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1.
Clin. transl. oncol. (Print) ; 24(5): 757-769, mayo 2022.
Artigo em Inglês | IBECS | ID: ibc-203779

RESUMO

Colorectal cancer (CRC) is one of the leading causes of mortality among cancers. Many aspects of this cancer are under investigation to find established markers of diagnosis, prognosis, and also potential drug targets. In this review article, we are going to discuss the possible solution to all these aims by investigating the literature about cancer-associated fibroblasts (CAFs) involved in CRC. Moreover, we are going to review their interaction with the tumor microenvironment (TME) and vitamin D and their role in tumorigenesis and metastasis. Moreover, we are going to expand more on some markers produced by them or related to them including FAP, a-SMA, CXCL12, TGF- β, POSTN, and β1-Integrin. Some signaling pathways related to CAFs are as follows: FAK, AKT, activin A, and YAP/TAZ. Some genes related to the CAFs which are found to be possible therapeutic targets include COL3A1, JAM3, AEBP1 and, CAF-derived TGFB3, WNT2, and WNT54.


Assuntos
Humanos , Fibroblastos Associados a Câncer/metabolismo , Carboxipeptidases/metabolismo , Carcinogênese/patologia , Neoplasias Colorretais/patologia , Microambiente Tumoral , Fibroblastos/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Crescimento Endotelial/metabolismo
2.
Clin Transl Oncol ; 24(5): 757-769, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34839457

RESUMO

Colorectal cancer (CRC) is one of the leading causes of mortality among cancers. Many aspects of this cancer are under investigation to find established markers of diagnosis, prognosis, and also potential drug targets. In this review article, we are going to discuss the possible solution to all these aims by investigating the literature about cancer-associated fibroblasts (CAFs) involved in CRC. Moreover, we are going to review their interaction with the tumor microenvironment (TME) and vitamin D and their role in tumorigenesis and metastasis. Moreover, we are going to expand more on some markers produced by them or related to them including FAP, a-SMA, CXCL12, TGF- ß, POSTN, and ß1-Integrin. Some signaling pathways related to CAFs are as follows: FAK, AKT, activin A, and YAP/TAZ. Some genes related to the CAFs which are found to be possible therapeutic targets include COL3A1, JAM3, AEBP1 and, CAF-derived TGFB3, WNT2, and WNT54.


Assuntos
Fibroblastos Associados a Câncer , Neoplasias Colorretais , Fibroblastos Associados a Câncer/metabolismo , Carboxipeptidases/metabolismo , Carcinogênese/patologia , Neoplasias Colorretais/patologia , Fibroblastos/metabolismo , Humanos , Prognóstico , Proteínas Repressoras/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Microambiente Tumoral
3.
Andrologia ; 48(9): 890-894, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27739146

RESUMO

Microdeletions of the azoospermia factor (AZF) regions in the Y chromosome are a well-known genetic cause of male infertility, resulting in impairment of spermatogenesis. However, the partial deletions of AZFc region related to spermatogenetic impairment are controversial. We investigated partial deletion of AZFc region and DAZ copy number in a population of Iranian infertile men and normozoospermic controls. In total, 154 infertile men (113 patients with azoospermia, 41 with oligozoospermia) and 111 normozoospermic controls were analysed using PCR. Gene dosage analysis of the DAZ genes was performed by fragment analysis. Our results showed that the frequencies of gr/gr deletion in the azoospermic, severe oligozoospermic and normozoospermic men were 4.4% (5/113), 7.3% (3/41) and 1.8% (2/111) respectively. In the azoospermic patients, the frequency of b2/b3 was 1.8% (2/113). Partial AZFc deletions were not significantly different between the infertile and normozoospermic men. The frequencies of gr/gr deletions and b2/b3 were not significantly different between the azoospermic/severe oligozoospermic men and normozoospermic controls. Our data suggested that gr/gr deletion was not associated with azoospermia/oligozoospermia in an Iranian population.


Assuntos
Azoospermia/genética , Doenças Genéticas Ligadas ao Cromossomo Y/genética , Oligospermia/genética , Proteínas de Ligação a RNA/genética , Adulto , Estudos de Casos e Controles , Cromossomos Humanos Y/genética , Proteína 1 Suprimida em Azoospermia , Deleção de Genes , Dosagem de Genes , Humanos , Infertilidade Masculina/genética , Masculino , Pessoa de Meia-Idade , Espermatogênese/genética
4.
Haemophilia ; 20(2): 185-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24118441

RESUMO

Joint destruction in early adulthood brings the patients to the orthopaedic clinics. If a haemophilic patient becomes disabled, it shows a number of factors such as timely diagnosis, availability of appropriate treatment depending on the country, access and affordability to treatments and equally importantly the responsibility of the patient in managing self care by remaining compliant by prescribed treatment regimen. We assessed the functional level by functional independence score in haemophilia (FISH). Overall, 104 patients with haemophilia A and 29 with haemophilia B were evaluated. We assessed the function of the patients by FISH. We divided the sum scores into weak (FISH score 8-16), moderate (17-24), and good (25-32). For evaluating the level of functional deficit in a 2 × 2 table, we categorized the weak and moderate levels into Disordered Group and the good level into Not-Disordered Group. The average age was 26.9 ± 14.24. Each 1 year increase in age can increase 1.07 fold the possibility of being placed in Disordered Function Group. Severe haemophilia can increase 7.34 fold, presence of inhibitor can increase 9.75 fold and home self-care increases 3.89 fold the possibility of being placed in Disordered Function Group. To decrease the burden of the cost on patient, family and the government, education plays the most important role. We suggest that we send a trained team of physician and nurses to the deprived villages and cities instead of waiting for the patient to refer to our Care Center.


Assuntos
Hemartrose/etiologia , Hemartrose/reabilitação , Hemofilia A/complicações , Hemofilia A/epidemiologia , Hemofilia B/complicações , Hemofilia B/epidemiologia , Atividades Cotidianas , Adolescente , Adulto , Criança , Estudos Transversais , Gerenciamento Clínico , Hemofilia A/terapia , Hemofilia B/terapia , Humanos , Fatores de Risco , Autocuidado , Inquéritos e Questionários , Adulto Jovem
5.
Opt Express ; 18(14): 14604-15, 2010 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-20639946

RESUMO

In this paper we present a novel long wave length infrared quantum dot photodetector. A cubic shaped 6nm GaN quantum dot (QD) within a large 18 nm Al(0.2)Ga(0.8)N QD (capping layer) embedded in Al(0.8)Ga(0.2)N has been considered as the unit cell of the active layer of the device. Single band effective mass approximation has been applied in order to calculate the QD electronic structure. The temperature dependent behavior of the responsivity and dark current were presented and discussed for different applied electric fields. The capping layer has been proposed to improve upon the dark current of the detector. The proposed device has demonstrated exceptionally low dark current, therefore low noise, and high detectivity. Excellent specific detectivity (D*) up to approximately 3 x 10(8)CmHz(1/ 2)/W is achieved at room temperature.

6.
Genet Couns ; 18(4): 417-21, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18286823

RESUMO

We report a male neonate with a 45 X karyotype; the long arm of a chromosome 15 was translocated onto the proximal long arm of the Y chromosome. Breakpoints were identified by in situ fluorescence hybridization (FISH) on the proximal 15q13 and Yq11.2. The derivative chromosome has no primary centromere. Clinical features were compatible with Prader-Willi syndrome. This is the first report case ofmonosomy 15q and Yq deletion with Prader-Willi syndrome.


Assuntos
Cromossomos Humanos Par 15/genética , Cromossomos Humanos X/genética , Cromossomos Humanos Y/genética , Síndrome de Prader-Willi/genética , Translocação Genética , Criptorquidismo , Deleção de Genes , Humanos , Recém-Nascido , Doenças do Recém-Nascido , Recém-Nascido Prematuro , Cariotipagem , Masculino , Fenótipo
7.
J Clin Periodontol ; 27(9): 698-704, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10983604

RESUMO

BACKGROUND: Transforming growth factor-beta (TGF-beta) represents a family of growth-modulating proteins with fundamental roles in connective tissue and bone development. The objective of this study was to evaluate the potential for regeneration of alveolar bone and cementum following surgical implantation of recombinant human TGF-beta 1 (rhTGF-beta 1). METHOD: Bilateral, critical size, supra-alveolar periodontal defects in 5 beagle dogs were surgically implanted with rhTGF-beta 1 in a calcium carbonate carrier (CaCO3) or with carrier alone. The animals were euthanized at 4 weeks postsurgery and block-biopsies of the defects were processed for histologic and histometric analysis. RESULTS: Surgical implantation of rhTGF-beta 1 resulted in minimal, if any, stimulation of alveolar bone or cementum regeneration. Linear bone and cementum regeneration in rhTGF-beta 1-treated defects was 1.2+/-0.6 and 0.01+0.01 mm, respectively. Corresponding values for the controls were 1.0+/-0.6 and 0.01+/-0.03 mm. CONCLUSIONS: The results suggest that, under the conditions (dose, carrier, defect type) evaluated here, treatment of periodontal defects in beagle dogs with rhTGF-beta 1 may be of limited clinical benefit.


Assuntos
Processo Alveolar/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Cemento Dentário/efeitos dos fármacos , Doenças Periodontais/tratamento farmacológico , Fator de Crescimento Transformador beta/administração & dosagem , Processo Alveolar/patologia , Processo Alveolar/fisiopatologia , Animais , Regeneração Óssea/fisiologia , Cemento Dentário/patologia , Cemento Dentário/fisiopatologia , Modelos Animais de Doenças , Cães , Avaliação Pré-Clínica de Medicamentos , Implantes de Medicamento , Humanos , Masculino , Doenças Periodontais/patologia , Doenças Periodontais/fisiopatologia , Proteínas Recombinantes/administração & dosagem
9.
J Clin Periodontol ; 25(6): 475-81, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9667481

RESUMO

This study evaluated alveolar bone and cementum regeneration following surgical implantation of recombinant human transforming growth factor-beta1 (rhTGF-beta1) in conjunction with guided tissue regeneration (GTR). Supraalveolar, critical size, periodontal defects were surgically created around the 3rd and 4th mandibular premolar teeth in right and left jaw quadrants in 5 beagle dogs. Alternate jaw quadrants in consecutive animals received rhTGF-beta1, in a CaCO3/hydroxyethyl starch carrier with GTR, or carrier with GTR alone (control). 20 microg of rhTGF-beta1 in buffer solution was incorporated into approximately 0.8 ml of carrier for each defect scheduled to receive rhTGF-beta1. Animals were sacrificed at week 4 postsurgery and tissue blocks were harvested and processed for histometric analysis. Clinical healing was generally uneventful. Minor membrane exposures were observed. Defects with membrane exposure displayed an inflammatory infiltrate underneath the membrane. Bone regeneration of trabecular nature, apparent in all animals, was generally limited to the very apical aspect of the defects. Cementum regeneration was limited without obvious differences between experimental conditions. Comparing rhTGF-beta1, to control defects, statistically significant differences were found for area (1.8+/-0.4 and 1.3+/-0.6 mm2, respectively; p<0.05) and density (0.3+/-0.1 and 0.2+/-0.03, respectively; p<0.05) of alveolar bone regeneration. Observed differences are small and represent a clinically insignificant potential for enhanced regeneration in this preclinical model. Within the limitations of study, it may be concluded that rhTGF-beta1 has a restricted potential to enhance alveolar bone regeneration in conjunction with GTR.


Assuntos
Regeneração Tecidual Guiada Periodontal/métodos , Fator de Crescimento Transformador beta/uso terapêutico , Perda do Osso Alveolar/cirurgia , Processo Alveolar/patologia , Animais , Dente Pré-Molar , Regeneração Óssea , Carbonato de Cálcio , Cemento Dentário/patologia , Cães , Portadores de Fármacos , Defeitos da Furca/cirurgia , Humanos , Derivados de Hidroxietil Amido , Membranas Artificiais , Doenças Periodontais/cirurgia , Politetrafluoretileno , Proteínas Recombinantes , Regeneração , Fator de Crescimento Transformador beta/administração & dosagem
10.
J Urol ; 158(2): 519-21, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9224337

RESUMO

PURPOSE: We attempted to determine whether an introducer tip catheter reduces urinary tract infection in spinal cord injured patients on intermittent catheterization. MATERIALS AND METHODS: The introducer tip catheter bypasses the colonized 1.5 cm. of the distal urethra. Enrolled patients were prospectively entered into the study in alternate groups depending on whether they reflex voided: group 1--on intermittent catheterization with the introducer tip catheter but not voiding spontaneously or wearing an external urinary catheter, group 2--same as group 1 but using a nonintroducer tip catheter; group 3--on intermittent catheterization with the introducer tip catheter, voiding by reflex and wearing an external urinary catheter, and group 4--same as group 3 but using a nonintroducer tip catheter. RESULTS: Statistical significance was shown when comparing patients using versus not using the introducer tip catheter regardless of whether an external urinary catheter was worn (p = 0.0121). A greater difference was noted between patients using and not using the introducer tip catheter in the intermittent catheterization only group (p = 0.0093). CONCLUSIONS: The introducer tip catheter decreased urinary tract infections in hospitalized men with spinal cord injury on intermittent catheterization.


Assuntos
Traumatismos da Medula Espinal/complicações , Cateterismo Urinário/efeitos adversos , Cateterismo Urinário/instrumentação , Infecções Urinárias/etiologia , Infecções Urinárias/prevenção & controle , Adolescente , Adulto , Desenho de Equipamento , Humanos , Incidência , Estudos Prospectivos , Bexiga Urinária/microbiologia , Infecções Urinárias/epidemiologia
11.
J Spinal Cord Med ; 19(3): 186-9, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8819027

RESUMO

This study is a prospective multicenter cooperative survey of the evaluation and treatment of erectile dysfunction in men with spinal cord injury (SCI). Uniform database questionnaires were completed prospectively by patients seeking therapy for erectile dysfunction. Eighty-five SCI men aged 17-68 years (mean age = 26 +/- 17) were enrolled. Mean duration of traumatic SCI was 3 +/- 3.2 years (Range = 0.3-18 years). The level of injury was cervical in 20 patients, thoracic in 31, lumbar in 29 and sacral in five. Patients were fully evaluated and then counseled as to their therapeutic options. Twenty-eight chose to use a vacuum erection device (VED), 26 preferred pharmacological penile injection and five used both intracorporeal therapy and VED. The remainder were managed with marriage and sexual counseling in 10 patients, three underwent penile prosthesis placement and two used topical pharmacotherapy. Four patients used other forms of treatment and in nine no therapy was recommended. Of the patients that used pharmacologic injection only, 74 percent used papaverine as a single agent, 20 percent used papaverine with phentolamine, five percent used prostaglandin E (PGE1) alone and one percent used a mixture. Patients using injection therapy report sexual intercourse a mean of 3 +/- 3.4 times per month as compared with 5 +/- 3.2 times per month in those using VED. Five intracorporeal injection patients developed priapism while two patients using the VED developed subcutaneous bleeding and one developed penile ischemia. We conclude that although a spectrum of erectile dysfunction treatment is present among SCI centers, VED and pharmacological penile injection are by far the two most popular methods of treatment and papaverine is the most common drug. The incidence of complications is small in the model centers.


Assuntos
Impotência Vasculogênica/reabilitação , Traumatismos da Medula Espinal/reabilitação , Adolescente , Adulto , Idoso , Alprostadil/administração & dosagem , Humanos , Impotência Vasculogênica/epidemiologia , Masculino , Pessoa de Meia-Idade , Papaverina/administração & dosagem , Satisfação do Paciente , Prótese de Pênis , Fentolamina/administração & dosagem , Estudos Prospectivos , Centros de Reabilitação , Traumatismos da Medula Espinal/epidemiologia , Estados Unidos , Vácuo
12.
J Spinal Cord Med ; 19(3): 197-200, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8819030

RESUMO

Lower urinary tract reconstruction has been performed on the spinal injured population at our institution since 1988. Careful pre-operative evaluation including a detailed history, physical examination and radiographic and/or urodynamic studies are usually obtained to determine which type of procedure would be most beneficial for each individual patient. Typically, patients receive either a cutaneous (i.e., Kock or Indiana) diversion or undergo a form of bladder augmentation (usually ileocystoplasty). Pre-operative findings and the patient's history are carefully considered prior to choosing the appropriate procedure. Occasionally, a particular finding influences the decision. We describe a patient who received a hemi-Kock ileocystoplasty with a continent abdominal stoma who, in retrospect, would have benefitted from a supravesical diversion.


Assuntos
Traumatismos da Medula Espinal/cirurgia , Bexiga Urinaria Neurogênica/cirurgia , Derivação Urinária/métodos , Coletores de Urina/métodos , Adulto , Gangrena de Fournier/cirurgia , Humanos , Masculino , Complicações Pós-Operatórias/cirurgia , Reoperação , Estudos Retrospectivos , Técnicas de Sutura , Resultado do Tratamento , Urodinâmica/fisiologia
13.
Urology ; 46(6): 801-3, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7502419

RESUMO

OBJECTIVES: Since 1986, we have offered the option of lower urinary tract reconstruction with the Kock ileal-urethral reservoir in selected male patients requiring diversion. This study provides insight into the functional characteristics of the Kock ileal-urethral reservoir and its effect on continence. METHODS: Twenty-four of the initial 225 male patients undergoing this procedure at our institution were evaluated by fluorourodynamics within 2 years of neobladder construction. Information regarding continence was also obtained by means of a patient interview and questionnaire. RESULTS: The average resting neobladder pressure was 8.5 cm H2O (range, 0 to 18). Reservoir capacity averaged 741 cc (range, 225 to 1400). Afferent nipple failure with bilateral grade II vesicoureteral reflux was noted in 1 patient (4%). Unsatisfactory daytime continence was seen in 2 patients (8%). Unsatisfactory nighttime continence was seen in 6 patients (25%). Patient satisfaction was high with an average rating of 8.6 on a scale of 1 to 10. CONCLUSIONS: Fluorourdynamic data demonstrate a low-pressure, high-capacity reservoir with a low incidence of reflux. The rate of continence is acceptable and patient satisfaction is excellent. The Kock ilealurethral reservoir is an excellent alternative to standard diversion for the male patient undergoing cystectomy.


Assuntos
Coletores de Urina , Urodinâmica , Adulto , Idoso , Idoso de 80 Anos ou mais , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Resultado do Tratamento , Coletores de Urina/efeitos adversos , Micção , Refluxo Vesicoureteral/etiologia , Gravação em Vídeo
14.
Braz J Med Biol Res ; 28(7): 773-9, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8580869

RESUMO

The development of malignant tissue in vivo is partially favored by the immunosuppression that occurs in cancer patients. However, the signals between tumor and immune tissues remain to be identified. We present evidence that prostaglandins may act as one of these signals by a direct action on cells of the immune system, or by inhibition of insulin secretion which in turn suppresses immune function, or both.


Assuntos
Terapia de Imunossupressão , Insulina/fisiologia , Neoplasias/imunologia , Prostaglandinas/fisiologia , Animais , Carcinoma 256 de Walker/patologia , Carcinoma de Células Acinares/patologia , Humanos , Insulina/sangue , Insulina/metabolismo , Secreção de Insulina , Neoplasias/patologia , Ratos
15.
Braz. j. med. biol. res ; 28(7): 773-9, July 1995. ilus, tab
Artigo em Inglês | LILACS | ID: lil-155261

RESUMO

The development of malignant tissue in vivo is partially favored by the immunosuppression that occurs in cancer patients. However, the signals between tumor and immune tissues remain to be identified. We present evidence that prostaglandins may act as one of these signals by a direct action on cells of the immune system, or by inhibition of insulin secretion which in turn suppresses immune function, or both


Assuntos
Humanos , Animais , Ratos , Terapia de Imunossupressão , Insulina/sangue , Neoplasias/patologia , Prostaglandinas/fisiologia , Carcinoma 256 de Walker/patologia , Carcinoma de Células Acinares/patologia , Insulina/metabolismo , Neoplasias/imunologia
16.
J Spinal Cord Med ; 18(2): 88-94, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7640978

RESUMO

This effort represents a subset analysis of the long-term Multicenter North American Trial of the UroLume sphincter stent prosthesis to determine the effect of the sphincter stent prosthesis in SCI men afflicted with detrusor-external sphincter dyssynergia (DESD) and chronically managed with an indwelling urinary catheter. Forty-one of 153 male patients in this study were evaluated urodynamically before and after placement of the sphincter stent prosthesis. Of the 41 patients, 34 (81 percent) suffered cervical-level injury while 10 patients (25 percent) had been treated previously with external sphincterotomy. Forty patients (98 percent) were troubled with recurrent urinary tract infections (UTI), with a mean of 4.6 +/- 3 episodes of UTI per year. Seven patients (17 percent) demonstrated hydronephrosis prior to stent placement. Follow-up ranged from six to 44 months. Voiding pressures decreased from a mean of 77 +/- 23 cmH2O preoperatively to 35 +/- 18 cmH2O at 12 months (n = 34) and 33 +/- 20 cmH2O at 24 months (n = 22) after stent insertion (p = 0.001). Post-void residual urinary volume decreased from 202 +/- 187 ml preinsertion to 64 +/- 69 ml at 24 months (p = 0.001) postinsertion. Maximum cystometric capacity remained constant at 201 +/- 144 ml preinsertion to 203 +/- 79 ml at 24 months (p = 0.75) postinsertion. No significant changes in any of the urodynamic parameters occurred after 24 months of follow-up between patients with (n = 10) and without (n = 31) previous external sphincterotomy. Neither hemorrhage requiring blood transfusion, obstructive hyperplastic epithelial overgrowth, stent encrustation or stone formation, nor soft tissue erosion occurred in any patient.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Traumatismos da Medula Espinal/complicações , Bexiga Urinaria Neurogênica/etiologia , Bexiga Urinaria Neurogênica/terapia , Incontinência Urinária/etiologia , Incontinência Urinária/terapia , Esfíncter Urinário Artificial , Adulto , Idoso , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Esfíncter Urinário Artificial/efeitos adversos , Urodinâmica
17.
J Pharmacol Toxicol Methods ; 28(4): 181-4, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1296822

RESUMO

Incubation of isolated pancreatic rat islets in a medium consisting of fresh rat or human sera and the measurement of insulin secretion after 60 min in the presence of 6.0-7.0 and 16.7 mM of glucose, were carried out. Perifusion experiments with isolated rat islets preincubated in the presence of rat or human sera and 0.2 mCi/mL of 45Ca2+ were also performed, and 45Ca2+ outflow rate and insulin secretion were analyzed. In both experiments, the usual islet responsiveness to glucose stimulation was preserved when compared with experiments in which Krebs-Henseleit (K-H) buffer was used as the medium. The results obtained demonstrate that both rat and human sera can be used as media for islets perifusion and incubation experiments, thus allowing for the effect(s) of circulating substances on insulin release to be examined.


Assuntos
Sangue , Meios de Cultura , Ilhotas Pancreáticas/fisiologia , Preservação de Tecido/métodos , Adulto , Animais , Análise Química do Sangue , Glicemia/análise , Cálcio/metabolismo , Radioisótopos de Cálcio , Humanos , Técnicas In Vitro , Insulina/metabolismo , Secreção de Insulina , Masculino , Ratos
18.
Talanta ; 39(3): 281-4, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18965375

RESUMO

Determination of vanadium at low concentrations is easily performed with pyrogallol as a ligand which forms a bluish-violet complex with vanadium(III), (IV) or (V). The colour of the bluish-violet complex (lambda(max) = 580 nm) contrasts well with the colour of both pyrogallol and vanadium. The complexes are stable for several hours. Beer's law is obeyed over the range 0-14 mug/ml vanadium at pH 6. The apparent molar absorptivity at 580 nm is (7.75 +/- 0.25) x 10(3)1.mole(-1).cm(-1). The effects of diverse ions on the determination of vanadium have been fully studied. Only Mo(VI) and W(VI) interfere seriously. The method is selective, sensitive and can be applied to the determination of total vanadium in a variety of samples.

19.
Funct Dev Morphol ; 1(2): 53-4, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1790342

RESUMO

The corpuscles of Stannius of Botia lohachata are made up of numerous large lobules, each of which is bounded by a septum and contains two types of cells. The secretory granules are PAS- and AF-positive, indicating that 1,2 glycol groups and non-sulphated mucoid substances are present. Detached cells in the lobule lumen are suggestive of holocrine secretion. The possibility of the existence of more than one secretory product is discussed.


Assuntos
Cipriniformes/anatomia & histologia , Rim/anatomia & histologia , Animais
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