Treatment of burns and donor sites with human allogeneic keratinocytes grown on acellular pig dermis

The absence of a dermal component predisposes cultured epidermal sheets to instability, contractibility, and makes them difficult to handle. In order to overcome these drawbacks, we developed recombined human/pig skin (RHPS) composed of human keratinocytes cultured on cell-free pig dermis. The original intention to prepare a permanent skin substitute composed of xenodermis and autologous epidermis was not achieved, but it has been proved that RHPS can serve as an effective, ready to use keratinocyte delivery system when applied‘upside-down', i.e. with epidermal cells facing the wound surface. The keratinocyte layer establishes a direct contact with the wound bed, while the dermal layer mechanically protects the wound. Twenty deep dermal burns were grafted with RHPS: 13 (65%) healed completely in 4–14 days, three (15%) healed partially and four (20%) did not heal. Of five full thickness burn wounds only one healed after repeated RHPS grafting within 18 days. Thirty-one (100%) donor sites treated with any of the three forms of RHPS, subconfluent, confluent meshed or confluent unmeshed, healed within 6–8 days compared with 14–18 days in control sites. Seven donor sites (100%) of immunodeficient patients with prolonged wound healing epithelialized in 7–10 days under RHPS compared with 32–90 days in areas treated with tulle gras and dry gauze.     

Familial cases of Behcet''s disease

Seven families with Behcet's disease are presented. HLA-B5 tissue type was shown in the three families in whom lymphocyte microcytotoxicity tests were carried out. Genetic factors appear to be important in the pathogenesis of Behcet's disease.     

PAROXYSMAL TACHYCARDIA IN INFANCY AND CHILDHOOD II. Paroxysmal Ventricular Tachycardia and Fibrillation

A retrospective 3–20-years follow-up study of 1 infant and 10 children with paroxysmal ventricular tachycardia (8 cases) or fibrillation (3 cases) is presented. Additional heart disease has been observed in 60% (myocarditis 3 cases, cardiomyopathy 3 cases, congenital heart disease 1 case). Symptoms of tachycardia were: palpitation, tiredness, weakness, dyspnoea, precordial and abdominal pain. Syncopes were observed in 3 cases; 1 child had no symptoms. Tachycardia of hours to days' duration have been noted in 8 patients, 7 had tachycardia of repetitive type with a-v dissociation, one continuous tachycardia without any intervening sinus beats after the onset of tachycardia and with retrograde atrial activation. The remaining 3 children had brief malignant tachycardia, i.e. stress-provoked bursts of ventricular activity occasionally converting to ventricular fibrillation causing syncope. The diagnosis of brief malignant tachycardia had to be based on exercise ECG (2 cases) or long-term ECG-monitoring by telemetry (one case). One child with cardiomyopathy had died at the time of follow-up and the 3 patients with brief malignant tachycardia had experienced repeated life-threatening attacks—one of which had to be stopped by emergency d.c. countershock. The period of attacks ceased in 5 cases within 2 years after onset, in 1 patient, 9 years elapsed between first and second attack. Preventive treatment with betablocking agents proved beneficial in the 3 children with brief malignant tachycardia.     

Usefulness of Multichannel Holter ECG Recording in the Third Intercostal Space for Detecting Type 1 Brugada ECG: Comparison with Repeated 12-Lead ECGs

Introduction : Type 1 Brugada ECG is essential for the diagnosis of Brugada syndrome. We aimed to evaluate the usefulness of multichannel Holter ECG recording in the third intercostal space for detecting type 1 Brugada ECG.
Methods and Results : We enrolled 60 consecutive individuals with type 1 Brugada ECG and 31 individuals with type 2 or 3 Brugada ECG, in the presence or absence of Na+ channel blockers. All individuals underwent 12-lead ECGs recorded in the standard position and the third intercostal space at least 5 times every 3 months (4L-ECGs, 3L-ECGs, respectively) and multichannel Holter ECG. On multichannel Holter ECG, the precordial electrodes were attached at standard positions (4L-Holter) and the third intercostal space (3L-Holter) for leads V1 and V2. Among the 60 individuals, type 1 Brugada ECG in 4L-ECGs, 3L-ECGs, 4L-Holter, and 3L-Holter was detected in 15 (25%), 26 (43.3%), 23 (38.3%), and 33 individuals (55%), respectively, whereas detected in none of the 31 individuals. The documented duration of type 1 Brugada ECG on 3L-Holter was significantly longer than that on 4L-Holter (700 ± 467 vs 372 ± 422 min; P = 0.01, 3L-Holter vs 4L-Holter, respectively), and type 1 Brugada ECG was most frequently observed between 6 pm and 12 pm. Neither the presence nor the duration of the appearance of type 1 Brugada ECG differed significantly between symptomatic and asymptomatic individuals.
Conclusion : Multichannel Holter ECG recording in the third intercostal space is more sensitive and useful for the diagnosis of type 1 Brugada ECG than repeated 12-lead ECGs or multichannel Holter ECG in the standard position.     

A K-ras oncogene increases resistance to sulindac-induced apoptosis in rat enterocytes

BACKGROUND & AIMS: Mutations of c-K-ras occur commonly in colonic neoplasms. The aim of this study was to determine how c-K-ras mutations alter the responses to the chemopreventive agent sulindac. METHODS: The parental rat intestinal cell line IEC-18 and c-K-ras-transformed derivatives were treated with sulindac sulfide. Cell cycle distribution was determined by flow-cytometric analysis (fluorescence-activated cell sorter), apoptosis by DNA fragmentation (laddering), flow cytometry, and microscopy, and changes in gene expression by immunoblotting. RESULTS: Sulindac sulfide inhibited cell growth and induced apoptosis in a time- and dose-dependent manner more rapidly in and at lower concentrations in parental cells than ras-transformed cells. Expression of the sulindac sulfide arrested cells in G0/G1, but cells entered apoptosis throughout the cell cycle. Proapoptotic protein Bak was relatively high in untreated parental cells and increased markedly after sulindac sulfide but was low in untreated ras-transformed cells and did not increase after sulindac sulfide. Expression of other Bcl-2 family members was unchanged after sulindac sulfide. However, sulindac sulfide reduced levels of cyclin D1 protein and cyclin E- and cyclin D1- associated kinase activity. CONCLUSIONS: c-K-ras-transformed enterocytes are relatively resistant to sulindac sulfide-induced growth inhibition and apoptosis, which may result from specific reduction of bak expression. (Gastroenterology 1997 Dec;113(6):1892-900)     

Molecular imaging of dementia

Diagnosis and treatment strategies for dementia are based on the sensitive and specific detection of the incipient neuropathological characteristics, combined with emerging treatments that counteract molecular processes in its pathogenesis. Positron emission tomography (PET) is used for diverse clinical and basic studies on dementia with a wide range of radiotracers. Approaches to visualize amyloid deposition in human brains non‐invasively with PET depend on imaging agents reacting with amyloid fibrils. The most widely used tracer is [¹¹C]‐6‐OH‐BTA‐1, also known as Pittsburgh Compound‐B, which has a high affinity to amyloid β peptide (Aβ) aggregates. Some ¹⁸F‐labeled amyloid ligands with a longer radioactive half‐life have also been developed for broader clinical applications. In addition, there have been demonstrated advantages of tracers with high specific radioactivity in the sensitive detection of amyloid, which have indicated the significance of Aβ‐N3‐pyroglutamate as a new diagnostic and therapeutic target. Furthermore, beneficial outcomes of Aβ and tau immunization in humans and mouse models have highlighted crucial roles of immunocompetent glia in the protection of neurons against amyloid toxicities. The utility of PET with a radioligand for translocator protein as a biomarker for tau‐triggered toxicity, and as a complement to amyloid and tau imaging for diagnostic assessment of tauopathies with and without Aβ pathologies, has also been demonstrated. Meanwhile, brain cholinergic function can be estimated by measuring acetylcholinesterase activity in the brain with PET and radiolabeled acetylcholine analogues. It has been reported that patients with early Parkinson's disease exhibit a reduction in acetylcholinesterase activity in the cerebral cortex, and this decline is more profound in patients with Parkinson's disease with dementia and dementia with Lewy bodies than in patients with Parkinson's disease without dementia. The Alzheimer's Disease Neuroimaging Initiative was a multicentre research project conducted over 6 years that studied changes in cognition, brain structure, and biomarkers in healthy elderly controls and subjects with mild cognitive impairment and Alzheimer's disease. An international workgroup of the National Institute on Aging‐Alzheimer's Association has suggested that Alzheimer's disease would be optimally treated before significant cognitive impairment, defined as a ‘presymptomatic’ or ‘preclinical’ stage. Therefore, PET will be of technical importance for both clinical and basic research aimed at prodromal pathologies of Alzheimer's disease.     

Studies of muscarinic receptor reserve linked to phosphoinositide hydrolysis in parotid gland and cerebral cortex

Hydrolysis of inositol phospholipids caused by muscarinic agonists was studied in the guinea-pig parotid gland (PG) and cerebral cortex (CX). The present study describes the effect of two muscarinic agonists, carbachol and oxotremorine, on stimulation of phosphoinositide hydrolysis and on binding of [³H]NMS in the presence of the irreversible muscarinic antagonist benzilyl choline mustard (BCM). Carbachol and oxotremorine stimulated the formation of inositol phosphates in PG, pD₂(Carb) = 5.3 ± 0.1, pD₂(Oxo) = 5.9 ± 0.1 and in CX, pD₂(Carb) = 4.3 ± 0.2, pD₂(Oxo) = 5.8 ± 0.2. In the present study slices from both tissues have been exposed to 0.1 μM BCM for 2, 5 and 10 min. Treatment for 10 min caused a 75–85%, reduction in specific [³H]N-methyl scopolamine ([³H]NMS) binding sites in both PG and CX. Following 2 min BCM treatment of PG a marked decrease in pD₂ value of the carbachol-stimulated inositol phosphate formation was found. This effect was not found in CX. The results showed that a 30–40% reduction in binding sites shifted the carbachol concentration response curve to the right by one order of magnitude and reduced the oxotremorine-induced release of inositol phosphates by approximately 20%. In PG, the BCM-induced reduction of the carbachol-stimulated inositol phosphate formation was paralleled by the reduction in receptor binding sites. Similar treatment, but in CX, showed a lower reduction of the carbachol-stimulated inositol phosphate formation as compared to the reduction in receptor-binding sites. The results from the present study indicate that stimulation of phosphoinositide hydrolysis in PG involves a receptor reserve, mainly via stimulation of M₂-muscarinic receptors.     

Effect of Pyridoxal 5''-Phosphate on the Oxygen Affinity of Human Erythrocytes

Pyridoxal 5'-phosphate (PLP), an allosteric effector for the oxygenation of haemoglobin, was incorporated readily into erythrocytes and disappeared from them by simple passive diffusion. The disappearance of PLP from the cells was accelerated by the generation of 2,3-DPG in a medium of inosine, pyruvate and phosphate. The oxygen dissociation curve measured at an extracellular pH of 7.4 demonstrated that PLP incorporated into the cells also lowered the oxygen affinity and that PLP functionally compensated for a metabolically reduced 2,3-DPG. However, the dependency of the oxygen affinity on the intracellular PLP concentration showed a different pattern from the observed for 2,3-DPG. On the other hand, the lowering of intracellular pH by organic phosphates accumulated in the cells was much larger with PLP than with 2,3-DPG. The peculiar relationship between the oxygen affinity of erythrocytes and the intracellular PLP concentration is discussed in detail. The present study may offer a new prospect for the preservation of blood with a normal function.