Glycosaminoglycans in human trabecular meshwork: age-related changes

Glycosaminoglycans play a central role in maintaining the normal outflow resistance in the human trabecular meshwork. We evaluated the possible morphological, histochemical and morphometrical age-related changes in glycosaminoglycans of the trabecular meshwork. Small human samples were drawn from 24 eyes after exitus from young and old humans. Samples were harvested from the anterior chamber of the eye, without any aesthetic damage for the face. They were divided into three fragments, each used for morphological, histochemical and ultrastructural staining. Quantitative analysis of images was performed to evaluate morphometrical data that were statistically analysed. Our findings demonstrate the following age-related changes: (1) deposition of fibrous granular material in the trabecular meshwork; (2) increased electron density of the structures; (3) strong decrease in the hyaluronic acid content, and (4) increase in sulphated proteoglycans. Glycosaminoglycans of human trabecular meshwork undergo age-related changes, as demonstrated by our morphological, histochemical and morphometrical results.     

Clinical and serological associations of autoantibodies to GW bodies and a novel cytoplasmic autoantigen GW182

A novel autoantigen named GW182 was recently identified when the serum from a patient with a sensory ataxic polyneuropathy was used to immunoscreen a HeLa cDNA library. Unique features of the GW182 protein include 39 repeats of glycine (G) and tryptophan (W) residues, binding to a subset of messenger RNA and localization to unique structures within the cytoplasm that were designated GW bodies (GWBs). The goal of the present study was to identify the clinical features of patients with anti-GW182 antibodies and to characterize the B cell anti-GW182 response by defining the epitopes bound by human autoantibodies. The most common clinical diagnosis of patients with anti-GW182 antibodies was Sjögren’s syndrome followed by mixed motor/sensory neuropathy, and systemic lupus erythematosus. Of interest, 5 (28%), 9 (50%), and 3 (17%) of the 18 sera that react with GWBs had autoantibodies to the GW182 and the 52 kDa and 60 kDa SS-A/Ro autoantigens, respectively. Epitopes bound by the human autoantibodies were mapped to the GW-rich middle part of the protein, the non-GW rich region, and the C-terminus of GW182 protein. None of the GW182 epitopes had significant sequence similarities to other known proteins. GW182 represents a new category of ribonucleoprotein autoantigens.     

Hypoglycaemia in an inner-city accident and emergency department: a 12-month survey.

In a 12-month survey on the causes and frequency of hypoglycaemia presenting to an inner-city accident and emergency department, a total of 86 cases were recorded. A missed meal and/or alcohol ingestion accounted for most of the precipitating causes, being 52% and 21% respectively. As 49% of subjects presented with major clinical manifestations of hypoglycaemia (fit or coma), greater emphasis is required in the instruction on regularity of meal and caution with alcohol in high-risk groups such as the diabetic and also in non-diabetic groups.     

Management of extensive osteoradionecrosis of the mandible with radical resection and immediate microvascular reconstruction.

PURPOSE: Osteoradionecrosis (ORN) is a severe and devastating late complication of radiotherapy in patients with head and neck cancer. Management of ORN remains controversial and the current approach has been focused on debridement, systemic antibiotics, and eventually hyperbaric oxygen therapy for small and limited ORN. However, this conservative approach is ineffective in controlling extensive bone and soft-tissue necrosis. Microvascular composite flaps have been used in a variety of head and neck ablative surgeries but its use for the management of ORN has not been fully explored. MATERIALS AND METHODS: From 1999 to 2002, 5 patients with refractory ORN of the mandible underwent radical resection and reconstruction with immediate microvascular-free fibular composite flap. All patients had been treated initially with conservative procedures and hyperbaric oxygen therapy. RESULTS: All patients had initially successful vascularized reconstruction by clinical examination with minimal postoperative morbidity. One patient had complete flap loss at 20 days due to orocutaneous fistula and infection. CONCLUSIONS: Radical resection followed by microvascular composite flap reconstruction is a reliable procedure in the management of patients with extensive ORN of the mandible.     

Isolation of rat cardiac sarcoplasmic reticulum with improved Ca2+ uptake and ryanodine binding

The instability of the oxalate-supported Ca2+ uptake activity of rat cardiac sarcoplasmic reticulum (CSR) in ventricular homogenates most likely accounts for the low specific activity of the rate of oxalate-supported Ca2+ uptake in previously reported fractions of isolated rat CSR. We have found that CSR vesicles with improved Ca2+ transport capabilities can be isolated if 1 M KCl is used to stabilize the CSR activity and to allow the extraction of the CSR from the cellular debris. The average rate of Ca2+ uptake by the isolated rat CSR in the presence of 10 mM oxalate at 37 degrees C was 0.45 mumols/min-mg in the absence of CSR Ca2+ channel blockers and 0.87 mumols/min-mg in the presence of 10 microM ruthenium red. The Ca(2+)-dependent ATPase activity under the conditions of oxlate-supported uptake was 1.25 mumols/min-mg and 0.84 mumols/min-mg in the absence and presence of 10 microM ruthenium red, respectively. The rat CSR vesicles bound 3H-ryanodine with a Kd of 1.45 nM and a Bmax of 3.7 pmol mg. The level of phosphorylated intermediate was 0.30 nmol/mg. The values Bmax, EP and Ca(2+)-ATPase activity are from one-third to one-half of those previously reported for isolated canine CSR vesicles. These results suggest that the isolated rat CSR may be quite similar to dog CSR.     

Histochemical Demonstration of β-Glucuronidase Activity in Experimental Inflammation Produced by Croton Oil in Rats

The β-glucuronidase activity has been studied with histochemical methods in experimental inflammation produced by croton oil in rat skin. The enzyme activity increased progressively in the early phase of inflammation parallel to the local glycosaminoglycane and glycoprotein quantity, and it was still marked at the end of the sixth week. The activity was observed first of all within and in the neighbourhood of the macrophages and fibroblasts. The infiltrating granulocytes showed very slight or no identifiable activity. The role of the β-glucuronidase in the metabolic processes is discussed.     

Aldosterone excess: a rare non-nephrophathic cause of hypertension in type I diabetes.

The aetiology of hypertension in type 1 diabetes is commonly due to the presence of diabetic nephrology. A rare case of hypertension in a patient with type 1 diabetes and no proteinuria is reported, where the investigation of borderline hypokalaemia allowed us to make a diagnosis of hyperaldosteronism due to bilateral adrenocortical hyperplasia. Secondary causes of hypertension should always be considered in all diabetic patients, particularly in the absence of clinical proteinuria.     

Calcium absorption and intestinal calcium-binding protein: quantitative relationship.

The concentration of the vitamin D-induced calcium-binding protein (CaBP) and calcium absorption from the duodenum were investigated in chicks with an in vivo ligated-loop technique. The relation between CaBP and calcium absorption was dependent on a) source of vitamin D activity (either vitamin D3 or 1,25-dihydroxycholecalciferol); b) dosage of vitamin D3; c) time after administration of vitamin D3 to rachitic animals. To aid in the interpretation of these results, a phenomenological model was developed in which CaBP was viewed as being linearly related to a portion of calcium absorption. The model, when applied to the data, suggests that there is a "nonfunctional" pool of CaBP the size of which is determined by the vitamin D status of the animal. After correction for this nonfunctional pool, the proportionality between CaBP and calcium absorption is independent of the vitamin D status of the animal.