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C Martinelli

Publications and source records attributed to C Martinelli.

At least 19 recordsLinked to original sources
PubMed2006

The perineuronal glial tissue of spinal ganglia. Quantitative changes in the rabbit from youth to extremely advanced age.

The volumes of the nerve cell bodies and those of the enveloping satellite cell sheaths from spinal ganglia were determined by morphometric methods applied to electron micrographs in young, adult, old and very old rabbits. The mean volume of the nerve cell bodies increased progressively with age; this is probably related to the increase with age of the body size of the rabbits studied. The mean volume of the satellite cell sheaths did not differ significantly in young, adult and old animals, but was significantly smaller in very old animals. It is extremely unlikely that this marked reduction in the volume of the satellite cell sheath is the result of a pathological process. The mean value of the volume ratio between the satellite cell sheaths and the related nerve cell bodies did not differ significantly in young and adult animals, but was significantly smaller in old and very old animals. This ratio was particularly low in very old animals. Our analysis showed that in each age group the volume of the satellite cell sheath is linearly related to the volume of the related nerve cell body. This result suggests that in rabbit spinal ganglia the quantitative relations between glial and nervous tissue are tightly controlled throughout life. It is suggested that ganglionic neurons release signals to influence and control the volume of their associated glial tissue. Since satellite cells have important support roles for the neurons they surround, it is likely that the marked reduction in the volume of perineuronal sheaths in the extremely advanced age is accompanied by a reduction of those roles, with negative consequences for neuronal activity.

Aging↗
PubMed2006

A study of mitochondria in spinal ganglion neurons during life: quantitative changes from youth to extremely advanced age.

In view of the central role that mitochondria are thought to play in the ageing process, we investigated changes in mitochondria of spinal ganglion neurons in rabbits aged 1, 3.6, 6.7, and 8.8 years (the latter extremely old). Mitochondrial size increased significantly with age, while mitochondrial structure did not change. The total volume of mitochondria within the perikaryon did not change significantly during life. This indicates that in these neurons mitochondrial degradation was completely compensated by the production of new mitochondria even in the extremely advanced age. We also found that the mean volume of neuronal perikaryon increased markedly with age, so that the mean percentage of perikaryal volume occupied by mitochondria decreased significantly with a difference of about 33% between the youngest and the oldest animals. This decrease is only in very small part due to lipofuscin accumulation, so that the ratio of the total volume of mitochondria to the volume of functionally active cytoplasm decreased with age. The mitochondria of the neurons studied seem therefore unable to adapt their total volume to the volume of functionally active cytoplasm, that increases with age. This result is consistent with the observation that the neurons of old animals have a reduced ability to respond to high energy demands.

Aging↗
PubMed2005

Increase in number of the gap junctions between satellite neuroglial cells during lifetime: an ultrastructural study in rabbit spinal ganglia from youth to extremely advanced age.

This study investigated quantitative aspects of the gap junctions between satellite neuroglial cells that envelope the spinal ganglion neurons in rabbits aged 1 year (young), 3.6 years (adult), 6.7 years (old), and 8.8 years (very old). Both the total number of gap junctions present in 30,000 microm2 of surface area occupied by perineuronal satellite cells, and the density of these junctions increased throughout life, including the extremely advanced age. By contrast, the mean length of individual gap junctions did not change with age. Thus, the junctional system which provides morphological support for the metabolic cooperation between satellite cells in rabbit spinal ganglia becomes more extensive as the age of the animal increases. These results support the hypothesis that the gap junctions between perineuronal satellite cells are involved in the spatial buffering of extracellular K+ and in neuroprotection.

Aging↗
PubMed2005

Detection of Candida dubliniensis in oropharyngeal samples from human immunodeficiency virus infected and non-infected patients and in a yeast culture collection.

The incidence of Candida dubliniensis in oropharyngeal swabs of 132 human immunodeficiency virus (HIV)-positive and 89 HIV-negative patients was determined. The samples were plated onto CHROMagar Candida medium and 82 strains, presumptively identified as C. albicans or C. dubliniensis, were further investigated (temperature test, chlamydoconidia production, specific primer PCR). In addition, 487 collection strains (isolated from clinical samples and previously identified as C. albicans on the basis of a positive germ tube test) were screened in order to identify C. dubliniensis isolates. Two C. dubliniensis strains were isolated from two HIV-positive patients without oral candidiasis. Candida dubliniensis was not isolated from 89 HIV-negative patients nor was it identified among the collection strains.

Adolescent↗
PubMed2004

First case of Mycobacterium haemophilum infection in an AIDS patient in Italy.

Mycobacterium haemophilum, a strongly acid- and alcohol-fast bacillus belonging to the group of non-tuberculous mycobacteria was first described in 1978 as the cause of cutaneous ulcerating lesions in a woman with Hodgkin's disease. Infection due to M. haemophilum is rare but increasing in prevalence in immnunosuppressed subjects, particularly in patients with acquired immunodeficiency syndrome (AIDS) patients. The skin is the most common site of infection with erythematous or violaceous papules and/or nodules that are usually painless at first, but some elements develop into abscesses or ulcers that can become very painful. The incidence of M. haemophilum is unknown, but cases of infection have been reported in Australia, Canada, the United States, France, Israel, the United Kingdom and Taiwan; to date no cases have been reported in Italy, thus the case reported here is apparently the first one observed in our country.

AIDS-Related Opportunistic Infections↗
PubMed2004

Efficacy of the combination ampicillin plus ceftriaxone in the treatment of a case of enterococcal endocarditis due to Enterococcus faecalis highly resistant to gentamicin: efficacy of the "ex vivo" synergism method.

The case of a patient with highly gentamicin-resistant Enterococcus faecalis endocarditis treated with an ampicillin + ceftriaxone combination is described. We have designed a method to evaluate synergism between the antibacterial activity of patient's serum taken during a given antibiotic regimen (ampicillin) to which another antibiotic (ceftriaxone) is added in vitro. In this patient the two-drug combination was able to stop the bacteremia and prevent the infection of the prosthetic valve.

Aged↗
PubMed2004

Gap junctions between perineuronal satellite cells increase in number with age in rabbit spinal ganglia.

The gap junctions between perineuronal satellite cells were studied in the spinal ganglia of 12, 42, and 79-month-old rabbits. The mean number of gap junctions per 100 microm2 of surface of the section occupied by satellite cells was significantly greater in old rabbits than young adults. Since the mean length of individual gap junctions did not change with age, the increase in number of gap junctions cannot be due to fragmentation of pre-existing gap junctions but is very likely due to the formation of new gap junctions. The increase in number of gap junctions cannot be related to an increase in number of perineuronal satellite cells since the mean number of these cells is significantly smaller in aged rabbits than in young adults. It is suggested that the increase in number of gap junctions with age may enhance the suggested neuroprotective role of satellite cells towards ganglionic neurons. The present findings, together with previous observations, suggest that the gap junctions between perineuronal satellite cells are dynamic structures, able to adapt to varying neuronal demands and varying environmental conditions.

Aging↗
PubMed2003

Age-related quantitative changes in mitochondria of satellite cell sheaths enveloping spinal ganglion neurons in the rabbit.

We studied mitochondria in the satellite cell sheaths which envelope the spinal ganglion neurons of rabbits aged 12, 42, and 79 months. While the mean cytoplasmic volume of satellite cell sheaths did not change significantly with age, the mean percentage of cytoplasmic volume occupied by mitochondria decreased with age. This decrease is mainly due to a reduction in the total mitochondrial mass and only in minor part is a consequence of lipofuscin accumulation. Mitochondrial structure did not change, while mitochondrial size increased with age. Comparison between mitochondria in nerve cell bodies and those in satellite cell sheaths showed that: (1) the mean percentage of cytoplasmic volume occupied by mitochondria was greater in nerve cell bodies than satellite cell sheaths and the ratio between these two percentages remained constant with advancing age; (2) the total mitochondrial mass was much greater in nerve cell bodies than satellite cell sheaths and the ratio between these two values increased with age; (3) the extent of increase of mitochondrial size with age was similar in nerve cell bodies and satellite cell sheaths. The results of the present study suggest that: (1) the ability of satellite cell sheaths to produce energy decreases with age; (2) the decreased ability of sensory neurons in old animals to meet high energy demands may be partly due to the diminished contribution of their associated satellite cell sheaths.

Aging↗
PubMed2001

B vitamins induce an antinociceptive effect in the acetic acid and formaldehyde models of nociception in mice.

The effect of some B vitamins in chemical and thermal models of nociception in mice was investigated. The association thiamine/pyridoxine/cyanocobalamin (TPC, 20-200 mg/kg, i.p. or per os), thiamine, pyridoxine (50-200 mg/kg, i.p.) or riboflavin (3-100 mg/kg, i.p) induced an antinociceptive effect, not changed by naloxone (10 mg/kg, i.p.), in the acetic acid writhing model. Treatment for 7 days with thiamine/pyridoxine/cyanocobalamin (100 or 200 mg/kg, i.p.), thiamine (50 or 100 mg/kg) or pyridoxine (50 or 100 mg/kg) or acute treatment with riboflavin (6 or 12 mg/kg, i.p) inhibited the nociceptive response induced by formaldehyde. The B vitamins did not inhibit the nociceptive response in the hot-plate model. Both 7-day thiamine/pyridoxine/cyanocobalamin (100 mg/kg, i.p.) or acute riboflavin (25 or 50 mg/kg, i.p.) treatment partially reduced formaldehyde-induced hindpaw oedema. The B vitamins antinociceptive effect may involve inhibition of the synthesis and/or action of inflammatory mediators since it was not observed in the hot-plate model, was not reversed by naloxone, only the second phase of the formaldehyde-induced nociceptive response was inhibited, and formaldehyde-induced hindpaw oedema was reduced.

Acetic Acid↗
PubMed2001

Quantitative changes in mitochondria of spinal ganglion neurons in aged rabbits.

Within the context of our research on the age-related structural changes in spinal ganglia, we studied the mitochondria of the neuronal perikaryon in the spinal ganglia of 12-, 42-, and 79-month-old rabbits. Both the volume of the perikaryon and the total mitochondrial mass within the perikaryon increased significantly passing from young adult to old animals. Hence, there is no net loss of mitochondria in these neurons with age. Since, however, the volume of the perikaryon increased by more than 63% while the total mitochondrial mass within the perikaryon increased by only 18%, the mean percentage of perikaryal volume occupied by mitochondria decreased with age. This decrease is only in very minor part a consequence of lipofuscin accumulation, so that the ratio between the total mitochondrial mass and the functionally active volume of cytoplasm decreased with age. Possible causes of this decrease are discussed briefly. Moreover, while the mitochondrial structure did not change, mitochondrial size increased with age. Finally, in each of the three age groups both the mean percentage volume of mitochondria and the mean mitochondrial size were very similar in large light and in small dark neurons.

Age Factors↗
PubMed2001

Resolution of recurrent perianal condylomata acuminata by topical cidofovir in patients with HIV infection.

Anogenital condylomata acuminata are the most frequent clinical manifestation of genital human papillomavirus (HPV) infection. Association between human immunodeficiency virus (HIV) and HPV infections is frequent (range: 26-60% in males). Topical cidofovir (a nucleotide analogue antiviral drug active against a broad range of DNA viruses) is a potential treatment for anogenital warts in immunocompromised patients. We treated three HIV-infected patients with HPV perianal condylomas with topical 1% cidofovir in flexible collodion once a day for 2 weeks. The treatment resulted in complete clearance of the HPV lesions. The patients experienced mild transient erythema without any other side-effects. None of the patients relapsed during the 10-14-month follow-up period.

AIDS-Related Opportunistic Infections↗
PubMed2001

Evaluation of the Abbott AxSYM cytomegalovirus (CMV) immunoglobulin M (IgM) assay in conjunction with other CMV IgM tests and a CMV IgG avidity assay.

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was directly dependent on the sensitivity of the CMV IgM assay employed during the initial screen. The higher initial reactivity rate of the AxSYM CMV IgM assay was necessary in order to detect CMV IgM in specimens containing low-avidity CMV IgG antibodies, indicative of a primary CMV infection, which other CMV IgM assays (Behring, Vidas, Captia, and Eurogenetics) fail to detect in some cases. The use of the AxSYM CMV IgM assay, followed by an avidity test, should result in more accurate diagnosis of CMV infection in pregnant women.

Antibodies, Viral↗
PubMed2000

Incidence of adverse reactions in HIV patients treated with protease inhibitors: a cohort study. Coordinamento Italiano Studio Allergia e Infezione da HIV (CISAI) Group.

OBJECTIVE: To assess the probability that protease inhibitor (PI) therapy might be discontinued because of adverse events (AE) and to evaluate the incidence rate of adverse reactions during PI treatment. DESIGN: A prospective cohort, multicenter study on HIV-positive patients starting treatment with at least one PI. SETTING: Ten departments of infectious diseases in Northern Italy. PATIENTS: A total of 1207 patients who started PI therapy in September 1997 and were consecutively observed up to April 1999. MAIN OUTCOME MEASURES: Adverse reactions following initiation of PI therapy, and time to therapy discontinuation due to AE. RESULTS: During the study period, 35.9% patients presented adverse reactions of any grade, whereas 9.7% presented at least one serious AE. After 12 months of treatment, the percentage of patients who had interrupted treatment was 36% of ritonavir-treated patients, 14.2% of those treated with indinavir, 13.6% of ritonavir-saquinavir hard gel capsules (HGC)-treated patients, and 8.5% and 2.1%, respectively, for those treated with nelfinavir and saquinavir HGC. Women and patients with hepatitis experienced a significantly greater number of adverse events compared with other categories. Gastrointestinal events were more frequently observed in patients treated with either ritonavir alone or in combination with saquinavir HGC, as well as in patients receiving nelfinavir, although in this group serious events were rare. Here again, neurologic, metabolic, and hepatic toxicity occurred more frequently in ritonavir and ritonavir-saquinavir HGC treated patients. Allergic reactions were more often observed in patients receiving nelfinavir. Indinavir-treated patients presented the highest incidence of renal toxicity. CONCLUSION: Ritonavir is the drug associated with the largest number of reactions, which appear during the first few months of treatment. Saquinavir HGC and nelfinavir are the best tolerated drugs in a clinical setting.

Adult↗
PubMed1998

Age-related decrease in the overall extent of perikaryal projections in rabbit spinal ganglion neurons.

The overall extent of the perikaryal projections of sensory neurons from spinal ganglia of young adult and aged rabbits was estimated by a stereological method using the electron microscope. The extent of perikaryal projections was significantly smaller in the aged animals. This age-related decrease did not seem to depend on factors intrinsic to the neuron, but on the absence of a satellite cell covering over extensive portions of the nerve cell body surface. This decrease may influence the organization of the subplasmalemmal cytoskeleton, metabolic exchange between the nerve cell body and its environment and perhaps also neuronal metabolism.

Aging↗