Independent Component Analysis (ICA) is an important extension of linear Principal Component Analysis (PCA). PCA performs a data transformation to provide independence to second order, that is, decorrelation. ICA transforms data to provide approximate independence up to and beyond second order yielding transformed data with fully factorable probability densities. The linear ICA transformation has been applied to the classical statistical signal-processing problem of Blind Separation of Sources (BSS), that is, separating unknown original source signals from a mixture whose mode of mixing is undetermined. In this paper it is shown that Oja's Nonlinear PCA algorithm performs a general stochastic online adaptive ICA. This analysis is corroborated with three simulations. The first separates unknown mixtures of original natural images, which have sub-Gaussian densities, the second separates linear mixtures of natural speech whose densities are super-Gaussian. Finally unknown mixtures of original images, which have both sub- and super-Gaussian densities are separated.

Algorithms↗

PubMedDate not supplied

Preoperative reduction of spondylolisthesis.

The treatment of SL, especially in some cases, is mostly surgical. This lesion can be considered an extremely localised kyphosis (only two vertebrae) or a localized (sub-)luxation: at most hearetically pre-operative reduction should represent the first stage of the treatment, also because reduction makes further surgery easier and enables us to obtain the best results. After a glance at the various surgical techniques that have been used in the past, we describe our method of preoperative reduction in case of severe SL, an improvement of Scaglietti's original technique. According to the parameters taken into consideration, spondylolisthesis (SL) of the 4th and, above all, the 5th lumber vertebrae can be considered, especially in severe cases, as kyphosis or displacement (or even dislocation in the case of ptosis). In SL-kyphosis the antero posterior axes of the contiguous vertebral bodies are no longer parallel but tend to over-impose one to the other anteriorly forming an open posterior angle of varying degrees. It is an extremely short kyphosis (only two vertebrae) but from all points of view, even therapeutic, it reflects the characteristics of all types of vertebral kyphosis. SL-subluxation or SL-luxation (ptosis) is characterized by the respectively partial or total loss of normal alignment between the vertebrae involved. This can be explained by the fact that nearly all those who have dealt with the problem of treating SL, especially of L5, always ask themselves beforehand if it is possible and/or opportune to eliminate or improve the condition before surgery. In other words the question of reduction (pre or intraoperative, partial or total) of more or less severe L5 SL is always considered by all authors, even if their conclusions are often in disagreement.

Adolescent↗

PubMedDate not supplied

Adenocarcinoma and epidermoid carcinoma of the lung in the elderly.

Primary lung carcinoma, in the elderly, presents some interesting epidemiologic and clinical characteristics. The authors, after reviewing the international literature, stress the differences of behavior and incidence of epidermoid carcinoma and adenocarcinoma occurring in elderly patients as compared to those found in younger patients. They report their experience which is similar to that reported in the medical literature.

Adenocarcinoma↗

PubMedDate not supplied

[A geriatric case of colonic angiodysplasia].

A case of colic angiodysplasia in an elderly patient affected by chronic renal failure is discussed. Different methods suitable for management of these vascular ectasies are briefly reported. Prominent role of colonoscopy in the diagnosis of such disease is emphasized.

Aged↗

PubMedDate not supplied

[Surgical treatment of inguinal hernias with local anesthesia].

Fifty-nine cases of inguinal hernia repair with local anesthesia are shown. The authors stress the advantages of this safe technique permitting an immediate postoperative ambulation and an early discharge of patients, thus reducing complications related a long term bed-stay.

Adult↗

PubMedDate not supplied

[Pulmonary hamartoma in geriatric surgery].

The pulmonary hamartoma is a kind of disease frequently shown in elderly. The diagnosis is often difficult and fine needle aspiration (FNA) can be used for histological features. CT scan can be also a such useful technique in differential diagnosis. A case is presented and its problems are discussed.

Aged↗

PubMedDate not supplied

[Cystic mesothelioma of the peritoneum: a clinical case report].

A case of cystic mesothelioma of the peritoneum, presenting as acute appendicitis is reported. The authors stress the difficulty of a correct preoperative diagnosis of this rare tumor, which however, may be considered benign, with a good long-term prognosis.

Adult↗

PubMedDate not supplied

Photodynamic therapy in general surgery.

Authors' experience in detecting neoplasms by a computerized telethermographic system in animal models is reported. The new technique seems to have a great potential as a photo-diagnostic method particularly when followed by the surgical treatment or the photodynamic therapy (PDT) of the neoplastic lesions. Literature reports on the PDT of tumors are reviewed.

Animals↗

PubMedDate not supplied

[Morgagni-Larrey hernia: 2 clinical cases].

The authors report two cases of hernia of Morgagni, respectively observed in a 42-year-old man and in a 16-year-old boy. In the first case the diagnosis was previous (20 yrs.) to surgical treatment. On the contrary, in the second case the diagnosis was not possible before surgery because of the patient's young age and mild symptoms. Surgical treatment, through thoracotomy in the first case and laparotomy in the second one, was able to repair the diaphragmatic gap.

Adolescent↗

PubMedDate not supplied

[A rare case of a giant intra-abdominal mesocolic liposarcoma].

Intra-abdominal liposarcomas (IALS) represent a rare localization compared to other liposarcomatous (LS) sites such as the lower extremities and the retroperitoneum. The authors report their experience in a case of giant liposarcoma (weight: Kg 8.2) presenting a massive intra-abdominal extension. Diagnostic and therapeutic problems related to this type of neoplasm as well as a literature review are reported.

Aged↗

PubMedDate not supplied

[Primary space-occupying lesions in the mediastinum].

Authors report four cases of mediastinal tumors. X-rays, CT scan, bronchial endoscopy, angiography and mediastinal endoscopy can be useful to diagnose this kind of neoplasms. Surgical treatment and, further, radio or chemotherapy are used in case of mediastinal neoplastic lesions. Unfortunately, lifetime longer than five years is observed just in 50% of the patients.

Adult↗

PubMedDate not supplied

[A rare case of cavernous hemangioma of the internal malleolus].

Explore the source record for details and available documents.

Bone Cysts↗

PubMedDate not supplied

[Effect of gamma ray sterilization on the expanding endo-orthosis for flatfoot].

Explore the source record for details and available documents.

Flatfoot↗