[Spontaneous rhythmic contractions of human placental vessels: is it an evidence for a physiological pacemaker in blood vessels?]. / Actividad rítmica espontánea en vasos de placenta humana: un marcapaso fisiológico en los vasos sanguíneos?

BACKGROUND: Placental vessels are not innervated. Therefore the vasomotor activity and vascular tone is not regulated by the nervous system. AIM: To assess the existence of pacemaker mechanisms related to rhythmic motor activity of blood vessels. MATERIAL AND METHODS: Isometric contractions of rings from umbilical and chorionic vessels of term human placentas were monitored. RESULTS: Recordings of the circular layer of chorionic and umbilical vessels revealed rhythmic spontaneous contractions with a frequency of 1.4 +/- 0.05 cycles/min, the duration of each cycle was 42.8 +/- 0.24 s (n = 12). The amplitude of contractions was larger in veins than in arteries, predominating in umbilical vein biopsies, proximal to the fetus. Both the frequency and the amplitude of contractions were relatively constant during the first 30 min. However, after an hour, the frequency declined while the amplitude increased. The absence of the endothelium neither modified the frequency nor the amplitude of the rhythmic activity. Blockage of voltage dependent sodium channels or calcium channels did not alter the frequency of spontaneous contractions, although their magnitude was reduced. Glibenclamide, an ATP-dependent K+ channel blocker or the blockade of gap junctions ablated the frequency and amplitude of spontaneous contractions. CONCLUSIONS: We propose that rhythmic contractions are triggered by pacemaker cells located in the circular layer of the smooth muscle of blood vessels and spread via gap junctions; they likely contribute to the control of blood flow.

[Ulcerative colitis and pregnancy]. / Colitis ulcerosa y embarazo.

BACKGROUND: The evolution of ulcerative colitis in pregnancy is far from clear. While some authors state that the disease aggravates during this period, others do not share this opinion. AIM: To assess the evolution of ulcerative colitis in pregnancy. PATIENTS AND METHODS: A paired case-control design was used in which 15 women, with diagnosed ulcerative colitis at the moment of becoming pregnant, were followed for 12 months and the activity of the disease was compared with that of the 12 months preceding the pregnancy. The activity of the disease in the period preceding the pregnancy was gathered retrospectively from the patient's charts. RESULTS: The mean age of the first ulcerative colitis crisis was 24 years. It was moderate in 49% and severe in 35% of women. During pregnancy 55% of women did not have a crisis, compared with 26.7% during the period preceding pregnancy (relative risk of not having a crisis during pregnancy of 1.7). During both periods, seven women had digestive complications, whereas extra digestive complications were not observed in 60% of patients during pregnancy and 11.8% of patients during the preceding period. Perinatal results were similar to those of the general population. CONCLUSIONS: In our group of patients the evolution of ulcerative colitis was better during pregnancy, reflected by a lower number of crisis.

Neuropeptide Y Y1 receptors are involved in the vasoconstriction caused by human sympathetic nerve stimulation.

Neuropeptide Y, a novel neurotransmitter, interacts with selective membrane receptors to cause vasoconstriction. Frequency- and concentration-dependent isometric contractions were observed in human inferior mesenteric artery and vein mounted rings that were stimulated with either electrical pulses (70 V, 0.5 ms, 2.5-20 Hz) or noradrenaline. The antagonism elicited by 100 nM tetrodotoxin and 1 microM guanethidine confirmed the neuronal and sympathetic origins of the vasomotor response. Incubation with BIBP 3226 ((R)-N2-(di-phenacetyl)-N-(4-hydroxyphenyl)-methyl-D-arginineam ide), a selective neuropeptide Y Y1 receptor antagonist, significantly reduced the vasoconstriction. The incomplete antagonist activity of BIBP 3226 tends to support the hypothesis of sympathetic co-transmission involving neuropeptide Y, adenosine 5'-triphosphate and noradrenaline. These findings were confirmed in parallel studies using rat superior mesenteric artery and vein ring preparations.

[Analysis of 1017 large intestine adenocarcinomas resected in 978 patients]. / Análisis de 1.017 adenocarcinomas del intestino grueso resecados en 978 pacientes.

BACKGROUND: Colorectal carcinoma is the fifth cause of cancer deaths among women and the sixth among men. AIM: To retrospectively analyze the distribution by sex, age, localization and the pathologic features of resected large bowel adenocarcinomas at a surgical service. MATERIALS AND METHODS: All biopsy reports of resected large bowel carcinomas between 1959 and 1995 were analyzed. Twenty six reports were discarded. Available histological slides were re-examined. RESULTS: Twenty five cases (2.5%) had two synchronous tumors and 14 subjects (1.4%) had two different resections due to cancer (metachronic tumors). Sixty percent of tumors were located in the rectum and sigmoid, 74% were well differentiated, 17% poorly differentiated. Mucinous and signet ring cell variants were found in younger subjects and in 5.1% and 2.3% of all patients respectively. Eighty four percent of tumors were beyond the muscularis at the moment of resection and 38% had lymph node metastasis. Comparing the 1959-1979 with the 1980-1995 period, the mean age of patients increased from 60 to 65 years old and rectal cancer frequency decreased from 37.8 to 25.4%. CONCLUSIONS: Colorectal carcinoma is still diagnosed at an advanced stages and the changes of the natural history of the disease observed in the two analyzed periods are similar to those reported in USA and Colombia.

[Perineal endometriosis. Clinical experience with 8 patients]. / Endometriosis perineal. Experiencia clínica en 8 pacientes.

We report our experience with 8 women with perineal endometriosis managed in a period of 20 years. All were multiparae women presenting with cyclical perineal painful masses related to menstrual periods. Symptomatology started 6 months to 16 years after last delivery. Three patients had partial involvement of the anal sphincter. The endometriosis area was locally resected in all women. There were no complications and no problems with anal continence. Two patients had local recurrences. The different lapses between delivery and symptomatic presentation can be related to the amount of endometrial basal cells implants in the episiotomy. The treatment is always surgical. All endometrial implants must be resected and sphincteric structures must be repaired posteriorly.

[Gastrointestinal bleeding of unknown origin. Experience in 31 cases]. / Hemorragia digestiva de origen oculto. Experiencia en 31 casos.

Thirty one patients with GI bleeding of obscure origin, defined as those with normal upper endoscopy and colonoscopy, were studied to know the yield of different diagnostic procedures. Seventeen patients consulted for hematochezia and bleeding less than 10 days of evolution in 71%. Small bowel X ray examination was performed in 14 cases with a diagnostic effectiveness (number of diagnosis/number or examination) of 14%, angiography was performed in 12 cases with an effectiveness 33%, radiolabeled erythrocyte scanning in 12 cases with an effectiveness of 75%, scintigraphy with pertechnetate in 6 cases with an effectiveness of 17% and intraoperatory endoscopy in 2 cases with an effectiveness of 50%. A definitive diagnosis was reached in 8 patients during the first admission and in 6 during the second admission. The principal etiologies were small bowel tumors in 3 cases, cecal ulcers in 2 and ileal diverticula in 2. Ten subjects were subjected to surgical and 2 to endoscopic treatment. Five patients with recurrent bleeding remain without diagnosis. It is concluded that radiolabeled erythrocyte scanning and angiography are effective examinations that should follow upper and lower endoscopies in the diagnosis of a concealed GI bleeding. When a diagnosis is not reached in the first admission, patients should be following with repeated diagnostic procedures.

[Colorectal cancer. Study of survival and surgical results]. / Cancer colorrectal. Estudio de sobrevida y resultados quirurgicos.

The aim of this study was to assess the progress in the surgical treatment of colorectal carcinoma in a 15 years period at the Catholic University Clinical Hospital. The medical records of 397 patients were retrospectively analyzed. Two hundred eighty four patients (164 male) aged 24 to 90 years old, subjected to elective and curative interventions, were selected for the study and separated in two groups: 132 subjects operated between 1975 and 1984 (group A) and 152 operated between 1985 and 1989 (group B). Group B patients were older (66.7 vs 61.3 years old), had a higher proportion of Dukes A tumors (11 vs 18%) and a lower proportion of lesions localized in the rectum (37 vs 49%). Rectal operations had higher morbidity than colonic interventions (35 vs 17.5%). Operative mortality was 0.7% in group A and 0.6% in group B. Ninety one percent of patients had a mean follow up of 38 months. Five years actuarial survival was 52% in group A and 69% in group B and 58, 74 and 46% for tumors Dukes A, B and C respectively.

[Vascular compression syndrome of the duodenum. Report of 2 cases]. / Síndrome de compresión vascular del duodeno. Communicación de 2 casos.

Two young female patients with the syndrome of vascular compression of the duodenum are reported. Both patients presented with a history of vomiting and weight loss. Barium examination of the gastrointestinal tract showed in both cases, marked stomach distention and obstruction of the third portion of the duodenum. In one patient, abdominal CT scan discarded other causes of extrinsic compression. Both patients were operated. The simpler and safer surgical procedure is the section of the Treitz ligament and duodenal liberation, which can be used in the majority of patients.

[Acute severe pancreatitis. Analysis of mortality and morbidity]. / Pancreatitis aguda grave: analisis de la mortalidad y morbilidad.

Sixty-three patients with severe acute pancreatitis have been studied. Pancreatitis was associated with biliary tract disease in 23 patients (36.5%) and with alcoholism in 21 (33.3%). It occurred post-operatively in 9, and was associated with other conditions in 10. We evaluated the Ranson prognostic signs (RPS) with the appearance of complications. 36 patients (57.2%) had 3-4 RPS, 9 (30.2%) had 5-6 RPS and 8 (12.6%) had 7 or more RPS. Diagnostic laparotomy was performed in 11 patients (17.5%). 55 patients were operated one or more times due to failure of medical treatment and/or local and septic complications. The most frequent complications were pancreatic abscess (60.3%), sepsis (58.7%) and pulmonary insufficiency (52.4%). Renal failure occurred in 26 patients and 9 required dialysis. Of the patients with renal failure, 84.6% (22/26) had 4 or more RPS; 78.4% (29/37) of those with sepsis and 71.6% (27/38) of those with pancreatic abscess also had 4 or more RPS. The mean duration of hospitalization of survivors was 58 +/- 30 days. Overall mortality was 28.6%. We conclude that RPS are helpful to predict complications in patients with severe pancreatitis.

[The rupture of a hepatic subcapsular hematoma during pregnancy: a report of 2 cases]. / Ruptura de hematoma subcapsular hepático durante el embarazo: reporte de dos casos.

Two clinical cases of spontaneous rupture of subcapsular hepatic hematomas in two hypertensive pregnant patients are described. They were successfully treated with conservative surgery.

[Diverticular disease of the colon, the indications for and results of elective surgical treatment]. / Enfermedad diverticular del colon, indicaciones y resultados del tratamiento quirúrgico electivo.

Precise criteria were prospectively used to indicate surgery in patients with diverticular disease of the colon: a) anatomical deformity of the sigmoid (ADS), including stenosis and fistulae with presence of contrast media extraluminally; b) recurrent acute diverticulitis (RAD); c) prior diverticulitis with perforation (DP) and d) recurrent GI bleeding (GIB). 42 patients were operated on according to these criteria, from 1978 to 1988, 26 males and 16 females, with a mean age of 61 years (range 31 to 93). ADS was the indication in 22 patients (52%), with fistulae present in 9. RAD was the indication in 16 patients (37%), DP in 9 patients (21%) and GIB in 5%. All patients were submitted to either ample sigmoid resection or left hemicolectomy. All patients were followed, with a mean of 43 months for the series. Only 1 patient died after surgery from pulmonary embolism. Late clinical evaluation revealed absence of preoperative symptoms and signs. We feel that surgical treatment of diverticular disease of the colon is warranted with the criteria described, with good immediate and longterm results.

[The medical treatment of intestinal obstruction due to adhesions and adherences]. / Tratamiento médico de la obstrucción intestinal por bridas y adherencias.

Adhesions are the most common cause of intestinal obstruction. Medical treatment for those patients with no signs of vascular involvement has been successful in many cases. We reviewed the clinical records of 87 patients with intestinal obstruction due to adhesions, having a total of 122 episodes. Satisfactory follow up was obtained in 76% of patients for a mean of 29.6 months. 47% of episodes resolved without need for surgical intervention. Volume entrapment during the first hours was correlated with need for surgical treatment (p < 0.01). Recurrences were not different between medical and surgical patients (p = 0.28). Thus, medical treatment of this type of intestinal obstruction may be attempted in most patients, not only those who are poor surgical risks.

[Value of preoperative colonoscopy in colon-rectal neoplasms]. / Valor de la colonoscopia preoperatoria en el cancer colo-rectal.

The surgical approach to treat colo-rectal carcinoma is usually based on the findings of barium enema. In 102 patients we reviewed the yield of pre-operative colonoscopy. Barium enema revealed the cancer in 76 of 84 patients (91%), whereas colonoscopy did so in 96 of 102 subjects (94%). In addition, 5 associated cancerous lesions were demonstrated by colonoscopy and none by barium enema. Associated benign lesions were seen in 14 patients. In 5 patients the surgical plan based on the barium enema was modified by the findings at colonoscopy. Eight false negatives to barium enema were correctly diagnosed by colonoscopy. We conclude that colonoscopy yields valuable information, beyond that of barium enema, in patients with colo-rectal cancer.

[Gastric cancer: surgical results and survival]. / Cáncer gástrico: resultados quirúrgicos y sobrevida.

From 1975 to 1984, 292 patients with gastric cancer were treated according to a prospective and standardized surgical protocol. This series included 195 men and 97 women, with an average age of 62.5 +/- 11 years (SD). In 20 patients (6.8%) surgery was not performed and 99 were considered unresectable at laparotomy. Gastric resection was performed in 173 (63.3%) (distal subtotal gastrectomy in 94 and total gastrectomy in 79). Operative mortality for subtotal gastrectomy was 3.1% and 6.3% for total gastrectomy. Early gastric cancer was found in 21 patients (none presented lymph node metastases). The cancer invaded the muscular layer in 18 (31% with lymph node metastases) and reached beyond the muscular layer in 134 patients (60.8% with lymph node metastases). The five year actuarial survival was 0% in patients who did not undergo gastric resection, 35.5% for those patients with tumor invading the serosal layer or beyond who were resected, 56.5% for those with invasion up to the muscular layer and 91.8% for patients with early gastric cancer. For those patients who underwent a curative resection, actuarial five year survival was 81%.

[Colorectal cancer: follow-up after curative resection]. / Cáncer colorectal: valor del seguimiento después de las resecciones curativas.

From Jan 1978 to Dec 1984, 128 patients had a curative resection of colorectal carcinoma. A program for early detection and surgical correction of recurrences was initiated in 88 patients with a mean age of 61 years (range 24 to 85). Seventy two patients complied with the program involving clinical examination, chest X-ray, alkaline phosphatase and CEA determinations and endoscopy at 6 month intervals. Mean follow up was 36 months (range 6 to 60). A total of 28 recurrences (32%) were detected: 4 local, 17 distant and 7 local and distant. Recurrences occurred in 46% of grade C, 19% of grade B and 0% of grade A lesions. Sixty eight% of recurrences were detected within 12 months and 93% within 36 months after surgery. Recurrences were detected by clinical examination in 71% of cases. CEA determination was sensitive (81% and specific (92%) for detection of recurrences in the remaining patients. Four patients (14%) were reoperated on with a survival of 3 to 26 months, all dying from disseminated disease. We conclude that this program did not help to improve the 5 year survival rate of colorectal carcinoma submitted to curative resection. CEA determination may be indicated at 2 month intervals during the period of increased recurrence risk.