Effect of stimulation of the dorsal aspect of the cervical spinal cord on ’Iocal cerebral blood flow and EEG in the cat

Abstract

Currently there is considerable interest in electrical stimulation of the dorsal aspect of the cervical spinal cord as a potentially effective therapy for persistent vegetative patients. The authors assessed change in the local cerebral blood flow (LCBF) and electroencephalogram (EEe) in the cat following spinal cord stimulation (SCS). In 31 adult cats under isoflurane anesthesia, an electrode for SCS was introduced epidurally to the midline of the C2-C3 segment. Stimulation was performed at 25 Hz and 0.7 msec for30 min. These animals were divided into five groups by the voltage: (1) 2V (n = 7), (2) 4V (n = 7), (3) 6V (n = 7), (4) 4V with intravenous injection of muscarinic cholinergic agents - atropine sulfate (n =5), and (5) sham-operated control (n = 5) without stimulation. LCBF was measured by laser Doppler flowmetry through bilateral small burr holes at the parietal area during and 60 min after stimulation. At 2~ LCBF increased only during SCSI then returned to the pre-stimulated level, while the increase continued until the end of the experiment at 4Vand 6V. The increase in LCBF was not affected by atropine sulfate. EEe showed spike and wave or polyspikes after SCS in two animals of the 6V group, but not in the 2V and 4V groups, and moreover a moderate increase ofthe background activity at only 4V. The present data suggested that SCS at 4Vcan provide the appropriate microcirculatory enhancement with less harmful influence which continues to increase 30 min after SCSI although the exact mechanism should be elucidated continuously. Within the limitation of animal experiments, this study could provide the logical basis for determining the condition of SCS. [Neural Res 2000; 22: 386-392]     

Spinal root avulsion-induced upregulation of osteopontin expression in the adult rat spinal cord

Osteopontin (OPN) is a secretory adhesive glycoprotein that is expressed in various tissues and plays a role in inflammation and tissue repair. It has been suggested that OPN plays a role in inflammation and wound healing after spinal cord injury; however, the expression of OPN and its function in the spinal cord under normal conditions and following spinal motoneuron injury have not been well characterized. Here we examined the expression of OPN mRNA before and after spinal root avulsion. OPN mRNA was detected at a low level in the normal spinal cord in a Northern blot analysis, but dramatically increased following avulsion. In situ hybridization and immunohistochemical studies demonstrated that OPN was present only in a subset of spinal motoneurons before avulsion. After avulsion, the number of OPN-expressing motoneurons increased, although the total number of motoneurons was reduced. OPN expression also became apparent in activated microglia/macrophages and astrocytes. These data suggest that the upregulation of OPN after spinal root avulsion is involved in two events, the protection of neurons and the post-traumatic inflammatory response in microglia/macrophages and astrocytes.     

Transplanted hematopoietic stem cells from bone marrow differentiate into neural lineage cells and promote functional recovery after spinal cord injury in mice

Recovery in central nervous system disorders is hindered by the limited ability of the vertebrate central nervous system to regenerate lost cells, replace damaged myelin, and re-establish functional neural connections. Cell transplantation to repair central nervous system disorders is an active area of research, with the goal of reducing functional deficits. Recent animal studies showed that cells of the hematopoietic stem cell (HSC) fraction of bone marrow transdifferentiated into various nonhematopoietic cell lineages. We employed a mouse model of spinal cord injury and directly transplanted HSCs into the spinal cord 1 week after injury. We evaluated functional recovery using the hindlimb motor function score weekly for 5 weeks after transplantation. The data demonstrated a significant improvement in the functional outcome of mice transplanted with hematopoietic stem cells compared with control mice in which only medium was injected. Fluorescent in situ hybridization for the Y chromosome and double immunohistochemistry showed that transplanted cells survived 5 weeks after transplantation and expressed specific markers for astrocytes, oligodendrocytes, and neural precursors, but not for neurons. These results suggest that transplantation of HSCs from bone marrow is an effective strategy for the treatment of spinal cord injury.     

Cyclophosphamide-using nonmyeloablative allogeneic cell therapy against renal cancer with a reduced risk of graft-versus-host disease.

PURPOSE: Much attention has been paid to nonmyeloablative allogeneic stem cell transplantation for the treatment of renal cancer. We recently proposed a cyclophosphamide-using nonmyeloablative cell therapy in which donor lymphocyte infusion (DLI) was carried out after the tolerance induction to donor cells. In considering the clinical application of the cyclophosphamide-using cell therapy, attempts to reduce graft-versus-host disease (GVHD) are crucial. The aim of the present study was to modify the cyclophosphamide-using cell therapy to reduce the risk of GVHD while preserving the antitumor activity against renal cancer. EXPERIMENTAL DESIGN: We assessed whether a delay in performing DLI from day 1 to day 5 after the cyclophosphamide treatment could reduce the risk of GVHD while preserving antitumor activity against RENCA, a murine carcinogen-induced renal cell carcinoma, in the cyclophosphamide-using cell therapy. RESULTS: Regarding the in vivo antitumor effect, there was no difference between DLI on day 1 and day 5 after the cyclophosphamide treatment, whereas the histologic findings of the small intestine showed that the cyclophosphamide-using cell therapy with DLI on day 5 decreased the risk of GVHD. In addition, the acquired immunity against RENCA was also observed in the RENCA-rejected mice that had been treated with DLI on day 5. CONCLUSIONS: Our results show that a delay in DLI during cyclophosphamide-using nonmyeloablative cell therapy can dissociate graft-versus-tumor effects from GVHD by reducing the risk of GVHD.     

Therapeutic results using high-dose-rate intracavitary irradiation in cases of cervical cancer

A comparison of the 5-year relative survival rates has been made between cases of cancer of the uterine cervix treated with 226Ra low-dose-rate intracavitary irradiation and those treated with 60Co high-dose-rate intracavitary irradiation (using the remote afterloading system, RALS). External irradiation using LINAC was also administered in both groups. The 5-year relative survival rates of the low-dose-rate cases were 82.6, 55.4, 49.0, and 18.2% in stage I, II, III, and IV cases, respectively, whereas they were 97.4, 55.1, 56.8, and 29.0% in the respective high-dose-rate cases. The differences between the two groups were not statistically significant. Delayed radiation complications of the rectum were frequent in both groups (approximately 14%) and those of the urinary bladder were somewhat less frequent (approximately 8%). The incidence of such complications did not differ significantly between the two groups.     

Clinicl Significance of Mesangial IgM Deposits in Minimal Change Nephrotic Syndrome

The clinicopathologic features and the response to corticosteroid therapy were compared in 9 patients with minimal change nephrotic syndrome (MCNS) and diffuse mesangial IgM deposits (Group I) and in 32 of those without IgM deposits (Group II). However, serum IgM levels in Group I in both relapse and remission were significantly higher than those of Group II and controls (p<0.001). In Group I mesangial IgM deposits were diffuse in 9 (100%), mesangial C_1q was present in 4, IgA and fibrinogen were each observed in 1, respectively. Electron dense deposits in the mesangium were also present in 2 to 5 patients in Group I. No significant differences were found between the two groups in age of onset, sex ratio, laboratory data except for serum IgM level, duration before biopsy, follow-up periods, outcome, and response to steroid therapy. Our data suggest that a more severe degree of either impairment of mesangial clearance of IgM or overproduction of IgM may be involved in patients with MCNS and mesangial IgM deposits but that these patients could not be considered a distinct group of patients.     

Dehydrotrametenolic acid induces preadipocyte differentiation and sensitizes animal models of noninsulin-dependent diabetes mellitus to insulin

We recently discovered that the triterpene acid compound dehydrotrametenolic acid promotes adipocyte differentiation in vitro and acts as an insulin sensitizer in vivo. This natural product has been isolated from dried sclerotia of Poria cocos WOLF (Polyporaceae), a well-known traditional Chinese medicinal plant. We examined the effects of dehydrotrametenolic acid on plasma glucose concentration in obese hyperglycemic db/db mice. Dehydrotrametenolic acid can reduce hyperglycemia in mouse models of noninsulin-dependent diabetes mellitus (NIDDM) and act as an insulin sensitizer as indicated by the results of the glucose tolerance test. These terpenoids and thiazolidine type of antidiabetic agents such as Ciglitazone, although structurally unrelated, share many biological activities: both induce adipose conversion, activate peroxisome proliferator-activated receptor gamma (PPAR gamma) in vitro, and reduce hyperglycemia in animal models of NIDDM. Dehydrotrametenolic acid is a promising candidate for a new type of insulin-sensitizing drug. This finding is very important for the development of insulin sensitizers that are not of the thiazolidine type.     

Effect of phenylephrine injected into the nucleus tractus solitarius of Sprague-Dawley rats and spontaneously hypertensive rats

In alpha-chloralose-anesthetized Sprague-Dawley (SD) rats with unilateral nucleus tractus solitarius (NTS) lesions, injection of the alpha(1)-adrenergic receptor agonist phenylephrine into the contralateral NTS dose-dependently increased arterial pressure (AP). Bunazosin (0.1 nmol) or prazosin (0.36 nmol), an alpha(1)-adrenergic receptor antagonist, also increased AP. When injected into the NTS, pre-treatment with phenylephrine (10 nmol) or both antagonists abolished the cardiovascular effects of glutamate and acetylcholine. In contrast, pre-treatment with prazosin or methylatropine did not alter the effect of phenylephrine. Phenylephrine (30 nmol) injected into the NTS abolished aortic depressor nerve (ADN) evoked-responses. The pressor effect of phenylephrine in the NTS was exaggerated in spontaneously hypertensive rats (SHR). These results suggest that when injected into the NTS, the effect of phenylephrine may be due to a baroreflex blockade resulting from direct modulatory actions or non-specific neuronal alterations rather than stimulating the alpha(1)-adrenergic receptor. Additionally, this effect is enhanced in SHR.