A Reciprocating, Single-Needle Hemodialyzer with Bidirectional Flow of Sorbent Suspension

Previous theoretical analysis has indicated that adequate mass transfer is possible in a dialyzer with reciprocating membrane motion provided that the dialysate concentration of uremic substances is kept low. Earlier models have utilized a collection of sorbents (charcoal, urease, and a cation exchanger) constrained next to the dialyzer membranes. We have designed a new dialyzer with a sorbent suspension having free access from a reservoir to the spaces between membrane packages. At a treatment rate of 150 ml/min/m², the in vitro creatinine clearance is 75 ml/min/m², which agrees within experimental accuracy with the theoretical prediction. The creatinine clearance, flow resistance, and compliance of the dialyzer are constant during four to six hours of testing. In vivo tests have been performed during urea and creatinine infusion in a normal dog and in a dog with 3/4 nephrectomy. The in vivo creatinine clearance agrees within 10% with the in vitro clearance. Sodium, potassium, calcium, and bicarbonate fluxes are acceptable for patients in renal failure. The new design allows a higher capacity for urea and creatinine, since larger amounts of sorbent may be used.     

Lumbar disk herniation: MR imaging assessment of natural history in patients treated without surgery.

The aim of this study was to evaluate the evolution of lumbar disk herniation in patients treated without surgery. Sixty-nine patients with a lumbar disk herniation proved at magnetic resonance (MR) imaging underwent a follow-up MR imaging study. The disk herniations evaluated during both MR imaging examinations were measured and classified into four categories according to the change in size that occurred. The patients were also divided into three clinical classes on the basis of the clinical outcome. Sixty-three percent of the patients showed a reduction of disk herniation of more than 30% (48% had a reduction of more than 70%), while only 8% demonstrated worsening of the clinical picture. These findings suggest that lumbar disk herniation may be primarily a medical (nonsurgical) disease and that MR imaging could play an important role in management of and research into the disorder.     

Rifabutin-associated uveitis in an immunosuppressed pediatric patient without acquired immunodeficiency syndrome

Purpose: To describe a case of bilateral, symptomatic rifabutin-associated uveitis with hypopyon and vitreal opacities in an immunosuppressed pediatric patient without acquired immunodeficiency syndrome (AIDS).Method: Case report. An 8-year-old boy presented with bilateral uveitis 24 months after a bilateral lung transplant.Results: Our patient, whose medications included rifabutin, clarithromycin, and immunosuppressive agents, responded to discontinuation of the rifabutin and initiation of intensive topical corticosteroid therapy with complete resolution of the uveitis.Conclusion: Rifabutin-associated uveitis may occur in a non-AIDS pediatric patient.     

Monitoring population health for Healthy People 2020: evaluation of the NIH PROMIS® Global Health, CDC Healthy Days, and satisfaction with life instruments

Purpose

Healthy People 2020 identified health-related quality of life and well-being (WB) as indicators of population health for the next decade. This study examined the measurement properties of the NIH PROMIS^® Global Health Scale, the CDC Healthy Days items, and associations with the Satisfaction with Life Scale.

Methods

A total of 4,184 adults completed the Porter Novelli’s HealthStyles mailed survey. Physical and mental health (9 items from PROMIS Global Scale and 3 items from CDC Healthy days measure), and 4 WB factor items were tested for measurement equivalence using multiple-group confirmatory factor analysis.

Results

The CDC items accounted for similar variance as the PROMIS items on physical and mental health factors; both factors were moderately correlated with WB. Measurement invariance was supported across gender and age; the magnitude of some factor loadings differed between those with and without a chronic medical condition.

Conclusions

The PROMIS, CDC, and WB items all performed well. The PROMIS items captured a broad range of functioning across the entire continuum of physical and mental health, while the CDC items appear appropriate for assessing burden of disease for chronic conditions and are brief and easily interpretable. All three measures under study appear to be appropriate measures for monitoring several aspects of the Healthy People 2020 goals and objectives.     

Approaches to addressing occupational and environmental health needs in Mexico.

The University of California, Los Angeles, has somewhat shifted the focus of its Fogarty program, taking a four-pronged approach: conducting high-level collaborative scientific research with Mexican faculty and trainees at the most advanced institutions in the country; providing training and collaborative research opportunities to faculty/students at other institutions in Mexico (primarily through training faculty who do not hold doctoral degrees); providing environmental and occupational health training to the professional community throughout Mexico; and developing short courses on special topics that provide means for greater research collaboration and skill building. The program is also working with existing institutions to develop academic programs that will enlarge the environmental and occupational health infrastructures in Mexico and Latin America.     

Obesity and Circulating Levels of Vitamin D before and after Weight Loss Induced by a Very Low-Calorie Ketogenic Diet

Background: Vitamin D plays a pivotal role in calcium and phosphorus metabolism, also influencing bone tissue. Several studies have reported that vitamin D blood levels were significantly lower in people with obesity, probably due to its uptake by the adipose tissue. Clinical studies that investigated the changes of circulating levels of vitamin D following weight loss reported controversial data. A very low-calorie ketogenic diet is acknowledged as a reliable treatment to achieve a rapid weight loss. Therefore, we investigated the effect of weight loss, consequent to a very low-calorie ketogenic diet, on vitamin D blood concentrations. Methods: A cohort of 31 people with obesity underwent a very low-calorie ketogenic diet for 10–12 weeks. The serum concentrations of vitamin D, parathormone, calcium and phosphorous were measured before and after weight loss; they were compared to a control group of 20 non-obese, non-diabetic, age- and gender-matched persons. Results: Patients with obesity had a higher habitual intake of vitamin D than the control group (p < 0.05). However, the vitamin D blood levels of the obese group were significantly lower than those of the control group (p < 0.005) and they increased after weight loss (p < 0.001). At baseline, vitamin D blood concentrations of the persons with obesity were significantly correlated with both fat mass–kg (r = −0.40; p < 0.05) and body mass index (r = −0.47; p < 0.01). Following very low-calorie ketogenic diet, the change in vitamin D serum concentrations was correlated only with the change in fat mass–kg (r = −0.43; p < 0.01). Conclusion: This study confirmed that patients with obesity have lower vitamin D levels that normalize after significant weight loss, supporting the hypothesis that vitamin D is stored in the adipose tissue and released following weight loss.     

Interventional radiology in the spleen

Despite the widespread use of interventional radiologic techniques, there has been reluctance to apply these to the spleen. Concern for bleeding and difficulty in negotiating around the colon and pleura have limited its use. The authors report their experience with interventional radiology of the spleen in 35 cases, including percutaneous biopsy (n = 5), diagnostic and therapeutic fluid aspiration (n = 14), and catheter drainage of abscesses (n = 9), hematomas (n = 2), intrasplenic pancreatic pseudocysts (n = 2), and necrotic tumor (n = 1). Transsplenic fluid aspiration and biopsy of the pancreas and adrenal gland were performed as well (n = 2). All procedures were performed under computed tomographic or ultrasound guidance. Biopsies were performed with 22- or 20-gauge needles only; no complications were encountered. Diagnoses included primary and secondary malignancies and an infectious process. Drainages were successful in 11 of 14 patients; pleural effusions occurred in two cases, but neither required specific therapy. Interventional radiologic procedures in the spleen are feasible, and the authors discuss methods to promote their safe application.