Pancreatic xanthomatous neuropathy associated with hyperlipidemia: a cause of abdominal pain mimicking chronic pancreatitis

"Hyperlipidemic crisis" is a term used to describe episodic abdominal pain in patients with hyperlipidemia. The morphologic correlates of this phenomenon have not been investigated and the etiology of the disorder is uncertain. We report a unique histologic finding in the pancreas of a 34-year-old woman with a 17-year history of episodic abdominal pain, sometimes accompanied by hyperamylasemia. At the age of 18 years, grossly elevated cholesterol and triglyceride levels were documented and type V hyperlipidemia was diagnosed. At the age of 34 years, subtotal pancreatectomy was performed for intractable abdominal pain. Histologic examination identified an increased number of enlarged pancreatic nerves that were infiltrated by foamy macrophages and encircled by fibrous tissue; endoneurial infiltration with macrophages occasionally split nerves into individual fascicles. Otherwise, the pancreas had only minimal fibrosis, nesidioblastosis, mucinous metaplasia of some pancreatic ducts, and scattered small collections of chronic inflammatory cells, subtle features suggesting very mild chronic pancreatitis. We propose that this novel xanthomatous neuropathy mimicked pancreatitis and was one of the underlying pathophysiologic mechanisms of abdominal pain in this patient. Further studies are necessary to document the prevalence of this new entity in patients with hyperlipidemia and to correlate its occurrence with "hyperlipidemic crisis" in those individuals.     

Acute kidney failure in hypothermia

Two cases with acute renal failure after prolonged hypothermia are presented. Both patients were found in come, became rapidly uremic and required hemodilaysis treatment. Although the laboratory findings were typical of severe muscle damage, e.g. elevated levels of serum creatinine phosphokinase, serum lactic dehydrogenase and serum aldolase activities, visible "crush-injuries" were not found. Acute renal failure was characterized by extreme catabolism and severe metabolic acidosis. After 4 and 10 hemodialyses respectively, the patients became polyuric and finally were discharges with normal renal and muscle function. Hypotension with diminished renal perfusion and nontraumatic rhabdomyolysis due to prolonged hypothermia are regarded as the dominant pathogenetic factors in the acute renal failure.     

Subjective time experience in an intergenerational sample

The roles chronological age and gender play in subjective time experience were explored in a sample of 294 adult men and women. Subjective time experience (STE: the difference between subjective age and chronological age) was found to vary widely among individuals, with some being "accurate" (SA = CA), and others either "retarded" (SA less than CA) or "advanced" (SA greater than CA). Males were more retarded in STE than females at every point in the lifespan, and patterns of age differences in adulthood differed for the two sexes as well. The results suggest that chronological age may play a key role in transitions in STE, and that chronological age is more significant in the STE of women than in the STE of men.     

A distortion measure for blocking artifacts in images based onhuman visual sensitivity

A visual model that gives a distortion measure for blocking artifacts in images is presented. Given the original and reproduced image as inputs, the model output is a numerical value that quantifies the visibility of blocking error in the reproduced image. The model is derived based on the human visual sensitivity to horizontal and vertical edge artifacts that result from blocking. Psychovisual experiments have been carried out to measure the visual sensitivity to these artifacts. In the experiments, typical edge artifacts are shown to subjects and the sensitivity to them is measured with the variation of background luminance, background activity, edge length, and edge amplitude. Synthetic test patterns are used as background images in the experiments. The sensitivity measures thus obtained are used to estimate the model parameters. The final model is tested on real images, and the results show that the error visibility predicted by the model correlates well with the subjective ranking.     

Precessional slip in an angular contact ball bearing

A previously reported ball precessional motion in an angular contact bearing is analyzed. Explicit forms for ball-race slip are given, both with and without precession. Slip and entrainment velocity at ball-ball contacts in a retainerless bearing are also given, also with and without precession. It is shown that the observed precession does not change the hertzian slip fields very much at either contact, compared with those produced by pure spin.     

The role of mineralocorticoid receptors in hypothalamic-pituitary-adrenal axis regulation in humans

In rodents, two types of glucocorticoid receptors, the mineralocorticoid (MR; type I) and the glucocorticoid (type II) receptors, have been demonstrated to play a role in hypothalamic-pituitary-adrenal (HPA) axis regulation. Because MR shows a very high affinity for cortisol, it has been suggested that MR plays an important role in restraint of CRH and ACTH secretion during the nadir of the circadian rhythm. Although a number of studies have established the importance of MR in rodents, the functional role of MR in humans has not been determined. These studies evaluated whether spironolactone, an MR antagonist, had a detectable effect on HPA axis regulation in humans, and whether the effect was greatest during the evening, when plasma cortisol concentrations are in the MR range. Compared to the placebo day, after a single dose of spironolactone at either 0800 or 1600 h, there is a significant increase in plasma cortisol, which is preceded by a rise in ACTH and beta-endorphin. A significant effect of spironolactone on cortisol secretion was demonstrated with no differences between the morning and evening. Because the effect of spironolactone on cortisol was short lived, a second experiment was conducted using two doses of spironolactone, again sampling in the morning and evening. After two doses of spironolactone, plasma cortisol levels showed a significant and sustained spironolactone-induced elevation for the entire sampling period. However, neither plasma beta-endorphin nor ACTH was increased compared to levels on the placebo day. These data suggest that MR appear to play a clear role in HPA axis regulation during the time of the circadian peak as well as the trough. Furthermore, MR blockade may affect the sensitivity of the adrenal to ACTH.     

Crystal growth in dental enamel: the role of amelogenins and albumin

Amelogenin-mineral interactions were investigated using an in vitro binding approach. Rat incisor enamel matrix proteins (mainly amelogenins) were dissolved in synthetic enamel fluid and allowed to equilibrate with deproteinised developing enamel crystals. The results showed that amlogenin proteins of 21, 23, 24, 26 and 27-kDa (corresponding to nascent and partially degraded amelogenins) were associated with the crystals whilst the lower Mr amelogenins (< 21 KDa) remained free in the synthetic enamel fluid. These data suggest the nascent and partially degraded amelogenins may interact with developing enamel crystals and could influence their growth. Albumin-mineral interactions were investigated by extracting developing rat incisor enamel with synthetic enamel fluid. Insoluble material (including the enamel crystals) was then further extracted with 0.1 M phosphate buffer (pH 7.4) to desorb any mineral bound proteins. Western blotting using anti-albumin antibodies showed that almost all of the albumin from the secretory stage enamel and a significant proportion of the albumin present in early transition stage was extractable in the synthetic enamel fluid. However, synthetic enamel fluid did not extract albumin from late transition or maturation stage tissue, which could only be removed following further extraction with phosphate buffer. Albumin degradation was apparent during the transition and maturation stages, where it is degraded and ultimately removed. This binding pattern may be related to amelogenin degradation and removal during the transition stage, permitting albumin access to the previously obscured crystal surfaces. That the secretory stage matrix appears to "protect" secretory stage crystals from albumin may be an important consideration in the aetiology of enamel hypoplasias (i.e. incomplete crystal growth) and when using dissociative extraction procedures for the identification of mineral bound proteins.     

Molecular analysis of T-cell receptor repertoire in bone marrow transplant recipients: evidence for oligoclonal T-cell expansion in graft-versus-host disease lesions

We have analyzed the T-cell receptor (TCR) V beta repertoire using polymerase chain reaction (PCR) in a cohort of eight patients receiving allogeneic bone marrow transplantation (BMT) from related and unrelated donors at the City of Hope. Results of PCR studies from graft-versus-host disease (GVHD) skin lesions show a bias in the usage of TCR V beta families, whereas examination of peripheral blood (PB) withdrawn at the same time did not reveal a similar phenomenon. In one such family, TCR V beta 2 is predominantly expressed in 7 of 7 biopsy specimens examined. V beta 2 TCR expression from these patients was analyzed more extensively using a combination of individual TCR gene cloning, followed by sequence analysis. We found evidence of oligoclonal expansion of single V beta 2-bearing TCRs in GVHD lesions, and in the PB of some patients after diagnosis of GVHD. In contrast, GVHD-negative biopsy samples showed no evidence for clonotypic TCR amplification. Sequence-specific TCR CDR3 region probes were derived from analysis of the predominant expressed TCR in GVHD lesions, and used to probe Southern blots of amplified V beta 2 TCR mRNA from PB and tissue from BMT recipients and their respective donors. In most cases the probes are highly specific in detecting TCR expression from GVHD lesions alone, although in several instances expression could be detected in PB after GVHD diagnosis. These data provide supporting evidence for the hypothesis that acute GVHD is associated with expansion of T-cell clones expressing antigen-specific TCRs that may contribute to the disease pathology.     

Characterization of DNA sequences encoding a novel isoform of the 55 kDa B regulatory subunit of the type 2A protein serine/threonine phosphatase of Arabidopsis thaliana

We have identified a novel gene (AtB beta) encoding a previously uncharacterized isoform of the B regulatory subunit of the type 2A serine/threonine protein phosphatase (PP2A) of Arabidopsis, and show that mRNA derived from the AtB beta gene accumulates in all Arabidopsis organs. In addition, we examined the expression of the three genes encoding the A regulatory subunit of Arabidopsis PP2A and show these genes are expressed in all organs as well. Taken together, our results suggest a myriad of PP2A subunit combinations, possibly with distinct substrate specificities, may occur within each Arabidopsis cell.