Genomic loci associated with performance limiting equine overriding spinous processes (kissing spines)

Commonly known as "Kissing Spines" (KS), the pathological mechanisms underlying impingement and overriding of spinous processes (ORSPs) in horses are poorly understood. Thoroughbreds, Warmbloods, and stock-type breeds, including Paint Horses and Quarter Horses are at increased risk for developing clinical signs of KS. A total of 155 stock-type and Warmblood horses presented at collaborating veterinary clinics and hospitals were examined using a strict clinical and radiographical phenotyping scheme to grade each horse from 0 for unaffected controls to 4 for severe KS. Following genotyping with the Illumina Equine SNP70 array (Illumina, Inc.) a Genome Wide Association Study (GWAS) using 61,229 filtered individual Single Nucleotide Polymorphisms (SNPs) was performed to the KS grade phenotype. Two significantly associated SNPs (BIEC2-668062 and BIEC2-668013) on chromosome 25 defined a ~1.4 Gb candidate region containing approximately 17 coding genes (EquCab3) and 195 ENSEMBL annotated variants. Investigation of the best associated SNP (BIEC2-668062) on chr25 demonstrates a significant correlation with an increase in one KS grade, on average, per A allele in this population. A significant effect of breed group, age, height or sex was not observed in this population. These preliminary results demonstrate the potential for KS diagnosis and preventative measures for WB/ST individuals supported by increased genetic risk for more severe KS grade. We propose further research including other affected breeds and evaluating causative variants, as well as the effect of BIEC2-668062 in these populations.

Formulating a global prognosis and treatment plan for the periodontally compromised patient: a reconstructive vs. an adaptive approach

The clinician faces treatment planning challenges when patients present with generalized severe chronic periodontitis that may result in tooth loss. This article provides a treatment planning discussion along with approaches for treating such patients. It presents the clinical question: What is the best means for approaching treatment planning in a patient with severe periodontitis requiring extraction and replacement of some teeth? Two treatment approaches are discussed—a reconstructive approach versus an adaptive one—both of which have an end goal of achieving periodontal health and occlusal stability, and each has its own advantages and disadvantages. In conclusion, utilizing a global prognostic approach will assist clinicians anticipate the eventual restorative needs of patients and prescribe customized periodontal and restorative therapies that best address those needs.

Radiotherapy, concomitant protracted-venous-infusion 5-fluorouracil, and surgery for ultrasound-staged T3 or T4 rectal cancer

BACKGROUND

A prospective study was undertaken to evaluate the response and toxicity of neoadjuvant chemoradiotherapy for ultrasound-staged T3 or T4 rectal cancer.

PATIENTS AND METHODS

Since 1995, 30 patients (18 males; median age, 56 (range, 25-83) years) have received preoperative chemoradiotherapy for ultrasound-staged T3 or T4 rectal cancer. All patients underwent an endorectal ultrasound, CT scan, and review in our multidisciplinary Gastrointestinal Tumor Board before treatment. All patients had pathology-demonstrated invasive adenocarcinoma of the rectum. Eleven patients were Stage T3N0, 14 were T3N1, and five were T4N1. Patients received radiotherapy to the primary tumor and draining lymph nodes (45 Gy) followed by a tumor boost (50.4-54 Gy). Protracted-venous-infusion 5-fluorouracil (225 mg/m2 per day, seven days per week) was administered throughout treatment. Surgical resection was performed six to ten weeks after completing chemoradiotherapy. Using endorectal ultrasound measurements, the primary tumor was a median of 4 (range, 0-12) cm from the anal verge, encompassed 50 (range, 20-90) percent of the rectal circumference, and was 6 (range, 3-12) cm in diameter.

RESULTS

No Grade 4 toxicity was observed during chemoradiotherapy. Three patients experienced Grade 3 toxicity (diarrhea), and four patients required a treatment interruption of greater than three days. All patients completed at least 90 percent of the prescribed radiotherapy dose. All patients underwent surgical resection. Ninety-four percent had clear surgical margins. All pathologic specimens had significant evidence of necrosis, hyalinization, and fibrosis. Thirty-three percent of the specimens had a complete pathologic response (defined as no evidence of viable tumor cells). Of the 19 patients with ultrasound-staged N1 disease, only five had pathologic evidence of nodal involvement after chemoradiotherapy. Of the 25 patients with ultrasound-staged T3 disease, pathologic staging revealed eight with T0, two with T1, five with T2, and ten with T3 disease. Of the five patients with ultrasound-staged T4 disease, pathologic staging revealed two with T0, one with T2, and two with T3 disease. No patient developed progressive disease while on treatment. Two patients have experienced local failure at 6 and 20 months, and one patient failed in the liver at seven months. Twenty-seven patients remain free of disease with a median follow-up of 20 (range, 3-53) months.

CONCLUSION

Our experience suggests that preoperative chemoradiotherapy is well tolerated, down-stages tumors, and sterilizes regional lymph nodes.

Pancreatic tumors show high levels of hypoxia

PURPOSE

Because of the dismal outcomes of conventional therapies for pancreatic carcinomas, we postulated that hypoxia may exist within these tumors.

METHODS AND MATERIALS

Seven sequential patients with adenocarcinomas of the pancreas consented to intraoperative measurements of tumor oxygenation using the Eppendorf (Hamburg, Germany) polargraphic electrode.

RESULTS

All 7 tumors demonstrated significant tumor hypoxia. In contrast, adjacent normal pancreas showed normal oxygenation.

CONCLUSION

Tumor hypoxia exists within pancreatic cancers.

Highly active antiretroviral therapy results in HIV type 1 suppression in lymph nodes, increased pools of naive T cells, decreased pools of activated T cells, and diminished frequencies of peripheral activated HIV type 1-specific CD8+ T cells

This study examines sequential lymph nodes from 13 drug-naive patients before and after 24 weeks of highly active antiretroviral therapy (HAART). A multipronged approach was used to study changes in HIV-1 RNA in each paired lymph node in relation to tissue architecture and frequency of naive T cells. After 24 weeks, all patients showed significant suppression of plasma viral load and 12 of 13 showed concordant viral suppression in the lymph node (p = 0.001). Using in situ hybridization and quantitative image analysis, we showed that HIV-1 RNA was reduced to below detectable levels (two copies per cell) in follicular dendritic cell (FDC) and mononuclear cell pools. Independent immunohistochemical analysis of lymph node sections revealed that 5 of 13 patients displayed increased FDC networks and 6 of 13 showed no change and all patients showed increases in tissue-resident CD4+ cells. All lymph node biopsies at 24 weeks showed increased proportions of CD4+ and CD8+ cells coexpressing the naive markers CD45RA and CD62L when compared with baseline values. Significant correlations existed between viral load suppression and loss of activated CD8+ T cells after 24 weeks in both lymph node and blood, which was mirrored by significantly lowered frequencies of activated peripheral Gag peptide/MHC tetramer+ CD8+ cells. Overall, these data show that a potent and successful treatment strategy that significantly suppresses and removes FDC-resident HIV-1 results in improvements in lymphoid architecture and by so doing provides the structures available for increased numbers of naive cells to interact with cognate antigen. In addition, our article shows that suppression of HIV-1 replication results in diminished frequencies of peripherally activated antigen-specific CD8+ cells.

Clinical presentation of mucin-secreting tumors of the pancreas

BACKGROUND

Pancreatitis and jaundice secondary to ductal obstruction are common in intraductal papillary mucinous tumors (IPMT) of the pancreas. However, the incidence and severity of the complications of obstruction are not well documented. The aim of the study was to investigate the clinical presentation and outcome of 10 patients with IPMT.

METHODS

All cases of IPMT diagnosed between 1994 and 1999 were reviewed.

RESULTS

Four of the 10 patients developed severe acute illness with systemic complications resulting from ductal obstruction. Three suffered acute cholangitis with sepsis, and 1 developed necrotizing pancreatitis and ARDS. There was 1 postoperative death in a patient with adenocarcinoma. All other patients are alive and well with a median follow-up of 26 months (survival 90%).

CONCLUSIONS

Pancreatic or common bile duct obstruction in IPMT may result in acute, life-threatening disease. Aggressive surgical therapy is warranted before development of complications of ductal obstruction or progression of tumor occurs.

Lymph node human immunodeficiency virus RNA levels and resistance mutations in patients receiving high-dose saquinavir

The development of resistance mutations and human immunodeficiency virus (HIV) RNA levels were compared in lymph nodes and plasma of patients receiving antiretroviral therapy. Ten HIV-positive patients receiving high-dose saquinavir monotherapy (3600 or 7200 mg/day) underwent 14 lymph node biopsies before and during therapy. HIV RNA levels and appearance of resistance mutations to saquinavir were determined in simultaneous lymph node and plasma samples. HIV RNA levels were found to be consistently higher (mean, 3.16 log RNA copies; SD, 1.04; range, 2.23-5.59) in lymph nodes than in simultaneous plasma samples. Saquinavir therapy resulted in a reduction in HIV RNA levels in both plasma and lymph nodes. The presence or absence of a resistance mutation to saquinavir at codons 48 or 90 of the HIV-1 protease gene was identical in 13 of 14 biopsies, suggesting that resistance mutations to saquinavir appear within close temporal proximity in lymph nodes and plasma.

Rainbow Universal CPG: a versatile solid support for oligonucleotide synthesis

We have developed a universal solid support, termed Rainbow Universal CPG, for use in automated oligonucleotide synthesis. The universal solid support allows any oligodeoxyribonucleotide sequence to be synthesized from a single type of controlled pore glass (CPG) support. Deprotection of oligodeoxyribonucleotides was optimized using 0.5 M LiCl in concentrated ammonium hydroxide. PCR experiments using three different sets of primers proved that the 3'-hydroxyl function of oligodeoxyribonucleotides synthesized from Rainbow Universal CPG was retained. This universal solid support shows promise for replacing the standard nucleoside CPG supports.

Minimally invasive surgery

With the widespread introduction of laparoscopic cholecystectomy in late 1989, the practice and expectations of general surgery were changed forever. The techniques of laparoscopy were not new--they had been adopted by gynecologists and orthopedic surgeons at least a decade before--but it was laparoscopic cholecystectomy that captured the attention of the surgical profession and the public and spawned the tremendous growth in what has come to be called minimally invasive surgery. Although this surgery has tremendous appeal, offering quicker recovery, less pain, and possibly greater safety, it presents new challenges in the areas of training, credentialing, and quality assessment and raises serious questions about the real benefits of new technology at a time when the political and economic sensitivity of these issues is greater than ever. In this chapter I limit myself to a discussion of laparoscopy in general surgery, with a focus on what we have learned from laparoscopic cholecystectomy and on what this knowledge suggests for the future of other laparoscopic general surgical procedures.

Long-term results of curative resection of "minimally invasive" colorectal cancer

PURPOSE

The aim of this study was to determine the long-term outcome after curative resection of colorectal cancers that extend only into the submucosa ("minimally invasive") and to evaluate potential histologic predictors of lymph node metastases.

METHODS

Seventy-nine patients who underwent curative resection of minimally invasive colorectal cancer and were followed for at least five years were studied retrospectively.

RESULTS

The series was comprised of 53 men and 26 women, with a mean age of 61 years. The lesion was in the colon in 47 patients and the rectosigmoid or rectum in 32 patients. Open surgery followed attempted endoscopic tumor removal in 25 patients. Lymph node metastasis, found in 11/79 patients (13.9 percent), was associated with worse outcome: 36.4 percent of node(+) patients developed recurrence, vs. only 5.9 percent of node(-) patients (P < 0.005). The cumulative survival rate was also worse in node(+) vs. node(-) patients: 72.7 percent vs. 91.1 percent at five years (P < 0.05) and 45.5 percent vs. 65.3 percent at ten years (P < 0.05). Five histopathologic characteristics were identified as risk factors for lymph node metastasis: 1) small clusters of undifferentiated cancer cells ahead of the invasive front of the lesion ("tumor budding"); 2) a poorly demarcated invasive front; 3) moderately or poorly differentiated cancer cells in the invasive front; 4) extension of the tumor to the middle or deep submucosal layer; 5) cancer cells in lymphatics. Whereas patients with three or fewer risk factors had no nodal spread, the rate of lymph node involvement with four or more risk factors was 33.3 percent and 66.7 percent, respectively.

CONCLUSIONS

Metastasis is not infrequent in "minimally invasive" colorectal cancer. Appropriate bowel resection with lymph node dissection is indicated if such a lesion exhibits more than three histologic risk factors for metastasis.

Pseudomyxoma peritonei

Pseudomyxoma peritonei results from implantation of malignant tumors or irritation from ruptured benign cysts. This disease is traditionally characterized by accumulation of mucinous ascites, relatively long survival period and absence of extraperitoneal metastases. Disease progression is difficult to predict because of the spectrum of underlying pathologic entities. Four unusual instances of pseudomyxoma peritonei are presented. An instance of the neoplasm confined to the splenic parenchyma suggests potential for hematogenous dissemination. The tumor can be limited to and extend along the retroperitoneum. Retained rectal tissue after proctocolectomy may be a possible origin of disease. Enterobronchial fistula formation is a serious long term complication. Aggressive surgical approach with resection of the bulk of disease offers the optimal palliation and prognosis.

Prognostic value of tumor "budding" in patients with colorectal cancer

From 1970 to 1985, 663 patients underwent curative resection of colon and rectal adenocarcinomas. All surgical specimens were examined for tumor "budding," defined as small clusters of undifferentiated cancer cells ahead of the invasive front of the lesion. Patients were divided into two groups according to degree of budding: none or mild (BD-1) and moderate or severe (BD-2). BD-1 occurred in 493 patients (74.4 percent), and BD-2 was found in 170 patients (25.6 percent). More severe budding was associated with worse outcome: 71.1 percent of BD-2 patients had recurrence, compared with 20.0 percent of BD-1 patients (P < 0.005). The five-year survival rate was worse in BD-2 than in BD-1 (22.2 percent vs. 70.7 percent; P < 0.001). The 10-year survival rate was also worse in BD-2 than in BD-1 (13.8 percent vs. 50.6 percent; P < 0.001). The incidence of BD-2 rose with the Dukes stage. However, the five-year survival rate of Dukes B patients with BD-2 lesions was worse than that of Dukes C patients with BD-1 cancers (29.1 percent vs. 66.2 percent; P < 0.001). Moreover, there was no difference in five-year survival among BD-1 patients with either Dukes B or C lesions (68.3 percent vs. 66.2 percent). The presence of more severe budding appears to indicate a vigorous biologic activity of colorectal cancer. Thus, meticulous follow-up--and possibly adjuvant chemotherapy--may be beneficial for patients with marked budding, regardless of their Dukes stage.

Measurement of free radicals from smoke inhalation and oxygen exposure by spin trapping and ESR spectroscopy

Research in smoke inhalation has established that free radicals are produced from gases released during combustion and these species impair lung function. Using spin traps and their adducts in an animal model free radicals were measured. Various hyperbaric oxygen regimens were tested in an attempt to attenuate pulmonary damage caused by free radical reactions. Our data demonstrated that persistent oxygen- and carbon-centered free radicals are detectable in intravascular fluids after smoke inhalation. The smoke inhalation model showed however, clearing of spin trap adducts one hour after smoke exposure. Other researchers have found that when 100% oxygen is given at 1 atmosphere absolute (ATA) for 1 h, free radicals were not detectable. However, oxygen given at 2.5 ATA does produce detectable free radicals. With continued exposure at this pressure, the levels of free radicals increase for up to 60 min. This study suggests that the level of free radical induced oxygen toxicity may be a function of oxygen pressure and duration of oxygen exposure.