The lateral approach compared with the volar approach for exposure of the hook of the hamate

Two cases of delayed union of the hook of the hamate were satisfactorily treated by excisional surgery. The volar surgical approach through the palm is common, but to expose the hook some hypothenar muscles and cardinal ligaments must be divided. Care must be taken to avoid injury of the motor and sensory branches of the ulnar nerve that occur close to the hook. The lateral approach between the abductor digiti minimi muscle and the fifth metacarpal bone is easier and less traumatic. This approach is also safer for the ulnar neurovascular bundle, which is protected by volar retraction and the hypothenar muscles. The lateral approach is advantageous unless the injury is complicated by ulnar nerve palsy or flexor tendon injury.     

Human T cell leukemia virus-I carriers and gonarthrosis. A preliminary report.

Gonarthrosis in 11 human T cell leukemia virus-1 (HTLV-I) carriers were studied for sera, synovial fluids (SF) and cerebrospinal fluids (CSF). Atypical lymphocytes similar to adult T cell leukemia cells were noticed in the SF of all the HTLV-I carriers and ranged from 19 to 1%, while those of peripheral white blood cells ranged from 3 to 0%. Anti-HTLV-I antibodies in the SF were equal to or lower than those in the sera. The CSF from 7 of them demonstrated positive titers of anti-HTLV-I antibodies, while no evidence of neurological disorders manifested. The histopathological findings of synovial membranes on hematoxylin and eosin staining method showed no statistical difference between those of gonarthrosis of HTLV-I carriers and noncarriers.     

Ultrastructural study of articular cartilage in experimental pyogenic arthritis

Ultrastructural changes of the articular cartilage at the early stage of experimental pyogenic arthritis were studied by electron microscopy. The superficial zone of the cartilage at the site of the cartilage-synovium junction demonstrated far more changes than those at the site of the free surface of the articular cartilage. Changes were observed at the cartilage-synovium junction as early as four hours after the intraarticular injection of the infecting organism. The most interesting finding was migration of erythrocytes and polymorphonuclear leucocytes into the superficial zone of the cartilage at the early stage. The pericellular matrix in the middle zone became so loose in some areas that collagen fibrils were partially exposed after three days. The naked collagen fibrils were tapered, nicked and irregular in size after seven days.     

Bipolar hip arthroplasty in rheumatoid arthritis

Bipolar hip arthroplasty with bone grafting was performed on 25 joints with rheumatoid arthritis from 1981 to 1985. The results and roentgenographical progress of the grafted bone were followed for a minimum of two years, the longest follow-up examination occurring six years after the operation. The clinical score was assessed by the hip rating score of the Japanese Orthopaedic Association, which assigns a maximum of 100 points. The preoperative clinical score ranged from 22 to 59 points (mean, 42.6). The postoperative score improved to a range of 65-92 points (mean, 72.8). Of 24 hips examined, 21 (87.5%) were painless. As measured serially from the roentgenograms made immediately after the operation, the overall distance of central migration in 24 hips was 0-8.5 mm (average, 2.7 mm). The overall distance of superior migration in 24 hips was 0-10 mm (average, 3.7 mm). A single massive bone graft using extracted femoral head was considered to be better than bone fragments as the procedure for acetabular reconstruction during bipolar hip arthroplasty in rheumatoid arthritis.     

Geometric total knee arthroplasty--follow-up for an average of six years

Geometric total knee prosthesis was applied for reconstruction of 70 destructive knee joints in 56 patients from November 1973 through March 1979. The average follow-up period extended to six years and seven months. Eleven patients had died and four could not be located. Eighty-one percent of the remaining arthroplasties disclosed little or no pain at the time of the review. Pain in the patellofemoral joints was an insignificant problem in this series. The absence of radiolucent zone at the tibial cement-bone interface was noted in only 20.4% of the roentgenograms. New formation or progression of radiolucent zone after six months was found in 36.7%. Displacement of the marker wires seen in serial roentgenograms existed in 51.0% of the knees. The tibial component was fractured in one patient.     

PKCη deficiency improves lipid metabolism and atherosclerosis in apolipoprotein E‐deficient mice

Genomewide association studies have shown that a nonsynonymous single nucleotide polymorphism in PRKCH is associated with cerebral infarction and atherosclerosis‐related complications. We examined the role of PKCη in lipid metabolism and atherosclerosis using apolipoprotein E‐deficient (Apoe^?/?) mice. PKCη expression was augmented in the aortas of mice with atherosclerosis and exclusively detected in MOMA2‐positive macrophages within atherosclerotic lesions. Prkch^+/+Apoe^?/? and Prkch^?/?Apoe^?/? mice were fed a high‐fat diet (HFD), and the dyslipidemia observed in Prkch^+/+Apoe^?/? mice was improved in Prkch^?/?Apoe^?/? mice, with a particular reduction in serum LDL cholesterol and phospholipids. Liver steatosis, which developed in Prkch^+/+Apoe^?/? mice, was improved in Prkch^?/?Apoe^?/? mice, but glucose tolerance, adipose tissue and body weight, and blood pressure were unchanged. Consistent with improvements in LDL cholesterol, atherosclerotic lesions were decreased in HFD‐fed Prkch^?/?Apoe^?/? mice. Immunoreactivity against 3‐nitrotyrosine in atherosclerotic lesions was dramatically decreased in Prkch^?/?Apoe^?/? mice, accompanied by decreased necrosis and apoptosis in the lesions. ARG2 mRNA and protein levels were significantly increased in Prkch^?/?Apoe^?/? macrophages. These data show that PKCη deficiency improves dyslipidemia and reduces susceptibility to atherosclerosis in Apoe^?/? mice, showing that PKCη plays a role in atherosclerosis development.     

Changes in masseter muscle blood flow during voluntary isometric contraction in humans

The effect of jaw clenching on local blood flow in the masseter muscle was measured using the hydrogen clearance method in 13 healthy subjects. Sustained isometric masseter-muscle contraction levels of 25 and 50% of maximum voluntary contraction (MVC) were investigated. The blood flow at 25% MVC before contraction, during contraction and after contraction was 12.3 +/- 10.9, 19.2 +/- 12.1 and 78.8 +/- 63.9 mL min(-1) (100 g)(-1) (mean +/- s.d.), respectively. At 50% MVC, it was 14.2 +/- 12.9, 18.6 +/- 10.0 and 80.1 +/- 61.8, respectively. The volume of blood flow was significantly greater after contraction as compared with before contraction at both levels (P < 0.0001) and there was no significant difference between before and during contraction periods (P = 0.17: 25% MVC; P = 0.38: 50% MVC). At 50% MVC blood flow before contraction and the difference in blood flow before and during contraction showed significant negative correlation (r = -0.636, P < 0.02). When the volume of blood flow was low before contraction it tended to increase during contraction and decreased when it was high before contraction. These findings indicate that blood flow in the masseter muscle during sustained isometric contraction is affected by the condition of contraction and may be influenced by the muscle region. It was also indicated that the blood flow during high level contraction was influenced by the volume of blood flow before contraction. Clinically, our findings may help to understand pathological changes which may lead to chronic masticatory muscle pain.     

The relationship between retrieval success and task performance during the recognition of meaningless shapes: an event-related near-infrared spectroscopy study

Retrieval success of episodic memory has been studied intensively through the investigation of old/new effects. Recognized stimuli used in event-related functional magnetic resonance imaging studies on old/new effects have been words and visual materials which can evoke semantic associations. To elucidate the neural basis of retrieval success uninfluenced by semantic processing, we investigated the correlation between old/new effects and task performance during the recognition of meaningless shapes, by using event-related near-infrared spectroscopy. Forty-two right-handed subjects made recognition judgments about old (studied) or new (unstudied) meaningless shapes. The old/new effects of the shapes were positively correlated with task performance in the bilateral inferior lateral parietal cortex (ILP), but predominantly in the left ILP. This finding indicated that the ILP was directly associated with retrieval success and its lateralization was consistently left-sided irrespective of the type of stimulus.