Microwave-assisted hydrolysis of biomass over activated carbon supported polyoxometalates

Activated carbon supported polyoxometalates (AC-POMs) were used for acceleration of hydrolysis of biomass under microwave irradiation.

Effects of lidocaine on blood flow and endoneurial fluid pressure in a rat model of herniated nucleus pulposus

STUDY DESIGN

An experimental study was conducted to evaluate the effects of lidocaine on nucleus pulposus-induced pathophysiologic changes.

OBJECTIVES

To investigate the effects of lidocaine on blood flow in the hind paws and endoneurial fluid pressure in the dorsal root ganglia in a rat model of herniated nucleus pulposus, and to clarify the therapeutic mechanisms of nerve root infiltration.

SUMMARY OF BACKGROUND DATA

It has been shown experimentally that application of nucleus pulposus to the nerve roots increases endoneurial fluid pressure and decreases blood flow in the dorsal root ganglia and the corresponding hind paw. These changes are thought to be an important pathogenic mechanism associated with sciatica caused by disc herniation. Nerve root infiltration is one of the nonoperative effective therapies for radiculopathy caused by disc herniation. However, the therapeutic mechanisms still are unknown.

METHODS

For this study, 21 Sprague-Dawley rats were used. Autologous nucleus pulposus was applied to the nerve root with a piece of Spongel containing lidocaine (lido group) or physiologic saline solution (control group). In Series 1 of this study (Blood Flow in the Hind Paw), blood flow in the corresponding hind paws was monitored continuously using a laser Doppler flowmeter before application of the test solutions, and every 5 minutes thereafter for an additional 3 hours in both the control (n = 5) and lido (n = 5) groups. In Series 2 of this study (Endoneurial Fluid Pressure in the Dorsal Root Ganglion), endoneurial fluid pressure was recorded with a servo-null micropipette system using glass micropipettes before and 3 hours after application of the test solutions in both the control (n = 6) and lido (n = 5) groups. After measurements, dorsal root ganglia were assessed for histology.

RESULTS

In Series 1, blood flow in the corresponding hind paw in the control group showed significant reduction as compared with that of the Lido group, starting about 90 minutes after application (P < 0.01-0.05). Hind paw blood flow in the lido group did not show any reduction during measurements. In Series 2, the value of endoneurial fluid pressure in the lido group 3 hours after application was significantly lower than in the control group (P < 0.01). Interstitial (endoneurial) edema in the dorsal root ganglion in the lido group appeared to be qualitatively less than in the control group.

CONCLUSIONS

The data indicate that lidocaine reduces the pathophysiologic changes in the dorsal root ganglion and hind paws induced by nucleus pulposus. These effects of lidocaine may relate to the mechanisms underlying the therapeutic effects of nerve root infiltration.

Prevention of compartment syndrome in dorsal root ganglia caused by exposure to nucleus pulposus

STUDY DESIGN

An experimental study to clarify the effects of pentoxifylline, as an anti-tumor necrosis factor-alpha therapy on endoneurial fluid pressure in the dorsal root ganglion using an animal model of herniated nucleus pulposus.

OBJECTIVES

To investigate the effects of anti-tumor necrosis factor-alpha therapy to nucleus pulposus-induced nerve root/dorsal root ganglion changes.

SUMMARY OF BACKGROUND DATA

It has been reported experimentally that application of nucleus pulposus into epidural space induces morphologic and functional changes in the nerve roots and induces compartment syndrome in the dorsal root ganglia. Tumor necrosis factor-alpha has been considered a key pathogenic factor in the initiation and maintenance of neuropathic pain states.

METHODS

A total of 11 adult, female Sprague-Dawley rats had their left L5 nerve roots and associated dorsal root ganglions exposed. Autologous nucleus pulposus was applied to the L5 nerve root just proximal to the dorsal root ganglion. A piece of Spongel (Yamanouchi Pharmaceutical Co., Tokyo) containing 20 microL of 1000 microg/mL pentoxifylline was applied with the nucleus pulposus (NP+PTX group). In control animals nucleus pulposus was applied with a piece of Spongel containing 20 microL of physiologic saline solution in a similar fashion (NP+PS group). Endoneurial fluid pressure was recorded with a servo-null micropipette system using glass micropipettes with tip diameters of 4 microm. Endoneurial fluid pressure in the dorsal root ganglion was measured before and 3 hours after application of test substances. After measurement of endoneurial fluid pressure, the nerve root and dorsal root ganglion were processed for histology and evaluated by light microscope.

RESULTS

Values of endoneurial fluid pressure before application of test substances were as follows: 2.4 +/- 1.2 cm H2O in the NP+PS (control) group and 1.8 +/- 0.4 cm H2O in the NP+PTX group. There was no statistically significant difference between these two pretreatment measurements. However, values of endoneurial fluid pressure after application were as follows: 8.6 +/- 1.8 cm H2O in the NP+PS group and 2.9 +/- 0.8 cm H2O in the NP+PTX group. Values of endoneurial fluid pressure in the NP+PTX group were significantly lower compared with the NP+PS group. Histologic examination consistently showed only a slight degree of edema evident in the NP+PTX group compared with the NP+PS group.

CONCLUSION

Pentoxifylline, an anti-tumor necrosis factor-alpha drug, prevented the dorsal root ganglion compartment syndrome caused by topical application of nucleus pulposus. Anti-inflammatory cytokine therapy may become an effective treatment of sciatica due to disc herniation.

Molecular nature of colon tumors in hereditary nonpolyposis colon cancer, familial polyposis, and sporadic colon cancer

BACKGROUND & AIMS

Microsatellite instability (replication error [RER]) is a characteristic of tumors in hereditary nonpolyposis colon cancer (HNPCC), but the mechanism of HNPCC carcinogenesis is not yet understood. To clarify the nature of HNPCC tumors, RER and genetic changes were compared between HNPCC and non-HNPCC tumors.

METHODS

RER and genetic changes were analyzed in 21 HNPCC, 389 familial adenomatous polyposis, and 206 sporadic tumors using polymerase chain reaction, single-strand conformation polymorphism, sequencing, and Southern hybridization. RESULTS. in HNPCC, 95% tumors at all stages showed RER positivity (altered loci, 4.3 of 5). In familial adenomatous polyposis and sporadic tumors, RER positivity (1.7 of 5) was 3% in adenoma and intramucosal carcinoma, 13%-24% in invasive carcinoma, and 35% in carcinoma metastasized to liver. Fifty percent of RER-positive HNPCC tumors had both germline and somatic mutations of hMSH2 or hMLH1 gene, whereas 6% of RER-positive non-HNPCC had somatic mutation. APC, p53, and K-ras-2 mutations and loss of heterozygosity of tumor-suppressor genes were significantly less frequent (P = 0.03 to 0.0006) but transforming growth factor beta type II receptor mutation was significantly more frequent (P = 0.000001) in HNPCC than in non-HNPCC.

CONCLUSIONS

RER positivity occurs from an early stage of carcinogenesis in HNPCC but in later stages in non-HNPCC. Most HNPCC tumors may develop through different genetic changes from those in the adenoma-carcinoma sequence, although a certain percentage develops through APC mutation.