Sampling bias in studies of dentoalveolar pathology in past human populations

Two subsamples of 30 subjects drawn from the same skeletal population (Monte d'Argento, Italy, Medieval age) were examined in a parallel blind study of dentoalveolar pathology, tooth wear and calculus, in order to assess the influence of sampling bias on dietary reconstruction. The effect of interobserver error was controlled and random subdivision was performed on a sample homogeneous for age and social condition. In spite of this, appreciable differences in the frequencies of some pathologies and, therefore, in dietary reconstruction were found, thus pointing to potential effectiveness of sampling bias in archaeological partial samples.     

Quantitative analysis of muscle breakdown during starvation in the marine flatfish Pleuronectes platessa

Summary The present study describes the effects of starvation for a duration of four months on the ultrastructure of skeletal muscles from the marine flatfish (Pleuronectes platessa L.). Starvation is associated with a decrease in resting metabolic rate from 20.1±2.2 to 11.6±1.5mg-O₂/kg/h (P<0.05) and muscle wasting. Median fibre size fell from 700 m² to 500 m² in intermediate (fast oxidative) and from 1,800 m² to 600 m² in starved, white (fast-glycolytic) muscle fibres. In contrast, median fibre size in red (slow oxidative) muscle remained within the range 300–400 m². The fraction of red fibre volume occupied by myofibrils (58.6%) and mitochondria (24.5%) did not change significantly with starvation. There was, however, a decrease in stored lipid (10.7% to 3.2%) and an alteration in the structure of the cristae in mitochondria from red muscle.Atrophy of white muscle fibres is associated with a decrease in both the diameter and fractional volume occupied by myofibrils (85.7% to 61.9% P < 0.01). In a high proportion of white fibres peripheral degeneration of Z-discs is evident causing an unravelling of the thin filament lattice. It is suggested that this allows a partial decrease in myofibril diameter and hence the maintenance of contractile function in muscle from starved fish. In severely degenerating white fibres, disorganised thick and thin filaments and numerous multimembrane lysosome-like vesicles are observed.Starvation results in an increase in the average content of mitochondria in white fibres from 2.2 to 6.7% (P<0.01). In fed plaice mitochondria constitute less than 1% of the volume of the white fibre in 43.5% of the fibres. The proportion of white fibres containing more than 6% mitochondria increases from 6.5% to 58% with starvation.     

Brugia malayi,Brugia pahangi, and Brugia patei: Pulmonary pathology in jirds, Meriones unguiculatus

The chronological development of pulmonary lesions due to subperiodic Brugia malayi and related species was studied in the jird, Meriones unguiculatus. Major pathologic changes included (1) granulomas induced by larvae and adults, (2) obstructive endarteritis, and (3) chronic interstitial inflammation with degenerating microfilariae. The majority of pulmonary granulomas were initiated near the time of the final molt, about 30 days postinoculation, followed by involution and formation of residual vascular lesions over the next several months. A minority of granulomas arose about sexually mature adult worms and showed a characteristic sequence of development along the length of these worms. Ultrastructural observations suggested that within granulomas internal structures of the worm underwent an autolytic-like disintegration, while the cuticle remained intact. A material, presumably of parasitic origin, then appeared between the cuticle and adherent epitheloid and giant cells and was subsequently phagocytized by these cells. Obstructive endarteritis appeared to peak at about the time of the final molt, and became largely fibrotic by 125 days postinoculation; electron microscopy of the subintimal infiltrates revealed a variety of cells including inflammatory cells and others interpreted as modfied cells of vascular origin (smooth muscle cells and two types of endothelial cells).Parasitological data suggested that both larvae and adults migrated to the lungs and that mating occurred here, rather than in peripheral sites of development. In terms of development, reproduction and survival, the pulmonary arteries of the male jird offered a suitable alternative for the localization of these primarily lymphatic filariae; our results thus suggest that the pulmonary localization of these worms should not be considered indicative of an aberrant mode of development. The failure of female jirds to develop detectable peripheral microfilaremia was associated with a high rate of infertility among female worms, rather than pulmonary sequestration or destruction of microfilariae.     

Biochemical characterization of the microsporidian Nosema bombycis spore proteins

Spore proteins of the microsporidian Nosema bombycis, from the silkworm Bombyx mori, were analysed by SDS–polyacrylamide gel electrophoresis. The protein profile of partially solubilized spores showed three major peptide bands of molecular weight 68, 94 and 100 kDa. On complete solubilization, it showed peptide bands ranging from 17 to 68 kDa. Attempts to purify the 17 kDa infection-specific protein showed aggregation of this protein to higher molecular size proteins. Partial peptide analysis of the different peptides exhibited similar patterns suggesting the probablity of processing during the infective cycle. Reconstitution assay showed the reversible nature of this processing. N-terminal sequencing showed homology to heat shock proteins. The low molecular weight 17 kDa protein also showed very high protease activity.     

Ultrastructural Localization of Acid Phosphatase Activity in Soybean Cotyledon Cells

In the cotyledon cells of the developing seeds (35～50 d after flowering) and the early germinating seeds (4 ～ 8 d after sowing) of soybean (Glycine max L. ), acid phosphatase (APase) activity was mainly deposited in the protein bodies (PB) and in endoplasmic reticulum (ER). In addition, in the early developing cotylendon cells, the prominent reaction product of APase activity was seen along the plasma membrane, in the cell wall and within the vesicles in the cytoplasm adjancent to the plasma membrane. And some of the vesicles seemed to be fused with the plasma membrane.     

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.     

Skeletal evidence of health and disease in pre-contact Alaskan Eskimos and Aleuts

There have been relatively few paleopathological studies of arctic populations to date, compared to other regions of North America. Studies aimed at elucidating patterns of health and disease in arctic peoples prior to contact and assessing inter- and intraregional differences in disease patterns have been particularly few. In the present study, five pre-contact skeletal samples (N = 193), representing 4 Eskimo populations from northern coastal Alaska and 1 Aleut population from the eastern Aleutian Islands, were examined macroscopically for the following indicators of health status: cribra orbitalia, porotic hyperostosis, trauma, infection, dental caries, abscesses, antemortem tooth loss, periodontal disease, and dental attrition. In addition, archeological and epidemiological data were used to help reconstruct the health of these populations. The goals of the analysis were 2-fold: 1) to assess the pre-contact health of North Alaskan Eskimos and Aleuts in order to provide a baseline comparison for the post-contact health of these groups, and 2) to determine if any differences in disease patterns exist between the Eskimos and Aleuts that might be related to differences in their physical environment, subsistence patterns, and cultural practices. The analysis revealed that both groups suffered from a variety of health problems prior to contact, including iron deficiency anemia, trauma, infection, and various forms of dental pathology. Statistical comparisons of the 2 groups revealed that Eskimos and Aleuts had different patterns of health and disease prior to contact. Most notably, the Aleuts had a significantly higher frequency of cranial trauma and infracranial infection than the Eskimos, while the latter had a significantly higher frequency of enamel hypoplasia. An examination of the physical and cultural environment of the 2 groups reveals several possible explanations for these differences, including warfare, subsistence pursuits, and housing practices. The documentation of these differences indicates that variability in pre-contact disease patterns can be identified between hunter-gatherer populations living in similar environments and exhibiting similar general lifestyles. Am J Phys Anthropol 107:51–70, 1998. © 1998 Wiley-Liss, Inc.     

《农业植物病理学》课程网站的建设

在进行区级精品教材—《农业植物病理学》(华南本)的编著工作的同时,开展了《农业植物病理学》课程网站的开发设计,提出了网站的设计思路及网站建设的方法,并就其测试效果及性能进行了分析。