Biomedical subjects

M L Colombo

Publications and source records attributed to M L Colombo.

At least 19 recordsLinked to original sources

PubMed1996

Pharmacological activities of Chelidonium majus L. (Papaveraceae).

Chelidonium majus L. (Papaveraceae) has a long history as being useful for the treatment of many diseases in European countries. This plant is of great interest for its use also in Chinese herbal medicine. The plant contains, as major secondary metabolites, isoquinoline alkaloids, such as sanguinarine, chelidonine, chelerythrine, berberine and coptisine. Other compounds structurally unrelated to the alkaloids have been isolated from the aerial parts: several flavonoids and phenolic acids. C. majus extracts and its purified compounds exhibit interesting antiviral, antitumour and antimicrobial properties both in vitro and in vivo.

Alkaloids↗

PubMed1993

Bioactivity of flurithromycin and other macrolides against intracellular susceptible staphylococci.

The intracellular activity of flurithromycin, erythromycin, roxithromycin and miocamycin against susceptible clinical isolates of Staphylococcus aureus, phagocytosed by human monocytes, was investigated. Intracellular bioactivity was studied in a 24-hour assay, using experimental conditions which allowed the intracellular growth of bacteria. A colony counting method was used to differentiate between intracellular bacteriostatic and bactericidal activity of antibiotics. Moreover, the effect of macrolides against extracellular staphylococci was assessed. All agents showed higher intracellular than extracellular activity against staphylococci. At low concentration (0.1 mg/l) they had intracellular bacteriostatic activity. At concentrations higher than the minimal inhibitory ones (1 and 5 mg/l), miocamycin only still produced a bacteriostatic effect while flurithromycin, erythromycin and roxithromycin also showed intracellular bactericidal activity.

Anti-Bacterial Agents↗

PubMed1992

Uptake of flurithromycin by human polymorphonuclear phagocytes: partial characterization of the entry mechanism.

The ability of flurithromycin and erythromycin to enter human polymorphonuclear phagocytes were studied and compared by a velocity centrifugation gradient technique. Both macrolides were markedly concentrated by human cells and attained cellular to extracellular concentration ratios (C/E) > or = 10. The incorporation was rapid and essentially complete after 60 min incubation. When PMNs were pretreated with formaldehyde, or incubated at low temperatures (4-25 degrees C) or at low pH, the transport ratios of both molecules were reduced. Sodium fluoride and 2,4-dinitrophenol, which decreased erythromycin uptake, did not affect flurithromycin penetration. Perturbation of cell membrane by phorbol myristate acetate, but not by formyl methionyl leucyl peptide, affected C/E ratios of both antibiotics. The addition of amino acids or nucleosides did not influence their transfer into PMNs.

Adult↗

PubMed1990

Increased coronary tone in exertional angina: the beneficial effects of calcium antagonists.

Coronary vasoconstriction may play a relevant role in the pathogenesis of exercise-induced myocardial ischemia, not only in patients with Prinzmetal's angina, but also in patients with chronic stable angina. In these patients the use of calcium antagonists, namely, dihydropyridine derivatives, may be beneficial. Hyperventilation is a simple and sensitive test to discriminate patients with effort angina who will improve their exercise capacity after administration of these drugs.

Angina Pectoris↗

PubMed1989

[The immunological profile of children with Down's syndrome].

In 1965 Benda demonstrated that bioptic and autoptic material of children with Down's syndrome showed hypoplasia of the thymus with poor histological differentiation between the cortex and medulla and impairment of Hassal's corpuscles which were also fewer than normal. In the seventies studies revealed the increased susceptibility to infections and higher incidence of leucosis in Down's syndrome patients as well as changes of immunologic defences (in particular cell mediated immunity). This study examines 35 children (16 boys and 19 girls) aged 6 months-20 years. Subjects were divided into a group of 18 cases in poor health with a history of recurrent infections and a group of 17 children in good health. Skin tests were performed by inoculating 0.1 ml of a solution formed by 1 ml physiological solution and 0.1 ml tetanus toxoid. Skin reaction was evaluated 48 hours later. Lymphocyte typing tests were performed with the rosette method and with monoclonal antibodies for T lymphocytes and with the determination of surface immunoglobulins for B lymphocytes. OKT4 (T helper), OKT8 (T suppressor) subsets assayed and the OKT4/OKT8 ratio was determined. Skin tests were negative in 3 cases (8.6%). The number of B lymphocytes was normal in all children. Total number of lymphocytes was decreased in 51.4% of cases. Two subjects had a reduction of OKT4 and 14 had an increased of OKT8 and 16 a significantly lower OKT4/OKT8 ratio. It is clear that skin tests were normal also in those children with low total lymphocyte values. The most closely related parameter to mobility was the OKT4/OKT8 ratio and the most distantly related on was the skin test. Only 3 cases had modifications of all 3 parameters together. Apart from the constant and complete immunological deficit described by many authors and which we cannot confirm the results of this study are in agreement with those of other authors.

Adolescent↗

PubMed1989

[Blood zinc in patients with Down's syndrome and its relations with their immune status].

Studies performed in the last decade have shown the importance of zinc in human physiology particularly in cell mediated immunity. Blood zinc values were assayed with the atomic absorption method using a Perkin/Elmer 2.380 spectrophotometer in 35 Down's syndrome subjects (DS) (16 boys and 19 girls aged 6 months 20 years) and in normal subjects in good health. The immunological picture was determined as previously described. Zinc values in normal subjects were in the range 92-128 micrograms/dl (mean value 107 +/- 10.46 micrograms/dl). The values are in the normal range. The range of blood zinc values of DS children was 60-138 micrograms/dl (mean value 92.22 +/- 19.76 micrograms/dl). Of the 35 subjects with DS, 16 had values of 60-84 micrograms/dl (mean 74.25 +/- 8.29 micrograms/dl) (table I), which are well below normal. Blood zinc values were not correlated to age and sex. A relationship was found with mortality. Out of 16 patients with low zinc values 10 (68.5%) were particularly susceptible to infections. These data were then related to results concerning the immunological status of a previous study. The only three negative skin tests were observed in subjects with low blood zinc. 62.5% of DS subjects with low blood zinc also had a complete lymphocyte deficit (table I) as compared to 42.1% of DS cases with normal zinc levels. Respectively 56.25% and 36.8% of DS cases with low blood zinc values had an abnormal and normal T helper/T suppressor ratio. Only 3 (8.57% of all cases and 18.75% of low blood zinc values) subjects had an alteration of all the parameter evaluated (including morbility).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

[Carnitine and Down's syndrome].

The present study revealed a degree of carnitine deficiency in a large percentage of Down's syndrome children. In fact below average carnitine levels were noted in 39.1% of the cases examined with severe deficiency in 4. On the basis of these data supplementary carnitine is recommended in cases of deficiency particularly in view of the value of carnitine in the prevention of cell aging.

Adolescent↗

PubMed1989

[Vitamin C in children with trisomy 21].

The present study revealed ascorbic acid deficiency in the blood of many children with Down's syndrome. It also revealed a fairly definite connection between Vitamin C deficiency and diet in these patients and a similar link between ascorbic acid deficiency and this incidence of infections. Where necessary the prescription of Vitamin C for the prevention and treatment of recurring infection is therefore recommended, bearing in mind the valuable antioxidant properties of ascorbic acid that can be exploited in combating cell deterioration.

Adolescent↗

PubMed1988

A study of the diterpene alkaloids of Aconitum napellus ssp. neomontanum during its onthogenetic cycle.

Qualitative and quantitative variations in the diterpene alkaloids content in the neomontanum subspecies of Aconitum napellus, growing near lake of Como, were studied throughout its complete onthogenetic cycle. Aconitine, N-deethylaconitine and two compounds with m.w. = 688 and m.w. = 629 have been detected in the various organs of plant almost at any time during the vegetative cycle.

Alkaloids↗

PubMed1988

A comparison of the bronchodilator effects of broxaterol and salbutamol.

In 12 adult patients with reversible bronchospasm (7 bronchial asthma and 5 chronic obstructive bronchitis) the bronchodilator activity and tolerability of 200 and 400 mcg of broxaterol hydrochloride (Z 1170) were compared to those of 200 mcg of salbutamol administered by metered-dose inhaler. A single dose of the drugs was compared in a double-blind balanced latin square cross-over design. FEV1, FVC, MMEF, MEF25, heart rate and blood pressure were measured just before and 7.5, 15, 30, 60, 120, 180 and 240 min after each treatment. At these times clinical evaluation was also carried out to ascertain the presence of side effects. In the doses employed, broxaterol and salbutamol caused significant increases over baseline FEV1, MMEF and MEF25 from 7.5 to 240 min and FVC from 7.5 to 120 min. The difference between the effects of the two doses of broxaterol on FVC, MMEF and MEF25 was significant at 15 min. No significant difference was observed in the activity curves of 400 mcg of broxaterol and salbutamol. The effects of salbutamol were significantly greater than those of 200 mcg of broxaterol on FEV1 at 7.5 and 15 min and on FVC, MMEF and MEF25 at 15 min. All three treatments were well tolerated. No significant changes were observed in heart rate or blood pressure and tremors were not reported in any patient.

Administration, Inhalation↗

PubMed1988