Multiple Structural Transitions in Langmuir Monolayers of Charged Soft-Shell Nanoparticles.

We have investigated the morphologies of Langmuir layers of charged, polymeric hard-core/interlayer/soft-shell nanoparticles spread at the air-water interface. Depending on various mutual interactions, which are correlated to the areal densities of the deposited nanoparticles, we observed ordered patterns of nondense and closed-packed arrangements of core/interlayer/shell (CIS) nanoparticle ordering. At low areal densities, we found an almost regular distribution of the charged CIS nanoparticles on the water surface, which resulted from long-range repulsive electrostatic interactions between them. At higher areal densities, domains of more closely packed and ordered nanoparticles were formed, coexisting with regions of randomly and sparsely distributed nanoparticles. We relate these domains to the interplay of electrostatic repulsion and capillary attraction caused by the dipolar character of like-charged particles at the interface, allowing for a characteristic separation distance between nanoparticles of about 3-4 times the nanoparticle diameter. At relatively high areal densities, attractive van der Waals forces were finally capable of making nanoparticles to come in contact with each other, leading to densely packed patches of hexagonally ordered nanoparticles coexisting with regions of rather well-ordered nanoparticles separated by about 1 µm and regions of randomly and sparsely distributed nanoparticles. Intriguingly, upon re-expansion of the area available per nanoparticle, these densely packed patches disappeared, indicating that steric repulsion due to the presence of soft shells as well as long-range electrostatic repulsive forces were strong enough to assure reversibility of the morphological behavior.

Activation of migration of endogenous stem cells by erythropoietin as potential rescue for neurodegenerative diseases.

UNLABELLED: Neurodegenerative disorders such as Alzheimer's disease (AD) are characterized by progressive cognitive dysfunction and memory loss. There is deposition of amyloid plaques in the brain and subsequent neuronal loss. Neuroinflammation plays a key role in the pathogenesis of AD. There is still no effective curative therapy for these patients. One promising strategy involves the stimulation of endogenous stem cells. This study investigated the therapeutic effect of erythropoietin (EPO) in neurogenesis, and proved its manipulation of the endogenous mesenchymal stem cells in model of lipopolysaccharide (LPS)-induced neuroinflammation. METHODS: Forty five adult male mice were divided equally into 3 groups: Group I (control), group II (LPS untreated group): mice were injected with single dose of lipopolysaccharide (LPS) 0.8 mg/kg intraperitoneally (ip) to induce neuroinflammation, group III (EPO treated group): in addition to (LPS) mice were further injected with EPO in dose of 40 µg/kg of body weight three times weekly for 5 consecutive weeks. Groups were tested for their locomotor activity and memory using open field test and Y-maze. Cerebral specimens were subjected to histological and morphometric studies. Glial fibrillary acidic protein (GFAP) and mesenchymal stem cell marker CD44 were assessed using immunostaining. Gene expression of brain derived neurotrophic factor (BDNF) was examined in brain tissue. RESULTS: LPS decreased locomotor activity and percentage of correct choices in Y-maze test. Cerebral sections of LPS treated mice showed increased percentage area of dark nuclei and amyloid plaques. Multiple GFAP positive astrocytes were detected in affected cerebral sections. In addition, decrease BDNF gene expression was noted. On the other hand, EPO treated group, showed improvement in locomotor and cognitive function. Examination of the cerebral sections showed multiple neurons exhibiting less dark nuclei and less amyloid plaques in comparison to the untreated group. GFAP positive astrocytes were also reduced. Cerebral sections of the EPO treated group showed multiple branched and spindle CD44 positive cells inside and around blood vessels more than in LPS group. This immunostaining was negative in the control group. EPO administration increased BDNF gene expression. CONCLUSION: This study proved that EPO provides excellent neuroprotective and neurotrophic effects in vivo model of LPS induced neuroinflammation. It enhances brain tissue regeneration via stimulation of endogenous mesenchymal stem cells proliferation and their migration to the site of inflammation. EPO also up regulates cerebral BDNF expression and production, which might contributes to EPO mediated neurogenesis. It also attenuates reactive gliosis thus reduces neuroinflammation. These encouraging results obtained with the use of EPO proved that it may be a promising candidate for future clinical application and treatment of neurodegenerative diseases.

Two-dimensional refractive index and stresses profiles of a homogenous bent optical fiber.

We present a significant contribution to the theory of determining the refractive index profile of a bent homogenous optical fiber. In this theory we consider two different processes controlling the index profile variations. The first is the linear index variation due to stress along the bent radius, and the second is the release of this stress on the fiber surface. This release process is considered to have radial dependence on the fiber radius. These considerations enable us to construct the index profile in two dimensions normal to the optical axis, considering the refraction of light rays traversing the fiber. This theory is applied to optical homogenous bent fiber with two bending radii when they are located orthogonal to the light path of the object arm in the holographic setup (like the Mach-Zehnder interferometer). Digital holographic phase shifting interferometry is employed in this study. The recorded phase shifted holograms have been combined, reconstructed, and processed to extract the phase map of the bent optical fiber. A comparison between the extracted optical phase differences and the calculated one indicates that the refractive index profile variation should include the above mentioned two processes, which are considered as a response for stress distribution across the fiber's cross section. The experimentally obtained refractive index profiles provide the stress induced birefringence profile. Thus we are able to present a realistic induced stress profile due to bending.

The hematopoietic growth factor "erythropoietin" enhances the therapeutic effect of mesenchymal stem cells in Alzheimer's disease.

Alzheimer's disease is a neurodegenerative disorder clinically characterized by cognitive dysfunction and by deposition of amyloid plaques, neurofibrillary tangles in the brain. The study investigated the therapeutic effect of combined mesenchymal stem cells and erythropoietin on Alzheimer's disease. Five groups of mice were used: control group, Alzheimer's disease was induced in four groups by a single intraperitoneal injection of 0.8 mg kg(-1) lipopolysaccharide and divided as follows: Alzheimer's disease group, mesenchymal stem cells treated group by injecting mesenchymal stem cells into the tail vein (2 x 10(6) cells), erythropoietin treated group (40 microg kg(-1) b.wt.) injected intraperitoneally 3 times/week for 5 weeks and mesenchymal stem cells and erythropoietin treated group. Locomotor activity and memory were tested using open field and Y-maze. Histological, histochemical, immunohistochemical studies, morphometric measurements were examined in brain sections of all groups. Choline transferase activity, brain derived neurotrophic factor expression and mitochondrial swellings were assessed in cerebral specimens. Lipopolysaccharide decreased locomotor activity, memory, choline transferase activity and brain derived neurotrophic factor. It increased mitochondrial swelling, apoptotic index and amyloid deposition. Combined mesenchymal stem cells and erythropoietin markedly improved all these parameters. This study proved the effective role of mesenchymal stem cells in relieving Alzheimer's disease symptoms and manifestations; it highlighted the important role of erythropoietin in the treatment of Alzheimer's disease.

Dystocia in Friesian cows and its effects on postpartum reproductive performance and milk production.

A total of 1,243 records for 585 dairy Friesian cows from 1997-2004 were used to study the factors affecting dystocia and its effects on reproductive performance and milk production. The overall incidence of dystocia was 6.9%. The percentage of dystocia decreased with increasing live body weight, age, and parity of cows (P < 0.05); however, it increased with increasing birth weight of calves (P < 0.05). The highest percentage of dystocia was detected in winter season, but the least percentage was in summer season (P < 0.05). The percentage of incidence of dystocia was significantly (P < 0.05) higher with winter feeding compared to summer ration (8.2% vs. 5.1%). The percentage of incidence of dystocia was significantly (P < 0.05) higher with twinning than single calving (15.5% vs. 6.5%), while not significantly affected by the sex of born calves. Incidence of dystocia had adverse effects on reproductive performance and milk yield. The service interval, service period, days open, and calving interval were significantly (P < 0.05) longer in cows afflicted with dystocia compared to normal cows. The conception rate was lower (P < 0.05), but the number of service per conception was higher (P < 0.05) in cows afflicted with dystocia compared to normal cows (60.5% vs. 73.0% and 3.4 vs. 2.7, respectively). Average daily milk yield was lower (P < 0.05) by 1 kg for cows with incidence of dystocia compared to normal cows.

Prevention of beta-thalassemia in a large Pakistani family through cascade testing.

BACKGROUND: We report cascade testing of a large Pakistani family for beta-thalassemia alleles. The family was still practicing consanguineous marriages and was at risk of having more affected births. OBJECTIVE: The objective of this study was to show that identification of disease carriers in families with index cases in order to create awareness about disease and provide genetic counseling would result in reduction of the frequency of beta-thalassemia in Pakistan. METHODS: In this large family with an index case, 27 available living members were tested for beta-thalassemia. Carriers of the disease were detected by measuring hemoglobin indices, and amplification refractory mutation system polymerase chain reaction was used for mutation analysis. Genetic counseling was provided to members of this family. RESULTS: There were already 3 marriages between the carrier members and 1 between a carrier and noncarrier in this large family; 12 (44.4%) members were found to carry the mutant gene, representing a very high carrier rate compared to the 5.4% carrier frequency of beta-thalassemia in the general population of Pakistan. The family was counseled for prevention of affected births. The initially reluctant family gradually became cooperative and seriously attended the genetic counseling sessions. CONCLUSION: Cascade testing is more practical than general population screening in a country with limited health facilities where consanguineous marriages are practiced. This report emphasizes the need of extensive testing within families with index cases to identify the carriers of beta-thalassemia in order to reduce disease occurrence through awareness and genetic counseling.

Nebulizer therapy with antibiotics in chronic suppurative lung disease.

Aerosolized antibiotics have been shown to be a useful modality of treatment in patients with cystic fibrosis. In this investigation we examined the utility of this treatment in patients with other chronic suppurative lung disorders. These included forty patients, thirty men and ten women with chronic airway infection (27 with bronchiectasis, 6 with chronic abscess and 7 with chronic suppurative bronchitis). Pathogenic organisms were isolated from the affected part of the lung by a fiberoptic bronchoscopy using a sterile disposable bronchial microbiology brush. Cultures from these specimens were used to determine the appropriate antibiotic. A second control group of 20 patients was treated with systemic antibiotics alone. Both systemic and aerosolized antibiotics were administered in 20 patients. A statistically significant improvement in clinical, and ventilatory functions was recorded in the first group compared to the second. Nebulized antibiotics used as adjunctive therapy in association with systemic antibiotics may offer a therapeutic advantage in chronic suppurative lung diseases.

Immunologic characterization of two monoclonal antibodies reactive with repetitive carbohydrate epitopes of circulating Schistosoma mansoni egg antigen.

A panel of 60 monoclonal antibodies (MAbs) reactive with repetitive epitopes of species-specific Schistosoma mansoni soluble egg antigen (SEA) was tested for performance in detecting circulating egg antigens. Two MAbs, 114-5B1-A and 114-4D12-A, which were highly reactive with two different repetitive carbohydrate epitopes of soluble egg antigen, were found to detect circulating egg antigen in the sera of S. mansoni-infected mice. The two MAbs also showed strong reactivity with two high M(r) cercarial antigens present on the cercarial and schistosomular surface, while in the adult worms, antigens in the parenchyma were recognized. In two sandwich enzyme-linked immunosorbent assays (ELISA-5B1 and ELISA-4D12), each MAb was used as capture antibody and as conjugate, which resulted in assays with a lower detection level (0.2-0.4 ng) of the trichloroacetic acid-soluble fraction of soluble egg antigen (SEA-TCA)/ml. The antigen component(s) detected by ELISA-5B1 and ELISA-4D12 were 10,000 and 40,000 times more concentrated in the egg antigen than in the adult worm antigen, respectively. With both assays, in serum of heavily S. mansoni-infected mice, antigen became detectable from eight weeks postinfection (PI) onwards, with a striking increase at nine weeks PI.

Involuntary action of the external anal sphincter. Manometric and electromyographic studies.

The changes in the rectal neck (anal canal) pressure and electromyography (EMG) of the external anal sphincter and levator ani muscle were studied in 20 dogs before and after internal anal sphincter excision by 2 weeks and monthly up to 10 months. The rectal neck pressure dropped to 41% of the preoperative level. It was then gradually elevated from the beginning of the 1st month following excision till it reached 88% of the level before excision at the 10th month. The external sphincter EMG basal activity after internal sphincterectomy by 2 weeks showed a decrease in the amplitude of the slow and high potential waves. From the 1st to the 7th month after excision, changes in the frequency and amplitude of the waves occurred, and by the 10th month, the external sphincter showed the characteristics of the EMG of both the internal and external anal sphincters. The basal activity of the levator ani muscle increased at the 10th month. As reported previously, the changes in the rectal neck pressure and in the EMG of the external anal sphincter after internal sphincterectomy seem to be due to the histological changes in the muscle and include striated and smooth muscle fiber hypertrophy and proliferation. These changes adapt the external sphincter to serve the function of not only voluntary but also involuntary continence.

A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. The involuntary action of the external anal sphincter: histologic study.

The histologic changes in the external anal sphincter after internal anal sphincter excision were studied in 20 dogs. An external sphincter biopsy was taken before internal sphincterectomy and 2 weeks and monthly thereafter for 10 months. The excised material was studied microscopically after being stained with hematoxylin and eosin, Verhoeff-van Gieson and succinic dehydrogenase. 70% of external sphincter specimens before internal sphincter excision showed smooth muscle fibers scattered between the striated fibers. These smooth fibers could be responsible for the resting tone of the external sphincter. After internal sphincter excision, characteristic histologic changes could be identified in the external sphincter. From the 2nd week to the 5th month after excision, the external sphincter showed degenerative and hypertrophic changes. From the 6th to the 10th month, there were regeneration of the striated muscle fibers and increase in the number of smooth fibers so that by the 10th month a 'compound' muscle of striated and smooth fibers was identified. Two theories were put forward to explain the smooth fiber preponderance in the external sphincter after internal sphincter excision: mutant and replacement theories. The increased nonstriated element in the external sphincter seems to be a structural-functional adaptation so that the external sphincter takes on the involuntary function of the excised muscle.

Patterns, trends and future of international migration: some causes and consequences.

"This study examines the main trends of various models of international migration for the nineteenth and early twentieth centuries, and places emphasis on the volume and direction of various models of migration at present. Permanent migration, illegal migration in search of work and compulsory migration (refugees) are discussed in some detail with reference to the occasional difficulty of distinguishing between the various types of migration. When discussing the volume and sources of migration, the study indicates some of its motives and implications at origin and at destination and presents some of the future prospects and major factors that contribute to the continuation of the flow of the different types of migration." The geographical scope is worldwide.

Ambient temperature effects on brain and spinal cord acetylcholinesterase activity of two poikilotherms.

The changes in AChE activity and protein content following cold or heat exposure and heat death were determined in the brain and spinal cord of both Rana ridibunda and Chalcides ocellatus. Cold exposure (10 degrees C) caused a decrease in the enzyme activity and protein content of both animals. Exposure to heat (36-40 degrees C) increased markedly the AChE activity and the amount of protein in the two experimental animals. Heat death was found to be associated with a prominent decrease in enzyme activity and the protein level of the brain and spinal cord of the two poikilotherms.