Exercise promotes osteogenic differentiation by activating the long non-coding RNA H19/microRNA-149 axis.

BACKGROUND: Regular physical activity during childhood and adolescence is beneficial to bone development, as evidenced by the ability to increase bone density and peak bone mass by promoting bone formation. AIM: To investigate the effects of exercise on bone formation in growing mice and to investigate the underlying mechanisms. METHODS: 20 growing mice were randomly divided into two groups: Con group (control group, n = 10) and Ex group (treadmill exercise group, n = 10). Hematoxylin-eosin staining, immunohistochemistry, and micro-CT scanning were used to assess the bone formation-related indexes of the mouse femur. Bioinformatics analysis was used to find potential miRNAs targets of long non-coding RNA H19 (lncRNA H19). RT-qPCR and Western Blot were used to confirm potential miRNA target genes of lncRNA H19 and the role of lncRNA H19 in promoting osteogenic differentiation. RESULTS: Compared with the Con group, the expression of bone morphogenetic protein 2 was also significantly increased. The micro-CT results showed that 8 wk moderate-intensity treadmill exercise significantly increased bone mineral density, bone volume fraction, and the number of trabeculae, and decreased trabecular segregation in the femur of mice. Inhibition of lncRNA H19 significantly upregulated the expression of miR-149 and suppressed the expression of markers of osteogenic differentiation. In addition, knockdown of lncRNA H19 significantly downregulated the expression of autophagy markers, which is consistent with the results of autophagy-related protein changes detected in mouse femurs by immunofluorescence. CONCLUSION: Appropriate treadmill exercise can effectively stimulate bone formation and promote the increase of bone density and bone volume in growing mice, thus enhancing the peak bone mass of mice. The lncRNA H19/miR-149 axis plays an important regulatory role in osteogenic differentiation.

BSR and Full-Length Transcriptome Approaches Identified Candidate Genes for High Seed Ratio in Camellia vietnamensis.

(1) Background: C. vietnamensis is very suitable for growth in the low hilly areas of southern subtropical regions. Under appropriate conditions, the oil yield of C. vietnamensis can reach 1125 kg/ha (the existing varieties can reach 750 kg/ha). Moreover, the fruit of C. vietnamensis is large and the pericarp is thick (>5 cm). Therefore, a high seed ratio has become the main target economic trait for the breeding of C. vietnamensis. (2) Methods: A half-sibling population of C. vietnamensis plants with a combination of high and low seed ratios was constructed by crossing a C. vietnamensis female parent. Bulked segregant RNA analysis and full-length transcriptome sequencing were performed to determine the molecular mechanisms underlying a high seed ratio. (3) Results: Seed ratio is a complex quantitative trait with a normal distribution, which is significantly associated with four other traits of fruit (seed weight, seed number, fruit diameter, and pericarp thickness). Two candidate regions related to high seed ratio (HSR) were predicted. One spanned 140.8−148.4 Mb of chromosome 2 and was associated with 97 seed-yield-related candidate genes ranging in length from 278 to 16,628 bp. The other spanned 35.3−37.3 Mb on chromosome 15 and was associated with 38 genes ranging in length from 221 to 16,928 bp. Using the full-length transcript as a template, a total of 115 candidate transcripts were obtained, and 78 transcripts were predicted to be functionally annotated. The DEGs from two set pairs of cDNA sequencing bulks were enriched to cytochrome p450 CYP76F14 (KOG0156; GO:0055114, HSR4, HSR7), the gibberellin phytohormone pathway (GO:0016787, HSR5), the calcium signaling pathway (GO:0005509, HSR6), the polyubiquitin-PPAR signaling pathway (GO:0005515, HSR2, HSR3), and several main transcription factors (bZIP transcription factor, HSR1) in C. vietnamensis.

Relationship between Methylation of FHIT and CDH13 Gene Promoter Region and Liver Cancer.

In order to demonstrate the relationship between methylation of fragile histidine triad (FHIT) and T-cadherin/H-cadherin (CDH13) genes and liver cancer, the methylation status of FHIT and CDH13 was detected in healthy individuals and in Mongolian and Han patients with liver cancer. The phenol-chloroform method was used to extract genomic DNA. The methylation specific polymerase chain reaction method was applied to detect the methylation status of FHIT and CDH13. The relationship between smoking and alcohol consumption and gene (FHIT and CDH13) methylation was analyzed. There was significant difference in methylation rate of FHIT (72.67%, 34.67%) and CDH13 (72.0%, 28.0%) between liver cancer patients and healthy individuals of Mongolian descent (P<0.05), as well as that of FHIT (68%, 30.67%) and CDH13 (64%, 26%) between liver cancer patients and healthy individuals of Han individuals (P<0.05). There was also a relationship between smoking and drinking and the methylation of FHIT and CDH13 (P<0.05). Thus, the methylation of FHIT and CDH13 had a relationship with liver cancer incidence. Smoking and alcohol ingestion may promote the methylation of FHIT and CDH13.

Structural analysis and antioxidant activities of neutral polysaccharide isolated from Epimedium koreanum Nakai.

The structure and antioxidant activity of a neutral polysaccharide (named as EFPN-1) from Epimedium koreanum Nakai were studied. Based on the results from high performance gel permeation chromatography, methylation GC-MS and 1D/2D nuclear magnetic resonance spectroscopy, EFPN-1 was a branched polysaccharide with a molecular weight of 21.9 kD and containing over 60% of glucose. Its backbone was composed of (1 → 4)-ß-d-Glcp and (1 → 3)-ß-d-Galp, branched partially at O-6 of both residues, with a degree of branching of 40.4% and terminated mainly with Ara and Gal, as well as trace amount of Gal. Antioxidant tests showed that EFPN-1 exhibited a strong capacity on DPPH and hydroxyl radical scavenging, ferrous ion chelation and reducing antioxidant powder. EFPN-1 has potential to be developed as a natural antioxidant.

A pro-atherogenic HDL profile in coronary heart disease patients: an iTRAQ labelling-based proteomic approach.

OBJECTIVES: This study aims to compare the protein composition of high-density lipoprotein (HDL) particles in coronary heart disease (CHD) patients and controls by proteomic methods. BACKGROUND: HDL has been reported to exert pro-atherogenic properties in CHD patients. Accumulating evidence indicates that HDL composition, rather than the HDL-C level, determines its functions. The changes in HDL composition involved in the conversion of anti-atherogenic to pro-atherogenic properties in CHD patients are currently unknown. METHODS AND RESULTS: iTRAQ combined with nanoLC-MS/MS was performed to obtain a differential expression profile of the HDL pooled samples of the male age-matched CHD patients and controls (n = 10/group). Of the 196 proteins identified in the examined HDL, 12 were differentially expressed between the CHD patients and the controls, including five up-regulated proteins and seven down-regulated proteins. Using GO analysis, we determined that the up-regulated proteins were mostly involved in inflammatory reactions, displaying a potential pro-atherogenic profile. In contrast, the down-regulated proteins were mostly involved in lipid metabolism processes, displaying anti-atherogenic properties. To confirm the proteomic results, serum amyloid A (SAA) and apoC-I were selected and quantified by ELISA, in the same population as the proteomic analysis, as well as another independent population (n = 120/group). Consistent with the proteomic results, the amount of SAA was significantly increased, and apoC-I was significantly decreased in the HDL particles of CHD patients compared with those of controls (P<0.05). CONCLUSIONS: Our study shows that the HDL proteome changes to a pro-atherogenic profile in CHD patients, which might compromise the protective effects of HDL. Proteomic analysis of HDL composition may provide more relevant information regarding their functional properties than steady-state HDL-C levels.

B-cell activating factor as a serological biomarker for polymyositis and dermatomyositis.

AIM: To investigate serum levels of B-cell activating factor (BAFF) in the patients with polymyositis (PM) and dermatomyositis (DM), and to systematically examine the association between serum BAFF levels and disease activity in PM/DM patients. PATIENTS & METHODS: A cross-sectional analysis included 92 PM/DM patients and 25 healthy control subjects. A longitudinal study followed 24 patients. Serum BAFF concentrations were detected by the ELISA method. RESULTS: Serum BAFF levels in PM/DM patients were significantly higher than those in healthy controls. A cross-sectional assessment revealed a modest correlation between serum BAFF levels and global disease activity and a mild correlation between serum BAFF levels and muscle disease activity. The longitudinal study showed that serum BAFF levels modestly correlated with global disease activity and muscle disease activity. CONCLUSION: Resulting data showed high serum BAFF levels in PM/DM patients and suggested BAFF as a serological biomarker for PM/DM disease activity.

Sophorolipid production from delignined corncob residue by Wickerhamiella domercqiae var. sophorolipid CGMCC 1576 and Cryptococcus curvatus ATCC 96219.

Delignined corncob residue hydrolysate (DCCRH) and detoxified DCCRH were used for single cell oil (SCO) and single cell protein (SCP) production of Cryptococcus curvatus ATCC 96219 and for sophorolipid (SL) production of Wickerhamiella domercqiae var. sophorolipid CGMCC 1576. Both C. curvatus and W. domercqiae could utilize glucose in DCCRH to grow and accumulate lipids or particle-shaped SLs. DCCRH detoxification by activated carbon adsorption not only improved cell growth and lipid accumulation of C. curvatus but also increased SL production and proportion of lactonic SL in total SL. A total biomass of 17.36 g/l with a lipid content of 44.36 % could be achieved after cultivation of C. curvatus on the detoxified DCCRH. The predominant fatty acids of the produced SCO were oleic, stearic, and palmitic acids (27.2, 20.5, and 15.7 %, respectively). When W. domercqiae cells were cultivated on DCCRH and SCO, total SL production of 39.08 g/l (DCCRH + SCO) and 42.06 g/l (detoxified DCCRH + SCO) were obtained. Furthermore, when cell lysate of C. curvatus, oleic acid, and DCCRH/detoxified DCCRH was used as nitrogen and carbon sources, total SL production reached 37.19 g/l and 48.97 g/l, respectively. These results demonstrated that renewable DCCRH can be utilized for the production of high-value SCO and SLs.

The relationship between serum amyloid A and apolipoprotein A-I in high-density lipoprotein isolated from patients with coronary heart disease.

BACKGROUND: Alteration in the protein composition of high-density lipoprotein (HDL) has been proposed as a mechanism for the development of coronary heart disease (CHD). In HDL, an increase in serum amyloid A protein (SAA) accompanying the decrease in apolipoprotein A-I (apoA-I) has been found during the acute inflammation period. However, whether this phenomenon persists in CHD patients, a disease related to inflammation, is unknown. The purpose of the present study was to explore the relationship between SAA and apoA-I in HDL isolated from CHD patients. METHODS: Overall, 98 patients with confirmed stable CHD and 90 control subjects matched for age and gender were enrolled in this case-control study. Potassium bromide (KBr) density gradient ultracentrifugation was used to isolate HDL from plasma. The levels of SAA and apoA-I in the HDL samples were detected by enzyme-linked immunosorbent assay kits. Pearson's correlation and general linear models were used in the analysis. RESULTS: Compared with controls, patients with CHD had a significant decrease in the amount of apoA-I ((14.21 ± 8.44) µg/ml vs. (10.95 ± 5.95) µg/ml, P = 0.003) in HDL and a significant increase in the amount of log SAA (1.21 ± 0.46 vs. 1.51 ± 0.55, P < 0.00001). Differences were independent of age, body mass index (BMI), HDL cholesterol (HDL-C), and other factors. An independently and statistically significant positive correlation between log SAA and apoA-I in HDL was observed only in the CHD group (ß = 2.0, P = 0.026). In the general linear model, changes in log(SAA), age, age2, gender, BMI and HDL-C could explain a statistically significant 43% of the variance in apoA-I. CONCLUSIONS: This study provides direct evidence for the first time that there was an independent positive correlation between log SAA and apoA-I in the HDL of CHD patients, indicating the alteration of protein composition in HDL. However, the question of whether this alteration in HDL is associated with impairment of HDL functions requires further research.

[Surfactant proteins-A and D as important serum markers for interstitial lung disease in patients with polymyositis or dermatomyositis].

OBJECTIVE: To explore the possible diagnostic values of serum surfactant protein-A (SP-A) and surfactant protein-D (SP-D) for interstitial lung diseases (ILD) in patients with polymyositis or dermatomyositis (PM/DM). METHODS: Serum MCP-1 concentrations were measured by enzyme-linked immunosorbent assay (ELISA) in 100 adult PM/DM patients, 20 patients with pulmonary infection and 42 healthy controls. And the association with their clinical features and serum levels of SP-A and SP-D was analyzed. RESULTS: The serum levels of SP-A and SP-D in the PM/DM patients with ILD were both significantly higher than those without ILD and healthy controls (all P < 0.01) while there were no significance differences with those with infectious lung diseases (P > 0.05). The sensitivity of serum abnormal levels of SP-A, SP-D and combination of SP-A and SP-D for ILD in PM/DM patients were 66.1%, 64.3% and 80.0% and the specificity 72.7%, 72.7% and 70.2% respectively. The serum levels of SP-A were positively correlated with serum ferritin and C-reactive protein (CRP) and negatively with percent carbon monoxide diffusing capacity (DLCO%) (r = -0.474, P < 0.05), VC% (r = -0.404, P < 0.05) while the serum levels of SP-D were negatively correlated with circulating CD3+T cells (r = -0.244, P < 0.05) and CD4+T cells (r = -0.277, P < 0.05) in PM/DM patients. Furthermore, SP-A was an independent risk factor for death of ILD in PM/DM (OR 1.032, 95%CI 1.006 - 1.059, P < 0.05). CONCLUSION: SP-A and SP-D may be potential useful serum markers for the diagnosis of ILD in PM/DM patients. And the combined detection of SP-A and SP-D offers a higher sensitivity than either marker alone. As a risk factor, serum SP-A can predict the prognosis of PM/DM patients with ILD.

Clinical significance of peripheral blood lymphocyte subsets in patients with polymyositis and dermatomyositis.

Peripheral blood lymphocyte subsets were determined by flow cytometry in 89 Chinese patients with polymyositis (PM) and dermatomyositis (DM). We aimed to investigate the clinical significance of peripheral blood lymphocyte subsets in PM/DM. Patients with active DM showed significant decreases in numbers of CD3(+) cells, CD3(+)CD4(+) cells, and CD3(+)CD8(+) cells, as compared to patients with inactive DM and healthy controls (P < 0.05). CD3(+) and CD3(+)CD4(+) cell counts were significantly lower in DM before treatment, compared with after treatment (t = -5.714 and -3.665, P < 0.05). Counts of CD3(+) cells, CD3(+)CD4(+) cells, CD3(+)CD8(+) cells, and CD19(+)CD5(-) cells were all correlated with the total disease activity score as determined by the Myositis Disease Activity Assessment Visual Analogue Scale (P < 0.05). The decreased number of CD3(+) cells and the decreased percentage of CD3(+)CD4(+) cells were additionally correlated with the presence of interstitial lung disease in PM/DM (P < 0.05). The presence of levels of CD3(+)CD8(+) cells was risk factor for death (b = -0.011, OR = 0.989, P < 0.05). The identification of peripheral blood T lymphocyte subsets in PM/DM appears to be useful as a reference marker in the evaluation of clinical disease activity, and be useful in the comprehensive assessment of clinical lung involvement. A decrease in CD8(+) T cells may predict a poor outcome in patients with PM/DM.

[Measurement and clinical significance of serum monocyte chemoattractant protein-1 in patients with polymyosits/dermatomyosits].

OBJECTIVE: To analyze the correlated clinical significance by testing the serum monocyte chemoattractant protein-1 (MCP-1) levels of patients with polymyositis/dermatomyositis (PM/DM). METHODS: The sera from 100 adult PM/DM patients, 20 patients with pulmonary infection and 42 healthy controls were selected. The serum MCP-1 concentrations were detected by enzyme-linked immunosorbent assay (ELISA). The correlations between serum MCP-1 levels and clinical features or laboratory examinations of PM/DM patients were investigated. RESULTS: The serum levels of MCP-1 were (1 869 ±1 590) ng/L, (1 349±1 303) ng/L, (493±255) ng/L and (256±144) ng/L in PM/DM patients with interstitial lung disease (ILD) and without ILD, patients with infectious lung disease and healthy controls, respectively. Serum MCP-1 levels in the PM/DM patients with ILD were significantly higher than those of the PM/DM patients without ILD, patients with infectious lung disease and healthy controls (all P values<0.01). Significant correlations were found between the elevated levels of serum MCP-1 and the presence of ILD in the patients with PM/DM (χ2=9.6, P<0.01). The sensitivity and specificity of serum abnormal MCP-1 levels for ILD in the patients with PM/DM were 60.7% and 68.2%, respectively. The incidence of fever, arthritis, decreased %DL(CO) , erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and serum ferritin were significantly higher in the MCP-1 raised group than in the MCP-1 normal group (all P values<0.005). Additionally, Spearman rank correlation analysis showed that serum MCP-1 levels were positively correlated with serum ferritin in peripheral blood in the patients with PM/DM. CONCLUSION: The levels of serum MCP-1 are significantly elevated in PM/DM and it is significantly associated with ILD complication, and may contribute to the early differentiation of ILD from lung infectious disease.

Intravenous immunoglobulin therapy in adult patients with polymyositis/dermatomyositis: a systematic literature review.

The objectives of this study are to review and summarize published information on the use, effectiveness, and adverse effects of intravenous immunoglobulin (IVIG) in patients with polymyositis (PM) or dermatomyositis (DM) and to search MEDLINE and CNKI (Chinese) databases from 1985 to 2011 to retrieve clinical research articles concerning IVIG in adult patients with PM/DM. Of the 14 articles selected, two were randomized controlled trials, nine prospective open studies, and three retrospective studies with a total of 308 adult patients. IVIG has been used successfully in the treatment of PM/DM. The standard dose is 2 g/kg, given in two to five individual daily doses. The course of IVIG treatment is usually 3~6 months. IVIG therapy seemed rarely employed as first-line therapy in PM/DM. In a double-blind study conducted in patients with refractory DM, IVIG combined with corticosteroid significantly improved muscle strength and decreased serum creatine kinase level, compared with placebo. The beneficial effect of IVIG in refractory, flare-up, rapidly progressive, or severe PM/DM has been documented in many open-label trials. IVIG was shown to be effective in most of PM/DM patients with lung involvement and esophageal involvement. In some patients, IVIG can lower the corticosteroid dose required for maintenance, demonstrating the most effective steroid-sparing effect. Adverse effects were generally tolerable. IVIG is effective in the treatment of adult patients with PM/DM and appears to be relatively well tolerated and safe. IVIG may be a good choice especially in patients with refractory, flare-up, rapidly progressive, or severe PM/DM, and can be tried in patients with a contraindication for corticosteroid.

[Glucagon like peptide-1 inhibits high glucose-induced injury of oxidative stress in cardiomyocytes of neonatal rats].

The present study was to investigate the effect of glucagon like peptide-1 (GLP-1) on high glucose-induced oxidative stress of cardiomyocytes and the possible role of the PI3K-Akt signal path in this process in the neonatal SD rats. With enzymatic digestion and immunofluorescence identification, cardiomyocytes after 72-96 h of primary culture were used in experiment. The cells were divided into 5 groups: normal control group, high glucose group, high glucose + GLP-1 group, high glucose + GLP-1 + LY294002 group and high osmolarity control group. The content of MDA was detected by TBA colouration method. The content of SOD was detected by xanthine oxidase method. The change of NADPH P47phox subunit mRNA quantity was detected by PCR gel electrophoresis. The level of ROS was detected by flow cytometry, and was also observed by fluorescence microscope. The DNA ladder was examined by agarose gel electrophoresis, and the cell apoptosis was determined by Annexin-V-FITC/PI flow cytometry, and the phosphorylation of Akt was determined by Western blotting. Compared with those in the normal control group, in the high glucose group, the cells grew poorly, and the beating rate was significantly lower (P < 0.05); The apoptotic rate was significantly increased (P < 0.05); The MDA content was increased (P < 0.05); It showed the typical DNA ladder, which is the characteristic of apoptosis; The SOD activity was decreased (P < 0.05); The level of intracellular ROS increased (P < 0.05); And the expression of NADPH P47phox subunit mRNA was increased; However the phosphorylation level of Akt was decreased. Pretreatment with GLP-1 improved the above-mentioned parameters and decreased the expression of NADPH P47phox subunit mRNA (P < 0.05). However, compared with the high glucose + GLP-1 group, LY294002, an inhibitor of PI3K-Akt signal path, attenuated the protective effect of GLP-1 in the high glucose + GLP-1 + LY294002 group. It is suggested that GLP-1 plays a protective role in the high glucose-induced injury and apoptosis of cardiomyocytes, and the PI3K-Akt signal path is involved in this process.

[A clinical study of femoral head osteonecrosis in patients with systemic lupus erythematosus.].

OBJECTIVE: To investigate the clinical features of osteonecrosis of the femoral head (ONFH) in patients with systemic lupus erythematosus (SLE). METHODS: The consecutive 461 SLE patients who underwent inpatient care in China-Japan Friendship Hospital were reviewed, the clinical data of 32 cases complicated with ONFH and 64 without ONFH as control was studied. RESULTS: The incidence of ONFH in 461 SLE patients was 6.94%. 65.63% of the ONFH was diagnosed within the first 3 years of SLE. It was found that the incidence of vasculitis, osteoporosis, high level of blood platelet, serum low density lipoprotein cholesterol (LDL-C) and fibrinogen was higher in SLE patients with ONFH than that in SLE patients without ONFH (P < 0.05). When compared with controls, the ONFH initial glucocorticoid dosage and accumulative dosage of glucocorticoid within the first month or six months were significantly higher in SLE patients with ONFH (P < 0.05). There was no significant difference between two groups in sex, age, duration of SLE, dental ulcer, Raynaud's phenomenon, hypocalcemia, renal diseases, hypertension, anemia, positive anticardiolipin antibodies and immunosuppresive treatment (P > 0.05). CONCLUSION: The incidence of ONFH in patients with SLE is relatively high within the first 3 years of SLE. The SLE patients with ONFH are more likely to have such clinical features as vasculitis, osteoporosis, high level of blood platelet, serum LDL-C and fibrinogen and exposed to high-dose glucocorticoid therapy.

Device design and simulation for GaN based dual wavelength LEDs.

A comprehensive optical model for dual wavelength LEDs is developed using optical ray tracing programs. Optical dispersion of GaN, InGaN, and AlGaN is also included in this numerical model. The light extraction efficiency of LEDs can be calculated based on LED structure and material properties. Moreover, a LED device structure can be optimized to improve the light extraction efficiency.

[A clinical study of tuberculosis infection in systemic lupus erythematosus].

OBJECTIVE: To investigate the characteristics and related risk factors associated with Tuberculosis(TB) in patients with systemic lupus erythematosus (SLE) who received glucocorticoid and immunosuppressive therapy. METHODS: Among the 452 SLE patients underwent the treatment of glucocorticoid and immunosuppressive agent, the clinical data was reviewed and summarized retrospectively. RESULTS: 42 of 452 (9.29%) patients were diagnosed as TB infection.11 patients (23.81%) had exudative pulmonary tuberculosis and 31 patients (73.81%) had extra-pulmonary TB. Statistics of the 31 patients showed that 8 patients (19.05%) had hematogenous disseminated pulmonary tuberculosis; 6 (14.29%) had tuberculo-meningitis; 2 (4.76%) had thoracic cavity TB; 2 (4.76%) had abdominal cavity TB; 1 (2.38%) had crewels; 1 (2.38%) had bone tuberculosis and 1 (2.38%) had nephronophthisis. The focus of infection was not found in 10 patients. Of all 42 patients with TB infection, 38 cases suffered form lupus nephritis, 40 with hypoalbuminosis, 10 with TB history, 14 had leucocytopenia or hyperglycaemia, respectively. The effect of antiTB therapy started up at least 7 days, or in 4 weeks as longest. 2 patients died of hematogenous disseminated pulmonary tuberculosis. CONCLUSION: Under the treatment of glucocorticoid and immunosuppressive agent, TB incidence in patients with SLE is obviously higher than that of common people. Extra-pulmonary TB and serious infection are more frequently. It is shown that those who had lupus nephritis or TB history are more susceptible to TB.

GaN-based distributed Bragg reflector for high-brightness LED and solid-state lighting.

A comprehensive numerical model for distributed Bragg reflectors (DBRs) based on thin-film optics is developed. Detailed refractive-index calculations for GaN, AlN, AlGaN, and InGaN can also be included in this numerical model. This model can predict DBR performances for refractive-index variations, layer-thickness fluctuations, and the number of quarter-wave stack pairs in DBR as well different light polarizations.

Numerical model of wavelength conversion through cross-gain modulation in semiconductor optical amplifiers.

A steady-state numerical model of wavelength conversion through cross-gain modulation in semiconductor optical amplifiers is described, which includes the spatial variations of the carrier density, gain coefficient, differential gain, and internal loss. Of particular interest is the analytic gain coefficient model, which is applied to the semiconductor optical amplifier converter problem for the first time to our knowledge. The model is used to compare performances of upconverters and downconverters for cases of long and short device lengths, and in large and small signal regimes. Comparisons with results of other studies are presented.