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Biomedical subjects

A Ferrara

Publications and source records attributed to A Ferrara.

At least 37 records · Page 2Linked to original sources
PubMed1997

Complications of laparoscopic colorectal surgery. Analysis and comparison of early vs. latter experience.

PURPOSE: The aim of this study was to test if the techniques learned during our early learning experience have proved to be effective in reducing the complications specifically related to the laparoscopic technique of colorectal surgery. METHODS: From October 1991 until July 1996, 195 laparoscopic operations were performed on the colon and the rectum. These data were divided into "early" and "latter" groups. The conversion reasons and early and late postoperative complications were analyzed and compared. RESULTS: Incidence of conversions required because of iatrogenic injuries showed a decline from 7.3 percent in the early group to 1.4 percent in the latter group. Sixty-six postoperative complications were observed in 59 (30.3 percent) patients. Complications specifically related to the technique of laparoscopic surgery occurred in nine (4.6 percent) patients. These were postoperative bleeding in three patients, port site hernias in five patients, and left ureteric stricture in one patient. Eight (6.5 percent) of these complications occurred in the early group, whereas one (1.4 percent) occurred in the latter group. Analyzing the conversions caused by intraoperative iatrogenic injuries and the specific postoperative complications together reveals that the incidence of 13.8 percent (17/123) in the early group has been reduced significantly to 2.8 percent (2/72) in the latter group. CONCLUSIONS: On the basis of our experience, we have identified techniques, which are discussed in detail, to make laparoscopic colorectal surgery safe. Strict adherence to these techniques has significantly reduced the incidence of complications, specifically those related to the laparoscopic technique.

Adult↗
PubMed1997

Biofeedback in colorectal practice: a multicenter, statewide, three-year experience.

PURPOSE: Biofeedback treatment is often offered to patients in colorectal centers; however, standards of treatment are still lacking. A dedicated team approach is desirable but difficult to coordinate. We present our three-year experience of electromyographic-based biofeedback treatment offered within a multicenter, statewide organization. METHODS: Between October 1992 and October 1995, 188 patients completed a biofeedback treatment program in one of five coordinated centers within a 200-mile radius. A unified common database was established and continuously updated. A colorectal surgeon served as statewide director, and dedicated teams were established at each location. Each local team included the medical director and a certified biofeedback therapist and had access to a dietitian and a nurse data coordinator. Electromyographic-based biofeedback sessions were given weekly, and a home trainer program was established. RESULTS: A total of 116 patients with chronic constipation had a mean of eight (range, 2-14) weekly sessions. A total of 72 patients with fecal incontinence had a mean of seven (range, 2-11) weekly sessions. A total of 84 percent of the constipated and 85 percent of the incontinent patients had significant improvement with biofeedback treatment. Patient compliance and satisfaction were high. Constipated patients increased the mean number of weekly unassisted bowel movements from 0.8 to 6.5. Incontinent patients decreased the mean number of weekly gross incontinence episodes from 11.8 to 2. CONCLUSIONS: Biofeedback treatment can be extremely successful in both incontinent and constipated patients. A large geographic area can be covered with coordinated centers in which each dedicated team uses a unified treatment protocol, and a common database is established.

Adult↗
PubMed1997

Adjusting to changes in the time of reinforcement: peak-interval transitions in rats.

Thirty rats received training on a peak-interval procedure, where a baseline with a 20-s time of reinforcement was interspersed among cyclic transitions to other reinforcement time values (10, 20, 30, or 40 s), each of which was either in force for only a single session or for 3 sessions. Peak times were close to the time of reinforcement on the 20-s baseline and tracked the new reinforcement times both closely (but not exactly) and very rapidly. Peak time during transitions was affected by the criterion value in force on the previous session, exhibiting a proactive interference effect. Analysis of individual peak times during a session showed that transitions from lower to higher reinforcement time values were usually characterized by abrupt jumps in peak time, whereas descending transitions were mostly smooth but rapid.

Animals↗
PubMed1997

Controlled trial of oral 5-aminosalicylic acid for the prevention of early relapse in Crohn's disease.

BACKGROUND: Recent data indicate that 5-aminosalicylic acid (5-ASA) is most effective in preventing relapse of Crohn's disease in patients with a short duration of remission before enrollment. AIM: To evaluate the efficacy of oral 5-ASA treatment, started immediately after achieving steroid-induced remission, in preventing clinical relapses of Crohn's disease. METHODS: Patients with active Crohn's disease, achieving remission on steroids, were randomized to oral 5-ASA 3 g/day or placebo, while steroids were tapered over 6 weeks. The trial was terminated after interim analysis showed a slightly higher relapse rate in the 5-ASA group, and the calculated probability of seeing a statistically significant difference by completing the study was minimal. RESULTS: Final analysis included 117 patients (58 taking 5-ASA and 59 taking placebo; follow-up 9.2 +/- 6.5 months). Cumulative relapse rates at 6 and 12 months were 34% and 58% in 5-ASA patients and 31% and 52% in placebo patients, respectively (rate difference +0.095; 95% CI = -0.085 to +0.274). Subgroups analysis showed that 5-ASA was equally ineffective in patients with ileal, colonic or ileocolonic disease. CONCLUSIONS: Contrary to previous results, in our study early introduction of treatment with oral 5-ASA did not prevent relapse in Crohn's disease patients treated with steroids to induce remission.

Adolescent↗
PubMed1997

Antimicrobial susceptibility tests on anaerobic oral mixed cultures in periodontal diseases.

The ecosystem of the dental plaque in periodontal diseases is very complex: the study of such micro-organisms, which are mostly strict anaerobes, requires the use of specific techniques under conditions of strict anaerobiosis. The aim of the present study was to design a rapid method to evaluate the activity of antimicrobials on mixed bacterial plaque of subjects with periodontal diseases. The study was carried out using a computerised instrument generally used for simultaneous diagnostic tests with aerobic bacteria. Operative and methodological modifications were made to obtain conditions of strict anaerobiosis and the balanced growth of all the microbial forms present in the mixed cultures of the plaque. Penicillins and cephalosporins were active on all the samples, whereas colistin, gentamicin, kanamycin and nalidixic acid showed no activity. Clindamycin, tetracycline, erythromycin and penicillin G were effective only against some samples. The activity of the antimicrobials towards isolated strains was analogous to that towards the corresponding mixed culture.

Adult↗
PubMed1997

High prevalence of myocardial ischemia and vasoconstrictive hormonal release in hypertension during chronic renal failure.

OBJECTIVE: Indexes of myocardial ischemia and vasoconstrictive hormonal release were evaluated in order to investigate the difference between essential hypertension and hypertension during chronic renal failure. BACKGROUND: Arterial hypertension induces several cardiovascular alterations that reflect themselves either on the heart and/or on the coronary blood flow enhancing the cardiovascular risk. Since chronic renal failure can influence the neuroendocrine response, various mechanisms involved in hypertension during chronic renal failure are still unclear. High endothelin 1 (ET-1) levels have been found both in arterial hypertension and during chronic renal failure. Interestingly, either ET-1 or catecholamines seem also to be implied in the pathogenesis of myocardial ischemia. METHODS: 20 hypertensive uremic and 20 essentially hypertensive patients underwent echocardiographic wall motion and wall thickening analysis performed at baseline and immediately after the end of exercise. Simultaneously, myocardial perfusion was evaluated by 99mTc-MIBI-SPECT. In addition, plasma norepinephrine and ET-1 concentrations were measured at baseline and at peak exercise. RESULTS: The segmental radionuclide analysis showed a greater ischemic degree in hypertensive uremic patients. Yet, we were able to identify one or more regions of the left ventricle in which both systolic thickening measurements and wall motion after exercise were impaired. After exercise, wall thickening impairment was correlated with both wall motion abnormalities (r = 0.72, p < 0.01) and MIBI ischemic grade (r = 0.82, p < 0.001). Basal and after-exercise plasmatic norepinephrine and endothelin levels were higher in hypertensive uremic than in essentially hypertensive patients. Moreover, there was a significant correlation between increments in norepinephrine concentration and MIBI perfusion defects, and between the increment in ET-1 concentration and both MIBI perfusion defects, or kinetic alterations assessed by wall motion as well as by wall thickening. CONCLUSIONS: This is the first cross-sectional study in which a higher degree of myocardial ischemia has been observed in hypertensive uremic patients combined with an enhanced plasma release of both norepinephrine and ET-1. This phenomenon may contribute to enhance the cardiovascular risk of these patients.

Aged↗
PubMed1997

Fibrolamellar hepatocellular carcinoma: results of partial liver resection.

AIM: To assess the results of partial hepatic resection in the treatment of fibrolamellar hepatocellular carcinoma. PATIENTS AND RESULTS: We present six cases of Fibrolamellar hepatocellular carcinoma treated by partial hepatic resection. There were five females and one male with a mean age of 20 (2.6) yr. Five patients were stage IVA and 1 IVB based on the Union International Against Cancer Classification. Two patients, due to recurrent disease, needed further pulmonary resection and a hilar lymphadenectomy. All six cases underwent major resection, three with vascular reconstruction. No operative mortality was recorded; half of the patients displayed some degree of morbidity. One patient died six months after the operation and the rest are alive at 78, 41, 24, 12 and 9 months. We believe that even in advanced cases, an aggressive surgical policy even with vascular reconstruction is justified in patients with fibrolamellar hepatocellular carcinoma.

Adolescent↗
PubMed1997

Are we correctly using the inhibitors of gastric acid secretion and cytoprotective drugs? Results of a multicentre study.

AIM: To evaluate indications and frequency of prescriptions of pH-modifying and cytoprotective drugs in hospital departments. DESIGN OF THE STUDY: Multicentre cohort transverse relevation. MATERIALS AND METHODS: On a randomly selected day the clinical charts of 3685 inpatients were reviewed by a gastroenterologist and data were collected concerning the drug used, its dosage and indications for the prescription. RESULTS: 26.8% of hospitalized patients were under treatment on the day of the study. Ranitidine was the most frequently prescribed (73.9%). The purpose of treatment was cure of acute disease or symptoms in 27% of cases and prevention of peptic damage in 73%. Fear of development of stress mucosal lesions (28%) and therapy with other drugs (56%) motivated prophylactic treatment in the majority of cases. The examination of clinical charts failed to demonstrate any need for treatment in 51.4% of the patients. Disparities in the frequency of prescription between different departments and hospitals were found. CONCLUSION: Criteria used for prescription of drugs for peptic diseases in hospitalized patients should be strictly monitored to avoid excessive and unmotivated use also in general practice.

Acute Disease↗
PubMed1996

Brain activation induced by estimation of duration: a PET study.

Duration information about a visual stimulus requires processing as do other visual features such as size or intensity. Using positron emission tomography, iterative H215O infusions, and statistical parametric mapping, we investigated the neural correlates of time processing. Nine normal subjects underwent six serial rCBF. Three tasks were studied: (a) A temporal generalization task (D task) in which the subjects had to judge (by pressing one of two keys) whether the duration of the illumination of a green LED was equal to or different from that of a previously presented standard; (b) An intensity generalization task (I task) in which the judgment concerned the intensity of the LED; and (c) A control task (C task) in which the subjects had to press one of the two keys at random in response to LED illumination. A significant increase in rCBF during the D task, compared to that during the C task, was observed in right prefontal cortex, right inferior parietal lobule, anterior cingulate cortex, vermis, and a region corresponding to the left fusiform gyrus. A significant increase in rCBF during the I task, compared to that during the C task, was observed in right prefontal cortex, right inferior parietal lobule, right extrastriate cortex, anterior cingulate cortex, left inferior parietal lobule, vermis, and two symmetrical regions corresponding to the fusiform gyri. No significant activation was observed in the D task when compared to that in the I task. We propose that these cortical maps are best explained by the recruitment of visual attention and memory structures, which play a major role in prospective time judgements as indicated by behavioral studies. The data also suggest that the temporal dimension of a visual stimulus is processed in the same areas as other visual attributes.

Adult↗
PubMed1996

Endorectal ultrasound of T3 and T4 rectal cancers after preoperative chemoradiation.

PURPOSE: This study was undertaken to assess the accuracy and ability of endorectal ultrasound (ERUS) to predict changes in rectal tumor stage after a preoperative chemoradiation protocol. METHODS: Since December 1990, all rectal malignancies at our institution have been preoperatively staged with ERUS. ERUS has been an essential tool in preoperative staging of rectal cancer patients, possessing an overall accuracy of 84 percent for T stage and 81 percent for lymph node status in our hands (Williamson PR, unpublished data). Beginning in July 1992, all patients staged with T3 or T4 lesions on initial ERUS have been entered into a protocol consisting of preoperative chemoradiation therapy (CRT). This protocol consists of patients receiving 4,500 to 5,040 rads for five to eight weeks and concomitantly receiving sensitizing doses of 5-fluorouracil and/or leucovorin. All patients were scheduled for sphincter-saving or abdomino-perineal resections six to eight weeks following completion of CRT. A repeat ERUS was performed on each patient one week before surgery. RESULTS: The study group consisted of 15 patients who completed CRT, including 12 males and 3 females. Evidence of tumor shrinkage via ERUS measurement was seen in all patients. Average tumor shrinkage as assessed by ERUS was 16 percent by width and 32 percent by depth of invasion. Sonographic level of invasion and nodal status were each downstaged in 38 percent of patients. Pathologic evaluation comparison revealed that the level of invasion was downstaged in 47 percent and nodal status in 88 percent compared with initial ERUS staging. Of those patients downstaged, 4 of 11 (36 percent) revealed no tumor in the pathology specimen. CONCLUSIONS: We conclude from our early experience that although ERUS offers a method for assessing degree of shrinkage and downstaging of T3 and T4 lesions after CRT, presently it does not closely predict the pathologic results. Results are strongly related to the experience of the ultrasonographer. The ability to distinguish tumor from radiation-induced changes to perirectal tissues is under continued investigation, and a new method of interpreting the data obtained by ERUS after CRT will need to be established.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Laparoscopic resections for colorectal carcinoma. A three-year experience.

UNLABELLED: Laparoscopic resection for carcinoma of the colon and rectum is currently under intense scrutiny. PURPOSE: The purpose of this study is to review our three-year experience of laparoscopic surgery for colon and rectal carcinoma. METHODS: From October 1991 to September 1994, 76 laparoscopic procedures were performed for colorectal neoplasia (32 males and 44 females; mean age, 69 years). Fifty-five procedures were done for carcinoma, 16 for large polyps, and five for diversion in patients with unresectable cancer. For resectable tumors, the average size was 4 cm; staging was as follows: Dukes A, 10 patients; Dukes B1, 11; Dukes B2, 18; Dukes C1, 1; Dukes C2, 9; and Dukes D, 8. Fourteen cases (25 percent) that were converted to open procedures were compared with the 41 cases that were completed laparoscopically for differences in tumor size, surgical margins, number of lymph nodes harvested, length of hospital stay, and evidence of recurrence. Procedures completed laparoscopically were then compared with a group of open controls completed during the same time period. RESULTS: During the first six months, the conversion rate was 32 percent but dropped to 8 percent in the last six months. There were a total of 19 complications (25 percent), of which 8 (14 percent) were directly related to the laparoscopic technique. The mean number of lymph nodes harvested in laparoscopic resection for carcinoma was 8.5, and the average closest tumor margin was 4.5 cm. When laparoscopic resections were compared with converted and standard open colectomies, there was no significant difference in tumor margins or numbers of nodes resected. Length of stay was significantly shorter for anterior resections completed laparoscopically than for converted or conventional colectomies. Although this was also the trend for right hemicolectomies, it did not reach statistical significance. Mean follow-up of the group completed laparoscopically was 16.7 months, during which there was one recurrence. There were no trocar site recurrences. CONCLUSIONS: This early experience seems to indicate that laparoscopic surgery for colorectal carcinoma does not per se compromise surgical oncologic principles and encourages us to continue our critical appraisal of this technique.

Colectomy↗
PubMed1996

Sporadic fundic gland polyps: an immunohistochemical study of their antigenic profile.

Fundic Gland Polyps (FGPs) are small sessile (2-5 mm), usually multiple polyps arising in the gastric, acid-secreting mucosa of disputed histogenesis. They have been described in a sporadic form, prevalently in middle aged females, or associated with familial adenomatosis coli-Gardner's syndrome. We performed an immunohistochemical study on 24 sporadic FGPs, using monoclonal antibodies (MAbs) against differentiation markers, class II MHC antigens (HLA-DR), oncofetal and proliferation antigens, aimed to characterize the antigenic profile of the polyps. A preliminary cytogenetic study on five polyps was also done, using an in situ culture method after collagenase treatment. Cytokeratins 8-18 (CAM 5.2 MAb) and 20 (IT-Ks 20.8 MAb), Epithelial Membrane Antigen (EMA) and Chromogranin A were normally expressed by FGPs. FGPs did not express HLA II DR. FGPs did not react with an anti-CEA MAb (F6), but they were frequently positive (22/24, 91.6%) with B72.3 MAb (reacting with the cancer-associated mucin epitope sialyl-Tn). The PC10 MAb (against PCNA or cyclin) showed enhanced expression in the deep glandular-cystic compartment of FGPs; the PCNA index of FGPs was significantly higher than in normal fundic mucosa. The cytogenetic study on the 5 cases analysed, revealed a normal karyotype. We have demonstrated that FGPs express in the paranuclear zone the sialyl-Tn epitope, a side-chain sugar normally masqued in adult gastric mucins, thus revealing an alteration in mucin synthesis; FGPs' higher proliferation index as compared with normal fundic mucosa supports the hypothesis of their hyperproliferative nature.

Antigens, Neoplasm↗
PubMed1996

Stimulus range effects in temporal bisection by humans.

Two experiments with human subjects, using short-duration tones as stimuli to be judged, investigated the effect of the range of the stimulus set on temporal bisection performance. In Experiment 1, six groups of subjects were tested on a temporal bisection task, where each stimulus had to be classified as "short" or "long". For three groups, the difference between the longest (L) and shortest (S) durations in the to-be-bisected stimulus set was kept constant at 400 msec, and the L/S ratio was varied over values of 5:1 and 2:1. For three other groups, the L/S ratio was kept constant at 4:1 but the L-S difference varied from 300 to 600 msec. The bisection point (the stimulus value resulting in 50% "long" responses) was located closer to the arithmetic mean of L and S than the geometric mean for all groups except that for which the L/S ratio was 2:1, in which case geometric mean bisection was found. In Experiment 2, stimuli were spaced between L and S either linearly or logarithmically, and the L/S ratio took values of either 2:1 or 19:1. Geometric mean bisection was found in both cases when the L/S ratio was 2:1, but effects of stimulus spacing were found only when the L/S ratio was 19:1. Overall, the results supported a previous conjecture that the L/S ratio used in a bisection task played a critical role in determining the behaviour obtained. A theoretical model of bisection advanced by Wearden (1991) dealt appropriately with bisection point shifts discussed above but encountered difficulties with stimulus spacing effects.

Adult↗
PubMed1996

Effective peritoneal and fascial closure of abdominal trocar sites utilizing the Endo-Judge.

With the increasing frequency of minimally invasive surgical procedures, we have begun to see descriptions of new and unforseen complications. One such complication is the formation of a ventral hernia through an unclosed or poorly closed fascial defect created by trocar insertion. The necessity to perform fascial closure of trocar insertion sites, particularly those greater than 5 mm, has been established and is routinely practiced by the majority of laparoscopists. Standard suture techniques can be difficult and frustrating, and often involve blind closure of the fascial defect. A number of instruments have been developed to facilitate this fascial closure. We are currently using a self-contained disposable fascial closure device (Endo-JudgeTM--Synergistic Medical Technologies, Inc., Orlando, Florida), which is quick and relatively simple to use. It enables secure fascial closure under direct vision with the pneumoperitoneum intact. Initial results reveal consistent fascial and peritoneal closure and no postoperative hernia formation.

Abdominal Muscles↗
PubMed1996

Dehydroepiandrosterone, dehydroepiandrosterone sulfate, obesity, waist-hip ratio, and noninsulin-dependent diabetes in postmenopausal women: the Rancho Bernardo Study.

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) levels were determined in morning specimens from 659 fasting postmenopausal women who were not using estrogen therapy or antidiabetic medication. All women had concurrent oral glucose tolerance tests and measurements of body mass index (BMI) and waist-hip ratio (WHR). DHEA levels were weakly and inversely associated with BMI but not with WHR or glucose tolerance status. DHEAS levels were not associated with BMI but were positively associated with WHR, diabetes, and impaired glucose tolerance. In analyses adjusted for or stratified by WHR, the DHEAS association with abnormal carbohydrate tolerance was reduced but still independent of fat distribution. Because this was a cross-sectional study, it was not possible to determine whether DHEAS levels were raised by central obesity or vice versa. At a minimum, these data strongly suggest that the positive association of DHEAS with both central obesity and abnormal glucose tolerance does not support the thesis that DHEAS protect against diabetes or obesity in older women as had been suggested by animal studies.

Aged↗
PubMed1996

Thyroxine effect on intestinal Cl-/HCO3- exchange in hypo- and hyperthyroid rats.

Changes in transepithelial water and electrolyte transport as causative or contributing factors of the diarrhoea and constipation found associated with changes in thyroid physiology were studied. Albino Wistar rats were pharmacologically made either hypothyroid or hyperthyroid. After sacrifice, the small intestine was mounted in Ussing chambers in order to measure in vitro ion net fluxes under short-circuit conditions. Hypothyroid animals showed an increase in intestinal transit time, Cl- absorption (mainly due to an increment in its mucosal to serosal component) and residual ion flux (which is believed to represent HCO3- secretion) when compared with euthyroid animals. The hyperthyroid animals showed a decrease in Cl- mucosal to serosal transport. Furthermore, a significant correlation was found between serum L-thyroxine (T4) levels and both net Cl- transport (r = -0.74, P < 0.00001) and residual ion flux (r = -0.55, P < 0.005). These results indicate that the effect of T4 is firstly to inhibit Cl-/HCO3- anion exchange thereby influencing transepithelial flux transport and secondly to affect intestinal motility. Such inhibition was not found when T4 was acutely added to rat ileum, suggesting that the effect on electrolyte transport probably requires protein synthesis. In conclusion, the phenomenon observed in vitro could explain the clinical manifestations of constipation and diarrhoea in hypo- and hyper-thyroidism respectively.

Animals↗