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Biomedical subjects

G Riccio

Publications and source records attributed to G Riccio.

At least 19 recordsLinked to original sources
PubMed2001

The effects of a diode laser (810 nm) on pigmented guinea-pig skin.

Various types of lasers, such as the Q-switched ruby laser and the Alexandrite laser, cause selective damage to cutaneous pigmented cells and are currently used in the therapy of pigmented lesions. The aim of this study was to evaluate the effects of a diode laser at a wavelength of 810 nm on pigmented guinea-pig skin. The diode laser was supplied by OcuLight Iris Medical Instruments, Inc. and was used to deliver 0.15, 0.2, 0.3, 0.4, 0.5, 1 and 1.5 J/cm2 laser beams in micropulses of 100 micros. The study was carried out on albino and black-spotted guinea pigs (GP). After irradiation, punch biopsies were taken and analysed by light and electron microscopy. Albino animals developed just a few signs of cutaneous injury. This mostly consisted of spongiotic disarray, after the highest doses were administered (>1 J/cm2). In the black skin of spotted GPs alterations appeared at 0.15 J/cm2 and included melanosome damage and, at doses higher than 0.3 J/cm2, also melanocyte damage. These observations demonstrate that the diode laser at 810 nm selectively affects pigmented structures and that the cellular targets of diode laser radiation are the melanosomes. The diode laser specificity for melanin may provide a biological basis for the treatment of pigmented superficial cutaneous lesions.

Animals↗
PubMed2000

Cardiovascular effects of short-term growth hormone hypersecretion.

Many studies have shown that acromegaly has relevant effects on cardiovascular system, but few data are available regarding the effects of short-term acromegaly on heart morphology and function. These data would help to clarify the natural history of acromegalic disease and could provide new insight into the mechanisms of GH action on the human heart. Therefore, we studied by Doppler echocardiography a group of 10 young subjects strictly selected as having short-term (<5 yr) uncomplicated acromegaly. The results of this study have shown that shortterm acromegaly is characterized by significantly increased left ventricular mass (P<0.005), with normal relative wall thickness, associated with Doppler indices of diastolic function in the normal range. Furthermore, stroke index and cardiac index were significantly enhanced in the patient group (P<0.01 and P<0.001, respectively), whereas systemic vascular resistance was significantly reduced (P<0.001). In conclusion, our study shows that short-term acromegaly significantly affects the heart, but, at variance with long-term disease, it is characterized by increased left ventricular mass, with eccentric remodeling and normal diastolic function. Moreover, short-term acromegaly induces a high cardiac output state with reduction of systemic vascular resistance.

Acromegaly↗
PubMed2000

[Myocardial metabolism of calcium in heart failure: from physiology to new therapeutic perspectives].

Development of heart failure is associated with an impairment of intracellular calcium handling. The precise mechanisms involved are still obscure. When membrane depolarization occurs, a small amount of extracellular calcium enters the intracellular milieu through the L-type channels. Such "trigger" calcium acts on specific receptors of the sarcoplasmic reticulum, that, in turn, according to the so-called calcium entry-calcium release mechanism, allows the release of a larger amount of calcium from the sarcoplasmic reticulum. Removal of calcium from the cytosol is the key event of the diastolic phase. Calcium removal from cytosol occurs through specific membrane pumps. Recent therapeutic approaches involving gene targeting of calcium pumps have yielded promising results. Specifically, increased levels of SERCA 2 in the myocardium have shown to enhance cardiac contractility under normal circumstances and in experimental heart failure. Future research is needed to confirm these findings in human heart failure.

Calcium↗
PubMed1999

Prevalence of HNPCC in a series of consecutive patients on the first endoscopic diagnosis of colorectal cancer: a multicenter study. The Italian Collaborative Group.

BACKGROUND AND STUDY AIMS: It is difficult to measure the prevalence of hereditary non-polyposis colorectal cancer (HNPCC) in geographical areas that do not have tumor registers, as is the case in the present study, and it was therefore decided to assess the prevalence in Italy using different methods. PATIENTS AND METHODS: The pedigree was established for 485 of 501 colorectal cancer patients diagnosed with colorectal carcinomas. Patients were included consecutively in 13 gastroenterology centers; they had not taken part in prevention examinations. Information was collected regarding the neoplastic pathology observed in the families, confirmed in 90% of cases among 3515 first-degree relatives and in 79.5% of cases among 7068 second-degree relatives. RESULTS: In the 3515 first-degree relatives (1002 parents, 1560 siblings and 953 children), 61 colorectal carcinomas, 29 carcinomas in the digestive tract outside the colon, and 99 carcinomas in other locations were reported. Only five of the 485 patients (1%) satisfied the Amsterdam criteria (three cancers, two of which were in first-degree relatives in different generations and one in a relative younger than 50). When broadening the criteria that we are proposing (satisfying only two of the three Amsterdam criteria), the prevalence would increase to 3% (15 cases). CONCLUSIONS: Modifying the criteria makes it easier to identify new mutations or confirm the existence of those already known, as well as allowing preventative treatment in relatives who are apparently healthy.

Adenocarcinoma, Mucinous↗
PubMed1999

[Effects of chronic subclinical hyperthyroidism from levothyroxine on cardiac morphology and function].

BACKGROUND: Thyroid hormones greatly affect the cardiovascular system. Although the effects of overt hyperthyroidism on the cardiovascular system have been diffusely studied, only in the last years the effects of subclinical hyperthyroidism on the heart have been investigated. Subclinical hyperthyroidism is a symptomatic or asymptomatic condition with an absent response of thyrotropin (TSH) to thyrotropin-releasing hormone in the presence of normal serum levels of thyroid hormones for the general population, though supraoptimal for the individual. The more frequent causes of endogenous subclinical hyperthyroidism are multinodular goiter, toxic, adenoma and Graves's disease, whereas the exogenous causes are induced by levothyroxine (LT4) therapy used to suppress TSH in patients with nontoxic goiter and differentiated thyroid cancer. This paper reports our experience derived from the study of 60 patients with subclinical hyperthyroidism due to TSH-suppressive therapy with LT4 compared to normal subjects. METHODS: Patients (9 males and 51 females, mean age 39 +/- 10 years) were studied by complete Doppler echocardiography, standard and 24 hour ECG Holter monitoring, exercise test with cycloergometer, and radionuclide ventriculography at rest and during fixed workload (75 W). RESULTS: Holter monitoring showed a significant increase in mean 24 hour heart rate (80 +/- 10 vs 70 +/- 9 b/min, p < 0.001) and supraventricular arrhythmias (42 vs 12 patients, p < 0.003). Echocardiography showed an increase in left ventricular mass index (94 +/- 13 vs 80 +/- 18 g/m2, p < 0.001) due to increased septal and posterior wall thickness. At rest, echocardiographic indices of systolic function (fractional shortening and mean corrected velocity of circumferential fiber shortening) were higher in patients than in controls (fractional shortening 40 +/- 6 vs 34 +/- 4%, p < 0.001; mean corrected velocity of circumferential fiber shortening 1.23 +/- 0.17 vs 1.05 +/- 0.14 circ/s, p < 0.001), while the Doppler indices of diastolic function were significantly impaired as documented by the reduced E/A ratio (1.18 +/- 0.3 vs 1.8 +/- 0.5, p < 0.001) and the prolonged isovolumic relaxation time (94 +/- 13 vs 78 +/- 12 ms, p < 0.001). Exercise tolerance was also significantly impaired in patients with subclinical hyperthyroidism: maximal exercise time (6.4 +/- 0.7 vs 9.4 +/- 1.4 min, p < 0.001) and peak workload (81 +/- 11 vs 121 +/- 17 W, p < 0.001) were significantly reduced and radionuclide ventriculography showed a decrease in ejection fraction during exercise (from 62 +/- 7 to 53 +/- 8%, p < 0.002). CONCLUSIONS: Persistent subclinical hyperthyroidism by TSH-suppressive doses of LT4 significantly affects heart morphology and function. Thus, we suggest that a complete suppression of TSH must be recommended only in patients with differentiated thyroid cancer, while in patients with begin thyroid disease it could be sufficient to maintain subnormal TSH levels.

Adult↗
PubMed1998

Phaeomelanin versus eumelanin as a chemical indicator of ultraviolet sensitivity in fair-skinned subjects at high risk for melanoma: a pilot study.

It is now generally agreed that solar exposure is a major external factor in the causation of cutaneous melanoma in light skinned populations with red hair and a marked susceptibility to the acute effects of ultraviolet (UV) radiation. In the present study, we investigated the existence of a possible relationship between hair melanin composition and minimal erythema dose (MED), as an indicator of UV sensitivity, in a group of 15 healthy red-haired subjects aged 20-46 years. In spite of comparable skin and hair colour, marked variations were observed in the MED values as well as in the hair melanin composition. Phaeomelanin levels varied in the range 0.026-0.53% w/w and were generally comparable to or higher than eumelanin levels (0.042-0.17% w/w). No significant relationship was found between MED values and phaeomelanin, eumelanin or total melanin (eumelanin plus phaeomelanin) content. Notably, however, a gross positive correlation was found between the eumelanin/phaeomelanin ratio and the MED values. These results would suggest that a high UV sensitivity is associated with high phaeomelanin and low eumelanin levels, and point to the eumelanin/phaeomelanin ratio as a novel chemical parameter that could be used for predicting individuals at high risk for skin cancer and melanoma.

Adult↗
PubMed1998

The acute effect of smoking on cutaneous microcirculation blood flow in habitual smokers and nonsmokers.

BACKGROUND: Smoking is known to be a primary cause of chronic harmful effects on the vascular system. It also induces some acute effects on the coronary circulation and on the ophthalmic artery. OBJECTIVE: The aim of our study was to assess the effect of smoking a single cigarette on cutaneous blood flow in habitual smokers as well as in nonsmokers. METHODS: A laser Doppler flowmeter was used to perform measurements of cutaneous microcirculation. Flowmetric data were recorded (i) before smoking, (ii) inhaling from an unlighted cigarette, (iii) during cigarette smoking, (iv) 2 and (v) 5 min after smoking. RESULTS: We could show that smoking a single cigarette acts on the cutaneous microcirculation reducing blood flow in both groups of subjects (38.1% reduction in smokers and 28.1% reduction in nonsmokers; p <0.01). Interestingly, the recovery phase is faster in nonsmoker subjects than in smoker ones; in fact, the recovery is complete 2 and 5 min after cigarette smoking in nonsmokers and in smokers, respectively. CONCLUSION: Smoking a single cigarette decreases the cutaneous blood flow in habitual smoker as well as in nonsmoker subjects. Moreover, the slower recovery phase of smokers suggests that their microcirculation become inured to smoke.

Adult↗
PubMed1997

Thirty hours' evaluation of UVB-induced erythema by chromometry and microflowmetry.

BACKGROUND: Individual UVB photosensitivity is usually investigated by determining the minimal erythemal dose (MED). Nevertheless, factors such as room light intensity and subjective experience of the observer can influence the erythema perception and, therefore, the MED assessment. OBJECTIVE: To evaluate the relationship between the clinical and the chromometric and microflowmetric analyses of the UVB-induced erythema in 2 healthy volunteers. METHODS: A bank of 6 fluorescent mercury vapor tubes (Philips TL 12/20 W) was utilized as a source of UVB light. Three skin areas (4 cm2), from the dorsal region of each subject, were irradiated with 3 different UVB doses corresponding to: (1) MED; (2) 0.7 MED, and (3) 1.3 MED. RESULTS: (1) both microflowmetric and chromometric parameters reached a maximum peak 10-12 h after irradiation and maintained high values also 30 h after irradiation; (2) both microflowmetric and chromometric values were directly related to the UVB doses; (3) in some cases the microflowmetric values started to increase when the chromatic changes were still undetectable. CONCLUSION: These preliminary data confirm that the visual determination of MED performed 24 h after irradiation is a correct procedure. Nevertheless, the microflowmetric may precede the chromatic changes suggesting that vasodilatation follows irradiation without a latent period.

Adult↗
PubMed1997

[Bacterial infections in HIV patients].

AIM OF THE STUDY AND METHODS: Retrospective analysis of bacterial infections occurring in 400 admissions of HIV-positive patients in the Infectious Diseases Unit of the Azienda Ospedale Santa Corona, Pietra Ligure (SV), from January 1994 to September 1996. RESULTS: 56 episodes were documented (14% of admissions): 24 (43%) hospital acquired (11 sepsis, 5 pneumonias, 6 urinary-tract infections, 1 infection of a prosthetic device) and 32 (57%) community-acquired (9 sepsis, 13 pneumonias [6 with bacteremia] 9 urinary-tract infections, 1 endocarditis). At time of diagnosis mean absolute CD4-lymphocyte count was 106/cmm (95% Cl 62-150) and mean neutrophil count was 4.690/cmm (95% Cl 3.466-5.914); 11 patients had a central venous catheter, 9 a vesical catheter and 7 severe skin lesions. Methicillin-resistant S. aureus (11/24, 46%) and Pseudomonas (8/24, 33%) were the most frequently isolated pathogens in hospital infections, while the majority of community acquired episodes were due to S. pneumoniae (10/32, 31%). In six episodes (11%) the patient died because of the bacterial infection. CONCLUSIONS: Bacterial infections are quite frequent in this cohort of HIV-infected patients. Methicillin-resistant S. aureus and Pseudomonas represented the major cause of hospital acquired infections, while S. pneumoniae represented the major cause of community acquired episodes.

English Abstract↗
PubMed1994

A simple cryo-technique for the treatment of cutaneous soft fibromas.

OBJECTIVE: We propose a simple cryo-technique for the treatment of cutaneous soft fibromas. METHODS: This method, useful for fibromas larger than 4-5 mm in diameter, allows the freezing of the only soft fibroma without affecting the surrounding skin. RESULTS: The technique shows the following advantages: it is simple to perform, it avoids local anesthesia, and it can be used in pacemaker holders. CONCLUSION: The cosmetic results are very good.

Cryosurgery↗
PubMed1990

[Churg-Strauss syndrome: is it a rare disease?].

We describe four patients with Churg-Strauss syndrome admitted to the hospital in 1988. Some clinical and histological features of particular relief are present in these cases. All patients had been treated with corticosteroids and they are now in remission. Our work suggests that Churg-Strauss syndrome is not a rare disease and that an early diagnosis and appropriate therapy may influence favourably at least long term survival.

Adult↗
PubMed1989

[Gigantic fibroadenoma of the breast in an adolescent. Description of a clinical case].

A case of giant fibroadenoma in a girl of 14 is reported. This case emerged from an examination of about 380 patients observed at the Senology Clinic of the S. Maria di Loreto Hospital (USL 44) in the last 3 years. A statistical contribution is made to the study of breast pathologies in pubertal age and stress is laid on the importance of mass screening among adolescents.

Adolescent↗