Tissue-engineered calcium alginate patches in the repair of chronic chinchilla tympanic membrane perforations

OBJECTIVE: Chronic tympanic membrane perforations are a common problem in the United States. A high number of these cases results from placement of pressure equalization tubes. These perforations may initially be treated with paper patch techniques and although safe and well tolerated, the procedure demonstrates poor efficacy. The ideal treatment for small perforations should be rapid, minimally invasive, and efficacious. Calcium alginate-based tissue engineered tympanic membrane patches represent an attractive option, but in vivo data are required. METHODS: A controlled prospective study of tympanic membrane perforation repair using a well-known chinchilla model of chronic tympanic membrane perforation was performed. Calcium alginate-based tympanic membrane patches were created using computer-aided design techniques. A previously described chinchilla model of chronic tympanic membrane perforations was used to create stable perforations ranging from 2 to 5 mm. Ears with chronic perforations were divided into three groups: control (no patch), paper patch, and calcium alginate plugs. At 10 weeks postimplantation, all animals were killed and inspected both grossly and histologically for healing. RESULTS: In the chinchilla model, the alginate grafts demonstrated significantly improved healing rates over both the untreated control group (spontaneous repair) and the paper patch group; nine of 13 healed in the alginate group versus two of nine healed in the paper patch group (P < .05) versus one of 11 healed in the control group (P < .05). CONCLUSION: Calcium alginate tympanic membrane perforation patches offer a significant advantage in the repair of chronic perforations over traditional techniques in the chinchilla perforation model and may offer attractive opportunities in the clinical setting.     

The pathophysiology of cholesteatoma

The pathogenesis of middle ear cholesteatoma continues to be highly debated. In recent years, there has been a substantial improvement in the understanding of the pathophysiology of this disease. This chapter provides a summary of the history and evolution of cholesteatoma and a review of the recent literature that pertains to the pathophysiology of congenital and acquired cholesteatoma. An emphasis is placed on the mechanism of osteolysis and the factors predictive of aggressiveness and recidivism.     

Primary Mycobacterium tuberculosis complex cutaneous infection: report of two cases and literature review.

Compared to other organs, skin is an uncommon site of tuberculosis involvement. In the era of HIV infection, increased intravenous drug abuse, and the use of immunosuppressive therapy for various systemic diseases, tuberculosis in all its forms, including skin tuberculosis, has reemerged. We report two cases of primary cutaneous tuberculosis in immunocompetent patients and review the literature of all cases described since 1935.     

Hepatitis C virus and the lung: implications for therapy

Hepatitis C virus (HCV) infection is a chronic blood-borne disease that affects > 4,000,000 individuals in the United States. The majority of individuals with HVC infection acquire a chronic hepatitis that predisposes them to the complications of cirrhosis and hepatoma. Chronic HCV infection is, however, associated with multiple extrahepatic manifestations as well, including recently recognized effects on the lung. These include primary effects on lung function, as well as secondary effects in the settings of progressive liver disease and drug treatment for HCV. In this article, we discuss the emerging clinical data that support a role for HCV infection in lung disease, describe the multiple pulmonary manifestations of this viral infection, and outline the therapies available for specific pulmonary complications of chronic HCV infection.     

Estimation of the elastic modulus of child cortical bone specimens via microindentation

Purpose: Non-pathological child cortical bone (NPCCB) studies can provide clinicians with vital information and insights. However, assessing the anisotropic elastic properties of NPCCB remains a challenge for the biomechanical engineering community. For the first time, this paper provides elastic moduli values for NPCCB specimens in two perpendicular directions (longitudinal and transverse) and for two different structural components of bone tissue (osteon and interstitial lamellae).

Materials and Methods: Microindentation is one of the reference methods used to measure bone stiffness. Here, 8 adult femurs (mean age 82 ± 8.9 years), 3 child femurs (mean age 13.3 ± 2.1 years), and 16 child fibulae (mean age 10.2 ± 3.9 years) were used to assess the elastic moduli of adult and child bones by microindentation.

Results: For adult specimens, the mean moduli measured in this study are 18.1 (2.6) GPa for osteons, 21.3 (2.3) GPa for interstitial lamellae, and 13.8 (1.7) GPa in the transverse direction.

For child femur specimens, the mean modulus is 14.1 (0.8) GPa for osteons, lower than that for interstitial lamellae: 15.5 (1.5) GPa. The mean modulus is 11.8 (0.7) GPa in the transverse direction. Child fibula specimens show a higher elastic modulus for interstitial lamellae 15.8 (1.5) than for osteons 13.5 (1.6), with 10.2 (1) GPa in the transverse direction.

Conclusion: For the first time, NPCCB elastic modulus values are provided in longitudinal and transverse directions at the microscale level.     

Emerging concepts on the epigenetic and transcriptional regulation of the Kiss1 gene

Kisspeptin and its receptor have been implicated as critical regulators of reproductive physiology, with humans and mice without functioning kisspeptin systems displaying severe pubertal and reproductive defects. Alterations in the expression of Kiss1 (the gene encoding kisspeptin) over development, along with differences in Kiss1 expression between the sexes in adulthood, may be critical for the maturation and functioning of the neuroendocrine reproductive system and could possibly contribute to pubertal progression, sex differences in luteinizing hormone secretion, and other facets of reproductive physiology. It is therefore essential to understand how Kiss1 gene expression develops and what possible regulatory mechanisms govern the modulation of its expression. A number of recent studies, primarily in rodent or cell line models, have focused on the contributions of epigenetic mechanisms to the regulation of Kiss1 gene expression; thus far, mechanisms such as DNA methylation, histone acetylation, and histone methylation have been investigated. This review discusses the most recent findings on the epigenetic control of Kiss1 expression in adulthood, the evidence for epigenetic factors affecting Kiss1 expression during puberty and development, and findings regarding the contribution of epigenetics to the sexually dimorphic expression of Kiss1 in the hypothalamus.     

Quality Characteristics of Noodles Produced from Wheat Flour and Modified Starch of African Breadfruit (Artocarpus altilis) Blends

Wheat flour and modified-starch from African breadfruit (MS) were used in ratios of 100:0; 90:10; 80:20; 70:30; 60:40 and 50:50 to produce noodles. Chemical composition, culinary and sensory attributes of the noodles were investigated. The protein, fat, ash, crude fiber, moisture and calorific values of the flour noodles ranged from 4.76 to 0.33%, 0.35 to 0.57%, 0.83 to 0.57%, 0.53 to 0.57%, 8.03 to 0.15% and 349.51 to 355.81 kcal/100 g respectively. Moisture content increased with increasing addition of MS and later reduced. Addition of MS flour up to 30% had no significant effect on the overall acceptance of noodles. The results showed that MS flour can be incorporated up to 30% for noodles to improve the nutrient value without affecting the acceptability. There were no significant difference (p < 0.05) in the sensory attributes of the noodles up till 30% level of inclusion with MS.     

Functional Properties,Nutritional and Sensory Qualities of Maize-Based Snack (Kokoro) Supplemented with Protein Hydrolysate Prepared from Pigeon Pea (Cajanus Cajan) Seed

Kokoro is a popular maize-based snack in Nigeria, which is consumed by adults and children but characterized by low protein content. The snacks were produced from blends of maize flour supplemented with protein hydrolysate from pigeon pea at 100:0 (control), 95:5, 90:10, 85:15, and 80:20. Flour blends were evaluated for functional and pasting properties, while snacks were analyzed for proximate composition and sensory qualities. Proximate analysis results showed significant (p < 0.05) increase in protein (9.64–11.12%), fat (13.40–20.17%), ash (1.83–2.38%) content, and energy value (431.84–468.97 kcal/100 g), while fiber (1.19–0.96%) and carbohydrate (68.17–60.74%) content decreased with inclusion of protein hydrolysate. No significant difference (p < 0.05) occurred in the sensory qualities of products from 100% maize and 80:20 flour blend. Hence, acceptable Kokoro snacks from an 80:20 (maize: protein hydrolysate) blend have been formulated, which could enhance the nutritional wellness of the target consumers.     

Cost-threshold analyses of the National AIDS Demonstration Research HIV prevention interventions

OBJECTIVE: The goal of the multisite National AIDS Demonstration Research (NADR) program was to reduce the sexual and drug injection-related HIV risks of out-of-treatment injection drug users and their sex partners. Previous analyses have established that the NADR interventions were effective at changing participants' risky behaviors. This study was to determine whether the NADR program also was cost-effective. METHODS: Data from eight NADR study sites were included in the analysis. A mathematical model was used to translate reported sexual and injection-related behavior changes into an estimate of the number of infections prevented by the NADR interventions and then to calculate the corresponding savings in averted HIV/AIDS medical care costs and quality-adjusted years of life, assuming United States values for these parameters. Because cost data were not collected in the original NADR evaluation, the savings in averted medical care costs were compared with the cost of implementing a similar intervention program for injection drug users. RESULTS: The eight NADR interventions prevented approximately 129 infections among 6629 participants and their partners. Overall, the NADR program would be cost saving (i.e. provide net economic savings) if it cost less than US$2107 per person and would be cost-effective if it cost less than US$10,264 per person. Both of these estimates are considerably larger than the US$273 per person cost of the comparison intervention. There was substantial cross-site variability. CONCLUSIONS: The results of this analysis strongly suggest that the NADR interventions were cost-saving overall and were, at the very least, cost-effective at all eight sites. In the United States and other developed counties, investments in HIV-prevention interventions such as these have the potential to save substantial economic resources by averting HIV-related medical care expenses among injection drug users.     

Regulation of Kiss1 expression by sex steroids in the amygdala of the rat and mouse

Kisspeptin (encoded by the Kiss1 gene) is an important regulator of reproduction. In rodents, Kiss1 is expressed in two hypothalamic regions, the arcuate nucleus and anteroventral periventricular/ periventricular continuum, where it is regulated by sex steroids. However, the distribution, regulation, and functional significance of neural kisspeptin outside of the hypothalamus have not been studied and are poorly understood. Here, we report the expression of Kiss1 in the amygdala, predominantly in the medial nucleus of the amygdala (MeA), a region implicated in social and emotional behaviors as well as various aspects of reproduction. In gonadally intact rats and mice, Kiss1-expressing neurons were identified in the MeA of both sexes, with higher Kiss1 expression levels in adult males than females in diestrus. In rats, Kiss1 expression in the MeA changed as a function of the estrous cycle, with highest levels at proestrus. Next, we tested whether Kiss1 in the MeA is regulated by the circulating sex steroid milieu. Kiss1 levels in the MeA were low in gonadectomized mice and rats of both sexes, and treatment with either testosterone or estradiol amplified Kiss1 expression in this region. Testosterone's inductive effect on Kiss1 expression in the MeA likely occurs via estrogen receptor-dependent pathways, not through the androgen receptor, because dihydrotestosterone (a nonaromatizable androgen) did not affect MeA Kiss1 levels. Thus, in rodents, Kiss1 is expressed and regulated by sex steroids in the MeA of both sexes and may play a role in modulating reproduction or brain functions that extend beyond reproduction.