Ultrastructure of the Erythrocytic Stages of Plasmodium malariae1

This report describes the fine structure of the erythrocytic stages of Plasmodium malariae. Erythrocytic parasites from a naturally acquired human infection and an experimentally infected chimpanzee were morphologically indistinguishable and structurally similar to other primate malarias. New findings included observations of highly structured arrays of merozoite surface coat proteins in the cytoplasm of early schizonts and on the surface of budding merozoites and the presence of knobs in the membranes of Maurer's clefts. Morphological evidence is presented suggesting that proteins are transported between the erythrocyte surface and intracellular parasites via two routes: one associated with Maurer's clefts for transport of membrane-associated knob material and a second associated with caveolae in the host cell membrane for the import or export of host- or parasite-derived substances through the erythrocyte cytoplasm.     

睾丸特异抗原C_2B细胞抗原决定簇的定位

免疫性不育病人的血清（ＩＰＳ）能１００％地抑制人体外受精．用该血清筛选人睾丸ｃＤＮＡ基因表达文库,发现了一种新的睾丸特异抗原（称作Ｃ２）．通过ＤＮＡ顺序研究,并与基因库中的有关同源性基因数据进行比较,证实Ｃ２是一个新的特异蛋白．Ｃ２基因仅与睾丸组织的ｍＲＮＡ杂交．该克隆在大肠杆菌中所表达的融合蛋白能够被３个不同的不育病人血清识别．利用嵌套缺失和Ｗｅｓｔｅｒｎ印迹的方法研究其抗原决定簇定位,发现Ｂ细胞抗原决定簇在羧基端２９个氨基酸范围内．用ＧＣＧ软件分析该抗原的氨基酸的亲水性和疏水性以及其存在于蛋白表面的可能性,确定其中的１５个氨基酸为抗原决定簇所必需,并合成了多肽     

Development of the Recalcitrant (Homoiohydrous) Seeds of Avicennia marina: Anatomical, Ultrastructural and Biochemical Events Associated with Development from Histodifferentiation to Maturation

Early histodifferentiation of the embryo of Avicennia marina(Forssk) Vierh was characterized by the formation of endospermhaustoria Once the growth phase was initiated, subsequent embryodevelopment was extra-ovular The mature seed, therefore, wasenclosed by a pericarp originating entirely from the ovary wallGrowth and reserve deposition was not initiated until 45–50d after fruit set (DAFS), when respiratory activity had peakedWater content remained constant from the earliest stages ofembryogenesis to seed abscission and respiratory activity, althoughdeclining somewhat after the completion of histodifferentiation,remained relatively high throughout seed development The ultrastructureof the meristematic root primordia was indicative of metabolicactivity, remaining essentially similar in all respects fromthe end of histodifferentiation until the mature seeds wereabscised During this phase cotyledon cells became highly vacuolatedand the soluble sugars, which constituted the major nutrientreserves of mature seeds, increased considerably Seeds of A,marina initiate germination, without the requirement for additionalwater, as soon as they are shed It is proposed that the accumulationof soluble sugars, rather than insoluble complex reserves, isa major factor in the developmental strategy of these highlyrecalcitrant seeds Anatomy, Avicennia marina, biochemistry, homoiohydrous, recalcitrant, seed development/maturation, ultrastructure     

C-Type Virus associated with Gibbon Lymphosarcoma

C-TYPE viruses have been established as the causal agents of leukaemia in murine and feline species and have been characterized^1,2. C-type virus is also probably associated with fibrosarcoma in non-human primates^3–6. To determine whether viruses with identical characteristics are associated with other neoplasms in simian species, we looked for C-type viruses in cases of leukaemia. A gibbon (Hylobates lar) with a disseminated tumour (later confirmed as lymphosarcoma) was made available to the Comparative Oncology Laboratory by Dr Malcolm Jones of the University of California, San Francisco Medical Center. The principal sites of involvement (lymph node, liver and bone marrow) were extensively overrun with massive neoplastic cells, which were predominantly prolymphocytic forms. Electron microscopy revealed C-type particles identical to those observed in vitro in sections from lymph nodes, liver, spleen and bone marrow.     

Chorionic sculpturing in some sandfly eggs (Diptera,Psychodidae)1

The outer chorionic sculpturing of the eggs of thirteen species of neotropical sandflies was examined by scanning electron microscope. Sculpture patterns are species specific and include polygons, parallel ridges and mountain or volcano-like structures. Two closely related and undescribed species of the intermedia group were distinguished by this means. The role of sculpturing in plastron respiration is discussed.