Gastrointestinal: gastric wall hematoma.
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Hematoma↗
Biomedical subjects
D Datta
Publications and source records attributed to D Datta.
Gait, cost and time implications for changing from PTB to ICEX sockets.
The ICEX system (Ossur, Iceland), allows a socket to be manufactured directly onto the stump and is thought to provide improved comfort due to better pressure distribution whilst being easier to fit and manufacture. The aims of this project were to a) compare gait performance by measuring several gait characteristics, b) compare production and fitting times, c) investigate financial implications and d) attempt to gauge the amputees' subjective opinions of socket comfort. A randomised, controlled trial was conducted on 27 trans-tibial amputees with an existing patellar tendon bearing (PTB) socket on the Endolite system (Chas A. Blatchford, UK). Twenty one (21) subjects completed the study. Of these, 10 in the control group received new PTB sockets while 11 in the experimental group received ICEX. Gait analysis wearing existing sockets was performed and kinetic data obtained from a force plate. This was repeated with the new sockets after a 6 week period of adjustment. Mann-Whitney tests were used in statistical evaluations with a significance level of 5%. Subjects were asked to score their prosthesis for comfort using the Socket Comfort Score (Hanspal et al., 2003) and the frequency of visits for socket adjustments over a three-month period post-delivery of the sockets was recorded. This study demonstrates no significant difference in any of the gait parameters measured. Though the time required to manufacture a PTB prosthesis was found to be considerably longer than the ICEX, the overall cost for producing the ICEX was significantly greater. Subjects showed only minor comfort preference for the ICEX design and there was no significant difference in the mean number of visits for socket adjustments. In view of the considerable additional cost of providing ICEX and the lack of evidence of improvement in any parameter tested, the routine provision of ICEX prostheses to unselected trans-tibial amputees cannot be recommended.
Adolescent↗
High versus low intensity exercise training in pulmonary rehabilitation: is more better?
BACKGROUND: Exercise training is considered a necessary component of comprehensive pulmonary rehabilitation. However, to date, there is no consensus on an exercise training strategy for pulmonary rehabilitation, and this has resulted in varied approaches to this intervention in its literature. As in healthy individuals, the effect of exercise training on patients with chronic lung disease is dose dependent, with higher intensities resulting in greater physiological adaptations than lower intensities. RESULTS: It is not clear from our review of the literature that these enhanced physiological effects from higher levels of exercise training translate into a reduced burden of symptoms, hence a better quality of life. Indeed, there is some evidence that pulmonary rehabilitation approaches incorporating lower intensities of exercise training are at least as good in improving questionnaire rated symptoms of health status. This provides food for thought, since the prominent goal of pulmonary rehabilitation should be to reduce bothersome symptoms or enhance health status, not simply increase endurance time on a cycle ergometer.
Exercise Therapy↗
Role of L-lysine HCl in adoptive immune therapy towards development of suitable tuberculosis vaccination.
L-Lysine HCI is being proposed to be a possible biocompatible adjuvant to enhance immune response by virtue of its probable non-specific bridging action and cellular proliferation properties. This proposal has been tried to be substantiated by designing an in vitro culture protocol, varying the concentration of L-lysine HCI and its further in vivo application. Splenic lymphocyte population has been extracted from mice and co-cultured with extracted mice macrophage population in presence of either Bacille Calmette Guerrin (BCG) or Hepatitis B surface antigen (HbsAg) and added L-lysine hydrochloride in culture media. Post incubation of these cultures, "taught" cell population has been adoptively transferred in naïve mice. These mice were then challenged by respective antigen dose, Change in Immune response with this challenge was noted. Antibody titre was followed in all the experiments as a measure of immune response. In adoptive immune transfer experiment of with HbsAg (AIT-HbsAg), similar to that with BCG (AIT-BCG), after the incubation period, antibody titre was higher in added lysine containing cultures in comparison with the control ones. Post transfer followed by antigen challenge, in AIT-BCG the expected augmentation in immune response was hardly visible. But in AIT-HbsAg, with the help of lysine booster, the animals responded better as far as the antibody titre is concerned.
Animals↗
Role of L-lysine HCl in immunopotentiation towards development of suitable tuberculosis vaccination.
L-Lysine HCl is being proposed to be a possible biocompatible adjuvant to enhance immune response by virtue of its probable non-specific bridging action and cellular proliferation properties. This proposal has been tried to be substantiated by carrying out experimentation where L-lysine HCl has been used as an adjuvant (various groups based on mode of application and frequency of booster dose were designed) in tuberculosis vaccination experiments with heat killed Mycobacterium tuberculosis (MTB) and Bacille Calmette Guerin (BCG). Antibody titre has been followed in all the experiments as a measure of immune response. Amongst the various groups designed, group 1A (L-lysine HCl was given at a separate site as that of the antigen; lysine booster was given to this group intermittently, i.e. lysine given on 0th, 7th, 14th, 21st days of immunization) came out as the stand-alone leader. This mode and frequency of application was then compared with a group which received a standard adjuvant, viz. alhydrogel. Results were obtained which showed the following order in terms of decreasing antibody titre: alhydrogel group > lysine group > control group. Considering the biocompatible nature of lysine in comparison with the reportedly hazardous nature of alum adjuvants, we propose L-lysine HCl as a probable adjuvant in vaccination.
Adjuvants, Immunologic↗
Matched case-control study to evaluate risk factors for hyperlactataemia in HIV patients on antiretroviral therapy.
BACKGROUND: Lactic acidosis is a life-threatening event during antiretroviral therapy (ART). Hyperlactataemia may be a prelude to acidosis. Our database study suggested that female gender, intercurrent illness and didanosine (ddI)-based regimens may increase risk of lactic acidosis. The aim of this matched case-control study was to identify risk factors for hyperlactataemia requiring screening. METHODS: Cases were defined as patients with two consecutive lactate samples > or =3.5 mmol/L taken more than 1 week apart. Cases were matched to two controls on gender, use of ddI and total duration of therapy using a 6-month window on either side. Controls never had raised lactate >2.5 mmol/L. A conditional logistic regression analysis using the PHREG procedure in SAS (SAS Institute Inc, Cary, NC) was performed with a discreet logistic model stratified by matching variables. RESULTS: Twenty-one cases were matched to 42 controls. In the univariate model, current use of stavudine (d4T), total cholesterol >5.3 mmol/L and glucose levels > or =5.2 mmol/L gave increased likelihood of persistent hyperlactataemia. The multivariate model showed current use of d4T to be a significant independent predictor of persistent hyperlactataemia. CONCLUSIONS: The results of this case-control study indicate that, when controlling for ddI use, d4T use is an additional risk factor for hyperlactataemia.
Acidosis, Lactic↗
Use of fibrin glue (beriplast) in the management of bleeding gastric varices.
BACKGROUND AND AIMS: Gastric variceal bleeding is a serious complication of portal hypertension. The optimum endoscopic treatment of bleeding gastric varices is yet to be defined. We evaluated the use of Beriplast, which is a solution of fibrinogen and thrombin, in controlling gastric variceal bleeding. PATIENTS AND METHODS: Fifteen patients presenting with gastric variceal bleeding were entered into an open trial of endoscopic gastric intravariceal injection treatment with Beriplast (fibrin sealant) and followed for up to 1 month after endoscopic treatment. RESULTS: There was failure to control bleeding in one patient. Four patients had rebleeding after the index bleed. All four were reinjected with Beriplast, and the bleeding was controlled in three. All patients were followed for 30 days, and the 30-day mortality following injection treatment was one. Fourteen patients were discharged from the hospital after the first episode of gastric variceal bleeding. None of the patients had injection-induced complications. CONCLUSIONS: These results show that Beriplast is a safe and simple endoscopic treatment option and is very effective in controlling gastric variceal bleeding.
Adolescent↗
Mobility outcome following unilateral lower limb amputation.
This study investigated mobility outcome following unilateral trans-tibial or trans-femoral amputation. It was an observational study at the sub-regional amputee rehabilitation centre in Sheffield, UK. All unilateral trans-tibial or transfemoral amputees referred during the study period were included. The Harold Wood Stanmore mobility grade was recorded approximately one year following initial assessment at the centre. Of the 357 amputees referred, complete outcome data was available for 281 (78.7%). The mean age was 68 years (range 16-95), 70.1% were male, and the aetiology of the amputation was vascular or diabetic in 87.5% of cases. Trans-tibial amputations accounted for 50.5% and trans-femoral 49.5%. Almost all trans-tibial and trans-femoral amputees aged 50 and under achieved functional household and community mobility. Approximately 50% of the trans-tibial amputees aged over 50 years gained independent community mobility and around 60% household mobility. There was a significant worsening of community mobility rates with increasing age but for household mobility the differences did not reach statistical significance. Fewer than 25% of trans-femoral amputees aged over 50 achieved community mobility and around 50% achieved household mobility. There was a statistically significant deterioration in both community and household mobility levels with increasing age. This study concludes that mobility rates one year after prosthetic provision for unilateral trans-tibial and trans-femoral amputees worsen with increasing age at amputation and a higher level of amputation.
Adolescent↗
Investigation on Tc tuned nano particles of magnetic oxides for hyperthermia applications.
Superparamagnetic as well as fine ferrimagnetic particles such as Fe3O4, have been extensively used in magnetic field induced localized hyperthermia for the treatment of cancer. The magnetic materials with Curie temperature (Tc) between 42 and 50 degrees C, with sufficient biocompatibility are the best candidates for effective treatment such that during therapy it acts as in vivo temperature control switch and thus over heating could be avoided. Ultrafine particles of substituted ferrite Co(1-a)Zn(a)Fe2O4 and substituted yttrium-iron garnet Y3Fe(5-x)Al(x)O12 have been prepared through microwave refluxing and citrate-gel route respectively. Single-phase compounds were obtained with particle size below 100 nm. In order to make these magnetic nano particles biocompatible, we have attempted to coat these above said composition by alumina. The coating of alumina was done by hydrolysis method. The coating of hydrous aluminium oxide has been done over the magnetic particles by aging the preformed solid particles in the solution of aluminium sulfate and formamide at elevated temperatures. In vitro study is carried out to verify the innocuousness of coated materials towards cells. In vitro biocompatibility study has been carried out by cell culture method for a period of three days using human WBC cell lines. Study of cell counts and SEM images indicates the cells viability/growth. The in vitro experiments show that the coated materials are biocompatible.
Aluminum Oxide↗
An unusual complication of a myoelectric prosthesis.
This clinical note describes an unusual and previously unreported complication of wearing a myoelectric prosthesis in a child with congenital upper limb deficiency. After an initial period of wearing a cosmetic prosthesis, he was provided with a child's trans-radial myoelectric prosthesis with a Steeper Scamp Electric hand at the age of 21 months. After successful and uncomplicated use of this prosthesis for 2 years--a sudden onset of burns of the skin of the stump underlying the single electrode site was noted. The cause of the burns was thought to be due to heat generated from electrical failure possibly from ingress of moisture. This complication has not before been experienced in the authors' centre, nor has it been reported in the literature. While constant improvements are being made in the field of electrically powered prosthesis, the rehabilitation team should be aware of this unusual complication.
Amputation Stumps↗
Effect of addition of proton carriers in culture medium on growth and secretion of hybridoma cell line OKT3.
Monoclonal antibodies (MAb) constitute the centre of all in-vitro diagnostic measures and almost all in-vivo therapeutic manoeuvres now. Production emphasis for these antibodies is having a current shift from animal-based large-scale culture to in-vitro bioreactor-based high-density culture. One of the major difficulties in high-density culture is end-metabolite accumulation in batch and fed-batch cultures in the forms of H+, NH4+ etc.. thereby reducing cellular growth and secretions. In the present study, effects of added proton carries--NAD and NADP--over and above the metabolic pools of the molecules, were examined on the cellular growth and secretion kinetics. Although NADP fortification showed a remarkable improvement in cellular growth (time dependent 200-300% improvements compared to controls) and size, cumulative MAb titre was better with NAD fortification. Combined additional loads of the proton carriers would be interesting to study in high density culture conditions.
Algorithms↗
Designing protein beta-sheet surfaces by Z-score optimization.
Studies of lattice models of proteins have suggested that the appropriate energy expression for protein design may include nonthermodynamic terms to accommodate negative design concerns. One method, developed in lattice model studies, maximizes a quantity known as the " Z-score," which compares the lowest energy sequence whose ground state structure is the target structure to an ensemble of random sequences. Here we show that, in certain circumstances, the technique can be applied to real proteins. The resulting energy expression is used to design the beta-sheet surfaces of two real proteins. We find experimentally that the designed proteins are stable and well folded, and in one case is even more thermostable than the wild type.
Models, Chemical↗
Effect of cationic amino acid, L-lysine and its polymers on the growth and secretion of hybridoma cell line OKT-3.
Apart from their pivotal roles in anabolic protein synthesis, cationic amino acids, particularly, L-lysine HCl and its oligomers, up to molecular weight 1000, showed a remarkable property of cellular growth stimulation both in vitro and in vivo. L- and D-Lysine HCl, at a maximal stimulatory concentration of 7 microg/mL of added load of the amino acid, supported a characteristic time-scaled cellular expansion in vitro, and L-lysine-mediated cell expansion in batch cultures always showed a stimulation index (S.I.) ranging up to approximately 35, compared with the matched control populations. Variable S.I. was possibly due to factors such as seeding density, type of media additives, number of passages the cells have undergone before being stimulated, etc. Beyond and before maximal stimulatory concentration of the amino acid, there is a sharp decline in the cellular growth-promoting activity of monomeric L-lysine HCl in vitro, thereby showing a clear concentration window for maximum cellular growth promotion. While the essential amino acid does not have any dedicated cell surface receptor, the monomeric and oligomeric amino acid molecule(s) possibly mediates the serum-derived growth factor-receptor binding on the cell membrane by having two cationic charge centres at two ends of the molecule. Beyond a cutoff molecular weight of 1000, oligomeric lysines did not show any positive effects on either cell division and secretion.
Animals↗
An enigmatic peptide ligation reaction: protease-catalyzed oligomerization of a native protein segment in neat aqueous solution.
We report an enigmatic peptide ligation reaction catalyzed by Glu-specific Staphylococcus aureus V8 protease that occurs in neat aqueous solution around neutral pH utilizing a totally unprotected peptide substrate containing free alpha-carboxyl and alpha-amino groups. V8 protease catalyzed a chain of ligation steps between pH 6 and 8 at 4 degrees C, producing a gamut of covalent oligomers (dimer through octamer or higher) of a native protein segment TAAAKFE (S39) derived from ribonuclease A (RNAse A). Size-exclusion chromatography suggested the absence of strong interaction between the reacting peptides. The circular dichroism spectra of monomer through pentamer showed length-dependent enhancement of secondary structure in the oligomers, suggesting that protease-catalyzed ligation of a monomer to an oligomer resulted in a product that was more structured than its precursor. The relative conformational stability of the oligomers was reflected in their ability to resist proteolysis, indicating that the oligomerization reaction was facilitated as a consequence of the "conformational trapping" of the product. The ligation reaction proceeded in two phases-slow formation and accumulation of the dimer followed by a fast phase of oligomerization, implying that the conformational trap encountered in the oligomerization reaction was a two-step process. The Gly substitution at any position of the TAAAKFE sequence was deleterious, suggesting that the first step of the conformational trap, namely the dimerization reaction, that proceeded very slowly even with the parent peptide, was quite sensitive to amino acid sequence. In contrast, the oligomerization reaction of an Ala analog, AAAAKFE, occurred in much the same way as S39, albeit with faster rate, suggesting that Ala substitution stabilized the overall conformational trapping process. The results suggest the viability of the product-directed "conformational trap" as a mechanism to achieve peptide ligation of totally unprotected peptide fragments in neat aqueous solution. Further, the study projects the presence of considerable innate synthetic potential in V8 protease, baring rich possibilities of protein engineering of this enzyme to generate a "V8 peptide ligase."
Amino Acid Sequence↗
Etiology of sexually transmitted infections among street-based female sex workers in Dhaka, Bangladesh.
An etiological study of sexually transmitted infections (STIs) was conducted among female sex workers (FSWs) in Dhaka, Bangladesh. Endocervical swab and blood samples from 269 street-based FSWs were examined for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis as well as for antibodies to Treponema pallidum and herpes simplex virus 2 (HSV-2). Sociodemographic data and data regarding behavior were also collected. A total of 226 of the 269 FSWs (84%) were positive for the STI pathogens studied. Among the 269 FSWs, 35.5% were positive for N. gonorrhoeae, 25% were positive for C. trachomatis, 45.5% were positive for T. vaginalis, 32.6% were seropositive for T. pallidum, 62.5% were seropositive for HSV-2, and 51% had infections with two or more pathogens.
Animals↗
A pilot study comparing the cognitive demand of walking for transfemoral amputees using the Intelligent Prosthesis with that using conventionally damped knees.
OBJECTIVE: To compare the cognitive demand of walking when using a conventional prosthesis with that using a microprocessor-controlled prosthesis. DESIGN: Ten unilateral transfemoral amputees wearing conventional pneumatic swing phase control (conventional prosthesis) prostheses walked on a treadmill which enforced a pattern of constantly varying speeds. The subjects simultaneously performed a simple or a complex distracting task. Following a period of accustomization, the subjects performed the same test wearing a prosthesis with microprocessor control of swing phase damping (the Intelligent Prosthesis). OUTCOME MEASURES: The three-dimensional trajectory (sway) of a retroreflective marker attached to the forehead was measured by a video-based motion analysis system, and used as a measure of gait quality. The ratio of the sway for the complex task over the simple task (the 'automation index') was used as a measure of the degree of automation of gait. RESULTS: No significant differences were found in the automation index between the two devices. However, the total sway for the conventional prosthesis was significantly higher. Sway during the complex distracting task was significantly higher than during the simple task. CONCLUSIONS: The microprocessor-controlled prosthesis was not found to be less cognitively demanding than a conventional prosthesis.
Adult↗
Bioprosthetic heart valves--replacing order with chaos: electron microscopic study.
Rheumatic heart disease is a significant clinical entity in young children, especially in the developing world. One of the major long-term effects of ill managed rheumatic fever is irreversible damage to the cardiac valve leaflets, primarily on the left side. With the limited success of currently available mechanical and bioprosthetic valves, there is an urgent need for new directions in bioprosthetic valves, both in material, including source, degree of fixation, surface, bulk modifications, etc., and design. In the present paper, new proposals in the material selection and fabrication of bioprosthetic valves are proposed based on electron microscopic studies of natural valve leaflets and the pericardial surface. Current approaches for bioprosthetic valve fabrications include the wide use of the pericardium as a leaflet material. The present study indicates a need for nondestructive surface examination of pericardial sheets for the elimination of areas of surface voids resulting from gross fiber disorientation. Also, there seems to be a need for incorporation of an in situ fiber renewal mechanism in bioprosthetic leaflets to emulate the natural valve more closely. Apparently natural leaflets have built-in fiber renewal mechanism(s).
Animals↗
Analyses of prosthetic episodes in trans-tibial amputees.
The prosthetic episodes, i.e. actual processes of provision, identifying number of prostheses, their maintenance, repairs and replacements were analysed for 104 trans-tibial amputees aged 16 and over, over a 10 year period. The purpose of this investigation was to identify how frequently a new prosthesis is actually required for this group of amputees and what are their maintenance requirements. Variations of requirement between the amputee groups of aged 16-60 and over 60 years are also addressed. In the 10 years period of the study the amputees needed an average of 5.04 new prostheses, 6.25 refits, 2.28 major repairs and 17.04 day repairs. The younger amputees, i.e. below the age of 60 years, required significantly more new prostheses (p=0.003), more refit of sockets (p=0.0012) and more day repairs (p=0.01). Traumatic amputees below the age of 60 years needed significantly more day repairs compared to the non-traumatic amputees in the older age group (p=0.003).
Adolescent↗