Forest biomass carbon pool dynamics in Tibet Autonomous Region of China: Inventory data 1999-2019.

According to the forest resources inventory data for different periods and the latest estimation parameters of forest carbon reserves in China, the carbon reserves and carbon density of forest biomass in the Tibet Autonomous Region from 1999 to 2019 were estimated using the IPCC international carbon reserves estimation model. The results showed that, during the past 20 years, the forest area, forest stock, and biomass carbon storage in Tibet have been steadily increasing, with an average annual increase of 1.85×104 hm2, 0.033×107 m3, and 0.22×107 t, respectively. Influenced by geographical conditions and the natural environment, the forest area and biomass carbon storage gradually increased from the northwest to the southeast, particularly in Linzhi and Changdu, where there are many primitive forests, which serve as important carbon sinks in Tibet. In terms of the composition of tree species, coniferous forests are dominant in Tibet, particularly those containing Abies fabri, Picea asperata, and Pinus densata, which comprise approximately 45% of the total forest area in Tibet. The ecological location of Tibet has resulted in the area being dominated by shelter forest, comprising 68.76% of the total area, 64.72% of the total forest stock, and 66.34% of the total biomass carbon reserves. The biomass carbon storage was observed to first increase and then decrease with increasing forest age, which is primarily caused by tree growth characteristics. In over-mature forests, trees' photosynthesis decreases along with their accumulation of organic matter, and the trees can die. In addition, this study also observed that the proportion of mature and over-mature forest in Tibet is excessively large, which is not conducive to the sustainable development of forestry in the region. This problem should be addressed in future management and utilization activities.

Comparison of mannitol and hypertonic saline in treatment of intracranial hypertension of rabbits / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To compare the effects of mannitol and hypertonic saline (HS) in treatment of intracranial hypertension (ICH) of rabbits.</p><p><b>METHODS</b>The animal mode of ICH was established by perfusing artificial cerebrospinal fluids (aCSF) with controlled pressure into the cerebral ventricles of rabbits. The mean arterial pressure, respiratory rate, tidal volume, perfusion rate of aCSF and water content of cerebrum were investigated in rabbits with ICH after a single bolus of 20% mannitol (5 ml/kg), 7.5% HS (2.2 ml/kg) or 23.4% HS (2.2 ml/kg).</p><p><b>RESULTS</b>After the intracranial pressure was elevated from 15 cmH₂O to 75 cmH₂O, the mean arterial pressure was increased and the tidal volume was decreased. After treatment by 20% mannitol, 7.5% HS or 23.4% HS, the increased percentage of mean arterial pressure and the decreased percentage of tidal volume were similar to the changes in control group. However, the perfusion rate of CSF was increased and water content of cerebrum was decreased after treatment by either 20% mannitol or 23.4% HS, but not by 7.5% HS. No different effects were found between 20% mannitol and 23.4% HS.</p><p><b>CONCLUSION</b>With the similar osmotic burden, 20% mannitol is more effective in treating ICH than 7.5% HS. With higher osmotic load, the efficacy of HS is enhanced, and 23.4% HS may be used as an alternative to mannitol in treatment of ICH.</p>

The expression and significance of signal regulatory protein a1 in autoimmune hepatitis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To observe the expression change of signal regulatory protein alpha1 (SIRPalpha1) in autoimmune hepatitis (AIH) and approach the relationship between SIRPalpha1 and the extent of inflammation.</p><p><b>METHODS</b>Immunohistochemistry is used to detect the expression of SIRPalpha1 in the paraffin section preparations of 33 AIH and 10 normal hepatic tissue.</p><p><b>RESULTS</b>SIRPalpha1 is positive or weakly positive expressed in AIH. The staining is localized in the cytoplasm of Kupffer cells in the hepatic sinusoid with focal distribution. It is negative in normal hepatic tissue. In light AIH, it is negative or weakly positive expressed with a 36.4 percent of the positive rate (4/11). The positive or strong positive expression is found in the moderate AIH with an 84.2 percent of the positive rate(16/19). There is statistical significance between both light AIH, moderate AIH and severe AIH (P less than 0.001) and moderate AIH and light AIH (P less than 0.001). There is no statistical significance between both light AIH and severe AIH (P = 0.145 ) and moderate AIH and severe AIH (P = 0.084).</p><p><b>CONCLUSIONS</b>As a negative regulatory factor, the expression of SIRPalpha1 in hepatic sinusoid Kupffer cells is some associated with the extent of AIH.</p>

Expression and function of autophagy after ischemia/reperfusion in rats hippocampus neuron / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the expression of autophagy after ischemia/reperfusion and its possible function in rats hippocampus neurons.</p><p><b>METHODS</b>After 2 hours oxygen-glucose deprivation and different periods time of reperfusion (OGD/R) treatment in primary hippocampal neurons, neuron viability was evaluated by MTT assay, specific structure of autophagosome and specific protein of autophagy microtubule-associated protein 1 light chain 3 B (LC3B) were detected by transmission electron microscope and immunofluorescence respectively. The inhibitor of autophagy 3-Methyladenine (3-MA) was also used to exam the viability of neurons.</p><p><b>RESULTS</b>Treatment by OGD/R markedly reduced neuronal viability. Compared to the control group, autophagy existed in different time periods after OGD/R shown both in transmission electron microscope and immunofluorescence. Application of 3-MA significantly reduced neuronal viability.</p><p><b>CONCLUSION</b>Oxygen-glucose deprivation can activate autophagy in rat hippocampus neurons, which may resist the injury during ischemia/reperfusion.</p>

Voltage-activated potassium channel blockers inhibit anisodamine-induced relaxation of rabbit aortic smooth muscles precontracted with noradrenaline / 生理学报

Anisodamine, which is originally extracted from scopolia tangutica and is currently produced in China, is a tropane alkaloid and a muscarinic cholinoceptor blocker. Our previous study found that anisodamine did not alter high K(+)-evoked contraction of rabbit aortic rings using isometric tension recording methods, but could attenuate noradrenaline (NA)-, histamine- or 5-hydroxytryptamine-induced contraction in an endothelium-independent manner. Since the high K(+)-elicited depolarization non-selectively inhibits potassium channels in vascular smooth muscle cell (VSMC) membrane, the vasodilation effect of some potassium channel activators may be inhibited or abolished in high K(+) solution. We hypothesized that some potassium channels in VSMC membrane might play a role in the anisodamine-induced relaxation of blood vessels. The present experiment was designed to investigate whether potassium channel blockers inhibit anisodamine-induced relaxation of the rabbit isolated aortic rings. In a 8-min period, 1, 3 and 10 micromol/L of anisodamine, significantly relaxed the 0.01 micromol/L NA precontracted aortic ring by (19.1+/-3.1)%, (30.1+/-3.8)% and (38.3+/-4.2)%, respectively, compared with the controls [by (4.8+/-2.4)%, (5.1+/-1.8)% and (5.6+/-2.5)%, respectively] (P<0.01). 10 mmol/L of CsCl (a non-selective potassium channel blocker), 1 mmol/L of 4-aminopyridine [a selective voltage-activated potassium channel (K(V)) blocker], 10 mumol/L BaCl2 (a selective inwardly-rectifying potassium channel blocker), 10 micromol/L of glibenclamide (a selective ATP-sensitive potassium channel blocker), 3 micromol/L of charybdotoxin (a large- and intermediate-conductance Ca(2+)-activated potassium channels blocker) and 3 micromol/L of apamin (a selective small conductance Ca(2+)-activated potassium channel blocker) significantly increased the NA-induced contraction by (14.4+/-3.2)%, (16.3+/-5.8)%, (12.7+/-4.2)%, (13.6+/-2.0)%, (11.1+/-5.5)% and (13.4+/-4.3)%, respectively, compared with the control [by (5.6 +/-1.2)%] (P<0.01). In the presence of 10 and 30 mmol/L CsCl or 1 and 3 mmol/L 4-aminopyridine, anisodamine-induced relaxation of the 0.01 micromol/L NA contracted rabbit aortic rings [(28.8+/-3.0)% and (15.9+/-3.7)% or (29.7+/-3.9)% and (19.0+/-5.0)%] significantly deceased, compared with that in the absence of any potassium channel blocker [(38.3+/-4.2)% (P<0.01)] in a 8-min period. However, in the presence of 10, 30 micromol/L of BaCl2, 10, 30 micromol/L of glibenclamide, 3 micromol/L of charybdotoxin, or 3 micromol/L apamin, 10 micromol/L anisodamine-induced relaxation [(37.1+/-3.8)%, (36.2+/-4.7)%, (36.1+/-2.7)%, (35.6+/-3.3)%, (37.8+/-2.0)% and (39.3 +/-4.7) %, respectively] did not decrease, compared with the control [(38.3+/-4.2)%] (P>0.05). This study suggests that K(V) blockers inhibit anisodamine-induced relaxation of the rabbit aortic smooth muscle precontracted with NA and implies that the K(V) in VSMC membrane plays a role in anisodamine-induced relaxation of blood vessels.

Study on association of PPP1R3 gene 5 bp deletion/insertion within 3'-untranslated region polymorphism with type 2 diabetes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine whether the muscle-specific glycogen-targeting regulatory subunit of the glucogen bound protein phosphatase 1 (PPP1R3) gene 5 bp deletion/insertion(D/I) within 3'-untranslated region ( 3'-UTR) polymorphism is associated with type 2 diabetes in Chinese Han population in Hefei region of Anhui province.</p><p><b>METHODS</b>The PPP1R3 gene 3'-UTR 5 bp D/I polymorphism was detected by polymerase chain reaction in 268 patients with type 2 diabetes and 106 normal controls.</p><p><b>RESULTS</b>(1) The distributions of the frequency of three genotypes and two alleles of the PPP1R3 gene 5 bp D/I polymorphism showed no significant difference between the type 2 diabetic cases and the normal controls. (2) In both the cases and controls, there was no significant difference in age at onset, duration of disease, blood glucose, blood lipid profile, blood pressure, insulin sensitive index, body mass index, and waist hip ratio between the three genotypic groups(P 0.05). (3) The PPP1R3 gene 3'-UTR polymorphism in Chinese Han population in Hefei region of Anhui province was found to be similar to that in both Japanese population and Canadian population, and to be different from that in Piman Indians and the Caucasians in Sweden.</p><p><b>CONCLUSION</b>The PPP1R3 gene 5 bp D/I within 3'-UTR polymorphism taking on genetic variation among the different races of mankind may not play a critical role in the development of type 2 diabetes mellitus in Chinese Hans of Hefei region in Anhui province.</p>

Study on the association of PPP1R3 gene polymorphism with type 2 diabetes in Han population of Anhui province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the association of muscle-specific glycogen-targeting regulatory subunit of the glucogen-bound protein phosphatase 1 (PPP1R3) gene codon 905 Asp/Tyr polymorphism with type 2 diabetes in Chinese Han population in Hefei region of Anhui province.</p><p><b>METHODS</b>PPP1R3 gene Asp905Tyr polymorphism was detected by polymerase chain reaction and appropriate restriction enzyme (PCR-RFLP) in 262 type 2 diabetic cases and 104 normal controls. Case and control groups were divided into subgroups by body mass index (BMI) 25 kg/m2.</p><p><b>RESULTS</b>When PPP1R3 gene Asp905Tyr polymorphism was not associated with type 2 diabetes mellitus. When subjects with BMI < 25 kg/m2 and Tyr/Tyr genotypes were used as reference. Subjects with Asp905 and BMI > or = 25 kg/m2 had a 3.69-fold increase of risk suffering from type 2 diabetes (OR = 3.69, 95% CI: 1.38-8.89, P=0.006).</p><p><b>CONCLUSIONS</b>PPP1R3 gene Asp905Tyr polymorphism did not seem to play a critical role in the development of type 2 diabetes mellitus in Han population of Chinese in Anhui province but interaction between the Asp905 and BMI cause the increase of risk of type 2 diabetes.</p>

PTEN expression and its significance in human primary hepatocellular carcinoma / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To explore the significance of PTEN (phosphatase and tensin homolog deleted on chromosome 10) in the development of human primary hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>PTEN protein expression in cancerous liver tissues and paired para-carcinoma liver tissues from 60 HCC patients was detected by immunohistochemistry and PTEN mRNA expression was analyzed by northern blot. The significance of PTEN in the development of HCC was analyzed by investigating the relationship between the expression levels of PTEN protein and mRNA, and the clinicopathological parameters of HCC patients.</p><p><b>RESULTS</b>PTEN protein was immunohistochemically stained in the cytoplasmic region of para-carcinoma liver tissues in all the 60 patients, while only 48.3% (29/60) of the patients were positive for PTEN protein in cancerous liver tissues. The positive rate of PTEN protein in HCC tissues were relative to the histological gading and the presence of tumor thrombus. In grade I - II, III, and IV, the positive rates were 84.0%, 23.8%, and 21.4% respectively, and in the group with tumor thrombus was 26.7%, while in the group without tumor thrombus was 55.6%. Northern blot showed that there existed four PTEN mRNA transcripts with the length of 5.5kb, 4.4kb, 2.4kb, and 1.8kb respectively. The level of PTEN mRNA expression in HCC tissues was much lower than that in the paired para-carcinoma liver tissues. The low expression level of the 5.5kb and 4.4kb transcripts was significantly associated with serum AFP value, presence of tumor thrombus, state of satellite lesion and histological grading. The low expression level of the 2.4kb transcript in HCC was significantly associated with the presence of tumor thrombus and satellite lesions in HCC patients. However, no evident relationship between the lowered expression level of the 1.8kb transcript and the clinicopathological parameters of HCC was observed in these 60 patients.</p><p><b>CONCLUSIONS</b>Down-regulation of PTEN expression may play an important role in the development of HCC and the expression level of PTEN may be a potential adjuvant parameter in forecasting the progress and prognosis of HCC.</p>