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We investigate population genetic structuring in Margaritifera falcata, a freshwater mussel native to western North America, across the majority of its geographical range. We find shallow rangewide genetic structure, strong population-level structuring and very low population diversity in this species, using both mitochondrial sequence and nuclear microsatellite data. We contrast these patterns with previous findings in another freshwater mussel species group (Anodonta californiensis/A. nuttalliana) occupying the same continental region and many of the same watersheds. We conclude that differences are likely caused by contrasting life history attributes between genera, particularly host fish requirements and hermaphroditism. Further, we demonstrate the occurrence of a 'hotspot' for genetic diversity in both groups of mussels, occurring in the vicinity of the lower Columbia River drainage. We suggest that stream hierarchy may be responsible for this pattern and may produce similar patterns in other widespread freshwater species., (© 2013 John Wiley & Sons Ltd.)

Freshwater mussels (unionids) are increasingly recognized as important providers of ecosystem services, yet are among the most endangered fauna in the world. Because unionids are generally sessile and require specific fish hosts for development and dispersal, they are particularly vulnerable to habitat degradation. Surprisingly, little is known about the distribution of genetic diversity in freshwater mussels and this gap has a negative impact on taxonomy, monitoring, conservation and ecological research in these species. Here, we focus on western North American Anodonta, one of only three genera known to exist in this broad landscape and which contains three highly divergent lineages. We describe phylogeographical subdivision in the most widespread and diverse of these lineages, which includes Anodonta californiensis and Anodonta nuttalliana and occurs from Canada to Mexico. Using mitochondrial and nuclear data, we found that genetic structuring within this clade is inconsistent with morphologically based species designations, but instead follows patterns of vicariance among major hydrogeologic basins. Furthermore, there was a strong tendency for population diversity within drainage systems to increase downstream, implying greater habitat or host fish availability in this direction. Microsatellite results indicated that sampling locations were all genetically distinct, even at short distances. Many of our sample populations showed evidence of a recent demographic bottleneck, although this effect seemed to be very local and not drainage or basin-specific. This study provides a foundation for the establishment of appropriate management units and future research on adaptive differentiation and host fish relationships.

We have developed and characterized 13 microsatellite loci from a group of Anodonta species in western North America, and demonstrated their utility in populations representing two major clades in this genus. Allelic diversity and polymorphic information content were high for all loci, although these characteristics varied across populations. Deviations from Hardy-Weinberg genotypic ratios were not detected, although the estimated frequency of null alleles was high in one population for one locus. This is the first set of microsatellite loci to be developed for freshwater mussels in western North America, and will be useful for describing gene flow patterns among populations., (© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.)

Populations of the freshwater mussel genus Anodonta appear to be in a state of rapid decline in western North America, following a trend that unfortunately seems to be prevalent among these animals (Mollusca: Unionoida). Here we describe the patterns of molecular divergence and diversity among Anodonta populations in the Bonneville Basin, a large sub-basin of the Great Basin in western North America. Using amplified fragment length polymorphism (AFLP) analysis, we found a striking lack of nuclear diversity within some of these populations, along with a high degree of structuring among populations (FST = 0.61), suggesting post-Pleistocene isolation, due either to a long-term loss of hydrologic connectivity among populations or to more recent fish introductions. We also found evidence of recent hybridization in one of these populations, possibly mediated by fish-stocking practices. Using mitochondrial sequence data, we compared the Bonneville Basin populations to Anodonta in several other drainages in western North America. We found a general lack of resolution in these phylogenetic reconstructions, although there was a tendency for the Bonneville Basin Anodonta (tentatively A. californiensis) to cluster with A. oregonensis from the adjacent Lahontan Basin in Nevada. We recommend further investigation of anthropogenic factors that may be contributing to the decline of western Anodonta and a broad-scale analysis and synthesis of genetic and morphological variation among Anodonta in western North America.

Cystic lesions of the pancreas are encountered frequently in clinical practice. Cystic neoplasms of the pancreas are much less common. In order to diagnose and most effectively treat these lesions, the surgeon must understand their clinical presentation in order to plan appropriate preoperative evaluation and therapeutic intervention. The following is a descriptive outline of the most common types of cystic neoplasms of the pancreas and a discussion of their preoperative, intraoperative, and postoperative management. The goal of the paper is to provide a functional understanding of cystic neoplasms of the pancreas so that they may be recognized and appropriately treated.

Purpose: An increased incidence of multiple (synchronous and metachronous) colorectal carcinomas has been reported in hereditary nonpolyposis colorectal cancer. This review was undertaken to determine the clinical implications of multiple colorectal carcinomas in hereditary nonpolyposis colorectal cancer., Methods: A retrospective review of the records of patients in the hereditary nonpolyposis colorectal cancer registry at Roswell Park Cancer Institute who had either synchronous or metachronous colorectal carcinomas was conducted., Results: Twenty-five of 93 patients with documented pathology were found to have multiple colorectal carcinomas. The mean age at diagnosis of the index colorectal carcinoma was 46.7 (range, 28-65) years. There were 7 (7.5 percent) patients with synchronous colorectal carcinomas and 20 (21.5 percent) patients with metachronous colorectal carcinomas. Two of the seven (28.6 percent) patients with synchronous colorectal carcinomas developed a metachronous colorectal carcinoma. In the patients with metachronous colorectal carcinomas, 29 metachronous events were noted: colon (23) and rectum (6). The mean and median time interval for metachronous colorectal carcinomas were 10.9 and 11.8 (range, 1.5-43.8) years, respectively. The mean times to first, second, and third events were 11.7 (range, 1.5-43.5), 7.9 (range, 2.7-18.7), and 12.3 (range, 11.8-12.7) years, respectively. The majority of patients with metachronous colorectal carcinomas did not have stage progression at the diagnosis of the metachronous colorectal carcinomas: 13 patients had lower or same stage at first event, 4 had lower or same stage at second event, and 2 patients had lower stage at third event. Three of 20 patients with metachronous colorectal carcinomas died of their disease., Conclusion: Multiple colorectal cancers are common in hereditary nonpolyposis colorectal cancer. Even though stage progression may not be evident at diagnosis of metachronous colorectal cancer, some of these patients will nevertheless die of their disease.

Gallbladder cancer is a relatively uncommon malignancy in the United States. Its presentation is similar to that of lithic disease of the gallbladder. Laparoscopic cholecystectomy has become the method of choice for removing the gallbladder in most benign conditions. Occasionally, unsuspected gallbladder carcinoma is encountered in association with laparoscopic cholecystectomy. Overall, gallbladder cancer portends a poor prognosis. However, in select cases, a favorable outcome can be expected and the less favorable predicted expected outcome can be improved. Management of patients with gallbladder cancer in different situations is discussed: gallbladder cancer noted postoperatively on final pathology, gallbladder cancer noted after removal of the gallbladder and opening of the specimen at the time of surgery, difficulty encountered at the time of dissection and resultant suspicion of gallbladder cancer, and diagnosis of extensive disease at initial placement of the laparoscope. The technique of extended cholecystectomy is outlined.

Background: The evaluation of AIDS patients with acute abdominal complaints (AAC) is quite difficult, and surgical intervention is associated with a high complication rate. The intent of this study is to evaluate the application of laparoscopy in the diagnosis and treatment of AIDS patients with AAC., Methods: This is a retrospective analysis of 10 consecutive AIDS patients who presented with AAC. Each had evaluation by a surgical team with subsequent laparoscopic intervention. The charts were reviewed for age, sex, time with AIDS, AIDS comorbidities, evaluation modalities, findings, treatment modalities, and outcome., Results: Laparoscopy resulted in the successful surgical treatment of four patients, diagnosis of medically treatable conditions in four patients, and alteration of the incision site in the remaining two patients. Each patient thus received direct benefit from laparoscopy. Two complications, in the converted patients, and no mortalities were encountered., Conclusions: Laparoscopy is a safe and effective interventional modality in the diagnosis and treatment of AAC in the AIDS patient.

Eosinophilic gastroenteritis is a quite uncommon clinical entity usually involving the stomach or small bowel. Occasionally, the colon is involved. We have encountered a case of eosinophilic colitis leading to a left-sided colocolonic intussusception and subsequent large bowel obstruction. This is a unique presentation that, to our knowledge, has not been previously reported. We present our case in detail as well as a review of the literature to better understand this rare clinical entity.

Pheochromocytomas are functioning paragangliomas often presenting with paroxysmal hypertension due to catecholamine secretion. The preferential diagnostic workup includes urine and serum catecholamine measurements. Therapeutic management consists of pharmacologic cardiovascular manipulation and volume expansion with subsequent surgical resection. We have encountered a symptomatic pheochromocytoma in a chronic renal insufficiency patient on hemodialysis. The diagnostic dilemma arose due to the patient's anuric status and the inherent increase in serum catecholamine levels noted in anuric patients. The therapeutic dilemma arose in the proper pharmacologic management and volume expansion in this patient on hemodialysis. The patient underwent successful resection of the pheochromocytoma and has done well. An analysis of our diagnostic and therapeutic processes as well as a review of the literature are presented to assist in the management of this difficult clinical situation.

We have undertaken a review of the small bowel carcinoids treated at Georgia Baptist Medical Center during the last 27 years in order to evaluate the clinical behavior, diagnostic approaches, treatment options, and prognosis of these neoplasms. A retrospective analysis of the tumor registry at Georgia Baptist Medical Center was undertaken. A total of 148 cases of carcinoid tumors were identified. Of these, 34 were located in the small bowel. Twenty-eight of these cases were diagnosed at our institution. The others were referred for oncology care. The patient records were reviewed for sex, race, age at presentation, location, 5-HIAA status, coexistent neoplasms, multifocality, size, metastatic status, clinical presentation, diagnostic intervention, extension, adjuvant therapy, treatment intervention, and survival. A review of the available literature was undertaken to analyze the historical results in the aforementioned categories. In retrospect, many of these tumors had been clinically active for some time. The authors outline a more aggressive workup in order to avoid acute, in extremis, and late stage presentation. We present an analysis of traditional views on survival and prognosis as related to the size and spread of small bowel carcinoid. We expect that this information will assist in the development of definitive treatment, effective adjuvant therapy, and symptomatic relief for this often frustrating neoplasm.

Background: During the last two years, laparoscopy has been utilized to facilitate the rapid, safe and direct placement of the abdominal component of ventriculoperitoneal shunts. This study was undertaken to review the feasibility, benefits, technique, and clinical application of laparoscopically assisted ventriculoperitoneal (LAVP) shunt placement., Methods: A retrospective analysis of the records of six patients who underwent LAVP shunt placement was undertaken. The sex, age, technique, indication for surgery, comorbid conditions, complications operative time, results, and mortality were noted., Results: All patients underwent successful shunt placement. This included placement in the face of previous abdominal surgery, including a percutaneous gastrostomy. The one major complication, hemothorax, was not associated with the laparoscopic portion of the procedure., Conclusions: Using basic laparoscopic skills and nonspecialized equipment, laparoscopic assistance in ventriculoperitoneal shunt placement offers easy, direct placement of the intraabdominal portion of the catheter in most situations and provides definite patient benefits.

Recognition of the mendelian dominant inherited syndrome of familial polyposis coli in the 1930s has been followed by the recognition of many inherited colonic polyposis syndromes. The recognition of different histological types of colon polyps was associated by the gradual recognition that some, such as the hamartomatous polyps, do not progress into adenocarcinoma, and others, such as various adenomas have a greater or lesser propensity to eventually give rise to invasive cancer. As the host of inherited syndromes expanded and were more widely recognized, additional inherited characteristics became apparent: such tumors as breast and thyroid associated with Cowden's syndrome, ovarian cysts and sex cord tumors with Peutz-Jeghers syndrome, and, of course, the soft tissue, bony tumors, ampullary cancers, and fibroadenomas associated with Gardner's syndrome. In recent years, genetic markers for the various syndromes have been studied, and in some cases confirmed. This whole field is rapidly developing and is briefly covered. All the steps and influencing factors in cancer development are shown in one phase or another of the polyp-cancer sequence in these inherited syndromes.

The adult rhabdomyoma (ARM) is an unusual and extremely uncommon tumor. Only 96 cases have been reported. Adult rhabdomyomas are found most often in the region of the base of the tongue, floor of the mouth, larynx, and pharynx. Uncommon locations include the soft palate, uvula, lip and cheek, orbit, and stomach. One prior case of extension of an ARM from the supraclavicular region into the mediastinum has been described as an incidental finding at autopsy. It is important to be aware of and correctly identify this tumor because total excision may be curative. Follow-up must be long-term, as recurrence can occur after 35 years. The authors present a case of an ARM diagnosed during the evaluation and treatment of a symptomatic mediastinal mass. This ARM was found to involve the esophagus and trachea from the inferior constrictors in the neck to the azygous vein in the mediastinum. This case represents a previously undescribed presentation of an ARM. We present a review of ARM and outline our diagnostic, therapeutic, and follow-up plans.