[Clinical characteristics and prognosis of primary aldosteronism associated with subclinical Cushing syndrome]

Objective: To analyze the clinical characteristics and prognosis of patients with primary aldosteronism (PA) associated with subclinical Cushing syndrome (SCS). Methods: This retrospective cohort study was conducted at the First Affiliated Hospital of Chongqing Medical University in China. Patients with PA were included between January 2014 and December 2022. According to the results of 1-mg overnight dexamethasone suppression test, the patients were divided into the PA group and PA associated with SCS (PA/SCS) group. The demographic information, hormone levels, and follow-up results were analyzed. Independent sample t-test, chi-square test and Mann-Whitney U test were used for data comparison. Results: A total of 489 PA patients were enrolled in this study, of which 109 had PA/SCS (22.3%). Patients with SCS were on average older (54.4±10.7 vs. 47.4±11.0, P<0.001); had a larger proportion of women (69.7%, 76/109 vs. 57.4%, 218/380; P=0.020); and a longer duration of hypertension [96 (36, 180) vs. 60 (12, 120) months, P=0.001] than patients without SCS. There were 215 and 51 patients in the PA group and PA/SCS group, who completed adrenalectomy and follow-up, respectively. The remission rate of autonomous cortisol secretion in the PA/SCS group was 85.3% (29/34). There was no significant difference in the remission rate of autonomous aldosterone secretion among patients between the PA/SCS and PA group (94.1%, 48/51 vs. 94.4%, 203/215; P=1.000), while the clinical remission rate in the PA/SCS group was lower than that in the PA group (39.2%, 20/51 vs. 61.9%, 133/215; P=0.003). Conclusions: SCS is common in PA patients (22.3%), and the clinical remission rate is low. Screening using the 1-mg overnight dexamethasone suppression test is recommended for all patients with PA.

[Study of appropriate cut-off for diagnosis of primary aldosteronism by seated saline suppression test based on liquid chromatography with tandem mass spectrometry]

Objective: To investigate the appropriate cut-off for diagnosis of primary aldosteronism (PA) by seated saline suppression test (SSST) based on liquid chromatography with tandem mass spectrometry (LC-MS/MS). Methods: In this cross-sectional study, patients who underwent SSST for suspected PA in the First Affiliated Hospital of Chongqing Medical University from January 2018 to March 2022 were evaluated. Briefly, 300 patients with PA and 119 with essential hypertension (EH) were included. Plasma aldosterone concentration (PAC) after SSST was determined by LC-MS/MS. Primary aldosteronism confirmatory testing (PACT) score was used as the reference standard for diagnosis of PA, and receiver operating characteristic (ROC) curve was used to explore the cut-off value. Results: The average age of the PA group was (50.8±10.5) years, and males accounted for 53.00% (n=159); the average age of the EH group was (49.4±11.2) years, and males accounted for 26.89% (n=32). The area under the ROC curve of PAC post-SSST was 0.819 (95%CI 0.775-0.862). When 40 pg/ml (110.8 pmol/L) was selected as the appropriate cut-off for diagnosis of PA, the sensitivity was 83.67% (95%CI 78.88%-87.56%) and specificity was 60.50% (95%CI 51.10%-69.21%). Thus, 95.09% (155/163) of patients with unilateral PA could be identified. Conclusion: PAC after SSST determined by LC-MS/MS has high efficacy for diagnosis of PA, and 40 pg/ml is recommended as the appropriate cut-off value.

[Distribution characteristics of plasma renin concentration in patients with aldosterone-producing adenoma]

Objective: To analyze the distribution characteristics of plasma renin concentration (PRC) in patients with aldosterone-producing adenoma (APA) and its impact on diagnosis. Methods: In this retrospective case series, clinical data from 200 patients with APA (80 men and 120 women; mean age 45.6 years) in the First Affiliated Hospital of Chongqing Medical University from November 2013 to January 2022 were evaluated. PRC was determined by automated chemiluminescence immunoassay. The distribution characteristics of PRC were analyzed, and 8.2 mU/L was used as the low renin cutoff to evaluate whether renin was suppressed. Results: The median PRC was 1.6 mU/L (range, 0.4-41.5 mU/L). There were 116 patients with APA with PRC of ≤2 mU/L, 41 patients with 2<PRC≤4 mU/L. PRC was not suppressed (PRC>8.2 mU/L) in 8.0% (16/200) of the patients with APA. And PRC was not suppressed in 2.5% (5/200) of the patients with APA, resulting in a primary aldosteronism negative screening outcome. Conclusions: Although most patients with APA have low PRC, there are a small number (8%) of patients whose PRC has not been fully suppressed, which can lead to missed diagnoses during primary aldosteronism screening. While primary aldosteronism is highly suspected, further investigations are required to determine the diagnosis, even if PRC is not fully suppressed at screening.

[Clinical study on early predictors of concurrent bile duct injury following TACE in patients with liver cancer]

Objective: To explore the predictive factors of concurrent bile duct injury following transcatheter arterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). Methods: A retrospective study was conducted on 483 HCC patients in relation to TACE postoperative complications. A total of 21 cases of bile duct injury were observed following the TACE procedure. Laboratory data, imaging data, and clinically relevant medical histories were recorded before and after one week following the TACE procedure and follow-up. The χ (2) test, or Fisher's exact probability method, was used for categorical variables. The mean of the two samples was compared using a paired t-test or Wilcoxon rank sum test. The comparison of multiple mean values was conducted using an analysis of variance. Results: Twenty-one cases with bile duct injury had intrahepatic bile duct dilatation, bile tumors, hilar biliary duct stenoses, and other manifestations. 14.3% (3/21) of patients showed linear high-density shadows along the bile duct on a plain CT scan, while 76.2% (16/21) of patients had ALP > 200 U/L one week following TACE procedure, and bile duct injury occurred in later follow-up. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and γ-glutamyl transferase (GGT) were significantly increased in all patients following TACE procedure (t = -2.721, P = 0.014; t = -2.674, P = 0.015; t = -3.079, P = 0.006; t = -3.377, P = 0.003, respectively). Conclusion: The deposition of iodized oil around the bile duct on plain CT scan presentation or the continuous increase of ALP (> 200 U/L) one week following TACE procedure has a certain predictive value for the later bile duct injury.

[Establishment and validation of a nomogram-based predictive model for idiopathic aldosteronism]

Objective: To establish and validate a nomogram-based predictive model for idiopathic hyperaldosteronism (IHA). Methods: This cross-sectional study was conducted with the collected clinical and biochemical data of patients with primary aldosteronism (PA) including 249 patients with unilateral primary aldosteronism (UPA) and 107 patients with IHA, who were treated at the Department of Endocrinology of the First Affiliated Hospital of Chongqing Medical University from November 2013 to November 2022. Plasma aldosterone concentration (PAC) and plasma renin concentration (PRC) were measured by chemiluminescence. Stepwise regression analysis was applied to select the key predictors of IHA, and a nomogram-based scoring model was developed. The model was validated in another external independent cohort of patients with PA including 62 patients with UPA and 43 patients with IHA, who were diagnosed at the Department of Endocrinology, First Affiliated Hospital of Zhengzhou University. An independent-sample t test, Mann-Whitney U test, and χ² test were used for statistical analysis. Results: In the training cohort, in comparison with the UPA group, the IHA group showed a higher serum potassium level [M(Q₁, Q₃), 3.4 (3.1, 3.8) mmol/L vs. 2.7 (2.1, 3.1) mmol/L] and higher PRC [4.0 (2.1, 8.2) mU/L vs. 1.5 (0.6, 3.4) mU/L] and a lower PAC post-saline infusion test (SIT) [305 (222, 416) pmol/L vs. 720 (443, 1 136) pmol/L] and a lower rate of unilateral adrenal nodules [33.6% (36/107) vs. 81.1% (202/249)]; the intergroup differences in these measurements were statistically significant (all P<0.001). Serum potassium level, PRC, PAC post-SIT, and the rate of unilateral adrenal nodules showed similar performance in the IHA group in the validation cohort. After stepwise regression analysis for all significant variables in the training cohort, a scoring model based on a nomogram was constructed, and the predictive parameters included the rate of unilateral adrenal nodules, serum potassium concentration, PAC post-SIT, and PRC in the standing position. When the total score was ≥14, the model showed a sensitivity of 0.65 and specificity of 0.90 in the training cohort and a sensitivity of 0.56 and specificity of 1.00 in the validation cohort. Conclusion: The nomogram was used to successfully develop a model for prediction of IHA that could facilitate selection of patients with IHA who required medication directly.

[Application of multiple post labeling delay time arterial spin labeling imaging in the quantitative blood flow analysis of brain subregions in healthy adults]

Objective: To explore the normal ranges of perfusion parameters between cerebral hemisphere, cerebellar hemisphere and brain anatomical subregions (56 pairs) in different gender and age groups with multiple post labeling delay time (Multi-PLD) arterial spin labeling (ASL) imaging. Methods: From November 2020 to December 2020, 42 healthy adult volunteers (Male 25, Female 17) were recruited to perform 7 PLD ASL imaging, including 21 young adults (15 males and 6 females, aged 23-35 years) and 21 seniors (10 males and 11 females, aged 36-74 years). The data was processed offline by Cereflow software to obtain arterial arrival time (ATT) and corrected cerebral blood flow (CBF) and cerebral blood volume (CBV) perfusion parameters. SimpleITK standardization function was used to standardize the calculated perfusion image according to the anatomical automatic labeling (AAL) template. Therefore, CBF, ATT, CBV perfusion values of brain subregions were obtained. Paired samples t test, Wilcoxon rank sum test, independent samples t test and Mann-Whitney U test were used to compare the differences of perfusion parameters in the cerebral hemisphere, the cerebellar hemisphere, brain subregions depending on side, gender and age. Pearson correlation analysis was used to compare the correlations of perfusion parameters with age. Results: CBF in 62.5% (35/56) subregions and CBV in 44.6% (25/56) subregions were higher in right side than those in left side. ATT in most brain anatomical subregions (16/56) were higher in left side. The CBF [(35.30±8.31) vs. (34.34±7.53) ml·100g^-1·min^-1, P=0.021], CBV [(0.47±0.11) vs. (0.45±0.09) ml/100g, P<0.001], ATT [(1.30±0.10) vs. (1.24±0.11) s, P<0.001] in left cerebellar hemisphere were higher than that of right side. The CBF (28/56) of cerebral hemisphere, cerebellar hemisphere and brain subregions was higher in females than that in males, while ATT in 83.9% (47/56) subregions was lower than that in males (all P<0.05). CBV in female subjects was higher only in 5 brain regions (superior occipital gyrus, middle occipital gyrus, inferior occipital gyrus, superior parietal gyrus and cerebelum_7b) (all P<0.05). In young subjects, CBF in 44.6% (25/56) subregions and CBV in 33.9% (19/56) subregions were higher than those in the senior group (all P<0.05). The ATT in most subregions in young group were lower than those in senior group, but the difference was statistically significant only in rectus gyrus (P=0.026) and paracentral lobule (P=0.006). The CBF (r=-0.430, P=0.005) and CBV (r=-0.327, P=0.035) of cerebral hemisphere were negatively correlated with age. The CBF (24/25, r range:-0.497 --0.343, all P<0.05) and CBV (16/19, r range:-0.474 --0.322, all P<0.05) in most subregions were negatively correlated with age, while ATT was positively correlated (gyrus rectus: r=0.311, P=0.045; paracentral lobule: r=0.392, P=0.010). Conclusions: Multi-PLD ASL imaging could be applied for quantitative analysis of brain perfusion. The perfusion parameters of anatomical subregions are different depending on side, gender, and age.

[Re-evaluation of the diagnostic value and optimal cutoff point of captopril challenge test in diagnosis of primary aldosteronism]

Objective: The aim of the present study was to re-evaluate the diagnostic value and optimal cutoff point of captopril challenge test (CCT) in diagnosis of primary aldosteronism (PA). Methods: This is a retrospective study. All patients with a high risk for PA underwent screening test, and then proceeded to CCT and fludrocortisone suppression test (FST) on different days. The FST was used as a reference standard for PA. The plasma renin concentration (PRC) and plasma aldosterone concentration (PAC) were measured with an automated chemiluminescence immunoassay. Random number method was performed in the patients with unilateral primary aldosteronism (UPA), in order to make the proportion of the analyzed UPA in PA was 35%. Receiver operating characteristic (ROC) analyses were performed to compare diagnostic accuracy. Results: A total of 543 patients with 400 PA patients and 143 essential hypertension (EH) patients were enrolled. The diagnostic value of post-CCT PAC was significantly higher than that of the post-CCT plasma aldosterone-renin ratio (ARR), and that of the PAC suppression percentage, respectively. The area under the ROC curve (AUC_ROC) was 0.86 (0.83, 0.89) for PAC, 0.78 (0.74, 0.82) for ARR, and 0.62 (0.56, 0.67) for the PAC suppression percentage (all P<0.01), respectively. The optimal cutoff point of post-CCT PAC for PA was 110 ng/L, in which the sensitivity and specificity were 73.25% and 79.02%, respectively. The diagnostic efficiency of post-CCT PAC was not improved either in combination with PAC suppression percentage or in combination with post-CCT ARR. Conclusions: CCT is a useful test for the confirmation of PA. PAC level of 110 ng/L at 2 h after 50 mg of captopril is recommended as an optimal cutoff point for the diagnosis of PA.

What Factors Lead to Racial Disparities in Outcomes After Total Knee Arthroplasty?

Total knee arthroplasty (TKA) is one of the most commonly performed, major elective surgeries in the USA. African American TKA patients on average experience worse clinical outcomes than whites, including lower improvements in patient-reported outcomes and higher rates of complications, hospital readmissions, and reoperations. The mechanisms leading to these racial health disparities are unclear, but likely involve patient, provider, healthcare system, and societal factors. Lower physical and mental health at baseline, lower social support, provider bias, lower rates of health insurance coverage, higher utilization of lower quality hospitals, and systemic racism may contribute to the inferior outcomes that African Americans experience. Limited evidence suggests that improving the quality of surgical care can offset these factors and lead to a reduction in outcome disparities.

[Adherence to adjuvant with therapy imatinib in patients with gastrointestinal stromal tumor: a national multi-center cross-sectional study]

Objective: To analyze the current adherence to imatinib in patients with gastrointestinal stromal tumors (GIST) in China and its influencing factors. Methods: A cross-sectional survey was conducted. Study period: from October 1, 2020 to November 31, 2020. Study subjects: GIST patients taking imatinib who were diagnosed and treated in public tertiary level A general hospitals or oncology hospitals; those who had not been pathologically diagnosed, those who never received imatinib, or those who had taken imatinib in the past but stopped afterwards were excluded. The Questionnaire Star online surgery platform was used to design a questionnaire about the adherence to adjuvant imatinib therapy of Chinese GIST patients. The link of questionnaire was sent through WeChat. The questionnaire contained basic information of patients, medication status and Morisky Medication Adherence Scale. Results: A total of 2162 questionnaires from 31 provinces, autonomous regions, and municipalities were collected, of which 2005 were valid questionnaires, with an effective rate of 92.7%. The survey subjects included 1104 males and 901 females, with a median age of 56 (22-91) years old. Working status: 609 cases (30.4%) in the work unit, 729 cases (36.4%) of retirement, 667 cases of flexible employment or unemployment (33.3%). Education level: 477 cases (23.8%) with bachelor degree or above, 658 cases (32.8%) of high school, 782 cases (39.0%) of elementary or junior high school, 88 cases (4.4%) without education. Marital status: 1789 cases (89.2%) were married, 179 cases (8.9%) divorced or widowed, 37 cases (1.8%) unmarried. Two hundred and ninety-four patients (14.7%) had metastasis when they were first diagnosed, including 203 liver metastases, 52 peritoneal metastases, and 39 other metastases. One thousand eight hundred and sixty-nine patients underwent surgical treatment, of whom 1642 (81.9%) achieved complete resection. The median time of taking imatinib was 25 (1-200) months. Common adverse reactions of imatinib included 1701 cases (84.8%) of periorbital edema, 1031 cases (51.4%) of leukopenia, 948 cases (47.3%) of fatigue, 781 cases (39.0%) of nausea and vomiting, 709 cases (35.4%) of rash, and 670 cases (33.4%) of lower extremity edema. The score of the Morisky Medication Adherence Scale showed that 392 cases (19.6%) had poor adherence, 1023 cases (51.0%) had moderate adherence, and 590 cases (29.4%) had good adherence. Univariate analysis showed that gender, age, work status, economic income, residence, education level, marriage, the duration of taking medication and adverse reactions were associated with adherence to adjuvant imatinib therapy (all P<0.05). Multivariate analysis showed that female (OR=1.264, P=0.009), non-retirement (OR=1.454, P=0.001), monthly income ≤4000 yuan (OR=1.280, P=0.036), township residents (OR=1.332, P=0.005), unmarried or divorced or widowed (OR=1.362, P=0.026), the duration of imatinib medication >36 months (OR=1.478, P<0.001) and adverse reactions (OR=1.719, P=0.048) were independent risk factors for poor adherence to adjuvant imatinib. Among patients undergoing complete resection, 324 (19.7%) had poor adherence, 836 (50.9%) had moderate adherence, and 482 (29.4%) had good adherence. Meanwhile, 55 patients with good adherence (11.4%) developed recurrence after surgery, 121 patients with moderate adherence (14.5%) developed recurrence, 61 patients with poor adherence (18.8%) developed recurrence, and the difference was statistically significant (P=0.017). Conclusions: The adherence to adjuvant therapy with imatinib in Chinese GIST patients is relatively poor. Females, non-retirement, monthly income ≤4000 yuan, township residents, unmarried or divorced or widowed, the duration of imatinib medication >36 months, and adverse reactions are independently associated with poor adherence of GIST patients. Those with poor adherence have a higher risk of recurrence after surgery. Positive interventions based on the above risk factors are advocated to improve the prognosis of patients with GIST.

[Prevalence and clinical characteristics of obstructive sleep apnea in patients with primary hyperaldosteronism]

Objective: To explore the proportion of obstructive sleep apnea (OSA) in primary aldosteronism (PA) in Chinese population and compare the clinical characteristics between PA patients with OSA and those without. Methods: A total of 96 patients diagnosed with PA from September 2015 to November 2018 were recruited in this study. OSA was screened by cardio-respiratory polygraphy. According to the apnea hypopnea index (AHI), the patients were divided into PA with OSA group (AHI ≥5 times) and PA without OSA group (AHI<5 times). Results: Among all patients (96), 69 (71.9%) were with OSA, among them 22 patients (22.9%) were with mild OSA, 17 patients (17.7%) were with moderate OSA and 30 patients (31.3%) were with severe OSA. Compared with the patients without OSA, the patients with OSA were elder, and had higher levels of body mass index (BMI), waist circumference (WC), hip circumference (HC), creatinine (CR) and glycosylated haemoglobin (HbA1c) (P<0.05), but lower concentrations of plasma aldosterone (PAC), supine aldosterone renin concentration ratio(ARR) and the PAC after the diagnosis test (P<0.05). Spearman correlation analyses showed that BMI, WC, HC, CR and HbA1c were positively correlated with AHI (P<0.05), while high-density lipoproteincholesterol (HDL-C), supine-PAC and saline infusion test(SIT)-post PAC were negatively correlated with AHI (P<0.05). Conclusions: The proportion of OSA in PA patients is relatively high (71.9%). Metabolic abnormalities are more common in PA patients with OSA, indicating that screening for OSA should be carried out routinely in PA patients.

High-performance ceramic/epoxy composite adhesives enabled by rational ceramic bandgaps

High over-all properties, including low dielectric loss, high breakdown strength, high mechanical shock strength, high thermal conductivity and high weight stability, are very difficult to simultaneously achieve in electrical-insulation applicable cured potting-adhesive materials. To deal with this challenge, in this work, we have designed and fabricated a series of epoxy based composite potting-adhesives filled with low-cost and high-performance inorganic micro-particles including alpha-silica, alpha-alumina and alpha-SiC. Combination employment of high-molecular-weight and low-molecular-weight epoxy resins as matrices has been made. Heat-induced curing or crosslink of resin matrices has been carried out. Large band gap of silica filler has endowed the cured composite with high breakdown strength and ageing breakdown strength, and meanwhile relatively high deformation trait of silica has led to high shock strength of cured composite. Silica filler has been found to be superior to other two fillers, namely, optimal over-all properties such as dielectric, breakdown, mechanical and thermal features have been obtained in silica filled cured composite. High breakdown strength of ~48 MV m⁻¹ and shock strength of ~9950 J m⁻² have been achieved in silica loaded composite. This work might open up the way for large-scale fabrication of promising epoxy-based hybrid potting-adhesives.

Cardiovascular tissue bioprinting: Physical and chemical processes

Three-dimensional (3D) cardiac tissue bioprinting occupies a critical crossroads position between the fields of materials engineering, cardiovascular biology, 3D printing, and rational organ replacement design. This complex area of research therefore requires expertise from all those disciplines and it poses some unique considerations that must be accounted for. One of the chief hurdles is that there is a relatively limited systematic organization of the physical and chemical characteristics of bioinks that would make them applicable to cardiac bioprinting. This is of great significance, as heart tissue is functionally complex and the in vivo extracellular niche is under stringent controls with little room for variability before a cardiomyopathy manifests. This review explores the critical parameters that are necessary for biologically relevant bioinks to successfully be leveraged for functional cardiac tissue engineering, which can have applications in in vitro heart tissue models, cardiotoxicity studies, and implantable constructs that can be used to treat a range of cardiomyopathies, or in regenerative medicine.

An automated (novel) algorithm for estimating green vegetation cover fraction from digital image: UIP-MGMEP

Green vegetation cover fraction (VCF) is an important indicator of vegetation status in ecology and agronomy. Digital image analysis (DIA) has been widely accepted as a new VCF measurement technique. In this study, we present a novel fully automatic threshold segmentation algorithm for VCF measurements, which is named as upper inflection point plus mean gradient magnitude of edge pixels (UIP-MGMEP). The algorithm performs VCF estimation upon the vegetation index Excess Green (EXG). UIP-MGMEP optimizes the EXG threshold by searching the upper inflection point (UIP) of the M-Et curve (mean gradient magnitude of edge pixels (MGMEP) vs. EXG threshold), based on the assumption that EXG variance of the boundary pixels between vegetation and background is larger than the variance of the background. Five typical sample images are used to illustrate how ground complexity reduces the distinctness of the UIP. Three controlled experiments are illustrated to test the robustness of UIP-MGMEP to resolution, exposure, and ground complexity. The results show that UIP-MGMEP is a promising algorithm for automatic VCF estimation upon digital images. Compared to broad-leaved grass, narrow-leaved grass is more sensitive to resolution and exposure. To reduce ground complexity, smaller footprint size while more images to cover the same area may be better than one image with large footprint size. UIP-MGMEP is fully automatic, making it promising for batch processing of VCF measurements that is very difficult in any wide-range field survey in the past. UIP-MGMEP algorithm can only extract green vegetation and is not suitable for non-green (even grayish-green) vegetation, due to the limits of vegetation index EXG. In addition, UIP-MGMEP is not recommended for images with VCF less than 0.5% or greater than 99.5%.

Bioengineering cardiac constructs using 3D printing

To date, 3D bioprinting has found many actual and potential applications in medicine through assembling cells, biomaterials and supporting factors into living tissues. In particular, the combination of bioprinting and tissue engineering has emerged as a new promising strategy to address the growing need for tissues and organs for both transplantation and basic research. This review summarizes the current progress in the design and printing of bioengineered cardiac tissues for various applications. We highlight the specific biological and technical complexities such as the choice of cells and biomaterials, cell viability and function, vasculature design and tissue architecture. Current challenges and future perspectives in the field of cardiovascular tissue printing are also discussed.

Not all side effects associated with tricyclic antidepressant therapy are true side effects

BACKGROUND & AIMS

Patients with functional gastrointestinal disorders treated with tricyclic antidepressants sometimes report nongastrointestinal symptoms; it is unclear whether these are drug side effects or reflect a behavioral tendency to report symptoms. We evaluated whether symptoms reported before treatment with a tricyclic antidepressant (desipramine) increased in number or worsened in severity after 2 weeks of treatment and assessed the baseline factors that predispose patients to report symptoms.

METHODS

Female patients in a multicenter National Institutes of Health trial for functional bowel disorders completed a 15-item symptom questionnaire at baseline (before randomization), 2 weeks after they were given desipramine (n = 81) or placebo (n = 40), and at study completion (12 weeks). Patients were asked about the severity and frequency of 15 symptoms. Results were analyzed from 57 patients given desipramine who completed the questionnaires.

RESULTS

Symptoms reported as side effects to have occurred more frequently and also worsened at week 2 in the group given desipramine included dizziness, dry mouth/thirstiness, lightheadedness, jittery feelings/tremors, and flushing. Symptoms that did not change in severity or showed improvement at week 2 in the group given desipramine included morning tiredness, nausea, blurred vision, headaches, appetite reduction, and trouble sleeping. Psychologic distress but not desipramine blood level correlated with symptom reporting.

CONCLUSIONS

Most symptoms often attributed to side effects of desipramine were present before treatment; only a few, related to anticholinergic effects, worsened 2 weeks after treatment, suggesting that most so-called side effects were not associated specifically with desipramine use. Such symptoms might instead be associated with psychologic distress.

Histological observations of morphogenesis in petiole derived callus of Amorphophallus rivieri Durieu in vitro

The initiation and development of somatic embryos and organogenic shoots and corm-like structures (CLSs) from petiole-derived calli of Amorphophallus rivieri Durieu were observed histologically. The petioles were cultured on Murashige and Skoog (MS) medium supplemented with 5.37 microM alpha-naphthaleneacetic acid (NAA) and 4.44 microM N(6)-benzylaminopurine (6-BA) for callus induction. The shoot and corm organogenesis occurred from the compact calli when they were transferred to a medium containing 0.54 microM NAA and 4.44 microM 6-BA. A combination of 13.57 microM 2,4-dichlorophenoxyacetic acid (2,4-D) and 8.88 microM 6-BA or 24.18 microM NAA and 6.66 microM 6-BA was optimum for induction of somatic embryos, which failed to produce plantlets because of their structural abnormalities. Shoot regeneration predominantly happened through organogenesis although somatic embryogenesis infrequently occurred. The subepidermal cells of the compact callus converted to competent cells and started divisions, which resulted in formation of the meristemoids. The meristemoid cells continued division to develop into bud primordia. Subepidermal cells could also form the globular structures. Subsequently, these globoids developed into CLSs from which plantlets regenerated during subculture. Meanwhile, the CLSs were capable to form cormels, which could be a promising way for the propagation of A. rivieri.

[Electrochemical behavior of ofloxacin at Pt/GC ion implantation modified electrode and its application]

AIM

To study the electrochemical behavior of ofloxacin at Pt/GC ion implantation modified electrode.

METHODS

With Pt/GC ion implantation modified electrode as working electrode, the behavior of ofloxacin was studied by voltammetry in 0.40 mol.L-1 KCl solution.

RESULTS

A sensitive reductive peak of ofloxacin was obtained by linear sweep voltammetry. The peak potential was -1.35 V (vs SCE). The peak current was proportional to the concentration of ofloxacin over the range of 1.0 x 10(-6)-3.0 x 10(-5) mol.L-1 with the detection limit of 5.0 x 10(-7) mol.L-1. The behavior of reduction wave was studied and applied to determination of ofloxacin in tablets.

CONCLUSION

The reduction process was irreversible. The element composition, atomicity form and depth of distribution at the surface of Pt/GC electrode were determined by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). The catalysis behavior and reaction mechanism at Pt/GC modified electrode was also studied.

[Species and distribution of medicinal plant Hypericum in Guizhou]

OBJECTIVE

To gain a clear idea on the resources of medicinal plant Hypericum in Guizhou.

METHOD

Conducting field investigation and consulting related specimens and data.

RESULT

The distribution, growing environment and medicinal parts of 18 species of Hypericun have been clarified, and a key for their identification is given.

CONCLUSION

A scientific basis for further study of the medicinal plant Hypericum in Guizhou Province has been provided.

[Studies on the voltammetric behaviour of barbaloin and its application]

In 0.1 mol.L-1 H2SO4 solution, a well-defined reduction wave of barbaloin was obtained by single-sweep osciflopolarography. The peak potential was shown to be -0.75 V (vs SCE). The peak current is proportional to the concentration of barbaloin over the range of 2.0 x 10(-7)-6.0 x 10(-6) mol.L-1. The detection limit is 2.0 x 10(-7) mol.L-1. The voltammetric behaviour of the system was studied by linear sweep and cyclic voltammetry. The adsorption coefficient beta was 1.91 x 10(5). The interaction factor alpha was 1.12. The system is a reversible adsorption wave.

[Binding of acid mucopolysaccharides of Stichopus japanicus to washed human platelets]

The binding of acid mucopolysaccharides of Stichopus japonicus Selenka (Sjamp) to washed human platelets was studied using [3H]Sjamp. The binding was rapid, reversible and with a saturable tendency. The binding reached to equilibrium at about 10 min, and 50% of [3H]Sjamp bound to the platelets at equilibrium within the first minute. When excess unlabeled Sjamp was added to the [3H]Sjamp binding suspension, [3H]Sjamp dissociated from the platelets rapidly and rather completely. Scatchard analysis revealed a class of binding sites with Kd = 2.3 +/- 0.7 micrograms/ml and Bmax = 4.5 +/- 1.2 micrograms/10(9) platelets. Separate experiments showed that the monoclonal antibody (McAb) SZ-21, a McAb to platelet membrane glycoprotein (GP) IIIa, weakened the binding, while McAb SZ-2 and SZ-22 (to GP Ib and GP IIb respectively) were ineffective. We also observed that heparin inhibited [3H]Sjamp binding to the platelets. These results indicated that the binding sites on platelets might be the Sjamp receptors. We conclude that receptor-Sjamp binding is an important process in platelet aggregation induced by Sjamp.