Ultrastructural localization of dipeptidyl peptidase IV in rat salivary glands by immunocytochemistry

Summary The ultrastructural localization of dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5) in rat submandibular and parotid glands was studied immunocytochemically by the peroxidase-antiperoxidase (PAP) method, using a monospecific antiserum against rat kidney DPP IV. There were no differences in the immunocytochemical localization of DPP IV between submandibular and parotid glands. In these glands, DPP IV was primarily found to be associated with the luminal and intercellular canalicular plasma membranes of acinar cells and with the luminal plasma membranes of intercalated and striated duct cells. Occasionally, immunoreaction of DPP IV was detected in cytoplasmic vesicles (vacuoles), lysosomes, and multivesicular bodies in some acinar cells as well as in ductal epithelial cells. Furthermore, the reaction product was also found within the lumina of peri-acinar and peri-ductal capillaries and in the cytoplasm of some fibroblasts in the interstitial connective tissue. These data suggest that DPP IV in the submandibular and parotid glands may play some role in the secretion or reabsorption processes of secretory proteins and peptides in these glands.     

Inflammatory arthritis in Pongo

Abstract: As the arboreal ape, Pongo, has an unusual ground ambulation adaptation, it was of interest to assess the impact of Pongo gait on patterns of arthritis. While osteoarthritis was not identified in Pongo, 11% of individual skeletons were afflicted with an inflammatory, erosive arthritis. The presence of sacroiliac involvement and the nature and distribution of erosive lesions allowed definitive diagnosis of spondyloarthropathy. Character, distribution, and radiologic appearance revealed a picture distinguishable from spondyloarthropathy in other primates.     

Ultrastructural study of spermiogenesis in a rare desert amphisbaenian Diplometopon zarudnyi

Spermiogenesis, in particular the head differentiation of Diplometopon zarudnyi, was studied at the ultrastructural level by Transmission Electron Microscope (TEM). The process includes acrosomal vesicle development, nuclear elongation, chromatin condensation and exclusion of excess cytoplasm. In stage I, the proacrosomal vesicle occurs next to a shallow fossa of the nucleus, and a dense acrosomal granule forms beneath it. This step commences with an acrosome vesicle forming from Golgi transport vesicles; simultaneously, the nucleus begins to move eccentrically. In stage II, the round proacrosomal vesicle is flattened by projection of the nuclear fossa, and the dense acrosomal granule diffuses into the vesicle as the fibrous layer forms the subacrosomal cone. Circular manchettes surrounded by mitochondria develop around the nucleus, and the chromatin coagulates into small granules. The movement of the nucleus causes rearrangement of the cytoplasm. The nucleus has uniform diffuse chromatin with small indices of heterochromatin. The subacrosome space develops early, enlarges during elongation, and accumulates a thick layer of dark staining granules. In stage III, the front of the elongating nucleus protrudes out of the spermatid and is covered by the flat acrosome; coarse granules replace the small ones within the nucleus. One endonuclear canal is present where the perforatorium resides. In stage IV, the chromatin concentrates to dense homogeneous phase. The circular manchette is reorganized longitudinally. The Sertoli process covers the acrosome and the residues of the cytoplasmic lobes are removed. In stage V, the sperm head matures.     

KIF2C exerts an oncogenic role in nonsmall cell lung cancer and is negatively regulated by miR‐325‐3p

Nonsmall cell lung cancer (NSCLC) is one of the leading causes of cancer‐related death worldwide. Kinesin family member 2C (KIF2C), a modulator in microtubule depolymerization, bipolar spindle formation, and chromosome segregation, has been reported to take roles in cancer biology, but its role in NSCLC remains unclear. This study was intended to investigate the expression and function of KIF2C in NSCLC. Our results demonstrated that KIF2C was up‐regulated in NSCLC tissues and cell lines. The high expression of KIF2C in NSCLC tissues was significantly correlated with higher T stage (0.0078), worse differentiation status (0.0049), and lymph node metastasis (P < .0001). We also proved that the high expression level of KIF2C predicted worse prognosis of the patients. After knockdown of KIF2C, the proliferation and metastasis of NSCLC cells were inhibited. Luciferase reporter assay suggested that KIF2C was a target gene of miR‐325‐3p, which was reported to be a tumour suppressor in NSCLC. In conclusion, this study proved an oncogenic role of KIF2C in NSCLC and partly clarified the mechanism of its high expression. Our findings provided a useful insight into the mechanism of NSCLC progression and offered clues to novel therapy strategies.     

Development of remote sensing indicators for mapping episodic die-off of an invasive annual grass (Bromus tectorum) from the Landsat archive

The exotic annual grass Bromus tectorum (cheatgrass) dominates vast acreages of rangeland in the western USA, leading to increased fire frequency and ecosystem degradation that is often irreversible. Episodic regeneration failure (“die-off”) has been observed in cheatgrass monocultures and can have negative ecosystem consequences, but can also provide an opportunity for restoration of native species and ecological function within the imperiled sagebrush steppe ecosystem. Proximate causes of cheatgrass die-off are uncertain, although several taxa of fungal soil pathogens have been implicated. Die-off occurrence is stochastic and can occur in remote areas. Thus, developing remote sensing indicators that are repeatable over long time periods, across extensive regions, and at relatively fine spatial resolution would be beneficial for accurately pinpointing events.We developed a remote sensing approach for mapping historical die-off from the Landsat archive (1985–2015), and used this to quantify spatial and temporal patterns of die-off occurrence annually at 30-m resolution. A Random Forests classification of image-derived spectral endmembers, trained on 2014 data, predicted die-off with 93% accuracy (κ = 0.845) when applied to independent validation data from 2009. Die-off extent varied greatly across years, though some areas experienced die-off multiple times during the observation period. We found a strong correspondence between die-off occurrence and winter drought conditions, with strongest negative associations with current-year winter precipitation and previous years’ lagged winter and annual precipitation. Die-off duration was heavily skewed towards single-year die-off (81.5% of events), even in localized areas of more frequent occurrence (‘die-off hotspots’).Our retrospective classification of the Landsat archive suggests that cheatgrass die-off occurrence is predictable as the intersection of particular site environmental conditions with annual weather conditions, possibly because they are favorable for disease expression. Associations with previous year conditions suggest that die-off may also depend upon feedbacks between cheatgrass dominance and litter production, suitable sites for seedling establishment, and abundance and persistence of pathogen inoculum. Remote sensing indicators such as those developed in this study are needed to develop hypotheses about die-off causal factors, as well as support improved management of cheatgrass, mitigation for negative consequences associated with die-off (e.g. wind erosion), and successful restoration of native plant communities on die-off areas.     

Ascaris suum: Nutrient absorption,growth, and intestinal pathology in young pigs experimentally infected with 15-day-old larvae

Three-week-old pigs on high (HP) or low (LP) protein diets were infected with 15-day-old Ascaris suum larvae (W). Including noninfected pigs (C), the experimental groups were HPW, LPW, HPC, and LPC. After 8 weeks, worm burden in the intestine averaged 42 in LPW and 31 in HPW. Nitrogen balance during Week 4 showed nonsignificantly less nitrogen absorption and retention in LPW compared to LPC. A similar, nonsignificant decrease in fat absorption was recorded in LPW vs LPC and in HPW vs HPC. The weight of the small intestine was significantly greater in W than C pigs but did not differ because of protein level. The weight correlated positively to worm burden and the increase was due mainly to hypertrophy of the tunica muscularis (muscle layers).     

Phocanema decipiens: Intestinal penetration in the laboratory rat

Larval Phocanema decipiens from cod muscles were fed singly or repeatedly to Sprague-Dawley rats and the condition of the rats was monitored. Rats given two larvae each week for 10 weeks were considered to be sensitized. “Sensitized” and “naive” rats were each exposed to larvae during laparotomy and the tissue pathology was examined from 5 hr to 14 days after penetration—no differences were found. This is evidence against the “two-hit hypothesis” of pathology resulting largely from prior sensitization of the host. The lesion was also comparable to that made in the intestine with a sterile pin. Tissue changes showed acute inflammation followed by monocyte infiltration and then fibrocytes and granulation tissue finally left a fibrotic scar. Penetration of larvae through exposed intestinal loops of anesthetized and laparotomized rats was described using a closed-circuit TV system. These records are related to potentiometric recordings of isolated larvae in which a mean mechanical force of 1 g was typical with a maximum of 3.5 g generated by the integrated movement of the whole body. A force of 10 to 12 g/mm² was needed to penetrate the mucosa, muscularis, and serosa. The movements of the host's intestine and the rhythmic probing of the larvae clearly facilitate penetration. The data are used to support the hypothesis that mechanical factors of the larval force and the strength of the intestine dominate the pathological potential of P. decipiens. It is concluded that P. decipiens presents a very small pathological potential to the intact human gastrointestinal tract.     

周脂素在糖尿病肾病大鼠肾组织中的表达

目的观察大鼠糖尿病肾病(diabetic nephropathy,DN)模型的特点和尿LN对早期DN的诊断价值,探讨周脂素(perilipin,Plin)在DN大鼠肾脏中的表达情况。方法将14只SD雄性大鼠随机分为对照组(普通饲料)和糖尿病肾病模型组(高糖高脂饲料),对照组6只,模型组8只,饲养4周后模型组按照30mg/kg剂量注射1%链脲佐菌素(STZ),检测血糖≥16.7mmol/L,糖尿病模型制作成功,继续喂养6周,检测24h尿蛋白≥30mg/kg,糖尿病肾病模型制作成功。考马斯亮蓝检测24h尿蛋白、ELISA测尿层粘连蛋白,HE染色观察肾组织的病理变化,Real-time PCR及Western blot检测肾脏组织中perilipin表达情况。结果模型鼠24h尿蛋白≥30mg/kg,糖尿病肾病大鼠模型制作成功。和对照组大鼠相比,模型组的肾重/体重比明显增高(P<0.05),尿量、尿层粘连蛋白于5周出现升高、24h尿蛋白于6周时出现升高,且三项指标均随着时间不断增高。肾组织病理检查显示:肾小球肥大,基膜增生,微小血管瘤形成,肾小管管腔变形,上皮脱落、空泡样变,大量单核、淋巴等炎性细胞浸润,间质内胶原纤维增生。模型组大鼠肾组织Plin的mRNA及蛋白表达均明显的升高(P<0.05)。结论尿层粘连蛋白比24h尿蛋白升高得早,可作为早期糖尿病肾病的警示指标。Plin表达增高可能参与了糖尿病肾病肾病变过程,为进一步探讨糖尿病肾病的发病机制提供新的思路。