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Biomedical subjects

M Sacher

Publications and source records attributed to M Sacher.

At least 55 records · Page 3Linked to original sources

Identification of cytochrome P450IA2 as a human autoantigen.

Autoantibodies occurring in a patient with idiopathic autoimmune type chronic active hepatitis (CAH) were found to react with purified rabbit cytochrome P450IA2 and to a much lesser extent with P450IA1. Both cytochrome P450s are known to be inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the rabbit, and the expression of the microsomal protein recognized by the patient serum was induced in adult rabbit livers after treatment with TCDD. This protein is only weakly detected in liver microsomes from neonatal rabbits exposed to TCDD in utero, which is consistent with the age-dependent induction of P450IA2 by TCDD. The serum specifically reacted with a protein of similar size in microsomes prepared from COS-1 cells transfected with an expression vector containing the full length human P450IA2 cDNA. This reactivity was not detected in the cells transfected with the vector alone, indicating that the antibody recognizes human P450IA2. In addition, the serum extensively inhibited 7-ethoxyresorufin O-deethylation catalyzed by isolated human liver microsomes. This catalytic activity is associated with class IA P450s in other species. A screen of sera from patients with various hepatic and nonhepatic diseases indicates that the autoantibody to P450IA2 occurs rarely in CAH. Cytochrome P450IA2 becomes the third P450 identified as an autoantigen in inflammatory liver diseases.

Adult↗

Chronic active hepatitis associated with vitiligo, nail dystrophy, alopecia and a new variant of LKM antibodies.

In this report we describe the case of a 7-year-old boy, suffering from autoimmune-type chronic active hepatitis (AI-CAH) associated with vitiligo, nail dystrophy, alopecia areata and a variant of liver kidney microsomal (LKM) autoantibodies. This patient's antibodies are different from LKM-1 which are directed against cytochrome P450 db1. They react predominantly with perivenous hepatocytes in contrast to LKM-1 antibodies which homogeneously stain the whole liver lobule in immunofluorescence. In Western blot analysis this LKM variant reacts with a liver microsomal protein of approx. 50 kDa, but not with recombinant LKM-1 (cytochrome P450 db1) antigen. Immunosuppressive treatment led to a normalization of liver histology after 1 year and a significant improvement of vitiligo and alopecia areata. In summary, a case of autoimmune-type chronic active hepatitis is presented which is associated with a new variant of LKM antibodies reacting with a 50 kDa microsomal protein different from cytochrome P450 db1. Furthermore, this patient suffers from extrahepatic syndromes (alopecia, nail dystrophy) that have not been described previously in LKM antibody-positive chronic active hepatitis.

Alopecia↗

Magnetic resonance imaging and computed tomography of an intraventricular craniopharyngioma.

The computed tomography (CT) and magnetic resonance imaging (MRI) appearances of an intraventricular craniopharyngioma are discussed. The unusual CT appearance of our case is compared to the previous 13 cases in the CT literature. The MRI scan represents the only known description of an intraventricular craniopharyngioma in the current literature. The characteristics of our case are compared to the MRI appearance of suprasellar craniopharyngiomas.

Adult↗

Clonal analysis of infiltrating T lymphocytes in liver tissue in viral hepatitis A.

The pathogenic mechanism leading to liver tissue injury in hepatitis caused by hepatitis A virus is unclear. We have randomly established T-cell clones from liver biopsies from four patients with hepatitis A. A total of 578 clones was phenotypically analysed. During the acute phase of the disease CD8+ clones dominated over CD4+ clones, whereas in a biopsy taken late after onset of clinical syndromes more CD4+ than CD8+ clones were obtained. Interestingly, in a patient with a second exacerbation of the disease, more than 20% of all clones had the CD3+ WT31- CD4- CD8- 'NK-like' phenotype. All CD8+ clones had cytotoxic activity and approximately 50% of all CD8+ clones showed specific cytotoxicity against autologous fibroblasts infected with hepatitis A virus. The CD8+ cells also produced IFN-gamma in response to these target cells. Variable IFN-gamma production was observed with all types of T-cell clones. These results suggest that the liver injury in hepatitis A is not caused by a viral cytopathogenic effect but is due to an immunopathological reaction of sensitized cytotoxic T lymphocytes against infected hepatocytes. In addition, these studies show an enrichment of CD4-8-T-cell receptor alpha beta-chain-negative T lymphocytes at the site of an inflammation and suggest a role of these cells in an anti-viral reaction.

Acute Disease↗

Crohn's disease penetrating into the spinal canal.

An 11-year-old boy who had suffered from Crohn's disease of the large bowel for 4 years developed high fever, severe back pain and flexion-contracture of the right hip joint with inability to walk. After several weeks radicular irritation also became apparent. CT-scan demonstrated an abscess of the right psoas muscle that had also infiltrated the spinal canal, leading to a spinal extradural abscess extending from L2-S4. Therapy comprised surgical drainage of the psoas abscess and conservative therapy (mainly steroids and hypercaloric diet) and resulted in complete cure of the psoas and the spinal abscess. Spinal infiltration is a rare and serious complication of Crohn's disease and must be considered in every case of significant back pain with or without obvious neurological signs.

Abscess↗

The use of magnetic resonance and computed tomography in the management of a patient with intrasinus hemorrhage.

The judicious use of computed tomography and magnetic resonance imaging in a critically ill patient with leukemia is discussed to demonstrate how a rapid and accurate diagnosis of intrasinus hemorrhage was established, thereby avoiding an unnecessary invasive procedure in this high-risk patient. In this clinical setting, a brief T1-weighted study distinguished between blood and infection.

Adult↗

The bull's-eye sign of extracranial cervical aneurysms.

Extracranial, cervical aneurysms and arterial thrombosis are uncommon entities. In most cases, they have diagnostic clinical presentations. However, on occasion the history and physical findings do not clearly suggest their presence. In these cases, postcontrast computed tomography scans can aid in rapidly establishing the correct diagnosis by revealing a "bull's-eye" appearance within the mass (vessel lumen). The diagnosis is less difficult to make when the involved vessel is the carotid artery, because this artery is routinely identified on postcontrast computed tomography scans and the lesion can be easily placed along its course. The vascular origin of such a lesion is not usually evident on computed tomography if the process does not lie along the course of a major vessel. In these cases, the bull's-eye sign can establish the diagnosis so that prompt consideration can be given to angiography and therapy.

Adult↗

Common tumors of the parapharyngeal space: refined imaging diagnosis.

Computed tomographic (CT) scans and magnetic resonance (MR) images in 103 patients with either a deep-lobe parotid tumor extending into the parapharyngeal space, a minor salivary gland tumor, a neuroma, or a paraganglioma were reviewed. The parotid or extraparotid nature of these masses was established by identifying a fat plane between the mass and the parotid gland. This was more reliably accomplished with MR imaging than with CT. Although dynamic CT allowed identification of the glomus tumors, MR imaging also permitted diagnosis of these lesions. The inherent CT and MR imaging characteristics of most of the neuromas and minor salivary gland tumors were indistinguishable. However, the neuromas tended to displace the internal carotid artery anteriorly, whereas the salivary lesions displaced this vessel posteriorly. This artery was better identified on MR images than on CT scans. Thus, these lesions, which are the four most common primary parapharyngeal space tumors, can be distinguished on MR images by evaluating not only their inherent signal characteristics but also the surrounding fat planes and any displacement of the internal carotid artery.

Adenoma, Pleomorphic↗

[Life-threatening hemorrhage caused by vitamin K deficiency in breast-fed infants].

4 infants (2 males, 2 females) with acute bleedings due to vitamin K-deficiency beyond the neonatal period are reported. Two infants had intracranial haemorrhage and died. All infants were born appropriate for date and became no vitamin K-prophylaxis. All were breast-fed. This report is a further prove for the existence of the late onset haemorrhagic disease of the newborn. The importance of general vitamin K-prophylaxis is outlined.

Blood Coagulation Tests↗

The preoperative venogram in planning extended craniectomies.

A technique of extended craniectomy sometimes allows removal of large central or transtentorial mass lesions at a single operative sitting because it affords better exposure and control of normal structures. While seeking to avoid multiple craniotomies, this method requires permanent ligation of the transverse venous sinus. Unless there is adequate collateral venous drainage from the ipsilateral hemisphere, the patient is at risk for venous infarction in the post-craniectomy period. The purpose of this study is to propose a method of establishing the presence of collateral venous drainage preoperatively. Each carotid artery is injected with the head in a neutral position and with the head turned to the side ipsilateral to the carotid artery injection in an attempt to divert the venous flow. Fifty patients were examined using this method; seven were being evaluated for possible craniectomies. The technique identified nine patients with potential venous collaterals (20%). They would otherwise have been considered nonoperable: two of the six patients eventually operated upon (33%) fell into this category. In general, the operative procedure may be safe more often on the left than the right (45%) vs (20%). Particular attention must be given to the pattern of venous drainage from the posterior temporal lobe to avoid isolation of the venous drainage from this area.

Adult↗

Hemodynamic analysis of associated extracranial atraumatic vertebral artery aneurysm and arteriovenous fistula. Case report.

A case of atraumatic arteriovenous (AV) fistula of the extracranial vertebral artery associated with an atraumatic aneurysm of the contralateral extracranial vertebral artery is reported. The fistulous lesion was excised after distal and proximal ligation of the vessel. Subsequently, the contralateral aneurysm underwent spontaneous dissolution. Seven cases of extracranial vertebral AV fistulae associated with ipsilateral vertebral artery aneurysms (four traumatic and three as part of vascular dysplastic syndromes) have been reported previously.

Adult↗

[Dystonia as a complication of gastroesophageal reflux: Sandifer syndrome].

A girl aged 4 years and 5 months was admitted because of vomiting, poor appetite, epigastrial pain, weight loss and an abnormal posturing of the head and neck since the age of 3 1/2 years. This abnormal posturing consisted of maximal lateral flexion of the head and neck to the left. A number of investigations including EEG and CT-Scan of the head, had been performed repeatedly, and despite normal results various neuropsychiatric diagnoses were made. In our hospital massive gastrooesophageal reflux and oesophagitis were demonstrated and the diagnosis of Sandifer's syndrome was established. A fundoplication was performed and the child is free of symptoms since.

Child, Preschool↗