-alpha) of MM patients. When patients were grouped according to the cut-off values of prognostic factors such as the serum levels of C reactive protein (CRP), beta2-microglobulin (beta2M), neopterin (NPT) and the labelling index (LI%) of bone marrow (BM) plasma cells, the only difference observed was the lower PKC-alpha expression in patients with high serum NPT values. None of the T-cell signalling molecule levels was affected by the duration of tumour exposure, calculated on the number of years and/or months that had elapsed since diagnosis, or by disease status. In conclusion, there was a significant decrease of PCK-alpha in MM T cells; however, neither this decrease nor the heterogenous levels of the other T-cell signalling molecules were clearly correlated with prognosis, duration of tumour exposure, and disease status.

Cell Communication↗
PubMed1997

Antibodies to CD44 enhance adhesion of normal CD34+ cells and acute myeloblastic but not lymphoblastic leukaemia cells to bone marrow stroma.

The role of CD44 in the adhesion of haemopoietic cells to bone marrow stromal layers has not been clearly defined in humans, although its importance in the murine system has been well documented. We have demonstrated that the CD44 antibody, NIH44-1, enhances the adhesion of haemopoietic cells to bone marrow stroma. Normal human CD34+ haemopoietic progenitors and blasts from patients with acute myeloblastic, but not lymphoblastic, leukaemia responded to NIH44-1. All CD44 antibodies tested which bound the same epitope as NIH44-1 also augmented haemopoietic cell adhesion to bone marrow adherent layers; however, antibodies which bound to other CD44 epitopes showed mixed responses. Augmented adhesion was independent of cell metabolism, suggesting that antibody binding resulted in direct activation of the CD44 molecule. However, hyaluronic acid was not the ligand for induced adhesion, nor could we show a role for other CD44 ligands including fibronectin, laminin, collagen or chondroitin sulphate proteoglycan. Similarly, none of the 22 CD44 antibodies tested inhibited the stimulatory effect of the NIH44-1. Expression of CD44 was not sufficient to determine NIH44-1 responsiveness since cell lines and leukaemic cells which failed to respond to NIH44-1 expressed high levels of CD44. Neither CD44 isoforms nor glycosylation patterns could be identified as predictive of response. CD44 antibodies enhanced binding of normal and leukaemic haemopoietic progenitors to bone marrow fibroblasts via an unidentified stromal ligand.

Acute Disease↗
PubMed1997

Reduced visual acuity in elderly people: the role of ergonomics and gerontechnology.

Gerontology is the scientific study of the ageing process and special problems of aged people. Ergonomics is an applied science for optimizing performance and productivity and reducing the risks of injury, discomfort and illness. Gerontechnology is concerned with fundamental and applied research on the complex interaction of elderly people with technological products and the built environment. It has the potential to improve the capability of people confronted by the challenges of ageing. We suggest that gerontechnology may have a particular role in relation to the reduction of visual acuity, and can improve the comfort and safety of older people.

Aged↗
PubMed1997

Longitudinal intestinal lengthening and tailoring: results in 20 children.

Longitudinal intestinal lengthening and tailoring (LILT) is increasingly favoured as a treatment for short-bowel syndrome. In a personal series, 20 children underwent LILT between 1962 and 1997. There was negligible morbidity (hemiloop anastomotic stenosis in 2) and no operative mortality. At a mean follow-up of 6.4 years overall survival was 45%, and certain features were clearly related to outcome. Survivors had > 40 cm of residual small bowel (commonly jejunum) and had little hepatic dysfunction despite parenteral nutrition of similar time and nature as non-survivors. Children who did not survive had < 40 cm of residual small bowel and developed early lethal hepatic dysfunction of unclear aetiology. Outcome did not seem to be influenced by the presence of the ileocaecal valve or the length of residual colon. Children born with short-bowel should be offered LILT at an early stage when still in good physical condition, so as to avoid liver-damaging intraluminal stasis and bacterial translocation and to enhance intestinal adaptation and hepatoprotective factors.

Child↗
PubMed1997

Influence of chronic naltrexone treatment on growth hormone secretion in normal subjects.

OBJECTIVE: To verify if a chronic opioid blockade could affect the GH/IGF-I axis. DESIGN: We have investigated the effects of naltrexone (NTX) treatment on GH response to GHRH in normal women. METHODS: GHRH test (50 micrograms i.v.) performed in seven normal female volunteers (age 25-38 years, with a body mass index ranging from 19.8 to 23.1 kg/m2) before and after 4-weeks NTX treatment (50 mg p.o. daily). RESULTS: Basal GH, IGF-I, insulin-like growth factor binding protein-3 (IGFBP-3) plasma levels and the IGF-I/IGFBP-3 molar ratio remained unaffected by NTX. NTX significantly reduced the GH peak values (15.52 +/- 3.59 vs 4.78 +/- 0.49 micrograms/l; P < 0.01), and GH area under curve (918.93 +/- 253.96 vs 401.09 +/- 79.63 micrograms/l; P < 0.01). CONCLUSIONS: This finding suggests that the long-term opioid receptor blockade has an inhibitory role on GHRH-induced GH secretion. A central influence on neurotransmitter control of GH might be hypothesised. The inhibition of stimulated GH release, without interference with the basal level, could indicate an enhanced somatostatin secretion and/or activity. Opioids could be involved only in the regulation of GH dynamics and not in basal secretion. Nevertheless, a direct involvement of opioids at the pituitary level, which could be modified by NTX, cannot be excluded.

Adult↗
PubMed1997

[Role of macrophages in papillomavirus infections].

Papillomaviruses have naturally a strict tropism to epithelial cells in which they replicate during the cell differentiation. There is no histological evidence of any inflammatory reaction. No leucocyte recruitment is observed and thus, the role of macrophages during the early infectious process in the epithelium remains unknown. This silent, subacute or chronic infectious disease is characterized fundamentally by a dual pathogenic process, including an infectious process leading to the production of infective virus particles during the differentiation of infected epithelial cells, on the one hand, and an oncogenic process due to interactions of viral oncogenes with host cell regulatory proteins after integration of the virus to the cellular genome. The role of activated macrophages on the oncogenic process is clearly established. They contribute to regulate negatively the transcription of the non structural E6 E7 viral oncogenes and have cytotoxic effects to transformed cells by a direct intercellular contact without evidence of an effect due to a soluble factor such as tumor-necrotizing factor (TNF). Macrophages have, hence, a prominent role as cellular effectors of protective immunity against lesions due to papillomaviruses and particularly against the oncogenic process complicating these infections.

Cytotoxicity, Immunologic↗