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1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(2): 382-384, 2020 Apr 18.
Artículo en Zh | MEDLINE | ID: mdl-32306027

RESUMEN

In recent years, there have been more and more reports about cystadenoma. Cystadenoma can occur in many parts of the body, and cystadenoma in different parts may show different clinical symptoms, however, some patients with cystadenoma have no symptoms. The vast majority of cystadenomas are benign lesions, but a small number of cystadenomas can be malignant. For example, a small number of ovarian cystadenomas and pancreatic cystadenomas may be malignant. This study reported a patient with small intestinal cystadenoma diagnosed by pathology. The patient's physical examination revealed a lesion in the left upper abdomen. He had only abdominal distension and no other discomfort. His laboratory examination results were basically normal, i.e. blood routine, urine routine, stool routine, liver function, kidney function, myocardial enzyme, tumor marker, etc. The patient underwent sectional small intestine resection and the pathological sample was analyzed. The histological findings of the resected intestinal sample were consistent with cystadenoma. Computed tomography scan of the abdomen was performed 4 months after the surgery. No recurrence of the tumor was found. The patient recovered in good condition. By consulting the literature, I found very few reports of small intestinal cystadenoma before, it was very rare. This article described the clinical manifestation, diagnosis and differential diagnosis, treatment and prognosis of a case of small intestinal cystadenoma, it suggested that cystadenoma can occur in the small intestine, other than the ovary, pancreas, liver, lung, thyroid, prostate, seminal vesicle, skin, etc. The cystadenoma in small intestine is easy to be mistaken with other tumors, such as small intestine stromal tumor, small intestine adenocarcinoma, small intestine lipoma, small intestine hemangiomas, etc., and it is difficult to fully confirm through imaging examinations, such as computed tomography and magnetic resonance imaging. Laparotomy and histopathological examination are necessary before definitive diagnosis. This disease can be treated by small bowel resection at the affected region and good prognosis can be achieved.


Asunto(s)
Cistoadenoma , Neoplasias Intestinales , Humanos , Intestino Delgado , Masculino , Recurrencia Local de Neoplasia , Neoplasias Pancreáticas , Próstata
2.
Zhonghua Yi Xue Za Zhi ; 100(6): 456-459, 2020 Feb 18.
Artículo en Zh | MEDLINE | ID: mdl-32146770

RESUMEN

Objective: To compare the curative effect of mesenchymal stem cells derived from human Wharton's Jelly(WJ-MSC) or adipose(AD-MSC) culture supernatant on endothelial cells angiogenesis. Methods: WJ-MSC and AD-MSC were isolated, identified, and the culture supernatant of stem cells was collected.The WJ-MSC or AD-MSC supernatant co-cultured with the endothelial cells. The expression levels of pro-angiogenic and anti-angiogenic genes of endothelial cells were assessed using qRT-PCR analysis, and the effects of stem cell culture supernatant on angiogenesis were evaluated by performing a tube formation assay in vitro. Results: After adding WJ-MSC and AD-MSC culture supernatant, the expression levels of pro-angiogenic genes in endothelial cells were upregulated, and the expression levels of anti-angiogenic genes were downregulated significantly in both experimental groups compared to the control group (P<0.01), and tube formation of endothelial cells was also significantly increased in both experimental groups as determined by the increase of the tube length ((43.2±9.2) mm vs (94.3±13.2)mm, (86.1±7.2)mm, P<0.01). Conclusion: The results showed that AD-MSC culture supernatant can promote endothelial cells angiogenesis and its curative effect is similar to that of WJ-MSC.


Asunto(s)
Células Madre Mesenquimatosas , Gelatina de Wharton , Adipocitos , Técnicas de Cultivo de Célula , Diferenciación Celular , Proliferación Celular , Técnicas de Cocultivo , Células Endoteliales , Humanos
3.
Zhonghua Er Ke Za Zhi ; 62(7): 681-685, 2024 Jul 02.
Artículo en Zh | MEDLINE | ID: mdl-38955688

RESUMEN

Objective: To evaluate the effectiveness and safety of treatment with Burosumab in pediatric X-linked hypophosphatemia (XLH) patients. Methods: In this retrospective case study, 4 children with pediatric XLH, who were treated with Burosumab in Beijing Children's Hospital, Capital Medical University and Shandong Provincial Hospital affiliated to Shandong First Medical University from July 2022 to December 2023, were selected as the study objects. We collected and analyzed their clinical characteristics, biochemical indicators, imaging results, and treatment. The children were followed up every 3 months until December 2023, and the clinical outcomes and adverse drug reactions after treatment were evaluated. Results: Of the 4 patients, 3 were males and 1 was female; they were aged 6.7, 2.9, 2.1, and 2.3 years, respectively. Three patients had previously received treatment with phosphate supplements and active vitamins, but their wadding gait and lower limb deformities did not improve significantly, neither did their imaging changes of active richets. The initial dose of Burosumab in the 4 patients was 0.8 mg/kg, administered subcutaneously every 2 weeks, with a treatment course of 0.8-1.3 years. The fasting serum phosphorus and tubular maximum reabsorption of phosphate/glomerular filtration rate (TmP/GFR) of the 4 patients before treatment were 0.72, 0.95, 0.81, 0.66 mmol/L and 0.67, 0.85, 0.87, 0.61 mmol/L, respectively. At the last follow-up, the fasting serum phosphorus and TmP/GFR levels were significantly increased (0.96, 1.09, 1.09, 0.90 mmol/L, and 0.85, 0.79, 1.03, 0.98 mmol/L, respectively). Among them, only the TmP/GFR level (1.17 mmol/L) in case 2 achieved normal values at 3 months post-therapy, while the rest did not reach the normal range for children of the same age. After treatment, the alkaline phosphatase levels of all patients gradually decreased (the values were 461, 240, 423, and 237 U/L, respectively), and the ALP levels in cases 2 and 4 returned to normal at the last visit. Case 4 showed a slight increase in parathyroid hormone (PTH) levels after 9 months of treatment, while the PTH levels in the rest 3 cases remained normal. Case 1 underwent a 6-minute walking test, and the walking distance increased from 245 m to 570 m. Abnormal gait, lower limb deformity, and the severity of rickets in the 4 patients had all improved. No adverse drug reactions such as nephrocalcinosis, local skin injection reaction, hyperphosphatemia, or vitamin D deficiency were observed. Conclusion: Burosumab can improve clinical symptoms in children with XLH with a good safety profile.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Raquitismo Hipofosfatémico Familiar , Humanos , Masculino , Femenino , Raquitismo Hipofosfatémico Familiar/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/uso terapéutico , Niño , Estudios Retrospectivos , Preescolar , Resultado del Tratamiento
4.
Eur Rev Med Pharmacol Sci ; 27(1): 224-232, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36647872

RESUMEN

OBJECTIVE: To detect the display rate and flow velocity of intracranial circle of Willis (anterior, middle, and posterior cerebral arteries) with transcranial contrast-enhanced transcranial color-coded sonography (CE-TCCS), using digital subtraction angiography (DSA) as the golden diagnostic standard. PATIENTS AND METHODS: We collected data from 104 patients with suspected stroke treated in our hospital between December 2019 and October 2021. The detection rate of the intracranial circle of Willis, anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) were analyzed based on routine TCCS and CE-TCCS data. Based on digital subtraction angiography (DSA) data, the degree of MCA stenosis was divided into mild stenosis (<50%), moderate stenosis (50-69%), severe stenosis (70-99%), and bilateral middle cerebral artery CE-TCCS examinations were performed. We evaluated MCA color blood flow on CE-TCCS, and recorded the peak systolic velocity (PSV), end-diastolic velocity (EDV), and mean flow velocity (MFV). RESULTS: The display rates of ACA, MCA, and PCA were significantly improved on the CE-TCCS, and the PSV, EDV and MFV of the MCA stenosis group were higher than those of the normal group. The flow velocity of each stenosis subgroup was increased compared to the normal group. The optimal cutoff values of normal and stenosis under the receiver operating characteristic (ROC) curve were PSV = 168.5 cm/s, EDV = 61.5 cm/s, and MFV = 110.5 cm/s. The optimal cutoff values for mild and moderate stenosis and for moderate and severe stenosis were PSV = 201.5 cm/s and 249.5 m/s, EDV = 95.2 cm/s and 141.5 cm/s, and MFV = 137.6 cm/s and 160.5 cm/s, respectively. PSV and MFV had the most significant sensitivity, specificity, and accuracy. CONCLUSIONS: Transcranial contrast-enhanced ultrasonography can improve the display rate of intracranial blood vessels and can accurately diagnose MCA stenosis.


Asunto(s)
Trastornos Cerebrovasculares , Arteria Cerebral Media , Humanos , Arteria Cerebral Media/diagnóstico por imagen , Constricción Patológica/diagnóstico por imagen , Sensibilidad y Especificidad , Ultrasonografía Doppler Transcraneal , Velocidad del Flujo Sanguíneo , Ultrasonografía
5.
Zhonghua Er Ke Za Zhi ; 59(2): 125-130, 2021 Feb 02.
Artículo en Zh | MEDLINE | ID: mdl-33548959

RESUMEN

Objective: To analyze the clinical and genetic features, as well as the treatment outcomes of two boys with nephrogenic syndrome of inappropriate antidiuresis (NSIAD) caused by gain-of-function mutations in the V2 vasopressin receptor gene (AVPR2). Methods: The clinical manifestations, genetic testing, therapeutic interventions and the outcomes of two boys with NSIAD hospitalized in the Department of Endocrinology, Beijing Children's Hospital in April 2019 were reported. A literature search with "Nephrogenic syndrome of inappropriate antidiuresis" and "AVPR2 gene" as keywords was conducted at the China national knowledge infrastructure (CNKI), the Wanfang Data Knowledge Service Platform, PubMed and Springer Link up to May 2020. Relevant published articles were reviewed. Results: The two cases presented with chronic and severe hyponatremia with hypo-osmolality, inappropriately elevated urinary osmolality and urinary sodium levels. The onset age was 5.25-years and 2 months respectively. AVPR2 sequencing revealed a previously described hemizygous activating mutation (c.409C>T, p.R137C) in both of boys, each inherited the variant from their mother. Patient 1 limited fluid intake by himself in his daily life, intravenous and oral sodium supplementations showed no significant increase of serum sodium level. Oral furosemide increased the serum sodium level and maintained it within normal range. The serum sodium and potassium levels were in the normal range during the 1-year follow-up period with oral furosemide. The serum sodium level of Patient 2 increased with restricting fluid intake and with salt supplementation. However, after he experienced respiratory infection, the plasma sodium level decreased. Subsequently, oral anti-infection medicine and furosemide were applied. The serum sodium level increased two days later and remained at a normal range afterwards. The boy was 1 year old with normal growth. He stopped taking furosemide after 4 months while taking 1 gram of salt per day, the blood sodium level maintained at normal range. Literature search identified no reports in Chinese journals, whereas 50 publications were found in English journals. A total of 30 NSIAD probands were reported and 16 of those (53%) had childhood onset, most presented with seizures. The majority had a hotspot change at the nucleotide position of 409 in AVPR2. Nine cases had an amino acid change as R137C and five cases as R137L. Fluid restriction and oral urea intake were main treatment options, no report so far was found with oral furosemide treatment. Conclusions: NSIAD presented with hyponatremia without any other specific presentations. Genetic testing for variants in AVPR2 is helpful for early diagnosis and timely treatment. The first two cases of oral furosemide treatment were reported by the article which helped to maintain a normal serum sodium level after limiting fluid intake and supplementing sodium which showed limited effect.


Asunto(s)
Hiponatremia , Receptores de Vasopresinas , Niño , Preescolar , China , Estudios de Seguimiento , Enfermedades Genéticas Ligadas al Cromosoma X , Humanos , Hiponatremia/diagnóstico , Hiponatremia/genética , Síndrome de Secreción Inadecuada de ADH , Lactante , Masculino , Mutación , Receptores de Vasopresinas/genética
6.
Zhonghua Er Ke Za Zhi ; 59(8): 678-683, 2021 Aug 02.
Artículo en Zh | MEDLINE | ID: mdl-34333921

RESUMEN

Objective: To investigate the clinical and genetic features, and treatment of X-linked hypophosphatemic rickets (XLH). Methods: In this retrospective study, we reviewed the medical records of 25 pediatric patients with XLH who were admitted to Department of Endocrinology Genetics and Metabolism,Beijing Children's Hospital from January 2010 to January 2020. The clinical characteristics, PHEX gene variants, as well as clinical outcome of the patients were summarized. To analyze the correlation between genotype and phenotype, the patients were divided into different subgroups according to the location of the variants, including N-terminal-located vs. C-terminal-located variant, and Zn-binding domain exon 17 or 19 variant vs. non-exon 17 or 19 variant. The age at onset, height standard deviation score (HtSDS), intercondylar or intermalleolar distance, fasting serum phosphorus, and HtSDS and intercondylar or intermalleolar distance at the final follow-up were compared by rank sum test or t text. Results: Among the 25 children with XLH, 8 were boys and 17 were girls. The median age of onset was 1.2 (1.0, 1.8) years, and the median age of diagnosis was 2.5 (1.5, 4.3) years. The main clinical manifestations were abnormal gait and lower limb deformity. The HtSDS was -2.0(-3.2, -0.8), and the intercondylar or intermalleolar distance was 4.5 (3.0, 6.0) cm. The fasting serum phosphorus level was 0.8 (0.7, 0.9) mmol/L, while the serum alkaline phosphatase level was (721±41) U/L and the serum calcium level was (2.5±0.1) mmol/L. Three patients (12%) had parathyroid hormone levels above the upper limit of the normal range. Twenty-five patients (100%) showed radiographic changes of active rickets. Nephrocalcinosis was found in 2 cases (9%). Twenty-four different PHEX variations were detected in 25 patients, among whom 11 (44%) had not been reported previously. No hot spot variation was found. No statistical differences (all P>0.05) were identified in clinical features and outcomes either in comparing patients with N-terminal (21 cases) and C-terminal (4 cases) variants, or in comparing patients with variant located in exon 17 or 19 (4 cases) or not (21 cases). Twenty-four cases (96%) were treated regularly with phosphate supplements and active vitamin D. After 2.7 (1.6, 5.0) years of follow-up, clinical symptoms were relieved in 96% (24/25) of the patients. The HtSDS after treatment had no significant difference compared to that before treatment (-2.0(-3.2, -0.8) vs.-2.0(-2.8, -1.1),Z =-0.156, P>0.05), while the intercondylar or intermalleolar distance after treatment was significantly reduced compared to that before treatment (4.5(3.0, 6.0) vs. 1.5(0, 3.3) cm, Z =-3.043, P<0.05). Bone X-rays were reexamined in 17 cases after treatment, and radiographic signs of rickets were improved. Eighteen cases had secondary hyperparathyroidism and 7 cases had nephrocalcinosis. Conclusions: The main clinical manifestations of XLH are abnormal gait, lower limb deformity and short stature. A high proportion of novel variations of PHEX gene but no hot spot variation neither genotype-phenotype correlation are found. Regular treatment with phosphate supplements and active vitamin D can significantly improve the symptoms except for the height. However, the rate of adverse events including secondary hyperparathyroidism and nephrocalcinosis seems to be high.


Asunto(s)
Raquitismo Hipofosfatémico Familiar , Enfermedades Genéticas Ligadas al Cromosoma X , Niño , Preescolar , Exones , Raquitismo Hipofosfatémico Familiar/genética , Femenino , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Humanos , Lactante , Masculino , Endopeptidasa Neutra Reguladora de Fosfato PHEX/genética , Fenotipo , Estudios Retrospectivos
7.
Science ; 163(3864): 280-2, 1969 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-5762605

RESUMEN

A physical model of nerve excitation and conduction is proposed based on the discovery of three new axon membrane properties: the negative fixed surface charge, the birefringence change, and the infrared emission.


Asunto(s)
Axones/fisiología , Membrana Celular/fisiología , Potenciales de la Membrana , Modelos Neurológicos , Modelos Estructurales , Conducción Nerviosa , Potenciales de Acción , Axones/citología , Birrefringencia , Rayos Infrarrojos
9.
Eur Rev Med Pharmacol Sci ; 23(12): 5441-5448, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31298397

RESUMEN

OBJECTIVE: Oxaliplatin has shown good anti-tumour activity in the treatment of tumours involving the digestive system. However, its application is limited because of severe neurotoxicity in some patients. The purpose of this study was to evaluate whether compound porcine cerebroside and ganglioside (CPCG) can reduce or prevent oxaliplatin-induced neurotoxicity. PATIENTS AND METHODS: Patients with digestive system tumour who received oxaliplatin-based chemotherapy were retrospectively divided into experimental and control groups according to the receipt of CPCG during chemotherapy. Adverse events at the end of each chemotherapy cycle were recorded. We compared the incidence of neurotoxicity between the two groups and graded the neurotoxicity symptoms using the Common Terminology Criteria for Adverse Events v5.0. RESULTS: The study included 115 patients (experimental group, 57; control group, 58). The number of chemotherapy cycles (6.65 vs. 6.41, p=0.540) and oxaliplatin dose (775.92 mg/m2 vs. 724.20 mg/m2, p=0.250) were comparable between the two groups. All patients developed grade 1 to 3 neurotoxicity; grade 4-5 neurotoxicity was not observed. The incidence of neurotoxicity and the probability of advanced neurotoxicity were significantly lower in the experimental group than in the control group (p<0.05). After a 6 to 18 months follow-up, the two groups showed no significant differences in the chemotherapy response and recurrence rate (p=0.846). CONCLUSIONS: CPCG reduces oxaliplatin-induced neurotoxicity without reducing the efficacy of oxaliplatin-based regimens; thus, it can be used for preventing oxaliplatin-induced neurotoxicity in patients with cancer.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Cerebrósidos/administración & dosificación , Gangliósidos/administración & dosificación , Neoplasias Gastrointestinales/terapia , Fármacos Neuroprotectores/administración & dosificación , Síndromes de Neurotoxicidad/epidemiología , Oxaliplatino/efectos adversos , Adulto , Anciano , Animales , Estudios de Casos y Controles , Quimioterapia Adyuvante/efectos adversos , Quimioterapia Adyuvante/métodos , China/epidemiología , Combinación de Medicamentos , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante/efectos adversos , Terapia Neoadyuvante/métodos , Síndromes de Neurotoxicidad/diagnóstico , Síndromes de Neurotoxicidad/etiología , Síndromes de Neurotoxicidad/prevención & control , Prevalencia , Índice de Severidad de la Enfermedad , Porcinos , Resultado del Tratamiento
10.
Food Chem Toxicol ; 45(6): 928-34, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17215065

RESUMEN

The N-nitroso derivative of an extensively used insecticide, propoxur, consistently induced dose-responsive chromosome aberrations and sister-chromatid exchanges (SCEs) in Chinese hamster ovary (CHO-W8) cells. Further investigations indicated that post-treatment incubation with a regular 1.5-cell-cycle period did not offer an unbiased estimation of the genotoxicity of N-nitroso carbamate insecticides. The scale of chromosome aberration induction increased with extension of the post-treatment incubation period. Comparable phenomena were not found in CHO-AGT cells proficient for O(6)-methylguanine-DNA-methyltransferase. In CHO-W8 cells, pulsed-treatment of the insecticide in the 1st replication cycle showed higher SCE induction than in the 2nd cycle. Similar phenomenon was also found in SCE induced by N-nitroso derivatives from other carbamate insecticides including aldicarb, carbofuran and methomyl. Treated cells did not show significantly perturbed cell cycle progression until 12 h after treatment removal. Based on the above observations, the O(6)-methylguanine-DNA adduct is suggested to be the major lesion caused by the delayed genotoxic effect of N-methyl carbamate insecticides as described in this report.


Asunto(s)
Aberraciones Cromosómicas/inducido químicamente , Insecticidas/toxicidad , Mutágenos/toxicidad , Propoxur/toxicidad , Intercambio de Cromátides Hermanas/efectos de los fármacos , Animales , Células CHO , Ciclo Celular/efectos de los fármacos , Cricetinae , Cricetulus , Citometría de Flujo
11.
J Gen Physiol ; 108(4): 295-313, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8894978

RESUMEN

Multidrug resistance (MDR) mediated by overexpression of the MDR protein (P-glycoprotein) has been associated with intracellular alkalinization, membrane depolarization, and other cellular alterations. However, virtually all MDR cell lines studied in detail have been created via protocols that involve growth on chemotherapeutic drugs, which can alter cells in many ways. Thus it is not clear which phenotypic alterations are explicitly due to MDR protein overexpression alone. To more precisely define the MDR phenotype mediated by hu MDR 1 protein, we co-transfected hu MDR 1 cDNA and a neomycin resistance marker into LR73 Chinese hamster ovary fibroblasts and selected stable G418 (geneticin) resistant transfectants. Several clones expressing different levels of hu MDR 1 protein were isolated. Unlike previous work with hu MDR 1 transfectants, the clones were not further selected with, or maintained on, chemotherapeutic drugs. These clones were analyzed for chemotherapeutic drug resistance, intracellular pH (pHi), membrane electrical potential (Vm), and stability of MDR 1 protein overexpression. LR73/hu MDR 1 clones exhibit elevated pHi and are depolarized, consistent with previous work with LR73/mu MDR 1 transfectants (Luz, J.G. L.Y. Wei, S. Basu, and P.D. Roepe. 1994. Biochemistry. 33:7239-7249). The extent of these perturbations is related to the level of hu MDR 1 protein that is expressed. Cytotoxicity experiments with untransfected LR73 cells with elevated pHi due to manipulating percent CO2 show that the pHi perturbations in the MDR 1 clones can account for much of the measured drug resistance. Membrane depolarization in the absence of MDR protein expression is also found to confer mild drug resistance, and we find that the pHi and Vm changes can conceivably account for the altered drug accumulation measured for representative clones. These data indicate that the MDR phenotype unequivocally mediated by MDR 1 protein overexpression alone can be fully explained by the perturbations in Vm and pHi that accompany this overexpression. In addition, MDR mediated by MDR protein overexpression alone differs significantly from that observed for MDR cell lines expressing similar levels of MDR protein but also exposed to chemotherapeutic drugs.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Resistencia a Múltiples Medicamentos , Hidrógeno/metabolismo , Transfección , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Bicarbonatos/farmacología , Células CHO/efectos de los fármacos , Células CHO/metabolismo , Células CHO/fisiología , Cricetinae , Humanos , Concentración de Iones de Hidrógeno , Potenciales de la Membrana
12.
Dalton Trans ; 44(40): 17841-9, 2015 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-26399298

RESUMEN

Hybrid halide perovskites represent one of the most promising solutions toward the fabrication of all solid nanostructured solar cells, with improved efficiency and long-term stability. This article aims at investigating the properties of CH3NH3PbI3 with controlled loading time in CH3NH3I solution via a two-step sequential deposition and correlating them with their photovoltaic performances. It is found that the optimum PCE of the loading time in the CH3NH3I solution is possible only at a relatively short time (10 min). Prolonging the loading time will degrade the perovskite film, and deteriorate the device performance by introducing a large amount of excessive defects and recombination. However, even if the material band gap remains substantially unchanged, a suitable loading time can dramatically improve the charge transport within the perovskite layer, exhibiting the out-standing performances of meso-superstructured solar cells.

13.
Microsc Res Tech ; 36(5): 380-1, 1997 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-9140939

RESUMEN

This paper summarizes methods conventionally used to prepare thin foil samples of powder materials for transmission electron microscopy (TEM) and introduces another variant, ultramicrotomy, for the preparation of TEM samples of industrial dust powder. The choice of ultramicrotoming in the present work was based on two features of this technique: (1) it can produce thin-sectioned specimens with a uniform thickness; (2) it can retain the original elemental distribution in phases of the sample during sectioning. Dust powder preparation and the sectioning procedure are described in this paper. The results of the method are illustrated by examples of TEM/STEM micrographs of industrial dust.


Asunto(s)
Microscopía Electrónica/métodos , Microtomía , Polvos
14.
Microsc Res Tech ; 45(3): 198-202, 1999 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-10344771

RESUMEN

The objective of this work was to prepare for transmission electron microscopy (TEM) a layered structure of materials with fragile microstructure. The samples consisted of two layers of different materials, silicon nitride and borosilicate glass, loosely bonded together. The low strength of the sample resulted in fragmentation during more conventional preparation. However, it was possible to prepare the fragments by mounting them in a titanium specimen carrier with aluminium strips as support. After grinding and polishing, a technique of low-angle ion milling was used to obtain electron beam transparent areas at the nitride/glass interface.


Asunto(s)
Adhesión del Tejido/métodos , Microscopía Electrónica/métodos
15.
Environ Mol Mutagen ; 29(4): 386-93, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9212790

RESUMEN

Three carbamate insecticides (propoxur, methomyl, and aldicarb) were evaluated for their ability to induce micronuclei (MN) in vitro using cultured Chinese hamster ovary (CHO) cells, and in vivo in mouse bone marrow erythrocytes. In vitro, all three insecticides induced a significant increase in micronucleated binucleate cells, which was generally both dose and sample time dependent. The in vivo studies involved treating male BALB/c mice by different routes, either once or on 3 consecutive days, followed by multiple or single sampling. Treatment by intraperitoneal injection or oral gavage induced a significant increase in micronucleated reticulocytes (MNRETs) in peripheral blood. For all three chemicals, the MN response depended on sample time and the number of treatments, while for aldicarb, the response depended also on the route of exposure. These positive results demonstrate that propoxur, methomyl, and aldicarb are capable of inducing structural and/or numerical chromosomal aberrations in mammalian cells either in vitro or in vivo. Furthermore, based on the results obtained, on optimal in vivo MN protocol for carbamate insecticides is a single treatment followed by blood sampling at 24 and 48 hr after treatment.


Asunto(s)
Aldicarb/toxicidad , Metomil/toxicidad , Pruebas de Micronúcleos/métodos , Propoxur/toxicidad , Aldicarb/administración & dosificación , Animales , Células CHO/efectos de los fármacos , Cricetinae , Relación Dosis-Respuesta a Droga , Eritrocitos/efectos de los fármacos , Insecticidas/administración & dosificación , Insecticidas/toxicidad , Masculino , Metomil/administración & dosificación , Ratones , Ratones Endogámicos BALB C , Mitomicinas/toxicidad , Propoxur/administración & dosificación , Reticulocitos/efectos de los fármacos , Factores de Tiempo
16.
Mutat Res ; 444(1): 167-74, 1999 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-10477351

RESUMEN

Two organotin pesticides, triphenyltin acetate (TPTA) and triphenyltin hydroxide (TPTH), were evaluated for their ability to induce micronuclei (MN) and sister chromatid exchange (SCE) in vitro using cultured Chinese hamster ovary (CHO) cells and in vivo BALB/c mouse erythrocytes. Both pesticides induced a dose-dependent increase but only TPTH induced a significant increase in MN at the highest dose (150 ng/ml) tested in CHO cells. With adding S9 microsomal fractions, both pesticides induced a meaningful MN induction at 150 ng/ml and a dose-dependent significant increase in SCE. In vivo MN induction in erythrocytes was conducted by treating BALB/c mice orally or intraperitoneally with these pesticides either in a single or triple treatments. Oral gavage (p.o.) of TPTA resulted in a dose-related significant increase of MN induction in peripheral blood and of TPTH induced a significant increase in micronucleated reticulocyte (MNRETs) only in a single treatment. Intraperitoneal administration of TPTA or TPTH, however, resulted in meaningless random increases in MN though these increases might be attributable to toxic effects. The MNRETs levels in the treatment with both pesticides were independent to the sampling time. This study demonstrated that TPTA and TPTH was potential chromosome mutagens.


Asunto(s)
Mutágenos/toxicidad , Compuestos Orgánicos de Estaño/toxicidad , Animales , Biotransformación , Células CHO , Cricetinae , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Fungicidas Industriales/farmacocinética , Fungicidas Industriales/toxicidad , Técnicas In Vitro , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Pruebas de Micronúcleos , Compuestos Orgánicos de Estaño/farmacocinética , Ratas , Intercambio de Cromátides Hermanas/efectos de los fármacos
17.
Ultramicroscopy ; 92(3-4): 285-92, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12213030

RESUMEN

The energy loss near edge structure (ELNES) of many elements is strongly influenced by the presence of oxygen or other elements at surfaces, grain boundaries, or in the bulk material. The presented investigation deals mainly with the influence of oxygen at the surface. A method for the separation of both, the pure bulk signal and the oxidized surface signal, was evaluated and tested on Al, Cu, Mg, and Si. A comparison of experimental data with ab initio bandstructure calculations and other proofs of the accuracy of ELNES separation are presented. Influences of error propagations were tested and are exemplarily given for Al and Si.

18.
Biotech Histochem ; 79(1): 45-52, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15223753

RESUMEN

Insufficient dietary magnesium (Mg) intake has been associated with low bone mass in humans,and recent basic science studies have indicated that this bone loss may be secondary to increased release of substance P and TNFc Much less is known about the effects of low Mg intake on cartilage. We have evaluated growth plate and articular cartilage in rats following a 6 month dietary Mg restriction. Histomorphometry demonstrated significantly decreased distal femur articular cartilage chondrocyte density and decreased tibial growth plate width in experimental animals compared to controls. Growth plates of Mg-restricted animals showed reduced chondrocyte column formation. Extracellular matrix of both articular cartilage and growth plates in experimental animals contained reduced amounts of proteoglycans. Immunolocalization of Sox9 was decreased in both articular and growth plate cartilage in experimental animals compared to controls, suggesting that reduced Mg intake causes cartilage changes that may be secondary to reduced levels of the SOX9 transcription factor.


Asunto(s)
Cartílago Articular/patología , Placa de Crecimiento/patología , Proteínas del Grupo de Alta Movilidad/metabolismo , Deficiencia de Magnesio/metabolismo , Deficiencia de Magnesio/patología , Factores de Transcripción/metabolismo , Alimentación Animal , Animales , Peso Corporal/efectos de los fármacos , Cartílago Articular/efectos de los fármacos , Cartílago Articular/metabolismo , Placa de Crecimiento/efectos de los fármacos , Placa de Crecimiento/metabolismo , Inmunohistoquímica , Ratas , Ratas Sprague-Dawley , Factor de Transcripción SOX9
19.
Am J Chin Med ; 7(1): 53-75, 1979.
Artículo en Inglés | MEDLINE | ID: mdl-217263

RESUMEN

In this paper we present scientific advance in acupuncture based on electrical, neurophysiological, biochemical and therapeutic studies made inside and outside China since the early fifties. New modalities other than traditional needling techniques notably developed in Japan, France and Germany are described. For future prospects, efforts by making use of systems approach, field-body interaction, self-defense self-strategy and circadian rhythm are likely to produce great fruition in medicine. Possibilities of making advances in "three P's" medicine (preventive medicine, precision medicine and people medicine) by acupuncture are discussed.


Asunto(s)
Terapia por Acupuntura , Terapia por Acupuntura/métodos , Animales , Fenómenos Fisiológicos Sanguíneos , Sistema Nervioso Central/fisiología , Endorfinas/fisiología , Potenciales Evocados , Humanos , Recuento de Leucocitos , Dolor/fisiopatología , Manejo del Dolor , Conejos , Transmisión Sináptica
20.
J Med Eng Technol ; 9(4): 183-6, 1985.
Artículo en Inglés | MEDLINE | ID: mdl-4045986

RESUMEN

An electronic diagnoser of the arterial pulse has been designed to give three outputs: pulse amplitude, instantaneous pulse rate (IPR) and spectral energy ratios (SER) at 5 and 10 Hz. The information thus provided will be useful for diagnosing many kinds of disease in the human body.


Asunto(s)
Electrónica Médica/instrumentación , Pulso Arterial , Diseño de Equipo , Humanos , Transductores de Presión
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