Depolarization of light in tissue phantoms - effect of a distribution in the size of scatterers

We show that the depolarization behavior of light on propagation through a sample having a mixture of suspension of monodisperse polystyrene microspheres of two different sizes (mean diameter 0.11microm and 1.08 microm) is dominated by the smaller of the two scatterers. In contrast the estimates for the anisotropy parameter (g) for this sample, obtained from goniophotometric measurement, are observed to be closer to the value corresponding to the larger of the two scatterers. These results imply that the depolarization behavior of light in biological tissue (having a distribution of scatterer size) would be different from that of a matched monodisperse scattering sample having the same value of anisotropy parameter (g) and optical thickness (tau = micros x d, micros is scattering coefficient and d being the physical thickness).

2-(2-Naphthyloxy)acetate derivatives. II. A new class of antiamnesic agents

The title compounds, 4-(2-naphthyloxymethylcarbonyl)morpholine, C(16)H(17)NO(3), (I), and 4-methyl-1-(2-naphthyloxymethylcarbonyl)piperazine, C(17)H(20)N(2)O(2), (II), are potential antiamnesics. The morpholine ring in (I) and the piperazine ring in (II) adopt chair conformations. In (I), the molecules are linked by weak intermolecular C-H.O interactions into chains that have a graph-set motif of C(10), while in (II), the molecules are linked by weak intermolecular C-H.O interactions that generate two C(7) graph-set motifs. The dihedral angle between the naphthalene moiety and the best plane through the morpholine ring is 20.62 (4) degrees in (I), while the naphthalene moiety is oriented nearly perpendicular to the mean plane of the piperazine ring in (II).

A case of chronic osteomyelitis due to Arcanobacterium hemolyticum

We report here a case of chronic osteomyelitis, which appeared to be tubercular, from the clinical, radiological and histopathological points of view. But on culture an unusual bacterium, Arcanobacterium hemolyticum, was isolated and the patient responded to treatment with clindamicin, prescribed in accordance to the sensitivity reports.

Cross-sectional area of the lumbar back muscles as a function of torso flexion

OBJECTIVE

Quantification of the maximum anatomical cross-sectional area of the lumbar back muscles as a function of torso flexion angle and development of prediction equations as a function of torso flexion and anthropometric measures.

BACKGROUND

Cross-sectional areas of the lumbar back muscles used as inputs into biomechanical models have traditionally been derived from subjects lying in the neutral supine posture. However, it is known that the cross-sectional area of muscle is altered as the torso angle changes.

DESIGN

Experimental design consisted of a two-factor multivariate analysis of variance on the cross-sectional area of the lumbar torso muscle across the lumbar levels, as a function of gender and torso angle. Hierarchical linear regression was utilized to assess the association between cross-sectional area and individual and torso posture characteristics.

METHOD

Axial MRI scans, through and parallel to each of the lumbar intervertebral discs at four torso flexion positions were obtained from subjects in a lateral recumbent posture. Cross-sectional areas were quantified and converted into anatomical cross-sectional areas utilizing known fascicle orientations.

RESULTS

The maximum anatomical cross-sectional area was located between the L(3)/L(4) and L(4)/L(5) level in the neutral posture. The anatomical cross-sectional areas at the L(4)/L(5) and L(5)/S(1) decreased during torso flexion, however, the percent change varied as a function of the individual level. The majority of the anatomical cross-sectional area variability was explained by gender and body mass. Lumbar curvature explained a larger proportion of the anatomical cross-sectional area variability at the lower lumbar levels than at the higher lumbar levels.

CONCLUSIONS

The maximum anatomical cross-sectional area of the lumbar back muscles occur at the neutral torso posture and did not decrease as a function of torso flexion. When using maximum anatomical cross-sectional area or specific lumbar level anatomical cross-sectional areas, it appears necessary to account for gender and body mass. At the lower lumbar levels, knowledge of spinal curvature plays an increasing role in the estimation of the size of the lumbar torso muscle cross-sectional area.

RELEVANCE

This research indicates the lower lumbar level trunk muscle anatomical cross-sectional area decrease as torso flexion increases, however, the maximum lumbar trunk muscle anatomical cross-sectional area does not vary as a function of torso flexion. Accounting for gender, body mass, torso characteristics and lumbar curvature may help increase accuracy of anatomical cross-sectional area prediction, as well as muscle force predictions from biomechanical models.

Awareness of brain death and organ transplantation among select Indian population

BACKGROUND

With the improvement in transplant technology major organ transplantation is gradually becoming the treatment of choice in many conditions. The present study assesses the awareness of the concepts of brain death and organ transplantation among public.

METHODS

Six hundred thirty six select populations, which included office-goers of Delhi, class 12th school children of a reputed public school and villagers, were interviewed to assess their knowledge in various aspects of brain death and organ transplantation.

RESULTS

There was widespread acceptance of organ transplantation among this population. The most alarming feature was that the awareness of the concept of brain death and its importance for organ donation was extremely low. Only small number of individuals were aware that brain death is legal in India. Awareness about brain death was especially low among villagers.

CONCLUSIONS

Education about various aspects of brain deaths, its immense importance for organ donation and legality of brain death in India needs to be highlighted.

Primary spinal extradural hydatid cyst

We report a rare case of spinal cord compression caused by primary multiple extradural hydatid cysts.

Combinatorial synthesis of unsymmetrical secondary amines. Application to arylethanolamines, arylpropanolamines and aryloxypropanolamines

Combinatorial libraries of unsymmetrical secondary amines: arylethanolamine, arylpropanolamines and aryloxypropanolamines [1], in particular have been synthesized by four different routes using styrenes, aldehydes, hydroxyaromatic acids and bromoaliphatic acids. The structurally diverse libraries were generated in parallel format using solid phase methodology. The compounds corresponding to prototype I-IV were obtained in high yields and purities.

Pulmonary arteriovenous malformations: effect of embolization on right-to-left shunt, hypoxemia, and exercise tolerance in 66 patients

OBJECTIVE

This study assessed the effect and safety of percutaneous transcatheter coil embolization of pulmonary arteriovenous malformations.

MATERIALS AND METHODS

In 58 (88%) of 66 patients, all malformations with feeding vessels greater than or equal to 3 mm in diameter were embolized with steel coils. Arterial oxygen saturation at rest and exercise, intrapulmonary right-to-left anatomic shunt fraction ((99m)Tc-macroaggregate injection), maximum exercise capacity (incremental work rate test), and pulmonary function were measured before and after embolization. Complications were analyzed.

RESULTS

Three categories of patients were identified. Patients in group 1 (27%) had complete occlusion of all angiographically visible pulmonary arteriovenous malformations; patients in group 2 (61%) had complete occlusion of all malformations with feeding vessels greater than or equal to 3 mm in diameter, but with smaller lesions persisting; and patients in group 3 (12%) had incomplete embolization, with feeding vessels greater than or equal to 3 mm in diameter remaining. The mean right-to-left shunt after embolization was least in group 1 (7%), intermediate in group 2 (10%), and greatest in group 3 (19%). Arterial oxygen saturation and right-to-left shunt fraction returned to normal levels (>96% and <3.5%, respectively) in 33% of patients. A significant improvement occurred after embolization in carbon monoxide diffusing capacity per unit of alveolar volume and in exercise capacity in 16 and 10 patients, respectively. In 93 procedures, 12 complications (13%) occurred.

CONCLUSION

Coil embolization of pulmonary arteriovenous malformations is effective in reducing right-to-left anatomic shunt fraction and in improving arterial oxygenation. Coil embolization of pulmonary arteriovenous malformations is well tolerated and has a low complication rate.

Study of yoga asanas in assessment of pulmonary function in NIDDM patients

Certain yoga asanas if practiced regularly are known to have beneficial effects on human body. These yoga practices might be interacting with various, somato-neuro-endocrine mechanisms to have therapeutic effects. The present study done in twenty four NIDDM patients of 30 to 60 year old, provides metabolic and clinical evidence of improvement in glycaemic control and pulmonary functions. These middle-aged subjects were type II diabetics on antihyperglycaemic and dietary regimen. Their baseline fasting and postprandial blood glucose and glycosylated Hb were monitored along with pulmonary function studies. The expert gave these patients training in yoga asanas and were pursed 30-40 min/day for 40 days under guidance. These asanas consisted of 13 well known postures, done in a sequence. After 40 days of yoga asanas regimen, the parameters were repeated. The results indicate that there was significant decrease in fasting blood glucose levels (basal 190.08 +/- 90.8 in mg/dl to 141.5 +/- 79.8 in mg/dl). The postprandial blood glucose levels also decreased (276.54 +/- 101.0 in mg/dl to 201.75 +/- 104.1 in mg/dl), glycosylated hemoglobin showed a decrease (9.03 +/- 1.4% to 7.83 +/- 2.6%). The FEV1, FVC, PEFR, MVV increased significantly (1.81 +/- 0.4 lt to 2.08 +/- 0.4 lt, 2.20 +/- 0.6 lt to 2.37 +/- 0.5 lt, 3.30 +/- 1.0 lt/s to 4.43 +/- 1.4 lt/s and 64.59 +/- 25.7 lt min to 76.28 +/- 28.1 lt/min respectively). FEV1/FVC% improved (85 +/- 0.2% to 89 +/- 0.1%). These findings suggest that better glycaemic control and pulmonary functions can be obtained in NIDDM cases with yoga asanas and pranayama. The exact mechanism as to how these postures and controlled breathing, interact with somato-neuro-endocrine mechanism affecting metabolic and pulmonary functions remains to be worked out.

Mammary tuberculosis: report on 52 cases

Fifty two cases of tuberculosis of the breast encountered over a 15 year period and accounting for 3% of all breast lesions are reported. The classic presentation was a breast lump with associated sinus in 39%, isolated breast lump in 23%, sinus without lump in 12%, and tender nodularity in 23% of the patients. Associated axillary lymphadenopathy was found in 41%. Diagnosis was confirmed by fine needle aspiration cytology or histology in all the cases and antitubercular therapy formed the mainstay of treatment.

A preliminary report on characterization and identification of non tuberculous mycobacteria (NTM) on the basis of biochemical tests and protein / isoenzyme electrophoretic patterns

PURPOSE

To assess the usefulness of protein electrophorograms and protein zymodemes in the identification and characterization of non tuberculous mycobacteria (NTM).

METHODS

Cell free extracts (CFEs) from 22 mycobacterial isolates belonging to slow growing and other clinically relevant species were included in the study. The strains isolated from the environment were identified on the basis of their standard biochemical tests; pigmentation and growth characters. The CFEs were electrophoresed and stained for proteins and esterases.

RESULTS

Most of the isolates identified on the basis of biochemical tests exhibited characteristic protein and esterase pattern for M. scrofulaceum, M. avium and M. xenopi. Others showed variations in their proteins and esterase pattern though they were identified as M. scrofulaceum, M. avium and M. xenopi.

CONCLUSIONS

Based on these studies it appears that because of variability in the protein and isoenzyme patterns of NTM, it may be advisable to use them along with biochemical tests and other tests for identifying and characterizing the different mycobacterial species belonging to slow growers.

Carbon fibres and plasma-preserved tendon allografts for gap repair of flexor tendon in bovines: clinical, radiological and angiographical observations

Twenty-four tenorrhaphies were performed at the mid-metatarsal region in 12 crossbred calves under xylazine-ketamine spinal analgesia. A 2.5-cm long gap was created in the superficial digital flexor (SDF) tendon and immediately repaired with carbon fibres in the animals of group I and with plasma-preserved tendon allografts in group II. Clinical examination revealed a slight increase (P > 0.05) in rectal temperature, heart and respiratory rate for 2-4 days postoperation in both groups. Milder pain and exudation as well as earlier restoration of tendon gliding movements and weight bearing were observed in group I as compared to group II. Air-tendogram in the carbon fibre group on day 30 revealed restoration of continuity across the defect of the tendon. whereas, in the allograft group, a dense homogeneous swelling was seen along the flexors. Regression of peritendinous adhesions and swelling at the reconstructed site at later stages was seen in both groups. Angiography showed hypervascularization at the reconstructed site on day 14 in the carbon fibre group, however, in the allograft group the site appeared to be relatively avascular. On days 30 and 90, blood vessels were normally organized in both groups.

Spine loading characteristics of patients with low back pain compared with asymptomatic individuals

STUDY DESIGN

Patients with low back pain and asymptomatic individuals were evaluated while performing controlled and free-dynamic lifting tasks in a laboratory setting.

OBJECTIVE

To evaluate how low back pain influences spine loading during lifting tasks.

SUMMARY OF BACKGROUND DATA

An important, yet unresolved, issue associated with low back pain is whether patients with low back pain experience spine loading that differs from that of individuals who are asymptomatic for low back pain. This is important to understand because excessive spine loading is suspected of accelerating disc degeneration in those whose spines are damaged already.

METHODS

In this study, 22 patients with low back pain and 22 asymptomatic individuals performed controlled and free-dynamic exertions. Trunk muscle activity, trunk kinematics, and trunk kinetics were used to evaluate three- dimensional spine loading using an electromyography- assisted model in conjunction with a new electromyographic calibration procedure.

RESULTS

Patients with low back pain experienced 26% greater spine compression and 75% greater lateral shear (normalized to moment) than the asymptomatic group during the controlled exertions. The increased spine loading resulted from muscle coactivation. When permitted to move freely, the patients with low back pain compensated kinematically in an attempt to minimize external moment exposure. Increased muscle coactivation and greater body mass resulted in significantly increased absolute spine loading for the patients with low back pain, especially when lifting from low vertical heights.

CONCLUSIONS

The findings suggest a significant mechanical spine loading cost is associated with low back pain resulting from trunk muscle coactivation. This loading is further exacerbated by the increases in body weight that often accompany low back pain. Patient weight control and proper workplace design can minimize the additional spine loading associated with low back pain.