Neuroprotective effect of salidroside on hippocampal neurons in diabetic mice via PI3K/Akt/GSK-3β signaling pathway

BACKGROUND

Diabetic encephalopathy is manifested by cognitive dysfunction. Salidroside, a nature compound isolated from Rhodiola rosea L, has the effects of anti-inflammatory and antioxidant, hypoglycemic and lipid-lowering, improving insulin resistance, inhibiting cell apoptosis, and protecting neurons. However, the mechanism by which salidroside alleviates neuronal degeneration and improves learning and memory impairment in diabetic mice remains unclear.

OBJECTIVE

To investigate the effects and mechanisms of salidroside on hippocampal neurons in streptozotocin-induced diabetic mice.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into 4 groups to receive either sham (control group (CON)), diabetes mellitus (diabetes group (DM)), diabetes mellitus + salidroside (salidroside group (DM + SAL)), and diabetes mellitus + salidroside + phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (diabetes mellitus + salidroside + LY294002 group (DM + SAL + LY294002)). After 12 weeks of diabetes onset, the cognitive behaviors were tested using Morris water maze. The number of hippocampal neurons was detected by Nissl staining. The expressions of PI3K, p-PI3K, Akt, p-Akt, GSK-3β, p-GSK-3β, cleaved caspase-3, caspase-3, Bax, Bcl-2, MAP2, and SYN in the hippocampus were detected by Western blot. Moreover, the expression of MAP2 and SYN in the hippocampus was further confirmed by immunofluorescence staining.

RESULTS

Salidroside increased the time of diabetic mice in the platform quadrant and reduced the escape latency of diabetic mice. Salidroside also increased the expression of p-PI3K, p-Akt, p-GSK-3β, MAP2, SYN, Bcl-2, while suppressed the expression of cleaved caspase-3, caspase3, and Bax in the DM + SAL group compared with the DM group (P < 0.05). The Nissl staining showed that the number of hippocampus neurons in the DM + SAL group was increased with the intact, compact, and regular arrangement, compared with the DM groups (P < 0.05). Interestingly, the protective effects of salidroside on diabetic cognitive dysfunction, hippocampal morphological alterations, and protein expressions were abolished by inhibition of PI3K with LY294002.

CONCLUSIONS

Salidroside exerts neuroprotective properties in diabetic cognitive dysfunction partly via activating the PI3K/Akt/GSK-3β signaling pathway.

[Clinical effectiveness of super pulsed carbon dioxide fractional laser debridement surgery in treating chronic wounds]

Objective: To investigate the clinical effectiveness of super pulsed carbon dioxide fractional laser debridement surgery on the treatment of chronic wounds. Methods: From December 2018 to May 2019, 37 patients with chronic wounds who met the inclusion criteria were admitted to the Affiliated Hospital of Southwest Medical University for a prospective randomized controlled study. Using the random number table, the patients were divided into surgical debridement group (19 patients, 4 males and 15 females, aged (58±16) years, 25 wounds) and laser debridement group (18 patients, 9 males and 9 females, aged (58±10) years, 23 wounds). In patients of surgical debridement group, oedematous and aging granulation tissue was scraped from the wound by scalpel handle or curet, and the residual necrotic tissue was removed by sharp surgical instruments. In patients of laser debridement group, oedematous and aging granulation tissue and necrotic tissue was removed by super pulsed carbon dioxide fractional laser therapeutic machine, laser gasification debridement was performed repeatedly till fresh normal tissue layer observed. In patients of the two groups, according to the wound in the first 3 d after the first debridement, debridement dressing was performed twice at least as before, then wound debridement dressing was performed once every 1 to 4 days as before according to the wound conditions. The wound healing rates on 7, 14, 21, and 28 d after the first debridement were calculated. The positive rates of bacterial culture of wounds before and after the first debridement were calculated. The color and texture of the wound granulation tissue before the first debridement and on 7, 14, and 28 d after the first debridement were observed and scored. The pain scores before every debridement, during every debridement, and after every debridement dressing change were evaluated by visual analogue scale. The times of debridement dressing change were recorded. Data were statistically analyzed with two independent sample t test, analysis of variance for repeated measurement, Fisher's exact probability test, Mann-Whitney U test, and Bonferroni correction. Results: (1) On 7, 14, 21, and 28 d after the first debridement, the wound healing rates of patients in laser debridement group (29.5% (24.1%, 36.0%), 47.1% (42.7%, 62.4%), 71.4% (62.2%, 76.8%), and 88.6% (79.2%, 96.3%) were significantly higher than those of surgical debridement group (1.6% (1.0%, 12.8%), 12.7% (2.0%, 16.6%), 24.5% (8.9%, 45.5%), 43.9% (23.2%, 70.8%), Z=3.477, 3.553, 2.721, 2.193, P<0.05 or P<0.01). (2) Before the first debridement, the positive rates of bacterial culture of wounds in patients of laser debridement group and surgical debridement group were 92% (23/25) and 91% (21/23), respectively, which were similar (P>0.05). After the first debridement, the positive rate of bacterial culture of wounds of patients in surgical debridement group was 64% (16/25), which was significantly higher than 13% (3/23) of laser debridement group (P<0.01). (3) On 7, 14, and 28 d after the first debridement, the scores of color and texture of wound granulation tissue of patients in laser debridement group were significantly higher than those of surgical debridement group (Z=3.420, 5.682, 6.142, 4.461, 5.337, 4.458, P<0.01). (4) The pain scores during every debridement and after every debridement dressing change in patients of laser debridement group were significantly lower than those of surgical debridement group (t=2.847, 5.046, P<0.05 or P<0.01). (5) The time of debridement dressing change in laser debridement group was 8.0 (7.0, 10.0) times, which was significantly less than 10.0 (9.5, 12.5) times in surgical debridement group (Z=2.261, P<0.05). Conclusions: Compared with traditional surgical debridement method, super pulsed carbon dioxide fractional laser debridement surgery is more effective in treating patients with chronic wounds. Laser debridement makes the wound healing more efficiently with reduced pain and better infection control; significantly reduces the number of dressing changes, and is especially suitable for the wound treatment in outpatients.

[A preliminary observation of implanting a double-eyelet capsular tension ring in eyes with serious lens subluxation]

Objective: To evaluate the clinical efficiency of an iris hook combined with a modified double-eyelet capsular tension ring (MCTR) in the treatment of serious lens subluxation. Methods: Retrospective case series. A total of 16 patients (20 eyes) with serious lens subluxation were enrolled in Zhongshan Ophthalmic Center from March 2016 to December 2016. All the patients had an iris hook inserted to support the capsule during the phacoemulsification. Then an MCTR was implanted and sutured onto the sclera. Both intraoperative and postoperative complications, such as posterior capsular opacification and macular edema, were recorded. The postoperative examinations included visual acuity, intraocular pressure, slit-lamp examination, and Pentacam for evaluation of the positions of the capsule and the intraocular lens(IOL). The best corrected visual acuities before and after operation were compared with the matched t test. Results: There were 11 males(12 eyes) and 5 females (8 eyes) among the 16 patients (20 eyes) aged (36±16) years, including 5 cases of Marfan's syndrome (7 eyes), spontaneous ectopia lentis in 7 patients (9 eyes), and traumatic lens dislocation in 4 patients (4 eyes). All the MCTRs were successfully implanted into the capsule. The best corrected visual acuity ranged from 0.3 to 1.0, with 0.5 or higher accounting for 90% (18 eyes). It was 0.20±0.14 and 0.21±0.13, respectively, at 3 and 6 months, which was significantly better than the preoperative best corrected visual acuity (logarithm of the minimal angle of resolution) (0.74±0.51;t=5.302, P<0.001; t=5.131;P<0.001). One eye had macular edema 3 months after surgery, and then was treated by conservative management. Two eyes(2 case) developed mild posterior capsular opacification 6 months after operation. No intraocular hypertension was persistently observed. All IOLs and capsular bags were in the expected position without an obvious tilt or displacement. Conclusion: The surgical strategy of iris hooks combined with MCTRs in the treatment of serious lens subluxation could maintain long-term stability of the capsule. (Chin J Ophthalmol, 2018, 54: 343-348).

N-terminal Pro-B-type Natriuretic Peptide is Associated with Arterial Stiffness as Measured According to the Brachial-ankle Pulse Wave Velocity in Patients with Takayasu Arteritis

AIM

Takayasu arteritis (TA) is associated with increased cardiovascular morbidity and mortality, and the degree of arterial stiffness is an independent predictor of cardiovascular mortality in a variety of diseases. In addition, the levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), a marker of ventricular dysfunction, have been found to be higher in patients with TA than in healthy controls. In this study, we aimed to investigate the relationship between the plasma NT-proBNP levels and arterial stiffness in patients with TA.

METHODS

Seventy-two patients with TA were recruited in this study. The participants were analyzed with respect to the NT-proBNP levels, cardiovascular risk factors, TA-related variables and arterial stiffness assessed according to the brachial-ankle pulse wave velocity (baPWV). The patients were divided into two groups based on the mean baPWV, and the association between the NT-proBNP and baPWV values was tested using uni- and multivariate analyses.

RESULTS

Twenty-four patients (33.3%) were classified into the high-baPWV group. The body mass index (p=0.035), systolic blood pressure (p＜0.001), diastolic blood pressure (p=0.001), mean blood pressure (p＜0.001), plasma NT-proBNP levels (p=0.036) and total cholesterol levels (p=0.030) were significantly higher in the high-baPWV group than in the low-baPWV group. A stepwise multiple linear regression analysis revealed the mean blood pressure (p＜0.001), age (p=0.002), and NT-proBNP level (p=0.002) to be independent determinants of the ba-PWV after adjusting for other confounding factors.

CONCLUSIONS

The plasma NT-proBNP levels are independently associated with the degree of arterial stiffness measured according to the baPWV in patients with TA.

Construction and functional activity of a recombinant vector expressing rat glutamic acid decarboxylase 65

OBJECTIVE

Glutamic acid decarboxylase 2 (GAD65) is a gamma-aminobutyric acid (GABA) synthetase. This study aimed to construct a recombinant lentivirus-rGAD65 (rLV-rGAD65) vector containing the cDNA of rat GAD65 (rGAD65) and assess its functional activity in vitro and in vivo.

METHODS

cDNA of rGAD65 was amplified by RT-PCR and subcloned into the LV vector, forming the rLV-GFP-rGAD65 plasmid. The recombinant lentivirus particles (rLV-rGAD65) were packaged by the LV Helper-Free System and the titer was measured. Primary rat lung fibroblasts were transfected with rLV-rGAD65. The expression of rGAD65 in fibroblasts was detected by immunocytochemistry and western blot and the level of GABA in the medium was assessed by high-performance liquid chromatograph (HPLC). In vivo, rLV-rGAD65 was injected into the subthalamic nucleus (STN) of Sprague-Dawley rats using stereotaxic methods, and rGAD65 protein levels in the STN were assessed by immunohistochemistry and Western blot, while the GABA concentration in the substantia nigra pars reticulata (SNr) was assayed by HPLC.

RESULTS

The sequence of rGAD65 cDNA was in accord with that in GenBank. The amino-acid sequence of rGAD65 had no mutations and the titer of rLV-rGAD65 reached 6.8 × 10⁸/mL. The efficiency of infection of fibroblasts was 80%, and the concentration of GABA in the medium was (48.14 +/- 9.35) nmol/L. In vivo, rGAD65 expression was detected in the STN, and the concentration of GABA in the SNr increased from (5.95 +/- 1.09) to (12.44 +/- 3.79) nmol/g tissue.

CONCLUSION

The recombinant LV-GFP-rGAD65 vector was successfully constructed. rLV-rGAD65-infected primary fibroblasts in vitro and the expressed rGAD65 catalyzed the formation of GABA from glutamic acid. In vivo, the concentration of GABA in the SNr was increased after rLV-rGAD65 injection into the STN.

[Experimental study on tracheal reconstruction using porous titanium rings and free skin flap]

OBJECTIVE

To investigate the feasibility and efficacy of the cervical tracheal reconstruction using porous titanium rings and free skin flap.

METHODS

Twelve adult mongrel dogs were divided randomly into group I and group lI. A segment of cervical trachea (25 mm, 4 rings, about 2/3 circumference) was resected and a rectangular free skin flap was harvested from abdomen. The flap was sutured to the defect part and supported with two porous titanium rings (group I) or without (group II ). X ray and fiberscopic examinations were performed at the end of the first and the sixth months postoperatively. After six months the dogs were sacrificed and the grafts were examined macroscopically and microscopically.

RESULTS

In group I, one dog was sacrificed for wound infection and skin flap necrosis with deflexion of titanium rings in the fifth day postoperatively. The other 5 of 6 survived until the end of six months. X-ray examination showed titanium rings were fastened well without displacement or deformity. Through fiberscopy, the trachea luminal patency was maintained well without stricture, shrinkage or necrosis. Histologic examination showed most of the inner surface of the flap was covered with ciliated columnar epithelium. In group II, 3 of 6 dogs died of suffocation within 24 hours postoperatively. The remaining 3 dogs survived from 7 to 16 days with dyspnea and fiberscopic examination showed narrowed trachea lumens.

CONCLUSIONS

Porous titanium rings could recreate the framework for cervical tracheal reconstruction using free skin flap and would be one of the options for tracheal reconstruction.

[Diagnostic value of transbronchial lung biopsy via fiberbronchoscope of peripheral or diffuse pulmonary disease]

OBJECTIVE

To understand the diagnostic value of peripheral and diffuse pulmonary disease examined with Transbronchial lung biopsy (TBLB) via fiberoptic bronchoscope.

METHODS

Four hundred and sixty patients of peripheral and diffuse pulmonary disease were diagnosed with TBLB via fiberoptic bronchoscope without fluoroscopic guidance. The result of clinical data and pathologic diagnosis were underwent retrospectively analyses.

RESULTS

Confirmed diagnosis was obtained in 351 patients; the total positive diagnostic rate was 76.3%. Diseases were included lung cancer, pulmonary tuberculosis, diffuse interstitial pulmonary fibrosis, pulmonary sarcoidosis etc. The positive diagnostic rate of TBLB on pleural pulmonary disorders was the lowest. There were no any other serious complications except bleeding, blood sputum, fever and pneumothorax occasionally.

CONCLUSIONS

TBLB in diagnoses of peripheral and diffuse pulmonary disease is a reliable, safe, handy cheap, may repeatable operational method.

Long-term effect of leprosy control in two Prefectures of China, 1955-1993

In Weifang Prefecture, Shandong Province, and Wenshan Prefecture, Yunnan Province of China, leprosy was highly prevalent in the 1950s. Due to differences in geographical conditions and socioeconomic development, the decline in leprosy prevalence between 1955 and 1993 was 99.5% (10.1 to 0.05/10,000) in Weifang and 93.9% (19.7 to 1.2/10,000) in Wenshan. The decrease in the detection rate was 99.9% (35.2 to 0.05/10,000) in Weifang and 91.7% (69.9 to 5.8/10,000) in Wenshan. The decrease was more apparent in these two prefectures since the implementation of multidrug therapy (MDT) in 1986. Findings such as specific detection rates by age, sex and type, as well as the multibacillary, child, and deformity rates of patients detected since 1980 were studied. Using the detection and prevalence rates between 1980 and 1993, the number of patients until the year 2000 is extrapolated for these two prefectures.

[Functional and histological evidence of insulin resistance in spontaneously hypertensive rat]

In order to confirm the existence of insulin resistance in spontaneously hypertensive rat (SHR), rich musculature glucose tolerance test (GTT) and histological method examination of the insulin receptor were carried out in SHR and the normotensives (WKY). The basal serum insulin level was higher and the area under insulin curve during GTT was also higher in SHR than those in WKY, while the basal serum glucose level and the area under glucose curve during GTT in SHR were similar to those in WKY. As compared with WKY, SHR displayed a significantly lower percentage of insulin sensitive slow-twitch fiber of plantaris and medial head of gastrocnemius (type I fiber). There were strong positive correlations between blood pressure (BP) and insulin as well as between BP and the area under insulin curve, but the correlation between insulin and percentage of type I fiber was negative. In conclusion, the present study provides both functional and structural evidence of insulin resistance in SHR.

Effects of atrial natriuretic factor on patients with renovascular hypertension

Previous studies have shown the effects of atrial natriuretic factor (ANF) on rats with renovascular hypertension (RVH). In the present study low dose alpha-hANF (0.025 microgram/kg/min) was administered intravenously for 60 minutes to seven RVH patients. Results demonstrated an inhibition of renin-angiotensin-aldosterone system (RAAS), reduction of plasma catecholamine and arginine vasopressin(AVP), diuresis and natriuresis, increase of hematocrit and creatinine clearance, and slight decrease of blood pressure. These results showed that most factors involved in the establishment and maintenance of RVH are affected by ANF infusion.

Clinical studies in 500 patients with aortoarteritis

Five hundred patients with aortoarteritis were studied in this series. The long-term administration of small dosage of corticosteroid is effective in treating this disease in its active stage. The patients with renal vascular hypertension should be treated by percutaneous transluminal renal angioplasty or by surgery if indicated. About one third of the pulsations of the involved arteries were improved. The incidence of complications was 17% and the mortality rate was 11% in this series. Cerebral thrombosis was found as a common complication and hemorrhage as a common cause of death. Three patients died of heart failure without aortic regurgitation. Five-year and ten-year survival rates were 93.1% and 91.1% respectively.

Comparison of erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity in children with and without family history of essential hypertension

The causes of elevated intra-erythrocyte calcium in the offspring of essential hypertensive patients are unknown. Fourteen children with and without a family history of essential hypertension were chosen to compare erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity (Rbc-M Ca2(+)-Mg2(+)-ATPase activity) measured by biochemical methods. We found that Rbc-M Ca2(+)-Mg2(+)-ATPase activity was lower in children with family history of hypertension compared with children with no family history (2.16 +/- 1.10 vs 3.36 +/- 1.19 microM Pi/mg protein/hour P less than 0.01). These results suggest that the reduced Rbc-M Ca2(+)-Mg2(+)-ATPase activity may be one of the mechanisms causing the high erythrocyte calcium levels in the offspring of essential hypertensive patients.

Aortoarteritis: a report of 480 cases

We report 480 patients with aorto-arteritis studied in our group. Among 320 patients, who were diagnosed by aortography the female to male ratio was 2.8:1, and the age of onset ranged from 5-45 years. The patients were followed for 1-27 years (average 6.8 years). Two hundred and eighty-six (59.6%) patients with renovascular hypertension were found in the group. All patients were treated with medical or surgical procedures. One hundred and thirty patients with renovascular hypertension were operated upon by revascularisation or uninephrectomy and 11 patients with renal artery stenosis were subjected to percutaneous transluminal renal angioplasty. There were 55 deaths (11.5%) in the group, cerebral haemorrhage being the major cause of death. Five year and ten year survival rates were 93.1% and 91.1% respectively.

[Comparison of erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity in children with and without a family history of essential hypertension]

15 children with and without family history of essential hypertension respectively were chosen to compare erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity measured with biochemical method. Results were as follows: erythrocyte membrane Ca2(+)-Mg2(+)-ATPase activity was lower in children with family history of essential hypertension (2.16 +/- 1.10 vs 3.36 +/- 1.19 mumol Pi.mg protein-1/hour, P less than 0.01). This may be the cause of increase of intraerythrocyte calcium in offspring of hypertensive patients.

[Influence of zinc deprivation on thymus, spleen development and adenosine deaminase activity in young rats]

This study on the thymus and spleen development and ADA activity was done in young rats with zinc deprivation and supplementation. The serum zinc level, body weight, absolute and relative weight, and ADA activity of the thymus and spleen were compared between the experimental rats and the control group. Above indications were all decreased; especially both the thymus weight and the thymus ADA activity were markedly decreased in the zinc deficient group. The averages of thymic absolute weight, relative weight and ADA activity were dropped by 61.32%, 54.54% and 47.59%, respectively. After zinc supplementation for one month, all the body weight, weight of the thymus and spleen, and ADA activity of the spleen were recovered to the control group's level, while ADA activity of the thymus was 33.03% higher than that of the control group. Our data suggested that zinc was not only an important trace element in maintaining the growth of the body, the development of the thymus and spleen, but it may be an important agent to activate the ADA or to prompt synthesis of ADA.

[Differences in length and weight growth patterns between urban and rural infants]

Mixed longitudinal data of length and weight growth from 595 rural and 337 urban infants were analysed. Count models were fitted to the means of length and weight in different ages, sexes and feedings separately. The curve fitting to the data was rather satisfactory. Comparison of model parameters between urban and rural infants suggested that rural infants had a higher length level at birth but lower accelerative growth afterwards than urban ones, which was even more obvious in breast-fed infants. The difference in birth weight between them was not significant; and the urban infants had a faster linear growth velocity than rural ones. These results might be caused by the fact that food supplementing in urban infants was significantly earlier and better than in rural ones.

[Aortoarteritis complicated by aortic insufficiency (with an analysis of 10 cases)]

Ten cases of aortic regurgitation in the patients with aortoarteritis in our group were studied during the period 1958-1988. Nine out of 10 patients with aortoarteritis were performed by aortography. The incidence of aortic regurgitation is 2.2 per cent in 450 patients with aortoarteritis. In all the patients with aortic regurgitation diastolic murmurs were heard in the aortic valves. X-ray findings showed dilatation of ascending aorta with aortic regurgitation in 10 patients and enlargement of left ventricle in 7 patients. Subclavian artery and carotid artery were involved in all patients. Descending aorta or abdominal aorta were also involved in 6 of them. Two patients with angina pectoris were studied by coronary arteriography and the coronary arteries were normal. Clinically, these cases should be differentiated from aortic regurgitation of other etiology.

Variability of urinary sodium and potassium excretion in north Chinese men

Variability of urine sodium (Na), potassium (K) and sodium/potassium (Na/K) excretion was studied in a sample of 50 employed normotensive male health professionals aged 27-50 in Beijing, China. Six 24-h urine specimens were collected from each participant during night-time (12-h) and daytime (12-h) fractions. The estimated ratio of intra- to inter-individual variances was 2.12 for night-time and 1.48 for 24-h urine Na, and 1.85 and 1.54, respectively, for urine K. Based on these values, six night-time and four 24-h urine specimens are necessary to reduce to 15% the diminution of a correlation between urine Na and another physiological variable. The corresponding numbers are five and four, respectively, for urinary K measurement. These data suggest that the ratio of within-person variation to between-person variation in Na excretion is smaller in these Chinese men than in Americans. The dietary Na intake of Chinese men can therefore be characterized with fewer urine specimens than are required for western populations. Night-time urinary Na and K showed good concordance with those from 24-h specimens in distinguishing high or low Na and K intake. These findings indicate that in large-scale epidemiological studies, overnight specimens may be adequate for classifying individuals with regard to Na and K intake.