Specific receptors for pituitary adenylate cyclase-activating polypeptide (PACAP), a novel peptide with neuroregulatory and neurotrophic functions, have been identified recently in different brain regions, including the hippocampus. In this study, we examined the effects of PACAP-38 on the excitatory postsynaptic field potentials (fEPSPs) evoked at the Schaffer collateral-CA1 synapses. Brief bath application of PACAP-38 (0.05 nM) induced a long-lasting facilitation of the basal transmission. Enhancement of this response was occluded in part by previous high-frequency-induced long-term potentiation (LTP). PACAP-38 did not significantly alter the paired-pulse facilitation (PPF). PACAP-38 has been shown to have a presynaptic effect on the septohippocampal cholinergic terminals, which results in an increase in basal acetylcholine (ACh) release. To assess whether the PACAP-38 enhancement of CA1 synapses was related to the activation of the cholinergic system we examined the effect of this peptide in the presence of atropine, a muscarinic receptor antagonist. The enhancement of the fEPSPs by PACAP-38 was blocked by bath application of atropine. These results show that PACAP-38 induces facilitation of hippocampal synaptic transmission through activation of the cholinergic system via the muscarinic receptors.

Animals↗

PubMedDate not supplied

Differential effects of PACAP-38 on synaptic responses in rat hippocampal CA1 region.

Pituitary adenylate cyclase-activating polypeptide (PACAP-38) is a member of the vasointestinal polypeptide (VIP)/secretin/glucagon family of neuropeptides for which neuroregulatory functions have been postulated. PACAP-38 receptors are expressed in different brain regions, including hippocampus. In this study, we examined the dose-dependent effects of PACAP-38 on the excitatory postsynaptic field potential (fEPSP) evoked at the Schaffer collateral-CA1 synapse in rat hippocampal slices. Bath application of low dose (0.05 nM) of PACAP-38 induced long-lasting facilitation of the fEPSP. This enhancement was blocked by the cholinergic receptor antagonist atropine and partially by the NMDA receptor antagonist 2-amino-5-phosphonovalerate (APV) and therefore, shares a common mechanism with LTP. In contrast, a high dose (1 microM) of PACAP-38 induced a persistent depression of the fEPSP that was not blocked by antagonists of cholinergic receptors (i.e., atropine and mecamylamine), adenosine receptors (i.e., DCPCX), or glutamatergic NMDA receptors (APV). Intermediate doses (0.1-0.5 microM) of PACAP-38 produced an initial decrease of the fEPSP followed by an enhancement. This decrease was not blocked by atropine whereas the facilitation was. These results show that PACAP-38 modulates CA1 synaptic transmission in a dose-dependent manner and that the peptide interacts with cholinergic and glutamatergic systems.

2-Amino-5-phosphonovalerate↗

PubMedDate not supplied

Long-term results of aggressive surgical treatment of primary and recurrent retroperitoneal liposarcomas.

The aim of this study was to establish the role of surgery in the treatment of retroperitoneal liposarcomas. Data concerning 28 patients submitted to surgery for retroperitoneal liposarcoma in our department over the period from 1972 to 1999 were reviewed retrospectively and analysed. Seventy-four operations were performed; in 54% of the operations it was necessary to resect contiguous organs (kidney 60%, colon 50%, adrenal gland 35%). In 89%, grossly curative resection was achieved at the first operation; 20 patients had at least one local recurrence after first operation (median time interval: 22 months). The mean follow-up was 80 months; median survival time was 51 months and 5-year actuarial survival time 51%. Patients with low-grade liposarcoma showed a statistically significant improvement (P < 0.001) in median survival (153 months) versus those with medium- (37 months) and high-grade sarcomas (8 months). At present surgery is still the treatment of choice in the treatment of primary and recurrent liposarcoma; in the case of low-grade liposarcomas especially, an aggressive surgical approach can result in long-term survival.

Adolescent↗

PubMedDate not supplied

Aortic insufficiency. A multivariate analysis of incremental risk factors for operative mortality and functional results.

The object of this study was to establish which of four chosen preoperative parameters, namely NYHA functional Class, cardio-thoracic ratio (CTR), left ventricular end-diastolic pressure (LVEDP) and ejection fraction (EF), might affect, singly or in combination, the operative risk in isolated, chronic aortic insufficiency (AI). To this purpose we reviewed the records of all adult patients consecutively operated upon in our Department for isolated chronic AI, from 1979 to 1985. Patients with associated cardiac disease, transvalvular aortic gradient, recent endocarditis of a malfunctioning bioprosthesis were excluded from the study, leaving 89 consecutive patients (mean age 47.2 years) for evaluation. St. Jude or Duromedics mechanical prostheses were exclusively used for aortic valve replacement (AVR). Post-operatively all patients received long term anticoagulation. Follow up period ranged from 24 to 109 months (mean 61.8 months). The method of analysis was designed as follows: a) each patient was allocated a positive (+) or a negative (-) variable for the value of each parameter, b) five patient groups were formed on the basis of the free association of parameter variables, c) single variables and their association with early and late mortality, functional results as NYHA Class were compared by statistical methods (chi 2, Student's Test, Wilcoxon Test). The results of the study show: a) only EF significantly influenced early mortality (P less than 0.05), b) late mortality was significantly influenced (P less than 0.001) by NYHA Class and CTR, c) single parameter variables (+ or -) and or their association significantly conditioned functional results.

Aortic Valve↗

PubMedDate not supplied

[Fibrous dysplasia of bone. Considerations on 2 cases of a particular clinical evolution].

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Adult↗

PubMedDate not supplied

[Association of the cytogenetic pattern and latero-cervical metastasis of laryngeal cancer].

Although solid tumors, in particular carcinomas, play a much larger part in human morbidity and mortality than hematological neoplasias do, much less is known about the cytogenetic abnormalities that characterize them. Numerous classification schemes have been used in the subdivision of human tumors. Most often the tumors are classified according to the presumed cell of origin (epithelial, mesenchymal, neurogenic or germ cell tumors), their benignity or malignancy, differentiation features and histological growth pattern or anatomical site or organ of origin. In the following discussion, we analyse 12 cases of squamous cell carcinoma of the larynx. All teh sample were karyotyped using a direct chromosome analysis method. The method reported was highly successful and in several types of tumors showed the possibility of obtaining good banded metaphases. The purpose of this research was to attempt to define the chromosomal pattern of laryngeal carcinomas and, consequently, to correlated, it to histological grading and clinical evolution. In all the cases studied we found several chromosomal anomalies. In five of them clonal anomalies, such as the loss of chromosome 4; Robertsonian translocation t(13,14); rearrangement of chromosome 1 and chromosome 17 and the presence of similar markers, were observed. The characterization of the markers was made with an IN SITU hybridization technique using specific probes, followed also in order to define two particular markers involving chromosome 1 and t(13,14). We did not reveal a correlation between histological grading and karyotype, but we did find a correlation between tumor ploidy and latero-cervical metastases. The most important result seems to correlate the presence of latero-cervical metastases with a hypodiploid cell line (with less than 46 chromosomes) in the primary tumor. This could be an index of the ability of the tumor to invade the latero-cervical lymph nodes. If this correlation is confirmed, conservative neck dissection could be limited to N0 patients with a hypodiploid pattern. In conclusion, we feel that, if confirmed, the results of this research, may be widely applied in clinical medicine.

Carcinoma, Squamous Cell↗

PubMedDate not supplied

[Cytogenetic patterns in Warthin tumor].

Our systematic studies of different types of benign and malignant salivary neoplasms in humans were initiated about two years ago. Analysis of karyotypes revealed that virtually all tumors are associated with chromosomal abnormalities. That those abnormalities may also take part in tumor initiation and progression is suggested by the association of specific chromosome rearrangement with particular cancers. We here with report cytogenetical observation in five Warthin's tumors giving particular attention to the possible occurrence of cells with (a) a normal karyotype or with (b) numerical changes, either loss of the Y chromosome or monosomy 4. The present series od adenolymphomas was karyotyped by a direct chromosomal analysis method. The method reported was highly successful, in several types of tumors showing the possibility of having good banded metaphases. All Warthin's tumors showed stemline (S) with a normal karyotype. These normal cells constituted the only S in two cases and the primary S in the other three cases. The normal cells observed in all adenolymphomas could be interpreted as outgrowing stroma cells. Most types of previously well-studied benign human tumor types, however (meningiomas, pleomorphic adenomas, lipomas), has a S group with a normal karyotype, regardless of the the tissue culture technique used. Thus, we believe that these normal cells usually represent neoplastic elements. Furthermore, we think that all benign tumors originate with a rather normal S, which, however, as the first indication of neoplastic transformation, shows chromosomal instability, such as the loss of chromosomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenolymphoma↗