Generation of Ag Nanoparticles by PAMAM Dendrimers and their Size Dependence on the Aggregation Behavior of Dendrimers

Stable silver nanoparticles were generated in aqueous medium by amine, hydroxy and carboxylate terminated poly(amidoamine) (PAMAM) dendrimers in the absence of conventional reducing agents and light irradiation. Mechanistic studies suggest that, in spite of their lower pK_a values, tertiary amines present in the dendritic structures act as the reducing agent. Dynamic light scattering and electron microscopic studies reveal that PAMAM dendrimers aggregate in presence of silver ions and the aggregation propensity plays a pivotal role in altering the size and shape of the nanoparticles generated in the dendritic milieu. The formation of metal nanoparticles with uniform size and shape by amine terminated PAMAM dendrimer is attributed to the unique aggregation propensity of amine terminated PAMAM.

     

Secondary chondrosarcoma in an enchondroma in a proximal phalanx of toe. A diagnostic problem. A case report

The authors present a case of secondary chondrosarcomatous transformation in enchondroma in toe. The authors have discussed the available literature to throw light on differentiation of benign and malignant form.     

Diclofenac-induced biochemical and histopathological changes in white leghorn birds (Gallus domesticus)

Objective:

Objective: To evaluate diclofenac-induced biochemical and histopathological changes in White Leghorn birds.

Materials and Methods:

Six-week-old birds were equally divided into three groups of six birds each. Group I served as control and received vehicle orally. The birds of Group II and III were orally administered with a single low (2 mg/kg) and high dose (20 mg/kg) of diclofenac sodium, respectively, and were observed for 7 days. The acute toxicity was assessed by observing the clinical signs and symptoms, mortality, alterations in blood biochemistry, and necropsy findings.

Results:

The birds of Group II showed only mild symptoms of diarrhea. In Group III, 50% of birds died in between 24 and 36 h post-treatment showing the symptoms of segregatory behavior, lethargy, terminal anorexia, and severe bloody diarrhea. The birds of Group II and the surviving birds of Group III showed a significantly (P<0.05) increased plasma uric acid, creatinine and plasma glutamic pyruvic transaminase (PGPT), and decreased total protein and albumin at 12 and 24 h post-treatment which returned to the normal levels at 36 h post-treatment. The dead birds of the high-dose group also showed similar pattern of biochemical changes at 12 and 24 h post-treatment and revealed extensive visceral gout with characteristic histopathological lesions in liver, kidney, heart, spleen, and intestine on post-mortem.

Conclusion:

The results indicate that diclofenac sodium has hepatotoxic, nephrotoxic, and visceral gout inducing potentials in White Leghorn birds, especially at higher dose.     

Circulating endothelial cells, arterial stiffness, and cardiovascular risk stratification in hypertension

BACKGROUND: Given the growing burden of cardiovascular disease, there is increasing interest in strategies to help predict future cardiovascular risk. Aims: To investigate the relationship between endothelial damage/dysfunction, arterial stiffness, and their association with predicted risk of future cardiovascular death among patients with hypertension. METHODS: We studied three patient groups 35 to 74 years old: healthy control subjects (n=63), subjects with high-risk hypertension (HHT) [n=65], and patients with treated, previously diagnosed, malignant-phase hypertension (MHT) [n=43]. We measured comparative indexes of arterial stiffness (stiffness index [SI] using digital volume photoplethysmography), endothelial damage/dysfunction (venous circulating endothelial cells [CECs], immunobead technique), and 5-year predictive risk of future cardiovascular death (Pocock scoring system). RESULTS: CEC counts, SI, and 5-year prediction of cardiovascular death were significantly higher in both hypertension groups (HHT and MHT), compared with healthy control subjects. CEC counts were significantly higher in the MHT group (p<0.05). There was a significant correlation between CECs and SI in the HHT group (r=0.61; p<0.0001) and the MHT group (r=0.59, p<0.0001) and between CEC, SI, and predicted 5-year risk of cardiovascular death in the two hypertension groups. On multiple linear regression analysis, arterial SI and CECs remained as significant predictors of the calculated 5-year risk of cardiovascular death (R2=0.37; p<0.0001). CONCLUSION: There is a consistent association between CECs, arterial stiffness, and the predictive risk of cardiovascular death among a group of patients with HHT or previously treated MHT. Registration number 05/Q2709/1.     

Two novel AIRE mutations in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) among Indians

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare recessive disorder resulting from mutations in the autoimmune regulator ( AIRE ) gene. There is no information on AIRE mutations in Indians. In a cross-sectional study, nine patients (eight families), from four referral hospitals in India, were studied for AIRE mutations by direct sequencing. We screened for new mutations in 150 controls by allele-specific PCR. The patients had 1–7 known components of APECED. Three patients had unusual manifestations: presentation with type 1 diabetes; chronic sinusitis and otitis media; and facial dysmorphism. All patients carried homozygous, probably recessive, AIRE mutations. Two unrelated patients from a small in-bred community (Vanika Vaisya) in south India carried an unreported missense mutation, p.V80G, in the N-terminal caspase recruitment domain. Another unique mutation, p.C302X, resulting in a truncated protein with deletion of both zinc-finger domains, was detected in a patient from Gujarat. Neither mutation was detected in controls. Other mutations, previously described in Caucasians, were: 13 base pair deletion (p.C322fsX372) in 4 (38%), and Finn-major (p.R257X) and p.R139X (Sardinian) mutation in one subject each. In conclusion, in this first series of APECED in Indians, we detected AIRE mutations previously reported in Caucasians, as well as unique mutations. Of these, p.V80G is possibly an ancestral mutation in an in-bred community.     

Strain-specific requirement for eosinophils in the recruitment of T cells to the lung during the development of allergic asthma

Eosinophils have been implicated as playing a major role in allergic airway responses. However, the importance of these cells to the development of this disease has remained ambiguous despite many studies, partly because of lack of appropriate model systems. In this study, using transgenic murine models, we more clearly delineate a role for eosinophils in asthma. We report that, in contrast to results obtained on a BALB/c background, eosinophil-deficient C57BL/6 Delta dblGATA mice (eosinophil-null mice via the Delta DblGATA1 mutation) have reduced airway hyperresponsiveness, and cytokine production of interleukin (IL)-4, -5, and -13 in ovalbumin-induced allergic airway inflammation. This was caused by reduced T cell recruitment into the lung, as these mouse lungs had reduced expression of CCL7/MCP-3, CC11/eotaxin-1, and CCL24/eotaxin-2. Transferring eosinophils into these eosinophil-deficient mice and, more importantly, delivery of CCL11/eotaxin-1 into the lung during the development of this disease rescued lung T cell infiltration and airway inflammation when delivered together with allergen. These studies indicate that on the C57BL/6 background, eosinophils are integral to the development of airway allergic responses by modulating chemokine and/or cytokine production in the lung, leading to T cell recruitment.     

Signs and symptoms predictive of respiratory failure in patients with foodborne botulism in Thailand

We conducted a clinical study of 137 patients with home-canned bamboo shoot botulism at Nan Hospital, northern Thailand. The median age of the patients was 44 years (range = 14-74 years) and 36.2% were male. The median incubation period was 2 days (range = 1-8 days). Forty-three patients (31.4%) developed respiratory failure, but there were no deaths. Patients who did not have either nausea or vomiting and did not have urinary retention that required Foley catheterization was less likely to develop respiratory failure. This clinical predictor rule had a sensitivity of 75.5% and a specificity of 90.7%. The clinical syndrome most predictive of respiratory failure was nausea or vomiting and any cranial neuropathy with urinary retention or difficulty swallowing. This clinical syndrome had a sensitivity of 69.8% and a specificity of 93.6%. These clinical characteristics could help triage large numbers of patient in the event of a future outbreak.