Assessment of cyclone risk and case study of Gaja cyclone using GIS techniques and machine learning algorithms in coastal zone of Tamil Nadu, India

Cyclones can cause devastating impacts, including strong winds, heavy rainfall, storm surges, and flooding. The aftermath includes infrastructure damage, loss of life, displacement of communities, and ecological disruptions. Timely response and recovery efforts are crucial to minimize the socio-economic and environmental consequences of cyclones. To accelerate the time-consuming risk assessment process, particularly in geographically diverse regions, a blend of multi-criteria decision-making and machine learning models was utilized. This novel approach swiftly assessed cyclone risk and the impact of the Gaja cyclone in Nagapattinam, India. The method involved assigning weights to distinct criteria, unveiling notable vulnerability aspects like elevation, slope, proximity to the coast, distance from cyclone tracts, Lu/Lc, population density, proximity to cyclone shelters, household density, accessibility to healthcare facilities, NDVI, and levels of awareness. Daddavari, Ettugudi, Kodikarai, Vedharanyam, Velankanni, and Thirupoondi face high/extreme cyclone risk. Nagore, Nagapattinam, Pillai, Enangudi, and Sannanllur have low/no threat. To further enhance the precision of the study, machine learning algorithms like SVM, SAM, and MLC were deployed. These models were instrumental in generating pre- and post-cyclone land use maps. The influence of Gaja cyclones effects shows decreasing of agriculture land from 34% to 30%, aquaculture increase 1%, barren land decrease from 8% to 6%, Built-up land decrease from 15% to 13%, land with scrub and salt pan also decrease from 21% to 17% and 10%-8%. Mostly effect of Gaja cyclone is dramatic increase of water body from 8% to 21%. Conducting cyclone risk zone analysis and pre/post-cyclone Land Use Land Cover (LULC) detection in Nagapattinam offers valuable insights for disaster preparedness, infrastructure planning, and climate resilience. This study can enhance understanding of vulnerability and aid in formulating strategies to mitigate cyclone impacts, ensuring sustainable development in the region.

Assess the Risk Level of Acute Coronary Syndrome (ACS) Among Patients with Chest Pain in Emergency Department

Background: Fast and accurate chest pain risk stratification in the Emergency Department (ED) is critical. The HEART score predicts the short-term incidence of major cardiac events (MACE) in this population and divides them into three risk categories. Our aim was to describe the chest pain population, to characterize the subset of patients with acute coronary syndrome (ACS), and to assess the prognostic value of the Manchester triage system and the HEART score.Chest pain is a common symptom in all health care settings and may be due to a extensive variety of disease conditions. Some of those will be because of treatable causes, including musculoskeletal problems with favorable outcomes; others will be because of probably deadly life-threatening conditions, inclusive of acute coronary syndrome. Methods: Descriptive research design was adopted to conduct the study with( n=60) samples who met the inclusion criteria at Saveetha Medical College and Hospital. Samples were selected by convenience sampling Saveetha Medical College and Hospital, Chennai. A total of 60 Samples who met the inclusion criteria is selected by using convenience sampling technique. After selecting the sample, the investigator introduced him-self and explained the purpose of the study to the participants. Informed consent was obtained from the participants after assured confidentiality. The demographic and clinical variables were collected by using multiple choice questionnaires. Assess the risk level of acute coronary syndrome (ACS) by using HEART score immediately after receiving the chest pain patients with emergency. The data were collected, and score evaluation will take 10 -15 minutes after The data were tabulated and analyzed by descriptive and inferential statistics Result: The risk level of acute coronary syndrome (ACS) among patients with chest pain in emergency department. Study finding shows that out of 60 samples in risk level of acute coronary syndrome (ACS) among patients with chest pain in emergency department by using HEART Score 36(60%) had high risk, 13(21.7%) had intermediate risk and11(18.3%)had low risk. Conclusion: The chest pain is the most associate feature of major adverse cardiac events in the conditions. Chest pain is a common presentation at the Emergency Room. Rapid identification level of risk acute coronary syndrome (ACS)isacrucial component of thetriage. HEART Score is an efficient score in triaging acute chest pain patients at the Emergency Department

OP0187 COMPARATIVE EFFICACY OF NON-BIOLOGIC IMMUNOSUPPRESSANTS IN TAKAYASU ARTERITIS

Background

The choice of immunosuppressant (IS) in patients with Takayasu arteritis (TAK) is often arbitrary due to lack of comparison studies.

Objectives

In this retrospective, we aimed to compare the efficacy of 3 non biologic IS including azathioprine (AZA), mycophenolate mofetil (MMF) and methotrexate (MTX) in inducing and maintaining sustained remission in patients with TAK.

Methods

Patients with a diagnosis of TAK, attending our clinics between Jan 2000 and May 2019 were identified. Those who satisfied either ACR or Sharma’s classification or EULAR PRINTO PRES criteria and/or had angiographic evidence of Takayasu arteritis with a minimum 2 follow up visits were included. Patients who received upfront biologics were excluded. The patients were matched for parameters statistically different among three groups using propensity score analysis. Clinical details at the index visit defined as the time of initiation of first IS and follow up visits were prospectively recorded and retrospectively noted from electronic medical records. The primary outcomes were attainment of complete remission and relapses. Disease activity was assessed by Indian Takayasu arteritis score (ITAS), C-reactive protein and angiograms. Relapse was defined as ITAS-A(CRP) >=2 and/or progression in angiograms and/or escalation of steroid dose and/or switching of IS due to active disease. The baseline variables of patients receiving AZA, MMF and MTX were compared using chi square test or Mann Whitney U test. The comparative efficacy of IS to induce complete remission was calculated using logistic regression and presented as odds ratio (95% CI). The cumulative risk of relapse was calculated using Cox-proportional hazards model with hazards ratio and 95% confidence interval (CI) after adjusting for duration of symptoms and juvenile onset disease. The patients were censored at the time of relapse or time of switching to another IS or last follow up whichever was the earliest. AZA was arbitrary chosen as the reference drug for all the analysis. The missing values (visits) were not included in analysis and the last observation was carried forwards. Data after switching of immunosuppressant of interest till the last follow up visit was analysed descriptively. All analysis were done for matched and unmatched patient groups. The results of matched and unmatched cohort were similar, hence the results of unmatched groups are presented here.

Results

Overall, 234 patients satisfying inclusion criteria including 53 (22.6%), 156 (66.7%) and 25 (10.7%) patients receiving AZA, MMF, Mtx respectively were studied. Complete remission (CR) was attained in 183 (78.2%) patients after initiating steroids and IS. 79.2%, 77.6% and 80% of patients receiving AZA, MMF or MTX respectively achieved CR yielding an odds ratio of 1.10 (0.52-2.37), p= 0.80 and 0.96 (0.29-3.12), p= 0.94 for MMF and MTX as compared with AZA. CR was sustained in 22 (52.4%), 80 (66.1%) and 11 (55%) of patients on AZA, MMF and MTX respectively. When compared with AZA, adjusted hazards ratio (AHR) of relapse was 1.51 (0.79-2.89), p=0.21 and 2.45 (1.00-5.99), p= 0.05 with MMF and MTX after adjusting for juvenile onset disease, type 1 and type 4 disease by angiography. The frequency of remission in patients who received MMF was significantly higher in patients who presented with type 4 disease (96%) as compared with the patients who had other types on angiography (74%), p= 0.017. Conversely, 63.6% of patients with type 1 disease responded to MMF which was significantly lower than 81.3% of patients with other angiographic types (p=0.037) while no such differential response was observed for AZA or MTX. Retrospective design and small number of patients in AZA and Mtx group were the major limitations of the study.

Conclusion

In our patients with TAK, all the three IS were comparable in inducing remission. Azathioprine was equal to MMF but superior to MTX in maintaining relapse free sustained response. The efficacy of MMF differed across various angiographic types of disease.

References

None

Disclosure of Interests

None declared

Concurrent T790M and L858R mutations in treatment-naïve metastatic non-small-cell lung cancer: A therapeutic challenge – Current treatment strategies and promising therapies of the future in a nutshell

De novo (pretreatment) epidermal growth factor receptor T790M mutation in non-small-cell lung cancer (NSCLC) is rare when detected by standard genotyping methods. We present a case of concurrent de novo T790M and L858R mutations detected by direct sequencing in treatment-naïve metastatic NSCLC. This case is worthy of mention as the presence of this mutation has a bearing on the choice of treatment. This article aims to evaluate the clinical outcome for metastatic NSCLC with de novo T790M mutation and formulate an optimum treatment plan in this clinical scenario. The novel targeted therapy agents have also been reviewed.

A Rare Survival in Celphos Poisoning

Aluminium phosphide poisoning releases phosphine gas which causes inhibition of cytochrome oxidase, inhibition of electron transport chain and thereby myocardial suppression. It is known to cause various electric abnormalities in the heart from ST-T depression to fatal tachyarrhythmias. Here we present a case of celphos poisoning presenting with both supraventricular tachycardia and ventricular tachycardia.

Medical Image Reliability Verification Using Hash Signatures and Sequential Square Encoding

Increased growth of information technology in healthcare has led to a situation where the security of patient information is more important and is a critical issue. The aim of the proposed algorithm is to provide a framework to verify the integrity of the medical images. In this paper, the integrity of the medical images is verified by embedding hash signatures using the sequential square embedding technique. This technique is as efficient as the diamond encoding technique but with increased payload capability. The medical image is first divided into the region of interest (ROI) block and the signature block. The hash signatures are determined by dividing the ROI into nonoverlapping blocks. During the data hiding stage, the hash signatures are embedded in randomly chosen pixel pairs in the signature block using the sequential square encoding (SSE) technique. In the experimental results, the data hiding capacity of the proposed SSE technique is verified in terms of peak signal-to-noise ratio. Also, the medical image integrity is substantiated by comparing the L2 norm between computed and extracted hash signatures. Modifications such as contrast enhancement, rotation, scaling, and changing the image information result in increased L2 norm; thus, the integrity of the medical images can be verified. The parameters required for embedding, such as the embedding parameter and the seed for random sequence generation, are encrypted and communicated to the receiving end. Hence, the proposed algorithm provides a secure framework for medical image integrity verification.

Study on biofilm formation in burn wound infection in a pediatric hospital in Chennai, India

Infection is one of the major causes of death in pediatric burns in India. This work was conducted in an exclusive Children's Hospital (KKCTH) with a total of 220 beds, of which ten beds in the burn unit and two isolation beds in the 28-bed PICU are for burns patients (more than 20% TBSA burns) with sepsis. In this study, 30 burn wound swab isolates obtained from 14 pediatric burns patients (admitted to the burns ward and transferred to PICU) from November 2013 to March 2014 were investigated. Cultures were done on the first day for all patients and empirical antibiotic administration was started for those with septic burns (14 in total) with piperacillin-tazobactam and vancomycin. Antibiotics were changed according to antibiotic sensitivity reports. Cultures were repeated for culture positive cases on the fifth day. Further antibiotic treatment was based on this culture report. When the general condition of the patient did not respond to highlevel antibiotics, biofilm formation was suspected and evaluated as the possible cause of antibiotic resistance. For these patients, an enhanced method of wound debridement and albumin transfusions were used to improve their general condition. Microbial identification and antimicrobial sensitivity testing was done for all 30 isolates. The predominant bacteria were Pseudomonas aeruginosa, Acinetobacter and Staphylococcus aureus. Most of the Acinetobacter and Staphylococcus aureus showed multidrug resistance. Biofilm formation was studied using the Tissue Culture Plate (TCP) method for all bacterial isolates, and results showed that most of the MDR isolates formed biofilm.

Response of keloid fibroblasts to Vitamin D3 and quercetin treatment - in vitro study

Keloid scars continue to pose a challenge to clinicians as the treatment armamentarium lacks a formidable agent to tackle them. We have undertaken an in vitro study based on the mechanism of action of Vitamin D3 and quercetin on isolated keloid fibroblasts. Dose-dependent action on the reduction of cellular proliferation, collagen synthesis and induction of apoptosis by Vitamin D3 and quercetin are analyzed and probable mechanism of action is elaborated. This study thus opens up newer avenues in tackling keloid scars effectively.

High voltage electrical burn injuries in teenage children: case studies with similarities (an Indian perspective)

From 1992 to 2012, a total of 911 paediatric burns were admitted and treated at Kanchi Kamakoti Childs Trust Hospital Intensive Burn Care Unit, of these 28 children had suffered electrical injuries and burns. 7 teenagers suffered high voltage electrical burn injuries: 2 were involved in train accidents which caused fatal electrical injuries, and 5 had electrical burn injuries caused by similar types of accidents, requiring Paediatric Intensive Care Unit (PICU) care, repeated surgeries and extensive rehabilitation. A common factor among these latter 5 patients was that they were injured by overhead high electrical voltage cables. Their management was labour intensive and highly costly. In this report, the type of accident, the electrical voltage that produced burns and the treatment details are elaborated. Findings included similarities in age and type of accident, and failure to implement safety procedures and apply standard norms of high voltage transmission feeder lines.

Advantages of collagen based biological dressings in the management of superficial and superficial partial thickness burns in children

Collagen based dressings for acute burn wound management have been extensively used in India, particularly in the city of Chennai. Due to the high levels of humidity in our city, closed dressings become infected and treatment with topical antimicrobials, like Silver Sulfadiazine cream, quickly become desiccated. Collagen membrane dressings were manufactured by the biomaterial laboratory of the Central Leather Research Institute (CLRI), Government of India in Chennai, and then the process was patented. Collagen was extracted from bovine skin and Achilles tendons, and then reconstituted. This was used on burn wounds as dressings after clearance from the Institutional Review Board and Ethics Committees of the Hospital and CLRI. Continued research in this field to enable resulted in the design of silver sulphadiazine loaded alginate microspheres which were embedded in the reconstituted collagen. Controlled delivery of silver sulphadiazine. This collagen membrane was used in chronic infected burns. Low molecular weight heparin was given subcutaneously to improve wound healing in burn injuries and collagen membrane dressings were also applied. After several trials the process technology was patented. The advantages and disadvantages of the collagen membrane cover is elaborated in a group of 487 pediatric burn patients. The trial was conducted at the burn unit of Kanchi Kamakoti Childs Trust Hospital (KKCTH) in Chennai, India.

Expression of fibrocyte markers by keloid fibroblasts: an insight into fibrosis during burn wound healing - a preliminary study

In extensive burns it becomes difficult for fibroblasts to migrate from the periphery of the healthy tissue and colonize the injured area. Even under such circumstances healing takes place, and this is attributed to the differentiation of circulating fibrocytes which enter the wound site. This normal cell type is identified in keloid fibroblasts: it expresses fibrocyte markers and secretes extra cellular matrix proteins. In-vitro collagen contraction assay reveals that fibrocytes contract collagen gels with an efficacy similar to normal fibroblasts. The contribution of fibrocytes to the formation of keloid fibroblasts in post-burn healing is discussed.

2,3-Dibromo-3-(4-chloro-phen-yl)-1-(4-nitro-thio-phen-2-yl)propan-1-one

The title compound, C(13)H(8)Br(2)ClNO(3)S, exhibits whole-mol-ecule disorder over two orientations in a 0.805 (6):0.195 (6) ratio. The dihedral angles between the thio-phene ring [maximum deviations = 0.017 (4) and 0.033 (9) Å for the major and minor components, respectively] and the chloro-substituted phenyl ring are 32.1 (5) (major component) and 26.3 (18)° (minor component). In the crystal, C-H⋯Cl and C-H⋯O hydrogen bonds link the mol-ecules into sheets lying parallel to the bc plane. Aromatic π-π stacking inter-actions [centroid-centroid distance = 3.550 (7) Å] are also observed.

(E)-N′-(4-Chlorobenzylidene)-1-benzofuran-2-carbohydrazide monohydrate

The title compound, C₁₆H₁₁ClN₂O₂·H₂O, exists in an E conformation with respect to the N=C bond. The benzofuran ring system forms a dihedral angle of 1.26 (4)° with the benzene ring. In the crystal, mol­ecules are linked via (N,C)—H⋯O bifurcated acceptor hydrogen bonds and (O,O,C)—H⋯O trifurcated acceptor hydrogen bonds, forming layers parallel to the bc plane.

3-Methyl-4-[2-(4-nitro-phen-yl)hydrazin-1-yl-idene]-5-oxo-4,5-dihydro-1H-pyrazole-1-carbothio-amide

The asymmetric unit of the title compound, C(11)H(10)N(6)O(3)S, contains two independent mol-ecules, each of which is stabilized by an intra-molecular N-H⋯O hydrogen bond, forming an S(6) ring motif. In one mol-ecule, the pyrazole ring forms a dihedral angle of 10.93 (14)° with the benzene ring. The corresponding dihedral angle in the other mol-ecule is 7.03 (14)°. In the crystal, mol-ecules are linked via pairs of (N,N)-H⋯O bifurcated acceptor bonds which, together with C-H⋯O hydrogen bonds, form sheets parallel to (001).

N'-[(E)-4-Bromo-benzyl-idene]-1-benzofuran-2-carbohydrazide monohydrate

The title compound, C₁₆H₁₁BrN₂O₂·H₂O, exists in a trans conformation with respect to the N=C bond [1.2815 (14) Å] and the benzofuran ring system forms a dihedral angle of 2.96 (5)° with the benzene ring. In the crystal, the ketone O atom accepts two O—H⋯O and one C—H⋯O hydrogen bond, and the water O atom accepts an N—H⋯O inter­action. Together, these lead to infinite layers lying parallel to (100).

Current scenario in chemical burns in a developing country: Chennai, India

Chemical burns are not uncommon in India. Both accidental and non-accidental chemical burns are encountered in our setting. In the paediatric age group, chemical burns are mainly accidental. Analysis of chemical burn admissions to the Burn Units of a medical college hospital, and to an exclusively tertiary care children's hospital in Chennai, India, from 2001 to 2010 is described. A total number of 75 adults and 38 children are included in the study. Detailed analysis of age, sex, percentage of burn total body surface area (TBSA %), causative agents, aetiology (accidental or non-accidental), treatment instituted, mortality, and outcome are reported.

Profile of burn sepsis challenges and outcome in an exclusive children's hospital in Chennai, India

A group of 273 paediatric patients admitted to Kanchi Kamakoti Childs Trust Hospital Burn Unit, Chennai, India between the years 2004 to 2010 were analysed retrospectively. Of these, 89 were suffering from sepsis and septic shock and 15 died. Strict adherence to antibiotic administration and to the Paediatric Intensive Care Unit (PICU) and management protocol improved the outcome, especially in 2009 and 2010.

Low molecular weight heparin mediated regulation of nitric oxide synthase during burn wound healing

Nitric oxide (NO) is an important signal molecule in many types of cells and tissues. Efficiently balanced NO production was noted to play an important role in the healing of burns. Inducible nitric oxygen synthase (iNOS) is responsible for the discontinuous synthesis of high amounts of NO. Dysregulation of nitric oxygen synthase (NOS) activity has been associated with multiple organ failure in burn patients and may therefore represent a novel therapeutic target in such circumstances. Heparin and low molecular weight heparin (LMWH) derivatives may offer therapeutic benefit for inflammatory diseases, whereas NO plays a protagonist role. Burn injury in humans has been associated with a significant increase in NO(2)/NO(3) (nitrite/nitrate) plasma levels. In this prospective study burn patients were treated with and without LMWH to provide evidence that LMWH has NOS-reducing activity. This was proved by colorimetric and immunohistological studies. There was a significantly different NOS activity between the treated and the control group and our results suggest that LMWH was more effective in the treatment of burn patients through iNOS inhibition. Treatment with LMWH was initiated within 6 h post-burn.

2,2'-Dithio-dianiline: a redetermination at 100 K

Structural studies of the title compound [systematic name: 2,2′-(disulfanedi­yl)dianiline], C₁₂H₁₂N₂S₂, were previously performed at room temperature [Gomes de Mesquita (1967 ▶). Acta Cryst.23, 671; Lee & Bryant (1970 ▶). Acta Cryst. B26, 1729; Ribar et al. (1975 ▶). Bull. Yugoslav. Crystallogr. Centre, A10, 68]. The results of the current redetermination allow a clarification of the nature of the intra- and inter­molecular N—H⋯S hydrogen bonding described in the literature for this compound. On cooling to 100 K, the unit cell contracts most in the c axis, and it changes rather less in the directions involving the strongly hydrogen-bonded chains, which are the a and b axes. In the crystal structure, N—H⋯N hydrogen bonds link neighbouring mol­ecules into two-dimensional frameworks parallel to the ab plane. An additional inter­molecular N—H⋯S hydrogen bond has also been established, based on freely refined H-atom positions. Inter­molecular C—H⋯π inter­actions further stabilize the crystal structure.

Ethyl 4-[3,5-bis-(trifluoro-meth-yl)phen-yl]-6-methyl-2-oxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

In the title compound, C₁₆H₁₄F₆N₂O₃, the dihydro­pyrimid­in­one ring adopts an envelope conformation. In the crystal, mol­ecules are linked by N—H⋯O and C—H⋯O hydrogen bonds into a ribbon-like structure along the b axis. In the ribbon, a pair of bifurcated acceptor N—H⋯O and C—H⋯O bonds generate an R₂¹(6) ring motif. Adjacent ribbons are linked via C—H⋯F hydrogen bonds.

Ethyl 4-(2,4-difluoro-phen-yl)-6-methyl-2-oxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

In the title compound, C₁₄H₁₄F₂N₂O₃, the dihydro­pyrimidin­one ring adopts a flattened boat conformation. The difluoro­phenyl group is disordered over two orientations with occupancies of 0.544 (3) and 0.456 (3). The methoxy­carbonyl group is disordered over two positions with occupancies of 0.580 (8) and 0.420 (8). In the crystal, mol­ecules are linked into centrosymmetric dimers by paired N—H⋯O hydrogen bonds and the dimers are linked into a ribbon-like structure along [100] by further N—H⋯O hydrogen bonds.

Ethyl 4-(2,4-difluoro-phen-yl)-6-methyl-1-phenyl-2-thioxo-1,2,3,4-tetra-hydro-pyrimidine-5-carboxyl-ate

The asymmetric unit of the title compound, C₂₀H₁₈F₂N₂O₂S, contains four independent mol­ecules, two of which are paired into a dimer by way of two N—H⋯S hydrogen bonds. The other two independent mol­ecules are paired into two centrosymmetric dimers via pairs of inter­molecular N—H⋯S hydrogen bonds. In one mol­ecule, the carboxyl­ate O atoms, methyl­ene and methyl groups attached to the benzene ring are disordered between two positions in a 0.908 (3):0.092 (3) ratio. In two of the independent mol­ecules, the F and H atoms of the diflourophenyl ring are flip-flop disordered (i.e. by 180° about the C—C bond axis linking the ring to the rest of the molecule) in a 3:2 ratio. The crystal packing is stabilized by weak inter­molecular C—H⋯O hydrogen bonds.

A molecular method for typing Herpes simplex virus isolates as an alternative to immunofluorescence methods

BACKGROUND

Typing of Herpes simplex virus (HSV) isolates is required to identify the virus isolated in culture. The methods available for this include antigen detection by immunofluorescence (IF) assays and polymerase chain reaction (PCR). This study was undertaken to standardize a molecular method for typing of HSV and compare it with a commercial IF reagent for typing.

OBJECTIVES

To compare a molecular method for typing HSV isolates with a monoclonal antibody (MAb) based IF test.

STUDY DESIGN

This cross-sectional study utilized four reference strains and 42 HSV isolates obtained from patients between September 1998 and September 2004. These were subjected to testing using an MAb-based IF test and a PCR that detects the polymerase ( pol ) gene of HSV isolates.

RESULTS

The observed agreement of the MAb IF assay with the pol PCR was 95.7%. Fifty four point eight percent (23/42) of isolates tested by IF typing were found to be HSV-1, 40.5% (17/42) were HSV-2, and two (4.8%) were untypable using the MAb IF assay. The two untypable isolates were found to be HSV-2 using the pol PCR. In addition, the cost per PCR test for typing is estimated to be around Rs 1,300 (USD 30), whereas the cost per MAb IF test is about Rs 1,500 (USD 35) including all overheads (reagents, instruments, personnel time, and consumables).

CONCLUSION

The pol PCR is a cheaper and more easily reproducible method for typing HSV isolates as compared to the IF test. It could replace the IF-based method for routine typing of HSV isolates as availability of PCR machines (thermal cyclers) is now more widespread than fluorescence microscopes in a country like India.

SEM and raman spectroscopy of multiwalled carbon nanotubes grown by novel technique of ash supported catalysts

Multiwalled carbon nanotubes (MWCNTs) were grown on a novel ASC catalyst and on catalyst deposited by SCC method on silicon wafer, by thermal CVD of acetylene. Fe and Ni were used as catalyst for ASC. Samples were analyzed by SEM and Raman spectroscopy. SEM analysis shows that CNTs grown on ASC have narrower diameter distribution (64+/-6 nm) compared to CNTs grown on SCC (67+/-10.5 nm). However, SEM and Raman spectroscopy studies show CNTs grown on SCC are of better quality. The same samples were studied after standard purification procedure of oxidation after annealing at high temperatures. SEM and Raman spectroscopy show that overall quality of ensemble of CNTs has improved. After annealing, diameter decreases for larger diameter approximately 200 nm nanotubes while it increases for CNTs of smaller diameter approximately 70 nm. To explain the increase in diameter of approximately 70 nm CNT's, a phenomenological model has been proposed. The results of Raman spectroscopy and SEM corroborate the proposed model.

Low molecular weight heparin-induced pharmacological modulation of burn wound healing

Low molecular weight heparin (LMWH) appears to be a promising solution for reducing inflammatory post-burn episodes and results in improved healing. The clinical examination presented here includes patients with burn wounds ranging from 20 to 35% total body surface area (TBSA) who were categorized into two groups, of which one received subcutaneous LMWH treatment (10,000 units/day) and the other acted as control. The process of healing was assessed through regular examination of clinical features such as regression of erythema and oedema, eschar formation, and rate of re-epithelialization. Various studies have demonstrated an increase in levels of serum IL-6 indicating the severity of the morbid condition. In the present investigation, LMWH-treated patients exhibited a faster decline in levels of serum IL-6 (within 12 days) than control. Infiltration of inflammatory cells at the local wound site was assessed through a histological analysis of tissue samples taken on various days during the healing process. The LMWH-treated groups exhibited an organized healing pattern with better remodelling in a shorter duration (28 days), while control patients took more than 28 days for complete healing. A slight correlation was observed with TBSA to the inflammatory process, which subsided in patients treated with LMWH, favourably modulating the events involved in the inflammatory process of burn wound healing.

Effect of total colectomy and PYY infusion on food intake and body weight in rats

PYY (3-36) is postulated to act as a satiety factor in the gut-hypothalamic pathway to inhibit food intake and body weight gain in humans and rodent models. We determined the effect of 14-day continuous intravenous infusion of PYY (3-36) (175 microg/kg/day) on food intake and body weight gain in colectomized male Wistar rats. Colectomy caused an increase in plasma PYY levels at 7 days which was reduced at 14 days but still significantly elevated compared to basal preoperative values. Animals treated with continuous PYY (3-36) infusion had significantly elevated PYY levels compared to the control group throughout the whole experiment, but showed a similar pattern of food intake and body weight gain. In conclusion, although continuous intravenous infusion is the most physiologically relevant method to mimic high postprandial PYY levels, we did not observe any significant effect on food intake and body weight gain in non-food deprived colectomized animals. This suggests that PYY has, if at all, only a minor role in food intake in rats.

Ultrastructural differentiation of abnormal scars

AIM

To evaluate the differences between keloid and hypertrophic scars by biochemical and ultrastructural techniques.

METHOD

Over 1000 patients with different types of scars were studied and followed up for a period of 20 years. The histochemical and biochemical analysis with respect to the composition of the extracellular matrix of the dermis was conducted. At the ultrastructural level, collagen deposition and assembly were studied using electron microscopy. The rate of proliferation and metabolic activity of the dermal fibroblasts isolated from the normal skin and scar biopsies were studied to assess the cause of excess matrix deposition in scar tissues.

RESULTS

Evaluation of different types of scars showed that both keloid and hypertrophic scars have excess matrix deposition in terms of collagen and proteoglycans. Keloid shows a high amount of acid-soluble collagen. The assembly of collagen fibrils is also abnormal in keloids. Studies on the proliferation and metabolic activity showed that keloid fibroblasts have a higher rate of proliferation and metabolic activity than fibroblasts from hypertrophic scars and normal skin. Finally, keloid fibroblasts show high and intense staining for the endoplasmic reticulum, suggesting a possible reason for high activity of these fibroblasts.

CONCLUSION

Keloids and hypertrophic scars show distinct ultrastructural patterns of both collagen deposition and assembly. These parameters could be refined by further research, and they would thus serve as a useful tool for surgeons to distinguish different types of scars and adopt suitable therapeutic strategies.

Genetic analysis of primary microcephaly in Indian families: novel ASPM mutations

Patients with primary microcephaly, an autosomal recessive trait, have mild to severe mental retardation without any other neurological deficits. It is a genetically heterogeneous disorder with six known loci: MCPH1 to MCPH6. Only the genes for MCPH1 and MCPH5 have been identified so far. We have ascertained nine consanguineous families with primary microcephaly from India. To establish linkage of these nine families to known MCPH loci, microsatellite markers were selected from the candidate regions of each of the six known MCPH loci and used to genotype the families. The results were suggestive of linkage of three families to the MCPH5 locus and one family to the MCPH2 locus. The remaining five families were not linked to any of the known loci. DNA-sequence analysis identified one known (Arg117X) and two novel (Trp1326X and Gln3060X) mutations in the three MCPH5-linked families in a homozygous state. Three novel normal population variants (i.e., c.7605G > A, c.4449G > A, and c.5961 A > G) were also detected in the ASPM gene.

Biocompatible collagen scaffolds from a human amniotic membrane: physicochemical and in vitro culture characteristics

A reconstituted collagen membrane from human amnion has been investigated as a source of collagen matrix, which could be used as a substratum for culturing human fibroblasts. The suitability of pepsin-solubilized reconstituted human amniotic membrane, before and after cross-linking with chitosan, as a dermal matrix for culturing fibroblast was assessed by morphologic, physicochemical, cytotoxic and histochemical methods. Measurement of thermodynamic behaviour, by differential scanning calorimetric (DSC) and thermogravimetric analysis (TGA), and tensile strength suggested that the cross-linked membrane had sufficient elasticity to serve as an efficient dermal substrate for in vitro culture of fibroblasts. Fibroblasts cultured on the chitosan cross-linked collagen membrane had good adherence, retaining their morphology as indicated by microscopic analysis. Proliferation of fibroblasts. observed on this membrane affirms its non-toxic nature. These results support the application of reconstituted human amniotic collagen membrane as collagenous scaffolds to culture fibroblasts in vitro.

Application of frog (Rana tigerina Daudin) skin collagen as a novel substrate in cell culture

Collagen and collagen-based materials have extensive application in biomedical devices and tissue engineering. The current paper pertains to the application of frog (Rana tigerina Daudin) skin collagen as a novel substrate in cell culture. The study deals with the behavior, morphology, and physiology of keratinocytes and fibroblasts over dry and reconstituted collagen substratum, which are the key cells involved in wound repair. The advantage of using frog skin collagen as a substratum lies in the ease with which the reconstituted gel can be formed. Further, frog skin collagen is highly hydrophilic, which may be attributed to the fact that amphibians, as the first vertebrates connecting water and land, must have evolved certain physiologic specializations. These studies also contribute to the hypothesis that part of the healing efficacy of frog skin may be due to the collagen since proliferation, migration, and differentiation of epithelial cells are prime requisites for a normal healing mechanism.

Effect of trypsin-chymotrypsin (Chymoral Forte D.S.) preparation on the modulation of cytokine levels in burn patients

The present study was carried out in burn patients administered with Trypsin-Chymotrypsin (Chymoral Forte D.S.) preparation to observe if the acute-phase protein levels in the serum are modulated through the synthesis of IL-1beta and IL-6 and if the severity of the inflammatory phase could be regulated. The effects of Trypsin-Chymotrypsin preparation on the modulation of cytokine levels particularly, IL-6 and IL-1beta were analyzed in serum samples of 15 burn patients and compared with untreated controls. Significant differences in cytokine levels (P<0.05) were observed in untreated burn patients and Trypsin-Chymotrypsin preparation treated patients. There were significant variations in serum IL-6 and IL-1beta on the day of admission and post burn day 10 in treated as well as untreated burn patients. Patients with a higher percentage of total body surface area and sepsis showed a significant increase in IL-1beta and IL-6 in the serum. An increase in serum levels of both cytokines was observed on post burn day 1 and a significant decrease was observed in Trypsin-Chymotrypsin preparation treated patients on days 7 and 10. The possible role of the inflammatory cytokines in the pathophysiology of burns is discussed.

Studies on Rana tigerina skin collagen

The current paper pertains to the study of frog skin, more specifically Rana tigerina skin collagen, which is a major extracellular matrix protein known to play an important role in the wound-healing process. This study revealed interesting differences in the frog skin collagen when compared to the hitherto known vertebrate collagens. This could probably be attributed to the position of the amphibians in the vertebrate hierarchy. Therefore, detailed investigations on the various physico-chemical properties, such as reconstitution, redissolution, viscosity and denaturation were carried out. The study confirms the structural relationship of collagen to habitat and function.