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Biomedical subjects

C Mazza

Publications and source records attributed to C Mazza.

At least 55 records · Page 3Linked to original sources
PubMed1988

Genetic mapping of the Saccharomyces cerevisiae DNA polymerase I gene and characterization of a pol1 temperature-sensitive mutant altered in DNA primase-polymerase complex stability.

The cloned DNA polymerase I gene has been used to map the POL1 locus on the left arm of chromosome XIV, between MET4 and TOP2. Temperature-sensitive mutants in POL1 have been obtained by in vitro mutagenesis of the cloned gene and in vivo replacement of the wild-type allele with the mutated copy. Physiological and biochemical characterization of one temperature-sensitive mutant (pol1-1) shows that cells shifted to the non-permissive temperature can complete one round of cell division and DNA replication before they arrest. Analysis of DNA polymerase I in crude extracts and in partially purified preparations indicates that the pol1-1 mutation results in a conformational change and affects the stability of the DNA primase-polymerase complex.

Chromosome Mapping↗
PubMed1986

[Intracranial aneurysms and subarachnoid hemorrhage in children and adolescents].

42 cases concerning symptomatic intracranial circulation aneurysms and spontaneous SAH have been observed by the authors during the period 1965-1984; 37 of them were treated from 1970 on. This group represents 2.6% in the number of patients treated for SAH during the above mentioned period in the series of Pavia and Verona Neurosurgery. In 7 cases angiography did not evidence any malformation responsible for the hemorrhage. These cases have been defined as "sine materia" SAH. In 33 cases was documented the presence of an intracranial aneurysm as responsible for the hemorrhage. In the 2 remaining cases was found an aneurysm that even if unbroken had manifested itself. In 4 cases aneurysms were mycotic ones. The most frequent sites of aneurysms have been the carotid artery bifurcation and the middle cerebral artery 24% each one followed by the anterior communicating artery 21%. 5 patients were younger than 4 years and each one had peculiar clinical features. The 37 remaining patients were older than 9 years and have been subdivided in 2 groups: 16 patients from 9 to 15 years old in who the most common site of the aneurysm was the carotid artery bifurcation and the middle cerebral artery (31%) and the frequency of intracerebral hematoma was 50%; 21 patients from 16 to 20 years old in who the most common site of the aneurysm was the anterior communicating artery (33%) and the presence of an intracerebral hematoma was markedly inferior (14%). 23 of the 35 patients having an aneurysm underwent a surgical procedure for its exclusion. Operative mortality rate was nearly 5% and morbidity rate was nearly 12%. 5 patients who were in agony when admitted were not operated; 5 patients had a conservative therapy and in 2 of them an angiography performed at distance from the hemorrhage revealed the disappearance of the aneurysm. Clinical disturbances bound to ischemic phenomenons by cerebral vasospasm were observed in only 3 patients--all of them older than 17--in who a CT scan had showed a conspicuous cisternal blood suffusion. In 13% of cases appeared hydrocephalus and only in 3 cases was necessary to perform a shunt. The global results of therapy have been significantly better than in adults having 74% of good results and 19% of deaths. This prognostic improvement is probably due both to the well known recovery from neurological failure in young patients and to the very low incidence of ischemic manifestations from vasospasm in this range of age.

Adolescent↗
PubMed1986

Intracranial aneurysms and subarachnoid hemorrhage in children and adolescents.

Thirty-eight cases of symptomatic cerebral aneurysms or spontaneous subarachnoid hemorrhage in children and adolescents were observed from 1965 to 1984; 33 cases were treated from 1970 to date. This group represents 2.6% of the total number of patients with subarachnoid hemorrhage treated at our institute in the same period. The cause of subarachnoid hemorrhage was unknown in 7 cases; an intracranial aneurysm had ruptured in 29 cases, and was unruptured but symptomatic in 2 remaining cases. Three aneurysms were mycotic. The most frequent aneurysmal locations were the internal carotid bifurcation and the anterior communicating artery; peripheral branches of the middle cerebral artery were also a relatively common location. Four patients were 3 years of age or younger: each presented peculiar clinical features, and 3 of the 4 had middle cerebral artery aneurysms. The remaining 34 patients were all above 9 years of age. Two groups were identified: (a) in 14 patients between 10 and 15 years of age, the aneurysm was most commonly at the internal carotid bifurcation (37%), and an intracerebral hematoma was observed in 50% of these cases; (b) in 20 patients between 16 and 20 years of age, the most common aneurysmal location was the anterior communicating artery (35%), and intracerebral hematomas were rare (10% of cases). Among patients with aneurysms, 19 underwent surgical exclusion by clip, with 10% morbidity and 5% mortality; 5 patients in moribund conditions were not operated on; 5 patients were conservatively treated; in 2 patients the aneurysm had disappeared at a second angiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Childhood cerebrovascular diseases not associated with vascular malformations.

Of 76 patients in the pediatric age group suffering from cerebrovascular diseases treated in the years 1970-1983, 26 patients (34%) did not harbor intracranial vascular malformations (aneurysms or arteriovenous malformations). Two groups of patients were identified: (a) those suffering from a spontaneous intracranial hemorrhage (16 cases); (b) those suffering from an ischemic stroke (10 cases). Of those with spontaneous intracranial hemorrhage, 10 patients underwent surgery and evacuation of the hematoma. In 2 cases the hematoma was located in the posterior fossa, in 1 case in the upper brain stem, and in 3 cases in the basal ganglia; in the remainder the hematoma was supratentorial. Two patients died soon after the hemorrhage. Eight of the surviving patients completely recovered. In those with ischemic stroke, none suffered from congenital heart disease, a well-known predisposing factor. In this second group 1 patient died and 9 survived. Only one patient showed complete recovery. The data indicate that a hemorrhagic stroke is more common than an ischemic stroke in a child presenting with acute onset of hemiparesis and/or loss of consciousness: thus the value of CT scan as the first diagnostic procedure is clear, owing to the possibility of emergency surgical treatment. In children with ischemic strokes, a complete laboratory/clinical evaluation should be undertaken in order to exclude preexisting heart disease, coagulation disorders or lipoprotein abnormalities, and less common systemic diseases.

Adolescent↗
PubMed1985

Spontaneous disappearance of a large middle fossa arachnoid cyst.

A case of a large middle fossa arachnoid cyst that spontaneously disappeared is reported. The possible mechanisms involved in the "natural cure" of this lesion and the indications for surgical versus conservative treatment of middle fossa arachnoid cysts are discussed.

Adolescent↗
PubMed1983

Intracranial arteriovenous malformations in the pediatric age: experience with 24 cases.

24 patients below 16 years of age with intracranial arteriovenous malformations are considered. Presenting history has been constituted mainly by intracranial hemorrhage, followed by epilepsy and hydrocephalus. The utility of angiography and CT scan is stressed, especially for preoperative evaluation. The arteriovenous malformation was located in noncritical cortical areas in 7 cases, in critical cortical areas in 6 cases, in the midline structures or in the basal ganglia in 8 cases, in the posterior fossa in 2 cases, and was only dural in 1 case. Complete surgical resection of the lesion has been carried out in 18 cases, and embolization in 1 case. The operative microscope, induced hypotension, and the 'backward technique' have been very useful during surgery. Following the operation, good results have been achieved in 83% of cases; mortality has been 11%. In most cases epilepsy has shown improvement after surgery. It is concluded that direct surgical extirpation of the angioma is the treatment of choice for pediatric patients, even in the presence of epilepsy alone.

Adolescent↗
PubMed1982

Traumatic extradural haematomas in children: experience with 62 cases.

Sixty-two children with traumatic extradural haematomas are considered According to the clinical history presented--often atypical--and to the grade of neurological impairment, patients have been divided into different clinical groups. Nearly 50% of patients sustained a minor injury, and 26% did not lose consciousness after trauma. Twenty-four per cent of patients did not show fractures on skull X-rays. Atypical location of the haematoma was noted in 22 cases, mainly in the anterior fossa (19 cases). Sixty patients were operated on, while two patients were conservatively treated, owing to the limited size of the haematomas and to the absence of neurological deficits. Associated brain lesions were discovered at surgery in 40% of cases. The overall mortality rate has been 17%, the operative mortality rate 14%. The morbidity rate has been 6%, with 3% of patients presenting severe disability. Morbidity and mortality have been shown to be affected by age--with better prognosis in patients under 10 years of age, by the clinical history presented, by the preoperative conditions, and, mainly, by the presence of associated brain lesions. As regards location, frontal haematomas have shown a better prognosis and a slower course than convexity haematomas. Finally, prognosis of extradural haematomas in children has improved to some extent in the last years with the advent of the CT scan, possibly due to speed and accuracy of diagnosis.

Adolescent↗
PubMed1982

Midline giant arterio-venous malformations in infants.

Three rare cases of giant midline arterio-venous malformations are presented. The first case is an infant girl with a vein of Galen malformation, who died from a subarachnoid haemorrhage a few weeks after shunt insertion for the control of hydrocephalus. The second case is an infant girl with a massive dilatation of the superior longitudinal sinus, who died from acute cardiac decompensation following direct surgery on the malformation. The third case is an infant boy with very large bilateral angiomas of the basal ganglia, who was not treated surgically. Some unusual features of these cases are discussed. Anatomically, the lesion can be quite different from a typical vein of Galen malformation. Clinically, the presence of cardiac failure and hydrocephalus is not always the case, and the possibility of a subarachnoid haemorrhage must be considered. For these reasons, infants with giant midline AVMs should be treated individually, balancing various considerations.

Basal Ganglia↗
PubMed1981

An unusual case of meningeal gliomatosis.

A case of meningeal gliomatosis following a primary spinal cord tumor is reported. The clinico-pathological features of this unusual extension of a spinal glioma are described. The rare incidence of this malignancy and its occurrence in young patients only are stressed. The possible pathophysiological events leading to the diffuse dissemination of the neoplastic cells are discussed.

Adult↗
PubMed1981

Treatment of medulloblastoma in children: long-term results following surgery, radiotherapy and chemotherapy.

Forty-seven children with histologically confirmed medulloblastoma are considered. Forty-five cases were surgically by direct approach to the tumour, while two cases were treated only with a shunt. A shunt was inserted preoperatively in 14 cases, postoperatively in 4 cases. Surgical resection was total or subtotal in 52% of cases, partial in 35%, and limited to a biopsy in 13%. Radiation treatment to the entire neuraxis was done in 37 cases: 10 of these cases received additional chemotherapy--mostly with CCNU--as primary treatment for medulloblastoma. Ten patients died within 30 days after surgery. Twenty-two patients died months after treatment, mainly from tumour recurrence (19 cases). One patient was lost to follow-up. Thirteen patients are survivors from 10 months to 20 years after treatment. As a whole, the one year survival rate has been 67%, 3 year survival 43%, and 5 year survival 27%. Complications affecting prognosis have been presented by tumour recurrence and metastases. CSF shunting and lack of prophylactic irradiation to the cerebral hemispheres have been considered responsible for the high incidence of supratentorial metastases in our series. Factors influencing prognosis have been the extent of tumour resection and association of primary chemotherapy with radiotherapy. Within 3 years after surgery survival has been 52% in cases with total resection against 31% in cases with partial resection of tumour. As regards chemotherapy, 3 year survival has been 60% for patients with combined treatment (chemo- and radiotherapy) against 37% in patients with radiotherapy alone. It is concluded that the best results in children with medulloblastoma are achieved by a radical resection, associated with a combined primary treatment of radiotherapy and chemotherapy.

Adolescent↗
PubMed1980

Results of treatment with ventriculoatrial and ventriculoperitoneal shunt in infantile nontumoral hydrocephalus.

The authors present the results of surgical treatment in 165 children with nontumoral hydrocephalus, treated during a period of 11 years. The minimum period of follow-up was 1 year. The results in the group of children treated with a ventriculoatrial (VA) shunt were compared to those obtained in the group with a ventriculoperitoneal (VP) shunt. 45% of patients with VA shunts had one or more revisions, against 51% of patients with VP shunts. However, the incidence of revisions after 6 months from primary insertion was lower in the VP-shunted children. Most revisions were due to shunt malfunction: obstruction of the ventricular or abdominal catheter was the commonest finding. Among complications, the most serious was constituted by shunt infection (11% of cases). Most infections occurred at less than 2 months from surgery and were caused mainly by Staphylococci. 31% of infected patients died. Other frequent complications were due to shunt tubing lost in abdomen or in the ventricles and subdural hematoma. The overall mortality rate in the whole group was 18%, while the shunt-related mortality rate was 10.9%. Complications were more frequent in the VP-shunted patients, but were less than in VA-shunted patients and accounted for a lower mortality rate. Complications and mortality rate were prevalent in the patients presenting congenital communicating hydrocephalus or myelomeningocele. It is concluded that VP shunt is preferable to VA shunt in the treatment of infantile hydrocephalus.

Cerebrospinal Fluid Shunts↗
PubMed1980

[Extracranial metastases from medulloblastoma: report of four cases (author's transl)].

Four cases of bone and pulmonary metastases of medulloblastoma histologically diagnosed and with an exhaustive clinical-radiological and scintigraphic documentation, are described. In three patients, one of which non operated, the metastases of the osteolytic and osteoblastic type affected diffusely the skeleton; in the fourth patient the bone lesions were associated with a single pulmonary metastasis. The modality of metastatic spread and the clinical course of the illness in the diagnostic and therapeutic aspects are discussed.

Adolescent↗
PubMed1979

Arteriovenous aneurysm of the vein of Galen. A clinical, angiographic CT scan and neuropathological study.

An autopsied case of arteriovenous aneurysm of the vein of Galen in a 31/2-month-old female is reported. Arteriovenous aneurysm of the vein of Galen is a rare vascular malformation of the central nervous system consisting of a saccular dilatation of the vein which receives blood shunted through enlarged arteries. These peculiar structural and hemodynamic characteristics differentiate this particular malformation from the other AVMs of the central nervous system. In infants the arteriovenous aneurysm of the vein of Galen is characterized clinically by hydrocephalus and cardiomegaly. In the present paper the clinical features and diagnostic indications are discussed and, in particular, the role of computerized cranial tomography (CT) is emphasized as a rapid and noninvasive procedure for detection of intracranial disorders.

Brain↗