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Biomedical subjects

C Romano

Publications and source records attributed to C Romano.

At least 181 records · Page 10Linked to original sources

Growth factor upregulation of a phosphoinositide-coupled metabotropic glutamate receptor in cortical astrocytes.

CNS function depends on a capacity for plasticity during development, following injury, and in response to changing environmental conditions. Functional alterations in signal transduction pathways and in neurotransmitter receptor expression are possible mechanisms for the expression of such plasticity. In the present report, we demonstrate that exposure of astrocytes to specific growth factors alters both the functional activity and the protein levels of a specific glutamate receptor. Exposure of astrocytes to basic fibroblast growth factor, epidermal growth factor, or transforming growth factor-alpha produced marked increases in the ability of metabotropic glutamate receptor (mGluR) agonists to stimulate phosphoinositide hydrolysis. Using Western immunoblotting, we demonstrate that an increase in the levels of one of the phosphoinositide-coupled mGluR subtypes, mGluR5, accompanies the increased ability of mGluR agonists to stimulate phosphoinositide hydrolysis. In contrast, another phosphoinositide-coupled subtype of this receptor family, mGluR1 alpha, was not present at detectable levels in these cultures. The enhanced stimulation of phosphoinositide hydrolysis showed little sensitivity to pertussis toxin, and appeared to be selective to mGluR agonists, as there was not a similar increase in the ability of norepinephrine or carbachol to stimulate phosphoinositide hydrolysis. These findings demonstrate that expression of mGluRs in astrocytes is plastic, and indicate a novel pathway through which specific growth factors may selectively modulate neurotransmitter action.

Animals↗

[Nasal patency patterns observed during working hours in a group of technicians habitually exposed to formaldehyde].

Formaldehyde is a substance which is widely used in several work fields, including many medical and biological sectors. It appears that formaldehyde exposure may cause bronchial asthma. Little information is available, however, with regard to upper aereal tracts. The nose is a target organ of major importance for a large range of professional and extra-professional environmental pollutants. In particular, cases of professional rhinitis brought about by exposure to disinfectants have been reported in Literature. In the light of general knowledge related to the close correlation between upper and lower airways, and to the lack of information concerning the effects of short-term formaldehyde exposure on the upper aereal tract, the Authors decided that investigation of such exposure might prove interesting as well as worthwhile. A group of fifteen technicians who work in three different pathology departments and who had been exposed to formaldehyde for at least one year were studied. The purpose of the study was to assess possible alteration in nasal resistances at the end of a normal work shift. The subjects under study were observed according to a procedure which included several clinical, allergological, serological and functional evaluations carried out on specific days of the week. A control group, consisting of eight asymptomatic, non-atopic subjects who had never been exposed to inhalation of irritants was also monitored in the same way. Conclusions were drawn after considering some important variables such as exposure time, possible anatomical alterations of the nose, the presence of respiratory allergies and smoking habits. It was apparent that professional formaldehyde exposure typical of that experienced by technicians working in pathology departments induced a short-term irritant effect on the upper aereal tract, which, even though subclinical, is revealed by a statistically significant increase in nasal resistance. This effect seems to be favoured (at statistically not significant levels) by atopy, cigarette smoking and anatomical alterations of the nose. Our data seem to exclude a chronic cumulative effect of formaldehyde exposure.

Adult↗

Increasing incidence of childhood celiac disease in Sicily: results of a multicenter study.

By screening the patient list of four Sicilian centers of gastroenterology and those with gluten-free product consumption, 1074 patients (607 females and 467 males) with celiac disease, diagnosed between 1975 and 1989, were identified. A maximum cumulative incidence rate by birth cohort was reached in 1986 (1.65/1000). When the incidence rate was adjusted for the years of follow-up, the actual standardized rate was 3 cases per 1000 live births. Growth failure and chronic diarrhea were the most common symptoms, but a diminishing trend for chronic diarrhea was observed when symptoms were distributed by year of diagnosis. Even though 61.1% of all cases were diagnosed within six months from the onset of symptoms, mean age at diagnosis showed an increasing trend, from less than two years to approximately four years of age. The results of our study showed an increasing incidence of celiac disease due to diagnosis of less typical cases at an older age and also to a steady increase in the rate of diagnosis of cases with a classic clinical picture.

Celiac Disease↗

Prolactin responsiveness to peptide histidine methionine-27 in normal subjects and hyperprolactinemic patients.

In order to verify whether synthetic peptide histidine methionine (PHM-27) is able to induce serum prolactin (PRL) rise in normal subjects and to investigate its effect on PRL secretion in hyperprolactinemic conditions, PHM-27 (100 micrograms i.v. over 60 min at a rate of 3.3 micrograms/min) was given to 6 normal subjects and 11 hyperprolactinemic women, and serum PRL levels were measured before and at intervals up to 120 min after beginning the infusion. On a separate occasion, a saline infusion was administered to all these subjects as a control test. In normal subjects, PHM-27 caused PRL to increase from 7.8 +/- 1.4 micrograms/l (mean +/- SE) to 13 +/- 2.1 micrograms/l (p < 0.05), the peak occurring at 30 min, whereas it did not significantly modify serum PRL levels in 11 patients with prolactin-secreting adenomas. We also observed a significant difference of serum PRL pattern during PHM infusion when compared to saline in normal subjects. In contrast, in hyperprolactinemic states, PRL curves were similar in both tests. Continuous infusion of PHM-27 was very well tolerated and caused no important adverse events. These data suggest that PHM, like vasoactive intestinal peptide, can participate in the regulation of PRL release under physiological conditions and that the unsignificant PRL increase in PRL-secreting tumors may reflect abnormalities of the PRL secretion mechanism in these pathological states.

Adolescent↗

Incidence of type I diabetes in the Liguria Region, Italy. Results of a prospective study in a 0- to 14-year age-group.

OBJECTIVE: To assess updated incidence of insulin-dependent diabetes mellitus (IDDM) in 0- to 14-year-old children in Liguria, a northwest region of Italy. RESEARCH DESIGN AND METHODS: Incident cases were recorded prospectively from 1987 to 1991. Incidence rates (IRs) were directly standardized on the basis of the 1990 world population. The independent effect of age, sex, residence, and calendar year was estimated with a Poisson regression model. The degree of ascertainment was calculated in accordance with the capture/recapture method. RESULTS: During 5 full calendar years, 117 new cases of IDDM in children were diagnosed in Liguria. The standardized IR over the 5-year period was 11.72 cases.100,000(-1).year-1. The sex-specific IR among males and females was 11.45 and 12.01, respectively. The age-specific IR was higher in the 5-9 age-group. CONCLUSIONS: The IR of IDDM in Liguria is among the highest in southern Europe and approaches that of northern European countries. In particular, it is much higher than those reported in the surrounding Italian regions, except for Sardinia. Therefore, the geographical distribution of IDDM does not seem to reflect the simple north-south gradient reported in several previous studies.

Adolescent↗

[Nerve-sparing retroperitoneal lymph node dissection in patients with non-seminomatous testicular tumors at clinical stage 1].

Retroperitoneal lymph node dissection (RPLND) for low stage testicular cancer involves a low rate of dry ejaculation. The nerve-sparing technique avoids the damage of sympathetic fibers. 7 cases of non seminomatous testicular cancer have been treated by the Author. Through midline incision and intestinal derotation the vascular plane and the sympathetic fiber are identified before starting lymph node dissection. All the patients report physiological ejaculation; the post-operative follow-up is still short but at the present all patients are tumor free. In low stage testicular cancer nerve-sparing lymphadenectomy preserve physiological ejaculation and reducing surgical morbidity as well.

Erectile Dysfunction↗

A clinical follow-up of British patients with FG syndrome.

The FG syndrome is an X-linked recessive mental retardation syndrome. Ten patients are reviewed with special emphasis on the natural history of the intellectual development, constipation, and the prognosis for growth and behaviour. Six out of 10 patients are still macrocephalic, and there is no evidence for a specific growth pattern with respect to height. The degree of mental retardation is is usually severe. The behaviour is characteristically friendly, sociable and over-talkative, with periodic aggression. Six patients have seizures. A characteristic progression seems to occur from congenital hypotonia with joint hyperlaxity at birth, to joint contractures with apparent spasticity and unsteady gait later in life. The constipation was a temporary problem in five cases. The cowlick and the fetal pads persist and are important, but not specific, for the diagnosis.

Abnormalities, Multiple↗

The emerging role of magnetic resonance imaging in rheumatology.

The role of magnetic resonance imaging (MRI) in imaging the central nervous system and in orthopedic radiology is now well accepted. Numerous applications of this technique also exist in the field of rheumatology, and it is anticipated that MRI will play an important part in the evaluation of treatments for the arthritides. In addition, MRI allows noninvasive investigation of other rheumatologic problems, such as avascular necrosis, tendon disorders and myopathy. This review outlines the current applications of MRI in rheumatologic practice.

Humans↗

Presence of telomeric and subtelomeric sequences at the fusion points of ring chromosomes indicates that the ring syndrome is caused by ring instability.

In situ hybridization of a telomeric (TTA-GGG)n sequence to metaphases from three cases of ring chromosome, involving respectively chromosomes 4, 16, and 20, showed the presence of the cognate sequences in all three rings. To investigate whether these ring chromosomes originated by telomere-telomere fusion, we determined, by in situ hybridization, whether telomere-associated sequences and/or specific distal sequences were still present in the ring chromosomes. The finding that these sequences were preserved in all the ring chromosomes strongly indicates that they originated by telomere-telomere fusion. All three subjects carrying the ring chromosomes are affected by the so-called ring syndrome, with failure to thrive, minor dysmorphic signs and no major anomalies. The r(4) patient has the ring in mosaic form with a normal cell line and has normal intelligence. The r(16) and the r(20) patients have moderate mental retardation and suffer from seizures. We conclude that the ring syndrome, even in its more severe manifestation, is caused by ring chromosome instability.

Adolescent↗

Assessment of pediatric near-drowning victims: is there a role for cranial CT?

Previous studies have suggested that CT examinations of the brain in children soon after near-drowning incidents are not helpful in predicting clinical outcome and are not necessary. The clinical and CT findings of 19 pediatric near-drowning victims were reviewed for correlation with clinical and neurologic outcome. As expected, a normal initial CT scan was poorly predictive of outcome, whereas an abnormal CT scan in the initial 36 h following an immersion incident was associated with a dismal prognosis. Three children with abnormal initial CT examinations were identified and all died within 3 days of admission. A CT scan performed in the immediate near-drowning period, therefore, may be helpful in identifying some patients who have sustained severe neurologic injury.

Adolescent↗

The prediction of recommended energy expenditure for an 8 h work-day using an air-purifying respirator.

Thirty railway workers executed maximal, or near maximal, stress tests with and without the use of a half mask air-purifying respirator (Spasciani 85 A1 P1) fitted with two combined filters for simultaneous protection from organic vapours and particulate matter. The pressure-flow characteristics of inspiratory and expiratory resistance at airflows in the range 0-90 l.min-1 were established by a continuous flow method on one test mask. Significant differences were found by paired t-test between the two exercises (with and without use of mask), showing reduced values with use of the mask, for breath frequency, ventilation rate, oxygen uptake, carbon dioxide production, maximal oxygen uptake, percentage of maximal voluntary ventilation used at the maximal exercise ventilation. No significant differences were found for tidal volume, respiratory quotient, heart rate, systolic blood pressure, oxygen uptake at anaerobic threshold, and duration of exercise. The predicted energy expenditure recommended for an 8 h work shift, corresponding to 40% of maximal oxygen uptake, is found to be reduced working with respirator and is significantly different from that observed during stress test without mask. The average ventilation rate at this workload is below 25 l.min-1, with predicted inspiratory mouth pressure equal to, or less than, 20 mm H2O. This maximal inspiratory mouth pressure is proposed as a safety limit for prolonged work using a respirator, with a recommended energy expenditure close to 40% of maximal oxygen uptake.

Adult↗

An intronic deletion leading to skipping of exon 21 of COL1A2 in a boy with mild osteogenesis imperfecta.

A mild form of osteogenesis imperfecta was diagnosed in a 5-year-old boy with short stature, osteoporosis, blueish sclerae, dentinogenesis imperfecta, hyperextensible joints and bruisable skin. His skin fibroblasts synthesized both normal and shortened pro-alpha 2(I) collagen chains. Procollagen I molecules containing the shortened pro-alpha 2 chains were unstable and thus virtually excluded from secretion at 37 degrees C. Secretion was only partially restored at 30 degrees C. Cyanogen bromide mapping confined the defect to peptide alpha 2(I)CB4. PCR amplification of cDNA showed that the 108 nucleotides corresponding to exon 21 (coding for residues 274 to 309 of the helical domain) were missing in about half of the COL1A2 mRNA. Genomic DNA analysis showed that both exons 21 of COL1A2 were intact, but nucleotides +2 to +40 in intron 21 were deleted on one allele. The intronic deletion altered the conserved nucleotides at position +2 and +5 of the splicing donor site and apparently caused skipping of exon 21 during mRNA splicing. The mild phenotype associated with this COL1A2 mutation may be explained by very poor secretion of the structurally defective procollagen I molecules, which minimizes their deleterious effects on extracellular matrix formation.

Alleles↗

Neuroprotectants in Honghua: glucose attenuates retinal ischemic damage.

PURPOSE: This study examined the neuroprotective properties of Honghua, an extract of safflower used as an herbal medicine in China, in several experimental models of retinal ischemia. METHODS: Honghua and other agents were tested (1) in the ex vivo chick embryo retina assay (CER) for anti-excitotoxin efficacy and against simulated ischemia (30 min glucose/oxygen deprivation); and (2) in the in vivo adult rat retina dye-photothrombosis assay. Active components of Honghua were purified by conventional chromatographic techniques. RESULTS: In the CER, Honghua protected against excitotoxicity of glutamate, N-methyl-D-aspartate, kainate, and quisqualate, and against neuronal degeneration caused by simulated ischemia. Honghua more potently protected against simulated ischemia than against the agonists. In the in vivo adult rat retina, ischemic damage was reduced greatly by intravitreal injection of Honghua. An approximately 100-fold purification of an active principle was achieved chromatographically. The purest fractions were rich in glucose, so the effects of glucose in the ischemia models were determined. Many neuroprotective effects of Honghua were mimicked by pure solutions of equivalent glucose concentration. Glucose (> 3.2 mmol/l) in the CER-ischemia assay provided protection. Glucose did not protect against the lesions induced by direct application of the excitotoxic agonists. Intravitreal injection of glucose provided highly significant neuroprotection in the adult rat retina dye-photothrombosis model. CONCLUSIONS: These results suggest that retinal excitotoxic damage in vivo can occur secondary to depletion of cellular energy reserves, and therefore may be prevented by simple procedures that maintain the availability of energy sources.

Animals↗