Clues potentially distinguishing lytic lesions of multiple myeloma from those of metastatic carcinoma

This study was conducted to determine whether individual bony lesions are specific for recognizing multiple myeloma and thereby distinguish it from metastatic cancer and leukemia. The lytic skeletal lesions of multiple myeloma are characterized by sharply defined, spheroid lesions. They have smooth borders and effaced/erased trabeculae. Unique spheroid myeloma lesions appear to be responsible for the “punched out” appearance of affected bone. The total absence of remodeling in myeloma forms a contrast to irregular preservation of trabeculae and buttressing, isolated “fronts of” cortical bone “resorption” coalescing to confluence, and the “golf-ball surface” phenomenon observed in metastatic cancer. The uniform effacement of both cortical and trabecular bone in multiple myeloma also contrasts with some cortical preservation in metastatic cancer. Leukemic lesions are more numerous than those of myeloma, but they lack the latter's “space-occupied” appearance. The relatively small holes and “fronts of resorption” of leukemia are quite different from the “space-occupied” lesions of multiple myeloma. Uniform size is a characteristic traditionally attributed to the bone lesions of multiple myeloma. The occurrence of isolated examples of uniform size lesions in metastatic cancer and of variable size lesions in some individuals with multiple myeloma precludes unequivocal use of size in differential diagnosis. Fortunately, the newly recognized macroscopic characteristics appear to separate multiple myeloma from metastatic cancer, and also distinguish myeloma from leukemia. Am J Phys Anthropol 105:241–250, 1998. © 1998 Wiley-Liss, Inc.     

INVERSE RELATIONSHIP BETWEEN FUNCTIONAL MATURITY AND EXPONENTIAL GROWTH RATE OF AVIAN SKELETAL MUSCLE: A CONSTRAINT ON EVOLUTIONARY RESPONSE

In this study, we investigate whether a tissue-level constraint can explain the general inverse relationship between growth rate and precocity of development in birds. On the whole, altricial (dependent) chicks grow three to four times faster than the less dependent, more able chicks of precocial species of similar adult mass. We suggest that an antagonism between growth and acquisition of mature function in skeletal muscle constrains postnatal growth and development in most species of birds. Altricial species, represented by European starlings in this study, hatch with skeletal muscle having low capacity for generating force but grow rapidly. Conversely, precocial species (northern bobwhite quail and Japanese quail), hatch with relatively mature skeletal muscle, especially in their legs, but grow more slowly. As development proceeds in all species, exponential growth rates decrease as muscles acquire adult levels of function. Among four variables associated with muscle function, exponential growth rate (EGR) was negatively correlated with pyruvate kinase activity (glycolysis), potassium concentration (electrical potential), and dry weight fraction (contractile proteins) in both pectoral and leg muscles but not with citrate synthase activity (aerobic metabolism) in either set of muscles. For pectoral muscle, these variables accounted for 87% of the total variation in EGR in all three species combined despite a twofold difference in growth rates between the starling and quail. EGRs of leg muscle (51% of variation accounted for) were less than predicted by the pectoral-muscle equation in quail during the early part of the postnatal period and in starlings during the late postnatal period. This result would not contradict a growth rate/maturity constraint hypothesis if EGRs were down-regulated for allometric or other considerations.     

Muscle Stem Cells Exhibit Distinct Clonal Dynamics in Response to Tissue Repair and Homeostatic Aging

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Food preference, growth and maturation of Nemurella pictetii (Plecoptera: Nemouridae)

1. The stonefly Nemurella pictetii has a highly variable life cycle and is semi‐ and uni‐, but also plurivoltine in different geographical areas. 2. The influence of the type of food on growth and maturation of larvae was studied in laboratory experiments. Food preference was also assessed. 3. Larvae of N. pictetii are strongly opportunistic feeders utilising a broad range of food sources. However, biofilm was preferred over detritus (conditioned leaves), green algae and animal food. The highly mobile larvae quickly found the preferred food. Larvae fed on biofilm grew and developed significantly faster than larvae fed on conditioned leaves. 4. Larval growth and maturation in experiments as well as in the field differed with available food qualities. Phases of faster growth and maturation corresponded well with maximum availability of biofilm in the field. This contributes to the interpretations of differences in life cycles in the field.     

Dephosphorylation increases insulin-stimulated receptor kinase activity in skeletal muscle of obese Zucker rats

Serine/threonine phosphorylation of insulin receptor has been implicated in the development of insulin resistance. To investigate whether dephosphorylation of serine/threonine residues of the insulin receptor may restore the decreased insulin-stimulated receptor tyrosine kinase activity in skeletal muscle of obese Zucker rats, insulin receptor tyrosine kinase activity was measured before and after alkaline phosphatase treatment. Compared to lean controls, insulin-stimulated glucose transport was depressed by 61% (p < 0.05) in obese Zucker rats. The insulin receptor and insulin receptor substrate-1 contents were decreased by 14% (p < 0.05) and 16% (p < 0.05), respectively, in skeletal muscle of obese Zucker rats. In vivo insulin-induced tyrosine phosphorylation of insulin receptor and insulin receptor substrate-1 was depressed by 82% (p < 0.05) and 86% (p < 0.05), respectively. In the meantime, in vitro insulin-stimulated receptor tyrosine kinase activity in obese rats was decreased by 39% (p < 0.05). Dephosphorylation of the insulin receptor by prior alkaline phosphatase treatment increased insulin-stimulated receptor tyrosine kinase activity in both lean and obese Zucker rats, but the increase was three times greater in obese Zucker rats (p < 0.05). These findings suggest that excessive serine/threonine phosphorylation of the insulin receptor in obese Zucker rats may be a cause for insulin resistance in skeletal muscle.     

Mechanism of Enhanced Immature Dengue Virus Attachment to Endosomal Membrane Induced by prM Antibody

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Growth, maturation and photosynthesis of the brackish water alga Rhizoclonium sp. (Cladophoraceae, Chlorophyta) in relation to salinity

The effects of salinity on growth, maturation and photosynthesis were examined in the filamentous alga Rhizoclonium sp. (Cladophoraceae, Chlorophyta) growing in a brackish water habitat in a canal draining into Tokyo Bay, Japan. In this habitat Rhizoclonium sp. was exposed to a wide salinity range, both daily, 5–23‰ during November 1996, and hourly, 6–24‰ during the spring tide day. From the results of culture experiments, growth and maturation of Rhizoclonium sp. occurred in the wide salinity range of 10–40‰ at 20 μmol photons m‐²s‐¹ at 20°C, but did not occur at salinity of 0‰. Light saturation on the photosynthesis‐irradiance curve at 20°C at 20‰ was reached at 100 μmol photons m‐²s‐¹, which is characteristic for shade‐adapted algae. On the photosynthesis‐salinity curve at 20°C at saturated irradiance (160 μmol photons m‐²s‐¹), the net photosynthetic rate increased with increasing salinity up to 30‰ but decreased at 40‰. On the photosynthesis–salinity curve at 20°C at 20 μmol photons m‐²s‐¹ (at near in situ irradiance), the photosynthetic rates were almost the same in the salinity range from 0 to 40‰. Therefore, this species is able to grow, reproduce and photosynthesize with a relative efficiency in a wide salinity range, which shows that it is well adapted to a brackish water environment.     

论四射珊瑚包珊瑚科（AmplexidaeChapman,1893）的分类

讨论了包珊来龙去脉 科（ＡｍｐｌｅｘｉｄａｅＣｈａｐｍａｎ１８９３）的分类。把包珊瑚型隔型限于仅在外端连续,向轴部变薄呈短而低的脊状,纵向呈下连续的着生于横板之上。包珊瑚型隔壁的微细构造以层状骨骼为主,其轴部有时可出现非晶榍型纤状之骨骼,包括晶粒和短轴晶柱。     

Skeletal resorption in bryozoans: occurrence,function and recognition

Skeletal resorption – the physiological removal of mineralised parts by an organism – is an important morphogenetic process in bryozoans. Reports of its occurrence and function across the phylum are patchy, however, and have not previously been synthesised. Here we show that resorption occurs routinely across a wide range of bryozoan clades, colony sizes, growth forms, ontogenetic stages, body wall types, skeletal ultrastructures and mineralogies. Beginning in the early Paleozoic, different modes and functions of resorption have evolved convergently among disparate groups, highlighting its utility as a morphogenetic mode in this phylum. Its functions include branch renovation, formation of branch articulations, excavation of reproductive chambers, part‐shedding, and creation of access portals for budding beyond previously formed skeletal walls. Bryozoan skeletons can be altered by resorption at microscopic, zooidal and colony‐wide scales, typically with a fine degree of control and coordination. We classified resorption patterns in bryozoans according to the morphology and function of the resorption zone (window formation, abscission or excavation), timing within the life of the skeletal element resorbed (primary or secondary), and scale of operation (zooidal or multizooidal). Skeletal resorption is probably greatly underestimated in terms of its utility and role in bryozoan life history, and its prevalence across taxa, especially in fossil forms. It is reported proportionally more frequently in stenolaemates than in gymnolaemates. Some modes of resorption potentially alter or remove the spatial–temporal record of calcification preserved within a skeleton. Consequently, knowledge that resorption has occurred can be relevant for some common applications of skeletal analysis, such as palaeoenvironmental interpretation, or growth and ageing studies. To aid recognition we provide scanning electron microscopy, backscattered electron scanning electron microscopy and transmission electron microscopy examples of skeletal ultrastuctures modified by resorption.