Production of cytokines by bone marrow cells obtained from patients with multiple myeloma

Previous work with continuously cultured multiple myeloma lines suggested that cytokine production by tumor cells may mediate some of the medical complications of this disease. To further investigate this issue, we assayed freshly obtained bone marrow (BM) cells from myeloma patients for the in vitro production of cytokines and the presence of cytokine RNA. Production of cytokine protein was assessed by bioassays with the aid of specific neutralizing anticytokine antibodies. These assays detected interleukin-1 (IL-1) and tumor necrosis factor (TNF) secretion by myeloma BM cells, which was significantly greater than secretion from similarly processed BM cells of control individuals. In contrast, lymphotoxin and interleukin-2 (IL-2) production could not be detected. The levels of IL-1 and TNF produced in vitro peaked at 24 hours of culture and correlated with stage and the presence (or absence) of extensive osteolytic bone disease. Northern blot analysis demonstrated the presence of IL-1 beta and TNF RNA in uncultured myeloma BM cells but no detectable IL-1 alpha or lymphotoxin RNA. In addition, the amount of cytokine RNA correlated with protein production, being significantly greater in patients' BM cells than in control marrow. These data suggest a role for IL-1 beta and/or TNF in the pathophysiology of multiple myeloma and argue against a role for lymphotoxin or IL-2.     

Seeking the just price: constructing relative value scales and fee schedules

Many conceptual issues underlie the current policy debate over how to reform the fee-for-service method of paying physicians, including the development of a relative value scale for physicians' services and the relationship between a relative value scale and a fee schedule. We consider the relationship between fees and costs and the criteria for judging whether a fee is appropriate or right and then propose a two-step process for constructing a relative value scale. A fee schedule based on a relative value scale is the most practical way to reform the current fee-for-service system and makes the most sense from both clinical and economic viewpoints.     

Proteoglycans of human rotator cuff tendons

Rotator cuff and biceps tendons that appeared grossly normal were procured from adult cadavers without a history of shoulder problems. These tendons were analyzed for the amount and type of glycosaminoglycan, type of proteoglycan, and histology. When compared with the distal/tensional region of biceps tendon, the glycosaminoglycan content of supraspinatus, infraspinatus, and subscapularis tendons was 2.5-fold higher and the glycosaminoglycan content of the proximal/compressed region of biceps tendon was 3-fold higher. The ratio of hyaluronic acid to chondroitin sulfate/dermatan sulfate in all three cuff tendons was approximately 1. Rotator cuff tendons contained large proteoglycan similar to aggrecan, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel migration, elution from Sepharose CL-4B, and content of both chondroitin sulfate and keratan sulfate chains. Both decorin and biglycan were also present, as demonstrated by migration in sodium dodecyl sulfate-polyacrylamide gels and core protein immunoreactivity. In contrast, decorin was the only proteoglycan prominent in distal/tensional regions of biceps tendon. Histological analysis showed layers of loosely organized, alcian blue-stained material running between the longitudinal collagen fiber bundles. The proteoglycan content of rotator cuff tendons was similar to fibrocartilage in tendons that have been subjected to compressive loads in situ. This suggests that cells of normal adult rotator cuff tendons have adapted to loads distinct from pure tension. However, the histological organization did not resemble mature fibrocartilage. The increased amount of proteoglycan in rotator cuff tendons may serve to separate and lubricate collagen bundles as they move relative to each other during normal shoulder motion.     

Erythropoietin structure-function relationships: high degree of sequence homology among mammals

To investigate structure-function relationships of erythropoietin (Epo), we have obtained cDNA sequences that encode the mature Epo protein of a variety of mammals. A first set of primers, corresponding to conserved nucleotide sequences between mouse and human DNAs, allowed us to amplify by polymerase chain reaction (PCR) intron 1/exon 2 fragments from genomic DNA of the hamster, cat, lion, dog, horse, sheep, dolphin, and pig. Sequencing of these fragments permitted the design of a second generation of species-specific primers. RNA was prepared from anemic kidneys and reverse-transcribed. Using our battery of species-specific 5' primers, we were able to successfully PCR- amplify Epo cDNA from Rhesus monkey, rat, sheep, dog, cat, and pig. Deduced amino acid sequences of mature Epo proteins from these animals, in combination with known sequences for human, Cynomolgus monkey, and mouse, showed a high degree of homology, which explains the biologic and immunological cross-reactivity that has been observed in a number of species. Human Epo is 91% identical to monkey Epo, 85% to cat and dog Epo, and 80% to 82% to pig, sheep, mouse, and rat Epos. There was full conservation of (1) the disulfide bridge linking the NH2 and COOH termini; (2) N-glycosylation sites; and (3) predicted amphipathic alpha- helices. In contrast, the short disulfide bridge (C29/C33 in humans) is not invariant. Cys33 was replaced by a Pro in rodents. Most of the amino acid replacements were conservative. The C-terminal part of the loop between the C and D helices showed the most variation, with several amino acid substitutions, deletions, and/or insertions. Calculations of maximum parsimony for intron 1/exon 2 sequences as well as coding sequences enabled the construction of cladograms that are in good agreement with known phylogenetic relationships.     

The evolution of benign arterionephrosclerosis from age 6 to 70 years.

Arterionephrosclerosis is diagnosed at autopsy by assessing the severity and extent of certain structural features in the renal cortical arteries seen in tissue sections. These features are characterized by fibrotic intimal thickening and medial shrinkage, a progressive change from the youthful muscular pattern to the elderly sclerotic pattern. Intimal fibrosis can be quantified by expressing intimal thickness as a percentage of the arterial outer diameter (% OD). The magnitude of arterionephrosclerosis, found by averaging the measures of intimal fibrosis seen in a kidney, can be calculated from age and mean blood pressure, using a standard prediction function. This function is a quantitative statement of a fundamentally important principle: just as blood pressure is a continuous variable that can range from low to high levels, arterionephrosclerosis is also a continuous variable that can take any degree of abnormality of arterial structure from minimal to maximal. Furthermore, a correspondence exists between the two quantities so that each can be calculated from the other. In this study, a correlation of 0.966 was found between the observed and the calculated magnitudes of arterionephrosclerosis over 10-year age groups from 25 to 34 years to 65 to 74 years, using group average data within age groups. For individuals, however, the correlations between observed and calculated magnitudes of arterionephrosclerosis were about 0.6 in a former study of elderly subjects and about 0.1 in the subjects aged 6 to 27 years in this study. The average growth rate of arterionephrosclerosis was found to be about 0.25 %OD per year from ages 15 to 54 years, and about 0.13 %OD per year from ages 55 to 70 years; the growth rate did not increase in the oldest age groups when blood pressure averaged higher than blood pressure in more youthful subjects. These and other findings are consistent with the view that the reason a correlation exists between blood pressure and arterionephrosclerosis could be because the magnitude of arterionephrosclerosis is one of the determinants that sets the level of blood pressure. From this perspective, each individual can be viewed as having other determinants of blood pressure, methodologic or biologic, which add to or subtract from the values set by age and arterionephrosclerosis. When subjects are pooled into groups, so that individual determinants balance out, the group average levels of mean blood pressure could be interpreted as reflecting little other than the magnitude of arterionephrosclerosis at each specific age.     

鼓槌石斛中一新的联苄类化合物——鼓槌石斛素

从兰科鼓槌石斛(Dendrobium chrysotoxum)中分得一新的联苄类化合物,经光谱分析(UV,IR,MS,¹HNMR,¹³CNMR和DIFNOE),其结构确定为4-羟基-3,5,3',4'-四甲氧基联苄,命名为鼓槌石斛素。关键词鼓槌石斛;鼓槌石斛素;联苄类化合物。     

Methamphetamine-induced ischemic colitis.

A 50-year-old woman with acute onset of right lower quadrant pain and hematochezia proved to have segmental ischemic colitis associated with methamphetamine abuse. The diagnosis was established by colonoscopy with biopsy, and abdominal angiography revealed no thrombosis, vasculitis, or vasospasm. The condition resolved within 10 days. Since methamphetamine abuse is increasing, physicians should be aware of its potential to produce intestinal ischemia.     

A qualitative and quantitative analysis of the entorhinal cortex in schizophrenia

The entorhinal cortex (ERC) has been implicated in schizophrenia by a number of studies. There is anatomical observation of neuronal heterotopias in the rostral ERC, which is consistent with a hypothesis of neurodevelopmental abnormalities in this disease. In view of the significant cytoarchitectonic variation of the ERC throughout its rostro-caudal extent, we performed a detailed subareal analysis of the rostral two-thirds of the entorhinal cortex (ERCr) in 14 postmortem schizophrenic brains and 14 matched controls (mean ages of 48 and 47 respectively). This systematic evaluation included both a qualitative microscopic analysis of morphogenetic anomalies that would be consistent with neurodevelopmental pathology and quantitative measurements of total neuronal number, average neuronal density, laminar volume and laminar depth from the cortical surface in cytoarchitectonically matched subareas of schizophrenic and control brains. Parcellation of the entire ERC on the basis of cytoarchitectonic criteria identified five distinct regions, similar to those described in the macaque, except that in the human brain three of the regions were further divisible into two or three subareas, yielding nine distinct cellular compartments. Five rostral areas, prorhinal (Pr), lateral (28L), intermediate rostral and caudal (281r and 281c), and sulcal (28S), comprise the ERCr. Gross and microscopic examination of these subdivisions throughout the ERCr failed to reveal laminar disorganization in any of the schizophrenic brains. The brains also did not differ significantly with respect to total neuronal number, total volume and neuronal density per laminar and subareal subdivision, or laminar thickness per entorhinal subarea. However, neuronal number and density were reduced by 12-18% in Pr and 28L, suggesting that mild quantitative abnormalities may exist in the ERCr and might possibly be revealed in a larger sample of schizophrenic brains. We have failed to confirm previous reports of laminar disorganization in the ERCr in brains of patients with schizophrenia; to the extent that this region is implicated in schizophrenia, the structural changes are likely to consist of more subtle cellular disturbances.