A new predicting model of preeclampsia based on peripheral blood test value.

OBJECTIVE: To identify laboratory markers among platelet indices, coagulation parameters, blood lipid parameters, and liver/kidney function variables that can be used to predict preeclampsia. PATIENTS AND METHODS: We studied records of 568 women with preeclampsia, gestational hypertension (GH), or normal term pregnancies hospitalized in the Obstetrics Department of the Fujian Maternal and Child Health Hospital from September 2014 to September 2018. We divided the patients' records into three groups (216 with preeclampsia, 136 with gestational hypertension, and 216 with normal pregnancies). We conducted retrospective analyses to compare variable measurements between the groups and find correlations. We looked into maternal pre-onset platelet indices, coagulation parameters (thrombin time [TT], fibrinogen [FIB]), biochemical parameters (total cholesterol [TC], triglycerides [TG], high-density lipoproteins [HDL], alanine transaminase [ALT], serum creatinine [CRE], blood urea nitrogen [BUN], uric acid [UA]), maternal complications, and perinatal outcomes. In addition to our statistical analysis, we trained a back-propagation (BP) neural network to identify the strongest predictors of preeclampsia. RESULTS: We found significant differences among the groups in terms of values for PLT, MPV, PDW, PLCR, TT, FIB, TG, LDH, BUN, and others. After adjusting for confounding factors in a multivariate ordered logistic regression model, we found that mean values for MPV, BUN, TG, and LDH can independently predict the risk of preeclampsia (the OR values were 1.858, 1.583, 1.104, and 1.020, respectively), the C-index (concordance statistic) was 0.73. Also, our BP neural network derived ALB, MPV, BUN, LDH and TG as the strongest predictors of preeclampsia. CONCLUSIONS: MPV, TG, LDH, and BUN can help establish the risk for the development of preeclampsia to apply active measures and improve maternal and perinatal outcomes. The BP neural network can be used to study predictive models of preeclampsia.

Role of visfatin in promoting proliferation and invasion of colorectal cancer cells by downregulating SDF-1/CXCR4-mediated miR-140-3p expression.

OBJECTIVE: Visfatin is significantly upregulated in colorectal cancer (CRC). However, its exact role in CRC progression and the regulatory mechanism involved in this process have not been fully illuminated. The aim of this study was to investigate the roles of visfatin in CRC progression and the potential molecular mechanism. MATERIALS AND METHODS: In vitro, two CRC cell lines (DLD-1 and SW480) were transfected with visfatin, si-visfatin, and their control vectors. Some cells were transfected with miR-140-3p mimics or miRNA negative control. Cell Counting Kit-8 and transwell invasive assays were used to detect cell proliferation and invasion ability. Luciferase reporter assays were performed to confirm whether CXC motif chemokine receptor 4 (CXCR4) directly targets miR-140-3p. Western blotting and qRT-PCR analyses were respectively conducted to evaluate the protein and mRNA levels of stromal cell-derived factor-1 (SDF-1) and CXCR4. In vivo, DLD-1 cells transfected with visfatin construct or vector control were inoculated into nude mice. After 5 weeks, the mice were sacrificed, and the tumor nodules were weighed. The expression of visfatin, SDF-1, and CXCR4 in tumor tissues was detected via immunohistochemistry analysis. RESULTS: In vitro, the transfection of visfatin promoted the proliferation and invasion of CRC cells, as well as upregulated the expression of SDF-1/CXCR4. MiR-140-3p directly targets the 3'untranslated region of CXCR4. MiR-140-3p expression was downregulated by treatment with visfatin, and miR-140-3p exerted similar effects to those of visfatin knockdown on the proliferation and invasion of CRC cells. In vivo, visfatin stimulated CRC tumor growth and downregulated miR-140-3p expression, whereas it upregulated SDF-1/CXCR4 expression. CONCLUSIONS: Visfatin promotes CRC progression by downregulating the SDF-1/CXCR4-mediated expression of miR-140-3p both in vitro and in vivo.

Effect of exosomes derived from MiR-133b-modified ADSCs on the recovery of neurological function after SCI.

OBJECTIVE: To investigate the recovery effect of exosomes derived from micro ribonucleic acid (miR)-133b-modified adipose-derived stem cells (ADSCs) on neurological function after spinal cord injury (SCI) and its mechanism. MATERIALS AND METHODS: The SCI model of rats was used and divided into the following 5 groups: sham-operation group, 4 d SCI group, phosphate-buffered saline (PBS) group, miR-control group and miR-133b group. At 96 h after operation, rats were euthanatized, and spinal tissues were removed. Next, the level of miR-133b was detected via reverse transcription-polymerase chain reaction (RT-PCR), and the expression of RhoA protein was measured via Western blotting. Moreover, expressions of proteins associated with the axon regeneration pathway, including phosphorylated-cAMP-response element binding protein (p-CREB), CREB, phosphorylated-signal transducer and activator of transcription 3 (p-STAT3) and STAT3, along with expressions of neurofilament (NF), growth associated protein 43 (GAP43), glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP), were tested by Western blotting and immunofluorescence staining. RESULTS: The miR-133b mimics significantly upregulated the expression of miR-133b in adipose-derived stem cells (ADSCs), compared to blank group (p<0.05). The expression of miR-133b was significantly decreased in 4 d SCI group compared with that in sham-operation group (p<0.001). The RhoA expression was statistically increased in 4 d SCI group compared with that in sham-operation group (p<0.001), and it was partially impaired by using miR-133b compared with that in 4 d SCI group (p<0.001). Expressions of NF, GAP43, GFAP and MBP were remarkably higher in 4 d SCI group than those in sham-operation group (p<0.01), and they were also significantly increased in miR-133b group than those in 4 d SCI group (p<0.01). Besides, our data showed a significant increase of p-CREB/CREB, p-STAT3/STAT3, NF, GAP-43, GFAP and MBP in miR-133b group compared to those in 4 d SCI group, with statistical reduction of RhoA (p<0.05). CONCLUSIONS: We showed that exosomes derived from miR-133b-modified ADSCs can significantly promote the recovery of neurological function of SCI animals through affecting the signaling pathway related to axon regeneration and expressions of NF, GAP-43, GFAP and MBP.

[Analysis of neurobehavioral function of school-aged children with sleep disordered breathing].

Objective: To investigate the neurobehavioral function(attention, executive skills, behavior) of school-aged with varying degrees of SDB and control children with no history of SDB recruited from the community.Method: One hundred and sixty-three children aged from 7 to 12 were enrolled in the study. Children were devided into 4 groups through the data of Routine overnight polysomnography(PSG): PS(n=71) group, mild OSAHS (n=29) group, moderate/severe OSAHS(n=21) group, and controls(n=42) group. The Behavior Rating Inventory of Executive Function(BRIEF) and the Child Behavior Checklist(CBCL) were used to assess attention, executive function and behavioral function. Result: There was significant difference of AHI, OAI, RAI, SAI and SpO 2 nadir between the mild/MS groups and the control/PS groups(F=1174.3, 1178.0, 2348.3, 34.7, 377.7, P<0.05). Total sleep time(TST) of the MS OSAHS group was significantly less than that in the control group(F=178.8, P<0.05). Increased rates of behavioral executive dysfunction were found depending on the SDB spectrum(F=181.2, 274.2, 284.5, P<0.05). Children with all severities of SDB had signicantly higher rates of total, internalizing and externalizing behavioral problems compared to control group(F=361.7, 168.3, 564.0, P<0.05). Conclusion:Our study suggests that behavioral, attention, and executive function difficulties are present in children with PS as well as OSAHS. These results have implications for the treatment of milder forms of SDB, particularly PS, which is commonly viewed as benign.

[The combination of percutaneous iohexol-ethanol injection with radiofrequency ablation for the treatment of primary liver cancer in high-risk locations].

Objective: To investigate the safety and efficacy of radiofrequency ablation (RFA) with percutaneous iohexol-ethanol injection (PIEI), compared with RFA plus transcatheter arterial chemoembolization (TACE) for patients with primary liver cancer(PLC)in high-risk locations. Methods: From January 2012 to December 2014, 54 patients with PLC in high-risk locations were enrolled. They were divided into Group A (RFA combined with PIEI) and Group B (RFA plus TACE). The efficacy and adverse events were assessed. Results: 54 patients had 74 lesions in high-risk locations. There were 26 cases with 40 lesions in Group A, and 28 cases with 34 lesions in Group B. The complete ablation rate of Group A was significantly higher than that of Group B (92.5% vs 70.6%, P=0.014). The two-year local tumor progressionrateand two-year overall survival rate were similar between these two groups (Group A 20.0% vs Group B 38.2%, P=0.083; 90.3% vs 84.3%, P=0.523). Furthermore, the surgery-related severe adverse events of Group A (7.1%, one case of liver abscess and one case ofhematobilia) were more common than that of Group B (0%, P=0.491). No significant differences were found in common adverse events including fever, pain, elevation of aminotransferase and bilirubin. Conclusions: Compared with RFA plus TACE, RFA plus PIEI resulted inbetter complete ablation rate in patients with primary liver cancer in high risk locations. Prospective, randomized, controlled trials are warranted for further evaluation.

[Efficacy of intratympanic gentamicin and dexamethasone in the treatment of intractable Meniere's disease].

Objective:To investigate the efficacy and safety of low-dose intratympanic gentamicin (ITG) compared with intratympanic dexamethasone (ITD) in patients with intractable Meniere's disease (MD). Method:Seventy patients affected by definite unilateral MD were enrolled. 1 ml of gentamicin sulfate(40 g/L) was buffered with 0.5 ml of sodium bicarbonate to obtain a 6.4 pH solution with 26.7 g/L concentration. Thirty-five patients were treated with the buffered gentamicin solution on every week for 2 times. Thirty-five patients were treated with ITD (5 mg) in the first two days, and then every week for 4 weeks. At 2-year follow-up, mean outcome measurements consisted of control of vertigo attacks, pure tone average (PTA), dizziness handicap inventory and tinnitus handicap inventory.Result:Among 34 cases with complete follow-up data in the ITG group, complete control of vertigo (class A) was achieved in 27 patients and substantial control of vertigo (class B) in 5 patients. Among 32 cases with complete follow-up data in the ITD group, class A and B were achieved in 13 and 6 patients respectively (P< 0.05). There were no statistically significant variations between the two groups in PTA and THI (t= 1.737 and t=－0.197, P> 0.05).Conclusion:Low-dose ITG achieves better outcome than ITD in the control of vertigo attacks in patients suffering from unilateral intractable MD, with a very low incidence of hearing deterioration.

[Clinical analysis of benign paroxysmal positional vertigowith multiple canal involvement].

Objective:To compare the clinical features and outcomes between patients with multi-canal benign paroxysmal positional vertigo(BPPV) and single-canal BPPV.Method:Five-hundred and seventy-eight patients with BPPV were retrospectively analyzed and divided into three groups: single-canal BPPV(526 cases),multi-canal BPPV in unilateral ear(11 cases) and multi-canal BPPV in both ears(41 cases).All patients were diagnosed by using the Dix-Hallpike test or roll test and treated with the canalith repositioning procedure.The following factors,including aetiology,age,sex,response to treatment and recurrence,were compared among the three groups.Results:①Greater percentage of idiopathic cases were identified in single-canal(66.2%:48.2%,P<0.01).Traumatic origin and prior history of BPPV were more common in bilateral multi-canal(41.6%:9.2%,P<0.05)and unilateral multi-canal (36.2%:0,P<0.01)respectively.②The recurrence rate was higher in multi-canal BPPV(40.4%:14.3%,P<0.01).Conclusion:Idiopathic BPPV is more common in single-canal BPPV.Potential causes may be identified in multi-canal BPPV.However,over 90% of the patients with single-canal and multi-canal BPPV are cured.

[Value of videonystagmography and electrocochleography in prognosis prediction of patients with acute low-tone sensorineural hearing loss].

Objective:To predict the prognosis of acute lowtone sensorineural hearing loss（ALHL）by using the videonystagmography(VNG) and electrocochleography(ECochG).Method:A retrospective study was done in 70 patients with ALHL after long-term follow-up. The recurrence rate and rate of progression to definite Meniere 's disease were determined according to the results of VNG and ECochG tests at the onset of the first episode of hearing loss.Result:Twentynine patients（41.4%）experienced recurrent hearing loss and 5 patients（7.1%）developed to Meniere's disease. In patients with an elevated SP/AP ratio and spontaneous nystagmus, the recurrence rate was 81.8%. However, in those with a normal SP/AP ratio and without spontaneous nystagmus, the recurrence rate was 23.3%.There was a statistically significant difference in the progression rate of Meniere's disease between the groups with(15.2%) and without spontaneous nystagmus.Conclusion:It has a certain reference value to predict prognosiswhen spontaneous nystagmus and an elevated SP/AP ratio are detected on initial examination in patients with ALHL.

Effect of dietary supplementation of rutin on lactation performance, ruminal fermentation and metabolism in dairy cows.

The effect of long-term dietary supplementation with rutin on the lactation performance, ruminal fermentation and metabolism of dairy cows were investigated in this study. Twenty multiparous Chinese Holstein cows were randomly divided into four groups, and each was offered a basal diet supplemented with 0, 1.5, 3.0 or 4.5 mg rutin/kg of diet. The milk yield of the cows receiving 3.0 and 4.5 mg rutin/kg was higher than that of the control group, and the milk yield was increased by 10.06% and 3.37% (p < 0.05). On the basis of that finding, the cows supplemented with 0 or 3.0 mg rutin/kg of diet were used to investigate the effect of rutin supplementation on blood metabolites and hormone levels. Compared with the control group, the serum blood urea nitrogen (BUN) concentration of the 3.0 mg rutin/kg group is significantly decreased (p < 0.05). In another trial, four adult cows with permanent rumen fistula and duodenal cannulae were attributed in a self-control design to investigate the peak occurrence of rutin and quercetin in different parts of the gastrointestinal tract, ruminal fermentation and microbial population in dairy cows. The cows supplemented with 3.0 mg rutin/kg in the diet differed from the control period. Samples of rumen fluid, duodenal fluid and blood were collected at 1, 2, 3, 4, 5, 6, 7 and 8 h after morning feeding. Compared to the control group, the pH, ammonia nitrogen concentration, number and protein content of rumen protozoa and blood urea nitrogen were lower, but the concentration of total volatile fatty acid (TVFA), microbial crude protein (MCP) and serum lysozyme content were higher for the cows fed the rutin diets. The addition of 3.0 mg rutin/kg to diets for a long term tended to increase the milk yield and improve the metabolism and digestibility of the dairy cows.

Contact electrification and energy harvesting using periodically contacted and squeezed water droplets.

We investigate the contact electrification occurring when a small water droplet resting on a metal electrode is brought periodically in contact with a hydrophobic film of fluorinated ethylene propylene. It is found that the maximum current increases with the drop volume according to a power law. The time scale for the contact current to develop is consistent with that required for a droplet to spread and is, therefore, longer than the time required to form the electric double layer. Adding salt into the water does reduce the contact current but not entirely, which suggests that any remaining water layer cannot entirely neutralize the charges developed upon contact. With an average power of 0.7 µW and a peak power near 5 µW at a frequency of 5 Hz, a 200 µL droplet of pure water can be used to light up a light-emitting diode.

Effect of urokinase on cerebral perfusion after cardiopulmonary resuscitation in rabbits.

BACKGROUND: Cerebral resuscitation after cardiac arrest (CA) is always an unresolved problem in medical field. The decreased cerebral perfusion or nonperfusion caused by coagulation and fibrinolytic system function disorder and cerebral microthrombosis after CA and cardiopulmonary resuscitation (CPR) is one of the important reasons. MATERIALS AND METHODS: TTo investigate the effect of urokinase on cerebral microcirculatory perfusion after CA and CPR in rabbits. 20 rabbits were randomly divided into experimental group and control group, 10 rabbits in each group. Potassium chloride injection combined with asphyxia method was conducted to establish the CA models. CPR and basic life-support were performed on experimental group. Based on above treatments, intervention with urokinase was conducted on experimental group. Dual-slice spiral CT cerebral perfusion imaging was performed to observe the cerebral blood flow (CBF), cerebral blood volume (CBV) and top teep time (TTP). RESULTS: CBF and CBV in experimental group were significantly higher than those in control group, respectively (p < 0.01), and TTP in experimental group was significantly shorter than control group (p < 0.01). The cerebral perfusion in experimental group was better than control group. CONCLUSIONS: Thrombolytic therapy with urokinase in CPR after CA can improve the cerebral microcirculatory perfusion in rabbits.

Stable transfection and identification of a hair follicle-specific expression vector of IGFBP-5 in goat fetal fibroblasts.

The insulin-like growth factor-binding protein-5 (IGFBP-5) is one of the 6 members of the IGFBP family and is involved in the regulation of cell growth, apoptosis, and other IGF-stimulated signaling pathways. To determine the significance of IGFBP-5 in the Inner Mongolia Cashmere goat (Capra hircus), a hair follicle-specific expression vector of IGFBP-5, pCDsRed2-K-IGFBP5 (6.7 kb), was constructed by cloning IGFBP-5 downstream of the keratin-association protein (KAP)6-1 promoter and inserting this fragment into pCDsRed2, which contains a red fluorescent protein (DsRed) expression unit. Inner Mongolia Cashmere goat fetal fibroblast (GFb) cells were transfected with the expression vector by using Lipofectamine(TM) 2000. Cell clones that stably expressed red fluorescence were obtained after selection with Geneticin (G418). The transgene in the cell clones was examined by polymerase chain reaction to verify that exogenous DNA (pKAP6-1 and IGFBP-5) had integrated stably into GFb cells. These data suggest that this method can be used for the construction of a hair follicle-specific expression vector for functional genetic analyses and for obtaining stable transfection donor cells for nuclear transfer.

Molecular Characterization and Expression Pattern of Gene IGFBP-5 in the Cashmere Goat (Capra hircus).

Insulin-like growth factor-binding protein-5 (IGFBP-5) is one of the six members of IGFBP family, important for cell growth, apoptosis and other IGF-stimulated signaling pathways. In order to explore the significance of IGFBP-5 in cells of the Inner Mongolian Cashmere goat (Capra hircus), IGFBP-5 gene complementary DNA (cDNA) was amplified by reverse transcription polymerase chain reaction (RT-PCR) from the animal's fetal fibroblasts and tissue-specific expression analysis was performed by semi-quantitative RT-PCR. The gene is 816 base pairs (bp) in length and includes the complete open reading frame, encoding 271 amino acids (GenBank accession number JF720883). The full cDNA nucleotide sequence has a 99% identity with sheep, 98% with cattle and 95% with human. The amino acids sequence shares identity with 99%, 99% and 99%, respectively. The bioinformatics analysis showed that IGFBP-5 has an insulin growth factor-binding protein homologues (IB) domain and a thyroglobulin type-1 (TY) domain, four protein kinase C phosphorylation sites, five casein kinase II phosphorylation sites, three prenyl group binding sites (CaaX box). The IGFBP-5 gene was expressed in all the tested tissues including testis, brain, liver, lung, mammary gland, spleen, and kidney, suggesting that IGFBP-5 plays an important role in goat cells.

Utility of semivariogram for spatial variation of soil nutrients and the robust analysis of semivariogram.

The spatial variation of soil nutrients in topsoil (0-20 cm) was analyzed using semivariogram in the Zunhua County of Hebei Province, China. The effect on semivariogram with randomly deleted data and kriged estimates using various reduced sample sizes was also analyzed. The semivariograms of available N, total N, available P, organic matter were best described by a spherical model, except for available K, which best fitted a complex structure of exponential model and linear with sill model. The ratio of nugget to total sample variance ranged from 34.4% to 68.4%, indicating the spatial correlation of tested soil nutrients on a large scale was moderately dependent. Among five soil nutrients, available nitrogen and available phosphorus had the shortest spatial correlation range (5 km and 5.5 km), available K had the longest range (25.5 km), whereas total nitrogen and organic matter had intermediate spatial correlation range (14.5 km and 8.5 km). The semivariograms of available N, total N, available P, and organic matter were insensitive to a 50%-60% reduction in original sampling density, while for available K, it is up to 70%. The estimated spatial distributions of total N by kriging, under various reduced sample sizes, all correlated significantly (P = 0.001) with those obtained from original data. The results showed that the semivariogram was a relatively robust tool when used in a large region and sufficient spatial variation information could be retained regardless of a higher deletion proportion of the original data. The original sample data could be reduced by kriging and the estimates showed no loss of spatial information, however, the results may be unreliable unless a clearly identified semivariogram model could be obtained. The results may provide useful information for determining the appropriate sampling densities for these scales of soil survey.

Pigmented renal clear cell carcinoma with melanocytic differentiation.

Renal cell carcinoma (RCC) is the most common malignant tumor of the adult kidney, and its incidence has been steadily rising. RCC consists of several subtypes, each of which has its own clinical features, and cytogenetic and molecular characteristics. Recognizing histologic patterns of RCC is important not only for correct diagnosis, but also for providing insight into the biological behavior of the tumor and subsequent appropriate medical care for the patient. Pigments other than hemosiderin has been observed in RCC, but none of them have been proved to be melanin. Melanotic tumors, either primary or metastatic, are rare in the kidney. We present an unusual case of melanin-pigmented clear cell RCC with melanocytic differentiation, an unusual variant that may lead to errors in diagnosis and treatment.

[Neocartilage formation in vitro using transduced mesenchymal stem cells cultured on biomimetic biodegradable polymer scaffolds].

OBJECTIVE: To investigate the effect of transforming growth factor (TGF) beta 1 gene transfection on the growth of mesenchymal stem cells(MSCs) and to evaluate a new biomimetic biodegradable polymer as scaffolds for applications in articular cartilage tissue engineering. METHODS: Principles of tissue engineering were combined organically with principles of gene therapy to produce cultured periosteum-derived MSCs transduced with the full-length rat TGF-beta 1 cDNA in vitro. These cells were then seeded onto three-dimensional porous poly-DL-lactide scaffolds modified with poly-L-lysine that mimicked cell-binding domains found on natural extracellular matrix to promote specific cell adhesion. The adhesion, proliferation, and differentiation of the transfected MSCs were examined with scanning electron microscope within 2 weeks. RESULTS: All cells adhered to the biomimetic matrices well, but more cartilage-like tissue was formed for TGF-beta 1 gene modified MSCs/scaffolds composites than for the control groups. Transfer of gene encoding TGF-beta 1 to MSCs promoted its proliferation and differentiation significantly. CONCLUSIONS: The TGF-beta 1 gene transduced MSCs/biomimetic matrix composites used in this study was the first attempt to apply the principles of molecular tissue engineering for articular cartilage repair. This new molecular tissue engineering approach could be of potential benefit to repair damaged articular cartilage, especially in osteoarthritis. The new biomimetic biodegradable polymer matrices modified with biomolecules not only have good structural compatibility, but also have better interfacial compatibility and bioactivity, and can be used as scaffolds for articular cartilage tissue engineering.

Interactions at the NH2-terminal interface of cardiac troponin I modulate myofilament activation.

Cardiac troponin I (cTnI) is an essential element in activation of myofilaments by Ca2+ binding to cardiac troponin C (cTnC). Yet, its role in transduction of the Ca2+ binding signal to cardiac troponin T (cTnT) and tropomyosin-actin remain poorly understood. We have recently discovered that regions of cTnI C-terminal to a previously defined inhibitory peptide are essential for full inhibitory activity and Ca(2+)-sensitivity of cardiac myofilaments (Rarick et al., 1997). However, apart from its role in structural binding to cTnC, there is little knowledge concerning the role of the N-terminus of cTnI in the activation and regulation of cardiac myofilaments. To address this question, we generated wild-type mouse cardiac TnI (WT-cTnI; 211 residues) and two N-terminal deletion mutants of mouse cTnI, cTnI54-211 (missing 53 residues), and cTnI80-211 (missing 79 residues). The cTnI54-211 mutant retained the ability to bind to cTnT, but lost the ability to bind to cTnC, whereas the cTnI80-211 mutant lost the ability to bind to cTnT, but bound weakly to cTnC. Both mutants bound to F-actin. In the absence of Ca2+, cTnI54-211 was able to inhibit the unregulated MgATPase activity of myofibrils lacking endogenous cTnI-cTnC to the same extent as WT-cTnI, whereas cTnI80-211 had some impairment of its inhibitory capability. Reconstitution with cTnI54-211/cTnC complex did not restore Ca(2+)-activation of myofibrillar MgATPase activity at all, however, the cTnI80-211/cTnC complex restored Ca(2+)-activation to nearly 50% of that obtained with WT-cTnI/cTnC. These data provide the first evidence of a significant function of a cTnT-binding domain on cTnI. They also indicate that the structural cTnC binding site on cTnI is required for Ca(2+)-dependent activation of cardiac myofilaments, and that cTnT binding to the N-terminus of cTnI is a negative regulator of activation.

Myocardial uptake of iodine-125-labeled 15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid is decreased in chronic diabetic rats with changes in subcellular distribution.

Iodine-123-labeled 15-(p-iodophenyl)-3-(R,S)-methyl pentadecanoic acid (123I-BMIPP) is widely used to detect myocardial metabolic changes, but the preferred energy substrates in the myocardium would be expected to be altered in the presence of metabolic disorders such as diabetes mellitus (DM). We investigated the metabolism of branched-chain fatty acids in the myocardium of rats with DM. Streptozotocin-induced DM rats were examined 48 h (acute; AD) and 6 weeks (chronic; CD) after injection of streptozotocin. Hearts were excised 15 min or 60 min after injection of 0.185 MBq of 125I-BMIPP, followed by homogenization in an EDTA-Tris buffer. The homogenates were subjected to differential centrifugation to obtain the mitochondrial (MF) and cytoplasmic (CF) fractions. Myocardial 125I uptake tended to increase in the AD group, but the change was not significant. Myocardial 125I uptake at 15 min was significantly lower in the CD group than in the control group, even in the insulin-treated rats [control (CC), 4.4+/-0.4; not treated (CDN), 3.3+/-0.5; insulin-treated (CDI), 3.4+/-0.4 x 10(4) cpm/g, p<0.05 in each case]. The 125I count value corrected for the blood count (counts/min (cpm) per g of protein divided by blood cpm) in the MF decreased by 40% at 60 min in the CC group, but increased by 60% in the CDN group. The results of the present study suggest that the myocardial uptake of branched-chain fatty acids is decreased in rats with chronic diabetes, probably as a result of mitochondrial dysfunction.

Compressive fatigue behavior of bovine trabecular bone.

We studied the fatigue behavior of bovine trabecular bone specimens under stress control using a sinusoidal uniaxial compressive load profile with a frequency of 2 Hz. The stress range was determined from the corresponding initial global platen-to-platen strain range, where the maximum initial strain was between 0.8 and 2.1% and the minimum strain was 0.6%. The local strain distribution was measured on the same type of specimen by affixing glass spheres and photographing them in the unloaded and loaded positions using multiple exposures. The number of cycles to failure (defined as a 5% decrease in secant modulus) was strongly correlated with the initial global maximum strain (r2 = 0.78) and ranged from 20 cycles at 2.1% strain to 400,000 cycles at 0.8% strain. All of the fatigue specimens showed a region of transverse failure approximately 1 mm from the end of the specimen. Microscopic examination of the failure zones revealed two failure modes: a straight transverse brittle-like fracture through the trabeculae, most often found in trabeculae transverse to the loading direction, and buckling-like failure, common in oblique trabeculae, involving bending and splitting. The local strain increased towards the ends of the specimens to a value 2-4 times that in the middle. Modulus degradation with the number of cycles was distinctively different for high-cycle and low-cycle fatigue, suggesting the possibility that both creep and damage accumulation contribute to fatigue failure of trabecular bone.