Solid-State Stability of Spray-Dried Insulin Powder for Inhalation: Chemical Kinetics and Structural Relaxation Modeling of Exubera Above and Below the Glass Transition Temperature

The effect of temperature on the chemical stability of an amorphous spray-dried insulin powder formulation (Exubera)® was evaluated in the solid state at constant moisture content. The chemical stability of the powder was assessed using reversed-phase high-performance liquid chromatography (RP-HPLC) and high-performance-size exclusion chromatography (HP-SEC). The major degradants in spray-dried insulin produced during heat stressing were identified as A21-desamidoinsulin (A21) and high molecular weight protein (HMWP). As expected, the rates of formation of A21 and HMWP were observed to increase with temperature. A stretched-time kinetic model (degradation rate is proportional to the square root of time) was applied to the degradant profiles above and below the glass transition temperature (T_g) and apparent reaction rate constants were determined. Below T_g, isothermal enthalpy of relaxation measurements were used to assess the effect of temperature on molecular mobility. The formation of A21 and HMWP was found to follow an Arrhenius temperature dependence above and below the T_g. Comparison of reaction rate constants to those estimated from structural relaxation experiments suggests that the reaction pathways to form A21 and HMWP below the T_g may be coupled with the molecular motions involved in structural relaxation. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3698–3710, 2010     

A 22-week, multicenter, randomized, double-blind controlled trial of Crocus sativus in the treatment of mild-to-moderate Alzheimer’s disease

Rationale

There is increasing evidence to suggest the possible efficacy of Crocus sativus (saffron) in the management of Alzheimer’s disease (AD).

Objective

The purpose of the present investigation was to assess the efficacy of C. sativus in the treatment of patients with mild-to-moderate AD.

Methods

Fifty-four Persian-speaking adults 55 years of age or older who were living in the community were eligible to participate in a 22-week, double-blind study of parallel groups of patients with AD. The main efficacy measures were the change in the Alzheimer’s Disease Assessment Scale—cognitive subscale and Clinical Dementia Rating Scale—Sums of Boxes scores compared with baseline. Adverse events (AEs) were systematically recorded. Participants were randomly assigned to receive a capsule saffron 30 mg/day (15 mg twice per day) or donepezil 10 mg/day (5 mg twice per day).

Results

Saffron at this dose was found to be effective similar to donepezil in the treatment of mild-to-moderate AD after 22 weeks. The frequency of AEs was similar between saffron extract and donepezil groups with the exception of vomiting, which occurred significantly more frequently in the donepezil group.

Conclusion

This phase II study provides preliminary evidence of a possible therapeutic effect of saffron extract in the treatment of patients with mild-to-moderate Alzheimer’s disease. This trial is registered with the Iranian Clinical Trials Registry (IRCT138711051556N1).     

Simultaneous species identification and detection of methicillin resistance in staphylococci using triplex real-time PCR assay

For rapid identification of methicillin-resistant Staphylococcus aureus, molecular methods are generally targeting mecA and species-specific genes. Sa442 DNA fragment is a popular species-specific target. However, recently, there have been few reports on S. aureus isolates that are negative for Sa442 fragment; therefore, use of single gene or DNA-fragment-specific polymerase chain reaction (PCR) for identification of microbial isolate may result in misidentification. This study includes CoA gene in parallel with Sa442 marker for identification of S. aureus. This further improves the specificity of the assay by checking for 2 determinants simultaneously for the identification of S. aureus and can prevent misidentification of S. aureus isolates lacking Sa442 DNA fragment. In this study, the newly developed triplex real-time PCR assay was compared with a quadruplex conventional gel-based PCR assay using the same primer sets in both assays. The dual-labeled TaqMan probes (ProOligo, France) for these primers were specifically designed and used in a real-time PCR assay. The clinical isolates (n = 152) were subjected to both PCR assays. The results obtained from both assays proved that the primer and probe sets were 100% sensitive and 100% specific for identification of S. aureus and detection of methicillin resistance. This triplex real-time PCR assay represents a rapid and powerful method for S. aureus identification and detection of methicillin resistance.     

Cortical activity during speech and non-speech oromotor tasks: A magnetoencephalography (MEG) study

We used whole-head magnetoencephalography to investigate cortical activity during two oromotor activities foundational to speech production. 13 adults performed mouth opening and phoneme (/pa/) production tasks to a visual cue. Jaw movements were tracked with an ultrasound-emitting device. Trials were time-locked to both stimulus onset and peak of jaw displacement. An event-related beamformer source reconstruction algorithm was used to detect areas of cortical activity for each condition. Beamformer output was submitted to iterative K-means clustering analyses. The time course of neural activity at each cluster centroid was computed for each individual and condition. Peaks were identified and latencies submitted for statistical analysis to reveal the relative timing of activity in each brain region. Stimulus locked activations for the mouth open task included a progression from left cuneus to left frontal and then right pre-central gyrus. Phoneme generation revealed the same sequence but with bilateral frontal activation. When time locked to jaw displacement, the mouth open condition showed left frontal followed by right frontal–temporal areas. Phoneme generation showed a complicated sequence of bilateral temporal and frontal areas. This study used three unique approaches (beamforming, clustering and jaw tracking) to demonstrate the temporal progression of neural activations that underlie the motor control of two simple oromotor tasks. These findings have implications for understanding clinical conditions with deficits in articulatory control or motor speech planning.     

Design and testing of statistical methods to classify the severity of steppage gait based on center of pressure data

In this research kinematics parameters derived from ground reaction forces were evaluated to limit differential diagnoses and measure the degree of disabilities during walking among neuropathic subjects. 25 neuropathic subjects affected by drop foot and 20 normal subjects were enrolled in the study. Each subject was tested in average 10±2 times for calculating kinetics parameters derived from ground reaction forces. The results revealed that the center of pressure displacement pattern in sole of foot can be a good index for differential diagnoses and measuring the degree of disabilities. This research can extend the clinical applications of ground reaction force plate and introduce suitable criteria to measure the degree of disability among neuropathic patients.     

Real-time PCR for Helicobacter pylori quantification and detection of clarithromycin resistance in gastric tissue from patients with gastrointestinal disorders

Helicobacter pylori gram-negative bacteria commonly infect the human gastrointestinal (GI) tract and are readily diagnosed by endoscopy. H. pylori infection causes a broad range of host symptoms from discomfort to significant GI disorders (GIDs). Severity of the clinical manifestations depends mainly upon bacterial load. In this cross-sectional study, we investigated the affects of 23S rRNA point mutations on H. pylori count in naturally infected human GI tissues. Two-hundred H. pylori patients with suspected GIDs were evaluated to determine bacteria concentration and presence of four known 23S rRNA point mutations, causing clarithromycin resistance. Gastric biopsy specimens were examined by rapid urease test and 16S rRNA-targeted PCR to identify H. pylori; then bacterial load was quantified by real-time PCR targeting wild type and known 23S rRNA mutations. Eighty-two percent of the samples were confirmed as H. pylori-positive, having 10(4)-10(12) colony-forming units (CFU)/ml. The 10(6) load was most strongly associated with peptidyltransferase point mutations of the 23S rRNA gene A2144G (p = 0.033), A2143G (p = 0.005), A2143C (p = 0.005), and A2142G (p = 0.015). Thus, our findings indicated that dominant 23S rRNA mutated H. pylori strains have the same growth rate as the wild type in a gastric environment.     

The expansion of health houses and fertility outcomes in rural Iran

Iran experienced a dramatic decline in fertility from 1984 to 2001, which was most rapid in rural areas. Although many attribute the decline to the government's active participation in providing family planning services, most services were provided after the initial fertility decline that took place after 1984. We assess the extent to which timing of exposure to basic healthcare is related to fertility outcomes. We estimate the association between a woman's age of exposure to a health house (clinic) and number of children, using the 2001 Iranian Household Expenditure and Income Survey and the 2006 Iranian Census, and the location and dates of operation for each rural health house. We also look at the probability of a woman's giving birth one year after a clinic opened in her village. We use Poisson and logistic multivariate regressions and we control for individual, household, and village characteristics. Exposure to a health house in a woman's most fertile years (20-34) is associated with an 18 percent decrease in number of children ever born relative to those exposed after age 40. This negative association gets progressively stronger as length of exposure increases. Our findings suggest that early exposure to health services in rural areas contributed to Iran's fertility decline.     

Relationship between sodium intensity and perfusion deficits in acute ischemic stroke

Purpose

To assess the relationship between sodium signal intensity changes and oligemia, measured with perfusion‐weighted imaging (PWI), in ischemic stroke patients.

Materials and Methods

Nine ischemic stroke patients (55 ± 13 years), four with follow‐up scans, underwent sodium and proton imaging 4–32 hours after symptom onset. Relative sodium intensity was calculated as the ratio of signal intensities in core (identified as hypertintense lesions on diffusion‐weighted imaging [DWI]) or putative penumbra (PWI‐DWI mismatch) to contralateral homologous regions.

Results

Sodium intensity increases in the core were not correlated with the severity of hypoperfusion, measured with either cerebral blood flow (rho = 0.157; P = 0.61) or cerebral blood volume (rho = ?0.234; P = 0.44). In contrast, relative sodium intensity was not elevated (4–7 hours 0.96 ± 0.07; 17–32 hours 1.00 ± 0.07) in PWI‐DWI mismatch regions.

Conclusion

Sodium signal intensity cannot be predicted by the degree of hypoperfusion acutely. Sodium intensity also remains unchanged in PWI‐DWI mismatch tissue, indicating preservation of ionic homeostasis. Sodium magnetic resonance imaging (MRI), in conjunction with PWI and DWI, may permit identification of patients with viable tissue, despite an unknown symptom onset time. J. Magn. Reson. Imaging 2011;33:41–47. © 2010 Wiley‐Liss, Inc.