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P Sartori

Publications and source records attributed to P Sartori.

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↗
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↗
PubMed2003

Gastrointestinal carcinoids. Prognosis and survival.

BACKGROUND: Gastrointestinal carcinoid tumors are rare and little is known about factors related to prognosis in patients with carcinoid disease. Aim of this study is to determine the impact of clinical presentation variables on the management and survival. METHODS: We have evaluated 31 consecutive patients with gastrointestinal carcinoid tu-mours who underwent surgical intervention at the I Department of Surgery of Milano-Bicocca University over 15 years (1985-1999). Tumor distribution, hormone production, prognostic factors and survival were analysed. RESULTS: Carcinoid syndrome was the only clinical pattern diagnostic of carcinoid tumour. Most common symptoms were abdominal pain (64%), nausea and vomiting (48%). High levels of urinary 5-hydroxyindolacetic acid were significantly associated with carcinoid syndrome and metastatic disease. Tumor size, depth and gender were significant predictors of metastases. Age, gender, tumor size, metastatic spread and location were statistically significant predictors of death. CONCLUSIONS: Clinical presentation was non specific except for those patients affected by carcinoid syndrome. Ten years overall survival was 43%, with 52% metastatic spread incidence. The extent of surgical resection should be modulated on patient related risk factors. Poor prognostic factors affecting survival were: age, gender, metastatic disease, depth of invasion and tumour size.

Adult↗
PubMed2001

Tumour lysis syndrome during anaesthesia.

We describe a child who developed acidosis, hyperkalaemia and cyanosis while emerging from an otherwise uneventful anaesthetic. A diagnosis of tumour lysis syndrome was suspected and confirmed biochemically. Although this syndrome is usually associated with chemotherapy and has been described to occur spontaneously, it has not previously been reported as being associated with anaesthesia.

Abdomen↗
PubMed2001

[Stomach lymphoma].

BACKGROUND: Primitive gastric lymphoma (PGL) is a rare tumour, and although its incidence is rising it is difficult to state the role of the various therapeutic methods in treating this disease. Aim of this study is to point out what sequence of treatment is more effective trying to find out some guidelines which can be useful in clinical practice. METHODS: Retrospective analysis of clinical data of 54 patients with PGL admitted at a University surgical department during 10 years. All the patients underwent neoadjuvant or adjuvant chemotherapy and D2 gastrectomy. Follow-up ranged from 6 to 120 months. Survival was related to: Mushoff's stage of disease, the grade according to the Working Formulation and the sequence of treatment. Statistical analysis was performed by Kaplan-Maier method and the difference between survival curves was compared by log-rank test. RESULTS: Mean postoperative hospital stay was 12 days and morbidity was 18%. Five and 10 years overall survival rates were 70 and 85%. There was a significant difference in survival between patients with high grade PGL and those with intermediate grade (p=0.0188) as well as in those with low grade (p=0.0435). Patients in stages IE-II1E had a significantly longer survival than those in stages IIIE-IVE (p=0.0123). Patients in stages IE-II1E underwent neadjuvant chemotherapy and surgery and survived longer than those in whom surgery preceded chemotherapy (p=0.0293) instead for patients in stages IIIE-IVE neoadjuvant chemotherapy shortened survival (p=0.0403). CONCLUSIONS: In personal opinion, in patients in stages IE-II1E chemotherapy should be carried out before surgery, while in those in stages IIIE-IVE the reverse scheme is more effective in achieving longer survival rates.

Adult↗
PubMed2000

[Hernia repair with prolene mesh according to the Lichtenstein technique. Results of 692 cases].

BACKGROUND: Inguinal hernia repair with prolene mesh according to Lichtenstein "tension free" technique has gained great acceptance worldwide, showing efficacy to consolidate the posterior wall of the inguinal canal and to reduce recurrence risk because of tension on suture lines and postoperative pain. Personal experience of 692 hernias treated with this technique is reported. METHODS: From January 1989 to December 1997, 692 patients were treated according to Lichtenstein at the General Surgery Department of the San Gerardo Hospital. Mean age was 60 years (range 18-88) with a male: female ratio of 13:1. Surgery was performed under local anesthesia in 185 cases, under epidural anesthesia in 317 and under general anesthesia in 190. Hernia was primitive in 647 cases (411 obliquo-external and 236 direct), while in 45 patients it was a recurrent hernia. In this series, 619 patients had monolateral inguinal hernia, while 73 had a bilateral one. In 40 cases hernia was incarcerated and in 8 strangulated. RESULTS: Mean hospital stay was 2.3 days (range 1-8). Eleven (1.6%) early complications, were observed, with one periprosthetic infection which resolved after patch removal, 3 hematomas, 2 seromas and 2 wound infections. Furthermore, there were 32 (4.6%) late complications with only one recurrence (0.14%) in this series and 25 cases of persistent nerve irritation. CONCLUSIONS: The results obtained with Lichtenstein "tension free" repairs of inguinal hernias confirmed this technique as easy to perform, also under local anesthesia, and associated with low rates of complications and without recurrences.

Adolescent↗
PubMed2000

[Sequential endo-laparoscopic treatment in patients with common bile calculi].

BACKGROUND: Laparoscopic treatment of common bile duct (CBD) stones is gaining great acceptance worldwide, but actually it requires skills and technologies too expensive for a great part of general surgeons. So endoscopic removal of CBD stones before cholecystectomy is usually performed. Since 1991 in our department we started a policy of selective preoperative cholangiopancreatography (ERCP) in patients suspected for choledocholithiasis and waiting for laparoscopic cholecystectomy. METHODS: A retrospective study has been made on a population of 1100 patients who underwent elective laparoscopic cholecystectomy in the period between January 1991 and December 1997. They were 391 male and 719 female with a mean age of 52 years, 126 of whom (11.5%) were selected to have ERCP preoperatively because they had clinical, biochemical and ultrasound signs of the presence of common bile duct stones (CBDS). RESULTS: Successful cannulation of the CBD was achieved in 124 cases (98.4%), with failures due to ampullary diverticula. In 7 cases (5.5%) a precut was necessary to obtain cannulation. Sphincterotomy was performed in 113 patients (89.7%). In 93 patients (73.8%) stones were found (87 macrolithiasis and 6 microlithiasis); in 91 (97.8%) stones were removed in one (87) or two (4) endoscopic session. There were 2 major complications (one bleeding and one severe pancreatitis) due to ERCP or a sphincterotomy. Two patients developed symptoms from unsuspected common bile duct stones after LC and were removed endoscopically. No complications during LC were due to ERCP or ES. CONCLUSIONS: Selective preoperative ERCP is an effective way of clearing the CBD stones before laparoscopic cholecystectomy, with low rate of complications related to endoscopic and laparoscopic procedures, and short mean hospital stay (5.5 days), according to the concept of minimally invasive treatment.

Adolescent↗
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↗
PubMed1997

Age-related decrease of the perineuronal satellite cell number in the rabbit spinal ganglia.

This study was undertaken to establish whether a change in the perineuronal satellite cell number contributes to the age-related reduction of the volume ratio between the perineuronal glial sheaths and their associated nerve cell bodies, observed to occur in rabbit spinal ganglia. The volumes of the nerve cell bodies and the numbers of the related satellite cell nuclei were estimated on serial semithin sections from young adult and old rabbits. As satellite cells are mononucleate, the number of the nuclei corresponds to that of these cells. The satellite cell sheaths in both age groups were also examined under the electron microscope. The mean number of satellite cells was significantly smaller in the aged animals than in the young adults although the mean volume of the nerve cell bodies was significantly larger in the former. Cytoplasmic vacuoles, invaginations of the connective tissue and autophagic vacuoles were more frequent in the old rabbits. Satellite cells with pyknotic nuclei and remnants of degenerated satellite cells were only found in aged animals, although rather rarely. The decrease in the satellite cell number is one of the mechanisms by which the age-related reduction of the volume ratio between the perineuronal glial sheaths and their associated nerve cell bodies takes place. The decrease in the satellite cell number seems to occur, at least in part, through cell degeneration. However, other mechanisms (e.g., detachment of satellite cells from the perineuronal sheaths) cannot be excluded. Since satellite cells play a role in neuronal support, the significant decrease in their number probably has negative consequences for neuronal activity.

Aging↗
PubMed1995

Inhibition of bovine beta-trypsin by the active site titrant N alpha-(N,N-dimethylcarbamoyl)-alpha-azaornithine p-nitrophenyl ester: a kinetic and X-ray crystallographic study.

Kinetics of the bovine beta-trypsin (trypsin) reaction with the active site titrant N alpha-(N,N-dimethylcarbamoyl)- alpha-aza-ornithine p-nitrophenyl ester (Dmc-azaOrn-ONp) was obtained at pH 6.2 and 21.0 degrees C. The results are consistent with the minimum three-step catalytic mechanism of serine proteinases involving a stable acyl.enzyme adduct. Dmc-azaOrn-ONp binds stoichiometrically to trypsin and allows the reliable determination of the active enzyme concentration between 1.0 x 10(-6) M and 3.0 x 10(-4) M. The three-dimensional structure of the trypsin.Dmc-azaOrn acyl.enzyme adduct has been solved by X-ray crystallography at 1.8 A resolution (R = 0.153). The Dmc-azaOrn moiety of the active site titrant is accommodated in the serine proteinase active center, occupying the S1 specificity subsite, and is covalently linked to the OG atom of the Ser195 catalytic residue.

Animals↗
PubMed1995

Crystallization and preliminary X-ray analysis of pyruvate kinase type I from Escherichia coli.

Crystals of the fructose-l,6-bisphosphate-dependent pyruvate kinase from Escherichia coli have been grown using the hanging-drop vapour-diffusion technique. The space group was found to be C222(1) with cell dimensions a = 76.8, b = 247.5, c = 132.6 A. Diffraction data to 3.0 A resolution have been recorded and the enzyme molecular symmetry analysed through inspection of the self-rotation function. The crystallized protein is in the allosterically inactive T state.

Journal Article↗
PubMed1995

Active site titration of bovine beta-trypsin by N alpha-(N,N-dimethylcarbamoyl)-alpha-aza-lysine p-nitrophenyl ester: kinetic and crystallographic analysis.

Kinetics of bovine beta-trypsin (trypsin) with the N alpha-(N,N-dimethylcarbamoyl)-alpha-aza-lysine p-nitrophenyl ester (Dmc-azaLys-ONp) was obtained at pH 6.2 and 21.0 degrees C. Dmc-azaLys-ONp shows the characteristics of an optimal active site titrant in that it (i) gives titrations in a short time, (ii) is a stable and soluble compound with a stoichiometric reaction that is easily and directly detectable, and (iii) allows titrations over a wide range of enzyme concentration. Moreover, the three-dimensional structure of the trypsin.N alpha-(N,N-dimet hylcarbamoyl)-alpha-aza-lysine acyl.enzyme adduct has been solved by X-ray crystallography at 2.0 A resolution (R = 0.145). The Dmc-azaLys moiety of the active site titrant is sited in the serine proteinase reaction center, and is covalently linked to the OG atom of the Ser195 catalytic residue.

Animals↗
PubMed1994

Allelic methylation of H19 and IGF2 in the Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth syndrome with associated embryonal tumours. Most BWS cases are sporadic but familial cases occur in 15% of patients and in these there is linkage to chromosome 11p15. In addition, a small number of patients have cytogenetic abnormalities involving chromosome 11p15. Approximately 20% of sporadic BWS patients have uniparental paternal disomy (UPD) of chromosome 11p15. This finding together with the observation that penetrance in familial cases depends on parental transmission, suggests that the gene(s) for BWS are imprinted. The recent demonstration of biallelic expression of the otherwise maternally imprinted IGF2 gene in some BWS patients implicates excess IGF2 expression in the disease. Here we have analysed the allele-specific methylation patterns in the IGF2 gene and in the neighbouring and reciprocally imprinted H19 gene in a group of 42 BWS patients, 10 of which were mosaic UPD cases. We found that allelic methylation of both genes was normal in all non-UPD cases, with the paternal allele being methylated, and was increased in UPD cases in proportion with the disomic lineage. These findings suggest that sporadic BWS is not associated with a general alteration of methylation imprinting of the IGF2 and H19 genes. The methylation assay used in this study thus also offers a simple and reliable diagnostic test of UPD for 11p15.5. An unexpected finding was a distortion of the frequency of AvaII alleles at the IGF2 locus exclusively in UPD BWS cases (P < 0.001). This further implicates the IGF2 gene in aspects of the BWS phenotype.

Alleles↗
PubMed1992

"Stem cell" origin of the hematopoietic defect in dyskeratosis congenita.

We have used the long-term bone marrow culture (LTBMC) system to analyze hematopoiesis in three patients with dyskeratosis congenita (DC), two of whom had aplastic anemia, and the third had a normal blood count (apart from mild macrocytosis) and normal BM cellularity. Hematopoiesis was severely defective in all three patients, as measured by a low incidence of colony-forming cells and a low level of hematopoiesis in LTBMC. The function of the marrow stroma was normal in its ability to support the growth of hematopoietic progenitors from normal marrows seeded onto them in all three cases, but the generation of hematopoietic progenitors from patients marrow cells inoculated onto normal stromas was reduced, thus suggesting the defect to be of stem cell origin. The parents and unaffected brother of one of the families have also been studied in LTBMC and all showed normal hematopoietic and stromal cell function. From this study we speculate that there are some similarities between DC and the defect in the W/Wv mouse.

Adolescent↗