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Biomedical subjects

D Datta

Publications and source records attributed to D Datta.

At least 37 records · Page 2Linked to original sources
PubMed1998

Cell culture approach to biocompatibility evaluation of unconventionally prepared hydroxyapatite.

Hydroxyapatite (HA), Ca10(PO4)6(OH)2 was produced by microwave irradiation of calcium nitrate (CaNO3.4H2O) and di-ammonium phosphate in aqueous solution. The HA formation was confirmed by X-ray diffraction analysis. HA prepared by this unconventional route was subjected to biocompatibility assay by a cell-culture method using the hybridoma cell line AE9D6 in both conventional Dulbecco's modification of Eagle's medium (DMEM) and simulated body fluid (SBF), both supplemented with 5% fetal calf serum. HA synthesised through this unconventional method showed the presence of tricalcium phosphate which can be reduced only after heat treatment at 1150 degrees C. The HA conformed to the X-ray data index file for hydroxyapatite. Biocompatibility assays showed reproducible growth and secretion patterns of cells both in DMEM as well as in SBF, thereby indicating the effectiveness of this method for the production of biocompatible HA.

Animals↗
PubMed1998

Transition from school to adult life for physically disabled young people.

The transition process for young physically disabled people (n = 87) was studied in three districts to determine how it varied between schools, and how it was perceived by the disabled and their carers. The experiences of the young people were compared with guidelines for good practice based on relevant legislation. Results showed that young disabled people experienced a poor handover to adult services if they had no "statement of special educational need" or if they went to further education college. Young people with cerebral palsy or complex multiple problems fared less well than those with spina bifida or juvenile chronic arthritis. There are several deficiencies in the legislation. Physically disabled young people should receive a transition review regardless of whether they have a "statement". The range of severity and type of disorders among the young physically disabled argues for a range of services--the category is too broad to be useful for research, service planning, and provision.

Adolescent↗
PubMed1998

Conventional versus microchip controlled pneumatic swing phase control for trans-femoral amputees: user's verdict.

A questionnaire survey of 22 selected transfemoral amputees who were switched from pneumatic swing phase control knee joints (PSPC) to microprocessor controlled intelligent knee joints (IP) is presented. On overall rating all respondents considered the IP to be an improvement or a great improvement compared to the PSPC and none decided to revert back or wished to use their previous PSPC prosthesis on a regular basis. However the IP was not rated to be superior in every area of the questionnaire. Walking at different speeds, walking further, reduction of energy consumption were the main areas where subjective improvements were perceived by the amputees themselves. It is strongly believed that patients' own views should be an important and integral part of the evaluation of new prosthetic technology.

Adult↗
PubMed1998

Powered prosthetic hands in very young children.

Myoelectric prostheses are generally not provided in the United Kingdom for children before the age of 3 1/2 years. Following the introduction of a smaller sized electric hand in the United Kingdom in 1993 the authors decided to introduce electrically powered hands for a group of congenital upper limb deficient children at a much younger age compared to normal practice. Eleven children were introduced to powered prosthetic hands at an average age of 20.6 months. At the review carried out for the purpose of this paper. 72.7% of these children appeared to be successfully using these powered prostheses. Fitting these young children with powered prostheses and encouraging acceptance and operation of the prostheses appeared to be much less of a problem than might have been anticipated. The parents of all these children have very much liked the introduction of powered hands at this early age and have contributed positively to the prosthetic programme. The authors' experience suggests that introduction of a powered prosthesis at a much earlier age can be a more suitable alternative than provision of a body-powered prosthetic device while waiting to reach an older age before a powered prosthesis is considered.

Arm↗
PubMed1998

Quadriceps muscle injury in trans-femoral amputees.

Two male trans-femoral amputees using modular trans-femoral prostheses lost control and fell to the ground when their prosthetic knees gave way. The semi-automatic knee lock malfunctioned in the first case while the free knee stabilising mechanics gave way in the second case. This resulted in a high tensile force acting on the contralateral quadriceps muscle causing it to rupture. As there are a significant number of patients with both kinds of prostheses it is important to be aware of this possibility so that necessary actions can be taken to minimise its occurrence. Even with the currently available weight activated stance phase control, the prosthetic knee will give way if the knee is flexed more than 20 degrees on weight bearing. Good power and control of hip extensors on the amputation side is needed to control the prosthetic knee joint, especially in the early stage of the walking cycle, i.e., from heel strike to mid-stance. Quadriceps muscle injury in amputees, as far as the authors are aware, has not been reported previously.

Aged↗
PubMed1998

Getting higher yields of monoclonal antibody in culture.

Getting higher yields of monoclonal antibody (MAb) is a problem in Hybridoma Technology which has two major bottlenecks: a) poor yield of hybridized cells, b) low cellular productivity of MAb in culture. There are three ways of obtaining high MAb yield in vitro a) Large scale culture, b) high density culture and c) enhancing individual cellular productivity in culture. Currently, the focus is on the correct synergistic combination of fortified nutrient media, bioreactor design and mode of operation. Maximization of cell culture longevity, maintenance of high specific antibody secretion rates, nutrient supplementation, waste product minimization and control of environmental conditions are important parameters for improvement of large scale production of MAb. Though, MAb yields have improved rapidly over the decade, there is a growing concern for the decrease in quality of MAb secreted. Further research is therefore necessary to take full advantage of MAb as a potential diagnostic agent for in vivo therapy.

Animals↗
PubMed1998

Monoclonal antibody: high density culture of hybridoma cells and downstream processing for IgG recovery.

Getting higher yields of monoclonal antibody (MAb) is a problem in Hybridoma Technology which has two major bottlenecks--(a) poor yield of hybridized cells; and (b) low cellular productivity of MAb in culture. There are three ways of obtaining high MAb yield in vitro--(a) large scale culture of hybrid cells; (b) high density culture; and (c) enhancing individual cellular productivity in culture. Currently, focus is on correct synergistic combination of fortified nutrient media, bioreactor design and mode of operation. Maximisation of cell culture longevity, maintenance of high specific antibody secretion rates, nutrient supplementation, waste product minimization and control of environmental conditions are important parameters for improvement of large scale production of MAb. Though, MAb yield has enhanced rapidly over the decade, there is a growing concern for decrease in quality of MAb secreted. Further research is therefore necessary to take full advantage of MAb as a potential diagnostic agent for in vivo therapy.

Animals↗
PubMed1997

Conformationally driven protease-catalyzed splicing of peptide segments: V8 protease-mediated synthesis of fragments derived from thermolysin and ribonuclease A.

We have studied the conformation as well as V8 protease-mediated synthesis of peptide fragments, namely amino acid residues 295-316 (TC-peptide) of thermolysin and residues 1-20 (S-peptide) of ribonuclease A, to examine whether "conformational trapping" of the product can facilitate reverse proteolysis. The circular dichroism study showed cosolvent-mediated cooperative helix formation in TC-peptide with attainment of about 30-35% helicity in the presence of 40% 1-propanol and 2-propanol solutions at pH 6 and 4 degrees C. The thermal melting profiles of TC-peptide in the above cosolvents were very similar. V8 protease catalyzed the synthesis of TC-peptide from a 1:1 mixture of the non-interacting complementary fragments (TC295-302 and TC303-316) in the presence of the above cosolvents at pH 6 and 4 degrees C. In contrast, V8 protease did not catalyze the ligation of S1-9 and S10-20, although S-peptide could assume helical conformation in the presence of the cosolvent used for the semisynthetic reaction. V8 protease was able to synthesize an analog of S-peptide (SA-peptide) in which residues 10-14 were substituted (RQHMD-->VAAAK). While S-peptide exhibited helical conformation in the presence of aqueous propanol solutions, SA-peptide displayed predominantly beta-sheet conformation. SA-peptide showed enhanced resistance to proteolysis as compared with S-peptide. Thus, failure of semisynthesis of S-peptide may be a consequence of high flexibility around the 9-10 peptide bond due to its proximity to the helix stop signal. The results suggest that protease-mediated ligations may be achieved by design and manipulation of the conformational aspects of the product.

1-Propanol↗
PubMed1997

A prospective study of the effect of limb-threatening ischaemia and its surgical treatment on the quality of life.

OBJECTIVE: To assess the quality of life after treatment for limb-threatening ischaemia. DESIGN: An open, prospective, observational study in a Vascular Unit of a University Hospital. MATERIALS: One hundred and fifty consecutive patients presenting with actual or threatened tissue loss of the leg. METHODS: A single, experienced observer assessed the patients for pain, mobility, anxiety, depression, self-care and lifestyle at presentation, 6 and 12 months later. RESULTS: Six different treatment outcomes were recognised: successful angioplasty, successful thrombolysis/thrombectomy, successful surgical bypass, amputation after failed revascularisation, primary unilateral amputation and primary bilateral amputation. Pain was significantly improved in all groups (p < 0.05) except for patients after failed revascularization (p = 0.08). Mobility improved in patients who underwent angioplasty (p = 0.05) or a successful surgical bypass (p = 0.001). Anxiety and depression both improved significantly only after surgical reconstruction (p < 0.02). Self-care ability improved significantly after angioplasty (p < 0.05), surgical reconstruction (p < 0.005) and unilateral primary amputation (p < 0.05), but was unaltered in the other groups. Lifestyle significantly deteriorated following thrombolysis/thrombectomy and failed surgical reconstruction (p < 0.05), but was maintained in all other groups. CONCLUSIONS: The treatment of limb-threatening ischaemia should aim to maintain pre-morbid lifestyle, an aim which is best achieved by limb-salvage. The patient's own expectations and needs have a major bearing on the choice of therapy.

Activities of Daily Living↗
PubMed1996

The costs of managing lower limb-threatening ischaemia.

One hundred and fifty consecutive patients presenting with limb-threatening ischaemia were studied prospectively to determine treatment and rehabilitation costs in the first year. Limb salvage was attempted in 104 (69%) patients but failed in 13%. Mortality at 1 year was 27%. The cost of treatment, inpatient stay, occupational therapy, physiotherapy, convalescence, disablement services, home adaptations, home care, district nursing, transportation and outpatient visits were determined for each patient. The patients were classified according to their presentation and initial treatment into five groups (number of patients) whose median management costs (interquartile range) for 12 months were: Gp 1 (23 - Revascularisation for acute ischaemia = 3970 pounds (2984-5511) Gp 2 (29) - Angioplasty for critical ischaemia = 6611 pounds (3630-10,200) Gp 3 (52) - Reconstruction for critical ischaemia = 6766 pounds (4337-9677) Gp 4 (34) - Primary amputation = 10,162 pounds (7894-13,026) Gp 5 (12) - Primary bilateral amputations = 13,848 pounds (11,440-18,056) At 1 year, there was no significant difference in the cost of managing a patient with a critically ischaemic limb by angioplasty or surgical reconstruction. The cost of revascularisation for acute ischaemia was comparatively low because these patients required minimal rehabilitation. The median cost of managing a patient following amputation was almost twice that of successful limb salvage justifying an aggressive revascularisation policy. However, justification of such a policy on economic grounds requires salvage failure episode to be minimised as they increase costs considerably.

Absenteeism↗
PubMed1996

Outcome of fitting an ICEROSS prosthesis: views of trans-tibial amputees.

A report of the outcome of fitting ICEROSS prostheses to trans-tibial amputees from a subregional amputee rehabilitation centre is presented. This work has mainly concentrated on obtaining patients' own views to judge advantages and disadvantages of ICEROSS compared to their previous patellar-tendon-bearing (PTB) prostheses. Sixty-nine patients were entered for this study, but the results of the study are based on 54 patients who responded. Fifteen patients (27.7%) had rejected their ICEROSS prosthesis at the time of the study. Provision of ICEROSS prostheses did not improve indoor and outdoor walking abilities in terms of distance or use of other walking aids, nor were they more comfortable to wear. An increase in sweating in the first 3 months of wearing ICEROSS was significant, but settled afterwards. The amputees considered that the rate of stump skin breakdown with ICEROSS compared to their PTB prostheses was significantly less. Walking up and down stairs was more comfortable and in general overall rating of ICEROSS prostheses they were scored significantly higher by the amputees themselves. It is concluded that appropriate patient selection is vital and in certain cases ICEROSS will provide considerable benefits to the amputees.

Activities of Daily Living↗
PubMed1996

Activities and users' views of a special seating clinic.

We carried out an audit of the activities of a subregional special seating clinic from the departmental records covering a period of 1 year. A total of 113 patients were seen in the clinic; 64.6% of these were first-time referrals. Cerebral palsy was given as the primary diagnosis for 84.9% of the patients and the mean age was 12.2 years; 62.8% of the patients were provided with special seats, whereas 21.2% needed only a change of wheelchair to a more appropriate model. Though there appears to be a fairly high degree of satisfaction of the special seating clinic, the need for agreed and recorded goals at the assessment clinics, regular review arrangements and further research into usage pattern, as well as in other areas of special seating, is identified.

Adolescent↗
PubMed1995

Surgery for limb threatening ischaemia: a reappraisal of the costs and benefits.

OBJECTIVES: To study the quality of life of patients following surgery for critical limb is ischaemia. DESIGN: Part retrospective, part prospective open study. SETTING: Vascular unit of a University Hospital. MATERIALS: Seventy-nine consecutive patients, medium age 75 years (range 44 to 94), who presented with leg threatening ischaemia and who underwent successful revascularisation or a major amputation were studied. CHIEF OUTCOME MEASURES: Six separate quality of life measures were recorded at 6 months: pain, mobility, anxiety, depression, activities of daily living (Barthel) and lifestyle (Frenchay). MAIN RESULTS: The mortality of this group of patients after six months was 24%. Forty-seven patients were available for quality of life assessment six months after initial intervention. Overall, amputation was more costly than successful revascularisation and limb salvage. Limb salvage resulted in greater mobility (p < 0.001) and better performance in self-care (p < 0.001) and lifestyle (p = 0.006), but produced more anxiety and depression (p = 0.04) than major amputation. A subgroup of patients who had major amputation after a failed limb salvage operation consumed a disproportionate amount of resources and, although their mobility was typical of amputees, their self-care and lifestyle scores were similar to those who had successful limb salvage. OBSTRUCTIONS: Limb salvage is attempted in up to 22% of patients for whom primary amputation may provide more expeditious rehabilitation with minimal impairment of their lifestyle performance.

Activities of Daily Living↗