Ordered conformation of succinoglycan in aqueous sodium chloride.

Succinoglycan samples ranging in weight-average molecular weight from 1.0 x 10(5) to 8.7 x 10(6) (in 0.1 M aqueous NaCl at 25 degrees C), prepared by ultrasonication of a native sample (Rheozan), followed by fractionation, were investigated by static light scattering, sedimentation equilibrium, and viscometry in 0.1 M aqueous NaCl at 25 degrees C where the polysaccharide assumes a certain ordered (helical) conformation. The measured radii of gyration and intrinsic viscosities showed the polysaccharide to behave like a semirigid chain in the aqueous salt. Their analysis based on the unperturbed wormlike chain yielded about 1500 nm-1 and 50 nm for the linear mass density and the persistence length, respectively. The former value was almost twice that expected for the single succinoglycan molecule, and thus it was concluded that the predominant molecular species of succinoglycan present in the aqueous salt is a double helix or an aggregate composed of paired single helices.

Lymphocytic adenohypophysitis: an immunohistochemical study.

Lymphocytic adenohypophysitis is a rare inflammatory disorder of the anterior pituitary gland. In some cases, there is evidence of concurrent autoimmune disease. We present the case of a 39-year-old woman who developed visual disturbance during the early postpartum period. Magnetic resonance imaging revealed an intrasellar mass with suprasellar extension. Study of the tumor tissue showed diffuse infiltration of the entire pituitary gland by lymphocytes and plasma cells. Immunohistochemical examination revealed that the majority of the infiltrating lymphocytes were T cells that might have modulated the immunoreaction to the anterior pituitary gland. We suggest that the disorder is related to cell-mediated immunity as well as humoral immunity.

[The changes of intracranial pressure after shunt surgery: measurements of pre- and postshunt ventricular fluid pressure with an implanted telemetric ICP sensor].

The changes of intracranial pressure (ICP) after shunt surgery are not fully known. We measured ventricular fluid pressure (VFP) in 10 hydrocephalic patients before and after ventriculoperitoneal shunts. VFP was monitored with an implanted telemetric ICP sensor placed in the shunt system equipped with an on-off valve. Recordings with the valve closed were used as preshunt VFP measurements. In serial montorings, two patterns of VFP changes were recognized. One was an immediate decrease of VFP to a steady state after the surgery. The other was a gradual decrease to constant level within several days. After reaching steady states, postshunt VFP showed around OmmHg in the supine position in a half of the patients. Head elevation (20 - 60 degrees) allowed VFP to decrease to -10(-)-25 mmHg in 9 out of 10 patients. These measurements were irrespective of the pressure range of peritoneal catheters. Changes of postshunt VFP seemed to be non-physiological, despite the improvement of symptoms brought about by the surgery. B-wave seen frequently before surgery disappeared in all but two patients. There were two types of shunt malfunction found in follow-up periods. Hypofunctions caused by a disconnection of the peritoneal catheter from the reservoir, and an intraperitoneal cyst were detected by VFP monitoring. Overdrainage of cerebrospinal fluid (CSF), however, was not disclosed by this monitoring. From these results, this ICP sensor was considered to be useful to know the perioperative VFP changes in hydrocephalic patients. And the pathogenesis of B-wave was strongly suspected to be attributable to the disturbance of CSF circulation.

Temporary network formation of hyaluronate under a physiological condition. 1. Molecular-weight dependence.

The dynamic shear moduli at various frequencies and stress growth after the sudden start of steady shear were measured for 1% HA (hyaluronic acid) solutions with different molecular weights. From the results of the zero shear viscosity, eta 0, the steady shear compliance, J 0e, and delta eta defined as delta eta = eta 0 - eta a (infinity), where eta a (infinity) is the apparent viscosity at the steady state, it was shown that the molecular mechanism of flow of 1% HA solutions was classified into four regions with respect to molecular weight: (I) the viscosity-average molecular weight Mv less than 35 X 10(4), HA chains are dispersed molecularly in solution; (II) 35 X 10(4) less than Mv less than 100 X 10(4), the polymer chains form a weak entanglement network observed only through eta 0; (III) 100 X 10(4) less than Mv less than 160 X 10(4), the network is strengthened with increasing molecular weight and becomes detectable through both eta 0 and J 0e and also through the overshoot phenomenon; and (IV) 160 X 10(4) less than Mv, the network is "saturated" or "completed" dynamically. This is the conjecture presented for the first time by the present work.

Correlation between the antitumor activity of a polysaccharide schizophyllan and its triple-helical conformation in dilute aqueous solution.

Eight samples of a polysaccharide schizophyllan ranging in weight-average molecular weight Mw (in water) from 5 x 10(3) to 1.3 x 10(5) were prepared and their antitumor activity (expressed in terms of the tumor inhibition ratio) against Sarcoma 180 ascites, intrinsic viscosities [eta], and gel-filtration chromatograms in aqueous solution were determined. The tumor inhibition ratio was essentially unity for samples with Mw higher than 9 x 10(4), but reduced to zero or even to a negative value when Mw was lower than 10(4). The [eta] data combined with the chromatographic data showed that above Mw approximately 9 x 10(4) the predominant species of schizophyllan in aqueous solution is the previously found rigid triple helix, whereas below Mw approximately 9 x 10(4) both triple helices and single chains coexist in the solution and the fraction of triple helices decreases monotonically to zero as Mw is decreased to 5 x 10(3). From these findings it was concluded that the antitumor potency of schizophyllan in water is related to the amount of triple helices relative to that of single chains.