Permanent inflation of detachable balloons with a low-viscosity, hydrophilic polymerizing system

A polymer system was developed for use in permanent inflation of detachable balloons, to avoid long-term reliance on the integrity of balloon shells or valve mechanisms. This system is based on 2-hydroxy-ethyl methacrylate (HEMA) as the monomer, in combination with a cross-linking agent and a water-soluble curing system. The low-viscosity, hydrophilic mixture can be exchanged through a small-bore catheter into a detachable balloon and polymerizes in 40-60 minutes at body temperature. Partially polymerized HEMA can cause vascular occlusion; hence, careful timing of balloon detachment is required. The evolution of the radiographic appearance of HEMA-filled balloons is predictable. The balloons remain radiopaque on plain radiographs as long as the balloon shell and valve mechanisms are competent. After rupture of the shell or failure of the valve mechanism, the balloons become invisible on plain radiographs but remain hyperattenuating on computed tomography scans.     

Application of image-guided surface coil P-31 MR spectroscopy to human liver, heart, and kidney

Localized phosphorus-31 magnetic resonance (MR) spectroscopy in humans has previously been accomplished with surface coils by means of depth-resolved surface coil spectroscopy or rotating frame experiments, in which the extent of tissue sampled critically depends on surface coil placement. The authors' goal was to modify the surface coil image-selected in vivo spectroscopy (ISIS) experiment to accomplish three-dimensional volume selection through application of selective pulses in the presence of B0 gradients. Advantages of ISIS include the ability to use proton images to define the volume of interest (VOI) and reduced dependence on exact positioning of the surface coil. However, rapid replication of the surface coil ISIS experiment can cause spectral contamination from signals originating outside the VOI. A modified version of the ISIS experiment was developed to alleviate contamination under conditions of rapid replication. Applications of localized P-31 MR spectroscopy for observation of high-energy phosphorus metabolites are presented in human liver, heart, and transplanted and normal kidney.     

氯化四乙基铵及维拉帕米对家兔缺血心肌不应期的影响

实验比较了K⁺通道阻断剂氯化四乙基铵(TEA)及Ca²⁺通道阻断剂维拉帕米(verapamil,Ver)对家兔缺血性心室肌不应期(ERP)的影响。结果表明,阻断冠脉10min及30min后,缺血中心区(CIZ)和缺血边缘区(BIZ)心肌ERP比缺血前均明显缩短,而TEA和Ver均能延长急性缺血性心肌的ERP,可能对心肌缺血引起的心律失常有预防作用。     

Chronic graft-versus-host disease in 52 patients: adverse natural course and successful treatment with combination immunosuppression

Fifty-two of 175 (30%) survivors of allogeneic marrow transplantation developed chronic graft-versus-hose diseases (GVHD). Five with limited chronic GVHD had an indolent clinical course with involvement of only the skin and liver. Forty-seven with extensive chronic GVHD had an unfavorable multiorgan disorder that resembled several autoimmune diseases. Thirteen patients with extensive disease (group I) were not treated and only 2 survive with Karnofsky scores >- 70%. Mortality resulted from infections and morbidity from sica syndrome, pulmonary and hepatic insufficiency, scleroderma-like skin disease, and contractures. Another 13 (group II) received a median of 8 mo prednisone and/or a brief course of antithymocyte globulin, and 3 survive without disability. The other 21 (group III) were treated with a combination of prednisone (1.0 mg/kg/q.o.d.) and either cyclophosphamide, procarbazine, or azathioprine (all 1.5 mg/kg/day) for a median of 13 mo. Combination therapy was well tolerated with only modest myelotoxicity. Fifteen in group III had a good and 4 a fair response to treatment while 2 with no response died. Azathioprine and prednisone was the most effective regimen. All therapy has been discontinued in 12 group III patients: GVHD returned in 5 (including 2 who died in spite of retreatment) while 7 remain free of GVHD for a median of 11 (range 6-30) mo observation. Only I group III survivor is disabled and 16 of the original 21 are alive 2-4 yr after transplant with Karnofsky scores of 70%-100%. Thus, combination immmunosuppression appears to favorably affect and, in some cases, premanently arrest the adverse natural course of extensive chronic GVHD.     

Technique for axillary radiotherapy using computer‐assisted planning for high‐risk skin cancer†

High‐risk skin cancer arising on the upper limb or trunk can cause axillary nodal metastases. Previous studies have shown that axillary radiotherapy improves regional control. There is little published work on technique. Technique standardization is important in quality assurance and comparison of results especially for trials. Our technique, planned with CT assistance, is presented. To assess efficacy, an audit of patients treated in our institution over a 15‐month period was conducted. Of 24 patients treated, 13 were treated with radical intent, 11 with this technique. With a follow up of over 2 years, the technique had more than a 90% (10/11) regional control in this radical group. Both of the radical patients who were not treated according to the technique had regional failure. One case of late toxicity was found, of asymptomatic lymphoedema in a radically treated patient. This technique for axillary radiotherapy for regional control of skin cancer is acceptable in terms of disease control and toxicity as validated by audit at 2 years.     

Total and partial hypothalamic deafferentations for topographical identification of catecholaminergic innervations of certain preoptic and hypothalamic nuclei

Acquisition of nicititating membrane (NM) conditioned responses (CRs) to tone onset was studied in male albino rabbits with their heads immobilized and bodies loosely restrained. The conditioned stimulus (CS) was a 1000 Hz tone presented over a white noise background. The unconditioned stimulus (US) was an air puff directed at the exposed cornea. NM closure was detected with an integrated circuit infrared light reflection transducer. The latency of the unconditioned response (UR) was 17.5 msec from puff onset at the cornea. URs were bilateral. All 22 experimental rabbits showed CR acquisition in the eye to which puff was delivered on training Day I. Group response rates approached 80% in the last 40 trials of Day I. During Days II and III, the rate was between 90 and 100%. Mean CR response latency decreased significantly from 177 msec on Day I to 135 msec on Day II. None of the 9 pseudoconditioning control animals showed CR acquisition. A learning curve was constructed with the trial of the tenth CR (rather than trial 0) as the anchor point. The probability of CR occurrence showed an abrupt 50% increase between trials—12 and —11 (before the anchor point) when examined in this fashion. NM performance of the non-puff eye (eye not receiving the air puff US) was determined in 13 rabbits. CRs were determined to be largely unilateral. When non-puff CRs were present, they were of significantly longer latency and of smaller size than those occuring simultaneously in the puff eye. The advantages of rabbit NM conditioning as a system in which to examine the neurophysiological and anatomical substrates of learning were discussed.