Excitatory mechanism of deflationary slowly adapting pulmonary stretch receptors in the rat lung.

The excitatory responses of deflationary slowly adapting pulmonary stretch receptor (SAR) activity to lung deflation ranging from approximately -15 to -25 cm of H(2)O for approximately 5 s were examined before and after administration of flecainide, a Na(+) channel blocker, and K(+) channel blockers, such as 4-aminopyridine (4-AP) and tetraethylammonium (TEA). The experiments were performed in anesthetized, artificially ventilated rats after unilateral vagotomy. The deflationary SARs increased their activity during lung deflation and its effect became more pronounced by increasing the degree of negative pressure. During lung deflation the average values for the deflationary SAR adaptation index (AI) were below 40%. Intravenous administration of veratridine (50 microg/kg), an Na(+) channel opener, stimulated deflationary SAR activity: one maintained excitatory activity mainly during deflation and the other receptors showed a tonic discharge during both deflation and inflation. Despite the difference in deflationary SAR firing patterns after veratridine administration, flecainide treatment (6.0 mg/kg) blocked veratridine-induced deflationary SAR stimulation and also caused strong inhibition of the excitatory responses of deflationary SARs to lung deflation. Under these conditions, the average values for deflationary SAR AI were over 90%. The responses of deflationary SARs and deflationary SAR AI to lung deflation were not significantly altered by pretreatment with either 4-AP (0.7 and 2.0 mg/kg) or TEA (2.0 and 6.0 mg/kg). These results suggest that the excitatory effect of lung deflation on deflationary SAR activity is mediated by the activation of flecainide-sensitive Na(+) channels on the nerve terminals of deflationary SARs.     

Percutaneous radiofrequency neurotomy of lumbar medial branch (facet rhizotomy)--a report of 6 cases

We performed radiofrequency neurotomy of lumbar medial branch as a treatment of facet syndrome. Our six cases had no indication for surgical therapy, such as neuralgia, spinal canal stenosis without neurological deficit except for pain and deformed spines. Facet joint injection with regional anesthetics and steroids could not prevent their recurrent back pain. By facet rhizotomy, they could obtain relief of back pain for several months to a year. We conclude that facet rhizotomy is a more effective method for facet syndrome when a proper indication is present.     

β2-glycoprotein I, anti-β2-glycoprotein I, and fibrinolysis

β₂-glycoprotein-I (β₂GPI) is a phospholipid-binding plasma protein that consists of five homologous domains. Domain V is distinguished from others by bearing a positively charged lysine cluster and hydrophobic extra C-terminal loop. β₂GPI has been known as a natural anticoagulant regulator. β₂GPI exerts anticoagulant activity by inhibition of phospholipid-dependent coagulation reactions such as prothrombinase, tenase, and factor XII activation. It also binds factor XI and inhibits its activation. On the other hand, β₂GPI inhibits anticoagulant activity of activated protein C. According to the data from knockout mice, β₂GPI may contribute to thrombin generation in vivo. Phospholipid-bound β₂GPI is one of the major target antigens for antiphospholipid antibodies present in patients with antiphospholipid syndrome (APS). Binding of pathogenic anti-β₂GPI antibodies increases the affinity of β₂GPI to the cell surface and disrupts the coagulation/fibrinolysis balance on the cell surface. These pathogenic antibodies activate endothelial cells via signal transduction events in the presence of β₂GPI. Impaired fibrinolysis has been reported in patients with APS. Using a newly developed chromogenic assay, we demonstrated lower activity of intrinsic fibrinolysis in euglobulin fractions from APS patients. Addition of monoclonal anti-β₂GPI antibodies with β₂GPI also decreased fibrinolytic activity in this assay system. β₂GPI is proteolytically cleaved by plasmin in domain V (nicked β₂GPI) and becomes unable to bind to phospholipids, reducing antigenicity against antiphospholipid antibodies. This cleavage occurs in patients with increased fibrinolysis turnover. Nicked β₂GPI binds to plasminogen and suppresses plasmin generation in the presence of fibrin, plasminogen, and tissue plasminogen activator (tPA). Thus, nicked β₂GPI plays a role in the extrinsic fibrinolysis via a negative feedback pathway loop.     

Ultrasonic duplex system to facilitate assessment of portal blood flow velocity

The usefulness of an ultrasonic duplex system to assess portal blood flow was investigated. In a model involving a steady flow through a vinyl tube in agar, there was a significant linear correlation between the maximum blood flow velocity measured by this system (V-max) and the mean blood flow velocity calculated from the actually measured blood flow volume (V-mean), that is, V-mean = 0.53 X V-max was obtained (r = 0.994; n = 47). This equation was used to calculate the mean portal blood flow velocity by this system (V-dopp) in 10 patients with liver disease, and the findings were compared with data simultaneously obtained by cineangiographic mapping of Lipiodol droplets released into the portal vein through a catheter placed in situ at the time of surgery (V-cine). A linear correlation between V-dopp and V-cine was statistically significant (r = 0.970; n = 13), and the regression line was V-cine = 1.29 X V-dopp -2.11. The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.     

An elderly case of systemic lupus erythematosus associated with herpes zoster, anemia, and hemiparesis]

An elderly case of systemic lupus erythematosus (SLE) with suspected hemolytic anemia was experienced. A 70 year-old female was admitted to our hospital on December 31 with complaints of herpetic eruption. She complained of arthralgia since 3 month prior to her admission. The positive findings on examination were skin eruption in the left chest, a systolic heart murmur and a palpable elastic hard liver. Laboratory data showed raised erythrocyte sedimentation rate of 149 mm per hour, decreased Hb (10.1 g/dl), decreased hematocrit (30.0%), increased reticulocytes (33%1000), decreased thrombocytes (73,000/mm3), increased gamma-globulin (33%) and positive rheumatoid factor. During admission, she developed anemia. A stool test for occult blood was negative. The haptoglobin was 38.8 mg/dl and bone marrow aspiration showed increased erythropoiesis, suggesting features of immune hemolytic anemia, except she was negative on Coomb'test. Eye fundi were similar to case of typical bleeding observed in SLE. Concerning immunological findings, the antinuclear factor was x 1280 and the anti-dsDNA antibody was x 80, on which a diagnosis of SLE was based. She experienced numbness of the left arm and developed left hemiparesis 2 days later. Therapy with 15 mg/day prednisone obtained a good response and anemia, abnormal immunological findings and hemiparesis disappeared.     

Calorie restriction increases serum parathyroid hormone and decreases serum calcitonin levels in patients with maturity onset diabetes mellitus

Calorie restriction is important in managing patients with maturity onset diabetes mellitus (NIDDM). The effect of such restriction on calcium metabolism is not known. The objective of this study was to determine whether patients on calorie restricted diets would show any modification of parathyroid hormone (PTH) and calcitonin (CTN). The serum levels of PTH and CTN were measured by radioimmunoassays in 269 patients with NIDDM. The patients were divided into two groups depending on the intake of calorie, and PTH and CTN were monitored for 2 years. Plasma levels of vitamin D were measured by competitive protein binding assays before and after each program. The level of PTH (520.8±266.0 pg/ml) (mean±S.D.) was significantly (P<0.01) higher in 109 diabetic patients whose calorie intake was restricted for 2 years (diet (D) group) as compared with that (256.6±103.8 pg/ml) of 160 diabetic patients whose calorie intake was not restricted (non-diet (ND) group). The daily oral calcium intake of the two groups did not differ significantly. We found no significant difference in the serum PTH level in the ND groupVS. normal control subjects (248.8±98.4, N=78). The serum calcium concentration and the amount of calcium excreted in urine were slightly but significantly (P<0.01) lower in the D than in the ND group. The rate of tubular reabsorption of phosphate (% TRP) was significantly lower in the D group than that in the ND group (P<0.01). The serum CTN level was significantly (P<0.01) lower in the D group (33.9±11.3 pg/ml) than in the ND group (64.9±21.2 pg/ml) 2 years after each treatment. The plasma 1,25-(OH)₂-vitamin D level was significantly (P<0.01) lower in the D group (22.2±6.6 pg/ml) than in the ND group (50.6±4.2 pg/ml). When the restriction of calorie intake in the D group was canceled, their PTH levels decreased, which was accompanied by increase in the 1,25-(OH)₂-vitamin D levels, whereas their CTN levels were unchanged. These observations suggested that a restricted calorie intake is a risk factor for secondary hyperparathyroidism as well as for a low serum level of CTN in patients with NIDDM.     

Langerhans Cell Histiocytosis Presenting as a Varicelliform Eruption over the Entire Skin

A boy with skin eruptions resembling varicella and specific for Langerhans cell histiocytosis (LCH) is reported. At his initial visit when he was four months old, vesiculopustular lesions were present over the entire body; these had first appeared on the third day post partus. Histopathological, immunohistochemical, and electron microscopical examination confirmed the Langerhans cell phenotype and Birbeck granules in the responsible cells. He also had hydronephrosis, recurrent fever, and cutaneous bacterial infections. His parents refused further medical treatment and he died of diarrhea with cachexia about two years later. LCH may present diagnostic difficulties by manifesting as a skin eruption which resembles varicella.