Mantle cell lymphoma: observation to transplantation.

Mantle cell lymphoma as a rare non-Hodgkin B-cell lymphoma can present in different clinical presentations such as an aggressive form or a more indolent picture. Treatment modality is based on multiple factors including age, presence or absence of symptoms, and comorbidities. Watchful waiting is a reasonable approach for asymptomatic patients especially in elderly. In symptomatic patients, treatment is chemo-immunotherapy followed by maintenance immunotherapy or autologous bone marrow transplant. Allogeneic bone marrow transplant has a potential benefit of cure for relapsed/refractory cases, but it has a high mortality rate. Novel treatment with agents such as ibrutinib, a Bruton tyrosine kinase inhibitor, has shown promising results in relapse/refractory cases. We extensively review the most recent data on diagnostic and therapeutic management of mantle cell lymphoma through presenting two extreme clinical scenarios.

Urothelial bladder carcinoma with choriocarcinomatous differentiation presenting with a false-positive pregnancy test.

Urothelial carcinoma of the bladder with choriocarcinomatous features is a rare presentation among genitourinary cancers. In this study, the case of a 42-year-old woman who presented with menstrual irregularity and positive urine and serum beta-human chorionic gonadotropin tests is presented. Pelvic ultrasound showed no intrauterine pregnancy. Laparoscopy and hysteroscopy with dilatation and curettage were negative for evidence of trophoblastic tissue. Computed tomography of the abdomen and pelvis showed an intravesical fundal mass, with no evidence of extravesical disease. Cystoscopy and transurethral resection of the bladder tumor diagnosed an invasive high-grade urothelial carcinoma with trophoblastic differentiation and multiple foci of choriocarcinomatous morphology. The patient received 3 cycles of neoadjuvant chemotherapy with methotrexate, vinblastine, adriamycin and cisplatin and then underwent partial cystectomy, which was negative for any residual tumor. This is the first reported case of a positive urine pregnancy test leading to the diagnosis of urothelial carcinoma.

Iron infusion and deposition in the kidney.

BACKGROUND: Parenteral iron therapy is the mainstay of treating iron deficiency anemia in chronic kidney disease (CKD) patients. METHODS: Retrospective case study of iron staining of renal tissues in 2 CKD patients who had received intravenous iron prior to the renal biopsy. RESULTS: Following the infusion of ferumoxytol, iron staining of renal biopsy demonstrated blue curvilinear deposition of iron in the tissue macrophages (histocytes) and interstitium of the kidney. Renal iron deposition was not observed in a patient administered intravenous iron dextran. CONCLUSION: We postulate that the higher molecular weight of ferumoxytol and different carbohydrate components may lead to deposition and trapping of the ironcarbohydrate complexes in the reticuloendothelial system of the kidney. Potential renal toxicity from iron induced oxidant stress, especially in patients with underlying chronic kidney disease, merits further investigation.

Descriptive epidemiology of gastric adenocarcinoma in the state of Texas by ethnicity: Hispanic versus White non-Hispanic.

BACKGROUND: We aimed to evaluate the clinicopathological and demographic characteristics of gastric adenocarcinoma in Hispanics and compare these trends with those found in non-Hispanic Whites in Texas. METHODS: Records of patients with gastric adenocarcinoma found in the Texas Cancer Registry from 1995 to 2006 were reviewed. Four ethnic-geographic groups were formed: Hispanics residing in El Paso County (a county on the Texas-Mexico border), White non-Hispanics in El Paso County, Hispanics from the remaining counties of Texas combined, and White non-Hispanics from the remaining counties of Texas combined. Adjusted prevalence ratios (PRs) for the outcome of late stage at diagnosis were calculated. RESULTS: Of 9949 patients, 561 patients were El Paso County residents, of whom 83% were Hispanics. Among the four ethnic-geographic groups, the age-adjusted incidence was the highest in Hispanics in El Paso County (15.5 cases/100000). Tumor pathobiology varied by ethnicity. White non-Hispanics were more likely than Hispanics to have a proximal tumor and less likely to have a poorly differentiated or undifferentiated tumor. In El Paso County, patients in each of the eight age groups under 75 years compared to patients aged ≥85 years were significantly more likely to be at late stage (adjusted PRs 1.44-1.71). CONCLUSION: The incidence of gastric adenocarcinoma is higher in Hispanics than in Whites in both El Paso County and the remaining portion of Texas. Hispanics have a higher grade of gastric adenocarcinoma. The prevalence of late stage at the time of diagnosis is higher in younger patients than in older patients.

How does an enzyme recognize CO2?

Phosphoenolpyruvate carboxykinase (PCK) reversibly catalyzes the carboxylation of phosphoenolpyruvate to oxaloacetate. Carbon dioxide, and not bicarbonate ion, is the substrate utilized. Assays of the carboxylation reaction show that initial velocities are 7.6-fold higher when CO(2) is used instead of HCO(3)(-). Two Escherichia coli PCK-CO(2) crystal structures are presented here. The location of CO(2) is the same for both structures; however the orientation of CO(2) is significantly different, likely from the presence of a manganese ion in one of the structures. PCK and the other three known protein-CO(2) crystal structure complexes have been compared; all have CO(2) hydrogen bonding with a basic amino acid side chain (Arg65 or Lys213 in PCK), likely to polarize CO(2) to make the central carbon atom more electrophilic and thus more reactive. Kinetic studies found that the PCK mutant Arg65Gln increased the K(M) for substrates PEP and oxaloacetate but not for CO(2). The unchanged K(M) for CO(2) can be explained since the Arg65Gln mutant likely maintains a hydrogen bond to one of the oxygen atoms of carbon dioxide.