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1.
J Adv Res ; 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36049735

##### RESUMO

INTRODUCTION: Mathematical modelling is a rapidly expanding field that offers new and interesting opportunities for both mathematicians and biologists. Concerning COVID-19, this powerful tool may help humans to prevent the spread of this disease, which has affected the livelihood of all people badly. OBJECTIVES: The main objective of this research is to explore an efficient mathematical model for the investigation of COVID-19 dynamics in a generalized fractional framework. METHODS: The new model in this paper is formulated in the Caputo sense, employs a nonlinear time-varying transmission rate, and consists of ten population classes including susceptible, infected, diagnosed, ailing, recognized, infected real, threatened, diagnosed recovered, healed, and extinct people. The existence of a unique solution is explored for the new model, and the associated dynamical behaviours are discussed in terms of equilibrium points, invariant region, local and global stability, and basic reproduction number. To implement the proposed model numerically, an efficient approximation scheme is employed by the combination of Laplace transform and a successive substitution approach; besides, the corresponding convergence analysis is also investigated. RESULTS: Numerical simulations are reported for various fractional orders, and simulation results are compared with a real case of COVID-19 pandemic in Italy. By using these comparisons between the simulated and measured data, we find the best value of the fractional order with minimum absolute and relative errors. Also, the impact of different parameters on the spread of viral infection is analyzed and studied. CONCLUSION: According to the comparative results with real data, we justify the use of fractional concepts in the mathematical modelling, for the new non-integer formalism simulates the reality more precisely than the classical framework.

2.
Med Oral Patol Oral Cir Bucal ; 27(3): e198-e204, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35420069

##### RESUMO

BACKGROUND: Odontogenic tumors (OTs) are considered important among oral lesions because of their clinicopathological heterogeneity and variable biological behavior. The purpose of this retrospective cross-sectional study was to evaluate the frequency and distribution of different types of odontogenic tumors based on the current 2017 WHO Classification of Head and Neck Tumors over a period of 5 years. This was achieved by reviewing the records of Cairo's educational hospitals and institutions and comparing the results with findings in the literature. MATERIAL AND METHODS: The records of patients diagnosed with odontogenic tumors were obtained from six educational hospitals and a single institute in Cairo which included: Oral and Maxillofacial Pathology Department, Faculty of Dentistry, Cairo University; General Pathology Department, Faculty of Medicine, Cairo University; Oral Pathology Department, Faculty of Dentistry, Ain Shams University; Eldemerdash Hospital, Ain Shams University; El-Sayed Galal Hospital, Al-Azhar University; Ahmed Maher Teaching Hospital and National Cancer Institute. These records were reviewed over a 5-year (2014-2018) period and the odontogenic tumors were investigated for frequency, age, gender and site. The data were recorded, then analyzed using SPSS software. RESULTS: Intraosseous (central) odontogenic tumors constituted 2.56% of all 8974 registered oral and maxillofacial biopsies. A total of 230 cases of OTs were collected and reviewed. Of these, 97.8% were benign and 2.17% were malignant. The mandible was the most commonly affected anatomic location. Ameloblastoma, with a predilection for the posterior mandible, was the most frequent odontogenic tumor (55.65%), followed by cemento-ossifying fibroma (14.78%) and odontoma (9.13%). Females were more commonly affected than males. Most of the patients were in the third and fourth decades of life. There were no peripheral odontogenic tumors diagnosed in this period. CONCLUSIONS: Some similarities and differences between our findings and those of previous studies of various populations were witnessed. OTs may greatly diverge according to the version of the classification used and by the sample size of the study. Retrospective analysis of the relative frequency of OTs in different countries will be helpful in enhancing the understanding of OTs, which is important for both oral maxillofacial surgeons and pathologists.

##### Assuntos
Ameloblastoma , Tumores Odontogênicos , Ameloblastoma/patologia , Estudos Transversais , Egito/epidemiologia , Feminino , Humanos , Masculino , Tumores Odontogênicos/patologia , Compostos Orgânicos , Estudos Retrospectivos
3.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 10): 1591-1594, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33117570

##### RESUMO

The title compound, C17H16N2OS, was synthesized by a condensation reaction between 2-amino benzo-thia-zole and 4-N-propoxybenzaldehyde. The benzo[d]thia-zole ring system is nearly planar (r.m.s. deviation 0.0088âÅ) and makes a dihedral angle of 3.804â(12)° with the phenyl ring. The configuration about the C=N double bond is E. In the crystal structure, pairs of C-Hâ¯N hydrogen bonds and C-Hâ¯π inter-actions link the mol-ecules into inversion dimers with an R 2 2(16) ring motif. These dimers are additionally linked by weak π-π stacking inter-actions between the phenyl rings, leading to a layered arrangement parallel to (010). Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the packing arrangement are from Hâ¯H (47.9%) and Câ¯H/Hâ¯C (25.6%) inter-actions.

4.
Braz. j. biol ; 80(3): 565-573, July-Sept. 2020. tab
Artigo em Inglês | LILACS | ID: biblio-1132399

##### RESUMO

Abstract Due to increased number of herbicide resistant weeds, it is needed to explore the allelopathic potential of plants as an alternative. The research was conducted to investigate allelopathic effects of Carica papaya L. leaf powder and aqueous extract on seeds as well as pre-germinated seeds of Avena fatua L., Helianthus annuus L., Rumex dentatus L., Zea mays L. and Triticum aestivum L. on filter paper and soil in Weed Management Program Laboratory, Department of Plant and Environmental Protection at PARC Institute of Advanced Studies in Agriculture, National Agriculture Research Centre, Islamabad, Pakistan. Germination percentage (%), radicle length (cm) and plumule length (cm) were parameters observed for 'Plant leaf powder bioassay' and 'Aqueous extract method'. Most significant growth inhibition was observed in A. fatua seedlings in filter paper method. A. fatua radicle length was reduced by C. papaya aqueous extract (80%) and leaf powder (89%) bioassays. Plumule length was reduced under the influence of aqueous extract (57-73%) and powdered material (59-77%). The inhibitory effects on other test species were in sequence of H. annuus followed by Z. mays and R. dentatus. The aqueous extract showed non-significant effect on wheat seed germination, radicle and plumule growth. It is suggested that C. papaya aqueous extract can be used as source of weed management in wheat crop.

Resumo Devido ao aumento do número de ervas daninhas resistentes aos herbicidas, é necessário explorar o potencial alelopático das plantas como uma alternativa. A pesquisa foi conduzida com o objetivo de investigar os efeitos alelopáticos do pó foliar de Carica papaya e do extrato aquoso das sementes, bem como das sementes pré-germinadas de Avena fatua, Helianthus annuus, Rumex dentatus, Zea mays e Triticum aestivum em papel de filtro e solo no Laboratório do Programa de Manejo de Ervas Daninhas, Departamento de Plantas e Proteção Ambiental do Instituto PARC de Estudos Avançados em Agricultura, Centro Nacional de Pesquisa Agrícola, Islamabad, Paquistão. A porcentagem de germinação (%), o comprimento radicular e o comprimento da plúmula (cm) foram os parâmetros observados para o 'Bioensaio de Pó de Folha de Planta' e o 'Método de Extração Aquoso'. A maior inibição do crescimento foi observada em mudas de A. fatua no método de papel de filtro. O comprimento radicular de A. fatua foi reduzido com os extratos aquosos de C. papaya (80%) e pó de folhas (89%). O comprimento das plúmulas foi reduzido sob a influência do extrato aquoso (57-73%) e material em pó (59-77%). Os efeitos inibitórios em outras espécies-teste foram na sequência de H. annuus seguido por Z. mays e R. dentatus. O extrato aquoso apresentou efeito não significativo na germinação das sementes de trigo, nos crescimentos radiculares e das plúmulas. Sugere-se que o extrato aquoso de C. papaya pode ser utilizado como fonte de manejo de plantas daninhas na cultura do trigo.

##### Assuntos
Carica , Paquistão , Sementes , Extratos Vegetais , Folhas de Planta , Germinação
5.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 7): 1092-1095, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32695458

##### RESUMO

In the title compound, C27H28N2OS, the naphthalene unit is planar to within 0.015â(2)âÅ and makes a dihedral angle of 14.24â(16)° with the thia-zole ring. The anisole ring is inclined to the thia-zole ring by a dihedral angle of 13.18â(23)°. The torsion angle between the heptyl chain and the anisole ring is 61.1â(4)°. These dihedral and torsion angles render the mol-ecule non-planar. In the crystal, mol-ecules are linked by C-Hâ¯π inter-actions, forming zigzag chains that propagate parallel to the b axis. The roles of the various inter-molecular inter-actions in the crystal packing were clarified by Hirshfeld surface analysis; the most important contributions are from Hâ¯H (51.5%) and Câ¯H/Hâ¯C (31.8%) contacts.

6.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 6): 920-923, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32523764

##### RESUMO

The asymmetric unit of the title compound, C23H20N2OS, contains one slightly bent mol-ecule. The naphthalene ring system and the thia-zole ring are twisted with respect to each other, making a dihedral angle of 13.69â(10)°; the anisole ring is inclined to the plane of the naphthalene ring system, the dihedral angle being 14.22â(12)°. In the crystal structure, mol-ecules are linked by C-Hâ¯π inter-actions, resulting in the formation of sheets parallel to (100). Within the sheets, very weak π-π stacking inter-actions lead to additional stabilization. Hirshfeld surface analysis and fingerprint plots reveal that the cohesion in the crystal structure is dominated by Hâ¯H (42.5%) and Câ¯H/Hâ¯C (37.2%) contacts.

7.
Braz J Biol ; 80(3): 565-573, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31644650

##### RESUMO

Due to increased number of herbicide resistant weeds, it is needed to explore the allelopathic potential of plants as an alternative. The research was conducted to investigate allelopathic effects of Carica papaya L. leaf powder and aqueous extract on seeds as well as pre-germinated seeds of Avena fatua L., Helianthus annuus L., Rumex dentatus L., Zea mays L. and Triticum aestivum L. on filter paper and soil in Weed Management Program Laboratory, Department of Plant and Environmental Protection at PARC Institute of Advanced Studies in Agriculture, National Agriculture Research Centre, Islamabad, Pakistan. Germination percentage (%), radicle length (cm) and plumule length (cm) were parameters observed for 'Plant leaf powder bioassay' and 'Aqueous extract method'. Most significant growth inhibition was observed in A. fatua seedlings in filter paper method. A. fatua radicle length was reduced by C. papaya aqueous extract (80%) and leaf powder (89%) bioassays. Plumule length was reduced under the influence of aqueous extract (57-73%) and powdered material (59-77%). The inhibitory effects on other test species were in sequence of H. annuus followed by Z. mays and R. dentatus. The aqueous extract showed non-significant effect on wheat seed germination, radicle and plumule growth. It is suggested that C. papaya aqueous extract can be used as source of weed management in wheat crop.

##### Assuntos
Carica , Germinação , Paquistão , Extratos Vegetais , Folhas de Planta , Sementes
8.
Eur J Surg Oncol ; 42(6): 813-6, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27012999

##### RESUMO

INTRODUCTION: Anal cancer accounts for a small percentage of colorectal malignancies. Early stage (T1N0M0) cancers of the anal verge have been treated with local surgical excision alone in individuals without human immunodeficiency virus (HIV) infection. The risk of anal cancer is higher in people living with HIV (PLWH). We present results of the outcomes of T1 anal verge cancers treated by local excision only in a series of PLWH. METHODS: Demographic and clinicopathological data was prospectively collected from all HIV positive individuals with anal cancer, treated between 1986 and 2015. The date from anal cancer diagnosis until the date of the last follow up were collected. RESULTS: Fifteen patients had T1N0M0 cancer of the anal verge from a total of 92 patients with HIV-associated anal cancer. The mean age was 49 years (range 36-57). The average age of HIV diagnosis was 35 years (range 19-48) and four patients had a diagnosis of AIDS prior to the diagnosis of anal cancer. All patients were surgically managed with complete local excision of the tumour. There were no complications or need for any adjuvant therapy. No patients have relapsed and at a median follow up of 4 years (range 3-15), the overall survival was 100%. CONCLUSION: Surgical resection for early stage anal verge cancers is an effective strategy in PLWH. Increasing awareness of anal cancer and anoscopy surveillance in PLWH will hopefully continue to identify anal cancers at an early stage that are amenable to minimally invasive surgical management.

##### Assuntos
Canal Anal/cirurgia , Neoplasias do Ânus/patologia , Neoplasias do Ânus/cirurgia , Infecções por HIV/complicações , Adulto , Canal Anal/patologia , Neoplasias do Ânus/complicações , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Estadiamento de Neoplasias , Estudos Prospectivos , Resultado do Tratamento
9.
Dalton Trans ; 44(28): 12796-803, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26091252

##### RESUMO

A giant magnetocaloric effect induced by sodium-deficiency in a La0.8Na0.2-xâ¡xMnO3 (0.00 ≤ x ≤ 0.15) polycrystalline sample is reported in the present research work. The ability to tune the temperature transition close to room temperature is revealed to be possible by changing the sodium-deficiency content as well. All samples were synthesized using solid-solid reaction. X-ray diffraction and magnetization measurements were performed to investigate their crystallographic structure and magnetocaloric properties. A rhombohedral structure with the R3[combining macron]c space group is deduced from pattern diffraction refinement of all samples. A second-order magnetic phase transition from the ferromagnetic to the paramagnetic state at the Curie temperature (Tc) is observed. Such a Tc decreased from 335 to 260 K when the sodium deficiency rate increased. Besides, the magnetic entropy change and the related Relative Cooling Power (RCP) values, sensitive to sodium-deficiency, were estimated. The magnetic entropy change ranges increased from 2.38 J kg(-1) K(-1) to 3.48 J kg(-1) K(-1) under a magnetic field of 2 T, whereas the RCP varied from 210 to 235 J kg(-1) under an applied magnetic field of 5 T, when x increased from 0.00 to 0.15. The comparison of the values reported in the reference Gd material underlines that the proposed oxide material has substantial advantages for magnetic refrigeration.

10.
Arch Pediatr ; 21(3): 296-8, 2014 Mar.
Artigo em Francês | MEDLINE | ID: mdl-24461936

##### RESUMO

Congenital factor XI deficiency, also called hemophilia C, is a rare coagulation disorder that is particularly common in Ashkenazi Jews. Individuals with factor XI deficiency may or may not have a mild bleeding tendency, which is typically provoked by surgery or trauma. We report the case of a 5.5-year-old girl who presented with abdominal pain, vomiting, and hematemesis. Biological tests showed a prolonged activated partial thromboplastin time (aPTT) of 113 s (control=29 s) caused by a constitutional factor Xl deficiency (2.7%). The progression was spontaneously favorable.

##### Assuntos
Deficiência do Fator XI/complicações , Hematemese/etiologia , Pré-Escolar , Feminino , Humanos
11.
Ann Surg Oncol ; 21(2): 527-32, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24242676

##### RESUMO

BACKGROUND: The treatment of anal cancer in human immunodeficiency virus (HIV) patients-as in the general population-is primarily with chemoradiotherapy (CRT), and abdominoperineal resection of residual or recurrent primary disease. The aim of this study was to evaluate the extent of residual primary disease and local recurrence as well as the outcome of salvage surgery after CRT for anal carcinoma in HIV-positive individuals. METHODS: We retrospectively studied HIV-positive anal carcinoma patients treated between February 1989 and November 2012 in a specialist London unit. Extent of residual primary disease, local recurrence after CRT, postoperative complications, and survival after salvage surgery were evaluated. RESULTS: Complete response was experienced in 44 of 53 (83%) of HIV patients treated with CRT for anal carcinoma. One patient (2.3%) developed local recurrence. Nine patients (eight residual primary disease after CRT and one local recurrence) underwent salvage surgery after CRT. There were no perioperative deaths, and perioperative CD4 counts were sustained. Complications occurred in five patients (55%). Median interval to complete perineal healing was 4 months (range 2-11 months), and median hospital stay was 29 days. Survival (median 16 months) was 25% at 2 years from salvage surgery. CONCLUSIONS: Results in HIV-positive patients receiving highly active antiretroviral therapy (HAART) suggest that loss of HIV sensitivity to HAART can be avoided, but that there is increased postoperative morbidity that may be related to HIV disease. Survival was comparable to that for salvage therapy after optimal CRT in non-HIV anal carcinoma patients.

##### Assuntos
12.
Arch Pediatr ; 20(7): 783-6, 2013 Jul.
Artigo em Francês | MEDLINE | ID: mdl-23727372

##### RESUMO

Canavan disease, or N-acetyl aspartic aciduria, is an autosomal recessive leukodystrophy characterized by spongy degeneration of the brain. The disease results from the accumulation of N-acetyl aspartic acid in the brain, due to aspartoacylase deficiency. We report the case of a 6-month-old girl who presented with megalencephaly, peripheral hypertonia, and a developmental delay noticeable after 4 months of age. Magnetic resonance imaging of the brain with spectroscopy was suggestive of Canavan disease, which was confirmed by chromatography of urinary organic acids.

##### Assuntos
Doença de Canavan/diagnóstico , Distonia/etiologia , Megalencefalia/etiologia , Ácido Aspártico/urina , Encéfalo/patologia , Deficiências do Desenvolvimento/etiologia , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética
13.
Ann Oncol ; 23(1): 141-147, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21444358

##### RESUMO

BACKGROUND: Despite the advent of highly active antiretroviral therapy, anal cancer remains a significant health problem in human immunodeficiency virus (HIV) patients. We present the clinical features and treatment outcomes of anal cancer in 60 HIV-positive patients over a 20-year period. PATIENTS AND METHODS: A prospective database of all HIV-positive individuals managed in a specialist unit since 1986 includes 11 112 patients (71 687 person-years of follow-up). Sixty patients with anal cancer were identified. Their clinicopathological and treatment details were analysed. RESULTS: At anal cancer diagnosis, the mean age was 44 years (range: 28-75 years) and the median CD4 cell count was 305 mm(-3) (range: 16-1252 mm(-3)). Fifty (83%) had chemoradiotherapy (CRT). Forty-six (92%) responded, of whom 10 (22%) subsequently relapsed with locoregional (70%), metastatic disease (10%) or both (20%). The overall 5-year survival is 65% (95% confidence interval 51% to 78%). The median CD4 count fell from 289 mm(-3) before CRT to 132 mm(-3) after 3 months and to 189 mm(-3) after 1 year (P<0.05). Six patients in remission of anal cancer died of acquired immunodeficiency syndrome defining illnesses. CONCLUSIONS: The management of anal cancer with CRT achieves similar outcomes as the general population. CRT is associated with significant prolonged CD4 suppression that may contribute to late deaths of patients in remission.

##### Assuntos
14.
Ann Nucl Med ; 25(3): 207-11, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21107761

##### RESUMO

AIMS AND OBJECTIVE: A normal gated myocardial perfusion imaging (GMPI) has been found to have high diagnostic and negative predictive value (NPV) in western population. The goal of the present study was to evaluate the overall and gender-based NPV of a normal GMPI in local population. PATIENTS AND METHODS: This is a prospective study conducted at Nuclear Cardiology Department of Karachi Institute of Heart Diseases (KIHD), Karachi from December 2008 till May 2009. All patients (with intermediate risk) with a normal GMPI with adequate dynamic or dipyridamole stress were included and followed up for 18 months (mean 15 ± 3 months) for fatal or non-fatal infarctions. RESULTS: The mean ejection fraction (EF) of studied population was 69 ± 8% while mean end diastolic (EDV) and end systolic volume (ESV) were 71 ± 19 and 22 ± 11 ml, respectively. In studied female cohort, the mean EF (%), EDV (ml) and ESV (ml) were 71 ± 08, 64 ± 15 and 19 ± 09, respectively. In studied male cohort, the mean EF (%), EDV (ml) and ESV (ml) were 66 ± 06, 82 ± 18 and 27 ± 11, respectively. At 18 months follow-up, one fatal (male patient) and one non-fatal MI (male patient) were reported. The overall NPV was 99.4% over 18 months follow-up with an event rate of 0.6% (95% CI 0.03-1.16%) and annualized event rate of 0.3%. The NPV and annualized event in subgroup analyses, was similar for female and male (P = 0.213). CONCLUSION: We conclude that a normal GMPI with adequate stress in our population has high NPVs for major cardiac events as in western population. In addition, the prognostic utility of GMPI is similar for both men and women.

##### Assuntos
Tomografia Computadorizada por Emissão de Fóton Único de Sincronização Cardíaca/métodos , Imagem de Perfusão do Miocárdio/métodos , Estudos de Coortes , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores Sexuais
15.
Surgeon ; 5(1): 58-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17313131

##### RESUMO

We report a patient in whom the diagnoses of the syndrome of inappropriate anti-diuretic hormone secretion (SIADH) and gastric carcinoma were made concurrently. After a gastrectomy, there was resolution of the electrolyte disturbances. This represents the third reported case of this association in the English language literature.

##### Assuntos
16.
Pak J Biol Sci ; 10(19): 3405-9, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19090159

##### RESUMO

The behaviors of fission products is studied in this study with the principal objective of making a comparison between Deep Atomic Binding (DAB) Approach and other models used to interpret the health effects of fission products on human body. Large numbers of fatalities, malignancies, thyroid cancer, born (genic) defects were predicted as health effects of fission products on human body. Nevertheless, the facts after real releases of fission products were not consistent with what was predicted. DAB Approach interprets these facts and reduces radiophobia as well as radiation protection expenses.

##### Assuntos
17.
Med Princ Pract ; 15(1): 9-23, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16340222

##### RESUMO

OBJECTIVE: To examine varicose veins (VVs) from inside out in order to help surgeons and general practitioners better understand the pathogenesis of the disease and improve their management. MATERIAL AND METHODS: A comprehensive examination of the wall of VVs was performed using transmission electron microscopy. The ultrastructural morphology of the collagen, elastin and smooth muscle content of the wall was analyzed in a sample of 10 patients (4 male and 6 female) and 10 matched controls aged between 37 and 50 years. RESULTS: Analysis of the tunica media revealed that the smooth muscle cells were significantly separated from each other by a marked increase in amorphous and fibrous tissue in which many of the collagen and elastin fibers lost their normal structural arrangement. The cells contained a large number of membrane-bound intracellular vesicles and cytoplasmic vacuoles. The collagen fibers were smaller and thinner than what is commonly seen in normal veins, and they were widely separated from each other. A light electron-lucent center was observed in the middle of the fibers. Similar changes were also seen in the intima and were associated with irregular plaque-like intimal thickening. CONCLUSION: Our study revealed a significant separation among smooth muscle cells in the wall of VVs, and the presence of an abnormal amorphous extracellular matrix and intracytoplasmic vacuoles could reflect 'unusual' possible secretory and phagocytic roles of smooth muscle cells. This could provide an important explanation for the abnormal contractile function of these cells in VVs.

##### Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Médicos , Varizes/patologia , Adulto , Estudos de Casos e Controles , Colágeno/ultraestrutura , Elastina/ultraestrutura , Feminino , Humanos , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Músculo Liso Vascular/patologia , Músculo Liso Vascular/ultraestrutura , Arábia Saudita
18.
Int Angiol ; 22(2): 188-93, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12865886

##### RESUMO

AIM: Vein wall distensibility is controlled by collagen, elastin and smooth muscle cells. However, contradicting evidence exists on the connective tissue concentration and smooth muscle pathology in varicose veins. METHODS: To study the pathological changes in the wall of varicose veins at different levels, we collected a total of 49 vein specimens from 19 patients at Asir Central Hospital, Abha, Saudi Arabia, during the period from March to October 1997. Three young trauma patients underwent repair of their arterial injuries using the thigh long saphenous vein (LSV) and 16 varicose vein patients underwent stripping of their LSV and avulsion of their distal calf varicosities. In the trauma patients, specimens were collected from the proximal thigh LSV while in the varicose vein patients, specimens were collected from both the groin and mid-thigh LSV and the distal calf varicosities. Specimens were stained with Hematoxylin & Eosin, Masson's Trichrome and von Gieson (VG) stains for examination under the light microscope. RESULTS: Compared with the normal LSV, all varicose vein sections showed marked intimal hypertrophy due fibrous tissue infiltration, localized thinning of the muscle layer and loss of both the intimal and medial smooth muscle cells (SMCs). Elastic fibers were deficient and scattered with loss of the normal elastin/collagen lattice network and decrease in both the muscle/collagen and elastin/collagen ratios. CONCLUSION: In conclusion, we propose that dilatation and distensibility of the vein wall under normal and increased venous pressure is due to deficiency in smooth muscle cells and elastic fibers and disproportionate increase in fibrous tissue.

##### Assuntos
Varizes/patologia , Adolescente , Adulto , Endotélio Vascular/patologia , Feminino , Veia Femoral/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/irrigação sanguínea , Músculo Liso Vascular/citologia , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Estudos Prospectivos , Veia Safena/patologia , Arábia Saudita , Índice de Gravidade de Doença , Túnica Íntima/citologia , Túnica Íntima/patologia
19.
Gut ; 51(2): 248-52, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12117889

##### RESUMO

BACKGROUND AND AIM: Cirrhosis with liver failure due to hepatitis C virus (HCV) infection is the most common indication for liver transplantation (LT). Reinfection of the transplanted liver by HCV is inevitable, and aggressive hepatitis with accelerated progression to graft cirrhosis may be observed. Of concern, recent reports suggest that the outcome of LT for HCV may have deteriorated in recent years. Determinants of rate of progression to cirrhosis in the immunocompetent non-transplant patient are well defined, and the most powerful determinant is patient age at the time of infection. Following LT for HCV, recipient age does not affect outcome of HCV reinfection. However, the impact of donor age on graft fibrosis progression rate following LT has not been examined. METHODS: We have examined post-transplant biopsies to assess histological activity, including fibrosis stage (scored 0-6 units, 6 representing established cirrhosis), and to calculate fibrosis progression rates in 101 post-transplant specimens from 56 HCV infected LT patients. Univariate and multivariate analyses examined the impact of parameters including recipient and donor age and sex on fibrosis progression rate, and on predicted time to cirrhosis. RESULTS: For the cohort, median fibrosis progression rate was 0.78 units/year, and median interval from transplantation to development of cirrhosis was 7.7 years. In multivariate analysis, donor age (not recipient age) was a powerful determinant (p=0.02) of fibrosis progression rate. When the liver donor was younger than 40 years, median progression rate was 0.6 units/year and interval to cirrhosis was 10 years. When the donor was aged 50 years or more, median progression rate was 2.7 units/year and interval to cirrhosis only 2.2 years. During the observation period there has been a significant increase in donor age (p=0.01) but date of transplantation per se is not a determinant of progression rate when included in multivariate analyses. CONCLUSIONS: Donor age has a major influence on graft outcome following transplantation for HCV. The changing organ donor profile will affect the long term results of LT for HCV. These observations have important implications for donor liver allocation.

##### Assuntos
Envelhecimento , Hepatite C/cirurgia , Cirrose Hepática/patologia , Transplante de Fígado , Doadores de Tecidos , Adulto , Idoso , Progressão da Doença , Feminino , Hepatite C/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva , Transplante Homólogo
20.
Afr J Med Med Sci ; 31(3): 219-22, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12751560

##### RESUMO

The aim of this prospective, controlled study is to compare the oxygen tension of blood from varicose veins with that from both the antecubital vein of the same patients and the normal long saphenous vein of normal controls at high altitude in Abha (8,000 feet above sea level), Saudi Arabia. Forty-two subjects (21 normal controls and 21 with uncomplicated primary varicose veins) had blood samples taken from 41 normal long saphenous veins and 35 varicose veins near the ankle, respectively (a total of 76 lower limbs). Samples were also taken simultaneously from the right antecubital vein in all the subjects. There was no difference in either oxygen tension (pO2) or saturation (sO2) between blood from varicose veins and blood from normal long saphenous veins. However, in patients with varicose veins, both pO2 and sO2 of varicose veins blood were significantly higher than those of arm venous blood (P = 0.009 and P = 0.018, respectively). In normal subjects, blood from normal long saphenous veins had also significantly higher sO2 (P = 0.001) than that from arm veins, but pO2 was not higher. In conclusion, the theory of arteriovenous communication is poorly founded. There must be other more important explanations for the pathogenesis of varicose veins.

##### Assuntos
Oxigênio/sangue , Varizes/sangue , Adulto , Altitude , Braço/irrigação sanguínea , Fístula Arteriovenosa/complicações , Gasometria , Estudos de Casos e Controles , Feminino , Humanos , Perna (Membro)/irrigação sanguínea , Masculino , Estudos Prospectivos , Veia Safena , Arábia Saudita , Distribuição Tecidual , Ultrassonografia Doppler , Varizes/diagnóstico por imagem , Varizes/etiologia , Veias
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