Mechanical stability of the cementless acetabular component with three spikes

We studied the stability of our cementless acetabular component (socket) with 3 spikes in 65 joints of 65 patients who were followed for over 5 years. In 1 case, there was osteolysis around the femoral component (stem) but not around the socket. The movement of the socket and the radiolucent line was observed in 11 cases of osteoarthritis with acetabular hypoplasia (a mean of 43 degrees of the sharp angle) and 3 cases with rapidly destructive coxarthrosis. We could obtain favorable stability in 50 patients, including 38 with osteoarthritis (a mean of 41 degrees of the sharp angle), 8 with aseptic necrosis, 2 with rapidly destructive coxarthrosis, and 2 with rheumatoid arthritis. Our socket is very effective in preventing osteolysis and is expected to provide more stable mechanical stability by arranging an insertion angle (35 degrees of the optimal open angle and 10 degrees of the anteversion angle) and a full bone graft in osteoarthritic patients.

A comparative study of embedded nerve tissue in six NF2-associated schwannomas and 17 nonassociated NF2 schwannomas

BACKGROUND

Neurofibromatosis-2 (NF2) is an autosomal dominant disorder in which patients typically show bilateral acoustic tumors, and they are usually diagnosed histopathologically as schwannomas. The nerve of origin of a schwannoma is often demonstrated on the periphery along the capsule but not penetrating the substance of the tumor. However, there is a possibility that NF2 schwannomas and solitary schwannomas differ from participation in nerve components.

METHODS

In this study, the authors noted the relationship between the tumor and the original nerves. To detect whether there were embedded nerves in the tumor, immunohistologic staining using neurofilament and myelin basic protein antibodies was performed on 6 NF2 schwannomas and 17 non-NF2 schwannomas.

RESULTS

Four of five NF2 schwannomas had embedded nerves and one of four, which was considered to be the early stage of the tumor occurrence, remarkably embedded original nerves. On the other hand, embedded nerves were not seen in non-NF2 schwannomas.

CONCLUSIONS

The authors concluded that the NF2 schwannomas tend have original nerves embedded in the tumor substance, which may be based on the difference of the motility of tumor cells, and the authors believe that it is difficult to remove NF2 schwannomas while preserving the original nerve.

Multiple hepatoblastomas associated with trisomy 18 in a 3-year-old girl

A very rare case of full trisomy 18 associated with multiple hepatoblastomas is reported. The patient also had ventricular septal defect and patent ductus arteriosus, which were repaired at 6 months of age. After the cardiac surgery, she was noted to have an abdominal mass and an elevated serum alpha-fetoprotein level. A partial hepatic lobectomy was performed at 7 months of age, and the resected tumor was diagnosed as a fetal-type hepatoblastoma. At 2 years and 4 months of age, a chest radiography disclosed an elevated left diaphragm, and abdominal ultrasonography demonstrated a tumor in the left hepatic lobe. The resected tumor was also diagnosed as a fetal-type hepatoblastoma. Chromosomal analysis demonstrated that the karyotypes of peripheral blood and hepatic tumor cell obtained on two occasions were both 47,XX, +18. She has no evidence of recurrence at 3 years of age without specific therapy.

Effects of glycemic control on plasma 3-deoxyglucosone levels in NIDDM patients

OBJECTIVE

To clarify the effects of glycemic control on the level of 3-deoxyglucosone (3-DG), a reactive dicarbonyl compound, in plasma from diabetic patients.

RESEARCH DESIGN AND METHODS

Fasting plasma samples were collected from 15 healthy volunteers and 27 patients with NIDDM. Samples were collected from six poorly controlled patients before and after improved glycemic control for at least 2 months. Plasma 3-DG was determined by high-performance liquid chromatography (HPLC) as a 2,3-diaminonaphthalene derivative. We observed the relationship of 3-DG levels with plasma glucose or HbA1c levels and examined changes in 3-DG levels after glycemic control in the six patients.

RESULTS

Plasma 3-DG was significantly more increased in diabetic patients than in nondiabetic control subjects (31.8 +/- 11.3 vs. 12.8 +/- 5.2 ng/ml, means +/- SD, P < 0.001), but there was an approximately threefold difference in 3-DG levels among diabetic patients. 3-DG levels were well correlated with plasma glucose (r = 0.56, P < 0.005) and HbA1c levels (r = 0.74, P < 0.001) in diabetic patients. The improvement of hyperglycemia in six patients resulted in a significant decrease in 3-DG (35.2 +/- 13.2 vs. 21.3 +/- 3.4 ng/ml, P < 0.05).

CONCLUSIONS

The results indicate that the plasma glucose level is a predominant determinant of the plasma 3-DG level in diabetic patients and good glycemic control would be important to reduce this reactive metabolite.

Asp905Tyr polymorphism of protein phosphatase 1 G subunit gene in hypertension

A possible pathogenic polymorphism in the gene for the G subunit of the glycogen-associated regulatory form of protein phosphatase 1 (PP1 G subunit), causing an Asp-to-Tyr substitution at codon 905 (Asp905Tyr), has been reported to be associated with insulin resistance and hypersecretion of insulin in the white population. Since marked heterogeneity has been reported in the association of mutations of candidate genes with essential hypertension between Japanese and other ethnic groups, we investigated the association of Asp905Tyr with essential hypertension in Japanese subjects. The frequency of the Tyr allele in Japanese control subjects (0.70) was much higher than that in the Danish population (0.10, P<1x10(-8)), indicating that the Tyr allele, previously reported as a rare variant in white subjects, is a common allele in our population. The genotype distribution in Japanese hypertensive patients (n=109; Asp/Asp=0.09, Asp/Tyr=0.39, Tyr/Tyr=0.52) was not significantly different (chi2=0.7, df=2, P>.6) from that in normotensive control subjects (n=148; Asp/Asp=0.12, Asp/Tyr=0.36, Tyr/Tyr=0.52). Among subjects with different PP1 G subunit genotypes, there was no difference in blood pressure, serum cholesterol, plasma glucose and insulin levels, and glucose disposal rate estimated by the euglycemic hyperinsulinemic clamp test. These data indicate that the Asp905Tyr polymorphism of the PP1 G subunit is not associated with essential hypertension, nor with insulin resistance and/or hyperinsulinemia in Japanese patients with essential hypertension, suggesting that the polymorphism plays little if any role in susceptibility to insulin resistance or hypertension.

[Insulin, as a regulating factor of blood pressure]

In patients with hypertension, insulin resistance and hyperinsulinemia are more prevalent than in normal individuals. Furthermore, the prevalence of hypertension in diabetic patients is higher than in nondiabetic individuals. Insulin resistance has been implicated in the common mechanisms underlying diabetes, hypertension, hyperlipidemia and obesity. A number of mechanisms have been proposed to account for the elevation of BP secondary to hyperinsulinemia, such as 1) increased tubular reabsorption of sodium ions, 2) increased intracellular sodium and calcium ions, 3) increased sympathetic nervous activity, and 4) proliferation of vascular smooth muscle cells. Moreover, hypertension was reported to be a possible cause of insulin resistance. The detailed mechanism of insulin leading hypertension are still under investigation.

Display technique using time-dependent scatter diagrams for the study of changing relative timings of three spike trains: evaluation of functional connectivity in a local area of the nervous system

The relative timings of impulses caused by two neurons can be studied using cross-correlation techniques or the related techniques of the joint peristimulus-time histogram and the time-dependent correlation function. Analysis of the relative timings of several related neurons is important to the study of the dynamics, since we consider functional connectivity to be partially related to the dynamics. Functional connectivity changes of short duration reflect physiological functions rather than changes of synaptic connections. The relative timings of impulses are considered to reflect functional connectivity. Using the joint impulse configuration scatter diagram (JICSD) proposed by Perkel, a time-dependent scatter diagram (TDSD) is calculated to analyze the change of functional connectivity. The JICSD displays the long-time average of relative timings of impulses or the functional connectivity of three interconnected neurons. We generated JICSDs for short durations and we subsequently generated TDSDs by arranging JICSDs in chronological order. The change of a "snowflake pattern" of each JICSD was interpreted in terms of change of the functional connectivity. We propose a method for analyzing the changing functional connectivity among three neurons.

[Life-threatening ventricular tachyarrhythmia after CABG in a patient with poor LV function--an experience with the implantable cardioverter defibrillator]

A 52-year-old man with reduced left ventricular function (ejection fraction 0.27) due to myocardial infarction, underwent coronary artery bypass grafting (CABG; LITA-LAD, free RITA-4PD) for angina pectoris. He had suffered from recurrent sustained ventricular tachycardia (VT) since 5 hours after CABG. This arrhythmia was resistant to various antiarrhythmic agents such as Lidocaine, Mexiletine, Disopyramide, Procainamide and Propafenone. He required mechanical circulatory supports (intra-aortic balloon pumping and percutaneous cardiopulmonary support) for the maintenance of hemodynamics during repeated VT that required cardioversions of a total of 441 times during 18 days. Following the administration of Amiodarone, the VT was successfully suppressed. However, he had repeated episodes of VT on exercise, thus, he underwent insertion of the implantable cardioverter-defibrillator at the 98 post-operative day, and he was successfully discharged at the 134 post-operative day after CABG. The instrument was verified to be normal in function after the VT induction test.

Effect of an aldose reductase inhibitor on abnormalities of electroretinogram and vascular factors in diabetic rats

The effect of an aldose reductase inhibitor, [5-(3-thienyl) tetrazol-1-yl] acetic acid (TAT), on the electroretinogram was determined in rats with streptozotocin-induced diabetes. Laboratory chow containing 0.05% TAT was given to rats for 2 months, while other diabetic rats were untreated. Groups of TAT-treated and untreated normal rats were also studied. Treatment with TAT produced significant improvement of the electroretinogram. TAT shortened the peak latencies of the b-wave oscillatory potentials, which were significantly prolonged in untreated diabetic rats (P < 0.0001 vs. untreated normal rats). This was accompanied by a significant decrease in the retinal sorbitol and fructose concentrations (by 46.5% and 25.7%, respectively). TAT treatment of diabetic rats also markedly reduced ADP-induced platelet aggregation and significantly increased the red blood cell 2,3-diphosphoglycerate level, accompanied by a marked reduction in sorbitol and fructose concentrations of platelet and red blood cells. There were significant correlations between the summed b-wave peak latencies and platelet aggregation or the 2,3-diphosphoglycerate level in diabetic rats. These findings suggest that an aldose reductase inhibitor, TAT, has therapeutic value for diabetic retinopathy.

Pituitary stalk meningioma: case report

We report a 45-year-old woman with a meningioma which was in contact with only the pituitary stalk on MRI. As the pituitary stalk has no dura mater, we suggest this tumour may have originated from the arachnoid membrane of the pituitary stalk. Though some reports have shown that meningiomas can arise from sites lacking a dural component, this is the first report of a meningioma originating from the pituitary stalk.

Insulin gene region contributes to genetic susceptibility to, but may not to low incidence of, insulin-dependent diabetes mellitus in Japanese

In the Caucasian population, it has been demonstrated that the insulin gene (INS) region contains the insulin-dependent diabetes mellitus locus (IDDM2). In the Japanese population, however, there has been no report demonstrating the contribution of IDDM2 to the pathogenesis of IDDM. We conducted an association study of IDDM in a large number of Japanese subjects with multiple polymorphisms in INS region. We found a significant association of the INS region with IDDM. Alleles positively associated with IDDM in INS region were the same as those positively-associated with IDDM in Caucasian population, although positively-associated alleles are very common (allele frequencies > 0.9) in the Japanese general population. These data suggest that IDDM2 is involved in the genetic susceptibility to IDDM in Japanese. The high frequencies of disease-associated alleles in the general population suggest that IDDM2 locus is not responsible for the low incidence of IDDM in Japanese.

Possible implication of leukocytes in secondary pathological changes after spinal cord injury

We reviewed 95 consecutive patients with cervical spinal cord injury admitted within 2 days of injury and treated nonoperatively, to elucidate the relationship between neurological deterioration and the white blood cell count in the first 4 days after injury. The count for 14 patients who had neurological deterioration was 13.2 +/- 3.2 x 10(9)/l, and that for 81 patients who had no deterioration was 11.0 +/- 3.1 x 10(9)/l. None of 19 patients whose highest white blood cell count was less than 9 x 10(9)l deteriorated, while 14 of 76 patients whose count was 9 x 10(9)/l or more deteriorated. These results suggest that the white blood cell is important in the secondary pathological changes after mechanical injury to the spinal cord.

The significance of tumor necrosis factor (TNF) levels for rejection of joint allograft

This paper describes the efficacy of utilizing Tumor Necrosis Factor-alpha (TNF) as a detectable parameter of acute rejection after bone allografts. The authors used a bone-joint allograft model, transferring vascularized allograft knee joints across a major histocompatibility barrier, using three groups of rats divided into controls, non-immunosuppressed, and immunosuppressed with cyclosporine. The paper supplies preliminary information suggesting that TNF may be a marker for early bone-joint allograft rejection.

Expression of neurofibromatosis 2 protein in human brain tumors: an immunohistochemical study

The neurofibromatosis 2 (NF2) gene-encoded protein, named merlin, may function as a molecular linkage connecting cytoskeleton and plasma membrane. Merlin is thought to play a crucial role as a tumor suppressor not only in hereditary NF2-related tumors, but also in sporadic tumors such as schwannomas, meningiomas and gliomas. Using a merlin-expression vector system, we raised specific antiserum against merlin. We observed the intracellular distribution of merlin in cultured glioma cells, and further investigated merlin expression in 116 human brain tumors. Immunofluorescence microscopy revealed that merlin was localized beneath the cell membrane and concentrated at cell-to-cell adhesion sites, where actin filaments are densely associated with plasma membrane. By immunohistochemistry, none of the schwannomas from either NF2 patients or sporadic cases showed any immunoreactivity, while normal Schwann cells of cranial nerves were immunopositive. In meningiomas, merlin expression was frequently seen in the meningothelial subtype (8/10, 80%), but no expression could be detected in either the fibrous or the transitional variant. Most normal astrocytes were negative; however, reactive astrocytes often expressed merlin. Glioblastomas and anaplastic astrocytomas were found to be strongly positive, and focal positive staining was observed in fibrillary and pilocytic astrocytomas. Thus, the loss of merlin appears to be integral to schwannoma formation and the differential pathogenesis of meningioma subtypes. However, merlin alterations do not appear to play a critical role in either the tumorigenesis or malignant transformation of neoplastic astrocytes.

Increased alanine uptake and lipid synthesis from alanine in isolated hepatocytes of Wistar-Kyoto fatty rats: an inhibitory effect of biguanides

To examine the pathophysiological characteristics of non-insulin-dependent diabetes mellitus, alanine metabolism in isolated hepatocytes of male Wistar-Kyoto (WKY) fatty rats (genetically obese and hyperglycemic) and their lean littermates was investigated. The effects of glucagon and the biguanides, metformin and buformin, on alanine metabolism were also studied by measuring alanine uptake and lipid synthesis from alanine. WKY fatty rats showed higher plasma insulin and lipid concentrations than lean rats at 5 as well as at 12 weeks of age. Alanine uptake into hepatocytes was increased in fatty rats only at 12 weeks of age compared with lean rats. Lipid synthesis from alanine in hepatocytes was increased in fatty rats at 5 and 12 weeks of age compared with lean rats. Glucagon increased alanine uptake into hepatocytes but did not affect lipid synthesis from alanine in both fatty and lean rats. Low concentrations (0.1 mM) of biguanides decreased lipid synthesis from alanine only in fatty rats without inhibiting alanine uptake into hepatocytes. These observations suggest that lipid synthesis from alanine in hepatocytes of WKY fatty rats is accelerated prior to the onset of diabetes mellitus, which might be associated with the development of diabetes, and that an inhibitory effect on increased lipid synthesis is one of the pharmacodynamic actions of biguanides.