Desorption/ionization on self-assembled monolayer surfaces (DIAMS).
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Letter↗
Biomedical subjects
M Dias
Publications and source records attributed to M Dias.
A new route to trihydroxamate-containing artificial siderophores and synthesis of a new fluorescent probe.
A fluorescent labelled artificial siderophore 1 was synthesized by coupling a 7-nitrobenz-2-oxa-1,3-diazole (NBD) derivative to the terminal amino group of a new trihydroxamate-containing amine 2, a ferrichrome-type siderophore that was obtained from tris(hydroxymethyl)aminomethane. Compound 1 was shown to be a suitable tool for experiments on siderophore transport and uptake processes in various organisms cells and particularly in Candida albicans cells.
Ferrichrome↗
Inter- and intralaboratory variation of in vitro diffusion cell measurements: an international multicenter study using quasi-standardized methods and materials.
In vitro measurements of skin absorption are an increasingly important aspect of regulatory studies, product support claims, and formulation screening. However, such measurements are significantly affected by skin variability. The purpose of this study was to determine inter- and intralaboratory variation in diffusion cell measurements caused by factors other than skin. This was attained through the use of an artificial (silicone rubber) rate-limiting membrane and the provision of materials including a standard penetrant, methyl paraben (MP), and a minimally prescriptive protocol to each of the 18 participating laboratories. "Standardized" calculations of MP flux were determined from the data submitted by each laboratory by applying a predefined mathematical model. This was deemed necessary to eliminate any interlaboratory variation caused by different methods of flux calculations. Average fluxes of MP calculated and reported by each laboratory (60 +/- 27 microg cm(-2) h(-1), n = 25, range 27-101) were in agreement with the standardized calculations of MP flux (60 +/- 21 microg cm(-2) h(-1), range 19-120). The coefficient of variation between laboratories was approximately 35% and was manifest as a fourfold difference between the lowest and highest average flux values and a sixfold difference between the lowest and highest individual flux values. Intralaboratory variation was lower, averaging 10% for five individuals using the same equipment within a single laboratory. Further studies should be performed to clarify the exact components responsible for nonskin-related variability in diffusion cell measurements. It is clear that further developments of in vitro methodologies for measuring skin absorption are required.
Clinical Laboratory Techniques↗
Primary breast lymphoma.
OBJECTIVES: Retrospective evaluation of the clinical behavior, treatment and prognosis in five cases of primary breast lymphoma. METHODS: From 1999 to 2003, five patients with primary breast lymphoma were diagnosed in our department. RESULTS: Primary breast lymphoma (PBL) was diagnosed in five patients, whose median age was 63.4 (41-79) years. In four out of five patients, a diagnosis of lymphoma was made after the evaluation of a palpable breast mass measuring 1.5 to 6 cm. All of them were classified as non-Hodgkin's B cell lymphomas and three of five cases were diffuse large cell lymphomas. All patients were submitted to chemotherapy; in only one patient was surgery performed. CONCLUSIONS: A relatively high rate of PBL was observed in our department compared with other oncology centers. Beyond its scarce appearance, PBL is very difficult to distinguish from primary breast carcinoma. Histology remains the major diagnostic tool.
Adult↗
Detection of axillary metastases in breast cancer patients using ultrasound and colour Doppler combined with fine needle aspiration cytology.
The aims of this study were to evaluate the diagnostic value of ultrasonography and colour Doppler combined with fine needle aspiration (FNA) cytology for the detection of non-palpable axillary lymph node metastases in breast cancer patients. Forty patients with operable breast cancer (T1/T2), invasive carcinoma, not submitted to neo-adjuvant therapy, underwent axillary ultrasonography and colour Doppler preoperatively. FNA cytology was performed on axillary lymph nodes presenting ultrasonographic and/or Doppler suspicious features. A total of 542 lymph nodes were surgically removed from the 40 patients; 19 were metastatic lymph nodes. Ultrasound-guided FNA detected metastases in six out of 11 histologically node-positive patients. Sensitivity and specificity in this preliminary study was 55% and 100%, respectively. These are the preliminary results of a prospective study that has the purpose of reducing the sentinel node procedures in breast cancer patients with clinically negative axillae, but positive FNA cytology.
Adult↗
The effect of solvent on permeant diffusion through membranes studied using ATR-FTIR and chemometric data analysis.
One method of improving the bioavailability of a topical formulation is to add an appropriate solvent that will act as a solubilizer for the permeant and, at the same time, modify the barrier properties of the stratum corneum. It has proved very difficult to determine the precise mechanisms of action involved; this is complicated by the concurrent diffusion of the solvent and the permeant into the skin. Under these circumstances the barrier function may well be changing as a function of time as the solvent disrupts it. We have observed this phenomenon in a model silicone membrane system that we have chosen to study initially to avoid the complexity of the heterogeneous nature of skin and its inherent biological variability. Diffusion experiments were conducted using an established ATR-FTIR approach but the data interpreted using sophisticated chemometric approaches that allowed us to deconvolve the IR signals from the permeant, the solvent, and the membrane. Data are presented that show the concurrent diffusion of benzoic acid (permeant), octanol (solvent), and how the octanol modifies the characteristics of the silicone membrane. Initial data are then presented using human skin to show the power of the diffusion approach coupled to the data deconvolution technique.
Diffusion↗
GARField magnetic resonance profiling of the ingress of model skin-care product ingredients into human skin in vitro.
A preliminary study of the ingress of mineral oil, decanol, and glycerine into samples of human abdominal skin tissue in vitro made using magnetic resonance profiling with a GARField magnet is reported. Two layers, each circa 50 microm thick and attributed to stratum corneum and viable epidermis, are spatially resolved. Clear differences are observed in the magnetic resonance response of these layers arising from the application of the model skin-care product ingredients. In the case of decanol and glycerine, it is suggested that the profiles show evidence for the effects of moisturization, as distinct from hydration. In the case of glycerine, the effective ingress diffusion coefficient is calculated to be 1.3 +/- 0.5 x 10(-9) cm2s(-1).
Epidermis↗
Diagnostic value of ultrasound and color Doppler in identifying axillary lymph node metastases in patients with breast cancer.
PURPOSE: The aim of this study was to evaluate the diagnostic ability of ultrasound and color Doppler in axillary lymph node metastases of patients with breast cancer. MATERIAL AND METHODS: A prospective study including 55 patients with primitive, invasive, node negative breast cancer who underwent preoperative axillary ultrasound and color Doppler. Doppler and morphologic ultrasound criteria were applied to the identification of axillary lymph node metastases. RESULTS: The imagery study of all 55 patients identified a total of 141 nodes; 44 were considered to be positive according to established criteria. The histological examination of the axillary dissection revealed a total of 989 nodes; 77 out of 989 presented metastases; all invaded nodes belonged to 21 patients. The previous imagiologic study was positive for axillary lymph node metastases in 15 out of these 21 patients. A sensitivity of 71.4%, a specificity of 71.4%, a negative predictive value of 80.6% and a positive predictive value of 60.0% were achieved. CONCLUSION: The imagery study of the axillary region through ultrasound and color Doppler might be useful in assessing axillary lymph node metastases in patients with breast cancer.
Breast Neoplasms↗
Structural elucidation of natural 2-hydroxy di- and tricarboxylic acids and esters, phenylpropanoid esters and a flavonoid from Autonoë madeirensis using gas chromatographic/electron ionization, electrospray ionization and tandem mass spectrometric techniques.
The chemical composition of Autonoë madeirensis bulbs was characterized as part of a systematic phytochemical study of this species. The compounds reported were mainly identified on the basis of gas chromatography/electron ionization, electrospray ionization and tandem mass spectrometry. The structures of the pure compounds were also characterized by means of other physical and spectroscopic data (m.p., IR, UV, NMR). The compounds identified were 2-hydroxy di- and tricarboxylic acids and esters (malic acid, citric acid and their methyl and ethyl esters), cis- and trans-hydroxycinnamic esters (methyl and ethyl p-coumarate and methyl ferulate) and a new flavone diglucoside, 7-O-[beta-glucosyl-(1-->2)-O-beta-glucosyl]apigenin, the interglucosidic linkage (1-->2) of which is, to the best of our knowledge, reported for the first time in a diglucoside of apigenin. The results may contribute to the chemotaxonomy of the Autonoë genus and lead to a rapid tool for the systematic characterization of these compounds in plant extracts.
Chromatography, Gas↗
ATR-FTIR spectroscopic investigations on the effect of solvents on the permeation of benzoic acid and salicylic acid through silicone membranes.
The effect of a series of alcohols on the permeation of salicylic acid (SA) and benzoic acid (BA) through silicone membrane was evaluated, using Franz-type diffusion cells. Although permeants were applied at the same thermodynamic activity in all vehicles, the resulting fluxes were found to differ significantly. This was a consequence of the interactions between the vehicles and the membrane. The interactions between the vehicles and the membrane were further investigated using ATR-FTIR spectroscopy. With this technique, it was possible to identify two different diffusion processes when the membrane was pre-treated with buffer, whereas one single diffusion process was observed when the membrane was pre-soaked with the vehicle. The technique was successfully used to deconvolute the relative magnitude of partition and diffusion in the permeation process. It was shown that the permeation of both acids was affected by the effect of the vehicles on the diffusion coefficient and the partition coefficient in the silicone membrane. The solubility of the drug in the impregnated membrane was found to be proportional to the saturated solubility in the vehicle used to treat the membrane. The solubility of BA in the impregnated silicone membrane was twice that of SA.
Antifungal Agents↗
The road to success in PPS: guiding care for efficiency and effectiveness. Prospective payment system.
This article features one organization's attempt to interpret and form operational definitions for the initiation of the prospective payment system (PPS) by October 1, 2000. Data collection, initiated with the October 28, 1999, proposed regulations, showed inconsistent use of resources when patient needs were similar based on the initial 20 indicators used to calculate acuity and payment levels in PPS. A decision to use a clinical guidance system with the potential to control outcomes and use rates resulted in the development of a system called Care Guides. These tools help home care staff develop and implement efficient and effective home care plans.
Attitude of Health Personnel↗
Continuous remifentanil for pediatric neurosurgery patients.
OBJECTIVE: Remifentanil hydrochloride is a new titratable opioid agonist with rapid onset and offset of action. We present 2 cases of intracranial mass lesions in whom remifentanil was used to obtain serial neurological examinations. METHODS: Patients received bolus doses of remifentanil 1 microgram/kg followed by continuous infusions of 0.1-0.5 microgram/kg/min, titrated to effect. After the clinical examination, the remifentanil was restarted to the desired effect. CONCLUSION: The ultra-short duration of action of remifentanil makes it ideally suited for selected pediatric neurosurgical patients in whom frequent, serial neurological examinations are necessary. There were no side effects associated with the use of remifentanil.
Anesthetics, Intravenous↗
Effects of lead counseling for children with lead levels > or = 20 microgram/dL: impact on parental knowledge, attitudes, and behavior.
The purpose of this study was to assess parental knowledge, attitudes, and behavior concerning lead reduction counseling. Of 108 children with confirmed venous lead levels > or = 20 microg/dL, 75 (69%) of the parents were interviewed by telephone 6-9 months later. The majority of parents recalled being given specific lead reduction strategies. Knowledge of cleaning interventions was associated with parents who could state the lead level, who perceived a benefit from knowing it was elevated, and whose children were referred to a specialty lead clinic. Recall of nutritional interventions was associated with parents who could state the lead level and whose children were referred to a specialty lead clinic. Although 79% of parents thought that it was beneficial to know their child's lead level was elevated, only 65% reported implementing lead reduction strategies. The majority of parents recalled receiving lead reduction counseling but reported low compliance with lead reduction strategies. Further research is needed to determine the causes of the discrepancy between knowledge and making the behavior changes necessary to comply with lead reduction interventions.
Child, Preschool↗
Topical delivery of caffeine from some commercial formulations.
Permeation of caffeine through human skin and artificial membranes (mounted in modified Franz type diffusion cells) was evaluated, either from saturated solutions or from commercially available topical formulations (all containing 3% caffeine). Data interpretation of the caffeine diffusion through human skin does not implicate transfer through pores despite caffeine being a relatively polar molecule. No correlation was found between transfer though the synthetic membranes (cellulose acetate impregnated with isopropyl myristate and silicone rubber soaked in isopropyl myristate) and that observed through skin. The synthetic membranes can be used for assessing product performance in quality assurance but will give little indication of its performance in vivo. The study investigated the percutaneous permeation of caffeine through human skin in order to obtain a mechanistic interpretation of its route of permeation. Synthetic membranes were also examined to determine if they could be used as models for human skin. Different commercial formulations investigated to determine the significance of enhancement strategies.
Administration, Topical↗
Glycogen storage disease type IV presenting as hydrops fetalis.
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Diagnosis, Differential↗
Benign and malignant mammary tumors induced by DMBA in female Wistar rats.
This study pretends to characterize 7, 12-dimetylbenz[a]anthracene-induced benign and malignant tumors. One hundred and twenty female Wistar rats were randomly allocated to two groups: Control Group and Induction Group; IG animals were given a single dose of DMBA and killed 24 weeks after. Other tumors besides breast tumors were diagnosed, mainly tumors of the salivary glands and ovarian benign epithelial tumors. Incidence of breast disorders was about 60%. Macroscopic mammary tumors varied in dimension from 2 mm to 55 mm. Malignant breast tumors (n = 56) were essentially invasive ductal carcinomas (91.1%), G1 (92.2%), presenting histologic characteristics of good prognosis. Predominant benign breast disorders consisted of glandular (68.6%) and atypical (20%) hyperplasias reproducing histologic types of human breast diseases. Different individual susceptibility to DMBA apparently occurs; while some rats never developed neoplasias, others exhibited several tumors.
9,10-Dimethyl-1,2-benzanthracene↗
Sinusitis-associated epidural abscess presenting as posterior scalp abscess--a case report.
Complications of paranasal sinusitis constitute true surgical and medical emergencies. These complications appear to be more prevalent and seem to present in a more fulminant manner in the pediatric age group. The most common complication of paranasal sinusitis is orbital cellulitis followed collectively by all the intracranial complications. These include meningitis, subdural empyema, intracerebral abscess, epidural abscess and rarely cavernous or superior sagittal sinus thrombosis. We report the case of a 7-year old boy who presented with posterior scalp cellulitis and abscess as a complication of minimally symptomatic paranasal sinusitis. A combined neurosurgical and otolaryngologic approach was required to treat a unilateral ethmoid and frontal sinusitis associated with an epidural abscess abutting the length of the superior sagittal sinus and a posterior subgaleal abscess. The pertinent anatomy allowing for the development of this disease process is discussed. The danger of neurologic sequellae resulting from thrombosis of the superior sagittal sinus is emphasized. Aggressive treatment utilizing a multi-disciplinary surgical approach as well as broad spectrum antibiotics is paramount to obtain the best chance for a full recovery.
Abscess↗