Genomic evolution in Barrett's adenocarcinoma cells: critical roles of elevated hsRAD51, homologous recombination and Alu sequences in the genome.

A prominent feature of most cancers including Barrett's adenocarcinoma (BAC) is genetic instability, which is associated with development and progression of disease. In this study, we investigated the role of recombinase (hsRAD51), a key component of homologous recombination (HR)/repair, in evolving genomic changes and growth of BAC cells. We show that the expression of RAD51 is elevated in BAC cell lines and tissue specimens, relative to normal cells. HR activity is also elevated and significantly correlates with RAD51 expression in BAC cells. The suppression of RAD51 expression, by short hairpin RNA (shRNA) specifically targeting this gene, significantly prevented BAC cells from acquiring genomic changes to either copy number or heterozygosity (P<0.02) in several independent experiments employing single-nucleotide polymorphism arrays. The reduction in copy-number changes, following shRNA treatment, was confirmed by Comparative Genome Hybridization analyses of the same DNA samples. Moreover, the chromosomal distributions of mutations correlated strongly with frequencies and locations of Alu interspersed repetitive elements on individual chromosomes. We conclude that the hsRAD51 protein level is systematically elevated in BAC, contributes significantly to genomic evolution during serial propagation of these cells and correlates with disease progression. Alu sequences may serve as substrates for elevated HR during cell proliferation in vitro, as they have been reported to do during the evolution of species, and thus may provide additional targets for prevention or treatment of this disease.

Laparoscopically assisted transsacral resection of rectal cancer with primary anastomosis. A preliminary review.

BACKGROUND: The management of rectal cancer has been changing to include more sphincter-sparing procedures. We report our initial experience with a new technique incorporating laparoscopy and a transsacral approach for low or midlevel rectal cancer. Here, we tried to determine whether this sphincter-sparing method could produce acceptable morbidity and recurrence rates. METHODS: Patients with rectal cancer 4 to 8 cm from the dentate line underwent laparoscopically-assisted transsacral resection (LTR) with primary anastomosis. With this technique, the rectosigmoid is mobilized via laparoscopy while the patient is in the supine position. Next, the patient is placed in the prone jackknife position, and a segment of rectum is resected by a transsacral approach. Age, estimated blood loss, length of time in the operating room, length of stay, and postoperative complications were noted. Aspects of the tumor pathology regarding stage, lymph nodes, tumor size, and presence of tumor at resection margins also were recorded. RESULTS: A total of 13 patients, ages 26 to 70 years (mean, 52.5 years), underwent the procedure. No perioperative deaths occurred. The mean hospital stay was 9.6 days. The average size of the rectal lesion was 4.3 cm in the largest dimension. The average specimen contained 11.5 total, and 2.0 metastatic lymph nodes. Postoperative complications included two anastomotic breakdowns and two other wound complications. Late follow-up evaluation ranged from 10 to 30 months, with 11 of 13 patients alive (85% survival). Two local recurrences and three distant recurrences were noted at long-term follow-up assessment. CONCLUSIONS: In selected patients with low or midlevel rectal cancer, LTR may be a viable option. Further experience is necessary to define its oncologic efficacy and whether routine temporary diverting colostomy is indicated.

Affinity purification of DNA and RNA from environmental samples with peptide nucleic acid clamps.

Bispeptide nucleic acids (bis-PNAs; PNA clamps), PNA oligomers, and DNA oligonucleotides were evaluated as affinity purification reagents for subfemtomolar 16S ribosomal DNA (rDNA) and rRNA targets in soil, sediment, and industrial air filter nucleic acid extracts. Under low-salt hybridization conditions (10 mM NaPO(4), 5 mM disodium EDTA, and 0.025% sodium dodecyl sulfate [SDS]) a PNA clamp recovered significantly more target DNA than either PNA or DNA oligomers. The efficacy of PNA clamps and oligomers was generally enhanced in the presence of excess nontarget DNA and in a low-salt extraction-hybridization buffer. Under high-salt conditions (200 mM NaPO(4), 100 mM disodium EDTA, and 0.5% SDS), however, capture efficiencies with the DNA oligomer were significantly greater than with the PNA clamp and PNA oligomer. Recovery and detection efficiencies for target DNA concentrations of > or =100 pg were generally >20% but depended upon the specific probe, solution background, and salt condition. The DNA probe had a lower absolute detection limit of 100 fg of target (830 zM [1 zM = 10(-21) M]) in high-salt buffer. In the absence of exogenous DNA (e.g., soil background), neither the bis-PNA nor the PNA oligomer achieved the same absolute detection limit even under a more favorable low-salt hybridization condition. In the presence of a soil background, however, both PNA probes provided more sensitive absolute purification and detection (830 zM) than the DNA oligomer. In varied environmental samples, the rank order for capture probe performance in high-salt buffer was DNA > PNA > clamp. Recovery of 16S rRNA from environmental samples mirrored quantitative results for DNA target recovery, with the DNA oligomer generating more positive results than either the bis-PNA or PNA oligomer, but PNA probes provided a greater incidence of detection from environmental samples that also contained a higher concentration of nontarget DNA and RNA. Significant interactions between probe type and environmental sample indicate that the most efficacious capture system depends upon the particular sample type (and background nucleic acid concentration), target (DNA or RNA), and detection objective.

The syndromes of Sotos and Weaver: reports and review.

The syndromes of Sotos and Weaver are paradigmatic of the daily nosologic difficulties faced by clinical geneticists attempting to diagnose and counsel, and to give accurate prognoses in cases of extensive phenotypic overlap between molecularly undefined entities. Vertebrate development is constrained into only very few final or common developmental paths; therefore, no developmental anomaly seen in humans is unique to ("pathognomonic" of) one syndrome. Thus, it is not surprising that prenatal overgrowth occurs in several syndromes, including the Sotos and Weaver syndromes. Are they sufficiently different in other respects to allow the postulation of locus (rather than allele) heterogeneity? Phenotypic data in both conditions are biased because of ascertainment of propositi, and the apparent differences between them may be entirely artificial as they were between the G and BBB syndromes. On the other hand, the Sotos syndrome may be a cancer syndrome, the Weaver syndrome not (though a neuroblastoma was reported in the latter); in the former there is also remarkably advanced dental maturation rarely commented on in the latter. In Weaver syndrome there are more conspicuous contractures and a facial appearance that experts find convincingly different from that of Sotos individuals. Nevertheless, the hypothesis of locus heterogeneity is testable; at the moment we are inclined to favor the hypothesis of allele heterogeneity. An international effort is required to map, isolate, and sequence the causal gene or genes.

Pseudocysts and pseudoaneurysms: surgical strategy.

Eight patients over an 8-year period required operation for spontaneous hemorrhage as a complication of a pancreatic pseudocyst. Three patients presented with abdominal pain or jaundice and bled in hospital while undergoing work-up. Four patients were admitted with upper gastrointestinal bleeding and one with intraperitoneal bleeding. Five patients were managed by pancreatic resection (two of the head and three of the tail) and three were managed by arterial ligation and internal drainage. There was one death (mortality rate, 12.5%). The first four patients in the series had their operations delayed secondary to a perceived need for further work-up or an inability to make an exact diagnosis of the bleeding site. All rebled, necessitating an emergency operation. The last four patients underwent an expedited workup and operation. Successful treatment of bleeding pancreatic pseudocysts requires good surgical judgment, especially when nonoperative methods fail or aren't applicable. The risk of recurrent hemorrhage is high, suggesting the need for immediate intervention once the diagnosis is made. Resection provides definitive control, although selected patients with easily accessible vessels may be managed more conservatively with ligation and drainage.

Bleeding gastroduodenal ulcers: improved outcome from a unified surgical approach.

We have adopted a uniform, aggressive approach to the management of upper gastrointestinal hemorrhage. Our protocol consists of admission to a surgical service, endoscopy within 24 hours, and liberal use of intensive care monitoring. Urgent or emergency surgery is recommended for the following criteria: 1) presence of shock upon admission; 2) resuscitation requirements of greater than 4 units of blood; 3) age 65 years or older; 4) ulcer size greater than 2 cm or with stigmata of recent hemorrhage; or 5) history of a previous admission for an ulcer complication. During the period 1986-1990, 66 patients met the criteria for operation. There were 45 males and 21 females with an average age of 53.5 years (range, 29-84). Thirty-seven bled from a gastric ulcer and 29 from a duodenal ulcer. They were transfused an average of 5.0 units of blood (range, 0-13). There were no hospital deaths, but 11 patients (16.7%) had 12 postoperative complications. We conclude that a unified, single team approach to gastroduodenal hemorrhage with expedited work-up and early operation prevents death from this treatable condition.

Differential diagnosis and management of unexplained bleeding.

A brief overview of normal hemostasis is reviewed. Congenital and acquired causes of bleeding are discussed. Methods for evaluation of the coagulation system of the patient prior to an operative procedure are outlined. A strategy for characterizing intraoperative bleeding disorders and appropriate interventions are discussed.

Alternatives in the surgical management of in situ breast cancer. A meta-analysis of outcome.

The surgical management of lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) remains controversial. For in situ breast cancer local excision (LE), local excision and radiation therapy (LERT) and mastectomy (MAST) have all been advocated. A search of the English literature found 13 reports concerning the surgical management of LCIS and 12 reports concerning the management of DCIS. The data were combined in a meta-analysis of outcome. As expected, recurrence rates following LE with both LCIS 8.4%) and DCIS (17%) are high. However,the overall mortality following mastectomy for recurrence, LCIS (2.8%) and DCIS (2.3%) does not differ statistically from those treated initially with mastectomy for LCIS (0.9%) and DCIS (1.7%). We conclude from these data that local recurrence after breast conserving procedures for in situ breast cancer does not carry an ominous prognosis. This knowledge should aid in planning individual therapy.

The impact of technology on the management of pancreatic pseudocyst. Fifth annual Samuel Jason Mixter Lecture.

The records of 299 patients with 357 admissions for pancreatic pseudocysts seen between 1960 and 1989 were studied; 233 patients underwent operation. The natural history of pancreatic pseudocysts has been clarified by newer technology, such as ultrasonography, computer tomography, amylase isoenzyme measurements, and endoscopic retrograde cholangiopancreatography. All have influenced diagnosis, nonoperative management, and surgical operation. Differences between pancreatic pseudocysts associated with acute pancreatitis in contrast with chronic pancreatitis, and the complications of obstruction, hemorrhage, rupture, pancreatic ascites, infection, and jaundice can now be more rationally treated. Pancreatic pseudocysts and pancreatic ductal changes are now revealed earlier, especially by endoscopic retrograde cholangiopancreatography. Paradoxically, this information has encouraged nonoperative conservative therapy and also larger operations, eg, resection and adjunctive pancreaticojejunostomy. Partial resection of the pancreas together with the pancreatic pseudocysts was performed in 58 (25%) of the 233 patients. Recent technology permits cautious exploration of selective pancreatic pseudocyst drainage percutaneously or transgastroduodenally avoiding laparotomy.

Percutaneous Denver peritoneovenous shunt insertion.

A simplified technique for insertion of a peritoneovenous shunt is described. By using a "peel-away" sheath at both ends of the shunt, the insertion is much quicker and less traumatic to the patient.

A community survey of the potential use of thrombolytic agents for acute myocardial infarction.

We surveyed all patients admitted to nine community hospital coronary care units to determine what proportion could be candidates for thrombolytic therapy. During the 12-month study period, there were 4,115 admissions for possible acute myocardial infarction, and 1,076 (26%) had a discharge diagnosis of myocardial infarction. Patients with myocardial infarction had the following characteristics: 60% had ST elevation seen on the first ECG, 17% had ST depression without ST elevation, 75% were less than 75 years old, 75% had no contraindications to thrombolytic therapy, 78% arrived at hospital within six hours of onset of symptoms, and 94% arrived within 24 hours of symptoms. Criteria for administration of thrombolytic therapy can be grouped as restrictive (arrival within six hours of symptoms and ST elevation) or liberal (arrival within 24 hours of symptoms and ST elevation or ST depression). Applying these characteristics, 26% met restrictive criteria for treatment with thrombolytic therapy, and 36% met liberal criteria. Until liberal criteria (therapy up to 24 hours and ST depression) are convincingly shown to be of benefit, we believe clinicians should apply restrictive criteria to potential candidates for thrombolytic therapy.

Peritoneovenous shunt (PVS) for malignant ascites. An analysis of outcome.

Fifty cases of malignant ascites were studied to determine what factors influenced outcome after peritoneovenous shunt. There were 36 women and 14 men. The five most common tumor types were colon, breast, gastric, pancreatic, and unspecified adenocarcinoma. Multivariate analysis between those patients surviving longer than 7 weeks (n = 20) and those who died in less than 7 weeks (n = 30) showed that women did uniformly better than men, even excluding the "female malignancies" (P less than 0.01). An elevated white blood cell count (WBC) and low platelets also were strong predictors of poor outcome (P less than 0.5 for difference in means between the two groups). Patients with pancreatic cancer and ascites fared poorly (80% mortality by 7 weeks) as did those with colon cancer (73% mortality by 7 weeks). By contrast, 50 per cent of the patients with breast and gastric cancer lived more than 7 weeks. Twelve patients had a LaVeen shunt placed, compared with 38 who had a Denver shunt. Fifty per cent of the La Veen shunts failed, with a mean time to failure of 69 days (P less than 0.01). Shunt failure, however, had no influence on overall survival.

Percutaneous endoscopic gastrostomy. New technique--old complications.

Early reports support the percutaneous endoscopic gastrostomy (PEG) as an alternative to traditional gastrostomy with lower cost, greater ease of placement, and low morbidity and mortality. The authors' bias has been to attempt PEG on nearly all patients referred to gastrostomy tube prior to performing open gastrostomy. In this light, we reviewed our 32 month experience of 115 PEG placements in 112 adult patients, with a mean follow-up of 59.4 days. Placement was unsuccessful in ten per cent of patients and difficult in another six per cent. Minor postoperative complications not requiring intervention occurred in 9.5 per cent of patients, and major complications in 20 per cent. Infection was the most common postoperative problem. Thirty day mortality was 24 per cent. No patient died as a direct result of the procedure. The ten per cent failure rate is a consequence of attempting PEG as the initial procedure in greater than 90 per cent of patients. PEG can be employed as an initial procedure in even the sickest of patients with a high rate of success, and morbidity comparable to open gastrostomy. This knowledge allows early PEG placement in all types of patients, thereby facilitating their transfer to a non-acute care environment.

Colon cancer: surgical therapy.

Successful treatment of colon cancer is founded on surgical resection of the primary lesion and the regional lymph nodes. The significant number of patients so resected who experience no recurrence, even with positive lymph nodes, indicates that the disease still was confined regionally and that the therapy was effective. Cancer in about 50 per cent of patients does recur, however, and, outside of a small proportion who can be resected again, all patients with recurrence die. There is virtually no curative nonsurgical therapy for colorectal carcinoma.

Surgical management of pseudomembranous colitis.

The authors recently studied two cases of pseudomembranous colitis (PMC) that required surgery and combined them with previously reported cases in the literature, which required surgery to propose guidelines for the surgical management of PMC. A total of 21 patients were studied. Indications for surgery included refractory disease in seven patients, toxic megacolon in 12 patients, and perforation in two patients. Operative management ranged from decompressive cecostomy to total proctocolectomy. The best results were obtained with subtotal colectomy and ileostomy. It is concluded that PMC should be managed surgically in a manner analogous to ulcerative colitis. If there is no improvement after 7 days of aggressive medical management, surgical intervention, ileostomy with subtotal colectomy is indicated to prevent complications. Complications of PMC, toxic megacolon and perforation, should also be managed with ileostomy and subtotal colectomy as simple decompression or segmental resection does nothing to alter the underlying disease process.

Gastrojejunostomy: is it helpful for patients with pancreatic cancer?

A retrospective review of palliative outcome of gastrojejunostomy in patients with pancreatic cancer was conducted. Eighty-one patients were analyzed in two groups depending on duodenal patency. Forty-five patients (group I) had no evidence of duodenal obstruction. Thirty-six patients (group II) had evidence of impingement on the duodenum by the pancreatic cancer. A third subset of patients was also studied for outcome. These 21 patients (five group I and 16 group II) had nausea and vomiting as major symptoms and were judged to have the most to gain from gastrojejunostomy. Patients were categorized by outcome. Poor outcome was defined as either death during the hospitalization for gastrojejunostomy or death within 30 days of operation even if the patient left the hospital. Risk for poor outcome depended on group. In group I, 18 of 45 patients (40%) had a poor outcome compared with 25 of 36 (70%) patients in group II (p less than 0.001). Nineteen of the 21 (90%) patients with nausea and vomiting had a poor outcome. It is an unfortunate paradox that the more patients need gastrojejunostomy for pancreatic cancer, the less likely they are to have a favorable outcome. Gastric outlet obstruction in pancreatic cancer appears to be a terminal event. A prospective study is needed to see if any true palliation of vomiting can be affected in these patients.

Analysis of hyperamylasemia in patients with severe head injury.

To evaluate the influence of severe head injury (SHI) on amylase activity, we studied the amylase profile of 60 patients with SHIs and Glasgow Coma Scores less than 10. Fourteen additional multiple trauma patients without head injuries were studied as a control group. We excluded patients with pancreatic injury and abdominal trauma. Total serum amylase (TA), pancreatic isoamylase (PA), and nonpancreatic isoamylase (NPA) levels were measured on Days 0, 2, 4, 7, and 14 postinjury. Values greater than 2 SD above the normal mean were considered elevated. All SHI patients were comatose; 14 died. In the SHI group, TA increased in 23 patients, PA increased in 40, and NPA increased in 14. The source of hyperamylasemia was PA in 14, NPA in one, and mixed in 8 patients. While PA increases occurred throughout the study, NPA elevations occurred early. These increases did not correlate with shock (BP less than 80 mm Hg; 17 patients), facial trauma (24 patients), or associated injury (29 patients). On Day 7 postinjury, the mean TA (215 du%) and the mean PA (203.8 du%) were significantly elevated in the SHI patients compared to controls (122.1 du%, P less than 0.05, Wilcoxon's rank sum test). These data indicate that serum amylase is not a reliable index of pancreatic injury in patients with SHI. Severe head injury and multiple trauma activate pathways that increase amylase levels in the blood, suggesting a central nervous system regulation of serum amylase levels.

Usefulness of selective preoperative chest x-ray films. A prospective study.

Preoperative screening chest x-ray studies continue to be used widely despite the high cost and reported low-yield. Most physicians now use "clinical judgment" to mitigate the frequency of chest x-ray. To determine the usefulness of "selective" preoperative chest x-ray studies, 403 consecutive patients undergoing operation were prospectively studied. Chest x-ray films were analyzed both for abnormality and the frequency with which the changes seen on x-ray films led to cancellation of surgery or resulted in a further evaluation of the pathology discovered. There were 228 male and 175 female patients, (average age: 54 years). A total of 166 (41%) patients had operations performed without a preoperative chest x-ray study. The x-ray studies on 136 of the 237 patients who had preoperative chest x-ray were considered normal. A variety of abnormalities such as effusion, cardiomegaly, atelectasis, or granuloma were found in the remaining 101 patients. Sixty-four of these patients were known from previous studies to have the abnormality that was recorded. Eight of 37 (21%), who had surgery as scheduled, subsequently underwent evaluation for the new pulmonary problem detected on x-ray films. Only two operations were cancelled as a result of the screening x-ray. The majority of abnormalities detected were already known or were considered insufficient for further evaluation. In a metropolitan area of Michigan the cost for a chest x-ray is $70. Projected nationwide, more than $1 billion could be saved on needless "selective" preoperative chest x-ray studies each year. These data suggest that preoperative chest x-ray is still widely overused.(ABSTRACT TRUNCATED AT 250 WORDS)