Imaging of a vortex lattice transition in YNi2B2C by scanning tunneling spectroscopy

The vortex lattices in YNi2B2C under the magnetic fields H up to 3 T applied along both the a and the c axes have been studied by scanning tunneling spectroscopy at 4.2 K. The vortex lattice transition has been found to occur in different manners for H parallela and H parallelc; in H parallela a slightly distorted hexagonal vortex lattice has been found to transform to a nearly square one above 1.0 T with increasing H, while in H parallelc the transition occurs at a much lower field around 0.1 T. The unconventional steep increase of the quasiparticle density of states outside the vortex core has also been found well below H(c2).

Functional changes in aging polymorphonuclear leukocytes.

BACKGROUND: Previous studies from our laboratory have shown that the expression of L-selectin on polymorphonuclear neutrophils (PMN) decreases as the cell ages in the circulation and that these older PMN have more fragmented DNA and show morphological features of apoptosis. METHODS AND RESULTS: The present study was designed to compare the functional capabilities of PMN expressing low levels of L-selectin (L-selectin[low]) and the total population of PMN they were isolated from (L-selectin[mixed]). The results show no difference of the baseline filamentous actin (F-actin) content between PMN expressing low and high levels of L-selectin. However, the ability of L-selectin(low) PMN to assemble F-actin was impaired after stimulation by n-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) (1 nmol/L fMLP: P<.02, 10 nmol/L fMLP: P<.01). The ability of L-selectin(low) PMN to change shape when stimulated (10 nmol/L fMLP) was also decreased (P<.05). Filtration studies showed no difference in baseline deformability between L-selectin(low) and L-selectin(mixed) leukocytes, but the L-selectin(low) cells showed a decreased ability to stiffen after fMLP stimulation (P<.05). L-selectin(low) cells demonstrated a decreased ability to migrate toward a chemoattractant (1, 3, and 10 nmol/L fMLP) (P<.004) but have an enhanced ability to upregulate CD18 (P<.00002) and produce hydrogen peroxide (P<.00004). CONCLUSIONS: We conclude that PMN undergo substantial functional changes as they age in the circulation.

Apoptosis in circulating PMN: increased susceptibility in L-selectin-deficient PMN.

Previous work from our laboratory has shown that polymorphonuclear leukocytes (PMN) lose L-selectin as they age in the circulation. The present study was designed to examine the relationship between PMN age and susceptibility to apoptosis in the circulation using L-selectin as a marker of PMN age in rabbits. L-selectin-deficient leukocytes were separated from a mixed population of PMN in leukocyte-rich plasma using magnetic beads. Apoptosis was measured both with both morphological criteria and by determining the level of DNA fragmentation. The L-selectin-deficient cells separated in vitro showed morphological features of apoptosis (P < 0.01) and had higher levels of DNA fragmentation (P < 0.01) than the mixed population of PMN from which they were obtained. To determine if aging had a similar effect in vivo, PMN were labeled in the bone marrow with 5'-bromo-2'-deoxyuridine (BrdU) and L-selectin levels (immunocytochemistry) and DNA fragmentation (sandwich enzyme-linked immunosorbent assay) were measured in BrdU-labeled PMN in peripheral blood. The results showed that the peak release of BrdU-labeled PMN from the bone marrow into peripheral blood was associated with high levels of L-selectin expression, and these PMN had the lowest levels of DNA fragmentation. These results confirm that the level of L-selectin expression can be used as a marker of cell age and extend this observation by showing that aging in the circulation is associated with an increased susceptibility to apoptosis.

[A case of surgically treated left atrial myxoma early after cerebral embolism].

A 48-year-old female had been visiting the outpatient clinic for treatment of polyarthritis before she was admitted to the hospital due to consciousness disorder and right hemiplegia. Brain computed tomography revealed a small infarction in the left cerebrum. Echocardiography revealed a mass in the left atrium. She was diagnosed cerebral embolism caused by left atrial myxoma. Extirpation of left atrial myxoma was performed 16 days after the onset of cerebral infarction. The postoperative course was good. Preoperative constitutional signs such as multiple arthralgia and abnormal sensation disappeared on the 2nd postoperative day. Open heart surgery performed early after the onset of cerebral embolism is generally considered contraindicated due to problems of hemorrhagic infarction or brain edema. Because relapse of embolism may deteriorate the condition, losing the chance of surgery, extirpation of left atrial myxoma early after the onset of cerebral infarction is advisable in cases of small infarction.

Long-term effects of simvastatin in hypercholesterolemic patients with NIDDM and additional atherosclerotic risk factors. Hyogo Simvastatin Study Group.

Effects of 12 months of simvastatin treatment were examined in 48 NIDDM patients with total serum cholesterol levels exceeding 220 mg/dl and were compared with those in 35 nondiabetic patients with hypercholesterolemia. In the diabetic group, 5-10 mg of simvastatin given once daily at bedtime significantly lowered total cholesterol (21%). LDL cholesterol (28%), apoB (15%) and triglycerides (8%) levels. These changes were identical to those in the nondiabetic group, except for triglycerides which did not change significantly. HDL cholesterol increased significantly in the nondiabetic group but not in the diabetic group. The reductions in LDL cholesterol and apoB in hypercholesterolemic patients with NIDDM were not influenced by gender, age, glycemic control, the presence or absence of systemic hypertension, obesity and overt proteinuria. In addition, the decrease in LDL cholesterol was not affected by the number of risk factors per patient. Simvastatin did not significantly alter hemoglobin A1c or fasting plasma glucose and was well tolerated in both groups. Simvastatin produced beneficial effects on serum lipids and apolipoproteins and neutral effects on glycemic control in hypercholesterolemic patients with NIDDM, whether or not they had an additional atherosclerotic risk factor.

Evaluation of nested polymerase chain reaction for detecting mycobacterial DNA in pleural fluid.

A protocol based on the polymerase chain reaction (PCR) is the most sensitive method for detecting mycobacteria in clinical samples. However, few studies have assessed the usefulness of this method in the diagnosis of tuberculous effusion. We developed a highly sensitive and specific nested PCR method, that amplifies the bovine tuberculous MPB70 gene and the mycobacterial 16S rRNA gene for use in detecting Mycobacterium tuberculosis (M. tuberculosis) and mycobacteria, respectively, in clinical samples. We determined the sensitivity of this method for detecting mycobacteria in samples containing known amounts of mycobacterial DNA and in DNA extracted from pleural effusions obtained from 10 patients with pulmonary tuberculosis in whom standard microbiological techniques had detected mycobacteria in sputum but not in pleural effusion. The nested PCR method for the bovine tuberculous MPB70 gene and the mycobacterial 16S RNA gene was able to detect M. tuberculosis and mycobacterial genomes only if there were at least 2 copies per sample. Positive results for M. tuberculosis and the mycobacterial genomes were obtained by nested PCR in 2 of 10 and in 3 of 10 samples of pleural fluid, respectively but no mycobacteria were detected in malignant effusions obtained from 9 patients with lung cancer. The nested PCR method represents a rapid means for detecting mycobacteria in some pleural effusions previously found to be negative by culture. We speculate that the reaction of the host against mycobacteria is more important than the mycobacteria themselves in the pathogenesis of pleural effusion in which mycobacteria are not detected.

Scanning electronmicroscopic morphometry of emphysema in humans.

We quantitated the holes in alveolar walls in 11 nonemphysematous lungs and in 11 lungs with mild emphysema, all of which were removed at surgery. We found that in the nonemphysematous lungs, 94.1% of the holes were smaller than 10 microns in diameter and only 0.2% were larger than 20 microns. In the lung parenchyma distant from emphysema, both the maximum diameter of the holes and the diameter of alveoli increased. In the parenchyma between emphysema, the areas of alveolar walls represented by holes also increased, as did the average hole area and number of holes per alveolus. We found that alveolar holes in the regions between emphysema correlated better with pulmonary function tests than did those in regions distant from emphysema. The maximum diameter of holes and the number of holes per alveolus correlated with functional residual capacity, residual volume, closing capacity expressed as a proportion of total lung capacity (CC/TLC), and static recoil pressure of the lung at TLC. Emphysema correlated with CC/TLC and with the transpulmonary pressure at 90% TLC. Bronchiolar lesions were not related to pulmonary function tests. Our data provide support for the hypothesis that the tissue surrounding emphysematous lesions contributes to loss of recoil.

Acute pneumonitis presumed to be silicone embolism.

A 39-year-old housewife who underwent intramammary injections of a proprietary silicone fluid mixture showed clinical and novel transbronchial lung biopsy (TBLB) findings. She presented with complaints of progressive dyspnea, dry cough, and pleuritic chest pain 2 days after the last silicone injections. The chest X-ray and CT scan showed diffuse interstitial infiltrates. TBLB demonstrated translucent, presumably silicone globules embolized within the pulmonary capillaries. The documentation of intramammary injections, the clinical and radiographic features of acute pneumonitis, and the histopathologic evidence by TBLB, may support the causal relationship between illicit injections and the silicone embolism. We discuss the pathogenesis and urge that this potentially toxic source of pulmonary embolism be removed.

[A case of adenocarcinoma presenting as a cavitary lesion with niveau formation].

Primary pulmonary adenocarcinoma rarely shows cavitation with a fluid level on chest roentgenograms. Herein we describe such a case misdiagnosed as pulmonary tuberculosis. The patient was a 63-year-old, female who had never smoked. Chest roentgenograms revealed a cavitary lesion in the left lower lobe, possessing a prominent fluid level. Fiberoptic bronchoscopic aspirate was positive for acid-fast bacilli on stains. Since there was no improvement with antituberculous chemotherapy, a left lower lobectomy was performed. The present case is of interest in the light of cavity formation in pulmonary carcinoma. The diagnosis and roentgenographic features are discussed.

Intracaval and intracardiac extension of malignant thymoma.

A case of malignant thymoma presenting as the superior vena cava syndrome is reported. A 56-year old male was admitted with superior vena cava syndrome. CT and NMR-CT scan showed a solid homogenous superior mediastinal mass; which filled the lumen of the superior vena cava and the right atrium. A biopsy of the right atrial mass showed myxoma, and operation was performed. Histopathologically the tumor was diagnosed as thymoma. Intracaval and intracardiac extension of a thymoma is very rare.

Effect of probucol on recovery from streptozotocin diabetes in rats.

The present study was conducted to see the effect of probucol on streptozotocin diabetes in rats. After 2 weeks of a 1% probucol diet, 35 or 50 mg/kg of streptozotocin were intravenously injected into male Wistar rats. All the rats became diabetic 2 days after treatment. Thereafter, in order to see the effect of probucol on spontaneous recovery from streptozotocin diabetes, 25 mg/kg of streptozotocin was injected into rats after two weeks of probucol diet and the diet was continued for additional two weeks. All the rats with a standard diet (group CS, n = 13) and 12 of 13 rats with probucol diet (group PS) became diabetic 2 days after streptozotocin injection. One rate from group PS did not develop diabetes. Two weeks after injection, only 4 of 13 rats in groups CS showed recovery, while 11 of 12 rats in group PS showed recovery from streptozotocin diabetes (p less than 0.05). The average blood glucose levels in group PS were significantly lower than group CS (10.5 +/- 4.6 vs 18.5 +/- 0.6 mM, p less than 0.05). In addition, the pancreatic insulin content of group PS was 8 times greater than that of group CS (0.75 +/- 0.24 vs 0.09 +/- 0.03 mmol/pancreas, p less than 0.01). Thus, the in vivo diabetogenic action of streptozotocin could not be reduced by pretreatment with probucol. However, recovery from streptozotocin diabetes was induced by subsequent treatment with probucol. The precise mechanisms for this phenomenon were not known; but the present findings suggest the protective effect of probucol on beta-cell damage induced by small dose of streptozotocin.

Effect of mild diabetes and dietary fructose on very-low-density lipoprotein triglyceride turnover in rats.

Very-low-density lipoprotein (VLDL) triglyceride turnover was examined in mildly streptozotocin (25 mg/kg)-diabetic rats, using Triton WR1339. Diabetic rats fed standard rat chow showed mild hyperglycemia and suppressed levels of plasma insulin. Their triglyceride secretion was significantly suppressed despite an elevated level of plasma free fatty acids. However, the plasma triglyceride level of these diabetic rats was significantly elevated compared with nondiabetic controls. This suggested that the removal of triglyceride from the circulation, as well as its entry into the circulation, was impaired in mildly insulin-deficient rats. Glucose or fructose supplementation (10% in drinking water for 14 days) significantly increased the triglyceride secretion rate of diabetic rats. Especially, fructose supplementation increased plasma insulin to normal levels, but resulted in markedly elevated plasma triglyceride levels (three times higher than glucose-supplemented or chow-fed diabetic rats) despite similar triglyceride secretion rates between the two types of sugar-supplemented diabetic rat groups. This suggested an impairment of triglyceride removal by dietary fructose. The result obtained from chow-fed diabetic rats indicates that mild but significant insulin deficiency resulted in mild hypertriglyceridemia, linked to impaired triglyceride removal rather than to an overproduction of VLDL-triglyceride, despite elevated levels of plasma free fatty acids. Furthermore, fructose feeding induced prominent hypertriglyceridemia not only by stimulating triglyceride secretion, but also by suppressing triglyceride removal from the circulation of mildly diabetic rats.

Effect of long-term insulin deficiency and insulin treatment on the composition of triglyceride-rich lipoproteins and triglyceride turnover in rats.

The effect of long-term (4 months) insulin deficiency on triglyceride turnover was examined using Triton WR1339 in rats. Triglyceride secretion rate was estimated in rats 2 weeks and 4 months after induction of diabetes with 40 mg/kg of streptozotocin. By the second week diabetic rats showed prominent hyperglycemia and the plasma insulin level was very low. In spite of a lower triglyceride secretion rate compared to non-diabetic control rats, diabetic rats showed normotriglyceridemia. Thus, the estimated fractional catabolic rate for plasma triglyceride was decreased in the diabetic rats of 2 weeks duration. By the fourth month diabetic rats still showed a suppressed triglyceride secretion rate but plasma triglyceride was markedly higher than in the non-diabetic control rats. Therefore, their estimated fractional catabolic rate for plasma triglyceride was severely suppressed. They also showed hyperglycemia and hypercholesterolemia. The triglyceride-rich lipoprotein particles obtained after Triton injection in long-term diabetic rats were significantly cholesterol-enriched and triglyceride-depleted compared to control rats. These changes were already present in 2-week diabetic rats but the magnitude was significantly smaller that those in long-term diabetic rats. All of these abnormalities (including triglyceride turnover and the particle composition) were almost normalized by 2 weeks of insulin treatment (6 units/day). Thus, it was concluded from the present data that duration of insulin deficiency is an important determinant of triglyceride removal rate from the circulation in rats. Further modification of lipid composition of triglyceride-rich lipoprotein particles by long-term insulin-deficiency could be one of the reasons for this removal defect.(ABSTRACT TRUNCATED AT 250 WORDS)

Atypical lipoma of the lung.

An unusual endobronchial lipoma characterised by pleomorphic, multinucleated giant cells admixed with mature adipose cells developed in a 52 year old woman, arising from the right middle lobe bronchus. Lobectomy was performed and the postoperative course was uneventful.

Effects of dietary glucose or fructose on the secretion rate and particle size of triglyceride-rich lipoproteins in Zucker fatty rats.

Effects of dietary carbohydrate on the secretion rate and particle size of triglyceride-rich lipoproteins were examined in Zucker fatty rats fed fructose and glucose and were compared with those of Zucker lean rats. Carbohydrates were supplied as 10% drinking solutions for 14 days. As compared with lean rats, Zucker fatty rats had hyperinsulinemia and hypertriglyceridemia associated with an increased rate of triglyceride secretion into the circulation. Feeding fructose and glucose to fatty rats produced an increase in plasma glucose levels, whereas plasma insulin concentrations did not show significant changes. Neither fructose nor glucose supplementation produced significant changes in the rate of triglyceride secretion. Despite this, plasma triglyceride concentrations in fructose-fed fatty rats were twice as high as those in glucose-fed rats or those receiving no supplementary carbohydrate. Particle diameters of lipoproteins of density between 0.96 and 1.006 were larger in fructose-fed fatty rats than in those receiving no sugar. The results suggest that feeding fructose, but not glucose, into fatty rats is associated with an impairment of triglyceride removal and a resultant increase in plasma triglyceride concentration, the latter of which is accompanied by an increase in triglyceride contents in each particle.

[The CT diagnosis of emphysema and correlation with pathologic findings].

It is difficult to diagnose clinically silent or mild emphysema. The efficacy of CT scans for the diagnosis of emphysema has attracted attention and comparisons have been made between CT images and the pathological grade of emphysema in resected lungs. With a view to determine to what extent high resolution CT images are accurate concerning the diagnosis of mild emphysema, we conducted an extensive comparative study on CT scores of emphysema, based on high resolution CT, the pathology score derived from the cut surface of the lung identical in its plane with that of the CT and destructive index (DI) which is said to be instrumental in representing the degree of deterioration of alveolar walls in the same regions of the lungs. In this study, 42 patients who underwent thoracotomy and their lung specimens including a solitary nodule of considerable size have been employed. The CT scores and pathology scores depend on the picture grading system developed by Thurlbeck and coworkers for the basis of counting. The findings were such that with 1 mm collimation, the CT scores ranged between 12 and 57 with a mean +/- SD of 22.1 +/- 9.6 (n = 35) while with 5 mm collimation, the CT scores ranged between 7 and 46 with a mean +/- SD of 16.5 +/- 8.3 (n = 33). The pathology scores stood at 10 to 57 with a mean +/- SD of 23.2 +/- 9.8 (n = 42).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of probucol on triglyceride turnover in streptozotocin-diabetic rats.

The long-term effect of probucol on triglyceride turnover was examined in streptozotocin (40 mg/kg) diabetic rats. Two diabetic groups were prepared: one group received a probucol-containing (1%) diet (probucol-treated diabetic) and the other standard diet (diabetic control). After 4 months of probucol diet, triglyceride turnover was estimated using Triton WR1339. In diabetic control rats, glucose, triglyceride and cholesterol concentrations in plasma and in the very low density lipoprotein (VLDL) fraction were markedly elevated and plasma insulin was suppressed compared to non-diabetic control rats. There was no significant difference in body weight, plasma glucose and insulin between the 2 diabetic groups. However, the probucol-treated diabetic group showed significantly suppressed levels of triglyceride and cholesterol in total plasma and in the VLDL fraction compared to each corresponding diabetic control value. On the other hand, there were no significant differences in triglyceride secretion rate between the 2 diabetic groups. Newly secreted VLDL particles after Triton injection from diabetic control rats were significantly cholesterol-enriched and triglyceride-depleted compared to those from non-diabetic control rats. However, the composition of those from probucol-treated diabetic rats was similar to that of non-diabetic control group. Prominent hypertriglyceridemia without increase in triglyceride secretion rate in diabetic control group indicates triglyceride removal defect in diabetic rats. Significant suppression of plasma triglyceride level without changes in the triglyceride secretion rate in the probucol-treated diabetic group suggests that probucol stimulated triglyceride removal in diabetic rats. Thus, probucol might normalize VLDL composition, thereby contributing to accelerated triglyceride removal from the circulation of streptozotocin diabetic rats without affecting glucose metabolism.

Hypoplasia of the internal carotid artery--report of an unusual case.

We present a rare case of unilateral internal carotid artery (ICA) hypoplasia associated with arterial anomalies in the circle of Willis. The ipsilateral middle cerebral artery was supplied via anomalous arteries from the posterior cerebral artery and the ICA. The ipsilateral common carotid artery also originated from the anomalous brachiocephalic trunk. The etiology of the hypoplastic ICA is uncertain, but the associated multiple vascular anomalies support the congenital origin.

Tension and instantaneous stiffness of single muscle fibers immersed in Ringer solution of decreased tonicity.

Isometric tension and instantaneous stiffness were measured in frog semitendinosus single muscle fibers in both isotonic and hypotonic Ringer solution. In 0.7 and 0.5 x normal Ringer tension increased 17 and 20%, respectively. There was no corresponding increase in the measured stiffness. The increase in tension in hypotonic Ringer could be reversed by the addition of an osmotic equivalent of sucrose to the bathing solution. These findings suggest that the potentiated tension observed in hypotonic Ringer is due to an increased tension per cross-bridge and not to an increase in the number of attached cross-bridges.