Lung dendritic cells are primed by inhaled particulate antigens, and retain MHC class II/antigenic peptide complexes in hilar lymph nodes for a prolonged period of time

Intratracheal (IT) administration of heat-killed Listeria monocytogenes (HKL) results in an influx of macrophage and dendritic cell (DC) precursors into the lung interstitium. Low-density, FcR+, interstitial lung cells isolated from rats instilled 24 hr before with HKL or vehicle alone, were > 90% Mar1+. After culturing with granulocyte-macrophage colony-stimulating factor (GM-CSF) for 3 days, up to 24% of the loosely adherent cells were DC that stimulated allogeneic T-cell proliferation in an mixed lymphocyte reaction (MLR) assay. After only an overnight incubation with GM-CSF, however, the capacity of interstitial Mar1+ cells to stimulate HKL immune T-cell proliferation without exogenous antigen was low. By contrast, when DC were isolated as major histocompatibility complex (MHC) class II+ cells from rat lungs at 1, 3, 7 and 14 days after HKL instillation and cultured overnight with GM-CSF, their antigen presentation capacity without added exogenous antigen was robust, but declined over the 2-week period. Interestingly, hilar lymph node DC maintained their HKL antigen-presenting capacity for up to 2 weeks after instillation of HKL. Following IT administration of PKH-26 labelled HKL, fluorescent or immunolabelled organisms were detected in OX62+ DC in airway epithelium, lung interstitium and hilar lymph nodes in situ and in MHC class II+ DC isolated from these sites. We conclude that newly immigrated Mar1+ lung DC precursors, while efficient in endocytosing particulate antigens, are incapable of eliciting a significant proliferative response from HKL-sensitized T cells. By contrast, MHC class II+ DC isolated from lungs and incubated overnight with GM-CSF induce vigorous antigen-specific T-cell proliferation. Antigen-loaded lung DC in hilar lymph nodes maintain their antigen presentation capacity for up to 2 weeks.     

Hepatectomy in intrahepatic lithiasis

STUDY AIM: The aim of this study was to report the immediate results of a series of 65 hepatic resections for hepatolithiasis performed in Vietnam. PATIENTS AND METHOD: From 1986 to 1998, 44 men and 21 women (mean age: 40 years) underwent hepatic resection for hepatolithiasis. Fourty patients had previously undergone one or several operations for hepatolithiasis. The procedure was performed on emergency in 25 patients. Indications for hepatic resection were: angiocholitis and liver abscess in 22 cases, stones closely inserted in the biliary duct in 20 cases, hemobilia in 12 cases, stones located above a biliary stricture in 8 cases and stones associated with a postoperative biliary fistula in 3 cases. Liver resections (minor in 61 patients, including 55 left lobectomies, and major in 4 patients) were performed through transhepatic approach according to the Ton That Tung technique and followed by an external biliary drainage with a Kehr tube. RESULTS: There were 6 postoperative deaths (9%), 3 due to septic shock, 2 to cachexia, and 1 to liver failure. The 15 patients with complications recovered with conservative therapy. Bile infection was present in 93%, mostly with Escherichia coli and Enterobacter. Pigmented stones were usually found. CONCLUSION: Vietnam is a country with high incidence of hepatolithlasis. Hepatic resection is an adequate treatment for localized intrahepatic bile duct stones when the involved segment including biliary strictures and calculi can be completely removed. The procedure may be performed on emergency for liver abscess, or hemobilia.     

Surgery of labio-maxillo-palatal clefts during humanitarian mission in the Philippines

After describing the Philippines and the Comité de Soutien Enfance Philippines, a humanitarian association with a three-fold objective: to build, to educate and to treat, the authors present the organization and practical conduct of their missions abroad which have enabled them to treat almost 400 patients with cleft lip and palate between the ages of 3 months and 46 years.     

Highly sensitive and selective colorimetric detection of Pb(ii) ions using Michelia tonkinensis seed extract capped gold nanoparticles

In this study, gold nanoparticles (AuNPs) were synthesized via a green and environmentally-friendly approach and applied as a colorimetric probe for detecting Pb²⁺ ions in aqueous solution. Instead of toxic chemicals, Michelia tonkinensis (MT) seed extract was used for reducing Au³⁺ and stabilizing the formed AuNPs. The synthesis conditions, including temperature, reaction time, and Au³⁺ ion concentration, were optimized at 90 °C, 40 min, and 1.25 mM, respectively. The physicochemical properties of the produced MT-AuNPs were assessed by means of transmission electron microscopy, X-ray diffraction, field emission scanning electron microscopy, dynamic light scattering, and Fourier-transform infrared spectroscopy. The characterization results revealed that the MT-AuNPs exhibited a spherical shape with a size of about 15 nm capped by an organic layer. The colorimetric assay based on MT-AuNPs showed excellent sensitivity and selectivity toward Pb²⁺ ions with the limit of detection value of 0.03 μM and the limit of quantification of 0.09 μM in the linear range of 50–500 μM. The recoveries of inter-day and intra-day tests were 97.84–102.08% and 98.78–102.34%, respectively. The MT-AuNPs probe also demonstrated good and reproducible recoveries (98.71–101.01%) in analyzing Pb²⁺ in drinking water samples, indicating satisfactory practicability and operability of the proposed method.

Michelia tonkinensis seed extract capped AuNPs exhibit great potential in analyzing Pb²⁺ ions in aqueous solution.     

Structure and hemolytic activity relationships of triterpenoid saponins and sapogenins

We evaluated the hemolytic activity of 41 commercially available triterpenoid saponins and sapogenins derived from three types of structural skeletons. Structure–activity relationships were established by comparing the structural characteristics of both the aglycone and sugar moieties among the tested compounds. The majority of oleanane-type sapogenins had stronger hemolytic effects than those of the ursane and dammarane types. The presence of polar regions on sapogenins, such as a carboxyl (COOH) at position 28, an α-hydroxyl (α-OH) at position 16, and/or a β-hydroxyl (β-OH) at position 2, significantly enhanced hemolysis. Meanwhile, the introduction of an α-OH at position 2 or a methyl hydroxyl (CH₂OH) at positions 23 or 24 was closely associated with reduced activity. Our findings suggest that not only the complexity of sugar moieties but also the types and stereochemical configurations of functional groups at different positions, as well as the skeleton types, are important structural features affecting hemolytic potential. Our results provide a baseline in terms of the toxicity of saponins and sapogenins to erythrocytes, which holds promise for drug development.     

Efficacy of a Church-Based,Culturally Tailored Program to Promote Completion of Advance Directives Among Asian Americans

Having an Advance Directive (AD) can help to guide medical decision-making. Asian Americans (AA) are less likely than White Americans to complete an AD. This pilot study investigated the feasibility and efficacy of a church-based intervention to increase knowledge and behavior change related to AD among Chinese and Vietnamese Americans. This study utilized a single group pre- and post-intervention design with 174 participants from 4 churches. Domain assessed: demographics; AD-related knowledge, beliefs, attitudes, and intentions; AD completion; and conversations with a healthcare proxy. Data were analyzed using Chi square and multiple logistic regression techniques. We observed significant increases in participants’ AD-related knowledge, intentions, and a gain in supportive beliefs and attitudes about AD, resulting in 71.8 % AD completion, and 25.0 % having had a proxy conversation. Providing culturally-tailored intervention and step-by-step guidance can help to achieve significant changes in AD related knowledge and behavior in AA church goers.