Comparing human and mouse salivary glands: A practice guide for salivary researchers

Mice are a widely utilized in vivo model for translational salivary gland research but must be used with caution. Specifically, mouse salivary glands are similar in many ways to human salivary glands (i.e., in terms of their anatomy, histology, and physiology) and are both readily available and relatively easy and affordable to maintain. However, there are some significant differences between the two organisms, and by extension, the salivary glands derived from them must be taken into account for translational studies. The current review details pertinent similarities and differences between human and mouse salivary glands and offers practical guidelines for using both for research purposes.     

Hypoxia Caused by Persistent Left Superior Vena Cava Connecting to the Left Atrium A Rare Clinical Entity

We relate the case of a 40-year-old man with a history of premature birth and dextroposition of the heart who presented for an evaluation of persistent hypoxia. An unrevealing pulmonary evaluation and agitated-saline echocardiogram led to cardiac magnetic resonance imaging. This revealed a very unusual finding: a persistent left superior vena cava with insertion into the left atrium and a small connecting vein between the right and left superior venae cavae. The implications, embryology, and pathogenesis of this rare condition are discussed.Key words: Coronary vessel abnormalities/diagnosis, embryology, heart atria/abnormalities, heart defects, congenital/diagnosis, hypoxia, magnetic resonance imaging, middle aged, vena cava, superior/abnormalitiesHypoxia as a clinical entity often has a very clear and easily identifiable cause. Here we describe the case of a patient who presented with resting hypoxia, the cause of which remained unclear after a thorough pulmonary examination and agitated-saline echocardiography. Eventually, a cardiology opinion was sought and cardiac magnetic resonance (CMR) revealed a persistent left superior vena cava (SVC). Surprisingly, this left SVC connected not to the coronary sinus, but led directly to the left atrium; the result was mild, asymptomatic hypoxia.This SVC variant with a left atrial connection is exceedingly rare—found in approximately 0.03% of the population.¹ This case and its accompanying CMR capture the variant in a fantastically clear way.     

Decompensated cirrhosis-related admissions in a large urban hospital in Uganda: prevalence,clinical and laboratory features and implications for planning patient management

Background

Cirrhosis-related complications are a major cause of morbidity and mortality in areas where its risk factors are endemic.

Objective

We determined the prevalence of decompensated cirrhosis among patients on the gastroenterology service of Mulago Hospital and described the clinical and laboratory features of these patients.

Methods

All patients admitted to the unit were assessed and their diagnosis documented. Patients with cirrhosis had clinical features of decompensation recorded. History of alcohol consumption was taken and testing for hepatitis B surface antigen (HBsAg) and hepatitis C antibody (anti-HCV) performed.

Results

Between September 2010 and January 2011, we enrolled 482 patients. The majority (53.7%) were male, overall median age 38 years. Decompensated cirrhosis was diagnosed in 85 (17.6%) patients. Of the 85 patients, 47 (55.3%) gave a history of alcohol intake, HBsAg was positive in 23 (27.1%) and anti-HCV in 3 (3.5%). Decompensation was defined by ascites among 81 (95.3%) patients, variceal bleeding in 31 (36.5%), encephalopathy in 20 (23.5%).

Conclusion

Cirrhosis is common in Mulago hospital presenting mainly with ascites and variceal bleeding. Aside from controlling causes of liver diseases, especially alcohol and hepatitis B virus infection, in the interim it is necessary to manage complications in patients who already have cirrhosis.     

Potential mechanisms for increased HIV-1 transmission across the endocervical epithelium during C. trachomatis infection

Among the now pandemic sexually transmitted infections (STIs), Chlamydia trachomatis (C. trachomatis) is the predominant bacterial pathogen and human immunodeficiency virus type 1 (HIV-1) is the most lethal of the viral pathogens. The female genital tract is the primary site for heterosexual transmission of both C. trachomatis and HIV-1. Infection with C. trachomatis, and with a variety of other STIs, increases the risk for transmission of HIV-1, although the mechanisms for this finding remain unclear. We have used in vitro modeling to assess the mechanisms by which infection with genital C. trachomatis serovars might increase the transmission of HIV-1 across the female genital tract. C. trachomatis infection of an immortalized endocervical epithelial cell line (A2EN) increases the cell surface expression of the HIV-1 alternative primary receptor, galactosyl ceramide (GalCer), and of the HIV-1 co-receptors, CXCR4 and CCR5. C. trachomatis infection also increases the binding of HIV-1 to A2EN cells, and, subsequently, increases levels of virus in co-cultures of HIV-exposed A2EN and susceptible MT4-R5 T cells. Finally, in vivo endocervical cell sampling reveals a dramatic increase in the number of CD4+, CXCR4 and/or CCR5 positive T cell targets in the endocervix of C. trachomatis positive women when compared to those who are C. trachomatis negative. This combination of in vitro and in vivo results suggests several mechanisms for increased transmission of HIV-1 across the endocervices of C. trachomatis-infected women.     

Treatment of brain metastases from melanoma

Brain metastases from malignant melanoma have a poor prognosis, and treatment can be difficult because of rapid progression of the disease. To help define the treatment of this disease, we reviewed the published literature on brain metastases from melanoma. If a solitary metastasis is present, surgery might be beneficial, especially if systemic disease is absent. Stereotactic radiosurgery is a less invasive, attractive option for solitary or oligometastatic (up to 6) lesions. External beam whole-brain radiation therapy can produce responses and frequently palliates symptoms, but as the sole therapy, it is unlikely to eradicate brain metastases. Chemotherapy may be gaining a role with newer agents that penetrate the blood-brain barrier. Combined modality therapy appears to be the future direction of treatment of multiple metastases.