A STUDY OF THE INCREASED SERUM LEVEL OF IgG1 IN ‘LETHARGIC’ MICE COMBINED WITH A DEPRESSED THYMUS-DEPENDENT LYMPHOID SYSTEM

In a series of recent studies on ‘lethargic’ mice, a neurological mutation of the mouse, significant abnormalities were discovered in the thymus and its dependent regions in the lymph nodes and spleen. The present study was made as an approach toward finding the possible causes for these abnormalities. Serum IgG₁ levels were studied in ‘lethargic’ mutants at the age when severe deficiency of the thymus-dependent lymphoid system is known to occur in the animal. Using the radial immunodiffusion method, it was found that serum IgG₁ levels are always significantly higher in ‘lethargic’ mice than in their normal littermates. Possible causes of the higher IgG₁ in the serum of ‘lethargic’ mice are discussed. The authors note the similarities of other mouse mutations to that of the ‘lethargic’ mouse and propose the possibility that a common mechanism may account for immunologic deficiencies in several types of mutant mice.     

Barriers to neonatal care in developing countries: Parents' and providers' perceptions

Aim: Hospital care and advanced medical technologies for sick neonates are increasingly available, but not always readily accessible, in many countries. We characterised parents' and providers' perceptions of barriers to neonatal care in developing countries. Methods: We interviewed parents whose infant was hospitalised within the first month of life in Cambodia, Malaysia, Laos and Vietnam, asking about perceived barriers to obtaining newborn care. We also surveyed health-care providers about perceived barriers to providing care. Results: We interviewed 198 parents and 212 newborn care providers (physicians, nurses, midwives, paediatric and nursing trainees). Most families paid all costs of newborn care, which they reported as a hardship. Although newborn care is accessible, 39% reported that hospitals are too distant; almost 20% did not know where to obtain care. Parents cited lack of cleanliness (46%), poor availability of medications (42%) or services (36%), staff friendliness (42%), poor infant outcome (45%), poor communications with staff (44%) and costs of care (34%) as significant problems during prior newborn care. Providers cited lack of equipment (74%), lack of staff training (61%) and poor infrastructure (51%) as barriers to providing neonatal care. Providers identified distance to hospital, lack of transportation, care costs and low parental education as barriers for families. Conclusions: Improving cleanliness, staff friendliness and communication with parents may diminish some barriers to neonatal care in developing countries. Costs of newborn care, hospital infrastructure, distance to hospital, staffing shortages, limited staff training and limited access to medications pose more difficult barriers to remedy.     

Zanthoxylum avicennae extracts inhibit cell proliferation through protein phosphatase 2A activation in HA22T human hepatocellular carcinoma cells in vitro and in vivo

Hepatocellular carcinoma is a common type of cancer that is usually associated with poor prognosis. In this study, we examined the in vitro and in vivo mechanisms of the traditional Vietnamese herb Zanthoxylum avicennae on the inhibition of HA22T human hepatocellular carcinoma cell proliferation. HA22T cells were treated with different concentrations of Zanthoxylum avicennae extracts (YBBEs) and analyzed with the MTT assay, western blot analysis, flow cytometry, siRNA transfection assays and co-immunoprecipitation assay. Additionally, the HA22T-implanted xenograft nude mouse model was applied to confirm the cellular effects. YBBEs showed a strong inhibition of HA22T cell viability in a dose-dependent manner and significantly reduced cell proliferation-related proteins as well as induced cell cycle arrest in the G2/M phase. Protein phosphatase 2A (PP2A) siRNA or okadaic acid totally blocked YBBE-mediated cell proliferation inhibition. In addition, an HA22T-implanted nude mouse model further confirmed that YBBEs inhibit HA22T tumor cell growth and downregulate the survival and cell cycle regulating proteins, as well as activate the PP2A protein. Our findings indicate that the inhibition of HA22T cell proliferation by YBBEs is mediated through PP2A activation.     

Randomized pharmacokinetic and pharmacodynamic comparison of fluoroquinolones for tuberculous meningitis

Tuberculous meningitis (TBM) is the most lethal form of tuberculosis, and new treatments that improve outcomes are required. We randomly assigned adults with TBM to treatment with standard antituberculosis treatment alone or in combination with ciprofloxacin (750 mg/12 h), levofloxacin (500 mg/12 h), or gatifloxacin (400 mg/24 h) for the first 60 days of therapy. Fluoroquinolone concentrations were measured with plasma and cerebrospinal fluid (CSF) specimens taken at predetermined, randomly assigned times throughout treatment. We aimed to describe the pharmacokinetics of each fluoroquinolone during TBM treatment and evaluate the relationship between drug exposure and clinical response over 270 days of therapy (Controlled Trials number ISRCTN07062956). Sixty-one patients with TBM were randomly assigned to treatment with no fluoroquinolone (n = 15), ciprofloxacin (n = 16), levofloxacin (n = 15), or gatifloxacin (n = 15). Cerebrospinal fluid penetration, measured by the ratio of the plasma area under the concentration-time curve from 0 to 24 h (AUC(0-24)) to the cerebrospinal fluid AUC(0-24), was greater for levofloxacin (median, 0.74; range, 0.58 to 1.03) than for gatifloxacin (median, 0.48; range, 0.47 to 0.50) or ciprofloxacin (median, 0.26; range, 0.11 to 0.77). Univariable and multivariable analyses of fluoroquinolone exposure against a range of different treatment responses revealed worse outcomes among patients with lower and higher plasma and CSF exposures than for patients with intermediate exposures (a U-shaped exposure-response). TBM patients most likely to benefit from fluoroquinolone therapy were identified, along with exposure-response relationships associated with improved outcomes. Fluoroquinolones add antituberculosis activity to the standard treatment regimen, but to improve outcomes of TBM, they must be started early, before the onset of coma.     

Laparoscopic live donor right nephrectomy: a new technique to maximize the length of the renal vein using a modified Endo GIA stapler

OBJECTIVES: To report the utilization of a modified Endo GIA vascular stapler to obtain the full length of the renal vein during transperitoneal laparoscopic live donor right nephrectomy. METHODS: We used a modified Endo GIA stapler, in which the triple staggered rows of staples were removed from the kidney donor side to obtain the full length of the right renal vein. This technique has currently been used in nine consecutive transperitoneal laparoscopic right donor nephrectomies. RESULTS: With this technique, the entire right renal vein length was harvested in all cases, without vascular complications. Mean renal warm ischemia time from clamping of the renal vessels to cold perfusion was 135s, and mean receptor postoperative glomerular filtration rate after 30 d was 67.3 ml/min. There were no graft losses. CONCLUSIONS: A novel technique for laparoscopic live donor right nephrectomy is described. It allows harvesting the full length of the right renal vein in a safe and feasible way without compromising warm ischemia time.     

Multifunctional Coupling Agents: 3. Segmented Block Copolymers Based on Carboxy‐Terminated Poly(propylene oxide) and Amino‐Terminated Polyamide 12

Summary: Segmented block copolymers were synthesized in melt by conversion of carboxy‐terminated poly(propylene oxide) and amino‐terminated PA12 with a selectively reacting bifunctional coupling agent bearing one oxazoline and one oxazinone group. The reaction was performed either in one or two steps. In the latter, it could be shown that the sequence of mixing significantly influenced the course of reaction. The structure of the linking group formed during the reaction was verified by ¹H NMR spectroscopy using model compounds. DSC and TEM investigations evidenced that the block copolymers are phase separated. Domains in a size of several nanometers are found. Owing to the two phase structure, the block copolymers show ductile behavior with the tendency to elastomeric behavior. Tensile properties of the block copolymers increase with the content of PA12. Elongations at break were measured with values up to 500%.

TEM micrograph of block copolymer 6b .     

Effect of Transition Elements on the Thermal Stability of Glassy Alloys 82Al–16Fe–2TM (TM: Ti,Ni, Cu) Prepared by Mechanical Alloying

In the present study, the thermal stability and crystallization behavior of mechanical alloyed metallic glassy Al₈₂Fe₁₆Ti₂, Al₈₂Fe₁₆Ni₂, and Al₈₂Fe₁₆Cu₂ were investigated. The microstructure of the milled powders was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed remarkable distinction in thermal stability of the alloys by varying only two atomic percentages of transition elements. Among them, Al₈₂Fe₁₆Ti₂ alloy shows the highest thermal stability compared to the others. In the crystallization process, exothermal peaks corresponding to precipitation of fcc-Al and intermetallic phases from amorphous matrix were observed.     

Prevalence and Visual Risk Factors for Falls in Bilateral Cataract Patients in Ho Chi Minh City,Vietnam

Abstract

Purpose: To determine the prevalence of falls in the 12 months prior to cataract surgery and examine the associations between visual and other risk factors and falls among older bilateral cataract patients in Vietnam.

Methods: Data collected from 413 patients in the week before scheduled cataract surgery included a questionnaire and three objective visual tests.

Results: The outcome of interest was self-reported falls in the previous 12 months. A total of 13% (n?=?53) of bilateral cataract patients reported 60 falls within the previous 12 months. After adjusting for age, sex, race, employment status, comorbidities, medication usage, refractive management, living status and the three objective visual tests in the worse eye, women (odds ratio, OR, 4.64, 95% confidence interval, CI, 1.85–11.66), and those who lived alone (OR 4.51, 95% CI 1.44–14.14) were at increased risk of a fall. Those who reported a comorbidity were at decreased risk of a fall (OR 0.43, 95% CI 0.19–0.95). Contrast sensitivity (OR 0.31, 95% CI 0.10–0.95) was the only significant visual test associated with a fall. These results were similar for the better eye, except the presence of a comorbidity was not significant (OR 0.45, 95% CI 0.20–1.02). Again, contrast sensitivity was the only significant visual factor associated with a fall (OR 0.15, 95% CI 0.04–0.53).

Conclusion: Bilateral cataract patients in Vietnam are potentially at high risk of falls and in need of falls prevention interventions. It may also be important for ophthalmologists and health professionals to consider contrast sensitivity measures when prioritizing cataract patients for surgery and assessing their risk of falls.