Immunoelectrophoretic Characterization of Insulin Monomers and Polymers

Insulin monomers and polymers were analysed by quantitative immunoelectrophoretic procedures. The Zn-insulin hexamer dissociated reversibly by dialysis against the Zn-free electrophoresis buffer. The Zn-insulin polymers showed precipitin reactions of partial identity. Monomeric salt-free insulin migrated as soluble immune complexes in the antiserum gel. The insulin monomer did not absorb the precipitating antibodies against the Zn-insulin polymers. Thus the polymer structure creates antigenic epitopes absent from the insulin monomer. As insulin is probably released from the β cells in the relatively stable form of Zn-insulin hexamers, selective monomer assays might underestimate the total content of immunoreactive insulin in the biological fluids. Electroimmunoassay of Zn-insulin immunoreactive antigens in human urine defines a normal reference range of 10–25 ng/ml.     

Growth in Rabbits during Alternate-Day Cortisone Injections: Near Normal Growth on Days without Cortisone

ABSTRACT. Longitudinal bone growth in rabbits during treatment with hydrocortisone was measured by means of Roentgen Stereophotogrammetric Analysis, RSA. This method allows accurate measurement of the distance between metallic markers inserted into long bones. Hydrocortisone was given in i.m. injections as single doses and as repeated doses, daily or every other day. Single injections of hydrocortisone resulted in three types of growth effect, depending on dosage. Low dosage (less than 4 mg/kg b.w.) produced no blunting of growth. Intermediate dosage (4–32 mg/kg b.w.) retarded growth during the first but not the second day after the injection. The effect of high dosage (64–128 mg/kg b.w.) lasted for two days. During daily treatment (4 and 16 mg/kg b.w.), growth decreased to a constant level. During alternate-day steroid injections with a double dose every other day, growth almost normalized during the steroid-free days. Average growth was significantly greater during alternate-day injections than during daily injections. It is concluded that alternate-day treatment has no unfavorable effect on growth so long as the interval between injections exceeds the duration of the growth effect of each single dose.     

Acquired pendular nystagmus: its characteristics, localising value and pathophysiology

Investigations were made of 16 patients with acquired pendular nystagmus and a further 32 cases reported in the literature were reviewed. Amongst our own patients two thirds had multiple sclerosis, almost one third a cerebrovascular accident or angioma and two had optic atrophy with squint. The nystagmus took forms which could be monocular or binocular, conjugate or disconjugate and could involve movements about single or multiple axes. Spectral analysis was used to characterise the amplitude and frequency of the movements and to estimate the degree of relationship (coherence) between movements of the two eyes or between movements of one eye about several axes. The oscillations ranged in frequency from 2·5 Hz to 6 Hz, with typical amplitudes between 3° and 5°. In a given patient all oscillations, regardless of plane, were highly synchronised. Somatic tremors of the upper limb, face and palate associated with the nystagmus were often at similar frequencies to the eye movement. The other ocular signs common to all our patients were the presence of squint with failure of convergence. Most patients also had skew deviation or internuclear ophthalmoplegia or both. The major oculomotor systems, that is, saccades, pursuit, optokinetic and vestibulo-ocular reflexes could be intact. It is inferred that the mechanism responsible for the pendular nystagmus lies at a level which is close to the oculomotor nuclei so that it can have monocular effects but is not part of the primary motor pathways. It is possible that this mechanism normally subserves maintenance of conjugate movement and posture of the eyes. The periodicity of the nystagmus is likely to arise from instability in a certain type(s) of neurone, for the associated somatic tremors have similar characteristics and yet involve very different neuronal muscular circuitry. Prognosis for cessation of the nystagmus is poor. In five patients with multiple sclerosis it was suppressed by intravenous hyoscine with, however, unacceptable subsequent side effects.     

Radiology of the orbital apex

The orbital apex, formed by the superior orbital fissure and optic canal, is the cross-road between the orbit and the intracranial structures. Pathological processes may extend intracranially via the superior orbital fissure and vice versa. In addition to intrinsic soft tissue lesions, various pathological processes may involve the surrounding osseous anatomy. Malignant lesions arising from adjacent structures or from haematogeneous metastasis may also infiltrate this region.     

急性淋巴细胞白血病(上)

急性淋巴细胞白血病是淋巴前体细胞异常引起的恶性疾病,儿童与成人均可能发生。儿童发病高峰2～5岁。有效治疗的稳步进展使本病在儿童中的治愈率80％以上,同时为新的治疗方案提供了良机,新方案将保留我们在白血病无病生存病例中获得的治疗经验,同时减轻当前强化治疗方案中的毒副作用。