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1.
Npj Flex Electron ; 7(1): 14, 2023.
Article in English | MEDLINE | ID: mdl-38665150

ABSTRACT

Transient electronics offer a promising solution for reducing electronic waste and for use in implantable bioelectronics, yet their fabrication remains challenging. We report on a scalable method that synergistically combines chemical and photonic mechanisms to sinter printed Zn microparticles. Following reduction of the oxide layer using an acidic solution, zinc particles are agglomerated into a continuous layer using a flash lamp annealing treatment. The resulting sintered Zn patterns exhibit electrical conductivity values as high as 5.62 × 106 S m-1. The electrical conductivity and durability of the printed zinc traces enable the fabrication of biodegradable sensors and LC circuits: temperature, strain, and chipless wireless force sensors, and radio-frequency inductive coils for remote powering. The process allows for reduced photonic energy to be delivered to the substrate and is compatible with temperature-sensitive polymeric and cellulosic substrates, enabling new avenues for the additive manufacturing of biodegradable electronics and transient implants.

2.
J Obstet Gynaecol ; 42(4): 580-586, 2022 May.
Article in English | MEDLINE | ID: mdl-34486910

ABSTRACT

In this prospective study on vitamin D and its associated factors conducted on 256 pregnant women from Anambra state of southeastern Nigeria, Vitamin D deficiency (VDD) occurred in 36 (14.1%). Vitamin D levels were significantly associated with parity, gestational age, social class, place of abode, skin colour, workplace location, and compliance to ANC drugs. Pregnant women with these features are considered to be at risk for vitamin D deficiency. The study however did not show any association between vitamin D and maternal age, social class of the pregnant women, and the season of the year. It is recommended that vitamin D supplementation be considered routinely for women with the risk factors - especially for the grandmultipara, women at term gestational age, women of dark complexion, those with indoor work location, and of urban habitat.Impact statementWhat is already known on this subject? Vitamin D is a fat-soluble vitamin primarily responsible for calcium and phosphorous homeostasis in the human body. it is derived in the human body both from endogenous sources through cutaneous synthesis following exposure to sunlight, and from endogenous conversion from pre-vitamin D to 25-hdroxycholecalciferol (25 (OH)D. Vitamin D is essential in pregnancy for maternal health, foetal skeletal growth and bone development. Vitamin D deficiency (VDD) in pregnancy occurs globally with a prevalence of 4.7% to as high as 80%.What do the results of this study add? This study shows that parity, gestational age, social class, place of domicile, skin colour, workplace location, and compliance to ANC drugs constitutes associated factors to vitamin D levels.What are the implications of these findings for clinical practice and/or further research? These findings imply that grandmultiparous pregnant women, women at term gestational age, of dark complexion, with indoor work location, and of urban habitat, by virtue of their relatively lower levels of vitamin D, should be considered for routine vitamin D supplementation.


Subject(s)
Pregnancy Complications , Vitamin D Deficiency , Female , Humans , Nigeria/epidemiology , Pregnancy , Pregnancy Complications/epidemiology , Pregnant Women , Prospective Studies , Vitamin D , Vitamin D Deficiency/epidemiology , Vitamins
3.
Gynecol Oncol Rep ; 38: 100860, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34632035

ABSTRACT

This is a comparative study on the adequacy of cervical smears obtained using the Papcone® sampling device or wooden Ayre's spatula conducted from two tertiary health facilities -- Nnamdi Azikiwe University Teaching Hospital Nnewi and Chukwuemeka Odumegwu Ojukwu University Teaching Hospital Awka, in Anambra State, Nigeria. Slides from smears obtained using both devices were read by a cytopathologist blinded for the study. The primary outcome was the proportion of smears with an adequate endocervical component. Significantly higher adequate cervical smears were obtained in 177/192 (92.2%) women using the Papcone® sampling device, compared to 152/192 (79.2%) using wooden Ayre's spatula (p < 0.001). Kappa analysis showed moderate inter-rater agreement between the two devices. We recommend the use of the Papcone device when it is available, as the adequacy of cervical smears obtained with the Papcone® was better than that obtained using wooden Ayre's spatula.

4.
Article in English | WPRIM (Western Pacific) | ID: wpr-900484

ABSTRACT

Palmar fibromatosis (Dupuytren disease/contracture) is the most common type of fibromatosis, defined as a benign proliferation of fibroblasts and myofibroblasts. The disease process is most common in white, middle-aged and older men occurring at the distal palmar crease leading to nodules and contracture, which in many cases recur after surgical treatment. In a similar process, plantar fibromatosis (Ledderhose disease) is a proliferation of fibroblasts and myofibroblasts on the plantar aponeurosis of mostly middle-aged patients that may lead to painful nodules but usually does not lead to contracture. Both processes are histologically similar, composed of a bland cellular proliferation of spindle cells with a bluish appearance and with a variable amount of background collagen, depending on the age of the lesion. The etiology of both lesions is still uncertain, while treatment ranges from observation to surgery, with some pharmacologic agents being investigated with mixed success. In this paper we provide an overview of both processes with regards to clinical and radiologic findings, pathophysiology, diagnosis, treatment, and prognosis.

5.
Article in English | WPRIM (Western Pacific) | ID: wpr-892780

ABSTRACT

Palmar fibromatosis (Dupuytren disease/contracture) is the most common type of fibromatosis, defined as a benign proliferation of fibroblasts and myofibroblasts. The disease process is most common in white, middle-aged and older men occurring at the distal palmar crease leading to nodules and contracture, which in many cases recur after surgical treatment. In a similar process, plantar fibromatosis (Ledderhose disease) is a proliferation of fibroblasts and myofibroblasts on the plantar aponeurosis of mostly middle-aged patients that may lead to painful nodules but usually does not lead to contracture. Both processes are histologically similar, composed of a bland cellular proliferation of spindle cells with a bluish appearance and with a variable amount of background collagen, depending on the age of the lesion. The etiology of both lesions is still uncertain, while treatment ranges from observation to surgery, with some pharmacologic agents being investigated with mixed success. In this paper we provide an overview of both processes with regards to clinical and radiologic findings, pathophysiology, diagnosis, treatment, and prognosis.

6.
Journal of Gastric Cancer ; : 313-327, 2020.
Article | WPRIM (Western Pacific) | ID: wpr-835763

ABSTRACT

Purpose@#Nodal downstaging after preoperative therapy for gastric cancer has been shown to impart excellent prognosis, but this has not been validated in a national cohort. The role of neoadjuvant chemoradiation (NACR) in nodal downstaging remains unclear when compared with that of neoadjuvant chemotherapy alone (NAC). Furthermore, it is unknown whether the prognostic implications of nodal downstaging differ by preoperative regimen. @*Materials and Methods@#Using the National Cancer Database, overall survival (OS) duration was compared among natural N0 (cN0/ypN0), downstaged N0 (cN+/ypN0), and nodepositive (ypN+) gastric cancer patients treated with NACR or NAC. Factors associated with nodal downstaging were examined in a propensity score-matched cohort of cN+ patients, matched 1:1 by receipt of NACR or NAC. @*Results@#Of 7,426 patients (natural N0 [n=1,858, 25.4%], downstaged N0 [n=1,813, 24.4%], node-positive [n=3,755, 50.4%]), 58.2% received NACR, and 41.9% received NAC. The median OS durations of downstaged N0 (5.1 years) and natural N0 (5.6 years) patients were similar to one another and longer than that of node-positive patients (2.1 years) (P<0.001). In the matched cohort of cN+ patients, more recent diagnosis (2010–2015 vs. 2004–2009) (odds ratio [OR], 2.57; P<0.001) and NACR (OR, 2.02; P<0.001) were independently associated with nodal downstaging. The 5-year OS rate of downstaged N0 patients was significantly lower after NACR (46.4%) than after NAC (57.7%) (P=0.003). @*Conclusions@#Downstaged N0 patients have the same prognosis as natural N0 patients.Nodal downstaging occurred more frequently after NACR; however, the survival benefit of nodal downstaging after NACR may be less than that when such is achieved by NAC.

7.
Br J Anaesth ; 121(6): 1249-1259, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30442252

ABSTRACT

BACKGROUND: Severe sepsis has a high mortality rate. There is increasing evidence that human mesenchymal stem cells possess immunomodulatory properties in sepsis, particularly those from adipose tissue. We hypothesised that micro-fragmented human fat, obtained with minimal alteration of the stromal vascular niche, attenuates the inflammatory response and improves outcome in a murine model of sepsis. METHODS: Micro-fragmented fat, lipoaspirate, or saline was administered intraperitoneally 2 h after caecal ligation and puncture (CLP) in C57Bl/6RJ ketamine-xylazine anaesthetised mice. The primary endpoint was the inflammatory score. Secondary endpoints included survival, physiological, histological, and biological parameters. RESULTS: In CLP mice, micro-fragmented fat administration significantly decreased the median (range) inflammatory score compared with saline [17 (14-20) vs 9 (8-12), P=0.006]. Secondary endpoints were also significantly improved in micro-fragmented fat-treated compared with saline-treated CLP mice. Improvement in inflammatory score and in survival was suppressed when micro-fragmented fat was co-administered with liposomes loaded with clodronate (macrophage toxin) or NS-398 (cyclo-oxygenase 2 inhibitor), but not with SC-560 (cyclo-oxygenase 1 inhibitor). CONCLUSIONS: In a murine model of severe sepsis, micro-fragmented fat improved early inflammatory status and outcome, at least in part, by a cyclo-oxygenase-2-mediated mechanism. The potential therapeutic value of micro-fragmented fat in severe sepsis warrants further investigation.


Subject(s)
Adipose Tissue/transplantation , Inflammation/prevention & control , Sepsis/complications , Acute Disease , Animals , Disease Models, Animal , Injections , Male , Mice , Mice, Inbred C57BL
8.
Nat Commun ; 6: 10145, 2015 Dec 15.
Article in English | MEDLINE | ID: mdl-26666572

ABSTRACT

Sepsis, or systemic inflammatory response syndrome, is the major cause of critical illness resulting in admission to intensive care units. Sepsis is caused by severe infection and is associated with mortality in 60% of cases. Morbidity due to sepsis is complicated by neuromyopathy, and patients face long-term disability due to muscle weakness, energetic dysfunction, proteolysis and muscle wasting. These processes are triggered by pro-inflammatory cytokines and metabolic imbalances and are aggravated by malnutrition and drugs. Skeletal muscle regeneration depends on stem (satellite) cells. Herein we show that mitochondrial and metabolic alterations underlie the sepsis-induced long-term impairment of satellite cells and lead to inefficient muscle regeneration. Engrafting mesenchymal stem cells improves the septic status by decreasing cytokine levels, restoring mitochondrial and metabolic function in satellite cells, and improving muscle strength. These findings indicate that sepsis affects quiescent muscle stem cells and that mesenchymal stem cells might act as a preventive therapeutic approach for sepsis-related morbidity.


Subject(s)
Mesenchymal Stem Cell Transplantation , Mitochondria, Muscle/metabolism , Satellite Cells, Skeletal Muscle/pathology , Sepsis/complications , Stem Cells/pathology , Animals , Cells, Cultured , Cytokines/genetics , Cytokines/metabolism , Gene Expression Regulation , Male , Mice , Mice, Transgenic , Peritonitis/complications , Reactive Oxygen Species/metabolism , Regeneration , Sepsis/metabolism , Stem Cells/metabolism
9.
Biomed Microdevices ; 17(4): 77, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26153517

ABSTRACT

This work presents a planar, longitudinal mode ultrasonic scalpel microfabricated from monocrystalline silicon wafers. Silicon was selected as the material for the ultrasonic horn due to its high speed of sound and thermal conductivity as well as its low density compared to commonly used titanium based alloys. Combined with a relatively high Young's modulus, a lighter, more efficient design for the ultrasonic scalpel can be implemented which, due to silicon batch manufacturing, can be fabricated at a lower cost. Transverse displacement of the piezoelectric actuators is coupled into the planar silicon structure and amplified by its horn-like geometry. Using finite element modeling and experimental displacement and velocity data as well as cutting tests, key design parameters have been identified that directly influence the power efficiency and robustness of the device as well as its ease of controllability when driven in resonance. Designs in which the full- and half-wave transverse modes of the transducer are matched or not matched to the natural frequencies of the piezoelectric actuators have been evaluated. The performance of the Si micromachined scalpels has been found to be comparable to existing commercial titanium based ultrasonic scalpels used in surgical operations for efficient dissection of tissue as well as coaptation and coagulation of tissue for hemostasis. Tip displacements (peak-to-peak) of the scalpels in the range of 10-50 µm with velocities ranging from 4 to 11 m/s have been achieved. The frequency of operation is in the range of 50-100 kHz depending on the transverse operating mode and the length of the scalpel. The cutting ability of the micromachined scalpels has been successfully demonstrated on chicken tissue.


Subject(s)
Dissection/instrumentation , Silicon/chemistry , Surgical Instruments , Ultrasonics/instrumentation , Animals , Chickens , Electric Impedance , Equipment Design , Finite Element Analysis , Hemostasis , Materials Testing , Reproducibility of Results , Swine , Transducers
10.
Rev Sci Instrum ; 84(10): 103703, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24182115

ABSTRACT

A scanning thermal microscope working in passive mode using a micronic thermocouple probe is presented as a quantitative technique. We show that actual surface temperature distributions of microsystems are measurable under conditions for which most of usual techniques cannot operate. The quantitative aspect relies on the necessity of an appropriate calibration procedure which takes into account of the probe-to-sample thermal interaction prior to any measurement. Besides this consideration that should be treated for any thermal contact probing system, the main advantages of our thermal microscope deal with the temperature available range, the insensitivity to the surface optical parameters, the possibility to image DC, and AC temperature components up to 1 kHz typically and a resolution limit related to near-field behavior.

11.
Article in English | MEDLINE | ID: mdl-23082598

ABSTRACT

Nigeria has restrictive abortion laws; unsafe abortion and its complications are major public health challenges. Access to reproductive health services in Nigeria, including medical abortion, is poor. We determined the socio-demographic characteristics, patterns of abortion practices, and experiences of medical abortions among abortion seekers in southeastern Nigeria. We carried out a descriptive, cross sectional survey of 100 consecutive medical abortion seekers in southeastern Nigeria. Subjects had a mean age of 23.5 + 4.4 years. Fifty-five percent of respondents were students. Sixty-four percent had a secondary educational level, 33% had a tertiary education level and 3% had a primary educational level. Fifty-eight percent of subjects were ages 18-20 years at coitarche; 25% had one or more previous deliveries and 49% had a previous termination of pregnancy. Forty-eight percent had used drugs for pregnancy terminations. Drugs used for termination included quinine combined with other drugs in 8%; gynaecosid alone in 6%, gynaecosid combined with other drugs in 6% menstrogen combined with other drugs in 6% and an unclassified drug in 14%. Thirty-three percent of subjects purchased their abortion drugs in a pharmacy. Three percent, 2%, and 0% of subjects had a knowledge of misoprostol, mifepristone and methotrexate, respectively. One percent of respondents had used misoprostol. We detected serious information gaps regarding abortion and poor access to reproductive health services. There is a need for policies and program to bridge this gap, and a need for revision of the present Nigerian abortion law.


Subject(s)
Abortion, Induced/methods , Abortion, Induced/psychology , Health Knowledge, Attitudes, Practice , Abortifacient Agents, Steroidal/therapeutic use , Adolescent , Adult , Cross-Sectional Studies , Educational Status , Female , Health Services Accessibility , Humans , Nigeria , Pregnancy , Socioeconomic Factors
12.
Niger J Med ; 20(1): 20-7, 2011.
Article in English | MEDLINE | ID: mdl-21970255

ABSTRACT

Gender, for its impact on virtually every contemporary life issue, can rightly be regarded as a foremost component of reproductive health. Reproductive health basically emphasises on people and their rights to sexuality, reproduction, and family planning, and the information to actualize these right, which has been inextricably linked to development at the International Conference on Population and Development (ICPD) held in Cairo, Egypt, in 1994. Women's sexual and reproductive rights became recognised as universal human right, violations of which occur in some reproductive health areas including gender concerns. Gender inequality and inequity encompass gender based violence as well as gender discrimination which cuts across the life cycle of the woman; attitudes, religious and cultural practices of various nations; and issues related to employment, economy, politics, and development. The redress of gender inequality is a collective responsibility of nations and supranational agencies. Nations should adopt a framework hinged on three pedestals--legal, institutional and policy, employing the three recommended approaches of equal treatment, positive action, and gender mainstreaming.


Subject(s)
Reproductive Health , Reproductive Rights , Women's Rights , Domestic Violence , Female , Gender Identity , Humans , Interpersonal Relations , Prejudice
13.
West Afr J Med ; 30(1): 35-41, 2011.
Article in English | MEDLINE | ID: mdl-21863587

ABSTRACT

BACKGROUND: Effective maternal and child healthcare delivery requires a proper and adequate funding of the health sector. OBJECTIVE: To determine the effect of government-community healthcare co-financing on maternal and child healthcare services' delivery. METHODS: A descriptive, cross-sectional study with an intervention component, conducted amongst 240 women from Igboukwu (intervention area), and Ekwuluobia (control area), of Anambra State of Nigeria. RESULTS: The biosocial characteristics of the respondents were essentially similar. Better utilization of health services occurred in the intervention area post-intervention. Quality of service from intervention clients' perspective showed significant improvement post-intervention. Distance less than five km, transportation cost less than N40, and maternal education above secondary level impacted positively on utilization of maternal and child health services. Acceptability of the scheme was better for the intervention facility evident from the higher number of respondents showing "willingness to join", and "willingness to pay". CONCLUSION: Health sector funding partnership, positively impacts on maternal and child health services. Government's total commitment, backed with legislation, and community mobilization, will sustain the scheme.


Subject(s)
Child Health Services/economics , Community Health Planning/organization & administration , Financing, Government/economics , Insurance, Health/economics , Maternal Health Services/statistics & numerical data , Adolescent , Adult , Child , Child Health Services/statistics & numerical data , Cross-Sectional Studies , Delivery of Health Care , Female , Focus Groups , Humans , Maternal Health Services/economics , Nigeria , Patient Acceptance of Health Care , Qualitative Research , Quality of Health Care , Socioeconomic Factors , Young Adult
14.
Anal Chim Acta ; 688(2): 175-82, 2011 Mar 04.
Article in English | MEDLINE | ID: mdl-21334483

ABSTRACT

This paper presents the optimization of a micro gas preconcentrator based on a micro-channel in porous and non-porous silicon filled with an adequate adsorbent. This micro gas preconcentrator is both applicable in the fields of atmospheric pollution monitoring (Volatil organic compounds--VOCs) and explosives detection (nitroaromatic compounds). Different designs of micro-devices and adsorbent materials have been investigated since these two parameters are of importance in the performances of the micro-device. The optimization of the device and its operation were driven by its future application in outdoor environments. Parameters such as the preconcentration factor, cycle time and the influence of the humidity were considered along the optimization process. As a result of this study, a preconcentrator with a total cycle time of 10 min and the use of single wall carbon nanotubes (SWCNTs) as adsorbent exhibits a good preconcentration factor for VOCs with a limited influence of the humidity. The benefits of using porous silicon to modify the gas desorption kinetics are also investigated.

15.
Radiat Prot Dosimetry ; 100(1-4): 297-300, 2002.
Article in English | MEDLINE | ID: mdl-12382882

ABSTRACT

Miniature LiF:Mg,Ti (MTS-N) pellets, specially designed for dosimetry in proton radiotherapy, were studied in the 85-550 K temperature range. TL glow curves for differently Mg- or Ti-doped detectors were recorded, showing the preponderant influence of Mg concentration on the intensity of peak 5. The presence of a three-peak complex was also confirmed near 140 K; spectral emission of this peak consists of two bands whose maxima occur at 290 and 420 nm. TSEE glow curves above 300 K similar to those of TL were observed. The behaviour of TSEE and TL peak 5 following an X ray exposure from 33 to 500 Gy was studied: its intensity is a linear function of air kerma in both cases.


Subject(s)
Fluorides/radiation effects , Lithium Compounds/radiation effects , Thermoluminescent Dosimetry/methods , Fluorides/chemistry , Hot Temperature , Humans , Lithium Compounds/chemistry , Magnesium/chemistry , Proton Therapy , Radiochemistry , Radiotherapy Dosage , Spectrophotometry , Thermoluminescent Dosimetry/statistics & numerical data , Titanium/chemistry , X-Rays
16.
Radiat Prot Dosimetry ; 100(1-4): 329-32, 2002.
Article in English | MEDLINE | ID: mdl-12382890

ABSTRACT

An investigation of the thermoluminescence (TL) properties of high pressure, high temperature (HPHT) synthetic diamond crystals grown under diluted nickel or cobalt as solvent catalysts is reported. After a study of TL properties of 6 different samples, it is shown that a crystal grown with Ni+2%Ti and annealed at 2100 K presents an intense glow peak at around 490 K. This peak is characterised by a broad emission band centred at 530 nm (2.34 eV). This crystal presents a significant, reproducible and linear TL response relative to the absorbed dose up to an X ray air kerma of 10 Gy. All these features make this material suitable for ionising radiation dosimetry. A similar study is made on another crystal grown from pure Co, and a comparative review of the results does show that for dosimetry work, Ni-containing diamonds are more appropriate than those grown from Co catalyst.


Subject(s)
Diamond/radiation effects , Thermoluminescent Dosimetry/methods , Cobalt/chemistry , Crystallization , Diamond/chemistry , Hot Temperature , Luminescent Measurements , Nickel/chemistry , Pressure , Radiochemistry , Spectrophotometry , X-Rays
17.
Radiat Prot Dosimetry ; 100(1-4): 365-8, 2002.
Article in English | MEDLINE | ID: mdl-12382899

ABSTRACT

The luminescent properties of cerium doped calcium sulphate are studied: fluorescence and excitation spectra, optical absorption and thermoluminescence (TSL). It is known that, in rare earth doped CaSO4, only cerium induces a strong 400 degrees C TSL peak. In CaSO4:0.2%Ce samples synthesised under oxidising conditions, the recovery step of Ce3+ fluorescence is correlated with the 400 degrees C TSL peak readout, as mentioned by Nair er al. Our results indicate that an oxidation of Ce3+ ion does occur under X-irradiation (Ce3+ --> Ce4+), followed by a complete return to the trivalent state after thermal annealing at about 500 degrees C; our results confirm the hypothesis of Nair et al that Ce3+ ions are oxidised by ionising irradiation. So, a pure redox reaction seems the most probable for the 400 degrees C TSL peak of CaSO4:Ce. Moreover, the use of the 400 degrees C TSL peak for high temperature dosimetry applications is discussed.


Subject(s)
Calcium Sulfate/radiation effects , Thermoluminescent Dosimetry/methods , Calcium Sulfate/chemistry , Cerium/chemistry , Luminescent Measurements , Optics and Photonics , Radiochemistry , Spectrophotometry
18.
West Afr J Med ; 21(3): 244-7, 2002.
Article in English | MEDLINE | ID: mdl-12744579

ABSTRACT

An evaluation of various laboratory detection methods and characteristics of Gardnerella vaginalis was made using high vaginal swab samples of 470 out patient clinic--attending women. Gram stain for 'clue cells' showed positive results in 118 (25.1%)cases; culture, in 100 cases, (213%) and Amine Odour (213%), in 26 cases 5.5%, Majority, 71 cases, of the culture-positive results were associated with a pH value of 6 to 7. Gardnerella vaginalis grew predominantly in enriched culture media: Modified peptone-starch dextrose blood agar used for primary culture of organism, and also proteose peptone broth + cooked meat; Brain-heart infusion broth + 5% human serum; Brain heart infusion starch agar + 5% blood, and chocolate agar. Gardnerella vaginalis culture-positive samples also exhibited positive biochemical reactions with the hydrolysis of starch sensitivity to Bacitracin and 50 microg metronidazole, and haemolysis on human blood agar. Carbohydrate fermentation test was positive for all culture-positive cases, 100% for starch and maltose only, and negative for all the cases, 0% for Mannitol and glycerol.


Subject(s)
Bacteriological Techniques/methods , Clinical Laboratory Techniques/standards , Gardnerella vaginalis , Vaginosis, Bacterial/diagnosis , Vaginosis, Bacterial/microbiology , Bacteriological Techniques/standards , Biochemistry/methods , Biochemistry/standards , Culture Media/standards , Female , Gentian Violet , Hemolysis , Humans , Hydrogen-Ion Concentration , Hydrolysis , Nigeria , Phenazines , Sensitivity and Specificity , Vaginal Smears
19.
Biochem Pharmacol ; 55(8): 1235-9, 1998 Apr 15.
Article in English | MEDLINE | ID: mdl-9719478

ABSTRACT

Ornithine decarboxylase (ODC, EC 4.1.1.17) is the enzyme responsible for the synthesis of polyamines, which are absolutely necessary for cell proliferation. In the present work, we tested the effects of 3 nitric oxide (NO) donors, namely, sodium nitroprusside (SNP), (Z)-1-(N-methyl-N-[6-(N-methylammoniohexyl)amino] diazen-1-ium-1,2-diolate (MAHMA/NO) and 1,1-diethyl-2-hydroxy-2-nitroso-hydrazine sodium (DEA/NO), on ODC activity in human-colon carcinoma cells (HT-29). SNP was the most effective inhibitor of ODC activity with a concentration of 8 micromol/L inducing 50% inhibition of basal activity. The effect of SNP was reversed by haemoglobin (Hb), but not by GSH or L-cysteine (CYS). Very little of the SNP in solution was degraded into nitrite, but the presence of cellular homogenate increased the production of nitrite. MAHMA/NO and DEA/NO were much less effective than SNP as ODC inhibitors, since the concentrations of these agents which induce 50% inhibition of basal activity were 20- to 60-fold higher than that of SNP. The effects of MAHMA/NO and DEA/NO were not reversed by haemoglobin. In solution, these latter 2 agents were totally degraded into nitrites. In conclusion, SNP on the one hand and MAHMA/NO and DEA/NO on the other appeared to release different NOx species with different efficiency on ODC activity.


Subject(s)
Hydrazines/pharmacology , Nitric Oxide/metabolism , Nitroprusside/pharmacology , Ornithine Decarboxylase Inhibitors , Dose-Response Relationship, Drug , HT29 Cells , Humans , Nitrites/metabolism , Nitrogen Oxides
20.
Bull Acad Natl Med ; 180(6): 1455-65; discussion 1465-6, 1996.
Article in French | MEDLINE | ID: mdl-8991618

ABSTRACT

Accurate 3D tumoral volume evaluation is now possible through the combined use and progress of computer graphics technics (3D reconstruction and visualization) and medical imagery (helicoidal TDM scanner). Specific organ and pathology oriented softwares can help answer rapidly to problems posed by oncologic praticians. A new decision support for diagnosis, therapy and follow-up is emerging. First results in liver tumors and hepatic regeneration macroscopic biometrics are presented. Tumoral or organ volumic index will be usable in the follow-up. TNM staging, external conformal radiotherapy for prostatic or brain tumors, drugs cytolytic effects evaluation will take great advantage of these technologies. 3D visualization and matching CT and MRI imagery can help computed assisted surgery.


Subject(s)
Computer Graphics , Diagnosis, Computer-Assisted/methods , Medical Oncology/methods , Radiation Oncology/methods , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/therapy
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