Monitoring small molecule diffusion into hydrogels at various temperatures by fluorescence technique

Steady state fluorescence technique was used to study small molecule diffusion into polyacrylamide (PAAm) gels at various temperatures. Pyranine (P(y)), dissolved in water was introduced as a probe and fluorescence emission (I(p)) from P(y) was monitored during diffusion. Scattered light intensities, I(sc) from PAAm gel was also monitored to observe structural variations during diffusion process. Increase in I(p) intensity was attributed to P(y) diffusion into PAAm gel. On the other hand decrease in I(sc) intensity was interpreted as the variation of the spatial heterogeneities in the system. Li-Tanaka and Fickian models were used to quantify the swelling and diffusion experiments and diffusion coefficients were produced in both cases. Related activation energies were also calculated from the corresponding physical processes.     

PET imaging of cortical <Superscript>11</Superscript>C-nicotine binding correlates with the cognitive function of attention in Alzheimer’s disease

Rationale Patients suffering from Alzheimer’s disease (AD) experience a marked reduction in cortical nicotinic acetylcholine receptors (nAChRs). In particular, selective loss of the α₄β₂ nAChR subtype was observed in postmortem AD brain tissue. The α₄ and α₇ nAChR subunits were suggested to play an important role in cognitive function. Positron emission tomography (PET) has so far been used to visualize neuronal nAChRs in vivo by ¹¹C-nicotine binding.Objectives To investigate the relationship between measures of cognitive function and in vivo ¹¹C-nicotine binding in mild AD brain as assessed by PET.Materials and methods Twenty-seven patients with mild AD were recruited in this study. A dual tracer model with administration of ¹⁵O-water for regional cerebral blood flow and (S)(−)¹¹C-nicotine was used to assess nicotine binding sites in the brain by PET. Cognitive function was assessed using neuropsychological tests of global cognition, episodic memory, attention, and visuospatial ability.Results Mean cortical ¹¹C-nicotine binding significantly correlated with the results of attention tests [Digit Symbol test (r=−0.44 and p=0.02) and Trail Making Test A (TMT-A) (r=0.42 and p=0.03)]. No significant correlation was observed between ¹¹C-nicotine binding and the results of tests of episodic memory or visuospatial ability. Regional analysis showed that ¹¹C-nicotine binding in the frontal and parietal cortex, which are the main areas for attention, correlated significantly with the Digit Symbol test and TMT-A results.Conclusion Cortical nicotinic receptors in vivo in mild AD patients are robustly associated with the cognitive function of attention.     

From conflict to collaboration, local political climate accelerates ITREOH's regionalization in South Asia

As Pakistan becomes industrialized, the development of human resources is essential to addressing emerging health problems. The Fogarty International Center (FIC)-funded University of Alabama at Birmingham (UAB)-Aga Khan University (AKU) ITREOH initiative has been instrumental in filling the gaps in environmental and occupational health (EOH) training and research. Because of travel impediments to Pakistan, a regional short-term training program was implemented in Nepal and Sri Lanka. Workshop participants were from Pakistan, Nepal, Sri Lanka, India, and Bangladesh. The training programs enhanced north-to-south and south-to-south collaboration in research and training in South Asia. A major impact is the development of a certificate program in EOH at AKU. Research initiatives of regional and/or global concern are also under way in the other participating countries. The combination of face-to-face training with Web-based interaction for follow-up was optimal for short-term training.     

Antioxidant properties of flavone-6(4′)-carboxaldehyde oxime ether derivatives

The in vitro antioxidant properties of some flavone-6(4)-carboxaldehyde oxime ether derivatives (Ia-f, IIa-f) were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP) levels by measuring the formation of 2-thiobarbituric acid reactive substances. The free radical scavenging properties of the compounds were also examined in vitro by determining their capacity to scavenge superoxide anions and interact with the stable free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH). The most active compounds, IIb (Flavone-4'-carboxaldehyde-O-ethyl oxime) and Id (Flavone-6-carboxaldehyde-O-[2-(1-pyrolidino) ethyl] oxime), caused 98 and 79% inhibition of superoxide anion production and DPPH stable free radical at 10(-3) M, respectively.     

Exponential health utility

In a recent contribution Happich and Muhlbacher proposed an axiom of constant absolute trade-off of life-years for health states, and studied the family of QALY models satisfying this axiom under expected utility and mutual utility independence between life-years and health states. Here we provide a complete characterization of the family of QALY models satisfying these conditions. This family should not be mistaken for the family of multiplicative exponential QALY models; in particular, it violates the zero condition.     

Steroid receptor status,proliferation and metallothionein expression in primary invasive ductal breast cancers

The most important immunocytochemical prognostic and predictive factors in cases of breast cancer include estrogen receptor alpha (ER) and progesterone receptor (PgR). The present study aimed at examining the relationship between the manifestation intensity of proliferation markers (Ki-67 and nucleolar organizer regions--AgNORs) on one hand, and expression of ER and PgR on the other in a uniform group of invasive ductal breast cancers of G2 grade. Moreover, the study aimed at examining the relationship between the above mentioned markers and expression of metallothionein (MT). The studies were performed on samples of invasive ductal breast cancers of G2 grade, originating from 60 females. In paraffin sections originating from the studied cases immunocytochemical reactions were performed using monoclonal antibodies to ER, PgR, Ki-67 and MT, and silver staining was conducted to localize AgNORs. The obtained results were subjected to statistical analysis using Statistica software. Results indicate that manifestation of AgNORs does not correlate with any of the studied antigens (ER, PgR, Ki-67, MT) (p>0.05). Moreover, no relationship could be demonstrated between the intensity of MT expression and proliferation markers or steroid receptor status (p>0.05). A negative correlation was shown between the expression of ER and Ki-67 (p=0.0009). The most intense proliferative activity was demonstrated in cases of breast cancer showing PgR expression but no ER expression (p=0.015), while the lowest proliferative activity was detected in breast cancers with expression of both ER and PgR (p<0.05).     

MRI demonstration of cervical spondylodiscitis and distal full-length bilateral paraspinal cold abscesses successfully treated by drug regimen only

Objective Cold abscesses, although common in spinal tuberculosis, are usually localized to the level of infection, follow tissue planes, and may extend into the spinal canal at any level. They may cause symptoms resulting from neurovascular compression, hemorrhage, and direct mass effect.Design and patients We present an unusual case of cervical tuberculous spondylodiscitis in a 25-year old man with a cold abscesses involving the retropharyngeal, mediastinal, and retroperitoneal areas bilaterally. The abscess tracked from the neck to the psoas muscles bilaterally. Following the diagnosis the patient received 9 months of antituberculous therapy.Results MRI showed resolution on medical treatment alone.Conclusions Even in the presence of massive paravertebral cold abscesses medical treatment alone may well suffice for this common worldwide disorder. MRI is ideal for monitoring regression of massive abscesses in deep anatomical locations.     

The longest use of liposomal amphotericin B and 5-fluorocytosine in neonatal renal candidiasis

Bilateral fungal obstruction of the renal collecting system is rare in infancy. Treatment options include medical or surgical procedures. Reports of successful medical treatment with liposomal amphotericin B have been published but the duration of treatment is controversial. We report a 3-week-old preterm baby with myelomeningocele who had experienced acute renal failure related to bilateral renal fungus balls, which improved with percutaneous nephrostomy and 12 weeks of liposomal amphotericin B intravenously combined with 5-fluorocytosine orally for 9 weeks.     

An unusual cause of acute renal failure: renal lymphoma

Renal involvement is a common finding in non-Hodgkins lymphoma (NHL). Acute renal failure at initial presentation due to lymphomatous infiltration of the kidneys has been described infrequently. We report a 17-year-old male who presented with acute renal failure due to massive lymphomatous infiltration of the kidneys, which necessitated hemodialysis. The diagnosis of B-cell NHL was established by tru-cut biopsy of the kidneys and the patient had an excellent response to high-dose chemotherapy with no major complication. The presence of extrarenal involvement in the testes and the retroperitoneal lymph nodes made the diagnosis of primary renal lymphoma debatable. However, considering the delay in diagnosis and the high proliferative rate of B-cell NHL, we might postulate that the disease had originated primarily in the kidneys. We recommend that in NHL cases with severe renal involvement, full-dose chemotherapy should be instituted with meticulous clinical and laboratory follow-up in order to improve clinical and renal failure status rapidly and to avoid further dissemination of NHL.