Both D-cis- and L-cis-diltiazem attenuate hydrogen peroxide-induced derangements in rat hearts

The effects of D-cis- and L-cis-diltiazem on the hydrogen peroxide (H2O2)-induced derangements of mechanical function and energy metabolism, and accumulation of intracellular Na+ were studied in isolated rat hearts. The intracellular concentration of Na+ ([Na+]i) in the myocardium was measured using a nuclear magnetic resonance technique. H2O2 (600 microM) increased the left ventricular end-diastolic pressure, decreased the tissue level of ATP, and increased the release of lactate dehydrogenase from the myocardium. These alterations induced by H2O2 were significantly attenuated by D-cis-diltiazem (15 microM) or L-cis-diltiazem (15 microM). H2O2 (1 mM) produced a marked increase in the myocardial [Na+]i, which was effectively inhibited by tetrodotoxin (3 microM), D-cis-diltiazem (15 microM) or L-cis-diltiazem (15 microM). These results suggest that both D-cis- and L-cis-diltiazem protect the myocardium against the H2O2-induced derangements in the isolated, perfused rat heart. The protective action of D-cis- and L-cis-diltiazem may be due to their ability to inhibit the H2O2-induced increase in [Na+]i, at least in part.

Electromyographic evaluation after endoscopic carpal tunnel release in idiopathic carpal tunnel syndrome

The purpose of this study was to electromyographically evaluate results in patients with carpal tunnel syndrome (CTS) who underwent endoscopic carpal tunnel release (ECTR). The subjects were 26 patients with idiopathic CTS (37 hands) who were followed for at least 6 months after ECTR. To compare results informatively, hands were classified into four groups: those with normal distal motor latency (DML) and sensory conduction velocity (SCV) were classified as group A, those with normal DML and abnormal SCV as group B, those with an abnormal DML and normal SCV as group C, and those with abnormal DML and SCV as group D. All but one of the hands were classified as group D on the basis of preoperative electromyographic evaluation, while one was classified as group C. The mean preoperative obtainable DML and SCV values were 7.2 m and 27.3 m/s, respectively. Postoperatively, 12 hands were in group A, 8 hands in group B, 2 hands in group C, and 15 hands in group D. The mean DML and SCV values at final follow-up were 4.3 ms and 40.8 m/s, respectively. Of the 25 hands with muscle atrophy before surgery, 6 hands were in group A, 5 hands were in group B, 1 hand was in group C, and 13 hands were in group D at final follow-up. Thenar muscle atrophy and denervation potentials were present before surgery in 13 of the 15 hands classified as group D at the final follow-up.

Effects of basic fibroblast growth factor on spontaneous resorption of herniated intervertebral discs. An experimental study in the rabbit

STUDY DESIGN

Histologic examination was performed on the autologous intervertebral disc material that was removed from the intervertebral space at L1-L2 and then relocated to the L4 posterior epidural space after the addition of basic fibroblast growth factor (bFGF) in a rabbit.

OBJECTIVES

To evaluate whether basic fibroblast growth factor influences the resorption process of the herniated intervertebral disc through the promotion of angiogenesis and chemotaxis.

SUMMARY OF BACKGROUND DATA

It has been reported that newly formed vessels, inflammatory cells, and their products may play an important role in the spontaneous resorption process of herniated intervertebral discs. In a rabbit model that mimics the sequestration type of intervertebral disc herniation, it has been reported that the autologous intervertebral disc material that relocated into the epidural space was penetrated by newly formed vessels originating from the epidural fat tissue. Therefore, it is possible that promotion of angiogenesis may influence the resorption of herniated intervertebral discs. Basic fibroblast growth factor is well known as an angiogenesis stimulation factor in vivo.

METHODS

Thirty-six adult rabbits were divided into three groups. The L1-L2 intervertebral disc was partially incised through a retroperitoneal approach in each rabbit. The harvested disc material, which contained nucleus pulposus and anulus fibrosus, was immersed in one of three kinds of solution before relocation into the posterior epidural space at L4. In the control group, the harvested intervertebral disc was immersed in physiologic saline for 2 hours before relocation. In the group receiving 5 micrograms bFGF, the disc was immersed in 5 micrograms/mL bFGF for 2 hours before the relocation. In the group receiving 20 micrograms bFGF, the disc was immersed in 20 micrograms/mL bFGF for 2 hours before the relocation. Rabbits of each group were killed for histologic examination 1, 2, 4, and 8 weeks after surgery.

RESULTS

In the bFGF-treated groups, newly formed vessels were observed to be in more numerous than those in the control group, 1 and 2 weeks after surgery. The number of inflammatory cells, including macrophages, lymphocytes, and fibroblasts, also increased in the bFGF-treated groups. The period from the surgery to the degradation of the intervertebral disc in the bFGF-treated groups was shorter than that in the control group, although the resorption process of the relocated discs was also observed in the control group. The size of relocated intervertebral discs in the bFGF-treated groups decreased at a higher rate than in the control group as time progressed. The rate of decrease in the size of discs in the group treated with 20 micrograms bFGF was more than that in the group treated with 5 micrograms.

CONCLUSIONS

Epidural injection of bFGF facilitated the resorption of the intervertebral disc relocated to the epidural space.

Chronic compartment syndrome of the lower leg: a new diagnostic method using near-infrared spectroscopy and a new technique of endoscopic fasciotomy

A 19-year-old female basketball player had chronic compartment syndrome. During basketball playing, she complained of bilateral lower leg pain that disappeared after several minutes of rest. The intracompartmental pressure in the anterior compartment was 41 mm Hg on the right side and 29 mm Hg on the left side immediately after playing. Prolonged ischemia of the anterior compartment was observed in comparison with four normal controls using near-infrared spectroscopy. Magnetic resonance imaging also revealed that the anterior compartment was mainly affected. Endoscopic fasciotomy was performed using an arthroscope, a transparent outer tube, and a retrograde blade. After the operation, her symptoms disappeared. Three months postoperatively, the anterior compartment pressure decreased and prolonged tissue ischemia improved. Endoscopic fasciotomy allowed us to cut the fascia safely and less invasively. We concluded that this technique is useful in treating chronic compartment syndrome in the anterior compartment of the lower leg.

Ultrasonographic analysis of shoulder rotator cuff tears

Seventy-nine shoulders suspected of rotator cuff tears were examined by ultrasonography (US) and forty-three received surgery. Long and short axis scans were performed and findings of each were separately classified according to a five-grade system, and the results were correlated with the actual extent of tear observed during surgery. Internal echogenicity and subacromial impingement were analyzed before and after surgery. A accuracy of US in detecting rotator cuff tears was analyzed. In addition, the correlation between cuff shape observed by US before surgery and actual shape observed during surgery was assessed. It was noted that cuff thinning and abnormalities in shape did not recover to normal after surgery. However, in the cases of discontinuities observed by US before surgery, US findings indicated that the torn cuff was anchored to the greater tuberosity and functional during active motion. Although post-operative US findings were not normal, clinical results were good in most cases. Sensitivity of US for detecting rotator cuff tear was 100% and specificity 94%. US is non-invasive, cost effective and allows the physician to examine the joint while it is in motion. Therefore, at this time, we use US as a screening method for detecting rotator cuff tears. Furthermore, US allows us to check for re-tears while the joint is in motion, which is essential for accurate diagnosis.

Three-dimensional appearance of Bowman's layer after radial keratotomy

PURPOSE

To examine the 3-dimensional collagen fibrillar architecture of Bowman's layer after radial keratotomy (RK).

SETTING

Department of Ophthalmology, Niigata University School of Medicine, Niigata, Japan.

METHODS

This study used monkey eyes in which 0.3 mm deep radial incisions were made on the cornea 2 weeks and 1, 6, and 12 months before the animals were killed. Corneal buttons were immersed in a fixative and the cells macerated with sodium hydroxide 10%. Scanning electron microscopy (SEM) was performed according to standard procedures. A part of the specimens was embedded in epoxy resin for light microscopic (LM) observation for comparison.

RESULTS

The 3-dimensional collagen fibrillar architecture of Bowman's layer was revealed by SEM. The rupture of Bowman's layer could be seen 12 months after surgery and there was no continuity of collagen fibrils in the ruptured area. In LM observations, the width of the stromal incisions gradually became narrower near 12 months after surgery.

CONCLUSION

Our cell-maceration/SEM method showed that the rupture of Bowman's layer remained up to 12 months after RK. This suggests that discontinuity of Bowman's layer may be responsible for globe rupture after RK.

Adequacy and long-term prognosis of endoscopic carpal tunnel release

Forty-one hands of 37 patients with idiopathic carpal tunnel syndrome treated by endoscopic carpal tunnel release (ECTR) were followed up for more than one year after surgery. Surgical results were evaluated using Kelly's criteria, the Semmes-Weinstein test, the static and moving 2-point discrimination tests, tip-pinch strength, and motor and sensory nerve conduction studies. Clinical results, according to Kelly's criteria three months after surgery, were excellent or good in 36 hands, and fair or poor in five hands. No recovery was evident at six months and 12 months after surgery in fair and poor hands. Based on these findings, we conclude that a neurolysis of the median nerve and release of constriction of the thenar muscle branch should be performed using the conventional open technique for patients with poor results three months after ECTR if the patients are dissatisfied with ECTR results.

Sintered bone implantation for the treatment of benign bone tumours in the hand

We report the results of treatment of benign bone tumours in the hand with curettage and sintered bone implantation using bovine sintered bone (True Bone Ceramics). There were 22 patients who underwent sintered bone implantation in our department in 1984 or later. The follow-up survey period varied from 9 months to 11 years and 2 months (mean, 5.8 years). Recurrence of tumours and complications such as infection or fracture were not observed, and there were no clinical symptoms. X-rays revealed new bone formation connecting the implanted blocks to bone. Sintered bone was not absorbed, and lucent zones around the implants or other abnormal findings were not observed. Bone union was achieved in all patients who had pathological fractures before surgery.

Anatomic relation between the medial collateral ligament of the elbow and the humero-ulnar joint axis

The anatomic relation between the proximal attachment of the medial collateral ligament of the elbow joint and the humero-ulnar joint axis has not been clearly shown in a published study. We examined cadaveric specimens to find the exact relation between them. The medial collateral ligament was microscopically dissected to isolate specific fiber bundles. The length of each bundle was measured with a charge-coupled device camera system that faced the medial side of the elbow joint. The measurements indicated that the projected length of the deep middle bundle of the anterior oblique ligament, which is the strong cord-like part of the medial collateral ligament, is isometric during elbow flexion. The proximal end of the deep middle bundle was thus considered to be located almost on the humero-ulnar joint axis.

Protective effect of quinaprilat, an active metabolite of quinapril, on Ca2+-overload induced by lysophosphatidylcholine in isolated rat cardiomyocytes

We examined the effects of quinaprilat, an active metabolite of quinapril (an angiotensin converting enzyme (ACE) inhibitor) on the increase in intracellular concentration of Ca2+ ([Ca2+]i) (Ca2+-overload) induced by lysophosphatidylcholine (LPC) in isolated rat cardiomyocytes. LPC (15 microM) produced Ca2+-overload with a change in cell-shape from rod to round. Quinaprilat but not quinapril at 20 or 50 microM attenuated the LPC-induced increase in [Ca2+]i and the change in cell-shape in a concentration-dependent manner. Since quinaprilat has an inhibitory action on ACE and quinapril has practically no inhibitory action on ACE, it is likely that the inhibitory action of quinaprilat on ACE is necessary for the protective effect of the drug against LPC-induced changes. We therefore examined the effects of enalapril (another ACE inhibitor with the weak inhibitory action on ACE) and enalaprilat (an active metabolite of enalapril with an inhibitory action on ACE) on the LPC-induced changes. Both enalapril and enalaprilat attenuated the LPC-induced Ca2+-overload, suggesting that the inhibitory action on ACE may not mainly contribute to the protective effect of ACE inhibitors against LPC-induced Ca2+-overload. This suggestion was supported by the fact that neither ACE (0.2 U/ml) nor angiotensin II (0.1-100 microM) increased [Ca2+]i in isolated cardiomyocytes. Furthermore, application of bradykinin (0.01-10 microM) did not enhance the protective effect of quinaprilat against LPC-induced changes. LPC also increased release of creatine kinase (CK) from the myocyte markedly, and quinaprilat but not quinapril attenuated the LPC-induced CK release. Unexpectedly, both enalapril and enalaprilat did not attenuate the LPC-induced CK release. Neither quinapril nor quinaprilat changed the critical micelle concentration of LPC, suggesting that these drugs do not directly bind to LPC. We conclude that quinaprilat attenuates the LPC-induced increase in [Ca2+]i, and that the protective effect of quinaprilat on the LPC-induced change may not be related to a decrease in angiotensin II production or an increase in bradykinin production.

Three-dimensional cytoarchitecture of rat pulmonary venous walls: a light and scanning electron microscopic study

The three-dimensional architecture of the rat pulmonary veins was studied by light microscopy (LM) and scanning electron microscopy (SEM). For LM, the left lungs were fixed with formalin, sectioned and immunostained with an anti-alpha-smooth muscle actin (alpha-SMA) antibody in addition to conventional staining. For SEM, the specimens were fixed with glutaraldehyde and immersed in 30% KOH solution for 8 min followed by treatment of collagenase solution for more than 5 h. By LM, the smooth muscle cells stained with anti-alpha-SMA showed discontinuous, periodical thickenings of circular bundles in the wall of the venules, but they became thin and continuous in the larger vessels (or veins) that had a cardiac muscle layer on the outside. Under SEM, the smooth muscle cells formed circular-oriented bundles at constant intervals along the venules less than 100 microm in diameter. These bundles had circumferential constrictions in the lumen. The cardiac muscle cells, which appeared in large pulmonary veins of more than 100 microm, ran in a circular or oblique direction and completely surrounded the vessel wall outside of the thin continuous layer of smooth muscle cells. The muscle arrangements were considered to play a significant role in the return blood flow in rat pulmonary veins.

Phospholipase A2 is not responsible for lysophosphatidylcholine-induced damage in cardiomyocytes

Lysophosphatidylcholine (LPC) is known to increase the intracellular concentration of Ca2+ ([Ca2+]i), leading to cell damage. In the present study we examined whether LPC activates phospholipase A2 (PLA2) and whether the activation of PLA2 is responsible for the LPC-induced cell damage in isolated rat cardiomyocytes. LPC (15 microM) produced an increase in [Ca2+]i, a change in cell shape from rod to round, and the release of creatine kinase (CK) accompanied by a significant elevation of the cellular level of nonesterified fatty acids (NEFA), especially arachidonic acid. Three PLA2 inhibitors, 7, 7-dimethyl-(5Z,8Z)-eicosadienoic acid (DEDA), 3-(4-octadecylbenzoyl)acrylic acid (OBAA), and manoalide, attenuated the LPC-induced accumulation of unsaturated NEFA to a similar degree. Nevertheless, whereas both DEDA and OBAA attenuated the LPC-induced increase in [Ca2+]i, change in cell shape, and release of CK, manoalide attenuated none of them. In the Ca2+-free solution, LPC did not increase [Ca2+]i with significantly less accumulation of NEFA, but it changed the cell shape from rod to round and increased the release of CK. These results suggest that exogenous LPC increases the PLA2 activity, which, however, may not be responsible for the LPC-induced damage in cardiomyocytes.

Effect of nonsteroidal anti-inflammatory drugs on lipid peroxidation by hydroxyl radical

1. Effects of acetaminophen and sodium salicylate on hydoxyl radical elimination were studied using an electron-spin-resonance spin-trapping method. The effects of these agents on lipid peroxidation of the human erythrocyte membrane were also investigated by the thiobarbituric acid method. 2. Acetaminophen and sodium salicylate depressed hydroxyl radical generated by Cu2+/H2O2. 3. Acetaminophen inhibited Cu2+/H2O2-dependent lipid peroxidation; however, sodium salicylate enhanced Cu2+/H2O2-dependent lipid peroxidation.

[A case report of dumbbell neurogenic tumor of the superior mediastinum]

A 15-year-old female was admitted because of the superior mediastinum mass on chest X-rays and sensory loss of ulnar side of the left arm. Computed tomographic scanning and magnetic resonance imaging revealed that the tumor was dumbbell-shaped and invaded the vertebral canal through the intervertebral foramen between C 7 and Th 1. At first laminectomy of vertebrae (C 6-Th 1) was made in a prone position and intra-spinal portion of the tumor was resected. Then the patient was placed in a supine position and the chest was opened by left hemicollar incision and sternotomy to the 2nd intercostal space. The tumor was divided into two parts at the level of 1st rib and completely removed. The pathological diagnosis was schwannoma. This procedure is safe and useful for dumbbell type tumor located in superior mediastinum, especially in case of large tumor from neck to the thoracic cavity.

Changes in the extracellular matrix on the surface of sintered bovine bone implanted in the femur of a rabbit: an immunohistochemical study

The interface of implanted True Bone Ceramics (TBC; sintered bovine bone; Koken, Tokyo, Japan) was examined. In the primary experiment, TBC was implanted into the bone marrow of a rabbit's femur. The extracellular matrices (types I, II, and III collagens and fibronectin) of decalcified specimens collected 1-48 weeks postoperatively were immunohistochemically examined. Undecalcified sections collected 6 weeks postoperatively were used for line analyses of calcium and phosphorus, by a scanning electron microscope-electron probe microanalysis (SEM-EPMA) method. In a secondary experiment, TBC was implanted into an osteochondral defect of a femoral condyle, harvested 1-12 weeks postoperatively, and decalcified to examine the extracellular matrices at the interface. In the bone marrow in the early phase, TBC had absorbed quantities of fibronectin. Immature bone (containing both types I and III collagens) in direct apposition to the ceramic surface had matured (containing type I collagen alone) in the TBC pores. SEM-EPMA revealed the continuity of high levels of calcium and phosphorus at the TBC-bone interface. In the secondary experiment, enchondral ossification or fibrous tissue formation was observed near the articular surface. However, in the subchondral layer, direct bone formation was observed in the TBC pores. It was concluded that TBC has excellent bioactivity for inducing maturation of new bone matrix on porous surfaces.

Ultrahigh-vacuum facility for high-resolution grazing-angle X-ray diffraction at a vertical wiggler source of synchrotron radiation

A versatile ultrahigh-vacuum chamber has been designed for grazing-angle X-ray standing-wave and diffraction experiments at the vertical wiggler source of the Photon Factory. Unlike at other sources, the vertically polarized X-rays from the wiggler favour the use of a horizontal scattering geometry. The X-ray chamber is equipped with a hemispherical beryllium window, which allows any scattering angle to be attained and secondary emissions to be measured. The chamber is of a compact design, sitting on a precision rotary table which is rotated for scans. Samples are introduced from a portable vessel. The whole procedure can be performed in a vacuum better than 10(-7) Pa. The system has successfully been applied to a grazing-angle X-ray standing-wave experiment, which determined the dimer bond length and the domain structure of Si(001) surfaces deposited with monolayer arsenic.

Possible mechanism of painful radiculopathy in lumbar disc herniation

The pathophysiologic mechanisms of painful radiculopathy caused by a herniated intervertebral disc remain unknown. This study sought to determine whether the autologous intervertebral disc produces pain related behavior and whether phospholipase A2 and nitric oxide are involved in the pathophysiologic mechanism producing the behavior. A rat model, in which autologous intervertebral discs were implanted on the nerve root in the lumbar spine, was used to measure hyperalgesia, which is a pain related behavior in the rat. In this experimental model, autologous nucleus pulposus and anulus fibrosus transplanted to lumbar nerve roots produced mechanical and thermal hyperalgesia, respectively. Epidural injection of a selective inhibitor for phospholipase A2 resulted in the disappearance of hypersensitivity to noxious mechanical stimuli. Thermal hyperalgesia produced by application of the anulus fibrosus was abated and abolished by epidural injections of saline and one of the inhibitors for nitric oxide synthase, respectively. The authors suggest that chemical mediators such as phospholipase A2 and nitric oxide, induced by extruded or sequestrated intervertebral discs, are involved in the pathophysiologic mechanisms of painful radiculopathy in lumbar disc herniations. This study may be useful in attempting to develop new medical approaches for treatments of lumbar disc herniation.

Protective effect of prazosin on the hydrogen peroxide-induced derangements in the isolated perfused rat heart

The effect of prazosin, an alpha1-selective adrenoceptor antagonist, on the hydrogen peroxide (H2O2)-induced mechanical and metabolic derangements was studied in the isolated rat heart, which was perfused aerobically by the Langendorffs technique at a constant flow rate and driven electrically. H2O2 (600 microM) produced both mechanical dysfunction (e.g., increase in the left ventricular end-diastolic pressure) and metabolic damage (e.g., decrease in the level of adenosine triphosphate) associated with lipid peroxidation (e.g., increase in the level of malondialdehyde). The H2O2-induced mechanical and metabolic derangements were attenuated by 2.5, 5, or 10 microM prazosin, and the increase in the level of malondialdehyde was attenuated by 5 or 10 microM prazosin. Nevertheless, prazosin had practically no effects on the mechanical function and energy metabolism of the H2O2-untreated normal heart at 2.5 or 5 microM, although it reduced the mechanical function at 10 microM. Prazosin was shown to have a hydroxyl radical scavenging effect. These results suggest that prazosin attenuates the H2O2-induced mechanical and metabolic derangements probably because of attenuation of the H2O2-induced lipid peroxidation in the heart.

A new approach to the development of anti-ischemic drugs: protective drugs against cell injury induced by lysophosphatidylcholine

Recent studies have revealed that lysophosphatidylcholine (LPC) produces mechanical and metabolic derangements in perfused working rat hearts and Ca2+-overload in isolated cardiac myocytes. Thus, LPC possesses an ischemia-like effect on the heart. Therefore, a drug that possesses an anti-LPC action would protect or improve ischemia/reperfusion damage. We examined the effects of various anti-ischemic drugs on the Ca2+ overload induced by LPC. Our data suggest that a drug with high lipophilicity possesses a protective effect on cell injury induced by LPC, probably because of preservation of membrane integrity.

Protective effects of ranolazine, a novel anti-ischemic drug, on the hydrogen peroxide-induced derangements in isolated, perfused rat heart: comparison with dichloroacetate

The effect of ranolazine, a novel anti-ischemic drug that stimulates the activity of pyruvate dehydrogenase, on hydrogen peroxide (H2O2)-induced mechanical and metabolic derangements was studied in isolated rat heart and compared with that of dichloroacetate (DCA), an activator of pyruvate dehydrogenase. The heart was perfused aerobically by the Langendorff's technique at a constant flow and driven electrically. H2O2 (600 microM) decreased the left ventricular developed pressure and increased the left ventricular end-diastolic pressure (i.e., mechanical dysfunction), decreased the tissue level of adenosine triphosphate (i.e., metabolic derangement), and increased the tissue level of malondialdehyde (MDA) (i.e., lipid peroxidation). These mechanical and metabolic derangements induced by H2O2 were significantly attenuated by ranolazine (10 or 20 microM). On the other hand, DCA (1 mM) was ineffective in attenuating the H2O2-induced mechanical and metabolic derangements. Ranolazine, however, did not modify the tissue MDA level, which was increased by H2O2. In the normal (H2O2-untreated) heart, ranolazine did not alter the mechanical function and energy metabolism. These results demonstrate that ranolazine attenuates mechanical and metabolic derangements induced by H2O2. It is suggested that the protective action of ranolazine against the H2O2-induced derangements is due to neither the energy-sparing, DCA-like, nor anti-oxidant effects.

Direct observation of t-butyl alcohol frozen and sublimated samples using low-vacuum scanning electron microscopy

Frozen biological specimens in t-butyl alcohol were examined under a low-vacuum environment in a "wet SEM" or "variable pressure SEM (scanning electron microscope)" equipped with a cooling stage and highly sensitive backscattered detector of the YAG type. After fixation with glutaraldehyde and osmium tetroxide, rat tissue blocks (tracheae and kidneys), and cultured human carcinoma cells were dehydrated with a graded series of t-butyl alcohol. The specimens were directly frozen on the cooling stage at -10 degrees C, evacuated to 20 Pa in the specimen chamber, and observed by detecting backscattered electrons at accelerating voltages of 5-6 kV. The images became clearer 20 min after the vacuum reached 20 Pa and revealed had good quality by 30 min, probably because t-butyl alcohol was sublimated during the time. The cilia of tracheal ciliated cells, end-feet of the podocytes of the renal glomerulus, and processes of cultured cells were clearly observed without any serious preparation artifacts. Since the low-vacuum SEM of t-butyl alcohol frozen samples is both simple and provides high imaging quality, it is expected to be useful in a variety of biological fields such as the rapid pathological diagnosis.

Effects of steroid and lipopolysaccharide on spontaneous resorption of herniated intervertebral discs. An experimental study in the rabbit

STUDY DESIGN

Histologic examination was performed on autografted intervertebral disc materials of rabbit models, which were partially incised through a retroperitoneal approach at L1-L2 and grafted within the posterior epidural space at L4.

OBJECTIVE

To evaluate whether the resorption process of the herniated intervertebral disc is influenced and controlled by treatments with medications.

SUMMARY OF BACKGROUND DATA

Regarding resorption of herniated intervertebral discs, recent studies of magnetic resonance images and histologic investigations of surgically resected specimens in lumber disc herniation patients have been reported. It has been shown that inflammatory factors may play an important role in the mechanism of resorption of the herniated intervertebral disc. However, little is known about the origin of newly formed vessels and inflammatory cells detected in herniated disc specimens from patients. In this study, The resorption process of disc material grafted into the epidural space was observed in a rabbit model.

METHODS

Thirty-six adult rabbits were used. The L1-L2 intervertebral disc was partially incised through a retroperitoneal approach. The harvested disc material, which contains the nucleus pulposus and the anulus fibrosus were placed into the posterior epidural space at L4 of the same rabbit. The animals were divided into control, and steroid groups. The control group received no treatment after surgery. In the lipopolysaccharide group, rabbits were injected 1 mg/kg into the peritoneum immediately and at 7 days after surgery. In the steroid group, rabbits were injected with 1 mg/kg betamethasone into the epidural space daily from 1 to 7 days after surgery. Rabbits of each group were killed for histologic examination at 1, 2, 4, and 8 weeks after surgery.

RESULTS

At 1 and 2 weeks after surgery, inflammatory cells and newly formed vessels were more frequently observed in the lipopolysaccharide group than in the control and steroid groups. At 4 weeks after surgery, derangement and loosening of collagen fibers were also observed in the lipopolysaccharide group. At 8 weeks after surgery, fragmentation and partial disappearance of matrix were observed in the control and lipopolysaccharide groups. Most of the intervertebral discs were replaced by fibrous tissues in the lipopolysaccharide group. However, the matrix of the intervertebral disc almost remained.

CONCLUSIONS

Autologous intervertebral disc material grafted into the epidural space was penetrated by newly formed vessels produced from the epidural fat tissue and resolved as the result of inflammatory reaction. Lipopolysaccharide accelerated the replacement of grafted intervertebral disc by fibrous tissue, which suggests the resorption of the disc in the epidural space of the rabbit, whereas high-dose steroid suppressed the replacement.

Propofol improves functional and metabolic recovery in ischemic reperfused isolated rat hearts

Propofol attenuates mechanical dysfunction, metabolic derangement, and lipid peroxidation by exogenous administration of H2O2 in the Langendorff rat heart. In this study, we examined the effects of propofol on mechanical and metabolic changes, as well as on lipid peroxidation induced by ischemia-reperfusion, in isolated, working rat hearts. Rat hearts (in control-modified Krebs-Henseleit bicarbonate buffer) were treated with two doses (25 microM and 50 microM) of propofol in an intralipid vehicle. In the first protocol, propofol was administered during the preischemic and reperfusion period, whereas in the second, it was only administered during the reperfusion period. Ischemia (15 min) decreased peak aortic pressure (PAOP), heart rate (HR), rate-pressure product (RPP), coronary flow (CF), and tissue concentrations of adenosine triphosphate (ATP) and creatine phosphate. After postischemic reperfusion (20 min), the CF and tissue concentration of ATP recovered incompletely; however, PAOP, HR, and RPP did not. Ischemia-reperfusion also increased the tissue concentration of malondialdehyde (MDA). In both protocols, both doses of propofol enhanced recovery of PAOP, HR, RPP, CF, and tissue concentration of ATP during reperfusion, and inhibited the tissue accumulation of MDA. These results indicate that propofol improves recovery of mechanical function and the energy state in ischemic reperfused isolated rat hearts, and the mechanism may involve the reduction of lipid peroxidation during postischemic reperfusion.

IMPLICATIONS

We evaluated the possible cardioprotective effects of propofol in isolated, working rat hearts subjected to 15-min ischemia, followed by 20-min reperfusion. We observed that propofol attenuated mechanical dysfunction, metabolic derangement, and lipid peroxidation during reperfusion. This latter finding seems to be one mechanism for cardioprotective effects of propofol.

Fibrous structure and connection surrounding the metacarpophalangeal joint

The fibrous components of the metacarpophalangeal (MP) joint including the palmar plate, the collateral ligament and the dorsal plate were studied with particular attention paid to the fibrous structure of the fibrous tendon sheath and the deep transverse metacarpal ligament. The tough fibrillar structure around the MP joint, especially the force nucleus, consisted of three types of mixed fibers: the fibrous tendon sheath of the A1 pulley, the deep transverse metacarpal ligament, and the palmar plate. The tendon sheath was located on the ulnar side in the index and middle fingers, on the central position in the ring finger, and on the radial side in the little finger. These fibrous connections among the fingers formed a transverse arch in the hand. The palmar plate of the MP joint was relatively rigid and appears to function as a cushion when flexed. A fold-like protrusion of the synovial layer of the palmar plate of the MP joint had a meniscoid function, which was larger than that of the proximal interphalangeal joint. The capsule of the MP joint was thicker at the dorsal area, forming a dorsal plate, which is a sliding floor of the extensor mechanism and has a meniscoid function for joint congruity. The main lateral stabilizer consisted of collateral ligaments and accessory collateral ligaments anchored to the palmar plate. These structures act together as a "phalangeal cuff", connecting the proximal phalanx to the metacarpal head and stabilizing the MP joint.

Low-voltage backscattered electron imaging of non-coated biological samples in a low-vacuum environment using a variable-pressure scanning electron microscope with a YAG-detector

A variable-pressure scanning electron microscope (VP-SEM) equipped with a high-sensitive backscattered electron (BSE) detector of the YAG type was applied to studies of biological tissue samples. The rat kidney and trachea were fixed, dehydrated in ethanol, critical point-dried and examined in the VP-SEM under a specimen chamber pressure of 1 to 150 Pa. The high-resolution surface images of the non-coated specimens were obtained in a low-vacuum (1-20 Pa) environment at an accelerating voltage of 5 kV, while the images at 10-20 kV contained information beneath the surface of the specimens. The observation in the VP-SEM equipped with YAG detector in a low-vacuum (1-20 Pa) environment at low (3-5 kV) accelerating voltages is useful for the three-dimensional analysis of the surface morphology of biological non-coated samples.

Carpal tunnel syndrome induced by two types of calcium deposition

Two rare cases of carpal tunnel syndrome caused by calcification in the carpal tunnel are reported. One case involved a tumorous calcification consisting of basic calcium phosphate, and the other involved a diffuse calcification consisting of a mixture of calcium pyrophosphate dihydrate and basic calcium phosphate. These cases suggest that the shape of carpal tunnel calcifications is influenced by the nature of calcifying substance itself, i.e., whether it is heterogenous or homogenous.

Protective effect of amiloride against reperfusion damage as evidenced by inhibition of accumulation of free fatty acids in working rat hearts

To examine whether amiloride protects against ischemia-induced or reperfusion-induced damage to the heart, mechanical and metabolic studies were performed in the isolated, working rat heart. Ischemia decreased both mechanical function and the tissue levels of high-energy phosphates and increased the tissue levels of free fatty acids (FFAs). Reperfusion restored the levels of high-energy phosphates but further increased FFA accumulation. For this reason, accumulation of FFAs was used as an indicator of both ischemia-induced and reperfusion-induced damage. Drugs were added to the perfusion solution 5 min before ischemia until the end of ischemia (pre) or until 10 min after reperfusion (pre + post). Diltiazem (1 or 5 mumol/L pre) decreased the mechanical function of the non-ischemic heart and attenuated both ischemia-induced and reperfusion-induced accumulation of FFAs. Amiloride (50 mumol/L pre) did not affect the mechanical function of the non-ischemic heart or attenuate ischemia-induced or reperfusion-induced FFA accumulation effectively. However, amiloride (50 mumol/L pre + post) did markedly attenuate the reperfusion-induced accumulation of FFAs. In conclusion, diltiazem attenuates both ischemia-induced and reperfusion-induced myocardial damage, probably through its energy-sparing effect as a result of a decrease in mechanical function before ischemia. In contrast, amiloride attenuates only the reperfusion-induced myocardial damage through mechanisms other than the energy-sparing effect.

Palmitoyl-L-carnitine modifies the myocardial levels of high-energy phosphates and free fatty acids

Long-chain acylcarnitines, such as palmitoyl-L-carnitine (PALCAR), are known to accumulate in the myocardium during ischemia. We examined whether exogenous PALCAR modifies the myocardial levels of high-energy phosphates (HEP) and free fatty acids (FFA) in the heart, and whether d-cis-diltiazem and l-cis-diltiazem, an optical isomer having less potent Ca2+ channel blocking action than d-cis-diltiazem, attenuate the PALCAR-induced myocardial changes. Rat hearts were perfused aerobically at a constant flow according to the Langendorff's technique, while being paced electrically. PALCAR (5 microM) decreased the tissue levels of adenosine triphosphate and creatine phosphate and increased the tissue level of adenosine monophosphate, and produced mechanical dysfunction. In addition, PALCAR (5 microM) increased markedly the tissue levels of FFA, especially those of arachidonic and palmitoleic acids, and the release of creatine kinase (CK) from the myocardium. These alterations in the myocardial levels of HEP and FFA induced by PALCAR were significantly attenuated by d-cis-diltiazem (15 microM) or l-cis-diltiazem (15 microM). Both drugs also attenuated the PALCAR-induced CK release. The present study demonstrates that PALCAR modifies the tissue levels of HEP and FFA in the heart and that both d-cis- and l-cis-diltiazem protect the myocardium against the PALCAR-induced changes through mechanisms other than Ca2+ channel blocking action.

Muscle strength in rheumatoid elbow: quantitative measurement and comparison to Larsen's X-ray grade

Accurate assessment of elbow function is important to determine the total ability of the arm. The purpose of this study was to clarify the relationship between isometric muscle strength of the elbows of patients with rheumatoid arthritis (RA) and Larsen's X-ray evaluation. Fifty-six elbows of 45 RA patients aged 47 to 77 years (mean age, 63 years) were tested. Muscle strength was measured with an isometric torque-cell dynamometer. Test-retest reliability of the dynamometer was proven by measuring 12 elbows of 6 healthy young men. In RA patients, elbow flexion and extension strength decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 4. However, Grade 5 elbows had greater muscle strength than those in Grade 4. Forearm pronation and supination strength also decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 5. This quantitative study made it clear that the muscle strength of RA patients' elbows almost completely correlates to X-ray finding according to the grade of Larsen's evaluation based on X-rays. With regard to muscle strength of postoperative elbows, both flexion strength and supination strength after total elbow replacement (TER) were about two times greater than before TER, and after synovectomy it was as great as those in non-operative RA patients of Grade 2.

Osteoporosis due to testicular atrophy in male leprosy patients

A study was conducted to examine the relationship of testicular atrophy to bone metabolism in male leprosy patients. The study consisted of 31 leprosy patients (mean age: 62.0 years) and 31 healthy control men (mean age: 60.0 years). Measurements were made of their serum levels of free testosterone (FT), estradiol (E2), luteinizing hormone (LH) and 25-hydroxyvitamin D (25 OHD). Bone mineral density (BMD) was measured at radial sites and the lumbar vertebral bodies (L2-L4) by dual-energy X-ray absorptiometry using a Hologic QDR-2000 densitometer. FT and E2 levels were significantly lower and LH levels higher in leprosy patients than in controls. This represents a primary hypogonadal pattern. A value of 7.20 pg/ml of FT ( = Mean - 1 SD of control) was used as a cut off value, and the subjects were subdivided into a hypogonadal group (HG) and a non hypogonadal group (non-HG). When the subjects were compared for differences in age, age at onset of disease, duration of disease, body mass index and BMD, only the duration of disease and BMD were significantly different between the two groups. Furthermore, BMD of the forearm significantly correlated with FT levels (r = 0.689, P < 0.0001). Low BMD may be due to orchitis and testicular atrophy.

Antithrombotic effects of 3-([1:1',2':1"]-3'-terphenyl)propanol in animals

3-([1:1',2':1"]-3'-Terphenyl)propanol (CAS 186835-06-3, F050) and acetylsalicylic acid (ASA) inhibited platelet aggregation induced by CaCl2, arachidonic acid, collagen, adenosine diphosphate (ADP) and thrombin in guinea pigs, rabbits and rats in vitro. However, F050 had a wider spectrum of actions than ASA. Orally administered F050 inhibited platelet aggregation ex vivo. F050 significantly reduced the thrombus formation in the extracorporeal circulation thrombosis model in guinea pigs. It inhibited erythrocyte hemolysis induced by hypotonic NaCl, while ASA did not. F050, but not ASA, inhibited increases in platelet [CA2+]i caused by thrombin in guinea pigs. F050 is a parent compound that will facilitate the development of an orally active drug for the treatment of thrombotic diseases.

FRACTURES OF THE BASE OF THE MIDDLE PHALANX OF THE FINGER

We classified fractures of the base of the middle phalanx into five types: 1) single palmar fragment; 2) single dorsal fragment; 3) two main fragments; 4) not involving the articular surface, including epiphyseal separation in children; and 5) all others. Types 1 and 2 were subclassified into avulsion, split and split-depression.

Surgery is recommended for unstable type-1 avulsion fractures, type-2 avulsions which may develop buttonhole deformities, and all fractures which displace articular cartilage surfaces. Long-term follow-up showed that surgical treatment which produced good stability and congruity gave good results. These should be the primary aims of treatment.

Fractures of the base of the middle phalanx of the finger. Classification, management and long-term results

We classified fractures of the base of the middle phalanx into five types: 1) single palmar fragment; 2) single dorsal fragment; 3) two main fragments; 4) not involving the articular surface, including epiphyseal separation in children; and 5) all others. Types 1 and 2 were subclassified into avulsion, split and split-depression. Surgery is recommended for unstable type-1 avulsion fractures, type-2 avulsions which may develop buttonhole deformities, and all fractures which displace articular cartilage surfaces. Long-term follow-up showed that surgical treatment which produced good stability and congruity gave good results. These should be the primary aims of treatment.

Differential effects of Ca2+ channel blockers on Ca2+ overload induced by lysophosphatidylcholine in cardiomyocytes

The effects of Ca2+ channel blockers (verapamil, diltiazem, nicardipine, bepridil and flunarizine) on Ca2+ overload induced by lysophosphatidylcholine were examined in rat isolated cardiomyocytes. Addition of lysophosphatidylcholine (15 microM) produced Ca2+ overload as evidenced by a marked increase in the concentration of intracellular Ca2+ and hypercontracture of cells. Verapamil, flunarizine and bepridil concentration dependently inhibited the lysophosphatidylcholine-induced Ca2+ overload, whereas diltiazem and nicardipine did not. Lysophosphatidylcholine increased the release of creatine kinase, which was significantly attenuated by verapamil, flunarizine or bepridil (5 microM for each), but not by diltiazem or nicardipine (20 microM for each). Verapamil, flunarizine, bepridil (which attenuated the lysophosphatidylcholine-induced Ca2+ overload) and nicardipine (which did not) inhibited the veratridine-induced increase in the concentration of intracellular Na+ (indicated by the increase in fluorescence ratio of Na(+)-binding benzofuran isophthalate) and cell contracture, whereas diltiazem did not. These results suggest that verapamil, bepridil and flunarizine attenuate the Ca2+ overload induced by lysophosphatidylcholine, and that the Ca2+ channel blocking action of these drugs does not contribute substantially to this effect. The Na+ channel inhibition together with high lipophilicity of these drugs may be important for the attenuation of the lysophosphatidylcholine-induced Ca2+ overload.

Hair cycle-dependent expression of heat shock proteins in hair follicle epithelium

BACKGROUND

Heat shock proteins (HSPs) have a physiologic function in unstressed cells, which is believed to include a role as a "molecular chaperone." The hair cycle is characterized by rhythmic tissue remodelling processes, and is an intriguing model for studying the relation between keratinocyte differentiation and HSP expression under physiologic circumstances. We have therefore studied, by immunofluorescence, the expression of selected HSPs during the murine hair cycle.

METHODS

The association between hair follicle cycling and the expression of three selected HSPs (HSPs 27, 60, and 72) was examined by immunofluorescence, using the depilation-induced hair cycle of C57BL/6 mice.

RESULTS

HSP expression was absent from telogen follicles, and was restricted predominantly to keratinocytes in the bulge and the cycling epithelial portion of the hair follicle during anagen and catagen. Immunoreactivity for HSPs 27, 60, and 72 in the hair bulb increased significantly during anagen VI and the catagen transformation of the follicle, and decreased again abruptly with completion of the catagen-telogen transformation. The expression pattern of HSPs 60 and 72 in situ was cytoplasmic, whereas that of HSP 27 was both cytoplasmic and nuclear.

CONCLUSIONS

These observations suggest that the synthesis of HSPs by hair bulb keratinocytes is related to the anagen-catagen transformation of the follicle, possibly reflecting keratinocyte apoptosis and/or terminal differentiation in the regressing, cycling portion of the follicle. In addition, the rather proximal localization of HSP expression makes it unlikely that the HSPs examined interact with the more distally located intrafollicular gamma/delta T-cell receptor-positive lymphocytes.

Protective effects of dilazep and its derivative K-7259 on the haemolysis induced by amphiphiles in rat erythrocytes

The effects of dilazep and K-7259, a dilazep derivative, on the haemolysis (as evidenced by release of haemoglobin) induced by palmitoyl-L-carnitine (PAL-CAR) or palmitoyl 1-alpha-lysophosphatidylcholine (PAL-LPC) have been determined in rat erythrocytes. At concentrations above the critical micelle concentration both PAL-CAR and PAL-LPC induced haemolysis; the concentrations of PAL-CAR and PAL-LPC producing 50% haemolysis were approximately 13 and 14 microM, respectively. The 50% haemolysis induced by PAL-CAR or PAL-LPC was attenuated by dilazep (1, 10 or 100 microM) but not at the highest concentration used (1 mM). K-7259 attenuated the 50% haemolysis induced by PAL-CAR or PAL-LPC at concentrations ranging from 1 microM to 1 mM. Similarly, dilazep (1 to 100 microM) and K-7259 (1 microM to 1 mM) significantly or insignificantly attenuated the 25% and 75% haemolysis induced by PAL-CAR or PAL-LPC. Neither dilazep nor K-7259 affected micelle formation by PAL-CAR or PAL-LPC, nor, at concentrations of 1 and 10 microM, did they attenuate the haemolysis induced by osmotic imbalance (hypotonic haemolysis). These results suggest that both dilazep and K-7259 protect the erythrocyte membrane from the damage induced by PAL-CAR or PAL-LPC. The protective effects of dilazep and K-7259 are mediated by some mechanism other than prevention of micelle formation or protection of the erythrocyte membrane against osmotic imbalance.

Detection of mineral density on the surface of mouse parietal bones: backscattered electron imaging of low accelerating voltage scanning electron microscopy

Backscattered electron (BSE) imaging of scanning electron microscopy (SEM) was applied to a study on the mineral density of the bone surface. The neonatal and adult mouse parietal bones freed of the periosteum and covering cells were examined in a field emission scanning electron microscope equipped with a high sensitivity BSE detector at 1-30 kV accelerating voltages. The mineral density of the bone surface was observable in BSE images at 5 kV accelerating voltage while only the topographic structures of the surface were obtained under an accelerating voltage less than 5 kV. As the accelerating voltages increased from 5 kV, the bright areas were extended, probably due to the imaging of the calcified bone matrix under the uncalcified osteoid. The bone surface is usually divided into smooth and rough areas according to its irregularities. BSE images at 5 kV clearly showed that the smooth areas were further divided into dark and bright areas which apparently corresponded to the uncalcified osteoid and calcified bone matrix, respectively. Bright granules, about 1.0-3.0 microns in diameter, were sometimes observed at the border between the osteoid and calcified bone matrix; these granular calcified areas were regarded as the calcifying front forming the calcified bone matrix from the osteoid. The present study demonstrated that the distribution of the osteoid on the mouse parietal bone surface changes depending on age: the osteoid occupied a large area in the parietal bone surface in neonatal mice, but was small in adult mice. Thus, low accelerating voltage SEM using BSE provides new information on the distribution of the osteoid and the bone matrix calcification under both normal and pathological conditions.

Percutaneous release for trigger finger in idiopathic and hemodialysis patients

Sixty-seven trigger fingers of 58 idiopathic and hemodialysis patients were treated by percutaneous A1-pulley release technique. Severity of triggering was classified into five grades for treatment selection and prediction of possible results. Results were excellent in 41 fingers, good in 9, fair in 7, and poor in 10, requiring additional treatment. The results of the lower grades were better, and those of the higher grades were poor. Excellent or good results appeared to depend on the proper selection of the patients according to the grading system and confirmation of triggering disappearance just after the release. There were neither infections nor neuro-vascular deficits after treatment. Compared to conventional open release, this treatment was found to be more useful from the standpoints of ease and safety of the technique, and the patients' quick return to normal life.

Beneficial effects of dilazep on the palmitoyl-L-carnitine-induced derangements in isolated, perfused rat heart: comparison with tetrodotoxin

The present study was carried out to determine the effect of dilazep, having an inhibitory effect on the Na+ channel, on the mechanical dysfunction and metabolic derangements induced by palmitoyl-L-carnitine in isolated rat heart and to compare the effect of dilazep with that of tetrodotoxin, a specific inhibitor of the Na+ channel. Rat hearts were perfused aerobically at a constant flow according to Langendorff's technique and paced electrically. Palmitoyl-L-carnitine (5 microM) decreased the left ventricular developed pressure and increased the left ventricular end diastolic pressure (i.e., it produced mechanical dysfunction), decreased the tissue level of adenosine triphosphate and increased the tissue level of adenosine monophosphate (i.e., it produced metabolic derangements). These mechanical and metabolic alterations induced by palmitoyl-L-carnitine were attenuated by either dilazep (1 microM) or tetrodotoxin (3 microM). On the other hand, neither dilazep nor tetrodotoxin modified the mechanical function and energy metabolism of the normal (palmitoyl-L-carnitine-untreated) heart. These results suggest that inhibition of the Na+ channel with dilazep or tetrodotoxin is responsible, at least in part, for attenuating the palmitoyl-L-carnitine-induced mechanical dysfunction and metabolic derangements in the heart.

The role of phospholipase A2 and nitric oxide in pain-related behavior produced by an allograft of intervertebral disc material to the sciatic nerve of the rat

STUDY DESIGN

To elucidate the pathomechanisms of radicular pain secondary to lumbar disc herniation.

OBJECTIVES

To evaluate whether intervertebral disc material applied to the sciatic nerve produces hyperalgesia, and if the hyperalgesia in influenced by inhibitors of phospholipase A2 and nitric oxide synthase.

SUMMARY OF BACKGROUND DATA

Previously, the authors reported that application of nucleus pulposus and anulus fibrosus material to the lumbar epidural space produces different forms of hyperalgesia (mechanical versus thermal), with different and distinct histologic changes. Additional pharmacologic studies showed that phospholipase A2 and nitric oxide are involved in the mechanisms that produce the mechanical and thermal hyperalgesia, respectively, N omega-nitro-L-arginine methyl ester and mepacrine are relatively selective inhibitors of nitric oxide synthase and phospholipase A2, respectively. However, it is not known what the relation is between the hyperalgesia produced and the activation and involvement of phospholipase A2 and production of nitric oxide, or why the application of nucleus pulposus and nucleus pulposus with anulus fibrosus produces different types of hyperalgesia.

METHODS

Experiments were performed in five groups of rats: The control group (no treatment), the sham group (exposure of the sciatic nerve only), the fat group (allografted fat on the sciatic nerve), the nucleus pulposus group (allografted nucleus pulposus) and the nucleus pulposus + anulus fibrosus group (allografted nucleus pulposus and anulus fibrosus). Withdrawal threshold and latency from mechanical pressure and a radiant heat to hind paws were measured preoperatively and postoperatively. After local sciatic nerve administration of N theta-nitro-L-arginine methyl ester or mepacrine into the operated site, sensitivities to noxious stimuli were reevaluated after treatment.

RESULTS

Only rats in the nucleus pulposus group showed evidence of mechanical hyperalgesia. However, injection of N theta-nitro-L-arginine methyl ester resulted in evidence of mechanical hyperalgesia in the nucleus pulposus + anulus fibrosus group. Mechanical hyperalgesia was produced in the nucleus pulposus group and after injection of N theta-nitro-L-arginine methyl ester in the nucleus pulposus+anulus fibrosus group, both of which returned to normal after mepacrine injection. There were no significant changes in sensitivity to thermal stimuli in any of the experimental groups.

CONCLUSION

It appears that phospholipase A2 and nitric oxide play important but different roles in pathomechanisms of radicular pain in lumbar disc herniation.

Histochemical demonstration of nitric oxide in herniated lumbar discs. A clinical and animal model study

STUDY DESIGN

This study was designed to localize the cells that produce nitric oxide in a lumbar disc herniation by histochemical method, including in situ hybridization.

OBJECTIVE

To clarify which cells in herniated lumbar discs produce nitric oxide.

SUMMARY OF BACKGROUND DATA

It was reported that herniated lumbar intervertebral disc specimens in culture are capable of producing nitric oxide.

METHODS

Surgical specimens from lumbar disc herniation were examined to determine nitric oxide synthase histologically using nicotinamide adenine dinucleotide phosphate diaphorase histochemistry. Allografts of intervertebral disc materials were placed on the epidural space at L6 level in the rat. Nitric oxide synthase was examined in the applied tissues using nicotinamide adenine dinucleotide phosphate diaphorase histochemistry and in situ hybridization histochemistry.

RESULTS

Nicotinamide adenine dinucleotide phosphate diaphorase (nitric oxide synthase) positive cells were observed in 2 (40%) of 5 herniated disc materials in patients. The positive cells were mainly in granulation tissue around intervertebral disc materials. In animal models, nitric oxide synthase-positive cells were observed in all specimens at 1 and 2 weeks postoperatively. Newly formed vessels and small round cells in granulation tissue around the grafted intervertebral disc showed positive reaction. In situ hybridization demonstrated the expression of inducible isoform of nitric oxide synthase messenger RNA (mRNA) identical to small round cells around the applied intervertebral disc.

CONCLUSION

Nitric oxide in a lumbar disc herniation is mainly produced by cells in granulation tissue around the herniated intervertebral disc.

X-ray reflectivity at the L edges of Gd

Preparations are underway for the experimental investigation of the roughness of magnetic interfaces in rare-earth multilayers by combining the grazing-angle X-ray scattering technique with the resonant magnetic scattering of hard X-rays. Theoretical considerations show that for small scattering angles, 2theta, the asymmetry ratio, A = [I(+) - I(-)]/[I(+) + I(-)], depends on 2theta and varies as 1/cos theta. The first step towards the goal of determining the magnetic roughness has been taken by measuring the chemical roughness (via specular reflectivity) of a Gd thin-film sample at five photon energies close to the L(3) absorption edge, which yielded the dispersion corrections, f' and f'', to the Gd atomic form factor in good agreement with the calculation of Cromer & Liberman [J. Chem. Phys. (1970), 53, 1891-1898].

Cardioprotective effect of K-7259, a novel dilazep derivative, against ischemia-reperfusion damage in isolated, working rat hearts

Global ischemia (15 min) followed by reperfusion (10, 20 or 30 min) was performed in isolated, working rat hearts. Ischemia depressed mechanical function, which was not restored by reperfusion of 20 min. Preischemic administration of K-7259 (N,N'-bis[4-(3,4,5-trimethoxyphenyl)butyl]homopiperazine dihydrochloride) (1, 5 or 10 microM) decreased the function before ischemia, but it attenuated the ischemia-induced dysfunction during reperfusion (20 min). Postischemic administration of K-7259 (10 microM) or dilazep (20 microM) also attenuated the ischemia-induced dysfunction during reperfusion (30 min). Ischemia-reperfusion (10 min) increased the tissue malondialdehyde level, and postischemic administration of K-7259 (10 microM) or dilazep (20 microM) attenuated the malondialdehyde accumulation. K-7259 has a cardioprotective effect when given either before or after ischemia.

Histopathology and clinical results of carpal tunnel syndrome in idiopathic cases and hemodialysis patients

The results of the histological examinations of specimens of the tenosynovium of the flexor tendon, the epineurium and the transverse carpal ligament from two groups of Japanese patients with carpal tunnel syndrome (idiopathic and hemodialysis) were compared. Amyloid deposits, positively identified as beta 2-microglobulin, appeared in all patients in the long-term hemodialysis group, but in no patients in the idiopathic group. Although the pathogenesis differed between the two groups, both resulted in nerve compression in the carpal tunnel. Therefore, surgical release is considered beneficial for both groups.

Endoscopic carpal tunnel pressure measurement: a reliable technique for complete release

Carpal tunnel syndrome is diagnosed by clinical symptoms, Tinel's sign, Phalen's test and electromyography. Carpal tunnel pressure measurement can also aid in the precise identification of excessive pressure sites that indicate locations for release. In this study, pressure measurements made during endoscopic carpal tunnel release at 5 points were significantly higher anywhere in the carpal tunnel than outside the tunnel and decreased markedly after release. We concluded that our measurement technique can improve the reliability of endoscopic carpal tunnel release by decreasing the likelihood of missing any nerve entrapment sites.

Guyon's canal syndrome. A different clinical presentation caused by an atypical fibrous band

An atypical case of Guyon's canal syndrome is reported. A 40-year-old woman with hypoaesthesia and claw-finger deformity of the little finger, hypothenar muscle atrophy but no first dorsal interosseous muscle atrophy, underwent release of a fibrous band to decompress the ulnar nerve at the deep branch just proximal to the branch to the abductor digiti minimi muscle. The claw-finger deformity recovered 1 week after surgery.

The central slip attachment fracture

Eight displaced central slip attachment fractures were treated by open reduction and internal fixation to avoid boutonniere deformity, to reduce the fracture anatomically and to allow early mobilization of the joint. This injury should be recognized as a disruption of the dynamic extensor mechanism associated with an intraarticular fracture, fracture-dislocation or soft tissue injury of the PIP joint. We have grouped central slip attachment fractures into three types according to the mechanism of injury, with suggested methods of treatment.