Effect of alkyl groups on the rate constants of propagation and termination in the radical polymerization of dialkyl itaconates

Polymerization of dialkyl itaconates with dimethyl azoisobutyrate ( 5 ) was studied in benzene at 50°C by means of electron spin resonance (ESR). The monomers used are dimethyl ( 1 ), diethyl ( 2 ), dibutyl ( 3 ) and di-2-ethylhexyl ( 4 ) itaconates. All the polymerization systems involve ESR-observable propagating polymer radicals under the actual polymerization conditions. The polymerization rate (R_p) and degree of polymerization of the resulting polymer increase in going from shorter to longer alkyl groups. The ESR-determined rate constants of propagation (k_p) and termination (k_t) decrease as the alkyl chain becomes longer. k_p of 1 is 3,3 times higher than that of 4 , while k_t of 1 is 590 times higher than that of 4 . Thus, the steric effect due to the alkyl group suppresses much more termination than propagation, leading to the fact that R_p increases as the alkyl group becomes larger.     

Response of the visual system evoked by an alternating current

Alternating current stimulation of the eye generates an occipital electrically evoked response (a.c.-e.e.r.) of which the frequency characteristic shows a monophasic pattern for which the optimum stimulus frequency for evoking a maximum response is 18 Hz. A.C.-E.E.R. is a very useful tool for making a diagnosis of pigmentary retinal dystrophy and is different from the e.r.g. in that it is not affected by diseases of the optical system such as strong refractive anomalies or vitreous opacities.     

Preemptive analgesia by zaltoprofen that inhibits bradykinin action and cyclooxygenase in a post-operative pain model

The post-operative pain state results from a barrage of primary afferent inputs exposed to products of tissue damage such as bradykinin and prostaglandins and the central sensitization by the continuing inputs. This provides the rationale for preemptive analgesia, whereby the blockade of primary afferent inputs prior to injury may result in a reduction of post-operative pain. 2-(10,11-dihydro-10-oxo-dibenzo[b,f]thiepin-2-yl) propionic acid (zaltoprofen) is a unique compound that inhibits cyclooxygenase (COX) and exhibits anti-bradykinin activity. The present study evaluated the preemptive analgesic effect of zaltoprofen in a post-operative pain model produced by plantar incision. When orally, but no intrathecally, administered 30 min prior to incision, zaltoprofen significantly increased the withdrawal threshold 2 h and 1-3 days after incision at 10 mg/kg. While the bradykinin B1 antagonist des-Arg10-HOE-140, the selective COX-1 inhibitor SC-560, and the selective COX-2 inhibitor celecoxib did not affect post-operative pain, the B2 antagonist HOE-140 dose-dependently relieved the post-operative pain at 2-200 microg/kg with a time course similar to that of zaltoprofen. The B2 receptor mRNA was expressed in the hindpaw and the expression did not change before and 24 h after surgery. These results suggest that zaltoprofen produces the preemptive analgesic effect peripherally by blocking the B2 pathway.     

Anterior Transhepatic Approach for Isolated Resection of the Caudate Lobe of the Liver

RID=" ID=" <E5>Correspondence to:</E5> J. Yamamoto, M.D.     

A Comparison of Visual Field and Optic Disc Appearance Depending on the Peak Intraocular Pressure in Patients with Normal-tension Glaucoma

Purpose To review the outcome of surgery for strabismus due to ethmoid sinus surgery.Cases and Methods The series comprised 13 cases, 1 of inferior rectus paresis, 1 of superior oblique paresis, 6 of medial rectus paresis, and 5 of medial rectus muscle palsy due to third nerve palsy. In the cases of paresis of the rectus muscle, resection of the rectus muscles was mainly performed. In the cases of palsy of the rectus muscle, transposition of the extraocular muscle with simultaneous recession of the lateral rectus muscle was performed. The major aim of surgery was to bring both eyes into alignment and to eliminate diplopia in the primary position.Results The mean preoperative horizontal deviation of 18.1 degrees of exotropia in the paresis cases was reduced to 1.4 degrees of exotropia after surgery. The mean preoperative vertical deviation of 3.8 degrees of hypertropia was reduced to 1.4 degrees of hypertropia postoperatively. The mean preoperative horizontal deviation of 35.6 degrees of exotropia in the palsy cases was reduced to 9.4 degrees of exotropia after surgery. The mean preoperative vertical deviation of 2.0 degrees of hypertropia was increased to 2.6 degrees of hypertropia postoperatively. Postoperatively, diplopia was absent in 11 cases with a slightly compensatory head posture.Conclusions Surgery for strabismus due to sinus surgery induces improvements in eye position and diplopia. Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc 107:425–432, 2003)     

Intestinal Behçet's disease associated with non-Hodgkin's lymphoma

A 45-year-old man with intestinal Behçet's disease noticed an enlarged right cervical lymph node, and was diagnosed with diffuse large cell type, non-Hodgkin's lymphoma. The intrapelvic lymph tract was markedly deformed because of recurrent ileocecal ulceration, and conventional lymphoscintigraphy with a common tracer did not abolish the suspicion that lymphoma cells may have invaded the lymph nodes. Dynamic lymphoscintigraphy with a new tracer,^99mtechnetium-diethylene triamine pentaacetic acid-human serum albumin, because of its high detection sensitivity, was very useful for excluding this suspicion, and for determining the clinical stage of lymphoma. Combination induction chemotherapy led to complete remission without any adverse effects, but subsequent supportive therapy with same protocol could not be completed because of progression of the intestinal lesions. Special management for the intestinal lesions, such as bowel rest, may be essential with chemotherapy for patients with intestinal Behçet's disease.