Taxonomic discordance of immersive realities in dentistry: A systematic scoping review.: Taxonomic discordance of immersive realities

OBJECTIVES

This review aimed to map taxonomy frameworks, descriptions, and applications of immersive technologies in the dental literature.

DATA

The Preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) guidelines was followed, and the protocol was registered at open science framework platform (https://doi.org/10.17605/OSF.IO/H6N8M).

SOURCES

Systematic search was conducted in MEDLINE (via PubMed), Scopus, and Cochrane Library databases, and complemented by manual search.

STUDY SELECTION

A total of 84 articles were included, with 81% between 2019 and 2023. Most studies were experimental (62%), including education (25%), protocol feasibility (20%), in vitro (11%), and cadaver (6%). Other study types included clinical report/technique article (24%), clinical study (9%), technical note/tip to reader (4%), and randomized controlled trial (1%). Three-quarters of the included studies were published in oral and maxillofacial surgery (38%), dental education (26%), and implant (12%) disciplines. Methods of display included head mounted display device (HMD) (55%), see through screen (32%), 2D screen display (11%), and projector display (2%). Descriptions of immersive realities were fragmented and inconsistent with lack of clear taxonomy framework for the umbrella and the subset terms including virtual reality (VR), augmented reality (AR), mixed reality (MR), augmented virtuality (AV), extended reality, and X reality.

CONCLUSIONS

Immersive reality applications in dentistry are gaining popularity with a notable surge in the number of publications in the last 5 years. Ambiguities are apparent in the descriptions of immersive realities. A taxonomy framework based on method of display (full or partial) and reality class (VR, AR, or MR) is proposed.

CLINICAL SIGNIFICANCE

Understanding different reality classes can be perplexing due to their blurred boundaries and conceptual overlapping. Immersive technologies offer novel educational and clinical applications. This domain is fast developing. With the current fragmented and inconsistent terminologies, a comprehensive taxonomy framework is necessary.

Anatomical, Histological, and Immunohistochemical Description of the Abomasum in One-Humped Adult Camel (Camelus dromedary) in the South of Iraq

The camel is an important mammal, especially in the Middle EAST, although it has received less attention than other mammals and ruminants. Due to the lack of studies in this field, the current research was designed to investigate the morphological, histological, and immunohistochemical of one-humped camel's stomach. In this study, the third chamber (abomasum) of the stomach in adult one-humped camels (Camelus dromedaries) were evaluated (n=12). The morphological study of the third chamber showed that it consisted of two parts, the letter J, where the front part was found to be tubular, the outer surface is smooth, swollen, and transparent, while the inner surface has longitudinal folds with a low height. The posterior part is spherical, and the inner surface is divided into two regions. Histological study showed that the abomasum consists of four layers and is lined with simple columnar epithelium. The lamina property is composed of loose connective tissue. It contains different glands that, according to their location from the abomasum, where cardiac, Fundus, and pyloric glands are found, as well as stomach cells such as neck cells, mucous cells, chief cells, and parietal cells. In contrast, the sub mucosa layer is composed of loose connective tissue. It was also observed that the muscular layer is developed and contained from two layers, a circular inner and the outer one is longitudinal. It was also noted that the fourth layer is composed of loose connective tissue. The histochemical study showed a positive response to the PAS reagent.

Isolation of Pseudomonas aeruginosa from Persistent Bacterial Coinfection of a COVID-19 Patients with Molecular Detection of Antibiotics Resistance Genes

Pseudomonas aeruginosa (P. aeruginosa) have a considerable risk to public health in the world, due to its high ability to develop resistance to different classes of antibiotics. It has been discovered as a prevalent coinfection pathogen that causes sickness exacerbation in COVID-19 patients. This study aimed to determine the prevalence of P. aeruginosa from COVID-19 patients in Al Diwaniyah province, Iraq and to identify its genetic resistance pattern. 70 clinical samples were obtained from severe cases of patients (RT-PCR positive for SARS-COV-2 on a nasopharyngeal swab) who attended Al Diwaniyah Academic Hospital. 50 P. aeruginosa bacterial isolates were detected via microscopic examination, routine cultured and biochemical testing, then validated by the VITEK-2 compact system. VITEK reported 30 positive results, which later confirmed through molecular detection using 16s RNA specific for detection and a phylogenetic tree.20 isolates had positive PCR findings and 5 isolates submitted to GenBank with accession numbers OL314557.1, OL314556.1, OL314555.1, OL314554.1, OL314553.1.For antibiotic resistance genes, the number of the isolates containing blaOXA-1 and blaCTX-M 18 (90 percent) and 16 (80 percent) respectively. To study its adaptation in a SARS-CoV-2 infected environment, genomic sequencing investigations were undertaken with phenotypic validation. In conclusion, we demonstrate that multidrug resistant P. aeruginosa play an important role in in vivo colonization in COVID-19 patients and could be one of the causes of death of these patients which indicates the great challenge to clinicians in the facing of this serious disease.

Sequencing identifies a distinct signature of circulating microRNAs in early radiographic knee osteoarthritis

OBJECTIVE

MicroRNAs act locally and systemically to impact osteoarthritis (OA) pathophysiology, but comprehensive profiling of the circulating miRNome in early vs late stages of OA has yet to be conducted. Sequencing has emerged as the preferred method for microRNA profiling since it offers high sensitivity and specificity. Our objective was to sequence the miRNome in plasma from 91 patients with early [Kellgren-Lawrence (KL) grade 0 or 1 (n = 41)] or late [KL grade 3 or 4 (n = 50)] symptomatic radiographic knee OA to identify unique microRNA signatures in each disease state.

DESIGN

MicroRNA libraries were prepared using the QIAseq miRNA Library Kit and sequenced on the Illumina NextSeq 550. Counts were produced for microRNAs captured in miRBase and for novel microRNAs. Statistical, bioinformatics, and computational biology approaches were used to refine and interpret the final list of microRNAs.

RESULTS

From 215 differentially expressed microRNAs (FDR < 0.01), 97 microRNAs showed an increase or decrease in expression in ≥85% of samples in the early OA group as compared to the median expression in the late OA group. Increasing this threshold to ≥95%, seven microRNAs were identified: hsa-miR-335-3p, hsa-miR-199a-5p, hsa-miR-671-3p, hsa-miR-1260b, hsa-miR-191-3p, hsa-miR-335-5p, and hsa-miR-543. Four novel microRNAs were present in ≥50% of early OA samples and had 27 predicted gene targets in common with the prioritized set of predicted gene targets from the 97 microRNAs, suggesting common underlying mechanisms.

CONCLUSION

Sequencing of well-characterized patient cohorts produced unbiased profiling of the circulating miRNome and identified a unique panel of 11 microRNAs in early radiographic knee OA.

Therapeutic effects of mesenchymal stem cells on cutaneous leishmaniasis lesions caused by Leishmania major

OBJECTIVES

Leishmania major (L. major) is a cutaneous leishmaniasis causative agent. Current chemotherapeutic methods are not totally effective in treatment of this disease. The immunomodulation and tissue repairing capability of mesenchymal stem cells (MSCs), ease of isolation, detection and in vitro culture, have encouraged biologists to use MSCs for cell therapy in different infections such as cutaneous leishmaniasis.

METHODS

BALB/c mice (6-8 weeks old) were infected with L. major then divided into four groups and treated with MSCs, Glucantime, Glucantime + MSCs, or PBS. Regression of lesions, potency of macrophages for phagocytosis, proliferation of immune cells against Leishmania soluble antigen, reduction of spleen parasite burden and healing of the lesions were evaluated on days 10, 20 and 30 of treatment.

RESULTS

The results indicated that the mice intralesionally injected with MSCs showed significant regression in the lesions produced by L. major by day 30. Proliferation of splenocytes stimulated with SLA (soluble leishmania antigen) in vitro in MSC-treated mice on day 20 was significantly higher than in the other groups. The potency of phagocytosis in macrophages of mice treated with MSCs was significantly higher by day 30 and healing of the lesions in this group of mice showed more progress on histopathological examinations. Spleen parasite burden showed significant reduction in the mice treated with Glucantime + MSCs by day 30.

CONCLUSIONS

The results showed that including MSCs in treatment of cutaneous leishmaniasis caused by L. major is a promising approach.

Aerosolised Mesenchymal Stem Cells Expressing Angiopoietin-1 Enhances Airway Repair

BACKGROUND

The aim of this study was to investigate the effects of MSCs and MSC-expressing ANGPT1 (MSC-pANGPT1) treatment via aerosolisation in alleviating the asthma-related airway inflammation in the rabbit model.

METHODS

Rabbits were sensitised and challenged with both intraperitoneal injection and inhalation of ovalbumin (Ova). MSCs and MSC-pANGPT1 cells were aerosolised into rabbit lungs using the MicroSprayer® Aerosolizer Model IA-1B 48 h after injury. The post mortem was performed 3 days following cell delivery. Histopathological assessments of the lung tissues and inflammatory response were quantitatively scored following treatments.

RESULT(S)

Administration of aerosolised MSCs and MSC-pANGPT1 were significantly reduced inflammation of the airways (p < 0.001), as reflected by improved of structural changes such as thickness of the basement membrane, epithelium, mucosa and sub-mucosa regions. The airway inflammation score of both treatment groups revealed a significant reduction of inflammation and granulocyte infiltration at the peribronchiale and perivascular regions (p < 0.05). Administration of aerosolised MSCs alone was resulted in significant reduction in the levels of pro-inflammatory genes (IL-4 and TGF-β) while treatment with aerosolised MSC-pANGPT1 led to further reduction of various pro-inflammatory genes to the base-line values (IL4, TNF, MMP9 and TGF-β). Treatment with both aerosolised MSCs and MSC-pANGPT1 cells was also alleviated the number of airway inflammatory cells in the bronchoalveolar lavage (BAL) fluid and goblet cell hyperplasia.

CONCLUSION(S)

Our findings suggest that treatment with MSCs alone attenuated airway inflammation and structural changes of the airway. Treatment with MSC-pANGPT1 provided an additional effect in reducing the expression levels of various pro-inflammatory genes. Both of these treatment enhancing airway repair and therefore may provide a basis for the development of an innovative approach for the treatment and prevention of airway inflammatory diseases.

The role of age and mode of delivery in the STEPS intervention: a longitudinal pilot-study in treatment of posttraumatic stress symptoms in Danish survivors of sexual assault

Background: The STEPS programme has been succesfully implemented as a group-based treatment of trauma symptoms after rape for adolescents. The STEPS intervention was translated from Dutch to Danish and offered to adults in addition to adolescents as well as an individual intervention in addition to a group-based intervention at a Danish Centre for Rape Victims through 2011 to 2014. The programme was translated from Dutch to Danish and expanded to adults in addition to adolescents as well as to an individual intervention in addition to a group-based intervention at a Danish Centre for Rape Victims through 2011 to 2014. Objective: The present study observes  development in trauma symptoms and ICD-11 diagnostic status during an adapted version of the intervention programme 'STEPS' for survivors of sexual assault. Methods: A prospective uncontrolled study was conducted, monitoring symptoms of posttraumatic stress and other trauma-related symptomatology before treatment, after treatment and at 6 and 12 months' follow up for 103 referrals receiving individual or group-based STEPS. Tentative diagnoses of posttraumatic stress disorder (PTSD) and complex PTSD were assigned to participants according to the ICD-11 to observe the development in diagnostic status across time, and multilevel modelling was used to assess the development of symptom severity and to assess the moderating effect of age-group and mode of delivery. Results: A loglinear function representing large and statistically significant decline in symptomatology over time provided the best fit for all measures of trauma-related symptomatology. The decline was not moderated by age-group or mode of intervention. Dropout rates were independent of mode of intervention and age. Conclusion: The adaption of the STEPS programme to adults and as an individual intervention is feasible and maintains effect sizes comparable to those observed in the original intervention. Further research using randomized controlled trials is needed to ascribe the observed effect to the STEPS programme.

Prospective evaluation of the diagnostic potential of LipL32 based latex agglutination test for Bovine leptospirosis

The Livestock Sector of India plays an important role in livelihood security and socioeconomic development of rural households. Leptospirosis is an important zoonotic disease responsible for septicaemia, interstitial nephritis, jaundice, abortion, reproductive problem in most of the animal species. Reproductive disturbances in bovine population is most often restricted to investigation of brucellosis, however apart from brucellosis, there are many undiagnosed diseases like leptospirosis that takes a toll in the reproductive anomalies of cattle and buffalo. Hence, the present study was elucidated to screen the seroprevalence of Leptospira in cattle and buffalo in various hamlets of North India using a user friendly screening test i.e. LipL32 latex agglutination test. The overall seropositivity was found to be 26.01% (230/884) in case of bovine in this study and the LipL32 LAT showed a profound sensitivity and specificity with level of 94.97% and 99.53% respectively.

Maternal anaemia and maternal, fetal, and neonatal outcomes in a prospective cohort study in India and Pakistan

OBJECTIVE

To describe the association of maternal anaemia with maternal, fetal, and neonatal outcomes.

DESIGN

Prospective cohort study.

SETTING

Rural India and Pakistan.

POPULATION

Pregnant women residing in the study catchment area.

METHODS

We performed an analysis of a prospective pregnancy registry in which haemoglobin is commonly obtained as well as maternal, fetal, and neonatal outcomes for 42 days post-delivery. Women 40 years or older who delivered before 20 weeks or had a haemoglobin level of <3.0 g/dl were excluded. Our primary exposure was maternal anaemia, which was categorised in keeping with World Health Organization criteria based on a normal (≥11 g/dl), mild (>10-10.9 g/dl), moderate (7-9.9 g/dl) or severe (<7 g/dl). haemoglobin level. The primary maternal outcome was maternal death, the primary fetal outcome was stillbirth, and the primary neonatal outcome was neonatal mortality <28 days.

RESULTS

A total of 92 247 deliveries and 93 107 infants were included, of which 87.8% were born to mothers who were anaemic (mild 37.9%, moderate 49.1%, and severe 0.7%). Maternal mortality (number per 100 000) was not associated with anaemia: normal 124, mild 106, moderate 135, and severe 325 (P = 0.64). Fetal and neonatal mortality was associated with severe anaemia: stillbirth rate (n/1000)-normal 27.7, mild 25.8, moderate 30.1, and severe 90.9; P < 0.0001; 28-day neonatal mortality (n/1000)-normal 24.7, mild 22.9, moderate 28.1, and severe 72.6 (P < 0.0001). Severe maternal anaemia was also associated with low birthweight (<2500 and <1500 g), preterm birth, and postpartum haemorrhage.

CONCLUSION

Severe maternal anaemia is associated with higher risks of poor maternal, fetal, and neonatal outcomes but other degrees of anaemia are not. Interventions directed at preventing severe anaemia in pregnant women should be considered.

TWEETABLE ABSTRACT

Severe maternal anaemia is associated with adverse fetal and neonatal outcomes in low/middle-income countries.

Intestinal parasitic infections frequency in referred patients to a large teaching hospital, Khuzestan, Southwest, Iran, 2017

Intestinal parasitic infections (IPIs) are among the most important infectious diseases in Iran. A cross sectional study was designed to determine frequency of intestinal parasites among referrals to a large teaching hospital in Khuzestan, Southwest of Iran, 2017. A total number of 5613 stool samples were examined through direct smear and formalin-ether concentration methods to detect possible parasitic infections. Samples consisted of 2643 (47.09%) male and 2970 (52.91%) female. A total of 1468 (26.15%) samples were positive (13.11% male and 13.4% female) and 4145 (73.85%) were negative. The results also showed that 255 of samples had more than one type of parasite (mix infections). Counting single and mix parasite infections, the total number of positive cases reached to 1723. Helminthes parasites were present in 12 (0.7%) cases, while intestinal protozoan parasites were in 1711 (99.3%) cases. Almost equally, pathogenic and nonpathogenic parasites infected 860 (49.91%) and 863 (50.09%) of patients, respectively. The frequency for helminthes was determined at 0.52% with Hymenolepis nana and Enterobius vermicularis however, Giardia lamblia in 38.54% and Entamoeba histolytica/dispar at 10.68% were concluded as protozoa elements. The IPIs frequency was recorded in female and male patients at 49.16% and 50.14%, respectively. According to the current results the infection rate of intestinal parasites has been significantly reduced especially for helminths infections in this region possibly due to public attention to health issues such as; increased awareness of people, improvement of sanitation, seasonal variations, health education and personal hygiene.

Subcutaneous veins depth measurement using diffuse reflectance images

Intravenous (IV) procedures are often difficult due to the poor visualization of subcutaneous veins. Because existing vein locators lack the ability to assess depth, and also because mis-punctures and poor vascular access remain problematic, we propose an imaging system that employs diffuse reflectance images at three isosbestic wavelengths to measure both the depth and thickness of subcutaneous veins. This paper describes the proposed system as well as proof-of-principle experimental demonstrations. We initially introduce the working principle and structure of the system. All measurements were based on the Monte Carlo (MC) method and accomplished by referring an optical density (OD) ratio to a multi-layer diffuse reflectance model. Results were all validated by comparative ultrasound measurements. Experimental trials included 11 volunteers who were subjected to both ultrasound measurements and the proposed optical process to validate the system's applicability. However, the unreliability of the "thickness" measurement of the vein may be due to the fact that the veins have collapsible walls - so excess pressure by the transducer will give a false thickness.

Device-associated infections in a paediatric intensive care unit in Pakistan

This study assessed the effect of implementation of active infection control and surveillance on the occurrence of device-associated infections (DAIs) in a paediatric intensive care unit (PICU) from 2012 to 2015. There were 1378 patients, equating to 4632 patient-days, on the PICU, and 29 DAI episodes, giving an incidence rate of 2.1% and an incidence density rate of 6.26 per 1000 patient-days. The rates of central-line-associated bloodstream infections, ventilator-associated pneumonia and catheter-related urinary tract infections were 7/1000 central-line-days, 1.17/1000 ventilator-days and 0.24/1000 urinary-catheter-days, respectively. Despite the overall low rate of DAIs in the PICU, there was a relatively high rate of central-line-associated bloodstream infections.

Virulence loss and amastigote transformation failure determine host cell responses to Leishmania mexicana

The effect of alterations in virulence and transformation by long-term in vitro culture of Leishmania mexicana promastigotes on infectivity and immune responses was investigated. Fresh parasite cultures harvested from Balb/c mice were passaged 20 times in vitro. Infectivity was decreased and was completely avirulent after 20 passages. The qPCR results showed a down-regulation of GP63, LPG2, CPC, CPB2, CPB2.8, CHT1, LACK and LDCEN3 genes after passage seven concomitant with a reduced and absence of infectivity by passages seven and 20, respectively. Parasites at passages one and 20 are referred to as virulent and avirulent, respectively. The growth of avirulent and virulent parasite was affected by conditioned media derived from macrophages or monocytes infected with parasites for 2 h. Giemsa staining showed the failure of avirulent but not virulent parasites to transform to the amastigote stage in infected host cells with both virulent and avirulent modulating the expression of CCL-22, Tgad51, Cox2, IL-1, IL-10, TGF-β, TNF-α, Rab7, Rab9 and A2 genes; virulent but not avirulent L. mexicana significantly up-regulated Th2-associated cytokines, but down-regulated Rab7 and Rab9 gene expression. In conclusion, a model for L. mexicana is reported, which is of potential value in studying host-parasite interaction.

Monitoring polio supplementary immunization activities using an automated short text messaging system in Karachi, Pakistan

PROBLEM

Polio remains endemic in many areas of Pakistan, including large urban centres such as Karachi.

APPROACH

During each of seven supplementary immunization activities against polio in Karachi, mobile phone numbers of the caregivers of a random sample of eligible children were obtained. A computer-based system was developed to send two questions--as short message service (SMS) texts--automatically to each number after the immunization activity: "Did the vaccinator visit your house?" and "Did the enrolled child in your household receive oral polio vaccine?" Persistent non-responders were phoned directly by an investigator.

LOCAL SETTING

A cluster sampling technique was used to select representative samples of the caregivers of young children in Karachi in general and of such caregivers in three of the six "high-risk" districts of the city where polio cases were detected in 2011.

RELEVANT CHANGES

In most of the supplementary immunization activities investigated, vaccine coverages estimated using the SMS system were very similar to those estimated by interviewing by phone those caregivers who never responded to the SMS messages. In the high-risk districts investigated, coverages estimated using the SMS system were also similar to those recorded--using lot quality assurance sampling--by the World Health Organization.

LESSONS LEARNT

For the monitoring of coverage in supplementary immunization activities, automated SMS-based systems appear to be an attractive and relatively inexpensive option. Further research is needed to determine if coverage data collected by SMS-based systems provide estimates that are sufficiently accurate. Such systems may be useful in other large-scale immunization campaigns.

Effects of black seed oil on resolution of hepato-renal toxicity induced bybromobenzene in rats

OBJECTIVE

Volatile halocarbon, bromobenzene (BB), is frequently encountered in table-ready foods as contaminants residues. The objective of this study was to investigate whether black seed oil could attenuate hepato-renal injury induced by BB exposure.

MATERIALS AND METHODS

The evaluation was done through measuring liver oxidative stress markers: reduced glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA). Hepatic succinate dehydrogenase (SDH), lactate dehydrogenases (LDH) and glucose-6-phosphatase (G-6-Pase) were estimated. Serum aspartate and alanine aminotransferases (AST, ALT) and alkaline phosphatase were also evaluated. Kidney function indices; blood urea nitrogen (BUN), creatinine, serum protein, nitric oxide (NO), Na-K-adenosine triphosphatase (Na+-K+-ATPase) and phospholipids were done. Liver and kidney histopathological analysis and collagen content were analyzed for results confirmation.

RESULTS

Treatment with black seed oil (BSO) alleviated the elevation of GSH, SDH, LDH, G-6-Pase, serum protein, NO, Na+-K+-ATPase, phospholipids levels and attenuated MDA, SOD, AST, ALT and ALP. Diminution of collagen content and improvement in liver and kidney architectures were observed.

CONCLUSIONS

BSO enhanced the hepato-renal protection mechanism, reduced disease complications and delayed its progression. Further studies are needed to identify the molecules responsible for its pharmacological effect.  

Malachite green induces genotoxic effect and biochemical disturbances in mice

BACKGROUND AND OBJECTIVES

Malachite green (MG) is a triarylaminmethane dye used in the fish industry as an anti-fungal agent. Concern over MG is due to the potential for consumer exposure, suggestive evidence of tumor promotion in rodent liver, and suspicion of carcinogenicity based on structure-activity relationships. In order to evaluate the risks associated with exposure to MG, we examined the mutagenicity and biochemical effect of MG.

MATERIALS AND METHODS

For genotoxic effect we use the doses 27, 91, 272 and 543 mg/kg b.wt. for different period of time (7, 14, 21 and 28 days) to evaluate chromosomal aberrations in mouse somatic and germ cells as well as sister chromatid exchanges in bone marrow cells. For DNA fragmentation assay from mouse liver the same doses of MG were used for 28 days. For measuring biochemical parameters such as glycolysis and gluconeogenesis enzyme pathways, antioxidant indices, hepatic marker enzymes, total protein, glucose, glycogen levels and liver function enzyme activities were evaluated. Mice were treated orally up to 28 days with the two high doses of MG 272 and 543 mg/kg b.wt.

RESULTS AND CONCLUSIONS

Our results show that MG induce elevation in the percentage of SCE's and chromosomal aberrations (p < 0.01) after treatment with the high doses for long period of time. MG also induces DNA damage in mice liver in a dose dependent manner. Beside, MG treatment either in low or high doses causes biochemical disturbances in the major glucolytic-gluconeogenic pathways, hepatic marker enzymes, depleted glutathione and increased free radical as determined by increasing lipid peroxide. Histopathological observations revealed that MG induced sinusoidal, congestion, focal necrosis and degenerating in hepatic cells, hypertrophy and vacuolization followed by necrosis and cirrhosis.

Fragility fractures in the elderly: Evolving approaches in the NHS

Fragility fractures account for a significant proportion of trauma admissions and clinic attendances in the UK. Hip fractures constitute a major part of these fractures followed by wrist, spine and humerus. With the increasing elderly population and increasing life expectancy, incidences of these fractures have increased proportionately. Hip fractures cause significant morbidity and mortality because of existing medical co-morbidities or perioperative complications. In order to decrease the overall incidence of osteoporotic fractures and improve outcome of surgical treatment, different approaches to prevention and treatment are currently evolving throughout the NHS. These include primary prevention through management of osteoporosis and secondary prevention aimed at treating osteoporosis and reducing further fractures. In this article, we highlight the different care pathways that could effectively decrease the incidence of fragility fractures as well as the morbidity and mortality in these patients.

Immunogenicity of MHC Class I Peptides Derived from Leishmania mexicana Gp63 in HLA-A2.1 Transgenic (HHDII) and BALB/C Mouse Models

BACKGROUND

Leishmania is an intracellular parasite infecting humans and many wild and domestic animals. Recent studies have suggested an important role for cytotoxic T cells against Leishmania. Peptide-based vaccines targeting short sequences derived from known immunogenic proteins have been shown to elicit cellular immune responses against disparate pathogens.

METHODS

We predicted four HLA-A2 peptides derived from L. mexican/major gp63 and tested these in HHD II mice, as well as four peptides for mouse MHC class I from the same proteins tested in BALB/ mice.

RESULTS

The results revealed immunogenicity for three of the four peptides predicted for HLA-A2. Immunisation with these peptides, along with IFA, induced CTL responses detected by standard 4-hour cytotoxicity assay and significantly upregulated the production of IFN-γ. When HHDII mice were injected IM with L. mexicana gp63 cDNA and splenocytes were restimulated with blasts loaded with the immunogenic peptides, two of the peptides were able to induce significant level of IFN-γ detected by ELISA. None of the peptides predicted for Balb/c mouse MHC class I elicited CTL activity or significantly upregulated the IFN-γ.

CONCLUSION

The results may help in developing a peptide-based vaccine, which can be applied alone or in combination with drugs against Leishmania.

Leishmania mexicana Gp63 cDNA Using Gene Gun Induced Higher Immunity to L. mexicana Infection Compared to Soluble Leishmania Antigen in BALB/C

BACKGROUND

Leishmaniasis is a worldwide disease prevalent in tropical and sub tropical countries. Many attempts have been made and different strategies have been approached to develop a potent vaccine against Leishmania. DNA immunisation is a method, which is shown to be effective in Leishmania vaccination. Leishmania Soluble Antigen (SLA) has also recently been used Leishmania vaccination.

METHODS

The immunity generated by SLA and L. mexicana gp63 cDNA was compared in groups of 6 mice, which were statistically analysed by student t- test with the P-value of 0.05. SLA was administered by two different methods; intramuscular injection and injection of dendritic cells (DCs) loaded with SLA. L. mexicana gp63 cDNA was administered by the gene gun.

RESULTS

Immunisation of BALB/c mice with L. mexicana gp63 resulted in high levels of Th1-type immune response and cytotoxic T lymphocytes (CTL) activity, which were accompanied with protection induced by the immunisation against L. mexicana infection. In contrast, administration of SLA, produced a mixed Th1/Th2-type immune responses as well as a high level of CTL activity but did not protect mice from the infection.

CONCLUSION

The results indicate higher protection by DNA immunisation using L. mexicana gp63 cDNA compared to SLA, which is accompanied by a high level of Th1 immune response. However, the CTL activity does not necessarily correlate with the protection induced by the vaccine. Also, gene gun immunisation is a potential approach in Leishmania vaccination. These findings would be helpful in opening new windows in Leishmania vaccine research.

Evaluation of the syndesmotic-only fixation for Weber-C ankle fractures with syndesmotic injury

BACKGROUND

With the length of the fibula restored and the syndesmosis reduced anatomically, internal fixation using a plating device may not be necessary for supra-syndesmotic fibular fractures combined with diastasis of inferior tibio-fibular joint. A retrospective observational study was performed in patients who had this injury pattern treated with syndesmosis-only fixation.

MATERIALS AND METHODS

12 patients who had Weber type-C injury pattern were treated with syndesmosis only fixation. The treatment plan was followed only if the fibular length could be restored and if the syndesmosis could be anatomically reduced. Through a percutaneous or mini-open reduction and clamp stabilization of the syndesmosis, all but one patient had a single tricortical screw fixation across the syndesmosis. Patients were kept non-weight-bearing for 6 weeks, followed by screw removal at an average of 8 weeks. Outcomes were assessed using an objective ankle scoring system (Olerud and Molander scale) and by radiographic assessment of the ankle mortise.

RESULTS

At a mean follow-up of 13 months, the functional outcome score was 75. Excellent to good outcomes were noted in 83% of the patients. Ankle mortise was reduced in all cases, and all but one fibular fracture united without loss of fixation. Six patients had more than one malleolar injury, needing either screw or anchor fixations. One patient had late diastasis after removal of the syndesmotic screw and underwent revision surgery with bone grafting of the fibula. This was probably due to early screw removal, before union of the fibular fracture had occurred.

CONCLUSION

We recommend syndesmosis-only fixation as an effective treatment option for a combination of syndesmosis disruption and Weber type-C lateral malleolar fractures.

Management of ruptured amoebic liver abscess: 22-years experience

BACKGROUND

Amoebiasis affects approximately 10% of the population all over the world. Amoebic liver abscess (ALA) is the commonest complication of amoebiasis affecting 3-9% victims. It is an ancient disease as Hippocrates notified large hepatic abscesses likely to be amoebic abscesses. Objective of this study was to see the efficacy of conservative treatment in the management of ruptured amoebic liver abscess.

METHODS

Record of 1,083 patients of amoebic liver abscess, who were treated and managed at Liaquat University Hospital between January 1986 and December 2007, was reviewed retrospectively. Amongst these, 36 (3.32%) patients, found to have intra-peritoneal rupture of the liver abscess were included in this study. The record of these patients was reviewed. The patients were divided into group A and B depending upon the mode of treatment employed. Group A included 16 (44.44%) patients in whom exploratory laparotomy was performed while group B included 20 (55.55%) patients who were treated conservatively.

RESULTS

Group A consisted of 16 (44.4%) patients who underwent laparotomy for acute peritonitis due to non-availability of ultrasound in the initial period of the study. In group B, all twenty patients were treated conservatively after a diagnosis of ruptured amoebic liver abscess made by ultrasound guided percutaneous aspiration of pus. These patients were treated with ultrasound guided aspiration of pus with placement of peritoneal drain under local anaesthesia. Six patients in group A died compared to one patient in group B. the overall mortality of ruptured amoebic liver abscess was 19.4%. It was higher in patients treated surgically (37.5%) compared to patients who were treated conservatively (5%).

CONCLUSION

Conservative treatment is an effective modality of treatment for ruptured liver abscess with minimum mortality and mortality if diagnosis is made early.

CTL responses to Leishmania mexicana gp63-cDNA vaccine in a murine model

Immunity to Leishmania is believed to be strongly dependent upon the activation of Th1 immune responses, although the exact role of cytotoxic T lymphocytes (CTLs) has not yet been determined. The aims of this study were to establish a suitable cytotoxicity assay to measure CTL activity and to compare immunity induced by Leishmania mexicana gp63 cDNA via i.m. injection and gene gun immunization in the BALB/c mouse model. The CTL activity was evaluated by short-term (51)Cr-release cytotoxicity assays against CT26 tumour cells transfected with L. mexicana gp63 cDNA and dendritic cells (DCs) loaded with soluble Leishmania antigen (SLA) as targets. The results clearly demonstrated that higher protection to L. mexicana infection was induced by gene gun DNA-immunization vs. i.m. injection. Cytotoxic T lymphocyte activity of splenocytes was observed in mice immunized either with L. mexicana gp63 cDNA or SLA and long-lived CTL activity was observed in immunized and/or re-challenged mice but not naïve mice infected with the parasite.

Safety and efficacy of total dose infusion of iron dextran in iron deficiency anaemia

AIMS

Intravenous iron is usually reserved for patients in whom oral administration has failed. Typically the calculated total dose is divided in to several fractions. Total dose infusion (TDI) of iron dextran is not commonly used due to the potential for serious side effects such as anaphylactic reactions.

METHODS

We identified 214 patients retrospectively, who were given TDI. Outcomes studied were: immediate side effects, improvement of haemoglobin and haematocrit.

RESULTS

The most frequent side effect of TDI was nausea with a rate of 2.2%. Headache, vomiting, chills and backache were seen in 1.1% of patients and about 0.5% of patients experienced fever and diarrhoea. No anaphylactic reaction was noted. Observed mean elevation of haematocrit was 5.3% and haemoglobin of 2.0 gm/dl (p < 0.0001).

CONCLUSION

TDI of iron dextran is a safe, potentially efficacious and convenient treatment in iron deficiency anaemia, in patients unresponsive or intolerant to oral iron.

Supra dietary levels of vitamins C and E enhance antibody production and immune memory in juvenile milkfish, Chanos chanos (Forsskal) to formalin-killed Vibrio vulnificus

Juveniles of milkfish, Chanos chanos (Forsskal), were fed two independent supra dietary levels of vitamins C (500 and 1500 mg kg(-1) feed, T1 and T2) and E (50 and 150 mg kg(-1), T3 and T4). Milkfish fed diets with supra (in addition to the vitamins present in the control diet) and normal levels (T5 containing 90 and 1.2mg of vitamins C and E, respectively, kg(-1) of feed) of vitamins were immunized (ip) with formalin-killed Vibrio vulnificus (FKVV). Priming and booster antibody responses to the injected bacterin were significantly (P<0.05) better in the milkfish juveniles fed supra dietary levels. Survival response of the experimental fish fed supra dietary levels of vitamins (T1, T2 and T3) was significantly (P<0.01) better than that of the control set. Protective response against virulent bacterial challenge of the vaccinated fish fed vitamin-supplemented diets (T2 and T3) was better than the control (T5) and T1 and T4. Memory factor reflecting immunological memory was superior in the fish fed vitamin-supplemented diets. Diets supplemented with either 1500 mg of Vitamin C or 50mg of Vitamin E kg(-1) produced the best antibody responses, final survival and protective response upon challenge. No conclusive inferences could be drawn on the growth responses from the experiment.

Epidemiological and etiological study of oral submucous fibrosis among gutkha chewers of Patna, Bihar, India

An etiological and epidemiological study of oral submucous fibrosis (OSMF) has been done in Patna, Bihar. Total 157 cases of OSMF and 135 control subjects were selected for study in the period of 2002-2004. It was observed that Male:Female ratio was 2.7:1. The youngest case of OSMF was 11 year old and the oldest one was 54 years of age. Maximum number of cases were belonging to 21-40 years of age and they were belonging to low or middle socioeconomic class. Most of the OSMF cases used heavy spices and chillies, where as control mild spices and chillies. Gutkha was the most commonly used by the OSMF cases only 3 per cent did not use any gutkha or other areca nut product where as 80 per cent control did not have any chewing habit. The OSMF cases used gutkha and other products 2-10 pouches per day and kept in the mouth for 2-10 minutes and they were using since 2-4 years. Most of the OSMF cases kept gutkha in the buccal vestibule or they chewed and swallowed it, only a small number of patients chewed and spitted it out. It was also observed that OSMF developed on one side of the buccal vestibule where they kept the chew and other side was normal.

Prostaglandin EP4 receptor agonist augments fixation of hydroxyapatite-coated implants in a rat model of osteoporosis

The reduced stability of hydroxyapatite (HA)-coated implants in osteopenic conditions is considered to be a major problem. We therefore developed a model of a boosted cementless implantation in osteopenic rats.

Twelve-week-old rats were either ovariectomised (OVX) or sham-operated (SO), and after 24 weeks plain or HA-coated implants were inserted. They were treated with either a prostaglandin EP4 receptor agonist (ONO-4819) or saline for one month.

The EP4 agonist considerably improved the osteoporosis in the OVX group. Ultrastructural analysis and mechanical testing showed an improvement in the implant-bone attachment in the HA-coated implants, which was further enhanced by the EP4 agonist. Although the stability of the HA-coated implants in the saline-treated OVX rats was less than in the SO normal rats, the administration of the EP4 agonist significantly compensated for this shortage. Our results showed that the osteogenic effect of the EP4 agonist augmented the osteoconductivity of HA and significantly improved the stability of the implant-bone attachment in the osteoporotic rat model.

Role of vitamins B6, B12 and folic acid on hyperhomocysteinemia in a Pakistani population of patients with acute myocardial infarction

BACKGROUND AND AIM

Pakistani people belong to an ethnic group which has the highest rate of coronary artery disease (CAD). We investigated the possible correlation between deficiency of vitamins B6, B12 or folic acid and hyperhomocysteinemia in Pakistani patients with acute myocardial infarction (AMI). A case-control study was carried out involving 224 AMI patients (age 30-70 years; 55 females and 169 males) and 126 normal healthy subjects (age 31-70 years; 35 females and 91 males).

METHODS AND RESULTS

Fasting venous blood was obtained from cases and controls. Serum was analyzed for folic acid and B12 using radioassays. Plasma was analyzed for pyridoxal phosphate (PLP; coenzymic form of B6) using a radioenzymatic assay and for total homocysteine using a fluorescence polarization immunoassay. Mean serum B12 concentration in AMI patients was found to be significantly lower than the mean for controls (241+/-185 pg/ml vs 608+/-341 pg/ml; p < 0.001). Mean serum folate level in patients was also found to be lower than controls (3.35+/-3.78 ng/ml vs 4.93+/-2.93 ng/ml), however, the differences were not statistically significant. Similarly, mean PLP concentration in plasma of cases (19.4+/-24.4 nmol/l) was lower than the concentration in controls (23.2+/-17.6 nmol/l), but the difference was not statistically significant. Mean plasma homocysteine level in AMI cases (18+/-8.36 micromol/l) was higher than the mean level in controls (16.4+/-4.9 micromol/l), but not to a significant extent. However, this mean homocysteine concentration in normal healthy subjects was among the highest reported in the literature and was significantly more than mean values reported in most Eastern and Western studies. Compared to controls, there was significantly greater deficiency of folate (32.5% vs 67.1%), B12 (3.2% vs 63.4%) and PLP (49.2% vs 74.1%) in AMI patients. Deficiencies of folate, B12 and PLP were defined as serum folate levels less than 3.5 ng/ml, serum levels of B12 less than 200 pg/ml and plasma PLP levels less than 20 nmol/l. Mean plasma homocysteine levels in smokers were found to be significantly higher in both cases and controls. Similarly, mean serum folate levels in smokers (compared to nonsmokers) were significantly lower in both cases and controls.

CONCLUSIONS

Substantial nutritional deficiencies of these three vitamins along with mild hyperhomocysteinemia, perhaps through an interplay with the classical cardiovascular risk factors (highly prevalent in this population), could be further aggravating the risk of CAD in the Pakistani population.

Nodavirus infection causes mortalities in hatchery produced larvae of Lates calcarifer: first report from India

Larvae (15 to 21 d post hatch, dph) of the Asian sea bass Lates calcarifer (Bloch) suffered heavy mortalities (60 to 90%) during the hatchery-rearing phase. Darkened and moribund larvae showed no evidence of bacterial or parasitic infections. Tissue sections of brain and spinal cord showed clear necrotic vacuolation. Electron microscopy revealed membrane-bound viral particles in the cytoplasm of the nerve cells. The viral particles measured 28 to 30 nm in diameter. Primer sets, designed for the amplification of the RNA2 segment of the piscine nodavirus coat protein gene, were used in the RT-PCR analysis of moribund larvae of 20 and 21 dph which produced the amplified product of 430 bp. The clinical manifestations, pathology and electron microscopy observations supported by the RT-PCR analysis suggest that the nerve necrosis was due to nodavirus infection in the larvae. This is the first report of piscine nodavirus infection from the Indian sub-continent.

Evaluation of Pseudomonas sp. PM 11 and Vibrio fluvialis PM 17 on immune indices of tiger shrimp, Penaeus monodon

Occurrence of widespread epizootics among cultured stock of shrimp has put research programmes on preventive approaches such as application of probiotics on a high priority in aquaculture. In the present study two bacteria, Pseudomonas sp. PM 11 and Vibrio fluvialis PM 17 were selected as candidate probionts from a pool of bacteria isolated from gut of farm reared sub-adult shrimp and tested for their effect on the immunity indicators of tiger shrimp. Sub-adult shrimp, weighing 14 to 22 g were treated in separate experiments with Pseudomonas sp. PM 11 and V. fluvialis PM 17 at 10(3) bacterial cells ml(-1) in the experimental shrimp culture tanks. One set of experimental animals was treated every 3 days and another set of animals every 7 days with each of the candidate probionts. Estimation of immunological indicators such as haemocyte counts, phenol oxidase and antibacterial activity showed declining trends. The haemocyte counts dropped from 31 x 10(3) to 65 x 10(3) ml(-1) on the first day to 4-16 x 10(3) ml(-1) on the 45th day. Similarly, the phenol oxidase activity declined from 12-32 units on the first day to 11-14 units on 45th day of the experiment. Antibacterial activity of haemolymph reduced to 46-67 percent on the 45th day of the experiment. The results of the study suggest that, the criteria used for the selection of putative probiotic strains in the present study, such as predominant growth on primary isolation media, ability to produce extracellular enzymes and siderophores, did not bring about the desired effect in vivo and improve the immune system in shrimp. Hence, new protocols have to be evolved for selection of microbe(s) as putative probiotics and that, detailed understanding of proven probiotics, employed presently on empirical basis may provide a clue on the selection procedure.

Impact of Gemcitabine and Cisplatin with radiotherapy in locally advanced or metastatic transitional cell carcinoma of urinary bladder

OBJECTIVE

The primary object of this study is to evaluate the efficacy and safety of Gemcitabine and Cisplatin along with radiotherapy in transitional cell carcinoma of urinary bladder.

PATIENTS AND METHODS

Twenty patients with locally advanced or metastatic TCC of urinary bladder were enrolled during the 22-months period from January, 1999 to October, 2000 and followed up till March 2002. Three patients received 4 cycles, five patients received 5 cycles and twelve patients received 6 cycles of Gemcitabine 1250 mg/m2 on day 1 and day 8 and Cisplatin 80 mg/m2 on day 1; administered every 3 weeks. No patient received prior chemotherapy, radiotherapy or surgery. However, four patients received prior intravesical chemotherapy. All patients received radiotherapy after completion of chemotherapy regimen.

RESULTS

Nineteen patients achieved complete response at the end of the treatment. The complete response rate was 95%. The confidence interval was at 95%, level of confidence ranged from 85% to 100%. Median duration of clinical benefit was 21 months. Six patients (30%) were documented neutropenia, three patients (15%) documented thrombocytopenia. No life threatening toxicity was observed.

CONCLUSION

Gemcitabine and Cisplatin along with radiotherapy in locally or metastatic Transitional cell carcinoma of urinary bladder, exhibited pronounced response rate among all the patients. The toxicity profile remained extremely low and disease free survival enhanced. The above investigation may further be continued at a larger scale encompassing a wide band of subjects.

Cardiac acceleration as a marker of vagal withdrawal in heart rate control during exercise in humans

OBJECTIVE

To investigate whether the time rate of change in heart rate i.e. cardiac acceleration, during aerobic exercise in human subjects could be used to differentiate vagal withdrawal from sympathetic stimulation.

METHODS

Fifteen male subjects exercised on a bicycle ergometer at 50 Watts (Step 1), then 100 Watts (Step 2), for 2 minutes each.

RESULTS

Heart rate (HR) was monitored from a resting value (mean +/- SD) of 80.3 +/- 12.9 to 113.8 +/- 13.6 beats min-1 in Step 1. In Step 2 exercise, HR increased from 113.8 +/- 13.6 to 145 +/- 20 beats min-1. At the initiation of Step 1, a rapid acceleration of HR was observed in the form of an overshoot response. In contrast to Step 1, a small overshoot response of cardiac acceleration was observed during Step 2. The difference between the mean cardiac acceleration at 10 seconds in Steps 1 and 2 was significant (2.40 +/- 0.19 and 0.71 +/- 0.12 beats min-1 sec-1, p<0.0001).

CONCLUSION

The initial vagal withdrawal of exercise-induced tachycardia, as a frontline adaptive mechanism, can be indirectly identified from HR transients using cardiac acceleration as a new marker.

Production, purification and some properties of Bac201, a bacteriocin-like inhibitory substance produced by Staphylococcus aureus AB201

Staphylococcus aureus AB201, a clinical isolate from wound pus, produced a bacteriocin-like inhibitory substance termed as Bac201, that was inhibitory to Streptococcus agalactiae, Enterococcus faecalis, Acinetobacter calcoaceticus, Neisseria meningitidis and a number of staphylococcal species. It was purified to homogeneity by ammonium sulfate precipitation, gel filtration (BioSil-SEC-125), and reversed-phase high performance liquid chromatography (Vydac C4). The native Bac201 was sized at approximately 170-kDa as determined by GF HPLC. Fraction-I (native Bac201), having antibacterial activity was also examined by transmission electron microscopy and appeared as globular structure showing resemblance with phage-like objects. The purification of Bac201 resulted in 466-fold increase in specific activity and recovery of 0.94% of total antibacterial activity. The purified Bac201 migrated as single band on SDS-PAGE with an estimated molecular mass of about 41-kDa. Bac201 was sensitive to proteolytic enzymes, resistant to heat and organic solvents, and active over a wide range of pH (2.5-10). The amino acid composition revealed a general resemblance with other reported high molecular mass bacteriocins and predominance of glycine (39%), proline (13%) and alanine (8%) residues. Further results showed that Bac201 has a bactericidal effect on sensitive cells which is not produced by either cell lysis or apparent loss of membrane permeability.

Efficacy of clarithromycin in preventing viridans streptococcal bacteremia following autologous stem cell transplantation

BACKGROUND

In a study involving 200 patients, we previously found that 17.5% of patients developed viridans streptococcal (VS) bacteremia following autologous peripheral blood stem cell transplantation (aPBSCT) when ciprofloxacin or ciprofloxacin plus ampicillin was used for prophylaxis.

PATIENTS AND METHODS

A retrospective evaluation of 100 consecutive recipients of aPBSCT was conducted to ascertain the incidence and outcome of VS bacteremia when a combination of ciprofLoxacin and clarithromycin was utilized for antimicrobiaL prophylaxis following transplantation. The 200 patients from our previous study, in which ciprofloxacin alone or ciprofloxacin with ampicillin was used for prophylaxis, were combined with the current group for the purpose of statistical analysis.

RESULTS

Streptococcus mitis was isolated from the blood of five individuals at a median of 5 days following stem cell infusion. Each of these patients was neutropenic and presented with fever. Three isolates demonstrated intermediate resistance to macrolides in vitro. However, all episodes of bacteremia were treated successfully with systemic antibiotic therapy.

CONCLUSION

Age, duration of neutropenia, type of underlying malignancy and type of conditioning chemotherapy regimen failed to have a significant impact on subsequent VS bacteremia. Only female sex and use of ciprofloxacin without clarithromycin as antimicrobiaL prophyLaxis predicted a significantly increased risk of VS bacteremia in both univariate and Logistic regression analyses.

Purification, characterization, and primary structure of four depressant insect-selective neurotoxin analogs from scorpion (Buthus sindicus) venom

Four depressant insect-selective neurotoxin analogs (termed Bs-dprIT1 to 4) from the venom of the scorpion Buthus sindicus were purified to homogeneity in a single step using reverse-phase HPLC. The molecular masses of the purified toxins were 6820.9, 6892.4, 6714.7, and 6657.1 Da, respectively, as determined by mass spectrometry. These long-chain neurotoxins were potent against insects with half lethal dose values of 67, 81, 103, and 78 ng/100 mg larva and 138, 160, 163, and 142 ng/100 mg cockroach, respectively, but were not lethal to mice even at the highest applied dose of 10 microg/20 g mouse. When injected into blowfly larvae (Sarcophaga falculata), Bs-dprIT1 to 4 induced classical manifestations of depressant toxins, i.e., a slow depressant flaccid paralysis. The primary structures of Bs-dprIT 1 to 4 revealed high sequence homology (60-75%) with other depressant insect toxins isolated from scorpion venoms. Despite the high sequence conservation, Bs-dprIT1 to 4 showed some remarkable features such as (i) the presence of methionine (Met(6) in Bs-dprIT1 and Met(24) in Bs-dprIT2 to 4) and histidine (His(53) and His(57) in Bs-dprIT1) residues, i.e., amino acid residues that are uncommon to this type of toxin; (ii) the substitution of two highly conserved tryptophan residues (Trp43 --> Ala and Trp53 --> His) in the sequence of Bs-dprIT1; and (iii) the occurrence of more positively charged amino acid residues at the C-terminal end than in other depressant insect toxins. Multiple sequence alignment, sequence analysis, sequence-based structure prediction, and 3D homology modeling studies revealed a protein fold and secondary structural elements similar to those of other scorpion toxins affecting sodium channel activation. The electrostatic potential calculated on the surface of the predicted 3D model of Bs-dprIT1 revealed a significant positive patch in the region of the toxin that is supposed to bind to the sodium channel.

Evaluation of Acetaminophen tablets by control test

Various pharmacopoeial and non-pharmacopoeial control test applied to Acetaminophen tablets were used to evaluate for the uniformity of weight, diameter, thickness, medicaments, hardness and friability. The tests were intended to check the compliance of the prepared tablets with the accepted specifications.

Isolation, structural, and functional characterization of an apoptosis-inducing L-amino acid oxidase from leaf-nosed viper (Eristocophis macmahoni) snake venom

The enzyme L-amino acid oxidase (LAO) from the leaf-nosed viper (Eristocophis macmahoni) snake venom was purified to homogeneity in a single step using high performance liquid chromatography on a Nucleosil 7C18 reverse phase column. The molecular mass of the purified enzyme was 58734.0 Da, as determined by matrix-assisted laser desorption/ionization mass spectrometry. The N-terminal amino acid sequence (ADDKNPLEEAFREADYEVFLEIAKNGL) and the chemical composition of the purified LNV-LAO shows close structural homology with other L-amino acid oxidases isolated from different snake venoms. The secondary structural contents analysis of LAO, established by means of circular dichroism, revealed ca. 49% alpha-helix, 19% beta-sheet, 10% beta-turn, and 22% random coil structure. The purified LNV-LAO not only retained its specific enzymatic activity (73.46 U/mg), determined against L-leucine as a substrate, but also exhibited potent haemolytic (1-10 microg/ml), edema- (MED 4.8 microg/ml) and human platelet aggregation-inducing (ED50 33 microg/ml) properties. Unlike other haemorrhagic snake venom L-amino acid oxidases, the LNV-LAO does not produce haemorrhage. In addition to these local effects, the purified LNV-LAO showed apoptosis-inducing activity in the MM6 cell culture assay. After 18 h treatment with 25-100 microg/ml of LAO, the typical DNA fragmentation pattern of apoptotic cells was observed by means of fluorescent microscopy and agarose gel electrophoresis.

Spectro- and electrochemical studies of some ruthenium and osmium complexes of 2-(2'-pyridyl)benzimidazole; complexes with intra-molecular charge transfer

Reaction of Ru3(CO)12, with 2-(2'-pyridyl)benzimidazole (HPBI) resulted in the formation of Ru(CO)3(HPBI) (I) complex. In presence of pyridine or dipyridine, the two derivatives [Ru(CO)3(HPBI)].Py (II) and [Ru(CO)3(HPBI)].dpy (III) were isolated. The corresponding reactions of Os3(CO)12 yielded only one single product; Os(CO)2(HPBI)2 (IV). Spectroscopic studies of these complexes revealed intramolecular metal to ligand CT interactions. Reactions of RuCl3 with HPBI gave three distinct products; [Ru(HPBI)2Cl2]Cl (V), [Ru(HPBI)(dipy)Cl2]C1 (VI) and [Ru(PBI)2(py)2]Cl (VII). The UV-vis studies indicated the presence of intramolecular ligand to metal CT interactions. Electrochemical investigation of the complexes showed some irreversible, reversible and quasi-reversible redox reactions due to tautomeric interconversions through electron transfer.

Folic acid supplementation

Neural tube defects represent one of a limited number of congenital conditions for which primary prevention strategies are available. Despite strong clinical evidence to support the preventive effect of supplementary folic acid given prior to conception and continued throughout the first 12 weeks of pregnancy, there is limited recent epidemiological data to support the effectiveness of national folic acid supplementation programs. Whether folic acid fortification of staple foods will provide a more effective means of achieving further reductions in the prevalence rates for this condition remains open to question. Recent advances associating folic acid supplementation, hyperhomocysteinaemia and neural tube defects provide a new insight into the possible pathological mechanism of this and possibly other related congenital conditions.

Trafficking of 'immune' CD4(+)/CD8(+)T-lymphocytes into the RENCA tumour microcirculation in vivo in mice

RENCA-IL-2 (Murine Renal Cell Carcinoma transfected with murine IL-2 gene) cells were rejected by immunocompetent (but not T-cell deficient) Balb/c mice, which developed 'immunity' to subsequent parental RENCA tumour cell challenge. Splenocytes adoptively transferred this immunity. CD4(+)and CD8(+)T-lymphocytes prepared from the spleens of 'tumour immune' mice were evaluated for their ability to traffic into the tumour environment using an in vivo model that enables visualization of events within the microvasculature. RENCA cells were implanted into the mouse cremaster muscle and the trafficking of syngeneic lymphocyte subpopulations, derived from naive and 'immune' animals, into both the RENCA tumour and the surrounding normal cremaster muscle microcirculation was measured by in vivo microscopy. Fluorescently labelled CD4(+)and CD8(+)T lymphocytes taken from the spleens of naive mice or mice previously immunized with RENCA-IL-2 were injected systemically into tumour-bearer mice. Naive effector cells migrated to, and flowed through both the tumour and the normal microcirculation, with negligible adhesion. However we observed the selective recruitment, localization and arrest of immune CD4(+)and CD8(+)T lymphocytes (P< 0.05) into the tumour microcirculation, and in some instances the subsequent extravasation of cells into the tumour interstitium. Lymphocyte rolling by 'immune' CD4(+)and CD8(+)T-cells in the tumour microcirculation was greatly reduced, suggesting impaired adhesion molecule expression on the tumour endothelium. This study clearly demonstrates, by direct in vivo microscopy assessment, the localization of effector cells, CD4(+)and CD8(+)lymphocytes into tumours.