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Biomedical subjects

U Sandbank

Publications and source records attributed to U Sandbank.

At least 37 records · Page 2Linked to original sources

Involvement of dorsal root ganglia in Fabry's disease.

Bouts of shooting pain along the extremities are common in the early stages of Fabry's disease. No pathological explanation has been advanced to clarify the mechanism of such pain. In the present case neuronal storage of glycolipid was confined to dorsal root ganglia neurones only. It is suggested that this may explain the shooting pain in Fabry's disease. In hereditary sensory radicular neuropathy, familial dysautonomia, and tabes dorsalis, changes in dorsal root ganglia cells cause similar clinical signs and thus it may be concluded that shooting pains in Fabry's disease may be caused by damage to dorsal root ganglia neurones.

Adult↗

Fatal peripheral neurolymphomatosis after remission of histiocytic lymphoma.

A 32-year-old woman with histiocytic lymphoma was in complete clinical remission after two courses of chemotherapy, when peripheral neuropathy developed fulminantly. Abnormalities included facial nerve paralysis, dysphagia, quadriparesis, myalgia, and incontinence. She died 10 days after onset of these symptoms. Postmortem examination revealed infiltration of peripheral nerves by lymphomatous cells with no involvement of meninges, brain, lymph nodes, or other organs. Differences in the blood-brain barrier of peripheral and central nervous system are suggested: The peripheral barrier may be more penetrable by malignant histiocytes or less permeable to cytotoxic drugs. Intrathecal chemotherapeutic drug instillation and irradiation may be beneficial.

Adult↗

Feedback inhibition of thymic secretory activity in mice treated by the thymic extract TP-1 (thymostimulin).

The ultrastructural changes occurring in the medullary epithelium of the thymus of young mice, as a result of repeated injections of thymic extract, TP-1 (thymostimulin) was investigated. After daily injection of TP-1 for 3 weeks, no changes in thymus architecture could be observed by light microscopy. However, by electron microscopy, specific changes were noticed in the epithelial cells. The secretory granules became dilated and engorged; diameter of granules in normal control thymus was approximately 200-250 nm, but reached 1000 nm in treated mice. Degenerative changes appeared in some of these granules, including myelin bodies, distorted configuration and fat droplets. Signs of involution of whole cells and presence of cellular debri within macrophages were observed. Acid phosphatase staining disclosed many lysosomes containing ingested granules. No such findings were observed in control untreated mice, or in mice treated by a heart extract similarly prepared to TP-1. All these findings can be taken as ultrastructural evidence for feedback inhibition of thymic secretory activity, in analogy to the changes occurring other feedback inhibited, peptide hormone secreting glands. The data indicate that (i) the thymus respond to feedback inhibitory stimuli, as other endocrine glands do; (ii)TP-1, the thymic extract under study, contains a physiologically significant thymic hormone, which, when introduced in high doses can exert specific feedback inhibition. This can be taken as an additional, new criterion for the definition of thymic hormones.

Animals↗

Permanent tetraplegia as a consequence of tetanus neonatorum. Evidence for widespread lower motor neuron damage.

It is generally believed that no permanent neurological damage is found among survivors of tetanus neonatorum. Newborns dying shortly after the onset of tetanus also lack significant neurological abnormalities. In adults a variety of neuromuscular lesions have been reported; however, a uniform pathological picture is absent. We report a case of a newborn with severe tetanus in whom striking evidence of anterior horn neuronal damage was documented, causing permanent nonprogressive tetraplegia. We suggest that the mechanism responsible for this lesion involves the retrograde axoplasmic flow of tetanus toxin reaching the spinal cord via nerve endings in the infected umbilical cord stump.

Atrophy↗

Combined treatment of Lewis lung carcinoma by tumor excision and levan.

A combined treatment modality including surgical excision and daily injections of high molecular levan seemed to be effective against Lewis lung carcinoma in C57BL mice. The inhibitory effect of levan on tumor growth in mice treated by resection of the primary tumor was demonstrated as follows: (1) recurrence of primary tumors was less in levan-treated mice compared to untreated animals; (2) metastases were less numerous in the levan-treated animals; (3) levan treatment partly prevented loss in body weight, and (4) it increased the survival rate. Recurrence of primary tumors appeared to be more efficiently inhibited by local levan treatment, while systemic (i.p.) administration was more effective than local treatment in preventing metastases. The mechanism of inhibition of tumor growth was related to accumulation of macrophages around the metastases.

Animals↗

Experimental limb dysmorphogenesis as a model of chemical injury response in undifferentiated embryonic tissues: a light and electron microscopical study.

A histopathological and ultrastructural analysis of the early stage of limb dysmorphogenesis from 1 hr to 48 hr, following citral administration is presented as a model for studying the reaction to injury of undifferentiated embryonic tissues. Early lesions such as cloudy swelling, hydropic degeneration, enlargement of the extracellular space and retraction of protoplasmic extensions were observed 1 hr after treatment, affecting both epiderm and mesenchyme of the limb. Few pyknotic cells were encountered during the early stages. Cell necrosis and autophagocytosis became more conspicuous at 12 hr post-injection. About the same time the first signs of healing were observed, charcterised by heterophagocytosis and return of mitotic activity. The epiderm being more differentiated, regenerates ad integrum and more rapidly than the mesenchyme. The evolution of these pathological events, which proceed in a spatio-temporal cascade, seem to reflect the pharmacokinetic gradient of the cell-teratogen interactions. The type of limb malformation will depend mainly on the extent of injury and/or healing of the mesenchymal mass, rather than on the injury and/or healing of the surface ectoderm. It is concluded that the reaction to chemical injury of undifferentiated tissues partially mimics the destructive and repair process in adult tissues, but differs in lacking some basic constituents such as oedema, monocyte exudation and granulation tissue formation.

Abnormalities, Drug-Induced↗

The role of macrophages and polymorphs in the levan-induced inhibition of Lewis lung carcinoma in C57BL mice.

High-mol.-wt levan injected locally inhibits the growth of Lewis lung carcinoma in C57BL mice. The inhibition is dependent on the number of tumour cells injected and on the dose of levan. The inhibition decreases tumour incidence and size as well as prolonging survival. The polysaccharide is most effective when injected daily beginning on the day of tumour-cell inoculation. Treatment begun on later dates is less effective. Treatment begun one day before tumour-cell inoculation enhances tumour growth. Histological studies showed that levan induces an intense polymorphonuclear (PMN) reaction followed by accumulation of vacuolated, levan-laden macrophages. Both PMN and activated macrophages seemed to have an inhibitory effect upon the growth of the tumour. The effector role of PMN was not explained by the histological study. Tumour cells in close contact with levan-laden macrophages appeared mostly necrotic. Administration of levan begun one day before tumour-cell inoculation produced a similar reaction, but the infiltrating cells did not appear to approach and damage the tumour cells.

Animals↗

Autoradiographic studies on the incorporation of tritiated uridine, leucine and methionine into Gomori-positive glia of rat hypothalamus.

The relative level of metabolic activity in Gomori-positive (Gp) glia was estimated by comparing the incorporation rates of 3H-uridine, 3H-leucine and 3H-methionine into the nuclear macromolecules of the glia, neurons, ependyma and subcommissural organ (SCO). The uptake of 3H-uridine by Gp glia was somewhat lower than that by neurons and SCO but higher than that by ependyma. The incorporation of 3H-leucine was about the same in all studied types of cells, except for a lower uptake by ependyma. The rate of 3H-methionine incorporation into Gp glia and SCO was higher than that into neurons and ependyma. The neuron: Gp glia ratios obtained in the present study (0.9--1.4) are more or less within the range of the neuron: cerebral glia ratios reported by others for newly synthesized molecules of RNA and proteins. The results suggest that Gp glia have a relatively high metabolic activity as compared to that in neurons and perhaps SCO.

Animals↗