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Biomedical subjects

M Trotta

Publications and source records attributed to M Trotta.

At least 37 records · Page 2Linked to original sources
PubMed1997

Chronic intestinal infection due to subgenus F type 40 adenovirus in a patient with AIDS.

A case of chronic intestinal infection due to adenovirus type 40 lasting for 13 months in a patient with AIDS is described. Adenovirus particles were detected by electron microscopy in biopsy samples taken from the duodenum 3 months after the onset of diarrhoea. The virus was identified as adenovirus type 40 in stool samples by ELISA monoclonal antibodies to adenovirus group antigen (MAd-g2) and types 40 and 41 (MA 40-1 and MA 41-1). No other enteropathogens were found. These data support a causal relationship between adenovirus 40 and the gastrointestinal symptoms of the patient. This is the first reported case of intestinal infection caused by adenovirus type 40 in a patient with AIDS.

AIDS-Related Opportunistic Infections↗
PubMed1997

Effect of oil phase composition on the skin permeation of felodipine from o/w microemulsions.

Oil/water microemulsions containing benzyl alcohol or different ratios of benzyl alcohol and isopropyl myristate as oil phase were prepared and used as vehicles for the transdermal absorption of felodipine. Skin permeation from the microemulsions was compared with that from a drug suspension in an apparent external phase of a microemulsion and with an aqueous drug suspension. The highest flux was from the microemulsion with the highest solubility of felodipine, while the permeation rate decreased over time from the suspension in the apparent external phase. The flux from the aqueous suspension was 10-50 times lower than that from the microemulsions. These results indicate that microemulsions containing benzyl alcohol may be interesting vehicles for transdermal administration of felodipine.

Administration, Cutaneous↗
PubMed1997

[Azithromycin combined with pyrimethamine in the treatment of neurotoxoplasmosis, in an AIDS patient].

We report one case of successful treatment of cerebral toxoplasmosis in acquired immunodeficiency syndrome (AIDS) with azithromycin combined with pyrimethamine. Toxoplasmic encephalitis had been diagnosed on the basis of multiple lesions exhibiting ring like contrast enhancement on double contrast Computed Tomographic (CT) scan of the brain. Thereby our patient had been treated with pyrimethamine 25 mg/die, after an attack dose of 100 mg in the first day, and clindamycin 2400 mg/die, because of sulfa-drug allergy, but clindamycin had to be discontinued because of rash development. At this point azithromycin, at a dose of 1000 mg/die for 21 days and 1500 mg a week for the following 50 days of follow-up, was added to pyrimethamine. Follow-up CT scan after 20 days of treatment (10 with clindamycin+pyrimethamine and 10 with azithromycin+pyrimethamine) revealed partial resolution of the brain lesions and subsequently (after 50 and 80 days of treatment) complete resolution.

AIDS-Related Opportunistic Infections↗
PubMed1996

Role of palmitic acid on the isolation and properties of halorhodopsin.

Purified halorhodopsin was isolated from Halobacterium halobium as previously described (Duschl, A. et al. (1988) J. Biol. Chem. 263, 17016-17022). Two purple bands were eluted from phenyl-Sepharose column, indicating the presence of differently retained halorhodopsin forms; the absorption spectra of the two halorhodopsin bands in the dark were not different. By gas chromatography/mass spectrometry we could identify palmitate (which is only a minor lipid component of archaeal cells) among lipids associated with purple fractions. Typically the palmitate content of the first eluted band was higher than that of the second, indicating a correlation between the palmitate content and the retention time; from one to two fatty acid molecules per halorhodopsin molecule were present depending on the fraction analysed. Very little or no palmitate was released from denatured halorhodopsin. By adding palmitate to buffers used in the phenyl-Sepharose chromatography, only one sharp purple band was collected, corresponding to the less retained halorhodopsin fraction. Pentadecanoic fatty acid could also affect the halorhodopsin chromatography. Chromatography of halorhodopsin in the presence of beta-mercaptoethanol showed only one band, corresponding to the more retrained halorhodopsin form. The two halorhodopsin fractions had different photoreactivity; the less retained halorhodopsin fraction (at higher palmitate content) showed an higher rate of decay of the absorbance at 570 nm upon illumination. By following the decay of the absorbance at 570 nm upon addition of alkali in the dark, we found that the two halorhodopsin fractions had different pKa values of deprotonation.

Bacteriorhodopsins↗
PubMed1996

Influence of counter ions on the skin permeation of methotrexate from water--oil microemulsions.

The influence on the permeation of methotrexate across intact hairless mouse skin of different counter ions added to water--oil (w/o) microemulsions containing lecithin, as surfactant, and water--propylene glycol at different pH values, as internal phase, was studied. As counter ions, monooctyl phosphate, monodecyl phosphate, monodecyl glycerophosphate, taurodeoxycholate, dodecyl sulfate and dioctyl sulfosuccinate were used. At pH 4.0, the transport of methotrexate was enhanced by the counter ions and a marked increase in the flux of the drug was measured when dodecyl sulfate and dioctyl sulfosuccinate were used. At pH 5.0 only a slight increase of the flux was observed. The increased permeation was attributed to the lipophilization of methotrexate as a consequence of ion pair formation.

Animals↗
PubMed1996

Human parvovirus B19 infection within a family and risk for pregnant women.

During an outbreak of parvovirus B19 infection among four related families at least 70% of the household contacts, including a woman at the 33rd week of pregnancy, became infected. Twins were born at the 39th week of pregnancy, both with B19 infection. B19 DNA was detected in their sera by a nested PCR, anti-B19 IgM was detectable only by an immunofluorescence assay, and low levels of maternal anti-B19 IgG were demonstrable by an immunoenzymatic test in the serum of both children. All the haematological parameters were normal at birth and 6 months later, when B19 DNA and anti-B19 antibody were no longer detectable in serum samples. This observation emphasizes the high risk of B19 infection among household contacts and the possibility of a favourable outcome of the foetal infection, possibly related to infection late in the pregnancy.

Adult↗
PubMed1996

[Progressive paralysis. A case report].

STUDY OBJECTIVE: A fairly uncommon case of neurosyphilis is reported in a not immunocompromised patient. CASE REPORT: A case of general paresis in a 40 year-old male with the recent onset of mania is described. Psychiatric anamnesis was negative. Neurologic examination was negative. Laboratory tests were performed and serologic tests for syphilis were positive. Cerebrospinal fluid (CSF) examination showed 80 leukocytes/mm3, a reactive Venereal Disease Research Laboratory (VDRL) and normal protein concentration. CSF gamma globulin with an oligoclonal pattern and abnormal IgG index were found. A test for antibodies to Human Immunodeficiency Virus (HIV) was negative. The patient underwent a high dose intravenous penicillin G regimen for two weeks. A follow-up six months later showed a normal CSF even though the IgG index was still abnormal and the mental status was unchanged. CONCLUDING REMARKS: The authors suggest that patients with neurologic and/or psychiatric symptoms with a recent onset and a reactive VDRL should undergo a CSF examination to exclude a possible neurosyphilis.

Adult↗
PubMed1995

Pseudo-ternary phase diagrams of lecithin-based microemulsions: influence of monoalkylphosphates.

The formation of macroscopically homogeneous, stable, fluid, optically transparent, isotropic solutions (microemulsions) was delineated, at 25 degrees C, for systems containing water, soybean lecithin, sodium monoalkylphosphate (hexyl or ocytl), alcohol and isopropyl myristate. Six straight or branched alcohols (1-butanol, 2-butanol, isobutanol, 1-pentanol, 2-pentanol, 3-pentanol) were investigated as co-surfactants. A constant lecithin/alcohol mixing ratio was used, while the aqueous phase consisted of a solution of alkylphosphates at different concentrations. An increase of the microemulsion domain was seen by increasing the concentration of the alkylphosphate. With 0.2m hexylphosphate, as aqueous phase, the microemulsion domain consisted of a single, region, that, in the presence of butylic alcohols, spanded the greater portion of the phase diagram. In the presence of amyl alcohols the area of this region was much smaller. With 0.2 m octylphosphate the realm of existence of the microemulsions, except for 1-pentanol, consisted of two regions separated by a liquid-crystal region. With all the alcohols examined, the liquid-crystal phase solubilized a larger amount of oil in the presence of octylphosphate than in the presence of hexylphosphate. The stability ranges of microemulsions in systems containing soybean, lecithin, alcohol, water, and isopropyl myristate can be greatly increased by using a second hydrophobic amphiphile, such as hexylphosphate, to adjust the hydrophilic-lipophilic balance or the spontaneous peaking properties of lecithin-alcohol systems.

Chemistry, Pharmaceutical↗
PubMed1995

Use of furazolidone for the treatment of microsporidiosis due to Enterocytozoon bieneusi in patients with AIDS.

The efficacy of furazolidone for treatment of intestinal microsporidiosis due to Enterocytozoon bieneusi was studied in three patients with AIDS. All patients had chronic diarrhoea and weight loss. Mean CD4 cell count was 34.6/mm3. A course of furazolidone (100 mg orally four times a day) was given for 20 days. The drug was well tolerated and neither side effects nor alterations in the laboratory parameters were noted. Diarrhoea ceased within a mean of 12 days of starting treatment and clearance of microsporidian shedding in stool was observed. In one of the patients, however, symptomatic microsporidiosis recurred. Therefore furazolidone seems to have a transient but significant effect on intestinal infection due to Enterocytozoon bieneusi.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Inhibition of lipoperoxidation of linoleic acid by five antioxidants of different lipophilicity.

The efficacy of oxidation inhibition of five natural and synthetic antioxidants (BHT, BHA, nordihydroguaiaretic acid (NDGA), quercetin and rutin) was studied in O/W emulsions. Linoleic acid was used as a reference molecule; the reaction was initiated by an azo-compound. The kAH characterizing the reaction of the antioxidant with the peroxyl radical decreases in the following order: kAH(BHA) > kAH(BHT) > kAH(NDGA) > kAH(quercetin) > kAH(rutin).

Antioxidants↗
PubMed1993

Calorimetric study on the solubilization of butanol by alkylphosphate and alkylphosphate-lecithin systems.

Microcalorimetric studies on alkylphosphate-butanol and alkylphosphate-butanol-lecithin systems were carried out as a first step to study the role of butanol (used as cosurfactant) in the formation of microemulsions. The enthalpy of solubilization; delta H, of the same amount of butanol (1.806 mol kg-1) in aqueous sodium monoalkyl-phosphates, with a hydrocarbon chain varying from 6 to 10 carbon atoms, was investigated as a function of alkylphosphate concentration. Measurements were performed in the presence and in the absence of lecithin. The enthalpy values measured upon addition of butanol to the mixtures were negative in all cases. Below the critical micelle concentration (CMC) of the alkylphosphates, the heats of butanol dissolution were found to decrease upon increasing the concentration of the alkylphosphate. This behaviour was related to the dissolution of butanol in water and to the formation of mixed butanol-alkylphosphate and butanol-alkylphosphate-lecithin micelles. Above the CMC essentially constant delta H values were found. The delta H measured may be the sum of simultaneous effects--heat of alcohol dissolution and the simple alkylphosphate micelle dissociation or alkylphosphate-lecithin mixed aggregate dissociation and the heat of mixed micelle formation. The delta H at the plateaus were linearly related to the corresponding CMC values of the alkylphosphates.

Butanols↗
PubMed1991

Temperature dependence of charge recombination from the P+QA- and P+QB- states in photosynthetic reaction centers isolated from the thermophilic bacterium Chloroflexus aurantiacus.

The temperature dependence of charge recombination from the P+QA- and from the P+QB- states produced by a flash was studied in reaction centers isolated from the photosynthetic thermophilic bacterium Chloroflexus aurantiacus. P designates the primary electron donor; QA and QB the primary and secondary quinone electron acceptors respectively. In QB-depleted reaction centers the rate constant (kAP) for P+QA- recombination was temperature independent between 0-50 degrees C (17.6 +/- 0.7 s-1 at pH 8 and pH 10). The same value was obtained in intact membranes in the presence of o-phenanthroline. Upon lowering the temperature from 250 K to 160 K, kAP increased by a factor of two and remained constant down to 80 K. The overall temperature dependence of kAP was consistent with an activationless process. Ubiquinone (UQ-3) and different types of menaquinone were used for QB reconstitution. In UQ-3 reconstituted reaction centers charge recombination was monoexponential (rate constant k = 0.18 +/- 0.03 s-1) and temperature independent between 5-40 degrees C. In contrast, in menaquinone-3- and menaquinone-4-reconstituted reaction centers P+ rereduction following a flash was markedly biphasic and temperature dependent. In menaquinone-6-reconstituted reaction centers a minor contribution from a third kinetic phase corresponding to P+QA- charge recombination was detected. Analysis of these kinetics and of the effects of the inhibitor o-phenanthroline at high temperature suggest that in detergent suspensions of menaquinone-reconstituted reaction centers a redox reaction removing electrons from the quinone acceptor complex competes with charge recombination. Instability of the semiquinone anions is more pronounced when QB is a short-chain menaquinone. From the temperature dependence of P+ decay the activation parameters for the P+QB- recombination and for the competing side oxidation of the reduced menaquinone acceptor have been derived. For both reactions the activation enthalpies and entropies change markedly with menaquinone chain length but counterbalance each other, resulting in activation free energies at ambient temperature independent of the menaquinone tail. When reaction centers are incorporated into phospholipid vesicles containing menaquinone-8 a temperature-dependent, monophasic, o-phenanthroline-sensitive recombination from the P+QB- state is observed, which is consistent with the formation of stable semiquinone anions. This result seems to indicate a proper QB functioning in the two-subunit reaction center isolated from Chlorflexus aurantiacus when the complex is inserted into a lipid bilayer.

Bacteria↗
PubMed1991

Doxorubicine englobed in polybutylcyanoacrylate nanocapsules: behaviour in vitro and in vivo.

Nanocapsules of polybutylcyanoacrylate containing doxorubicine were prepared from w/o microemulsion. A concentration of about 10% of the drug was obtained. After washing, dispersion and lyophilization of the nanocapsules, some experiments were performed in vivo and in vitro. About 1% of doxorubicine was released in vitro in 48 hours; after injection on the hairless back of rabbits, the nanoparticles without the drug gave any inflammatory processes, while the nanocapsules containing doxorubicine gave a deeper and more prolonged ulcer than that of the same amount of doxorubicine in solution, indicating that practically all the drug was inside the nanocapsules.

Animals↗
PubMed1989

Microemulsions as topical delivery vehicles: ocular administration of timolol.

The topical administration of timolol as an ion-pair with octanoate was achieved by use of an oil-in-water microemulsion containing lecithin as a surfactant. The microemulsion, a solution of the ion-pair and a solution of timolol alone were instilled in the conjunctival sac of rabbits. A rapid method for the separation and determination of timolol in aqueous humour by HPTLC was used. The bioavailability of timolol from the microemulsion and the ion-pair solution was higher than that obtained from timolol alone. The areas under the curve for timolol in aqueous humour after administration of the microemulsion and the ion-pair solution were 3.5 and 4.2 times higher, respectively, than that observed after the administration of timolol alone.

Absorption↗