The contribution of the three columns of the spine to rotational stability. A biomechanical model

A function of the spine as a structural column is its ability to resist torsion. The goal of this study was to evaluate the contribution of the columns of the spine to torsional rigidity. Ten human cadaver spines were harvested and frozen. The specimens, consisting of segments from T11 to S1, were subjected to torsional loads of up to 20 N-m. Rotation was recorded throughout the loading cycle. The columns of the spine were destroyed at the L2-3 interspace in a predetermined fashion and loading was repeated. The data were plotted as torsion versus rotation in degrees. The curves of each loading cycle were compared and the ratios of the intact and compromised specimens were calculated. The contribution of each column of the spine to torsional rigidity was determined. In an intact lumbar spine, the anulus was the most effective structure in resisting torsion. Experience gained in this study supports the following conclusion: Flexion-distraction injuries of the thoracolumbar and lumbar spine involving soft tissue destruction of the anterior column and anulus result in rotational instability.

Failure of long-term cyproheptadine therapy in lowering growth hormone levels in acromegaly

Basal and post-glucose growth hormone (GH) responses were evaluated in 10 acromegalics receiving cyproheptadine (cypro) 4 mg 6 hourly at 2 and 21 days after initiating therapy. Of the 10 patients, six had macroadenomas with varying degree of suprasellar extensions, one a microadenoma and three had persistent hypersomatotropism despite pituitary adenomectomy due to residual tumour. The basal and post-glucose GH showed no significant change in all, except one with a pituitary microadenoma. His GH was reduced from 680 to 108 mU/L on the second and 82 mU/l on the 21st day of cypro therapy. These data do not suggest any therapeutic role of cypro in the management of acromegaly.

Estimation of plasma and urinary catecholamines in Guillain-Barré syndrome

Serial estimation of plasma nor-epinephrine (PNE), 24 hours urinary vanilmandelic acid (VMA) and plasma cortisol was made in 25 adult patients of Guillain-Barré syndrome. Healthy adult age and sex matched volunteers served as controls. The mean level of PNE, VMA and plasma cortisol in controls was 1.07 +/- 0.50 ng/ml, 2.81 +/- 1.18 mg/24 hours and 12.9 +/- 3.10 micrograms/100 ml, respectively. In cases of Guillain-Barré syndrome with autonomic dysfunction the mean level of PNE, VMA and plasma cortisol was 3.34 +/- 2.47 ng/ml, 7.98 +/- 5.71 mg/24 hours and 27.25 +/- 4.94 micrograms/100 ml on the day of admission while in cases of Guillain-Barré syndrome without autonomic dysfunction it was 1.09 +/- 0.32 ng/ml, 3.04 +/- 2.22 mg/24 hours and 11.8 +/- 4.2 micrograms/100 ml, respectively. An increase in circulating PNE, VMA and plasma cortisol was demonstrated in patients of Guillain-Barré syndrome with autonomic dysfunction presenting as hypertension and tachycardia. The maximum rise of 284% (PNE) and 253% (VMA) occurred at the height of paralysis. The elevated levels fell to near control values at the time of significant recovery, and glucose tolerance tests improved. It is suggested that increased levels of catecholamines and cortisol contributed to the development of dysautonomia as these levels were within normal limits in patients of Guillain-Barré syndrome without autonomic dysfunction.

Bisalbuminemia in nephrotic syndrome (a case report)

A rare case of bisalbuminemia in a patient with minimal lesion glomerulonephritis (MLGN) in which the course of the disease and therapeutic response to steroid were typical of minimal lesion glomerulonephritis, is presented and literature reviewed.