A Low-cost Easy-to-Fabricate Sandwich-Structured Microdevice for Controllable Removal of Extracellular Cryoprotective Agents with High Efficiency

　　BACKGROUND: Osmotic shock upon the addition and removal of cryoprotectant agent (CPA) is a major source of cell damage during cryopreservation.

OBJECTIVE

Microfluidic device offers a new platform for CPA loading and unloading. The micro scale dimension makes possible to perform a detailed analysis and controllable removal of CPA with many advantages.

MATERIALS AND METHODS

A microfluidic device was developed for extracting dimethyl sulfoxide (DMSO) from the sample streamline. The device has two parallel channels separated by a polytetrafluoroethylene (PTFE) membrane and serves as the stable environment for CPA removal. A diffusion-based simulation model was used to characterize the CPA extraction. To support the experimental design and device optimization we developed analogous scheme to simulate by COMSOL Multiphysics.

RESULTS AND CONCUSION

The device can extract cryoprotectant in a mesoscale volume from cells and simplify the post-thaw sample handling. It has sufficient control on loading/unloading of CPAs by controlling the flow rate of cell stream/wash stream solutions via syringe pumps. Compared to other customary devices, this device is easy to fabricate and assemble, with features of high precision, reusability and low cost.

Amplification of Mitochondrial DNA for detection of Plasmodiumvivax in Balochistan

OBJECTIVE

To access a new step using PCR to amplify the targeted mtDNA sequence for detecting specifically Plasmodium vivax and its co-infections, false positive and false negative results with Plasmodium falciparum.

METHODS

In this study we have standardized a new technical approach in which the target mitochondrial DNA sequence (mtDNA) was amplified by using a PCR technique as a tool to detect Plasmodium spp. Species specific primers were designed to hybridize with cytochrome c oxidase gene of P. vivax (cox I) and P. falciparum (cox III). Two hundred blood samples were collected on the basis of clinical symptoms which were initially examined through microscopic analysis after preparing Giemsa stained thick and thin blood smears. Afterwards genomic DNA was extracted from all samples and was then subjected to PCR amplification by using species specific primers and amplified segments were sequenced for confirmation of results.

RESULTS

One-hundred and thirty-two blood samples were detected as positive for malaria by PCR, out of which 64 were found to be positive by PCR and 53 by both microscopy and PCR for P.vivax infection. Nine samples were found to be false negative, one P.vivax mono infection was declared as co infection by PCR and 3 samples identified as having P.falciparum gametes were confirmed as P.vivax by PCR amplification. Sensitivity and specificity were found to be 85% and 92% respectively.

CONCLUSIONS

Results obtained through PCR method were comparatively better and reliable than microscopy.

A PCR method based on 18S rRNA gene for detection of malaria parasite in Balochistan

OBJECTIVE

To establish a polymerase chain reaction method based on 18S ribosomal ribonucleic acid gene for the detection of plasmodium deoxyribonucleic acid in patients suffering from malaria symptoms.

METHODS

This cross-sectional study was conducted from September 2013 to October 2014 in district Quetta of Pakistan's Balochistan province. Blood samples were collected from patients suffering from general symptoms of malaria. A polymerase chain reaction-based technique was applied for the diagnosis of malaria and detection of responsible species in the patients who were suspected to carry the parasite. Performance of this polymerase chain reaction method was compared against the microscopy results. Parasite number was also calculated for microscopy positive samples.All samples after the genomic deoxyribonucleic acid isolation were subjected to polymerase chain reaction amplification and agarose gel electrophoresis.

RESULTS

Of the 200 samples, 114(57%) were confirmed as positive and 86(43%) as negative for malaria by microscopy. Polymerase chain reaction identified 124(62%) samples as positive and 76(38%) as negative for malaria. The comparative analysis of both diagnostic methods confirmed 109(54.5%) samples as positive by both techniques. Besides, 5(6.58%) samples were identified as false positive and 15(12.1%) samples as false negative by polymerase chain reaction. Sensitivity, specificity and positive predictive values for polymerase chain reaction in comparison to microscopy were 87.98%, 93.42% and 96%, respectively.

CONCLUSIONS

Polymerase chain reaction-based methods in malaria diagnosis and species identification were found to be more effective than other techniques.

Genome-wide significant linkage to IgG subclass responses against Plasmodium falciparum antigens on chromosomes 8p22-p21, 9q34 and 20q13

A genome-wide scan was conducted for the levels of total immunoglobulin G (IgG) and IgG subclasses directed against Plasmodium falciparum antigens in an urban population living in Burkina Faso. Non-parametric multipoint linkage analysis provided three chromosomal regions with genome-wide significant evidence (logarithm of the odds (LOD) score >3.6), and five chromosomal regions with genome-wide suggestive evidence (LOD score >2.2). IgG3 levels were significantly linked to chromosomes 8p22-p21 and 20q13, whereas IgG4 levels were significantly linked to chromosome 9q34. In addition, we detected suggestive linkage of IgG1 levels to chromosomes 18p11-q12 and 18q12-q21, IgG4 levels to chromosomes 1p31 and 12q24 and IgG levels to chromosome 6p24-p21. Moreover, we genotyped genetic markers located within the regions of interest in a rural population living in Burkina Faso. We detected genome-wide significant and suggestive linkage results when combining the two study populations for chromosomes 1p31, 6p24-p21, 8p22-p21, 9q34, 12q24 and 20q13. Because high anti-parasite IgG3 and low anti-parasite IgG4 levels were associated with malaria resistance, the chromosomal regions linked to IgG3 and IgG4 levels are of special interest. Although the results should be confirmed in an independent population, they may provide new insights in understanding both the genetic control of IgG production and malaria resistance.

First birth following natural IVF/ICSI treatment in Ireland

The first reported delivery following a natural cycle ICSI in Ireland is described. This technique has the potential to provide successful treatment for a selected group of patients.

Clinical pregnancy from a vitrified/warmed human blastocyst

The first pregnancy after vitrification of a human blastocyst (day 5 of embryo culture) was reported by Yokota et al. in 2000. Since then more attention has been given to the technique of vitrification and its safe application in ART. To the best of our knowledge, this is the first report of a clinical pregnancy resulting in a live birth from the transfer of a vitrified/ warmed human blastocyst in the Republic of Ireland.

Malaria resistance genes are associated with the levels of IgG subclasses directed against Plasmodium falciparum blood-stage antigens in Burkina Faso

Background

HBB, IL4, IL12, TNF, LTA, NCR3 and FCGR2A polymorphisms have been associated with malaria resistance in humans, whereas cytophilic immunoglobulin G (IgG) antibodies are thought to play a critical role in immune protection against asexual blood stages of the parasite. Furthermore, HBB, IL4, TNF, and FCGR2A have been associated with both malaria resistance and IgG levels. This suggests that some malaria resistance genes influence the levels of IgG subclass antibodies.

Methods

In this study, the effect of HBB, IL4, IL12, TNF, LTA, NCR3 and FCGR2A polymorphisms on the levels of IgG responses against Plasmodium falciparum blood-stage extract was investigated in 220 individuals living in Burkina Faso. The Pearson’s correlation coefficient among IgG subclasses was determined. A family-based approach was used to assess the association of polymorphisms with anti-P. falciparum IgG, IgG1, IgG2, IgG3 and IgG4 levels.

Results

After applying a multiple test correction, several polymorphisms were associated with IgG subclass or IgG levels. There was an association of i) haemoglobin C with IgG levels; ii) the FcγRIIa H/R131 with IgG2 and IgG3 levels; iii) TNF-863 with IgG3 levels; iv) TNF-857 with IgG levels; and, v) TNF1304 with IgG3, IgG4, and IgG levels.

Conclusion

Taken together, the results support the hypothesis that some polymorphisms affect malaria resistance through their effect on the acquired immune response, and pave the way towards further comprehension of genetic control of an individual’s humoral response against malaria.

Genetic variations in genes involved in heparan sulphate biosynthesis are associated with Plasmodium falciparum parasitaemia: a familial study in Burkina Faso

Background

There is accumulating evidence that host heparan sulphate proteoglycans play an important role in the life cycle of Plasmodium through their heparan sulphate chains, suggesting that genetic variations in genes involved in heparan sulphate biosynthesis may influence parasitaemia. Interestingly, Hs3st3a1 and Hs3st3b1 encoding enzymes involved in the biosynthesis of heparan sulphate are located within a chromosomal region linked to Plasmodium chabaudi parasitaemia in mice. This suggests that HS3ST3A1 and HS3ST3B1 may influence P. falciparum parasitaemia in humans.

Methods

Polymorphisms within HS3ST3A1 and HS3ST3B1 were identified in 270 individuals belonging to 44 pedigrees and living in Burkina Faso. Linkage and association between parasitaemia and the polymorphisms were assessed with MERLIN and FBAT. A genetic interaction analysis was also conducted based on the PGMDR approach.

Results

Linkage between P. falciparum parasitaemia and the chromosomal region containing HS3ST3A1 and HS3ST3B1 was detected on the basis of the 20 SNPs identified. In addition, rs28470223 located within the promoter of HS3ST3A1 was associated with P. falciparum parasitaemia, whereas the PGMDR analysis revealed a genetic interaction between HS3ST3A1 and HS3ST3B1. Seventy-three significant multi-locus models were identified after correcting for multiple tests; 37 significant multi-locus models included rs28470223, whereas 38 multi-locus models contained at least one mis-sense mutation within HS3ST3B1.

Conclusion

Genetic variants of HS3ST3A1 and HS3ST3B1 are associated with P. falciparum parasitaemia. This suggests that those variants alter both the function of heparan sulphate proteoglycans and P. falciparum parasitaemia.

Evidence for epistasis between hemoglobin C and immune genes in human P. falciparum malaria: a family study in Burkina Faso

Hemoglobin C (HbC) has been recently associated with protection against Plasmodium falciparum malaria. It is thought that HbC influences the development of immune responses against malaria, suggesting that the variation at the HbC locus (rs33930165) may interact with polymorphic sites in immune genes. We investigated, in 198 individuals belonging to 34 families living in Burkina Faso, statistical interactions between HbC and 11 polymorphisms within interleukin-4 (IL4), IL12B, NCR3, tumor necrosis factor (TNF) and lymphotoxin-α (LTA), which have been previously associated with malaria-related phenotypes. We searched for multilocus interactions by using the pedigree-based generalized multifactor dimensionality reduction approach. We detected 29 multilocus interactions for mild malaria, maximum parasitemia or asymptomatic parasitemia after correcting for multiple tests. All the single-nucleotide polymorphisms studied are included in several multilocus models. Nevertheless, most of the significant multilocus models included IL12B 3' untranslated region, IL12Bpro or LTA+80, suggesting that those polymorphisms play a particular role in the interactions detected. Moreover, we identified six multilocus models involving NCR3 that encodes the activating natural killer (NK) receptor NKp30, suggesting an interaction between HbC and genes involved in the activation of NK cells. More generally, our findings suggest an interaction between HbC and genes influencing the activation of effector cells for phenotypes related to mild malaria.

Prevalence of hepatitis C virus (HCV) genotypes in Balochistan

A molecular study was conducted to investigate the prevalence of Hepatitis C virus genotypes in HCV infected population of Balochistan. Forty HCV seropositive samples belonging to seven different locations of Balochistan were collected from different health care centres. Qualitative analysis of these samples using PCR resulted in 28 positive samples. The PCR positive samples were subjected to genotyping using the method described by Ohno et al (J Clin Microbiol 35:201-202, 1997) with minor modifications. Genotyping of 28 samples revealed three different genotypes including 3a, 3b and 1a. The most prevalent genotype was 3a with rate of 50% followed by genotype 3b and 1a, respectively. Nine samples remained untyped, suggesting the need of further investigation of genotypes in this region. It has been proposed that sequencing of these samples may be helpful to unreveal these genotypes and further epidemiology of HCV genotypes. Further more, extensive and large scale studies are needed to understand the epidemiology of HCV genotypes, as no such study has been carried in this province.

Occipital activation in glyceryl trinitrate induced migraine with visual aura

A case of migraine is presented with visual aura triggered on two separate occasions by glyceryl trinitrate (GTN). Positron emission tomography was carried out during the second triggering session. Activation in the primary visual area of the occipital cortex was demonstrated during the aura. This is the first published case of migraine aura triggered reproducibly by GTN.

New onset migraine with a brain stem cavernous angioma

A case of new onset migraine is described following a pontine bleed from a cavernous angioma.

Liposome encapsulated prostaglandin E1 in erectile dysfunction: correlation between in vitro delivery through foreskin and efficacy in patients

OBJECTIVES

To test the delivery of prostaglandin E1 (PGE1) in novel transdermal liposomal formulations through foreskin and to determine whether there is a correlation between in vitro transdermal absorption and in vivo efficacy in patients with erectile dysfunction.

METHODS

The in vitro transdermal absorption of PGE1 through excised foreskin from liposomal formulations was tested in diffusion cells using radiolabeled drug. The in vivo studies were carried out on 5 patients (aged 54 to 70 years) in a double-blind, placebo-controlled fashion. The patients were treated topically on the penis with three different active formulations containing 0.05% PGE1 and a placebo at least 1 week apart. The change in systolic peak flow velocities in the cavernosal arteries after treatment was monitored by duplex color Doppler ultrasonography with spectral analysis every 15 minutes for 1 hour.

RESULTS

The permeability coefficient (Kp) of PGE1 from the three liposomal formulations tested was found to be 0. 10, 1.66, and 3.82 x 10(-4) cm/hr, respectively. Peak systolic flow velocities in the deep cavernosal arteries of patients increased significantly compared with preapplication values (0.05 < P < or = 0.1) after application of two of the transdermal liposomal PGE1 formulations tested (the two with the highest Kp). The highest mean peak systolic flow velocity was achieved at 45 minutes after application of the formulations. The most effective formulation in this study resulted in a sevenfold increase in mean flow velocity compared with baseline values.

CONCLUSIONS

Topical application of PGE1 in a novel transdermal liposomal delivery system can enhance penetration of the drug into the deep cavernosal bodies and increase peak systolic flow velocities in patients with erectile dysfunction. The transdermal flux and permeability of PGE1 measured in vitro correlate well with the color Doppler ultrasound results in patients. The efficacy of a formulation in the development process may be predicted from in vitro absorption studies.

Cytodiagnosis of Campylobacter pylori in Papanicolaou-stained imprints of gastric biopsy specimens

The use of Papanicolaou-stained touch preparations of gastric antral biopsies for the identification of Campylobacter pylori was examined using specimens obtained from 63 consecutive patients with endoscopic evidence of antral gastritis, with the results compared to routine histologic examination and Warthin-Starry silver staining. Organisms were readily identifiable in the Papanicolaou-stained imprints of the gastric mucus. The sensitivity in detecting organisms was 92.5% for the Warthin-Starry-stained sections, 71.4% for the Papanicolaou-stained imprints and 100% for both techniques combined. False-negative imprints were attributed to poor smears and/or the submission of duodenal tissue rather than antral biopsies. Properly performed touch preparations stained by the Papanicolaou method are a cost-effective adjunct to Warthin-Starry-stained section for improving the sensitivity of gastric biopsies for the diagnosis of C pylori.

Uterine prolapse and renal dysfunction

We report 2 cases of complete uterine prolapse and bilateral severe hydronephrosis. Although vaginal hysterectomy corrected the obstruction the development of post-obstruction atrophy was associated with hypertension and moderate renal failure. Early diagnosis and correction are required to prevent these sequelae.

Direct revascularization of acute myocardial infarction by implantation of left internal mammary artery into infarcted left ventricular myocardium

This is a preliminary report. Clearly, the internal mammary artery implanted into the infarcted anterolateral portion of the wall of the left ventricle has been of help in decreasing the size of the infarction and in maintaining the life of the dogs and normal function six hours after a large left ventricular wall myocardial infarction had been created. More animals need to be studied at the end of six hours, eight hours, and ten hours after implantation. More studies are needed to learn if ligation of the coronary veins at the same time as the arteries is beneficial or not. Two internal mammary arteries may act better than one when implanted side by side into a 5 by 5 centimeter infarction. In man, both internal mammary arteries and the right gastroepiploic artery could be used to revascularize acute myocardial infarctions in the posterior and anterolateral parts of the left ventricle.