Biomedical subjects

N N Singh

Publications and source records attributed to N N Singh.

At least 19 recordsLinked to original sources

PubMed2006

Transforming growth factor-beta-regulated expression of genes in macrophages implicated in the control of cholesterol homoeostasis.

The regulation of macrophage cholesterol homoeostasis is of crucial importance in the pathogenesis of atherosclerosis, an underlying cause of heart attack and stroke. Several recent studies have revealed a critical role for the cytokine TGF-beta (transforming growth factor-beta), a key regulator of the immune and inflammatory responses, in atherogenesis. We discuss here the TGF-beta signalling pathway and its role in this disease along with the outcome of our recent studies on the action of the cytokine on the expression of key genes implicated in the uptake or efflux of cholesterol by macrophages and the molecular mechanisms underlying such regulation.

Animals↗

PubMed2006

Assessing the effects of stimulation versus microswitch-based programmes on indices of happiness of students with multiple disabilities.

BACKGROUND: Stimulation and microswitch-based programmes are considered main strategies to promote indices of happiness in students with multiple disabilities. However, only limited attempts have been made to assess the relative effects of the two programmes. This study conducted such an assessment with seven students with multiple disabilities. METHODS: The first four phases of the study served to: (1) provide the students with a systematic exposure to each of the programmes; and (2) measure the programmes' effects on indices of happiness by comparing them with baseline levels. The fifth phase served to compare the programmes with each other. RESULTS: The first four phases of the study showed that the microswitch-based programme produced a significant increase in indices of happiness for all seven students, and the stimulation programme produced a significant increase for six students. During the fifth phase of the study (i.e. when the two programmes were alternated), the microswitch-based programme promoted significantly higher indices of happiness than the stimulation programme for four of the seven students. CONCLUSIONS: Microswitch-based programmes might be deemed preferable to stimulation programmes because they can promote higher or comparable indices of happiness while promoting the acquisition of adaptive responses and self-determination.

Child↗

PubMed2006

Multiple microswitches for persons with multiple disabilities: a basic procedure to examine the persons' choice behavior.

This study examined a basic choice-analysis procedure to clarify choice between two responses and related stimuli by five persons with multiple disabilities ages 17.1 to 50.2 yr. The procedure was based on reversing the links between responses and stimuli to assess whether the stimuli accounted for differences in response levels. When this was not the case, the procedure added extra stimuli for the less preferred response to judge whether such an increase would compensate for the apparent disadvantage of that response, e.g., its higher physical cost. Analysis showed that the choice of three of the five participants seemed motivated by the stimuli following the responses. The choice of the other two persons seemed related to a preference for one of the responses which was partially or largely modified when extra stimuli were added.

Adolescent↗

PubMed2006

Writing program with word prediction for a young man with multiple disabilities: a preliminary assessment.

This study assessed a writing program with word prediction, which completed the writing of a word and spoke it out only when there was certainty that such a word was the correct one. The assessment was carried out with a young man with multiple disabilities, who typically used a word-processing program without word prediction. The two programs were compared on the time required by the participant for writing general sentences, through a social validation assessment, and eventually a check on the participant's preference. Analysis showed the program with word prediction was significantly more effective in terms of the writing time, which was halved, and was deemed preferable by 40 raters (psychology students) involved in the social validation assessment and by the participant himself. Implications of the findings are discussed.

Adult↗

PubMed2006

Enabling a man with multiple disabilities and limited motor behavior to perform a functional task with help of microswitch technology.

This study evaluated the extent to which two microswitches used as interfaces would enable a man with multiple disabilities and limited motor behavior to operate an electric door opener at the entrance of the day center that he attended. Analysis showed the man (a) learned to use the two microswitches, (b) preferred the microswitch placed at his wheelchair's footrest (which also allowed more effective responding) over the microswitch placed at his wheelchair's armrest, and (c) maintained his positive performance at the 1- and 2-mo. postintervention checks. The results were discussed from a technical and practical standpoint and in terms of implications for the quality of life of persons with disabilities.

Adult↗

PubMed2006

Enabling persons with multiple disabilities to choose among environmental stimuli and request stimulus repetitions through microswitch and computer technology.

This study assessed microswitch and computer technology to enable two participants with multiple disabilities, 32 and 19 years of age, to choose among environmental stimuli and request their repetition whenever they so desired. Within each session, 18 stimuli (12 preferred and 6 nonpreferred) were available. For each stimulus, a computer system provided a sample of 3 sec. duration. During the intervention, participants' vocal responding in relation to a stimulus sample activated a microswitch and a computer system turned on that stimulus for 15-30 sec. When participants did not vocally respond, the computer system paused briefly and then presented the next scheduled stimulus sample. When participants vocally responded at the end of a stimulus presentation, the stimulus was repeated. Intervention data showed that the participants learned to choose preferred stimuli and bypass nonpreferred ones as well as to request repetitions of the preferred stimuli. This performance was maintained at a 1-mo. postintervention check and transferred to sets of stimuli not used in the intervention. The implications of these results were discussed.

Adult↗

PubMed2005

Two-generation marker-aided backcrossing for rapid conversion of normal maize lines to quality protein maize (QPM).

The low nutritive value of maize endosperm protein is genetically corrected in quality protein maize (QPM), which contains the opaque 2 gene along with numerous modifiers for kernel hardness. We report here a two generation marker-based backcross breeding program for incorporation of the opaque 2 gene along with phenotypic selection for kernel modification in the background of an early maturing normal maize inbred line, V25. Using the flanking marker distances from opaque 2 gene in the cross V 25 xCML 176, optimum population size for the BC(2) generation was computed in such a way that at least one double recombinant could be obtained. Whole genome background selection in the BC(2) generation identified three plants with 93 to 96% recurrent parent genome content. The three BC(2)F(2) families derived from marker identified BC(2) individuals were subjected to foreground selection and phenotypic selection for kernel modification. The tryptophan concentration in endosperm protein was significantly enhanced in all the three classes of kernel modification viz., less than 25%, 25--50% and more than 50% opaqueness. BC(2)F(3) lines developed from the hard endosperm kernels were evaluated for desirable agronomic and biochemical traits in replicated trials and the best line was chosen to represent the QPM version of V25, with tryptophan concentration of 0.85% in protein. The integrated breeding strategy reported here can be applied to reduce genetic drag as well as the time involved in a conventional line conversion program, and would prove valuable in rapid development of specialty corn germ plasm.

Crosses, Genetic↗

PubMed2005

Microswitch clusters to enhance adaptive responses and head control: a programme extension for three children with multiple disabilities.

PURPOSE: We assessed the possibility of extending adaptive responding and head control in three children with multiple disabilities through the use of microswitch clusters. METHOD: The children had previously learned to perform an adaptive hand response and to control head position during that response. They were now taught one or two new adaptive responses (foot lifting, leg touching, or vocalization) and to combine such responses with appropriate head position. Microswitch clusters served to ensure that an adaptive response was followed by positive stimulation only if it was combined with appropriate head position. RESULTS: The results were positive with the children learning the new adaptive responses and combining them with appropriate head position. This performance was maintained during two- or three-month post-intervention checks. During these checks, the children were also successful in using the old adaptive hand response with appropriate head position. CONCLUSIONS: The use of microswitch clusters was effective to extend the level of adaptive responding and enhance appropriate head position during this responding. This outcome, which indicates a successful technical replication and procedural extension of previous work in the area, has positive practical implications for educational and occupational programmes for children with multiple disabilities.

Child↗

PubMed2005

Identification and validation of QTLs conferring resistance to sorghum downy mildew (Peronosclerospora sorghi) and Rajasthan downy mildew (P. heteropogoni) in maize.

We have mapped the quantitative trait loci (QTLs) conferring resistance to sorghum downy mildew (Peronosclerospora sorghi; SDM) and Rajasthan downy mildew (P. heteropogoni; RDM), two species of DM prevalent throughout India. QTL mapping was carried out on a backcross population of 151 individuals derived from a cross between CM139 (susceptible parent) and NAI116 (highly resistant to both SDM and RDM). Heritability estimates were 0.74 for SDM and 0.67 for RDM. Composite interval mapping combined with a linkage map constructed with 80 simple sequence repeat (SSR) markers resulted in the identification of three QTLs (one each on chromosomes 2, 3 and 6) for SDM resistance and two QTLs (one each on chromosomes 3 and 6) for RDM resistance, all of which were contributed by NAI116. The significance of the major QTL on chromosome 6 (bin 6.05) that confers resistance to diverse DMs in tropical Asia, including SDM and RDM in India, was also verified. The results confirmed that some common QTLs contribute to both SDM and RDM resistance, while additional loci might specifically govern resistance to SDM. The QTL information generated in this study provide information that will aid in undertaking an integrated breeding strategy for the transfer of resistance to SDM and RDM in maize lines using marker-assisted selection.

Breeding↗

PubMed2005

An overview of research on increasing indices of happiness of people with severe/profound intellectual and multiple disabilities.

PURPOSE: This paper was to provide an overview of research studies aimed at increasing indices of happiness of persons with severe/profound intellectual and multiple disabilities. METHODS: Computerized and manual searches were carried out to identify the studies published from 1990 to 2004 (i.e., the period during which the issues of quality fo life and happiness in people with disabilities have become more prominent). Twenty-four research studies were identified. They involved the use of six different procedures, that is, structured stimulation sessions, microswitch-based simulation sessions, leisure activities and favourite work tasks or conditions, positive environment or positive behaviour support programmes and mindful caregiving, favourite stimulation automatically delivered on exercise engagement, and snoezelen. RESULTS AND CONCLUSION: Data tended to be positive with increases in the participants' indices of happiness, but some failures also occurred. The outcomes were discussed in relation to (a) methodological issues, such as designs of the studies, length of the intervention, and number of participants, and (b) personal and practical implications of the procedures. Some suggestions for future research (particularly focused on extending evidence and overcoming present methodological weakness) were also examined.

Behavior Therapy↗

PubMed2005

Bilateral orbital cellulitis due to Neisseria gonorrhoeae and Staphylococcus aureus: a previously unreported case.

Cellulitis of the orbit is a common cause of proptosis in children, and also frequently arises in the elderly and the immunocompromised. The condition is characterized by infection and swelling of the soft tissues lining the eye socket, pushing the eye ball outwards and causing severe pain, redness, discharge of pus and some degree of blurred vision. There is a small risk of infection spreading to the meninges of the brain and causing meningitis. This paper reports the case of an adult in whom polymicrobial bilateral orbital cellulitis had developed due to Staphylococcus aureus and Neisseria gonorrhoeae infection. N. gonorrhoeae infections are acquired by sexual contact. Although the infection may disseminate to a variety of tissues, it usually affects the mucous membranes of the urethra in males and the endocervix and urethra in females. To the authors' knowledge this is the first report of polymicrobial bilateral orbital cellulitis due to S. aureus and N. gonorrhoeae in medical literature.

Adult↗

PubMed2005

Extending the evaluation of a computer system used as a microswitch for word utterances of persons with multiple disabilities.

BACKGROUND: Micro-switches can be vital tools to help individuals with extensive multiple disabilities acquire control of environmental stimulation. This study was aimed at extending the evaluation of a computer system used as a microswitch for word utterances with three participants with multiple disabilities. METHOD: Sets of 7 or 12 word utterances were used for the participants. The utterances were divided into three groups, which were exposed to intervention successively. During the intervention and a 2-month post-intervention check, the participants' emission of the target utterances led the system to present favourite, matching stimuli (i.e. provided that it recognized the utterances). RESULTS: Intervention data showed that (1) the participants increased the frequencies of the target utterances and (2) the computer system recognized approximately 80% of those utterances. These findings were maintained at the post-intervention check. An analysis of the levels of occurrence of individual utterances showed statistically significant differences among them, in line with the notions of preference and choice. CONCLUSIONS: The computer system was useful as a microswitch to enable access to favourite stimuli. There is a need to improve the accuracy of the system with respect to its recognition of the participants' utterances.

Adolescent↗

PubMed2005

Further evaluation of microswitch clusters to enhance hand response and head control in persons with multiple disabilities.

This study was a further evaluation of microswitch clusters (combinations of two microswitches) to improve adaptive responding together with correct head position in two persons with multiple disabilities. The two participants were 19.7 and 6.6 yr. old and had profound intellectual disabilities, spastic tetraparesis, and visual impairment. They were initially taught an adaptive hand response that activated a pressure microswitch and produced favorite stimulation. Thereafter, their performance of the hand response produced favorite stimulation only when it was combined with a correct head position (detected through a mercury microswitch). Analysis showed that both participants increased the frequency of the hand response and, subsequently, the percentage of times they emitted this response in combination with correct (upright) head position. In essence, they were able to coordinate constructive occupation with exercise of appropriate posture. Performance was maintained at a 2-mo. postintervention check.

Adult↗

PubMed2005

A microswitch cluster to enhance arm-lifting responses without dystonic head tilting by a child with multiple disabilities.

This study assessed whether a microswitch duster with favorite stimulation could help a 9.1-yr.-old child with multiple disabilities increase arm-lifting responses without dystonic, sideways head tilting. The microswitch cluster involved two microswitches, one at the child's arm to monitor the lifting response, and the other at the child's head to monitor whether it was tilted during arm lifting. Analysis showed that the percentage of arm-lifting responses occurring without head tilting increased most visibly when favorite stimulation focused on those (appropriate) responses.

Arm↗

PubMed2005

Assessing a microswitch-based stimulation procedure for eye-blinking responses in a young woman with profound multiple disabilities.

We applied a new microswitch-based stimulation procedure for eye-blinking responses with a young woman with profound multiple disabilities, and compared effects of this procedure on the eye-blinking responses and smiling with the effects of a caregiver-based stimulation condition. Analysis showed that the microswitch-based stimulation procedure, with stimulation occurring contingent on eye-blinking responses, increased the frequencies of these responses significantly above the levels recorded in baseline and caregiver-based stimulation conditions. No changes in smiling frequencies occurred. Implications of the findings in terms of alertness, learning, and quality of life are discussed.

Affect↗

PubMed2005

Automatic prompting to reduce persistent tongue protrusion in a woman with severe to profound mental retardation.

This study assessed whether an intervention approach relying on auditory prompting delivered automatically through a portable device was effective to reduce tongue protrusion in a woman with severe to profound mental retardation. The device involved (a) an optic sensor, i.e., a miniphotocell kept under the lower lip with medical tape, (b) a small signal transmission box, and (c) a Walkman for presenting the prompts. Initially, the automatic prompting condition was combined with occasional praise from a research assistant for having the tongue in the mouth. Analysis showed that the occurrence of tongue protrusion dropped from about 65% of the observation time during the initial baseline to less than 5% through the intervention. The study lasted 4.5 mo.

Adult↗

PubMed2004

Microswitch clusters to support responding and appropriate posture of students with multiple disabilities: three case evaluations.

PURPOSE: This study extended the evaluation of microswitch clusters to support responding and appropriate posture with three students with multiple disabilities. METHOD: Initially, a baseline level was established for the target response selected for each student. Then, Intervention I was implemented to increase the frequency of that response through the presentation of favourite stimuli. During Intervention II, the response was followed by favourite stimuli only if the microswitch cluster detected it in combination with appropriate posture. Post-intervention checks were carried out within 2 or 3 months from the end of Intervention II. RESULTS AND CONCLUSIONS: All students showed an increase in the frequency of the target response during Intervention I and in the percentage of times the response occurred in combination with appropriate posture during Intervention II. These changes lasted over time. The importance of microswitch clusters to enhance the performance of students with multiple disabilities was underlined.

Child↗

PubMed2004

Assessing a new response-microswitch combination with a boy with minimal motor behavior.

This study assessed whether a boy with profound multiple disabilities and minimal motor behavior could learn to use a new response-microswitch combination to control environmental stimulation. The response selected was a chin movement; a mechanical microswitch was set up for this response. The boy learned to use the microswitch, increasing the frequency of the chin response and the level of pleasant stimulation following such response. The performance was retained at a 2-mo. post-intervention check.

Adolescent↗