Effect of crystal orientation on lapping and polishing processes of natural quartz.

Lapping and polishing processes of natural quartz are investigated in relation to crystallographic orientation and applied normal stress. Weight loss measurements and surface profilometry were carried out in X-, Y-, Z-, and AT-cut samples. The relationship found between material removal rate and stress depends on specimen orientation. Based on indentation fracture mechanics, this behavior is discussed in relation to fracture toughness and scratch hardness anisotropy of quartz crystals. Scanning electron microscopy (SEM) shows that brittle microcracking is the primary mechanism involved with material removal in the lapping process. Plastic deformation mechanisms begin to operate on lapped and polished surfaces above a certain value of stress. Surface profiles and SEM micrographs show that the roughness of lapped surfaces decreases with increasing normal stress, but an opposite behavior is observed in polished surfaces.

[Surgical treatment of intestinal obstruction]. / Tratamento cirúrgico da obstrução intestinal.

The etiology of intestinal obstruction (I.O.) has changed markedly since the beginning of this century. In this series, the authors studied 121 cases of I.O. treated surgically; adhesions were the commonest cause of high intestinal obstruction, accounting for 43.03 percent in a total of 79 patients, with hernia being the obstruction lesion in 16.45 percent. Colo-rectal cancer were the commonest cause of low intestinal obstruction accounted for 73.81 percent, with volvulus of the sigmoid colon in 14.28 percent. Complications occurred in 15.7 percent of patients following operative intervention; wound infection was the most common postoperative complication. The overall operative mortality was 9.09 percent.

[Crepitant abdominal cellulitis: a rare clinical presentation of sigmoid tumor]. / Celulite crepitante abdominal: uma rara forma de apresentaacão do tumor do sigmóide.

Unusual infections associated with colorectal tumors may, in some instances, be the sole clue to presence of malignancy. The infections are either related to invasion of tissues or organs in close proximity to the tumor or secondary to distant seeding by transient bacteremia arising from necrotic tumors. The authors present one case of spontaneous crepitant cellulitis in the lower abdominal wall, associated with sigmoid tumor. The patient had abdominal pain in the left iliaca fossa, fever and skin necrosis of the lower abdominal wall in the last 4 hours. At surgery they performed debridement and excision of necrotic tissue (lower abdominal wall) and partial sigmoidectomy with sigmoid colostomy. The patient died 9 months after initial surgery. A study of tumor mass revealed an adenocarcinoma. The presence of crepitant cellulitis in a lower abdominal wall should result in a search for bowel perforation.

[Is it necessary to perform routine intraoperative cholangiography during cholecystectomy?]. / E necessário realizar colangiografia operatória como rotina nas colecistectomias?

The intraoperative cholangiography was carried out in 361 patients with gallstone disease. In 293 (81.16%) patients cholangiography was normal, in 68 (18.83%) was abnormal. Thirty-six (9.97%) patients had pre-operative asymptomatic common bile duct calculi and 20 (5.54%) patients had confirmed suspect of common bile duct calculi during cholangiography. Twelve (3.32%) patients were false-positive and one (0.27%) was false-negative. It is discussed the value of routine intraoperative cholangiography in patients with gallstone disease.

[A single layer suture in gastric cancer surgery]. / Anastomose em plano único de sutura na cirurgia do câncer gástrico.

A total or nearly total gastrectomy was performed in 30 patients with adenocarcinoma of the stomach. The continuity of the alimentary tract was restored by end-to-side esophagojejunostomy or gastrojejunostomy using a Roux-Y and all the cases had one layer extramucosa suture with 3-0 mononylon. The complications were: one case of left subphrenic abscess; one case of anastomotic leakage (esophagojejunum anastomosis); 2 cases of abdominal wound infection. Surgical mortality was 0%.

[Volvulus of the cecum. A case report]. / Volvo do ceco. Relato de caso.

The authors present one case of intestinal obstruction by volvulus of the cecum. The patient had abdominal pain for 4 days. This pain was colicky in nature and of greatest in density in the left iliac fossa. He was nauseated, had anorexia, and had been vomiting. Abdominal distension was present. Plain-roentgenogram of the abdomen showed an enormously distended gas-filled intestinal loop in the upper abdomen just to the left of midline. At surgery there was volvulus of the cecum located in the upper abdomen to the left of midline. The cecum was viable and was relocated in the right lower quadrant and secured to the antero-lateral abdominal wall (cecopexy). The patient made a good postoperative recovery.

Obstructive jaundice caused by blastomycosis of the lymph nodes around the common bile duct.

A case of obstructive jaundice due to granulomatous blastomycosis is presented. The patient had complained of abdominal pain in the right hypochondrium and jaundice. During hospitalization, the laboratory tests showed evidence of obstructive jaundice and complementary tests a distended gallbladder, dilatation of the intra and extrahepatic bile ducts with enlarged lymph nodes of the hepatic hilus. During the operation a cholestatic liver, distended gallbladder and enlarged lymph nodes around the common bile duct were found. Histopathology of the lymph nodes revealed South American blastomycosis. The medical management consisted of amphotericin B. At present the patient is alive and well.

[Sphincteroplasty: its value in the treatment of distal lithiasis of the choledochus]. / Esfincteroplastia: sua validade no tratamento da litíase do colédoco terminal.

Twenty patients in whom sphincteroplasty was performed are presented. In 12 cases the indication was choledocholithiasis with stone impacted in the distal bile duct; 5 cases with choledocholithiasis and oddian stenosis, and 3 cases with residual choledocholithiasis associated with oddian stenosis. The average length of the incision of the ampullary area was 25 mm. The postoperative control made by tube cholangiography evidenced the presence of a wide open choledochoduodenal opening. Amylase activity was followed in all patients. One case of acute pancreatitis and one case of choledochal fistula were recorded as postoperative complications.

[Critical analysis of the treatment of gastric ulcer by proximal gastric vagotomy]. / Análise crítica do tratamento da úlcera gástrica pela vagotomia gástrica proximal.

In the surgical treatment of gastric ulcer (G,U,), the same techniques have been employed as have been used in duodenal ulcer (D.U.). This correspondence also holds true with superselective vagotomy and proximal gastric vagotomy (P.G.V.). The technique was primarily indicated in the treatment of D.U. and had very exciting preliminary results, above all owing to its reduced morbidity both immediately and late after surgery, and to its almost null mortality. With a view to analyzing the results of the use of P.G.V. in the treatment of gastric ulcer, thirteen patients were operated upon who were bearers of G.U. not associated with D.U. nor prepyloric ulcer. There were no operating accidents or immediate post-operative complications, nor was there any mortality. In the post-operative period following lasting an average of 17.7 months, we observed the clinical manifestation of the ulcer and symptoms accompaning the operation in addition to performing endoscopy on all of the patients. Eight patients were absolutely asymptomatic after surgery; one had slight dysphagia that diminished about 3 months after P.G.V. Three patients had recurrence of the symptoms of ulcer and one complained of intense epigastric fullness, vomting, weight loss, and a crisis of diarrhea. Radiologic and endoscopic examinations showed that this last patient had hypotonia and marked gastric stasis that were corrected surgically by means of antrectomy and the reconstitution of GI tract by the BI technique, with good results. In three patients endoscopy showed postoperative recurrence of the G.U., one of whom is assymptomatic with the clinical treatment; the other two were submitted to antrectomy with BI anastomosis in one and a 2/3 gastrectomy with BI reconstruction in the other. The cure of the lesion in 23% of the cases in the post-operative follow-up lasting an average of 17.7 months permits us henceforward to contra-indicate the P.G.V. used per se for the treatment of G.U.

[Cimetidine in the treatment of postoperative peptic ulcer]. / Cimetidina no tratamento da úlcera péptica pós-operatória.

The results of treatment with cimetidine in 12 patients with postoperative peptic ulcer are presented. Anterior surgical procedures were: Billroth II gastrectomy (8 cases), proximal selective vagotomy (1 case), truncal vagotomy plus pyloroplasty (1 case), gastroenteroanastomosis (1 case) and intrathoracic esophagogastric anastomosis (1 case). Clinical diagnosis was confirmed by radiology and endoscopy. Gastric secretion, both, basal and stimulated by Histalog was considered high (basal from 0,82 to 4,68 mEq/1 stimulated from 6,06 to 54,1 mEq/1). The patients were treated with 1,0 g of cimetidine daily, divided in four dosis. Healing assessed endoscopically, was seen in 75%. Treatment with cimetidine failed in three patients (25%) who were submitted to selective vagotomy and their ulcers healed. The authors conclude that treatment with cimetidine in postoperative peptic ulcer is effective and should be the first choice before surgical reoperation.