Potential increase in photosynthetic response of taro (Colocasia esculenta L.) to photon flux density and elevated CO2

Aim: The present study was undertaken to study the net photosynthetic rate (Pn), stomatal conductance (gs) and intercellular CO2 (Ci) in five eddoe and four dasheen type taro genotypes under ambient and elevated CO2 , and subjected to different photon flux densities. Methodology: The critical evaluation of Pn was assessed at different photosynthetic photon flux densities (PPFDs) viz., 200, 400, 600, 800, 1000, 1200 and 1500 µmol m-2 hr-1 under ambient CO2 (400 ppm) and at saturation PPFD (1500 µmol m-2 hr-1) at short-term (ten min) exposure of leaves to elevated CO2 (eCO2; 600, 800 and 1000 ppm) at 30oC using portable photosynthesis system LI-6400, LICOR, USA in a controlled-climate cuvette system. Results: The Pn in the leaves of nine taro genotypes persistently augmented upon short-term (10 min) exposure to eCO2 concentrations which ranged between 400 ppm and 1000 ppm. Taro genotypes exhibited 61.80 – 113.3% hike in Pn at eCO2 (1000 ppm) as compared to ambient CO2 (400 ppm). However, the per cent increase in Pn at eCO2 for every 200 ppm between 400 to1000 ppm significantly declined (4.4-18.4%) at 1000 ppm CO2. The differences in gs were statistically significant across taro genotypes (P>0.001) and CO2 concentrations (P>0.001). Further, the Ci was also found to increase constantly at eCO2 concentrations (400 ppm to 1000 ppm). However, there was significant reduction (16.2 - 31.3%) in Ci for every 200 ppm between 400-1000 ppm. Interpretation: Results of the study revealed that the genotypes Muktakeshi, Sree Pallavi and Telia are promising in the context of climate change as they significantly responded to eCO2 concentrations. Response mechanism to eCO2 need to be elucidated.

Role of clinical neurophysiological tests in evaluation of erectile dysfunction in people with spinal cord disorders.

BACKGROUND: While erectile dysfunction is frequent among people with disorders of the spinal cord, the role of various clinical neurophysiological tests in assessment is not clear. AIMS: To study the role of clinical neurophysiological investigations in assessing erectile dysfunction among men with spinal cord disorders. SETTING: National Institute of Mental Health and Neurosciences, India. DESIGN: Survey. MATERIALS AND METHODS: Subjects with a score of 21 or less on the International Index of Erectile Function-5 were classified as with erectile dysfunction and with a score of more than 21 as without erectile dysfunction. Clinical neurophysiological studies done were Sympathetic Skin Response from limbs, posterior tibial sensory evoked potential, pudendal sensory potential and bulbocavernous reflex. STATISTICAL ANALYSES: Chi-square test. RESULTS: Among 40 subjects 26 had erectile dysfunction. The frequency of abnormalities in clinical neurophysiological studies were: pudendal sensory evoked potentials--16, posterior tibial sensory evoked potentials--26, bulbocavernous reflex--5, sympathetic skin response from sole--24 and, sympathetic skin response from palm--18. Significant associations were noted between erectile dysfunction and abnormal pudendal sensory evoked potentials (P=0.0479), and absent sympathetic skin response from palm (P=0.0279) and sole (P< 0.001). There was no correlation between erectile dysfunction and posterior tibial sensory evoked potentials (P=0.133) or bulbocavernous reflex (P=0.418). Sympathetic skin response from sole was most sensitive (80.8%) and had best positive (87.5%) and negative predictive (68.8%) values. The specificity of these three tests was 78.6%. CONCLUSIONS: Sympathetic skin response from the sole of the foot was the most sensitive and specific clinical neurophysiological test for erectile dysfunction in spinal cord disorders.

Stroke rehabilitation : traditional and modern approaches.

The recovery from stroke is often slow and incomplete, leading to partial or complete loss of locomotion, activities of daily living (ADL), cognition and communication skills. Aim of stroke rehabilitation is to reduce the disabilities and enable the patient to return to community, which is achieved by joint efforts of physicians, physiotherapists, occupational therapists, speech therapists, nurses, social workers and psychologists. Rehabilitation of a stroke patient begins as soon as any impairment is perceived and comprises traditional exercise programmes and neuropsychological approaches with the primary aim of restoring mobility of patient. It also deals with issues related to dysphagia, bowel and bladder care, shoulder dislocation, pressure sores, and prevention of deep venous thrombosis. A good rehabilitation programme helps in promoting natural recovery, preventing complications due to disabilities and adapting to disabilities.

Pneumatic splints: fabrication and use in neurorehabilitation.

Asymmetrical tone and weakness in antagonistic muscles often result in misalignment of joint, contractures and deformities. Traditional static splints used to prevent these complications are expensive, have to be custom made and cannot be used when deformities are marked. Authors describe fabrication and use of pneumatic splints, which are economic, safe and easy to apply. These splints have wide application in the management of common medical problems in neurological rehabilitation like hypotension, edema, pain, spasticity and early deformities.

Neurogenic heterotopic ossification : a diagnostic and therapeutic challenge in neurorehabilitation.

Heterotopic ossification (HO) is an important cause of restriction in range of movements and secondary motor disability following neurotrauma, orthopaedic interventions and burns. It has not received focussed attention in non-traumatic neurological disorders. In a prospective study of 377 patients, on medical problems in neurological rehabilitation setting, 15 subjects (3.97%) had neurogenic heterotopic ossification. Their clinical diagnosis was: transverse myelitis (7), neurotuberculosis (4), traumatic myelopathy (2) and stroke (2). Hip (10), knee (4) and elbow joints (1) were involved. The risk factors included urinary tract infection (15), spasticity (6), pressure sores (13) and deep venous thrombosis (DVT) (6). The initial diagnosis was often other than HO and included DVT (3), haematoma (2) and arthritis (2). ESR and serum alkaline phosphatase levels were elevated in all but one subject. The diagnosis of HO was established using X-rays, CT Scan and three-phase bone scan. Following treatment with non-steroidal anti-inflammatory drugs, the range of motion improved in only four patients. HO resulted in significant loss of therapy time during rehabilitation. High index of suspicion about this complication is necessary for early diagnosis and prompt intervention.

Non-traumatic acute rhabdomyolysis.

A boy developed sudden severe generalized muscle stiffness, bulbar weakness and passed dark coloured urine. Laboratory tests revealed marked elevation of creatinine kinase(CK) levels and myoglobinuria. Histopathology of quadriceps muscle showed features of acute rhabdomyolysis. Patient made complete clinical recovery over a period of three weeks and CK returned to normal level. The possible aetiologies of non-traumatic rhabdomyolysis are discussed and the relevant literature reviewed.

Paget--Schroetter's syndrome.

Primary thrombosis of the subclavian axillary veins is known as Paget-Schroetter's syndrome. A 35 year old male with classical features of this syndrome is being reported. Antecubital venogram showed bilateral subclavian thrombosis.