Glutamine and Other Amino Acid Losses During Continuous Venovenous Hemodiafiltration

Abstract: Serum amino grams and daily losses of glutamine (Gin) and other amino acids (AAs) into diafiltrate were measured during the first 5 days of continuous venovenous hemodiafiltration (CVVHDF) in 6 ICU patients with acute renal failure (ARF). Four patients had ARF as a part of multiple organ failure (MOF) of septic origin, and 2 patients had isolated ARF because of primary renal disease. During the study, all the patients received defined total parenteral nutrition (TPN). The mean daily AA losses into dialysate were relatively low (0.61 ± 0.1 g N ) and reached 4.5% of the daily AA substitution. Gln represented 32.7 ± 5.9% of the total AA losses (0.19 ± 0.04 g N ). Serum levels of Gin (p = 0.002) and of most other AAs were significantly lower in the patients than in the control subjects (AA analysis in 16 healthy volunteers). Phenylalanine (Phe) was the only AA that was increased significantly (p < 0.01) in the patients. The mean patient serum concentrations of Phe and tyrosine were significantly higher (p < 0.03) than the correspondent concentrations in dialysate, but the lysine concentration was higher in dialysate (p < 0.03). The serum and dialysate concentrations of other AAs did not differ. Gin in serum decreased significantly (p < 0.03) on the second day of CVVHDF but returned to the baseline levels subsequently. Serum concentrations of Phe increased on the second day of CVVHDF (p < 0.05). Serum concentrations of other AAs remained stable during the whole study. We conclude that Gin losses into dialysate during CVVHDF are relatively low, but CVVHDF itself may induce changes in Gin metabolism and distribution that are reflected by a decrease of serum Gin levels at the institution of this treatment. Therefore, the need for Gin supplementation in ICU patients is even greater in the first days of CVVHDF.     

Evaluation of Waiting Times and Sonographic Findings in Patients with First Trimester Vaginal Bleeding at the University Hospital of the West Indies. Can Emergency Department Ultrasound Make a Difference?

Background:

Pregnant female patients with vaginal bleeding in the first trimester are seen commonly in the Emergency Department (ED) at the University Hospital of the West Indies (UHWI), Kingston, Jamaica. The protocol for the management of these patients requires that they have a sonographic evaluation performed for the purpose of localizing the pregnancy where possible, to assist with determining the risk for an ectopic pregnancy. The ultrasound examinations are performed in the radiology department.

Objective:

This retrospective study was conducted to evaluate how long patients wait for a pelvic ultrasound. We also sought to establish how many patients had ultrasound findings that would have allowed safe discharge home.

Methods:

The records of 150 patients seen in the six-month period from January 1 to July 30, 2008 were examined. Data were extracted pertaining to age, time to see an emergency room doctor, time taken for ultrasound examination to be obtained from the radiology department and the ultrasound findings.

Result:

Fifty-four per cent presented to the Emergency Department with a complaint of vaginal bleeding and abdominal pain, 29% with bleeding only, 16% with abdominal pain only and one with syncope. One hundred and sixteen of the patients enrolled had an ultrasound performed at UHWI. The average waiting time for an ultrasound was 3.8 ± 2.5 hours. The majority (66/116) of the patients had an intrauterine pregnancy (IUP) demonstrated on ultrasound. Twenty-nine had no IUP, free fluid or adnexal mass. These 95 patients would likely have been discharged home. Ten patients had an adnexal mass with or without free fluid, and ten had free fluid only on ultrasound. One patient was found to have a definite ectopic pregnancy. These 21 patients would have been referred for evaluation by the obstetrician on call for further management.

Conclusion:

The majority of patients had sonographic findings that would have allowed safe and timely discharge from the Emergency Department had ultrasound been available at the point of care.     

Comparative study of seeding methods for three-dimensional polymeric scaffolds

Development of tissue-engineered devices may be enhanced by combining cells with porous absorbable polymeric scaffolds before implantation. The cells are seeded throughout the scaffolds and allowed to proliferate in vitro for a predetermined amount of time. The distribution of cells throughout the porous material is one critical component determining success or failure of the tissue-engineered device. This can influence both the successful integration of the device with the host tissue as well as the development of a vascularized network throughout the entire scaffold volume. This research sought to compare different seeding and proliferation methods to select an ideal method for a polyglycolide/aortic endothelial cell system. Two seeding environments, static and dynamic, and three proliferation environments, static, dynamic, and bioreactor, were analyzed, for a total of six possible methods. The six seeding and proliferation combinations were analyzed following a 1-week total culture time. It was determined that for this specific system, dynamic seeding followed by a dynamic proliferation phase is the least promising method and dynamic seeding followed by a bioreactor proliferation phase is the most promising.     

A homozygous SCN5A mutation in a severe,recessive type of cardiac conduction disease

Cardiac sodium channels are key players in the generation and propagation of action potentials in the human heart. Heterozygous mutations in the SCN5A gene have been found to be associated with long QT syndrome, Brugada syndrome, and sinus node dysfunction (SND). Recently, overlapping arrhythmia phenotypes have been reported as well. Here we describe a novel recessive SCN5A mutation in a family originating from the German minority in White Russia. Four affected children with a history of early cardiac arrhythmia encompassing SND, conduction disease, and severe ventricular arrhythmias, are homozygous carriers of a novel SCN5A missense mutation (p.I230T) in the channel protein. Interestingly, the heterozygous mutation carriers had neither significant ECG abnormalities nor a history of cardiac events. Heterologous expression of SCN5A(I230T) channels revealed normal protein transport but altered biophysical sodium channel properties. Voltage range of both activation and inactivation were shifted in a way that resulted in decreased sodium current and loss of channel function. In conclusion, we describe a rare clinical condition with a novel SCN5A mutation causing a new type of complex cardiac arrhythmia. Unlike most previously reported sodium channelopathies, this overlap syndrome displays recessive inheritance characteristics and does not seem to follow simple Mendelian rules.© 2010 Wiley‐Liss, Inc.