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Biomedical subjects

G Neri

Publications and source records attributed to G Neri.

At least 199 records · Page 11Linked to original sources
PubMed1994

Gene for Simpson-Golabi-Behmel syndrome is linked to HPRT in Xq26 in two European families.

Linkage analysis was performed in 2 previously described European families segregating for the Simpson-Golabi-Behmel (SGB) syndrome. In both kindreds close linkage without recombination (zmax = 4.45 at theta = 0.00) was observed between the disease locus and the HPRT locus mapped in Xq26. These data are very similar to those (zmax = 7.5 at theta = 0.00) reported recently by others after studying a large Dutch-Canadian kindred with SGB syndrome. Compiled lod scores from the 3 families reach their maximum of 11.95 at recombination fraction of 0.00 with one lod unit support interval of 0.00-0.04.

Abnormalities, Multiple↗
PubMed1994

Effects of neuromedin U-8 on the secretory activity of the rat adrenal cortex: evidence for an indirect action requiring the presence of the zona medullaris.

The acute effect of increasing concentrations (from 10(-8) to 10(-6) M) of neuromedin U-8 (NMU-8) on steroid secretion of rat adrenal gland was investigated in vitro by high-pressure liquid chromatography. The production of the following steroids was measured: pregnenolone (PREG), progesterone (PROG), 11-deoxycorticosterone (DOC), corticosterone (B), 18-hydroxy-11-deoxycorticosterone (18OH-DOC), 18-hydroxycorticosterone (18OH-B) and aldosterone (ALDO). NMU-8 had no effects on either dispersed adrenocortical cells or fragments of adrenocortical autotransplants lacking medullary chromaffin cells. Conversely, NMU-8 exerted concentration-dependent secretagogue effects on adrenal slices, including both cortex and medulla. At all concentrations tested, NMU-8 increased the production of both PREG and total post-PREG steroids. The increase in total post-PREG steroid output induced by low concentrations of NMU-8 (10(-8) M) was due to similar rises in the production of non-18-hydroxylated steroids (PROG, DOC and B) and 18-hydroxylated hormones (18OH-DOC, 18OH-B and ALDO); conversely, that provoked by higher concentrations of the neuropeptide (10(-7) to 10(-6) M) was almost exclusively caused by the rise in the yield of 18-hydroxylated steroids. The stimulating effect of NMU-8 on PREG output was blocked by both alpha-helical-CRH and corticotropin-inhibiting peptide, which are competitive inhibitors of CRH and ACTH, respectively. The following conclusions have been drawn: (1) NMU-8 affects adrenal steroid secretion indirectly by acting on the medullary chromaffin cells, which in turn may paracrinally stimulate the cortical ones; (2) at all concentrations tested, NMU-8, by stimulating the intramedullary CRH/ACTH system, causes a net rise in the activity of the early rate-limiting step of steroidogenesis, with the consequent increase in the output of the entire spectrum of post-PREG steroids; and (3) at higher concentrations (over 10(-8) M), NMU-8 also elicits the release from chromaffin cells of a factor (not yet known) that specifically enhances 18-hydroxylase activity.

Adrenal Cortex↗
PubMed1994

Effects of cyclosporine-A on steroid secretion of dispersed rat adrenocortical cells.

The acute effect of cyclosporine-A (CSA), a potent immunosuppressive agent, on the secretory activity of dispersed rat adrenocortical cells was investigated. The production of the following steroid hormones was assayed by high performance liquid chromatography: pregnenolone (PREG), progesterone (PROG), 11-deoxycorticosterone (DOC), corticosterone (B), 18-hydroxy-11-deoxycorticosterone (18OH-DOC), 18-hydroxycorticosterone (18OH-B) and aldosterone (ALDO); B and ALDO outputs were also measured by radioimmunoassay. Low concentrations of CSA (0.1-0.2 mg/ml) enhanced basal, but not ACTH- or angiotensin-II (ANG-II) 10(-8) M-stimulated, secretions of PREG, non-18-hydroxylated steroids (PROG, DOC and B) and 18-hydroxylated steroids (18OH-DOC, 18OH-B and ALDO) of both zona glomerulosa (ZG) and zonae fasciculata and reticularis (ZF/ZR) cells. Middle concentrations of CSA (from 0.3 to 0.5 mg/ml) did not affect PREG yield, nor did they alter basal and ACTH-stimulated post-PREG output of both ZG and ZF/ZR cells; however, they elicited a marked decrease in ANG-II-enhanced production of 18-hydroxylated steroid by AG cells. Concentrations of CSA higher than 0.5 mg/ml strikingly reduced either basal and agonist-stimulated over-all steroidogenesis of both ZG and ZF/ZR cells. These findings suggest that CSA at low concentrations strongly stimulates the conversion of cholesterol to PREG (i.e. the rate-limiting step of steroidogenesis), while at middle concentrations it did not affect this early step, but specifically interferes with the intracellular events which transduce the stimulatory signal of ANG-II on the late steps of mineralocorticoid production (i.e. the conversion of B to ALDO). At higher concentrations, CSA probably exerts a cytotoxic effect.

Adrenal Cortex↗
PubMed1994

[Left cor triatriatum in a man over 60].

A case of cor triatriatum in a 66-year-old man is reported. The patient died of pneumonia; ante mortem diagnosis was made with both transthoracic and transesophageal echocardiography. Autopsy finding showed a very good correlation between anatomical and echocardiographic abnormalities. Cor triatriatum is amenable to surgical correction and echocardiography is extremely helpful in the diagnosis.

Age Factors↗
PubMed1994

[Endocarditis at risk of embolism. An indication for prophylactic surgical treatment?].

Two cases of embolic infective endocarditis on bicuspid aortic valve are described. The trans-thoracic and trans-esophageal echocardiographic aspect could leave easily suppose the possibility of embolism. The prophylactic surgical treatment, during the active phase, also if the indication is debated, could have probably avoided the serious consequences of embolism.

Adult↗
PubMed1994

One year experience of elderly hypertensive patients with isradipine therapy.

This is the first report of long-term use (one year) of isradipine, a new dihydropyridine calcium channel blocker, in the treatment of elderly patients with essential hypertension. Patients completing a three month, double-blind, multicentre study comparing isradipine to hydrochlorothiazide (HCTZ) were eligible to enroll in this open-label, continuation study. At initial baseline, patients were at least 60 years of age and had DBP from 95 mmHg to 120 mmHg. Patients were titrated when necessary every two weeks with isradipine, 5 mg to 15 mg once daily or 2.5 mg to 10 mg twice daily, to maintain sitting DBP < or = 90 mmHg. HCTZ, 12.5 mg to 50 mg once daily, could be added for better BP control. A total of 136 patients completed the one year, open-label phase. One hundred and fourteen patients (84%) received isradipine as monotherapy (mean dose, 9.7 mg/day); 22 received concomitant HCTZ therapy at one year. Reduction in DBP was significant and similar among all age groups and races (mean change of -19 mmHg). Reduction in SBP was similar among all age groups. Ninety-four per cent of those receiving isradipine monotherapy achieved BP control during the last four months of treatment. Twenty-six patients (16%) withdrew from the study: 11 (7%) had adverse reactions (one with headache, two with pedal oedema, eight with other problems); 11 (7%) had nondrug-related problems; and in four (2%), the drugs were ineffective. Based on these observations, isradipine is a well-tolerated, safe and effective agent for long-term BP control in elderly patients with essential hypertension.

Aged↗
PubMed1994

A new case of interstitial deletion of chromosome 3q, del(3q)(q13.12q21.3), with agenesis of the corpus callosum.

We describe a boy with an interstitial deletion of the proximal portion of chromosome 3q. Prominent physical characteristics were a dysmorphic face with apparent hypertelorism, signs of prenatal lymphedema, foot contractures and agenesis of the corpus callosum. The finding of corpus callosum agenesis in a previously reported patient with an overlapping deletion suggests an additional locus for this malformation.

Abnormalities, Multiple↗
PubMed1994

A somatic origin of homologous Robertsonian translocations and isochromosomes.

One t(14q14q), three t(15q15q), two t(21q21q), and two t(22q22q) nonmosaic, apparently balanced, de novo Robertsonian translocation cases were investigated with polymorphic markers to establish the origin of the translocated chromosomes. Four cases had results indicative of an isochromosome: one t(14q14q) case with mild mental retardation and maternal uniparental disomy (UPD) for chromosome 14, one t(15q15q) case with the Prader-Willi syndrome and UPD(15), a phenotypically normal carrier of t(22q22q) with maternal UPD(22), and a phenotypically normal t(21q21q) case of paternal UPD(21). All UPD cases showed complete homozygosity throughout the involved chromosome, which is supportive of a postmeiotic origin. In the remaining four cases, maternal and paternal inheritance of the involved chromosome was found, which unambiguously implies a somatic origin. One t(15q15q) female had a child with a ring chromosome 15, which was also of probable postmeiotic origin as recombination between grandparental haplotypes had occurred prior to ring formation. UPD might be expected to result from de novo Robertsonian translocations of meiotic origin; however, all de novo homologous translocation cases, so far reported, with UPD of chromosomes 14, 15, 21, or 22 have been isochromosomes. These data provide the first direct evidence that nonmosaic Robertsonian translocations, as well as isochromosomes, are commonly the result of a mitotic exchange.

Aneuploidy↗
PubMed1993

Split hand/split foot anomaly in a family segregating a balanced translocation with breakpoint on 7q22.1.

An apparently balanced translocation, t(2;7)(q21.1;q22.1) was detected in a female patient with bilateral split hand and right split foot. Split hand/split foot (SHSF) segregated as an autosomal dominant character with low penetrance in her family. The translocation was present in 6 of 13 additional relatives investigated, one of whom also had split hand on right. This observation provides further confirmation of the presence of a locus for SHSF on 7q and narrows the critical region to band 7q22.1. Defects caused by alterations of this chromosome region are variable and include manifestations of both syndromal and non-syndromal SHSF. Review of SHSF cases associated with chromosome 7 abnormalities showed a preferential involvement of the lower limbs and of the right side, suggesting the action of locally restricted developmental resistance mechanisms.

Chromosome Banding↗
PubMed1993

Costello syndrome: further clinical delineation, natural history, genetic definition, and nosology.

In 1977 Costello described two unrelated children with poor postnatal growth, mental retardation, curly hair, coarse face of similar appearance, and nasal papillomata, suggesting the existence of a previously undescribed syndrome of uncertain familial nature [Costello, Aust Paediatr J 13: 114-118, 1977]. The existence of this syndrome as a separate entity was substantiated several years later by two additional reports by Der Kaloustian et al. [Am J Med Genet 43:678-685, 1991] and Martin and Jones [Am J Med Genet 41:346-349, 1991]. More recently Borochowitz et al. [Am J Med Genet 43:678-685, 1992] described a new "multiple congenital anomalies/mental retardation syndrome with facio-cutaneous-skeletal involvement." Whether this condition should be considered separately from the Costello syndrome is currently a matter of debate. We present three cases, two of whom are sibs, who support the identity of the two syndromes. Our aim is to better redefine the diagnostic criteria, describe the natural history, and confirm the genetic cause of the Costello syndrome, whose pattern of inheritance is most likely autosomal recessive.

Abnormalities, Multiple↗
PubMed1993

Spastic paraplegia, epilepsy, and mental retardation in several members of a family: a novel genetic disorder.

We report on a family in which an association between spastic paraplegia and epilepsy has been observed. This disorder is an autosomal dominant trait with incomplete penetrance and variable expressivity. The onset was limited to the first four decades of life; the symptoms were typically those of progressive weakness and spasticity of lower limbs. Epilepsy was present in members of three of the four generations on whom we have information. The concomitance of spastic paraplegia and epilepsy in several members of the same family is unlikely to be fortuitous and probably represents the pleiotropic effect of a single mutant gene.

Adolescent↗
PubMed1993

Presymptomatic diagnosis of SMA III by genotype analysis.

Linkage analysis and prenatal prediction in families segregating autosomal recessive spinal muscular atrophy (SMA) has become feasible since the assignment of the locus responsible for type I-III SMA to region 5q12-q13.3. We have performed a segregation study of SMA in Italian families using molecular probes and highly informative PCR-based polymorphic markers. In one family, a 7-year-old boy affected with type III SMA and an 8-year-old apparently healthy brother had identical haplotypes. These findings prompted us to reexamine the apparently unaffected child. His neurological exam was normal. However, the electromyography (EMG) showed a pattern consistent with chronic SMA. To our knowledge this is the first example of presymptomatic diagnosis of SMA based on genotype analysis.

Base Sequence↗
PubMed1993

Trisomy 4 in acute myeloblastic and acute lymphoblastic leukemia.

We report three cases of trisomy 4 in acute leukemia. This alteration was detected as the sole cytogenetic abnormality in a case of FAB M4 leukemia; it occurred in association with 5q deletion in a case of M1, and concomitant with Ph chromosome and trisomy 17 in a case of L2 leukemia. The latter case represents the fourth report of trisomy 4 in acute lymphoblastic leukemia.

Adult↗
PubMed1993

A comparative study of the effect of atrial natriuretic peptide (ANP) on the secretory activity of rat adrenal cortex and angiotensin-II-responsive adrenocortical autotransplants.

Rat adrenocortical autotransplants regenerated from capsular-tissue fragments implanted in the musculus gracilis displayed an in-vitro basal gluco- and mineralocorticoid secretion qualitatively similar to that of adrenal quarters from control rats. Moreover, like adrenal quarters, they responded to angiotensin-II (Ang-II, 10(-8) M) by raising their yield of 18-hydroxylated steroids (18-hydroxy-11-deoxycorticosterone, 18-hydroxycorticosterone and aldosterone). ANP (10(-8) M), one of the main negative modulators of the zona-glomerulosa (ZG) mineralocorticoid secretion, totally blocked the ANG-II stimulating effect on adrenal quarters, but not that on adrenocortical autotransplants. Autoradiography showed that, in contrast with ZG cells of control rats, ZG-like cells of transplants did not significantly bind 125I-ANP. The hypothesis is discussed that ZG-like cells of regenerated adrenocortical nodules lack specific receptors for ANP.

Angiotensin II↗