Molecular ecology of a facultative swine waste lagoon.

AIMS: To investigate the microbial ecology of three facultative swine waste lagoons. METHODS AND RESULTS: Phylogenetic analysis of sequences in a 16S rRNA gene clone library and fluorescence in situ hybridization (FISH) analyses were used to assess bacterial diversity in a swine waste lagoon. FISH analysis and Gram-staining were used to compare the microbial communities of all three swine waste lagoons. Six operational taxonomic units were in high relative abundance and corresponded to the following phylotypes; Thiolamprovum, Verrucomicrobia, Acholeplasma, Turicibacter, Clostridium and Bacteroides. PCR was employed to detect the genes apsA and dsrAB which encode for enzymes specifically associated with dissimilatory sulfate-reduction within sulfate-reducing bacteria (SRB). Amplification of these genes confirmed their presence within the lagoons. CONCLUSIONS: All lagoons were dominated by purple sulfur bacteria, affiliated to Thiolamprovum pedioforme. The molecular identification of fermentative bacteria and SRB indicate the following metabolic processes within such facultative ponds: sulfur-cycling, fermentation, inter-species hydrogen transfer and carbon cycling. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides the first molecular evidence for the existence of a sulfur cycle which is linked to phototrophic sulfide oxidation by purple bacteria and organotrophic sulfate-reduction by SRB.

The relationship between steroidogenic factor 1 and DAX-1 expression and in vitro gonadotropin secretion in human pituitary adenomas.

The orphan nuclear receptors, steroidogenic factor 1 (SF-1) and DAX-1, are involved in gonadotroph differentiation, and SF-1 has been shown to activate the LH-beta and glycoprotein hormone alpha-subunit (alpha GSU) gene promoters. Pituitary adenomas from 34 patients [13 somatotroph tumors, 4 prolactinomas, and 17 clinically nonfunctioning pituitary adenomas (NFPAs)] were enzymatically dispersed and cultured in vitro for 48 h. Tissue culture medium was collected and assayed for LH, FSH, and alpha GSU; messenger RNA was extracted from adherent cells, and expression of SF-1 and DAX-1 messenger RNA was determined by RT-PCR and verified by direct DNA sequencing. The presence of DAX-1 protein in tumor tissue was confirmed by immunocytochemistry. DAX-1 was demonstrated in all NFPAs, 7 of 13 somatotroph tumors and 0 of 4 prolactinomas. SF-1 expression occurred in 8 of 16 NFPAs, 4 of 12 somatotroph tumors, and 1 of 4 prolactinomas. LH secretion in vitro was greater in NFPAs that were SF-1 positive (P < 0.05). Neither FSH secretion nor alpha GSU secretion in vitro were significantly related to the expression of SF-1 or DAX-1. SF-1-positive somatotroph tumors immunostained positively for LH-beta and/or FSH-beta and secreted gonadotropins in vitro. SF-1 expression is associated with the in vitro secretion of LH by NFPAs. A proportion of somatotroph tumors also express SF-1 and DAX-1 and secrete gonadotropin hormones in vitro.

Diagnosis of Huntington disease: a model for the stages of psychological response based on experience of a predictive testing program.

Persons diagnosed as affected with Huntington's disease (HD) may have similar stages of psychological response to the clinical presentation of the illness. Here we describe a model of these stages of response based on our experience during a predictive testing program for HD. During the Warning Stage, asymptomatic persons are aware of their risk status for HD and develop defenses which favor adaptation to their genetic risk. In response to the initial signs and symptoms of HD (the Incipient Stage) unconscious working through of this realization occurs while it is still kept out of conscious awareness. When symptoms become obvious such that recognition of disease onset is inevitable (Breakthrough Stage) the possibility of the diagnosis of HD is assimilated. After the delivery of the diagnosis during the Adjustment Stage, short- and long-term adaptive responses to living with HD occur. Recognition of the stage of psychological response of a patient who presents with HD is important prior to delivering a clinical diagnosis. In a significant minority of cases, the psychological readiness lags behind the clinical symptomatology and premature presentation of a diagnosis may result in significant untoward adverse events. Understanding of the stages of response may provide a framework for evaluating the psychological state of the person with HD and determining their readiness to receiving the diagnosis. This model may have relevance to the psychological responses of patients to the diagnosis of other late onset autosomal dominant disorders.

Isolated small bowel obstruction as the presenting feature of colonic disease.

Small intestinal obstruction without colonic dilation can be the mode of presentation in a variety of colonic diseases, including carcinoma, diverticulitis, and colitis. Plain abdominal roentgenograms may lead the unwary physician into errors of diagnosis and treatment by suggesting primary small bowel disease. Barium enema examination of the colon will keep the wary physician out of such traps. We describe five patients with small bowel obstruction who had a variety of colonic diseases diagnosed by barium contrast studies. If the reason for intestinal obstruction is not apparent and the need for emergency surgery is not compelling, we recommend an immediate contrast study of the colon to aid in evaluating possible colonic pathology.

Acute diverticulitis of the transverse colon with perforation: report of three cases and review of the literature.

Three cases of perforated diverticulitis of the transverse colon are added to 19 case reports in the English literature. This unusual disease entity is usually confused with acute appendicitis prior to operation and with carcinoma of the colon during the procedure. The cause of these diverticula is unclear, and their clinical presentation resembles that of right-sided diverticula. Segmental resection of the transverse colon together with end-to-end anastomosis is the treatment of choice, except in the occasional instance of a large intra-abdominal abscess, when anastomosis may be deferred.

Giant diverticular of the sigmoid colon: a review of differential diagnosis and operative management.

Giant sigmoid diverticula ("giant gas cysts," "giant sigmoid cysts") are an unusual complication of diverticulitis. We have recently seen two patients with such lesions, bringing the total number of reported cases to 48. Most patients are elderly and complain of abdominal pain or the presence of an abdominal mass. Air trapping by a ball-valve mechanism may be responsible for formation of the fibrous cysts. The gas-filled structures can usually be differentiated from other conditions by contrast studies. Excision of the cyst and adjacent colon with anastomosis can usually be accomplished safely under elective circumstances.

Masking of ruptured abdominal aortic aneurysm by incarcerated inguinal hernia.

Inguinal hernia incarceration is one of the many conditions that can mask the presence of a ruptured aortic aneurysm. Hypotension, anemia, and retroperitoneal blood in the inguinal operative field suggest that this aneurysm is present. Delay of appropriate treatment increases the mortality from this highly lethal condition.

Detection of a R173W mutation in the porphobilinogen deaminase gene in the Nova Scotian "foreign Protestant" population with acute intermittent porphyria: a founder effect.

OBJECTIVES: Acute intermittent porphyria (AIP) is caused by mutations in the porphobilinogen deaminase (PBGD) gene that disrupt the function of the enzyme. Many mutations that lead to decreased PBGD activity have been described. An Arg to Trp substitution at codon 173 (CGG-->TGG in exon 10) and designated R173W, which leads to a CRIM-negative phenotype, has been reported in Swedish, Finnish, Scottish, and South African kindreds, and in a Nova Scotian proband with fatal AIP. In this work, we investigated the presence of this mutation in a Nova Scotian patient population presenting with AIP. DESIGN AND METHODS: Single-strand conformation polymorphism analysis and DNA sequencing by TA cloning and Sanger's dideoxy chain termination method, were used to confirm the maternal transmission of this mutation to the proband. The mutation also eliminates an Ncil (also Mspl) endonuclease restriction site, which allows for detection of the mutant allele by polymerase chain reaction amplification and restriction enzyme digestion. RESULTS: The family of the Nova Scotian proband and four other AIP kindreds showed the presence of the same mutation. These five families are descendants of German, Swiss, and French immigrants historically known as the "Foreign Protestants," who were recruited to Nova Scotia in the 1750s. CONCLUSION: In all these families, descent from one couple that settled in Nova Scotia in 1751 has been identified by genealogy research, consistent with a founder effect within this population. This is the first identified mutation in PBGD causing AIP that has been linked to a founder effect in descendants of an immigrant population to North America, and which could be traced to such a distant background, similar to the South African variegate porphyria mutation.

Smooth muscle tumors of the stomach.

A series of fifty-one smooth muscle tumors of the stomach seen at the Massachusetts General Hospital over a twenty year period is reviewed. Virtually all benign tumors were asymptomatic and were discovered in the course of autopsy or an unrelated operation. Malignant tumors frequently caused symptoms. Contrast studies and endoscopy, although they confirmed the presence of the lesions, were of limited value in differentiating between benign and small malignant tumors preoperatively. Eighty-two per cent of the malignant lesions were well circumscribed, and 57 per cent of patients with gastric leiomyosarcomas survived at least five years after resection. Benign tumors may be treated by local resection, but malignant tumors should be resected widely, with involved adjacent organs if technically feasible.

Multiple colorectal tumors. An appraisal of natural history and therapeutic options.

The clinical course of 101 patients with multiple colorectal carcinomas treated during a 15 year period is documented; 2.8 percent of all patients with colorectal cancer had metachronous tumors and 1.7 percent had synchronous lesions. The median interval between metachronous tumors was 9 years. The symptom duration was shorter before discovery of the second metachronous tumors, yet the second tumors were more malignant than the primary ones. Patients with synchronous tumors were older than those with single colon cancers or initial metachronous lesions. Synchronous tumors were more apt to occur on the right side of the colon than single tumors. Adenomatous polyps were present in the resected specimens 37 to 63 percent of the time. The overall uncorrected 5 year survival rate was only 21 percent. Among 20 patients having subtotal colectomy, the operative mortality was 10 percent. Eleven of 18 survivors of subtotal colectomy were free of disease 2 to 13 years later (average 5.5).

Unusual abscesses in perforating colorectal cancer.

Perforating colorectal carcinomas may be complicated by abscess formation. If unchecked, the abscess may subsequently extend to a number of sites thus requiring emergency medical attention. The cases of five such patients treated at Massachusetts General Hospital are reported. Sepsis may spread in a short period of time over a considerable area in anatomic spaces such as the retroperitoneal space. Recognition of the source of abscess may be difficult. At times, the abscess may be accompanied by subcutaneous emphysema. Prompt diagnosis and elimination of the source of sepsis may be lifesaving.

Carcinoma of the stomach after gastric operation.

Seventeen cases of carcinoma of the stomach occurring late after previous gastric operation are presented. In all instances, patients had undergone gastroenterostomy, with or without gastric resection. Most patients had undergone the initial operation for peptic ulcer disease an average of 18 years before presenting with the tumor. Endoscopic biopsy of the gastroenterostomy and gastric cytologic evaluation offered a high degree of sensitivity and specificity in making the diagnosis. These tumors appeared to originate in the gastric mucosa near the stoma. Survival was poor with both curative and palliative therapy. Alkaline bile reflux, achlorhydria and bacterial colonization are discussed as possible causes. Patients who have undergone partial gastric resection are at increased risk for the development of carcinoma of the stomach remnant. We recommend that any patient in whom new upper gastrointestinal symptoms develop more than 10 hears after partial gastrectomy should undergo endoscopy with biopsy of the gastric mucosa adjacent to the anastomosis.

Operative management of radiation injuries of the intestinal tract.

A review of forty cases of radiation-induced gastrointestinal injuries is presented. Based on this experience and reports in the literature, preoperative management and operative technics are discussed. The increased risk of radiation bowel injury is recognized in patients who have had previous operations. Preradiation contrast studies are advised to identify trapped loops of intestine in the pelvis. Small bowel resection is recommended with localized segments of disease. Bypass operations are preferable to avoid any extensive dissections. Bypass operations have anastomotic dehiscence rates similar to those of resections. Proctocolitis is usually managed by diverting colostomy, with resection in a few favorable cases or with treatment failures. Most rectovaginal fistulas are managed by permanent colostomy. Small bowel fistulas are best treated by bypass with partial or total exclusion rather than by primary resection. Vigorous preoperative and postoperative nutritional support and evaluation are vital because of the poor healing qualities of irradiated bowel. Multiple operative procedures should be anticipated because the natural history of radiation bowel injury is slowly progressive.

Detection and treatment of recurrent cancer of the colon and rectum.

A series of 177 patients with recurrent colorectal cancer treated at the Massachusetts General Hospital is examined retrospectively. Two thirds of recurrences were observed by the second postoperative year, and 15% of patients were asymptomatic. Pelvic recurrences were usually attributable to rectal or sigmoid tumors, whereas right-sided carcinomas frequently spread to the liver. The commonest methods of clinical discovery of recurrence included findings of abdominal and pelvic masses, hepatomegaly, and positive chest films. The average survival after discovery of recurrence was only eleven months, but 23 patients having reresections for cure lived an average of thirty-three months. Seven patients (30%) undergoing reresection for cure represented probable cures. Chemotherapy with intravenous 5-FU provided poor palliation, but radiotherapy gave satisfactory relief of symptoms in approximately 50% of patients, particularly those with rectal or low colon lesions. A program of follow-up is offered since there is evidence that even the symptomatic patient may be well palliated or even cured by surgical resection of the recurrence or palliative therapy.

The urgency of diagnosis and surgical treatment of acute suppurative cholangitis.

Twenty patients with suppurative cholangitis were seen at the Massachusetts General Hospital over a nine year period. Fifteen patients had acute obstructive suppurative cholangitis due to complete obstruction of the common duct, many with coma, hypotension, and positive blood cultures. Sixty per cent of patients were older than seventy years, and most had a history of biliary tract disease. Although most had jaundice, abdominal pain, and fever, clinical symptoms were variable. The diagnosis of cholangitis was made in only 30 per cent of patients before autopsy or surgery. Eighteen patients had calculi in the common duct, and two had primary fibrosis of the ampulla. Patients explored less than 24 hours after admission or deterioration died less often than those operated on after some delay. Most patients underwent common duct exploration and four had a concomitant sphincterotomy. In one instance, cholecystostomy only was performed and this patient died because of ongoing sepsis. The overall mortality was 40 per cent; of those subjected to operation, 25 per cent died in the hospital. Recovery was dramatic among most survivors, and calculous disease did not recur, except for two patients with retained stones. Prophylactic cholecystectomy is recommended to prevent the occurrence of this subtle and highly dangerous syndrome.

Villous adenomas of the colorectum.

During a ten-year period 258 patients with villous adenomas were seen at the Massachusetts General Hospital: seventy-four of these patients (29%) had invasive cancer that developed in adenomas. The operative mortality ascribed to removal of benign adenomas was zero, but for cancer arising in villous adenomas it was 3 per cent. Therapy often is difficult because of the size and location of the tumors. Methods of removal have been considered in detail.

Malignant duodenocolic fistulas.

Five cases of malignant duodenocolic fistula seen at the Massachusetts General Hospital in the past thirty years are reviewed. Rarely encountered, these lesions are characterized by diarrhea, weight loss, abdominal pain, anemia, and sometimes feculent vomiting. Barium enemas are more likely to demonstrate the fistula tract than upper gastrointestinal series. Nutritional deficiencies may be profound, and the use of preoperative hyperalimentation is encouraged. Operations that accomplish only bypass of the fistula are of minimal palliative value, and the fistula should be divided or resected if possible. When feasible, wide resection is the procedure of choice, and a fourteen year survival is reported after this operation.

Carcinoid tumors of the colon. A study of 72 patients.

Since carcinoid tumors rarely originate in the colon (excluding those that arise in the appendix and rectum), there are few large clinical series describing these neoplasms. Seventy-two patients with colonic carcinoids treated over a 40 year period have been reviewed. The peak incidence was in the seventh decade and females outnumbered males 2:1. Virtually all patients were symptomatic, usually complaining of abdominal pain. The symptom duration averaged 3.6 months. Thirty-eight percent of patients had masses in the right lower quadrant and 16 percent, hemoccult-positive stools. Three patients had a documented elevation of the urinary 5-HIAA level. Nearly 70 percent of the lesions were situated in the right segment of the colon. Barium enemas usually detected the neoplasms. Most patients had colon resections and five had resection of adjacent organs. Forty-four percent of the lesions had spread to regional sites and 38 percent to distant points. Most lesions were bulky. The operative mortality was 19 percent overall. Chemotherapy and radiotherapy did not appear to provide good palliation. Synchronous or metachronous neoplasms developed in 30 patients, especially in the colon, during the period of follow-up. The crude survival rates were 58, 51, 25 and 10 percent at 1, 2, 5, and 10 years, respectively.

Primary malignant tumors of the small bowel. The Hartford Hospital experience, 1969-1983.

The medical records of 51 patients with primary small bowel cancer were reviewed. Twenty patients had carcinoid tumors, 17 had adenocarcinomas, 8 had leiomyosarcomas, and 6 had lymphomas. Presenting complaints were protean in nature and only 33 percent of patients had a correct diagnosis at the time of operation. Curative resection was attempted in 55 percent, but most patients presented late in their illness and only 27 percent had localized tumors. Survival has been poor: at most recent follow-up, 59 percent were dead, 14 percent were alive with disease, and 27 percent were alive and well. Earlier diagnosis may improve survival. Patients at risk for these tumors are usually more than 50 years of age with vague complaints such as weight loss, pain, abdominal fullness, and fatigue. They should undergo complete evaluation centered around exhaustive radiographic studies and liberal use of endoscopy.

Management of antacid impactions in hemodialysis and renal transplant patients.

Ten cases of intestinal obstruction caused by antacid impactions in renal transplant and hemodialysis patients were added to 16 reports in the literature. In six instances, operative intervention was necessary because of failure of vigorous medical therapy. Three patients who died had perforation of the colon at sites of stercoral ulceration due to firm antacid impactions. Aggressive medical and surgical management of constipation and fecal impaction is recommended. The outlook is grim once colonic perforation has occurred.