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Biomedical subjects

L Montanari

Publications and source records attributed to L Montanari.

At least 109 records · Page 6Linked to original sources
PubMed1976

[Phytotoxic activity of triazene derivatives. VI. 1-aryl-3-arylalkyl-3-alkyltriazene derivatives].

A series of of 1-aryl-3-arylalkyl-3-alkyltriazenes (B) was prepared and studied for phytotoxic activity. The previously unknown substances [Table I: substances (I leads to XVI)] were prepared by condensation of the appropriate diazonium salt with the required secondary amine in an alkaline medium and were tested against five representative plant species in both pre- and post-emergence tests at a dose of 6 kg/ha. All the substances studied were inactive in pre-emergence tests. However most of the compounds showed phytotoxic activity by absorption through the foliage. This activity was not very pronounced and always lower than triazene analogs previously studied (type A compounds) which have no aralkyl residue on nitrogen 3.

Herbicides↗
PubMedDate not supplied

Systemic nicotine exposure in tobacco harvesters.

Several epidemics of nicotine intoxication have been described among tobacco harvesters; however, little is known about nicotine absorption under typical working conditions. To assess systemic nicotine absorption during a regular working shift, the authors performed an observational field study. Included in the study were 10 healthy, nonsmoking, female tobacco harvesters and a control group of 5 healthy, nonsmoking, female hospital workers. Nicotine and cotinine were measured in sequential samples of blood and urine during a regular workshift. Blood nicotine levels rose from a nadir value of 0.79 +/- 0.12 ng/ml to a peak value of 3.45 +/- 0.84 ng/ml (p < .05 [Tukey's modified t test]) in the exposed group. In the control group, levels were stable at 0.1 +/- 0.1 ng/ml (p < .01). Moreover, the mean blood nicotine level measured 3 mo following the end of exposure in 6 of 10 exposed subjects was 0.24 +/- 0.12 ng/ml (p < .01). Corresponding higher values of urine nicotine and urine cotinine were observed in the exposed versus control group (comparative p values were < .01 and < .05, respectively). Overall, tobacco harvesters absorbed approximately 0.8 mg of nicotine daily. Given that nicotine can induce adverse health effects, the authors believe that prevention of nicotine absorption in tobacco harvesters should be sought and that workers should be informed about occupational risks.

Adult↗
PubMedDate not supplied

Formulation study and anti-inflammatory efficacy of topical semi-solids containing a nitro ester of flurbiprofen.

A new nitro-oxybutylester of flurbiprofen (NO-FP) is a promising anti-inflammatory drug in the treatment of dermatological disorders, and the feasibility of its cutaneous administration was evaluated. Four different semi-solid formulations were evaluated in order to assess the influence of the composition on the drug amount retained in the stratum corneum and epidermis (SCE). The lipophilic ointment induced the highest NO-FP amount retained in the SCE and, therefore, skin permeation enhancers (Transcutol), Lauroglycol), oleic acid and isopropyl myristate) were added to this formulation. The in vitro NO-FP amounts retained in the SCE were correlated with the solubility parameters, and a good linear correlation was found (r(2) = 0.925). The formulation of the lipophilic ointment was optimized, and the activity of this preparation was verified in methyl-nicotinate-induced contact urticaria and UV-induced erythema obtaining good results in terms of efficacy and safety.

Administration, Cutaneous↗
PubMedDate not supplied

Clonazepam microencapsulation in poly-D,L-lactide-co-glycolide microspheres.

The work is aimed at the preparation and characterization of biodegradable microspheres of poly-D,L-lactide-co-glycolide (PLGA), for the controlled release of clonazepam. The solubility characteristics of this drug make it an interesting example to evaluate the performances of the two most widely used microencapsulation techniques, emulsification solvent evaporation and spray-drying. Several biodegradable PLGA copolymers have been evaluated (RG 502H, RG 503H, RG 503, Boerhinger Ingelheim). They differ in terms of molecular weight and physico-chemical characteristics. The microspheres obtained have been characterized for their morphology, physico-chemical properties (DSC) and in vitro dissolution behaviour. Between the two preparation methods, only spray-drying was suitable for the microencapsulation of clonazepam in PLGA microspheres. In vitro dissolution tests highlight that more sustained release of drug is achieved with the higher (molecular weight) polymer.

Anticonvulsants↗
PubMedDate not supplied

Evaluation of adhesive properties of transdermal therapeutic systems containing nitroglycerin.

The patch performances and the success of the transdermal drug delivery can be significantly affected by the quality of contact between the patch and the skin. Poor adhesion will dramatically reduce percutaneous delivery. In this study the adhesive properties (peel force and creep resistance) of three monolayer self-adhesive nitroglycerin (NTG) patches available on the market, Deponit, Minitran, and Triniplas, were compared. The patches were characterized also in terms of in vitro drug release and ex vivo skin permeation. The creep resistance values verified in the case of Deponit and Triniplas indicated a low cohesion of these matrices. The peel force values were in the accepted range, even if Triniplas and Deponit showed values double that shown by Minitran. The percentage of NTG released in vitro after two hours in all cases exceeded ninety percent. The ex vivo permeation profiles were similar, even if the three patches had different loaded amounts and surface areas. The measured permeated amount, 11 mg permeated in 24 h, was predictive of the claimed in vivo release (10 mg in 24 h).

Adhesiveness↗
PubMedDate not supplied

99mTc-MAG3 versus 131I-orthoiodohippurate in the routine determination of effective renal plasma flow.

99mTc-mercaptoacetyltriglycine (MAG3) has been proposed as an alternative to 131I-orthoiodohippurate (OIH) for the scintigraphic determination of effective renal plasma flow (ERPF). The purpose of this study was to compare the ERPF values determined simultaneously with MAG3 and OIH by a dual channel technique in a large group of subjects with widely ranging renal function. During the last two years, we administered a simultaneous injection of 74 MBq of MAG3 and 0.74 MBq of OIH to each subject who underwent a renal scintigraphic study in our hospital. They were 53 females and 50 males (mean age: 52 years; range: 18-70 years), either normal (30) or with a diagnosis of essential hypertension (53), chronic renal failure (14), renal calculi (5), or renal transplant (1). Plasma clearance and ERPF were calculated with both radiocompounds by using the exponential formula of Tauxe and coworkers and a single plasma concentration determination sampled 44 min after injection of the two tracers. The time-activity curves for kidney and blood were of the same bi-exponential type. The mean ratio between the two plasma clearances was 0.49. The linear regression of the ERPF values obtained with the two radiocompounds was highly significant (r = 0.69; p less than 0.0001) and is expressed by the equation: ERPF (MAG3) = 0.453 ERPF (OIH) + 25.7. These data suggest that the routine calculation of ERPF from MAG3 clearance is consistent with the results obtained from OIH clearance. In conclusion, MAG3 appears to be a good predictor of ERPF in routine clinical practice.

Adult↗
PubMedDate not supplied

Aspiration of ovarian cysts: laparoscopy or echography?

The authors present their experience from 1970 to the present on the laparoscopic aspiration of ovarian cysts and compare it with the more recent echographic aspiration technique. Since the risks of the aspiration of neoplastic masses cannot yet be evaluated, a strict selection of patients was carried out in order to perform the diagnostic and therapeutic aspiration of presumably benign masses. In addition, endometrial cysts were not included in the follow-up since these will be the object of a future communication, nor were dermoid cysts, removed during surgery itself. Out of 45 cases of laparoscopic aspiration with a follow-up ranging from 6 months to 4 years, 5 recurrences were observed, while the 15 cases of echographic aspiration (follow-up from 6 to 18 months) had 8 recurrences. We therefore believe that the latter, less invasive method, should be employed for diagnostic purposes only, while the laparoscopic method, which is more invasive and more traumatic, should be used when it is desirable to obtain also a therapeutic result.

Adult↗
PubMedDate not supplied

Laparoscopic ovarian biopsy in hypergonadotropic amenorrhea.

After reviewing the different etiopathogenetic hypotheses of hypergonadotropic amenorrhea, the AA. describe six clinical cases, four of which classifiable as early menopause and two as syndrome of resistant ovary. The basic role of laparoscopic ovarian biopsy in the attainment of a correct diagnosis is emphasized. Prognosis in terms of fertility is related to the residual follicular endowment which, even when extremely low, justifies a stimulating treatment, as demonstrated in the case reported in detail.

Adult↗
PubMedDate not supplied

Successful pregnancy following gonadotropin therapy in a young female with juvenile idiopathic hemochromatosis and secondary hypogonadotropic hypogonadism.

Heart failure and hypogonadotropic hypogonadism are the most frequent clinical problems encountered in patients with juvenile idiopathic hemochromatosis (JIH). In this context, amenorrhea is one of the first symptoms in female patients, and hormone therapy must be added to phlebotomy to restore menstrual cycles. Here we report the case of a woman in childbearing age with hypogonadotropic hypogonadism due to JIH. Following therapy with gonadotropinic hormones the patient had a twin pregnancy with term delivery. The newborns presented a normal iron status. This confirms that early diagnosis and treatment of JIH are important to prevent irreversible organ damage and shows that the female reproductive function can be preserved in adequately treated patients.

Adult↗
PubMedDate not supplied

Evaluation of the influence of open and closed-ampoule technologies on particulate matter in small-volume parenterals.

SVP in glass ampoules are manufactured using two main different technological production processes: the open-ampoule process (O) and the closed-ampoule process (C). In principle, the open-ampoule production technology should lead to better controlled production process. To test this hypothesis and quantify the possible qualitative differences in the manufactured ampoules, a suitable experimental design was set up. The two ampoule production processes have been compared on the basis of the visible particulate burden. Two batches of ampoules filled with water for injections were produced for each type of process, following conventional industrial procedures. Two samples of 20,000 units were taken from each batch and inspected with different automatic inspection systems: two Brevetti CEA machines (S1, S2--light scattering) and two EISAI machines (S3, S4--light absorbtion). The comparison between the processes was based on the rejection percentage. On both inspection machines the open-ampoule production samples present rejection percentages (ranging from 0.154% to 1.248% rejection percentages) which, on average, are lower than those detected in closed-ampoule production (ranging from 1.434% to 3.86% rejection percentages). The difference between the two processes is even more marked if we also consider the data obtained using inspection machines S3 and S4. The substantial differences in performance of the four inspection machines stress the need to provide for adequate validation procedures.

Drug Contamination↗
PubMedDate not supplied

Characterization of the biophysical properties of human erythroblasts as a preliminary step to the isolation of fetal erythroblasts from maternal peripheral blood for non invasive prenatal genetic investigation.

BACKGROUND AND OBJECTIVE: Fetal erythroblasts in maternal circulation represent a valuable source of fetal cell material which can be obtained with non-invasive procedures that do not endanger the fetus. Physical separation techniques have been invaluable in the isolation and characterization of different cells. There are basically two principles that have been used most successfully: separation according to density and separation according to size. In order to determine whether physical separation procedures are capable of purifying human erythroblasts, the biophysical characteristics of these cells were determined. METHODS: Bone marrow particles were obtained from formal adults and peripheral blood buffy coats from blood banks. A single cell suspension was initially fractionated by buoyant density gradient centrifugation. Fractions enriched in erythroblasts were pooled and further processed by velocity sedimentation in order to take advantage of the differences in size of erythroblasts and other cells. RESULTS: Density distribution curves were drawn after density gradient centrifugation for the different cell types present in the starting cell samples. Separation of the erythroblast-enriched density fractions by velocity sedimentation was successful and a highly purified population of erythroblasts was obtained. Cell size distribution of the different cell types was determined. INTERPRETATION AND CONCLUSIONS: This initial study defines the biophysical properties (size and density) of human erythroblasts in bone marrow and peripheral blood and is a necessary preliminary step in setting up the optimal procedure for the isolation of fetal erythroblasts from maternal peripheral blood in sufficient amounts and purity for prenatal non-invasive genetic investigation.

Adult↗
PubMedDate not supplied

Buccoadhesive tablets for the slow delivery of cetylpyridinium chloride: design and in vitro/in vivo analysis.

A buccoadhesive slow-release system constituted by a monolayer tablet was developed for the administration of cetylpyridinium chloride (CPC). Tablet composition was based on a mixture of a bioadhesive polymer with conventional excipients. Three different polymers (Methocel K4M, Noveon AA1, Carbopol 974P) in three different concentrations (10%, 20%, 30%) were used. The release profile and the adhesion properties of nine formulations were evaluated in vitro. Based on these results three formulations containing 10% w/w of the tested polymers were chosen to assess, with preliminary in vivo studies, the compliance and the residence time in the month of the systems. Tablets containing Noveon AA1 showed the best performances.

Adult↗