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Biomedical subjects

A C Campos

Publications and source records attributed to A C Campos.

At least 19 recordsLinked to original sources
PubMed2001

Intermodal blocking in honeybees.

Previous findings of intramodal but not of intermodal blocking in foraging honeybees prompted a new series of experiments with colours, odours, a proximal visual landmark, and a localized geomagnetic anomaly as stimuli. In Experiments 1-2, the landmark was blocked by both colour and odour. In Experiments 3-6, the anomaly was blocked by both colour and odour, but the anomaly failed to block either colour or odour. In Experiments 7-8, the anomaly failed again to block either colour or odour even though it could be shown to develop substantial associative strength in the course of the training. The several instances of intermodal blocking bring the results for honeybees into closer agreement than before with the results for vertebrates. The failures of blocking seem understandable in terms of the relative salience of the stimuli employed without reference to modal relationships. An attentional interpretation is suggested.

Animals↗
PubMed2001

Surgical treatment of morbid obesity.

The prevalence of obesity is increasing rapidly, and it is a major health problem, especially in Western countries. Bariatric surgery causes significant and permanent weight loss and improves the quality of life. It ameliorates or eliminates most of the obesity-related comorbidities. Isolated gastric restriction procedures are technically easy to perform, the morbidity and mortality are low, but the weight loss is unsatisfactory in patients who ingest high-energy food. Combined gastric restriction with gastric bypass or intestinal malabsorption procedures cause greater weight loss, but more nutritional complications.

Developed Countries↗
PubMed1999

Use of TPN in terminally ill cancer patients.

Total parenteral nutrition (TPN) is often used as an adjunct to cancer therapy. However, it is increasingly being used in terminally ill cancer patients without clearly defined reasons. To determine the validity of the use of TPN in terminally ill cancer patients, 26 patients with limited life expectancy due to end-stage cancer were given TPN by their physicians, and the validity of its use was evaluated using the criteria of 1) quality of life, and 2) ultimate outcome. Patients were divided into two groups according to the use of TPN. Group I = TPN as adjunct of medical therapy, n = 15 (eight male, seven female), mean age 32 y. Group II = TPN for in-hospital supportive care, n = 11 (two male, nine female), mean age 56 y. Nutritional status on admission, quality of life (assessed by extent of daily activities, pain, and ability to sustain oral intake), and ultimate treatment outcome were determined. Mean weight loss in patients in Group I was 8.6 kg, 11 patients out of 15 were malnourished; mean weight loss in patients in Group II was 21 kg, and all of the 11 patients belonging to this group were malnourished. Two patients of Group I improved their quality of life, while 6 declined and 7 died; in Group II, 3 improved their quality of life, 4 declined, and 4 died. We conclude that when TPN was given either as an adjunct to in-hospital aggressive therapy for cancer or for in-hospital supportive care, quality of life did not improve in the majority of patients; nor did it influence ultimate outcome. These objective data, thus, raise the question of the validity of the use of TPN in terminally ill cancer patients. However, barring the cost factor, it is recognized that subjective reasons for giving TPN to terminally ill cancer patients persist and include compassionate, ethical, religious, or emotional reasons.

Adult↗
PubMed1999

A multivariate model to determine prognostic factors in gastrointestinal fistulas.

BACKGROUND: Some studies have identified and selected factors that were associated with prognosis in patients with gastrointestinal fistulas, but a multivariate analysis to determine their relative importance and independent predictive value has not been done. The aim of this study was to determine independent prognostic factors for fistula closure and death in patients with gastrointestinal fistulas using a multivariate model. STUDY DESIGN: Several variables were assessed related to spontaneous closure, surgical closure, and mortality in 188 patients with digestive fistulas (duodenal 22.3%, jejunoileal 28.7%, colonic 23.9%, biliopancreatic 25%). Selection of the variables was done through a forward stepwise logistic regression procedure; the final models were used to estimate the probability of closure, either spontaneous or surgical, and the probability of death. RESULTS: Variables significant for spontaneous closure were: cause of the fistula (p = 0.027), fistula output (p = 0.037), institutional origin of the patient (p = 0.026), and occurrence of complications (p<0.001). Organ of origin of the fistula was only marginally significant (p = 0.068). Successful surgical closure was significantly associated with the presence of complications (p = 0.001) and was marginally associated with age (p = 0.069). Variables significant for death were fistula output (p = 0.009) and the presence of complications (p<0.001). CONCLUSIONS: We conclude that the likelihood of spontaneous fistula closure is higher for fistulas with surgical causes, low output, and with no complications. Mortality is higher in patients with complications and with high-output fistulas.

Adult↗
PubMed1999

Conversions and complications of laparoscopic treatment of gastroesophageal reflux disease.

BACKGROUND: Although several authors have documented the safety and efficacy of laparoscopic fundoplication, it is important to determine the rate of conversions and complications of this procedure. STUDY DESIGN: We retrospectively reviewed the protocol sheets of 503 consecutive patients with gastroesophageal reflux disease who underwent laparoscopic fundoplication over a period of 5 years. A Nissen-Rosetti procedure was performed in 492 patients (97.8%) and a Toupet procedure in 11 (2.2%). Sixty-four patients were also subjected to a concurrent cholecystectomy, and one patient had a concurrent cervical pharyngoesophageal diverticulectomy with cricopharyngeal myotomy. Thirty-one patients had previous upper abdominal operations. RESULTS: The period of hospitalization varied from 12 hours to 16 days, with an average of 1.2 days. The operation was converted to an open procedure in 10 patients (2%). The main cause of conversion was the presence of adhesions. The most frequent intraoperative complication was pneumothorax. All pneumothoraces occurred in the first 100 patients. Five patients had significant operative bleeding; two of them required laparotomy for bleeding control. Gastric ulcer was diagnosed in six patients. One alcoholic patient died of acute pancreatitis. Other major complications were two intraabdominal abscesses, one esophageal perforation, one sepsis from gastric perforation, one hemorrhagic shock, and one gastric obstruction from fundoplication herniation. CONCLUSIONS: Conversions and complications of laparoscopic fundoplication are low and decrease significantly with the surgeon experience, but severe and lethal complications may occur.

Adolescent↗
PubMed1999

Recent advances in the placement of tubes for enteral nutrition.

Enteral nutrition is the preferred route for nutritional support compared with parenteral nutrition if the gastrointestinal tract is functionally preserved. Long-standing nasogastric or nasoenteric feeding tubes are not well tolerated. Alternative routes are gastrostomy and jejunostomy. Percutaneous endoscopic gastrostomy/jejunostomy or those guided by fluoroscopy, sonography or tomography should be the first choices. Laparoscopy or laparotomy gastrostomy/jejunostomy routes should be reserved for specific situations. Insufflation of the stomach with air or saline solution facilitates the placement of nasoenteric feeding tubes or percutaneous sonographic-guided gastrostomy. The gastrostomy button is a safe and aesthetic alternative, at least in children. Comparison between percutaneous endoscopic gastrostomy and surgical gastrostomy performed either via laparotomy or laparoscopy favours the first in terms of costs and risks. Whenever associated intra-abdominal procedures or anatomic difficulties arise, a laparoscopic or an open access becomes necessary. Complications with feeding tubes are not uncommon and should be promptly recognized and treated.

Enteral Nutrition↗
PubMed1996

Nutritional management of patients with gastrointestinal fistulas.

Nutritional support plays a key and integral role in the management of patients with gastrointestinal fistulas. It needs to be instituted early to minimize erosion of body cell mass, to prevent further physiologic deterioration of the patient, and to initiate repletion in an otherwise malnourished patient. Furthermore, it allows for rest of the gastrointestinal tract and facilitates healing of the fistula.

Anthropometry↗
PubMed1996

Factors influencing outcome in patients with gastrointestinal fistula.

The analysis of the prognostic factors in patients with gastrointestinal fistula requires an assessment of the quantitative and qualitative characteristics of the study population. General patient characteristics such as age, presence and degree of malnutrition, levels of plasma proteins, diagnosis of cancer or inflammatory bowel disease, or systemic sepsis must be considered, as well as local fistula characteristics. Besides the local anatomic characteristics of the fistulous tract, other factors such as fistula output, organ of origin, cause, and duration of the fistula must be considered in the assessment of a fistula patient. It is recognized, however, that it is very difficult to conclude that the presence of a single prognostic factor increases the risk in patients as complex and heterogeneous as those with digestive fistulas. It remains to be shown whether the combination of several predictive factors may enhance the chances of accurately predicting fistula closure and mortality in digestive fistulas.

Fistula↗
PubMed1996

Extrapyramidal disorder secondary to cytomegalovirus infection and toxoplasmosis after liver transplantation.

A boy underwent liver transplantation for postnecrotic cirrhosis secondary to Wilson's disease. The patient had no neurological clinical manifestations prior to the transplantation. The patient developed dysarthria, dysphagia, spasticity, rigidity, and intention and resting tremor of all extremities. Cranial computerized tomography revealed hypodensity of the thalamus, basal ganglia and external capsule. Anti-cytomegalovirus IgM became positive. At autopsy, there were severe pathological changes at the thalamus and basal ganglia.

Adolescent↗
PubMed1994

[Acute pancreatitis caused by varicella-zoster virus after liver transplantation].

Twenty-six days after liver transplantation for primary biliary cirrhosis, a 52 year-old patient was rehospitalized for viral infection. The clinical features were fatigue, anorexia and vomiting. On physical examination, vesicular skin lesions involving the left 8 th intercostal space were suggestive of herpes-zoster infection. The following day the patient was extremely tired and dyspnoeic. The abdomen was distended with moderate abdominal epigastric pain. The clinical picture worsened rapidly and the patient died a few hours later. Autopsy revealed acute haemorrhagic necrosis of the pancreas due to herpes-zoster virus.

Acute Disease↗
PubMed1992

The comparative effects of abrupt vs. stepwise discontinuation of TPN in rats.

The comparative effects of discontinuing total parenteral nutrition (TPN: caloric ratio of glucose:fat:amino acid = 50:30:20) abruptly or in a stepwise manner on spontaneous food intake were investigated in two studies. Study 1: In 16 rats, TPN was given for 4 days, then stopped abruptly in eight rats. In the other eight rats, TPN was tapered; they received TPN at 75%, 50%, and 25% of their mean daily energy requirements per day for 3 consecutive days, and then switched to normal saline. Total parenteral nutrition induced a significant 60% reduction in spontaneous food intake (SFI) in both groups during the first TPN day. After 4 days of TPN, an 80% decrease in SFI had occurred in both groups. Resumption of SFI was significantly sooner in the abruptly-stopping group than in the stepwise-stopping group. But, in the latter group, there was a significantly greater cumulative caloric intake during the entire study. Study 2: In 32 rats, TPN providing either 100%, 50%, or 25% of their mean daily caloric requirements was given to three groups each of eight rats, for 3 days, then abruptly changed to normal saline; control rats received normal saline throughout. The TPN-induced decrease in SFI was proportional to the caloric density of the solution infused. Three days of 100%, 50%, or 25% TPN infusion led to an approximate 85%, 60%, or 35% decrease in SFI, respectively. Spontaneous food intake recovery was independent of the caloric density of TPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Dynamics of oral intake resumption after general anesthesia and operation in rats.

The influence of general anesthesia and operation on dynamics of postoperative food intake resumption was investigated in eight rats. A laparotomy was performed on each rat under anesthesia induced by intraperitoneally injected chloral hydrate. Spontaneous food intake and feeding indexes were continuously measured using an Automated Computerized Rat Eater Meter (ACREM) before and after operation. Although spontaneous food intake and all feeding indexes were depressed immediately following anesthesia and operation, each feeding index was depressed to a greater degree during the dark vs. the light cycle. Initially, rats fully capable of eating ate fewer, smaller, and shorter meals. The return to normal of each feeding index differed temporally. Thus, although meal number normalized by the third postoperative day, meal size by the sixth postoperative day, and meal duration by the fourth postoperative day, normalization of meal number during the light cycle occurred sooner than during the dark cycle, while the converse occurred with meal size and meal duration.

Anesthesia, General↗
PubMed1992

High frequency-low morbidity mechanical complications of tube feeding: a prospective study.

Because of preferential use of the enteral route for nutritional support, a prospective study of mechanical complications was done in 109 consecutive patients. One hundred seventy-two nasogastric tubes were placed in 60 patients, 42 esophagostomies in 28 patients, 32 gastrostomies in 22 patients and 9 jejunostomies in 8 patients. Data show that the use of enteral feeding tubes is not without complications. The complications fell into two major categories. There were 15 low frequency mechanical complications, of which four (2 carotid artery blowouts, 1 gastrointestinal perforation, and 1 aspiration) were of high morbidity and 11 of low morbidity. There were 132 high frequency-low morbidity complications with the use of 255 tubes. These consisted mainly of unplanned and untimely removal of feeding tubes with interruption of feedings and necessitating tube replacement. Data indicate that the main problems related to the use of enteral nutrition are not the dramatic complications which create notoriety but those related to the ordinary mechanical complications occurring daily and which command little attention because of their low mortality. These can assume importance because of their high frequency and as such are characterized as high frequency-low morbidity complications.

Journal Article↗
PubMed1992

A critical appraisal of the usefulness of perioperative nutritional support.

Preoperative malnutrition is often associated with poor postoperative outcome, yet there is no consensus about whether perioperative nutritional support reduces postoperative complications to the level occurring in well-nourished patients undergoing similar procedures. This is partly because reports evaluating effect of perioperative nutritional support on postoperative outcome vary widely in number of patients studied, primary diagnosis, and duration and quality of perioperative nutritional support. These concerns warrant caution in interpreting reported results, even of randomized studies. However, analysis of published reports suggests that when total parenteral nutrition (TPN) is given to malnourished patients in adequate amounts for greater than or equal to 7-15 d preoperatively, significant improvements in both nutritional status and postoperative clinical outcome are likely to occur. Preoperative total enteral nutrition (TEN) is as effective as TPN in improving postoperative clinical outcome. Postoperative TPN, TEN, and ad libitum oral nutrition are equally effective in reducing postoperative complications. Potential candidates for surgery for whom prompt initiation of preoperative TPN or TEN may reduce operative morbidity and mortality irrespective of nutritional status can be identified on admission.

Enteral Nutrition↗
PubMed1992

Influence of parenteral feeding on spontaneous caloric intake and food selection in rats.

We compared spontaneous caloric intake (SCI) of rats exclusively receiving chow to SCI of rats given the choice of chow or Parmesan cheese, and then examined the influence of parenteral feeding on SCI and food selection. Six rats in a Chow Diet Group were offered Purina chow for 21 days, while five rats in a Choice Diet Group were offered Parmesan cheese or the same chow. Daily SCI (kcal/day) and body weight gain (BWG; g/day) were determined. Rats in the Choice Diet Group ate twice as much cheese as chow for the first 3 days of the experiment. Thereafter, SCI and BWG became comparable in both groups, with no significant differences for the rest of the study. In another group of nine rats, a central venous catheter was inserted. After 7 days, rats were offered chow and water ad libitum during the infusion of normal saline at 3 ml/hour for 3 days (Saline). Then, normal saline was replaced by a total parenteral nutrition (TPN) mixture of glucose, fat, and amino acid providing 85 kcal/day, and rats were randomized to eat either Chow Diet or Choice Diet. In both groups, SCI during TPN was significantly reduced as compared to the SCI on Saline. However, rats in the Choice Diet Group ate three times more chow than cheese during TPN. We conclude that a) food preference can increase SCI for short periods of time; b) TPN reduces SCI; c) TPN modifies food preference; and d) food preference does not increase SCI during TPN.

Animals↗
PubMed1991

Effects of continuous graded total parenteral nutrition on feeding indexes and metabolic concomitants in rats.

The influence of graded amounts of total parenteral nutrition (TPN) on food intake and feeding indexes was investigated in 90 rats housed in Automated Computerized Rat Eater Meter metabolic cages with free access to water and chow. When food intake was stable after catheter placement, 10 control rats continued with the 3 ml/h normal saline used for catheter patency, whereas study rats were given graded TPN continuously for 3 days, amounting to the equivalent of 26% (TPN-26), 53% (TPN-53), 81% (TPN-81), or 114% (TPN-114) of their daily caloric needs. TPN consisted of glucose, fat, and amino acids in the caloric ratio of 50:30:20. In study rats, the graded TPN depressed food intake, meal number, meal size, and eventually food consumption rate, meal sniffs, and intermeal sniffs in a dose- and time-dependent manner. During graded TPN, rats decreased total food intake by eating fewer, smaller, shorter meals at a decreasing consumption rate; sniffing activities were correspondingly curtailed. Stopping TPN led to normalization of feeding indexes. Blood glucose did not change while plasma insulin rose with graded TPN. A decrease in hepatic glycogen and an increase in hepatic triglycerides occurred. Plasma valine, phenylalanine, and methionine rose in a TPN dose-dependent manner. TPN-26 and TPN-53 significantly decreased whole brain amino acids; with TPN-114 no change occurred. Brain influx of tryptophan remained unchanged, but a progressive decrease in brain influx of tyrosine occurred. Whole brain dopamine and serotonin were depressed with TPN-26 and TPN-81 but were normal with TPN-114.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗