Purification and characterization of a lipolytic enzyme active at low temperature from Norwegian Typhula ishikariensis group III strain

An extracellular lipolytic enzyme active at low temperature was purified from the culture filtrate of the snow mold fungus, Typhula ishikariensis group III, strain 6-1-1. The molecular mass of enzyme was approximately 83 kDa (SDS-PAGE). The lipolytic enzyme was most active for p-nitrophenyl palmitate at 30 –C (pH 9.0). The lipolytic activity was 23.4% of the maximum at 4 –C, the temperature of culture. Thus, the isolated T. ishikariensis lipolytic enzyme is thought to represent a new member of a group of enzymes active at low temperature.     

Crude extract of the cyanobacterium, Hapalosiphon sp., causes a cessation of root elongation and cell division in several plant species

The phytotoxic activities of the crude extract from the cyanobacterium, Hapalosiphon sp., on the initial growth and root cell division of several plant species were investigated. Although the germination percentages of the plants were not affected by the extract, their root and shoot growth were remarkably suppressed, depending on the extract concentrations. Roots were more sensitive to the extract than shoots and the sensitivity, determined by the I₅₀ concentrations between the susceptible and tolerant species, differed by 5 and 11 times in dicotyledonous and monocotyledonous plants, respectively. The mitotic index for wheat ( Triticum aestivum L. cv. Norin 61) root cells was not affected, but the mitotic index for onion ( Allium cepa L. cv. Raputa II) was reduced with the increasing concentration of the extract. In the onion root meristem, the number of cells in prophase, metaphase, anaphase, and telophase were decreased significantly with 6 g DW L⁻¹ (g dry weight of algae L⁻¹). This suggests that the extract might inhibit the processes regulating the entry of cells into mitosis.     

Ecological characterization of three different phylogenetic groups belonging to the cellulolytic bacterial species Fibrobacter succinogenes in the rumen

To study the group‐dependent ecology of Fibrobacter succinogenes in the rumen, real‐time polymerase chain reaction assays for two phylogenetic groups (groups 2 and 3) of F. succinogenes were newly established and applied to rumen samples. Both the assays targeting the bacterial 16S rDNA were sensitive and accurate, showing wide quantifiable ranges (10⁴?10⁹ and 10²?10⁹ copies of 16S rDNA) and high recoveries of known amounts of added DNA (96.9 and 98.0%). The quantity of group 1 was confirmed to be numerable by subtracting assay values of groups 2 and 3 from that of F. succinogenes species (groups 1–3). By using the developed assays and the above subtractive calculation, the quantities of all three groups were evaluated in solid and liquid fractions of the rumen content and also on hay stems. In the solid fraction, groups 1 and 2 were abundantly present, compared with group 3 (P < 0.05). On untreated hay stems, group 1 was dominant throughout 48 h. In addition, group 1 showed growth even on the cellulase‐treated hay stems, unlike the other two groups. These results suggest that F. succinogenes group 1 greatly contributes to rumen fiber digestion, even for less degradable materials.     

Chondrocyte apoptosis and decrease of glycosaminoglycan in cranial cruciate ligament insertion after resection in rabbits

We examined time-dependent histological changes of the calcified fibrocartilage area in a tibial cranial cruciate ligament (CCL) insertion after ligament resection in rabbits. The animals were divided into two groups: those undergoing CCL substance resection in the right stifle (resected group) and those receiving the same operation without CCL resection in the left stifle (sham operated group). Five animals were euthanized with deep anaesthesia at four time periods (1, 2, 4 and 6 weeks), and Haematoxylin-eosin and Safranin-O stainings and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining were performed. The average percentage of TUNEL-positive chondrocytes and the average thickness of the glycosaminoglycan (GAG)-stained area in the calcified fibrocartilage area were measured. Two and 4 weeks after the surgery, the average percentages of TUNEL-positive chondrocytes in the resected group (23.8 +/- 10.3% and 15.9 +/- 6.7%, respectively) were significantly higher than those in the sham operated group (8.9 +/- 3.8% and 7.4 +/- 1.6%, P<0.05, respectively). Six weeks after the surgery, the average thickness of the GAG-stained area in the resected group (7.7 +/- 13. 5 microm) was significantly smaller than that in the sham operated group (69.4 +/- 39.9 microm, P<0.05). Our results suggest that the average percentage of TUNEL-positive chondrocytes became a peak in 2 weeks and that histological changes occurred in 6 weeks. The chondrocyte apoptosis can induce decrease of GAG-stained area after resection of CCL. Therefore, chondrocyte apoptosis in the calcified cartilage area in the CCL tibial insertion might lead to histological changes.     

Influence of preemptive analgesia with meloxicam before resection of the unilateral mammary gland on postoperative cardiovascular parameters in dogs

Preemptive analgesia is recommended in small animal medicine. However, many studies have evaluated the response to analgesic treatment by behavioral observation. Therefore, the influence of preemptive analgesia with meloxicam on postoperative cardiovascular and renal parameters remains to be clarified. The present study examined the changes in blood pressure, heart rate, double product and heart rate variability for 14 days and the changes in glomerular filtration rate (GFR) and serum cortisol level for 24 hr after resection of the unilateral mammary gland in meloxicam and control groups consisting of 5 healthy dogs. All data were collected under unanesthetized and unrestrained conditions using a radio telemetry system. Blood pressure, heart rate and double product were significantly lower in the meloxicam compared with the control group, and the meloxicam group's diurnal changes became stable more than 36 hr earlier than those of the control group. The systolic, diastolic and mean blood pressure values of the meloxicam group were 5- to 20-mm Hg lower than those of the control group until 5 days after surgery. The maximum difference between the two groups in terms of the double product values 14 days after surgery was 2,000 bpm x mmHg. Autonomic activity inhibition was prolonged in the control group. There were no significant differences in the 24-hr changes in GFR or serum cortisol level. This study showed that perioperative administration of meloxicam reduced unfavorable postoperative changes in the cardiovascular system without influencing renal function.     

Swine abortion caused by Candida parapsilosis

In July 2020, a sow in a breeding herd in the Chiba Prefecture, Japan, suffered abortion. A necropsy revealed pale pulmonary foci scattered in the two fetuses. Histologically, multifocal pulmonary necrosis was detected with numerous yeasts. The yeast was positively stained using the periodic acid-Schiff reaction and Grocott’s silver stain. Molecular identification indicated that the yeast was Candida parapsilosis. In conclusion, our results suggested that C. parapsilosis caused multifocal necrotizing pneumonia in the two fetuses. This study is the first report of a swine abortion with C. parapsilosis infection.     

Right ventricular systolic and diastolic function assessed by two-dimensional speckle tracking echocardiography in dogs with myxomatous mitral valve disease

Pulmonary hypertension (PH) is a common comorbidity in dogs with myxomatous mitral valve disease (MMVD), and can induce various changes in the right heart, such as right ventricular (RV) hypertrophy, dilatation, and dysfunction. We hypothesized that RV function, not only systolic function but also diastolic function, could be worsened with PH progression. We aimed to compare RV systolic and diastolic function in dogs with MMVD. Twenty healthy dogs and sixty-eight dogs with MMVD were enrolled. Dogs with MMVD were classified into the probability of PH. Two-dimensional and Doppler echocardiographic indices for right heart and two-dimensional speckle tracking echocardiography indices were measured. The morphological indicators of the right heart were significantly higher only in the high probability of PH group. The RV strain, early-diastolic and systolic strain rates were significantly lower in the high probability of PH group than those in the low and intermediate probability of PH groups. Multivariate analysis showed that increased RV internal dimension normalized by body weight and RV myocardial performance index were significantly associated with the presence of right-sided congestive heart failure. Speckle tracking echocardiography-derived RV systolic and diastolic function were activated in the low and intermediate probability of PH groups. However, dogs with high probability of PH showed RV myocardial dysfunction and dilatation. Increased RV myocardial performance index and end-diastolic RV internal dimension normalized by body weight were significantly associated with the presence of right-sided congestive heart failure in dogs with MMVD.     

氧漂过程中脱木质素与木质素氧化之间定量关系的研究

对氧碱漂白过程中木质素氧化进行定量分析,分析方法是基于氧化前后高锰酸钾消耗量的变化。该方法对溶出残余木质素的氧化结果分析发现其呈明显3个阶段：第一段木质素氧化的当量电荷数约4～5／木质素单元;木质素总氧化电荷数大约为9／木质素单元。这些数据以及甲氧基的脱除（75％）均表明：木质素的氧化不仅发生在酚型木质素单元,同时也发生在非酚型结构单元上。只有第一阶段氧化反应是木质素与氧气直接反应,而在第二、三阶段主要是协同氧化作用,氧化反应过程中产生的活性氧基团扮演了一定角色。通过对低浓度针叶材硫酸盐浆的氧漂研究发现：当卡伯值下降一半（25．4至13．4）时平均每个木质素单元氧化3当量电子,氧漂后的纸浆中仍然有大量未被氧化的残余木质素。定量地证明了在氧漂过程中木质素氧化是脱木质素反应的实质。