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Biomedical subjects

L Ghisoni

Publications and source records attributed to L Ghisoni.

14 recordsLinked to original sources
PubMed2003

[Brain vulnerability and its modulation].

Clinical and experimental studies revealed that the injured brain is highly vulnerable to a subsequent insult. Surfery of the literature pertinent to clinical and experimental traumatic brain injury (TBI) is made. Increased vulnerability of the traumatically injured brain to an additional sub lethal ischemic, hypoxic, excitotoxic, or mechanical insult has been clearly demonstrated. Compared to traumatic brain injury alone, the double insult paradigm dramatically increases the brain damage. Brain vulnerability following TBI can be explained by a reduced ability to compensate for a reduction of cerebral blood flow (CBF) and oxygen (O(2)) delivery to the brain or inability to meet an increased metabolic demand. In addition, there is a specific increased sensitivity to delayed insults induced by the first injury. Potential mechanisms of the increased sensitivity to a second insult might be related to post-traumatic gene expression alterations leading to changes in neurotransmitters release, density of receptors and reduced thresholds for activation of pathways leading to delayed cell death. The brain is vulnerable to repetitive injuries. Derangements of compensatory mechanisms are responsible, in part, for this vulnerability. Additional work is needed to better understand the molecular pathways leading to secondary damage and to find novel therapeutic strategies to modulate the brain response to TBI.

Brain Chemistry↗
PubMed1996

Soluble transferrin receptor in the study of fetal erythropoietic activity.

In order to evaluate fetal erythropoiesis we measured red blood cells, hemoglobin, hematocrit, serum transferrin receptor (sTfR), and iron status parameters in fetuses undergoing percutaneous umbilical blood sampling, and in normal newborns at term. We found high levels of sTfR in fetuses and newborns as compared with normal adults (3,149 +/- 181 vs. 1,881 +/- 137 ng/ml, P < 0.00001). Concentrations of sTfR correlate with gestational age and red blood cell numbers (r = 0.441, P < 0.001; r = 0.366, P = 0.06). sTfR concentrations do not show correlation with iron status parameters. The increased sTfR concentration is consistent with the fact that fetal life is characterized by cell proliferation and tissue growth. sTfR concentration correlates with gestational age and numbers of red blood cells, and can therefore be considered a good indicator of fetal erythropoiesis. It is conceivable that, during intrauterine life, sTfR expression is independent from iron status. sTfR determination will help in reaching a better understanding of some aspects of fetal physiology, and will help elucidate the physiopathology of fetal hematological diseases.

Erythrocyte Count↗
PubMed1995

Genetic amniocentesis in biamniotic twin pregnancies by a single transabdominal insertion of the needle.

We present a technique to aspirate amniotic fluid from both sacs in biamniotic twin pregnancies using a single abdominal insertion with a spinal needle. It was successful in 48 out of 55 cases of biamniotic twin pregnancies referred to our perinatal unit between 1985 and 1994. The single insertion technique was used when the inter-amniotic membrane was clearly evident and two separate free amniotic fluid pools could be reached by the operator with a single puncture. An adequate amount of amniotic fluid was sampled from both sacs to make a cytogenetic diagnosis in all cases. There were four fetuses with trisomy 21 in three twin pregnancies. In two cases, only one twin was affected whilst the co-twin was normal, so that a selective feticide was performed. No miscarriages due to genetic amniocentesis were reported. After 1990, all genetic amniocenteses in biamniotic twin pregnancies (except for one case due to late booking) were performed between 14 and 15 weeks of gestation and with all cases except one, it was possible to sample both twins by a single puncture. We suggest that early amniocentesis (14-15 weeks) by a single abdominal puncture could be a reliable and safe alternative to first-trimester chorionic villus sampling in twin pregnancies.

Amniocentesis↗
PubMed1993

Miscarriage diagnosis and gestational age estimation in the early first trimester of pregnancy: transabdominal versus transvaginal sonography.

A comparison is made between 290 patients examined using transabdominal sonography and 308 patients examined using transvaginal sonography. Patients with suboptimal menstrual histories and threatened miscarriages were excluded from these two groups of patients. The transabdominal and transvaginal sonography examinations were carried out while the patient's bladder was empty, so that there was no delay between the clinical and sonographic examinations. In this way there was no patient discomfort from a full bladder. In normal pregnancies after 42 days of amenorrhea, the percentage visualization rates of the chorionic sac, of the embryo with heart activity and of the yolk sac were measured. There were no significant differences between the two groups. The two techniques were able to provide a reliable diagnosis of miscarriage on embryos >or= 4 mm or with chorionic sacs >or= 10 mm mean diameter. However, before 42 days of gestation, transvaginal sonography was better than transabdominal sonography at diagnosing miscarriage. The percentage of anembryonic pregnancies was higher in the transabdominal sonography group (21%) than in the transvaginal sonography group (7%), despite similar gestational ages at the time of a positive diagnosis. Thus, a transabdominal scan can be used after 42 days and borderline cases can be referred for transvaginal sonography for confirmation.

Journal Article↗
PubMed1993

Intra-amniotic pressure is not affected by amniocentesis between 13 and 18 weeks of gestation.

Changes in amniotic fluid pressure before and after amniocentesis fell within the range of +/- 5 mmHg, except when uterine contractions were present. Intra-amniotic pressure is not affected by amniocentesis between 13 and 18 weeks of gestation. Amniotic fluid pressure was recorded in 82 pregnancies of patients undergoing genetic amniocentesis to determine whether sampling of amniotic fluid between 13 and 18 weeks changed intra-amniotic pressure. Pressures were recorded through a needle and saline filled catheter with a zero-level at the needle tip. Amniotic fluid pressure was unrelated to gestational age (P = 0.962) during the weeks we performed our measurements. Fluid samples of 12.6% of the total volume in a group of early genetic amniocentesis (n = 65) and of 7.5% of the total volume in a group of late genetic amniocentesis (n = 17) did not change significantly amniotic fluid pressure values. An increase in pressure of more than 5 mmHg only occurred in cases where uterine contractions were present. Other than these cases, all pressure change values fell within the range of +/- 5 mmHg. No difference in pregnancy outcome were present within the two groups. An argument for a standard method for stationing pressure is presented.

Amniocentesis↗
PubMed1992

Predictability of duration and severity of congenital hydronephrosis as a cause of smooth muscle deterioration in pyelo-ureteral junction obstruction.

Between 1989 and 1990, 31 new unilateral PUJO, prenatally diagnosed (16th-37th week of gestational age), underwent pyeloplasty between 19 and 105 days of age. The correlation between severity (V) (volume of hydronephrotic kidney) and duration (dT) of congenital hydronephrosis from its first detection in utero to surgery and histological findings were prospectively evaluated in this series. A dT longer than 70 days and a V larger than 50 ml., were considered as predictable for hypotrophy with fibrosis of the upper urinary tract smooth musculature. In conclusion, time seems to play an important role in the increase of the volume of the obstructed urinary tract to the extent of a large-scale hydronephrosis.

Female↗
PubMed1992

Red cell and plasma ferritin in a group of normal fetuses at different ages of gestation.

Plasma and cell ferritin were determined in 47 normal fetuses at different gestational ages in order to evaluate fetal iron status. Plasma ferritin shows an increase during pregnancy (17.7 micrograms/l-mean geometrical value of fetuses between 18 and 20 weeks; 56.8 micrograms/l mean geometrical value of fetuses between 32 and 35 wk) and significantly correlates to hemoglobin and number of red blood cells. Red cell ferritin, too, increases throughout pregnancy (from 92.7 ag/cell to 265 ag/cell) and shows a better correlation to hemoglobin and number of red blood cells. Experimental evidence has been provided showing that the placenta takes up ferritin and is important in iron storage and transport (even against a concentration gradient). Our data support this theory and suggest a situation of positive balance between iron uptake and utilization during intrauterine life.

Erythrocytes↗
PubMed1990

Genetic amniocentesis: 505 cases performed before the sixteenth week of gestation.

Between May 1987 and November 1988, 505 early amniocentesis within the 15th week of gestation were performed at the First Department of Obstetrics and Gynaecology, 'L. Mangiagalli' of the University of Milan and at the Department of Obstetrics and Gynaecology of 'Gaslini' hospital in Genoa. A total number of ten abnormal fetal karyotypes were diagnosed. In addition, one case of pseudomosaicism (not confirmed on fetal blood) and one case of osteogenesis imperfecta type II (observed at ultrasound examination) were also detected. Eleven pregnancies were therefore terminated because of an abnormal fetus. Out of 494 pregnancies (excluding terminated pregnancies) there were 16 fetal losses within the 28th week; ten of these occurred in the 2 weeks following the procedure. There were 475 live-births, of which 447 were term deliveries and the other 28 deliveries occurred before the 37th week of gestation.

Amniocentesis↗
PubMed1989

Trisomic 22 placenta in a case of severe intrauterine growth retardation.

We describe a case in which a trisomic 22 placenta could be the cause of severe growth retardation in a chromosomally normal female fetus. At amniocentesis a mosaic 46,XX/47,XX, +22 was observed in amniotic fluid specimens sampled on two different occasions, while fetal blood from a diagnostic cordocentesis revealed a normal chromosome constitution. Postnatal studies showed the consistent presence of trisomic 22 cells in the placenta, while only normal metaphases were found in amnion, blood, and fibroblast cultures.

Chorionic Villi↗
PubMedDate not supplied

Percutaneous umbilical blood sampling: indication changes and procedure loss rate in a nine years' experience.

A 9 years' experience with percutaneous umbilical blood sampling (PUBS) has been appraised. A total number of 1,272 procedures have been performed in our institution between 1986 and 1994; 861 before the 24th week of gestation and 411 after 24 weeks. The indications for PUBS changed throughout these years because of the rapid evolution of molecular biology and because of the fact that certain conditions can now be diagnosed at earlier stages of gestation by chorionic villi sampling and amniocentesis. Sampling at a later gestational age reflected changes in indications. PUBS loss rate has been calculated for 482 fetuses less than 24 weeks, retrospectively found to be negative for the suspected condition and has been related to gestational age, duration of the procedure and number of needle insertions. Total procedure-related loss rate was 2.3%: 1.6% intrauterine fetal deaths within 48 h of the procedure and 0.7% spontaneous abortions in the 2 weeks following the procedure. Gestational age at the time of the procedure and duration of the procedure were significantly related to fetal losses within 48 h.

Abortion, Spontaneous↗
PubMedDate not supplied

[Serotonin and hypertension in preeclampsia-eclampsia syndrome].

The preeclampsia-eclampsia syndrome is a severe complication of the third trimester of pregnancy and represents the first cause of maternal death. It is mainly characterized by: weight increase, proteinuria and hypertension and can evolve with convulsions and maternal death. The etiology still remains unknown although a series of events have been identified, starting with endothelial damage and local vasoconstriction leading to hypertension. These events occur at first locally in the placental district and become generalized. This paper reports experimental and clinical data in order to demonstrate: 1) the presence of a substance that could evoke experimentally the damage present in this syndrome, 2) a mechanism that delivers such a substance to its primary action site, the placenta, and 3) the possibility to inhibit either the substance or the delivery mechanism in order to prevent this disease. Serotonin appears to play an important role in the chain of events leading to preeclampsia. Certain histological aspects, present in pregnant women with this type of hypertension, have been observed in experimental animals after the administration of serotonin. Platelet derived serotonin could be sufficient, in the case of endothelial damage, to determine vasospasm. In a condition of hypercoagulability, such as pregnancy, this situation can trigger a chain of mechanisms ending with renal damage. Low dose aspirin seems a valid therapeutic approach reducing thromboxane concentrations and therefore preventing vasospasm. In this way the pathogenetic sequence culminating in the preeclampsia-eclampsia syndrome is interrupted. Ketanserin inhibits the hypertensive potential of serotonin by selectively acting on S2 serotonin receptors and appears to be an effective treatment in this type of pregnancy induced hypertension.

Adult↗
PubMedDate not supplied

[Sampling fetal blood from the umbilical cord under echographic guidance].

The performance of 465 sonographically guided percutaneous umbilical blood samplings and its use in the management of diagnostic problems in the second and third trimester of pregnancy are described. The method has been employed in the prenatal assessment of 423 patients (357 procedures in the second trimester and 108 in the third trimester). Pure fetal blood was obtained in all third trimester samplings whilst in the second trimester in 4 cases (1.1%) fetal blood could not be obtained at the first procedure and in 9 cases (2.6%) contamination with maternal blood or amniotic fluid was observed. Data analysis confirm how this simple and rapid procedure offers access to the fetal circulation for diagnostic and therapeutic purposes.

Blood Specimen Collection↗
PubMedDate not supplied

[Evaluation of the fetal risk after echo-guided blood sampling from the umbilical cord in the 2d trimester of pregnancy].

Fetal risk related to cordocentesis has been analyzed on a series of 222 ultrasound-guided fetal blood samplings for prenatal diagnosis of fetal diseases during the second trimester of pregnancy. Affected and malformed fetuses were excluded. Seven intrauterine deaths (3.2%) and 2 spontaneous abortions (0.9%) were observed. These figures proved higher than those observed in non-homogeneous series which consider the second and third trimester altogether. The fetal risk was significantly correlated with gestational age (less than 18 weeks 7.6% vs greater than 18 weeks 0.7% p = .02) and duration of the procedure (greater than 10'11.4% vs = less than 10'0.9% p = .0029). The number of abdominal insertions resulted in different death rates (greater than 1 ins. = 6.5% vs 1 ins. = 1.4%). It is likely that different developmental, anatomical and neurovegetative mechanism play a significant role in the risk rate found in the second trimester cordocentesis. These findings and the specific risk factors observed within the different technical conditions reported, must be taken into consideration for prenatal counseling.

Abortion, Spontaneous↗