Stimulation of reseptors for α₁-adrenergic agonist, endothelin (ET) and angiotensin II (AT) activates the cardiac sarcolemmal Na⁺/H⁺exchanger (NHE), perhaps via protein kinase C(PKC)-mediated pathway(s). We tested for the ability of these extracellular stimuli to exacerbate reperfusion arrhythmias and for the possible role of NHE activation and PKC in such phenomena. Isolated rat hearts (n=12/group) were subjected to dual coronary perfusion. After 15 min of aerobic perfusion, flow to the left coronary bed was reduced to 5% of basal values for 12 min, and the same bed was then reperfused for 5 min. An α₁-adrenergic agonist phenylephrine (PE) at 1 or l0, μmol/L, ET at 0.5 or 5nmol/L or AT at 1 or 10μmol/ L was infused selectively into the left coronary bed during 12min of regional low flow ischemia. The incidence of reperfusion-induced ventricular fibrillation (VF) was increased from 17% in control to 33% and 75%* with 1 and 10μmol/L PE(*p<0.05 vs control), from 8% in control to 8% and 42% with 0.5 and 5 nmol/L of ET. However, AT had no effect. The selective NHE inhibitor NOE642 at lμmol/L, infused concomitantly with l0pmol/L PE, reversed the proarrhythmic effects of PE; VF incidence was reduced from 67% to 8%*. However, glibenclamide (a blocker for the ATP-sensitive K⁺channel) at l1cmol/L did not affect the proarrhythmic effects of PE. Infusion of a specific PKC inhibitor GF109203X(GF) at 30 or 300nmol/L, starting from 5 min before ischemia and maintained throughout ischemia concomitantly with l0, umol/L of PE, was partially effective in reducing VF incidence ; which reduced from 75% in control to 42% with 300nmol/L of GF. These results suggest that, in rat hearts subjected to regional low-flow ischemia and reperfusion, stimulation of a ₁-adrenergic receptor can exacerbate reperfusion-induced VF, whose mechanism(s) may involve NHE activation. Moreover, PKC activation does not appear to be the sole signaling mechanism for this phenomenon. (J Nippon Med Sch 1998; 65:276-283)

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This study was undertaken to biochemically and immunohistochemically clarify the expression of basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I), fibroblast growth factor receptor (bFGFR), insulin-like growth factor-I receptor (IGF-IR) and vascular smooth muscle cell (VSMC) growth by using Streptozotocin (STZ) treated rat serum.
At 12, 16, 24 weeks after STZ administration, blood sera were collected from STZ treated rats. STZ treated rat sera promoted much more vascular smooth muscle cell proliferation than control sera. IGF-I was increased in the sera of STZ treated rats. Also according to western blot analysis, the protein synthesis of bFGFR and IGF-IR in the VSMCs was increased in STZ treated rat sera. Immunohistochemically, bFGF, IGF-I and their receptors were much more localized in VSMCs in STZ treated rat sera than in control sera. These results suggest that the growth factors and their receptors produced in VSMCs in STZ treated rat serum may contribute to the proliferation of VSMCs in autocrine and paracrine patterns. (J Nippon Med Sch 1998 ; 65:284-290)

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To investigate the role of cervical proprioceptive inputs in the process of vestibular compensation, we performed static posturography in patients with acute and compensated unilateral vestibular dysfunction, by applying vibratory stimulation to the dorsal neck muscles. Neck vibration induced disequilibrium in both groups of patients, but was more pronounced in the compensated patients. These results indicate that manipulation of the neck afferents causes discompensation in subjects whose vestibular dysfunction has already been compensated by multisensory inputs including neck afferents. (J Nippon Med Sch 1998; 65:291-297)

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To obtain a fundamental knowledge of the morphological relationship between nerve root symptoms and circulatory disorders, the distribusion pattern of the veins in the lumbar spinal ganglia from the first to fifth vertebrae was investigated in 5 adult human cadavers (mean age 69.6 years) and 5 human fetuses (mean age 6.6 months).
The following results were obtained:
1) In the adults the veins perforating from the outer surface of the fifth lumbar spinal ganglion were smaller in number than those perforating from the first to fourth ganglia. In contrast, in the fetuses the number of such veins was increased in the lower lumbar spinal ganglia. In each of the ganglia, the number of veins emerging through the dorsal side was much higher than the number perforating from the outer surface of the ventral sides. The veins perforating through the outer surface of the ganglion formed weak venous networks (periganglionic venous plexus) surrounding the dorsal ramus of the spinal nerve.
2) The veins communicating with the tributaries from the periganglionic venous plexus were classified into three types. Type 1 veins flowed into the intervertebral veins (the frequency ranged from 9.2 to 18.2 in the adults and from 22.4 to 37.0 in the fetuses). Type 2 veins coursed in the spinal cord along the dorsal root fibers and penetrated the dura mater on the way (the frequency ranged from 0.4 to 4.8 in the adults and from 1.2 to 2.2 in the fetuses). Type 3 veins opened directly into the internal vertebral plexus (the frequency ranged from 0.4 to 1.8 in the adults and from 0 to 0.4 in the fetuses). Type 1 veins were the most frequent among the three types of veins in both adults and fetuses. Few type 3 veins were observed in either group.
3) In the first and second lumbar vertebrae in the adults, three-quarters of each spinal ganglion was situated in the vertebral canal. In the lower lumbar region (L3-L5), three quarters of each spinal ganglion lay on the outside of the vertebral canal. In the fetuses, approximately one half to three-quarters of each lumbar spinal ganglion was located in the vertebral canal. (J Nippon Med Sch 1998 ; 65:298-306)

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A postal questionnaire for the prevalence of low back pain was studied with relevance to stiffness of that shoulder and a history of low back disorders in construction employees. The percentage of clerical employees with low back pain was 31.3% and of field workers was 30.3%.
Odds ratios representing a relative risk factor for low back pain relating to each age group showed 2.35 in the clerical and 2.10 in the field workers at the age of 30-34 years, and 3.34 and 2.58 at the age of 35-39 years, respectively.
In the persons with positive previous low back pain, the prevalence rate of low back pain was 52.6% in the clerical, and 50.2% in the field workers.
Odds ratios for low back pain relating to previous low back pain significantly exceeded unity for the clerical employees (OR=9.53) and the field workers (OR=10.28), compared to those without a history of previous low back pain.
The incidence of stiffness of the shoulder was 48.2% in the clerical and 45.2% in the field workers, and the prevalence rate of low back pain among those with stiffness of the shoulder was 68.5% in the clerical and 65.8% in the field workers. Odds ratio were 3.03 in both groups.
Among each age group, the prevalence rate of stiffness of the shoulder with low back pain increased gradually to a maximum in the 45-49 age group of 19%, and then dropped.
In those with a history of low back pain and/or stiffness of the shoulder, the prevalence of low back pain showed significantly greater value than other risk factors. (J Nippon Med Sch 1998 ; 65: 307-311)

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A 5-week-old male infant who was referred to our hospital because of tachypnea and poor feeding. An electrocardiogram showed a deep Q wave in lead _aV_L, negative T waves in leads I, II, III, _aV_F and V₆ and a positive T wave in V₁. Echocardiography revealed severely impaired left ventricular function. Aortography confirmed with a diagnosis of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA). Takeuchi's procedure was performed and the patient maintained postoperatively on assisted circulation for 7hours even though sternal closure delayed until 7 days post operatively. His left ventricular function showed and marked improvement gradually. (J Nippon Med Sch 1998; 65: 312-315)

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Surgery for posterior skull base tumors may be associated with high morbidity and mortality because of the complex anatomy, irregular bony topography, and vital neurovascular structures in this region. We experienced three benign posterior skull base tumors. These were petroclival and foramen magnum meningiomas and a jugular formen neurinoma. Three dimensional computed tomography (3D-CT) in addition to the conventional CT, magnetic resonance imaging (MRI), and cerebral angiography were performed preoperatively. Preoperative embolizations for the tumors were also done, and intraoperative neurophysiological monitorings were performed.
The tumors could be subtotally removed with no damage to the brainstem, cranial nerves, and vessels. No newly developed postoperative neurological symptoms were observed. As to the remaining tumors, gamma knife (y-knife) therapy was planned.
3D-CT was very useful in the preoperative evaluation of the surgical approach, and the intraoperative neurophysiological monitoring was considered to be necessary to prevent permanent damage. γ-knife after direct approach was recommended for the benign posterior skull base tumors. (J Nippon Med Sch 1998; 65: 316-319)

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