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Biomedical subjects

B C Thomas

Publications and source records attributed to B C Thomas.

At least 19 recordsLinked to original sources
PubMed2005

Reliability and validity of the Malayalam hospital anxiety and depression scale (HADS) in cancer patients.

BACKGROUND & OBJECTIVE: The hospital anxiety and depression scale (HADS) has been widely used on cancer patients as an indicator of psychological morbidity. Though the scale has been used in India, no reports are available on translation of HADS in any Indian language and testing the reliability. The present study describes the translation process of HADS into Malayalam and testing its reliability and validity on psychological morbidity in cancer patients. METHODS: The English version of the HADS was translated into Malayalam and was used in this study. The questionnaire was administered to 240 cancer patients and statistical analysis was carried out using Chronbach's alpha to test the internal consistency of the HADS scale while confirmatory factor analysis was carried out using principal axis factoring with equimax rotation and Kaiser Normalization to test its construct validity. RESULTS: The Cronbach's alpha was found to be 0.81 for the HADS anxiety subscale, 0.71 for the HADS depression subscale, and 0.85 for HADS tool. Confirmatory factor analysis (CFA) indicated two depression items (i.e., enjoyment and anhedonia) loading onto the anxiety subscale. Clinical caseness for anxiety was observed in 8 per cent, while 11 per cent of the patients had borderline mood disorder. Clinical caseness for depression was identified in 7.6 and 13 per cent of patients were found to have borderline mood disturbances. INTERPRETATION & CONCLUSION: This preliminary validation study of the Malayalam version of the HADS showed it as an acceptable, and reliable measure of psychological morbidity among cancer patients. The prevalence of anxiety and depression in Indian population was low and enjoyment and anhedonia might present as anxiety initially.

Anxiety↗
PubMed2004

FACT-G: reliability and validity of the Malayalam translation.

BACKGROUND: Emphasis is currently being placed on the need for quality of life in cancer survivors. There is a great need to identify an appropriate tool for quality of life estimation in these linguistically and culturally different settings. PATIENTS AND METHOD: The Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire was translated into the Malayalam language complying with the standard cross-cultural translation methodology. The tool was validated and used for estimating quality of life (QOL) of 214 cancer patients undergoing treatment with curative intent. RESULTS: Cronbach's alpha for the Malayalam version of the FACT-G was 0.8, and for the subscales it ranged from 0.64 to 0.83, compared to source tool alpha of 0.89, with the subscale's ranging from 0.63 to 0.89. The mean overall FACT-G score was 79.8 (standard deviation [SD] = 18.7). Socio-economic factors such as education, education of the spouse, occupation of the spouse, and family income were found to influence FACT-G scores. CONCLUSION: Despite cultural variations, the local Malayalam language version of the FACT-G scale was found to be reliable like the source scale and sensitive cross-culturally. The instrument makes it possible to identify domains influencing QOL and thereby may help direct interventions to them.

Adult↗
PubMed2002

Quality of life in breast cancer patients: validation of a FACT-B Malayalam version.

BACKGROUND: Recent advances in diagnosis and treatment of cancer have led to an increase in cancer survival, and hence, there is a greater emphasis on quality beside quantity of survival. Developing countries too have begun to recognize the need for monitoring quality of life (QOL). However, in most of the developing countries, a validated and reliable tool for the purpose is yet to be realized. MATERIAL AND METHOD: The functional assessment of chronic illness therapy (FACIT) system is a collection of QOL questionnaires targeted to measure QOL in chronic illness. The functional assessment of cancer therapy for breast cancer (FACT-B) was translated into the local language (Malayalam) and tested for validity and reliability. RESULTS: The tool thus developed showed substantial sensitivity, as does the source tool. The Cronbach's alpha for the total FACT-B was 0.87, which is similar to the alpha of 0.9 observed in the FACT-B English version. The mean FACT-B score was 94.3 compared to 112.8 for the source tool. CONCLUSION: The Malayalam translation of the FACT-B questionnaire was developed, tested and validated, and was found satisfactory in comparison to the source tool.

Breast Neoplasms↗
PubMed2002

Psychological distress in cancer patients: hypothesis of a distress model.

A substantial body of research suggests links between stress, coping and cancer. Research also implicates the immune system as a link between stressful events and cancer. The current trend in research in the area of psycho-oncology attempts to define the types of stress and coping mechanisms being used in order to identify predictors of psychological distress. Based on the available review of literature, the impact of distress does seem to play a prominent role in the transition from a state of health to that of ill-health or even a terminal event. In the light of these studies, a distress model for the cancer patient has been hypothesized here.

Humans↗
PubMed2000

Chloroplast ribonuclease P does not utilize the ribozyme-type pre-tRNA cleavage mechanism.

The transfer RNA 5' maturation enzyme RNase P has been characterized in Bacteria, Archaea, and Eukarya. The purified enzyme from all three kingdoms is a ribonucleoprotein containing an essential RNA subunit; indeed, the RNA subunit of bacterial RNase P RNA is the sole catalytic component. In contrast, the RNase P activity isolated from spinach chloroplasts lacks an RNA component and appears to function as a catalytic protein. Nonetheless, the chloroplast enzyme recognizes a pre-tRNA substrate for E. coli RNase P and cleaves it as efficiently and precisely as does the bacterial enzyme. To ascertain whether there are differences in catalytic mechanism between an all-RNA and an all-protein RNase P, we took advantage of the fact that phosphodiester bond selection and hydrolysis by the E. coli RNase P ribozyme is directed by a Mg2+ ion coordinated to the nonbridging pro-Rp oxygen of the scissile bond, and is blocked by sulfur replacement of this oxygen. We therefore tested the ability of the chloroplast enzyme to process a precursor tRNA containing this sulfur substitution. Partially purified RNase P from spinach chloroplasts can accurately and efficiently process phosphorothioate-substituted pre-tRNAs; cleavage occurs exclusively at the thio-containing scissile bond. The enzymatic throughput is fivefold slower, consistent with a general chemical effect of the phosphorothioate substitution rather than with a metal coordination deficiency. The chloroplast RNase P reaction mechanism therefore does not involve a catalytic Mg2+ bonded to the pro-Rp phosphate oxygen, and hence is distinct from the mechanism of the bacterial ribozyme RNase P.

Base Sequence↗
PubMed2000

Evidence for an RNA-based catalytic mechanism in eukaryotic nuclear ribonuclease P.

Ribonuclease P is the enzyme responsible for removing the 5'-leader segment of precursor transfer RNAs in all organisms. All eukaryotic nuclear RNase Ps are ribonucleoproteins in which multiple protein components and a single RNA species are required for activity in vitro as well as in vivo. It is not known, however, which subunits participate directly in phosphodiester-bond hydrolysis. The RNA subunit of nuclear RNase P is evolutionarily related to its catalytically active bacterial counterpart, prompting speculation that in eukaryotes the RNA may be the catalytic component. In the bacterial RNase P reaction, Mg(II) is required to coordinate the nonbridging phosphodiester oxygen(s) of the scissile bond. As a consequence, bacterial RNase P cannot cleave pre-tRNA in which the pro-Rp nonbridging oxygen of the scissile bond is replaced by sulfur. In contrast, the RNase P reaction in plant chloroplasts is catalyzed by a protein enzyme whose mechanism does not involve Mg(II) coordinated by the pro-Rp oxygen. To determine whether the mechanism of nuclear RNase P resembles more closely an RNA- or a protein-catalyzed reaction, we analyzed the ability of Saccharomyces cerevisiae nuclear RNase P to cleave pre-tRNA containing a sulfur substitution of the pro-Rp oxygen at the cleavage site. Sulfur substitution at this position prohibits correct cleavage of pre-tRNA. Cleavage by eukaryotic RNase P thus depends on the presence of a thio-sensitive ligand to the pro-Rp oxygen of the scissile bond, and is consistent with a common, RNA-based mechanism for the bacterial and eukaryal enzymes.

Base Sequence↗
PubMed1995

A subunit interaction in chloroplast ATP synthase determined by genetic complementation between chloroplast and bacterial ATP synthase genes.

F1F0-ATP synthases utilize protein conformational changes induced by a transmembrane proton gradient to synthesize ATP. The allosteric cooperativity of these multisubunit enzymes presumably requires numerous protein-protein interactions within the enzyme complex. To correlate known in vitro changes in subunit structure with in vivo allosteric interactions, we introduced the beta subunit of spinach chloroplast coupling factor 1 ATP into a bacterial F1 ATP synthase. A cloned atpB gene, encoding the complete chloroplast beta subunit, complemented a chromosomal deletion of the cognate uncD gene in Escherichia coli and was incorporated into a functional hybrid F1 ATP synthase. The cysteine residue at position 63 in chloroplast beta is known to be located at the interface between alpha and beta subunits and to be conformationally coupled, in vitro, to the nucleotide binding site > 40 A away. Enlarging the side chain of chloroplast coupling factor 1 beta residue 63 from Cys to Trp blocked ATP synthesis in vivo without significantly impairing ATPase activity or ADP binding in vitro. The in vivo coupling of nucleotide binding at catalytic sites to transmembrane proton movement may thus involve an interaction, via conformational changes, between the amino-terminal domains of the alpha and beta subunits.

Adenosine Triphosphate↗
PubMed1995

Spinach chloroplast RNase P: a putative protein enzyme.

Ribonuclease P (RNase P) is the enzyme responsible for endonucleolytically separating the 5'-leader sequence from precursor tRNA molecules. In bacteria, and in the nuclei and mitochondria of all eukaryotes studied so far, RNase P contains an RNA subunit which is necessary for activity in vitro and in vivo. In contrast, we showed earlier that partially-purified RNase P from spinach chloroplasts had physical properties inconsistent with the presence of any RNA. We now report that the properties of the chloroplast enzyme, after 500 to 1500-fold purification, are consistent with enzymatic activity residing in a approximately 70 kDa polypeptide. Gel filtration chromatography on Sephacryl S-200 and S-300 provides a mass for chloroplast RNase P of approximately 70 +/- 5 kDa. A single polypeptide of approximately 70-80 kDa can be crosslinked to iodoUMP-substituted pre-tRNA. The labeling intensity of this polypeptide corresponds closely to the peak of RNase P activity on Sephacryl S-200 chromatography. Unlike the bacterial ribozyme-type RNase P, chloroplast RNase P is not a metalloenzyme. We showed previously that phosphodiester bond cleavage by the E. coli RNA enzyme absolutely requires Mg2+ or Mn2+ coordinated to the pro-Rp oxygen of the scissile phosphodiester phosphate. In contrast, we now find that chloroplast RNase P has no such requirement, and can accurately and efficiently cleave pre-tRNA containing an Rp-thio-substitution at the scissile bond. These data are entirely consistent with the hypothesis that RNase P in plant chloroplasts is not a ribozyme, but a conventional protein enzyme.

Biological Evolution↗
PubMed1994

Impaired growth in children with asthma during treatment with conventional doses of inhaled corticosteroids.

We describe 6 (4F, 2M) prepubertal children with moderate asthma diagnosed at a mean age of 2.8 years. All patients were treated with inhaled corticosteroids in a dose of between 300 and 800 mcg of beclomethasone dipropionate (becotide) daily, given either as an aerosol or rotahaler. Mean height velocity SDS decreased from -0.8 (range +0.5 to -2.0) to -3.2 (range -1.3 to -4.8) when the dose was increased. Alternatively, when the dose was reduced or stopped, mean height velocity SDS increased from -3.2 (range -2.0 to -4.8) to +0.8 (range -1.2 to +2.7). Careful assessment of height velocity is indicated in all children receiving treatment with inhaled corticosteroids.

Administration, Inhalation↗
PubMed1993

Growth following single fraction and fractionated total body irradiation for bone marrow transplantation.

Total body irradiation (TBI) is used as preparative regimen prior to bone marrow transplantation (BMT). Since there are more long-term survivors, follow up studies are important. We have performed a retrospective analysis of growth for 49 children, who had undergone treatment with cyclophosphamide and TBI before BMT. Of these patients 26 received single fraction (SF) TBI as a dose of 900-1000 cGy, whereas 23 received fractionated (FF) TBI as a total dose of either 1200 cGy divided in six fractions or 1440 cGy divided in eight fractions over 3 days. Half of the patients in the SF-TBI group, and 9 in the FF-TBI group had received low-dose cranial irradiation prior to TBI. In all groups a decrease in height SDS was observed. By evaluating the major factors leading to growth impairment the influence of cranial irradiation, which was demonstrable in the 1st year after TBI, could not be shown after 3 years. At this time growth was significantly more impaired in the SF group with a mean height SDS of -0.9 (+/- SD 0.9) compared to a mean height SDS -0.22 (1.02) in the FF group (P < 0.05). Measurement of segmental proportions showed a significant difference in SDS for sitting height in comparison to SDS for subischial leg length, irrespective of the TBI regimen. This was already evident 1 year after TBI and decreased during the following years. Twenty four of the patients (17 in the single fraction and 7 in the fractionated TBI group) were treated with growth hormone, but demonstrated an inappropriate response with absent catch-up growth in their legs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Long-term treatment with growth hormone in Noonan's syndrome.

Five children (four boys, one girl) with Noonan's syndrome were treated with growth hormone for a mean of 2.9 (range 1.8 to 4.6) years. Treatment was commenced at a mean age of 3.9 (range 2.5 to 6.0) years. After one year of treatment, height velocity SDS increased from a mean of -2.1 (range -4.1 to -0.3) to a mean of +3.1 (range +2.0 to +3.5). Subsequently, height SDS increased significantly from -3.3 (range -4.2 to -2.2) to -2.4 (range -3.3 to -1.6). Although in all patients a marked decrease in height velocity was observed in the following years of treatment, compared to the first year, height SDS continued to improve in comparison to pretreatment (mean height SDS in the third year for four patients was -2.1) (range -3.1 to -1.4). In the four patients who had completed their second year of treatment, height SDS for bone age had increased from -1.8 (range -2.8 to -0.9) to -1.2 (range -1.6 to -0.6).

Child↗
PubMed1993

Gonadotropin releasing hormone analogue and growth hormone therapy in precocious and premature puberty following cranial irradiation for acute lymphoblastic leukaemia.

Ten girls with early puberty secondary to cranial irradiation as a part of the treatment for acute lymphoblastic leukaemia (ALL) were treated with either gonadotropin-releasing hormone analogue (GnRHa) and human growth hormone (GH) (8 girls) or with GnRHa alone (2 girls). After 4 years of treatment, height SDS for bone age was improved in the group who received combined treatment (from -0.97 to +0.07, p < 0.001), in contrast to the 2 patients who received GnRHa alone in whom height standard deviation scores for bone age decreased (from -1.10 to -1.33). Sitting height in all patients was relatively shorter than leg length, and there was no significant alteration during the 4 years of treatment.

Age Determination by Skeleton↗
PubMed1993

Endocrine function following single fraction and fractionated total body irradiation for bone marrow transplantation in childhood.

Forty-nine children who had undergone treatment with cyclophosphamide and total body irradiation before bone marrow transplantation were investigated for impaired endocrine function. Twenty-six patients received single fraction total body irradiation as a dose of 9-10 Gy, whereas 23 patients received fractionated total body irradiation as a total dose of either 12 Gy divided into six fractions or 14.4 Gy divided into eight fractions, administered over 3 or 4 days. Half of the patients in the single fraction group and nine in the fractionated group had received cranial irradiation prior to total body irradiation. Pathological changes in thyroid function were observed in 19 patients (73%) of the single fraction group (elevated thyrotrophin (58%) and decreased thyroxine levels (15%)), whereas in the fractionated group only six patients (25%) developed transient raised thyrotrophin levels: the mean observation period was 3.2 years in the single fraction group and 2.7 years in the fractionated group. The stimulated growth hormone peak concentration was influenced significantly by previous cranial irradiation and was independent of the type of total body irradiation administered. In the patients who had received cranial irradiation, the mean growth hormone peak levels were 8.4 mU/l (single fraction group) and 13.9 mU/l (fractionated group), whereas in those who received only total body irradiation they were 24.9 mU/l(single fraction group) and 28.1 mU/l (fractionated group). The basal gonadotrophin concentration in children older than 9 years showed elevated levels in nine patients (50%) of the single fraction group and in only three patients (30%) of the fractionated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1979

The maturing teenage mother.

The public consciousness about teenage childbearing and its associated hazards has been raised through widespread documentation of the phenomenon. This study was conducted to obtain information from maturing teenage mothers about their lifestyles, health habits and attitudes towards family planning. Results showed some definite trends with age maturity. Recommendations include the development of services for males, programs for parents, increased use of media and existing community resources, expansion of clinic services to be more amenable to teenagers and increased education about nonprescription methods of family planning.

Adolescent↗
PubMedDate not supplied

Rehabilitation of cancer patients.

With the developments in cancer treatment, more and more patients are surviving their disease. However, very little emphasis is being placed to rehabilitate these cancer survivors. Ignorance, social structure, stigma attached in seeking psychological help, and poor communication skills of oncology staff all contribute to poor rehabilitative efforts. The priority of governmental agencies and health efforts to fight rampant communicable diseases, malnutrition, maternal health, and the frequent natural calamities, puts rehabilitation movements in the back seat. Treatment and prevention of disability and its rehabilitation requires comprehensive and multidisciplinary approach. There is an urgent need to promote physical and psychological rehabilitation.

Adaptation, Psychological↗
PubMedDate not supplied

Development of a distress inventory for cancer: preliminary results.

CONTEXT: Advances in cancer treatment have led to cure and prolongation of patients' lives; however associated psychosocial problems, including distress, can detrimentally affect patients' compliance with treatment and ultimately, their outcome. Symptom distress has been well addressed in many studies; however, psychological distress has only been quantified by using depression or anxiety scales/checklists or quality of life scales containing a distress sub scale/component or by the use of scales that are not psychological distress-specific. AIMS: The present study is an attempt to construct a psychological distress inventory for specific use with cancer patients. SETTINGS AND DESIGN: The standardisation sample consisted of 63 randomly selected patients with head and neck cancer who had undergone/ were undergoing curative treatment at the Regional Cancer Centre, Trivandrum. PATIENTS AND METHODS: The Distress Inventory for Cancer contained 57 positively and negatively toned items. An item analysis was conducted, followed by a factor analysis, thereby identifying the domains influencing distress. RESULTS: The final questionnaire contained 26 items subdivided into four domains viz. the personal, spiritual, physical, and the family domains, with each domain providing a sub score. The reliability coefficient (Cronbach's alpha) of the scale was found to be 0.85. CONCLUSIONS: These are the preliminary results of an ongoing study on global distress and tool development process. Reported here is the first step towards development of such tool.

Adolescent↗