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Braulke I, Zoll B, Hartmann H. Hereditary pancreatitis--a case report. ZEITSCHRIFT FUR GASTROENTEROLOGIE 1994; 32:645-6. [PMID: 7886974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A female patient with hereditary chronic pancreatitis is described. She presented initially at the age of 18 years with abdominal pain due to acute pancreatitis. Predisposing etiological factors were not recognized. During the ensuing years she had recurrent episodes of abdominal pain and chronic pancreatitis with extensive pancreatic calcifications was finally demonstrated. Six other family members within three generations were affected by chronic pancreatitis suggesting an autosomal dominant mode of transmission. None of the affected patients showed signs of diabetes mellitus, aminoaciduria or hyperparathyroidism.
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Pingel S, Hartmann H, Ramadori G. Essential mixed cryoglobulinemia (EMC) in a case of chronic hepatitis C--successful treatment with interferon alpha. ZEITSCHRIFT FUR GASTROENTEROLOGIE 1994; 32:584-8. [PMID: 7716994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chronic hepatitis C virus infection has previously been shown to be associated in some cases with an immunologic disorder called "Essential Mixed Cryoglobulinemia" (EMC). In this report a case of transfusion-associated chronic hepatitis C will be demonstrated. During patient's follow-up over a period of fifteen years the woman developed symptoms consistent with the clinical triad of EMC: general weakness, polyarthralgias and purpura. Laboratory chemical values support the presence of mixed cryoglobulins. Application of different therapeutic strategies revealed an improvement of both clinical and biochemical findings during interferon-alpha treatment. Results suggest that during chronic hepatitis C virus infection interferon-alpha therapy may represent the elective choice of treatment for typical symptoms of EMC.
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228
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Wallner I, Hartmann H, Ramadori G. [Current therapeutic strategies for hepatocellular carcinoma, 2]. LEBER, MAGEN, DARM 1994; 24:187-201. [PMID: 7968178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Therapeutic decisions depend on the tumor stage and the functional reserve of the tumor-free liver since most HCC are found in cirrhotic livers. Prospective randomized trials are not available, as is a uniform stage-adapted therapeutic concept. The only potentially curative therapy is surgical. Only 15-30% of patients are suitable for liver resection; localized but anatomically or functionally irresectable tumors can be treated by liver transplantation. Both methods have shown a high recurrence rate; controlled studies on adjuvant therapy are missing. Percutaneous ethanol injection therapy is an alternative in early stages resulting in survival rates comparable to surgical resection. More advanced tumors can be treated by transarterial chemoembolization using Lipiodol. Chemotherapy is little successful, the standard substance Adriamycin achieving remission rates of about 20%. To improve the results of chemotherapy, a combination of cytostatic agents with Lipiodol in non-metastasized tumors has been proposed. Among new therapeutic options such as treatment with cytokines, hormone antagonists, lipiodol or antibodies coupled with radioactivity no definite results have been published so far. Therefore, all patients with HCC should be treated in prospectively controlled, randomized studies.
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229
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Nolte W, Hartmann H, Ramadori G. [Portal hypertension--pathophysiology and therapeutic approaches]. ZEITSCHRIFT FUR GASTROENTEROLOGIE 1994; 32:447-59. [PMID: 7975788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The following review article describes pathophysiological aspects of portal hypertension in its first part, especially the topographic variety of the vascular collateral system creating the danger of variceal bleeding. The second part discusses different forms of therapy including pharmaco- and sclerotherapy as well as operative and interventional procedures. Beta-blocker-therapy preferentially serves for the primary and secondary prevention of variceal bleeding. Sclerotherapy appears as the dominant therapeutic tool for the management of acute variceal bleeding. New chances of therapy include variceal banding and the implantation of a transjugular intrahepatic portosystemic stent-shunt (TIPSS). Operative procedure loose their significance more and more by the wide-spread use of sclerotherapy and the chance of a definite therapy of portal hypertension (liver transplantation) and the use of nonoperative interventional procedure (TIPSS or TIPS) which are still under clinical investigation.
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Wallner I, Hartmann H, Ramadori G. [Current therapeutic strategies in hepatocellular carcinoma, Part 1]. LEBER, MAGEN, DARM 1994; 24:150, 153-4. [PMID: 7934608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hepatocellular carcinoma (HCC) is the most frequent primary malignancy of the liver, most prevalent in Asia and Africa but also showing a rising incidence worldwide. Chronic hepatitis B and C virus infection is the most important risk factor for HCC. More than half of the patients suffer from underlying liver cirrhosis. The prognosis is determined by tumor stage and residual capacity of the liver, the median survival being 0.9 to 12.8 months for patients receiving no specific treatment. In the East, early detection has been improved by screening programs which seem to be less valuable in the Western world.
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Hartmann H, Samuels MP, Noyes JP, Goldstraw P, Brookfield DS, Southall DP. A case of congenital chylothorax treated by pleuroperitoneal drainage. J Perinatol 1994; 14:313-5. [PMID: 7965229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A congenital chylothorax that necessitated recurrent pleural taps was successfully treated by a pleuroperitoneal shunt that was inserted when the infant was 28 days old. Further thoracentesis was avoided and failure to thrive was overcome.
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Oellerich M, Schütz E, Polzien F, Ringe B, Armstrong VW, Hartmann H, Burdelski M. Influence of gender on the monoethylglycinexylidide test in normal subjects and liver donors. Ther Drug Monit 1994; 16:225-31. [PMID: 8085276 DOI: 10.1097/00007691-199406000-00001] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The objective of this study was to investigate the effect of gender on monoethylglycinexylidide (MEGX) formation in normal subjects and cadaveric liver donors. The study included 92 male and female healthy volunteers < 45 years of age and 98 age- and sex-matched liver donors from a previous study, whose livers were used for transplantation. Women < 45 years not taking contraceptives showed significantly lower MEGX concentrations 30 min after lidocaine administration than men [median (16-84th percentile)]: 59 micrograms/L (41-70 micrograms/L) versus 81 micrograms/L (58-98 micrograms/L)]. The lowest MEGX 30 min values were observed in women taking contraceptives: 39 micrograms/L (25-48 micrograms/L). Intraindividual variability of serial MEGX tests was moderate (median: 17.8%, n = 8) when measured in female subjects taking no contraceptives and males. Cadaveric liver donors showed significantly higher MEGX 15 and 30 min values compared with normal subjects (p < or = 0.0001). There was no statistically significant difference between MEGX values obtained in male and female cadaveric donors. The urinary excretion of MEGX was similar in male and female normal subjects. Our results suggest that sex-related differences in MEGX formation as well as the influence of contraceptives have to be taken into account when test results from living related liver donors and patients with less advanced chronic liver disease are evaluated. In cadaveric liver donors, however, sex-related differences do not affect MEGX formation.
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Utts J, Cook TD, Cooper H, Cordray DS, Hartmann H, Hedges LV, Light RJ, Louis TA, Mosteller F. Meta-Analysis for Explanation: A Casebook. J Am Stat Assoc 1994. [DOI: 10.2307/2290883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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234
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Hartmann H, Eckert A, Müller WE. Apolipoprotein E and cholesterol affect neuronal calcium signalling: the possible relationship to beta-amyloid neurotoxicity. Biochem Biophys Res Commun 1994; 200:1185-92. [PMID: 8185566 DOI: 10.1006/bbrc.1994.1576] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Besides the neurotoxic properties of beta-amyloid (beta A4), apolipoprotein E polymorphism seems to play an important role in the pathogenesis of sporadic Alzheimer's disease (AD). The calcium amplifying effect of beta A25-35 (the neurotoxic sequence of beta A4) in dissociated mouse brain neurons and human lymphocytes was nearly abolished by cholesterol (100-500 mumol/l). This effect may be related to the membrane stabilizing properties of cholesterol which could be confirmed by measurements of membrane fluidity. ApoE did not affect the Ca2+ amplifying effect of beta A25-35, but amplified the neuronal Ca2+ response significantly in a very low concentration (100nmol/l). The findings suggest a possible link between AD pathology and ApoE polymorphism by the calcium amplifying effect of ApoE itself as well as by the modulation of beta A4 neurotoxicity by cholesterol.
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Reder S, Hartmann H. [Diagnostic and pathophysiological aspects of the determination of kidney function in animals]. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1994; 41:253-67. [PMID: 7975970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Early diagnosis of loss in renal function (< 60-70%) is not possible either by resorting to the parameters of plasma urea and creatinine concentrations (responsive to functional loss by > 75% or by reference to urine concentration capacity (urine density: sensitive to concentrations > 60%). However, clearance techniques for determination of the glomerular filtration rate (GFR) have proved suitable for quantitative assessment of renal function. Endogenous creatinine clearance is one of the most common clinical approaches in GFR determination. Criticism of results obtainable from endogenous creatinine clearance appears to be justified by pharmacokinetic aspects of creatinine as an indicator, as well as by some of its analytical peculiarities. The tediousness of the procedure is another counterproductive aspect pertaining to large-scale use of endogenous creatinine clearance in veterinary medicine. Total blood-plasma clearance of exogenous creatinine (T-Clexo.Creatinine) would provide vets with an accurate (diagnostic validity) and practical method for carrying out clinical kidney-function diagnostics. However, more research on a number of related issues will be required before the general introduction of the procedure.
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Hartmann H, Jawad MH, Noyes J, Samuels MP, Southall DP. Negative extrathoracic pressure ventilation in central hypoventilation syndrome. Arch Dis Child 1994; 70:418-23. [PMID: 8017965 PMCID: PMC1029832 DOI: 10.1136/adc.70.5.418] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Nine patients with central hypoventilation syndrome (CHS) were treated with negative extrathoracic pressure ventilation (VNEP). Treatment with VNEP was started between 20 days and 57 months of age, which was two days to 47 months after diagnosis. The equipment to provide VNEP utilised a new system with a latex neck seal and Perspex chamber allowing easy access to the child. Seven patients are managed with VNEP at home by their parents. They did not have a tracheostomy when VNEP was started at ages of 22, 24, 31, 38, and 75 days, 5 and 57 months. They have continued to be successfully managed with VNEP and without tracheostomy. Short periods of intubation and positive pressure ventilation were required on 10 occasions (median duration 7 days, range 4 to 21 days) in four subjects during respiratory tract infections. Three patients required periods of continuous positive airway pressure (CPAP) via a nasal mask or a nasopharyngeal airway during sleep to overcome upper airway obstruction. In three patients the hypoventilation improved and two of these do not require regular ventilatory support at 1.3 and 3.4 years of age. Six of these seven patients are developing normally. In two patients with long term tracheostomies, VNEP could not be established at an age of 29 and 52 months because of tracheal obstruction after temporary removal of their tracheostomy cannula. VNEP is an effective, non-invasive, treatment in infants with CHS if initiated before tracheostomy. It may improve the children's quality of life during the daytime. If upper airway obstruction is a problem in the first year of life, it may be combined with nasal mask CPAP.
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237
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Flegel T, Hartmann H. [Evaluation of hypoxic conditions in calves using the erythrocyte density test (EDT)]. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1994; 41:215-28. [PMID: 7941838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The erythrocyte density separation test (EDT) divides the red blood cells into two groups: younger (less dense) and older (more dense) erythrocytes. Using this test enables veterinarians to assess the erythropoiesis in calves on the basis of the percentage of less dense (younger) red blood cells. Anemic calves, as well as those with pneumonic infections show higher proportions of less dense red blood cells in the EDT than healthy ones. This testing procedure makes it possible to estimate the effects of an oxygen deficiency condition, such as hypoxemia, anemia, shock etc. on the peripheral tissues. So the EDT represents a valuable complement to existing hematological laboratory methods. Carrying out the EDT is very simple and suitable in routine clinical testing.
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Schwörer H, Hartmann H, Ramadori G. Treatment of chronic cryptosporidiosis-induced diarrhea with a serotonin receptor antagonist. Am J Gastroenterol 1994; 89:458. [PMID: 8122672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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239
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Reder S, Hartmann H. Diagnostische und pathophysiologische Aspekte der Nierenfunktionsbestimmung bei Tieren. ACTA ACUST UNITED AC 1994. [DOI: 10.1111/j.1439-0442.1994.tb00093.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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240
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Hartmann H, Eckert A, Förstl H, Müller WE. Similar age-related changes of free intracellular calcium in lymphocytes and central neurons: effects of Alzheimer's disease. Eur Arch Psychiatry Clin Neurosci 1994; 243:218-23. [PMID: 8172934 DOI: 10.1007/bf02191577] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Several studies suggest that alterations of cytosolic free calcium concentration ([Ca2+]i) are involved in the pathophysiology of aging and Alzheimer's disease (AD). However, only few data are presently available giving detailed information about specific characteristics of age-related or AD-specific changes in cellular Ca(2+)-homeostasis. To allow a comprehensive evaluation of age-related changes in [Ca2+]i we performed parallel investigations in central mouse brain cells and mouse spleen lymphocytes of young and aged animals and also in human lymphocytes and granulocytes of young and aged donors and additionally of AD patients. In aged animals, basal [Ca2+]i was decreased in brain cells but increased in spleen lymphocytes. No age-related alterations in baseline [Ca2+]i was found in human lymphocytes or granulocytes. However, comparison of activation-induced rise in [Ca2+]i revealed parallel age-related changes in the different cell-types investigated. The increase in [Ca2+]i after depolarization of mouse brain cells with KCl and after stimulation of mouse lymphocytes with phytohaemagglutinin (PHA) was significantly impaired in aged animals. Moreover, activation of human lymphocytes with PHA also revealed a reduced increase in [Ca2+]i in cells of aged donors. In lymphocytes of AD-patients there was a tendency to higher basal [Ca2+]i compared to their aged matched controls, but no specific alterations in [Ca2+]i could be found after stimulation with PHA. Also no age-related or AD-specific changes were found in granulocytes after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP).(ABSTRACT TRUNCATED AT 250 WORDS)
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Eckert A, Hartmann H, Förstl H, Müller WE. Alterations of intracellular calcium regulation during aging and Alzheimer's disease in nonneuronal cells. Life Sci 1994; 55:2019-29. [PMID: 7997061 DOI: 10.1016/0024-3205(94)00382-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Because of its function as an intracellular messenger in many cells, calcium plays an important role in signal transduction. Changes in intracellular free calcium concentration occur in central neurons during aging and Alzheimer's disease (AD). It is possible that similar changes in peripheral cells could mirror or, at least parallel, similar abnormalities in the brain. Assuming that manifestations of the aging process and AD are also present outside the central nervous system, nonneuronal tissues like lymphocytes could be used to search directly for abnormalities in cellular calcium regulation in man. Consistent with observations of reduced depolarization-induced Ca2+ rises in dissociated neurons of aged mice, corresponding age-related changes of reduced mitogen-induced Ca2+ responses were observed both in mouse lymphocytes and, more importantly, in circulating human lymphocytes. With respect to AD, Ca2+ responses after stimulation were unaltered (compared to normal controls). In addition, freshly prepared human lymphocytes showed elevated mitogen-induced Ca2+ responses after exposure to beta-amyloid, the main component of senile plaques in AD. These findings again parallel our observations that this peptide amplifies the K(+)-induced Ca2+ rise in acutely dissociated mouse brain cells. Thus, the lymphocyte seems to be a valuable model to study the effects of beta-amyloid in man. In a preliminary study with AD-patients, sensitivity of the lymphocytes to beta-amyloid's effects on Ca2+ rise was reduced, an observation which was entirely unexpected. Nevertheless, such studies indicate lymphocytes may represent a promising candidate for a peripheral marker of AD and can contribute to the understanding of the disease process.
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Hartmann H, Eckert A, Müller WE. Disturbances of the neuronal calcium homeostasis in the aging nervous system. Life Sci 1994; 55:2011-8. [PMID: 7997060 DOI: 10.1016/0024-3205(94)00381-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Maintenance of the cellular calcium homeostasis plays an important role for neuronal cell function and interneuronal cell to cell communication. Therefore, alterations of the neuronal Ca2+ homeostasis may play a crucial role for brain aging in general and for age-related deficits in cognitive functions particularly. Numerous studies indicate various disturbances of the Ca2+ homeostasis on different levels like Ca2+ channel properties, 45Ca2+ uptake, or Ca2+ binding proteins. Investigations on alterations of the free intracellular calcium concentration ([Ca2+]i) in presynaptic synaptosomal preparations led to inconsistent results reporting increased or unchanged [Ca2+]i in aged animals. Postsynaptic alterations of [Ca2+]i have been investigated mainly indirectly by electrophysiological methods and revealed prolonged Ca(2+)-dependent afterhyperpolarization or prolonged Ca2+ spike duration. By using acutely dissociated mouse brain cells it was possible for the first time to evaluate age-dependent alterations of postsynaptic [Ca2+]i directly. In neurons of aged mice basal [Ca2+]i was reduced and depolarization-induced rise in [Ca2+]i was also reduced, probably as a result of increased activation of Ca(2+)-dependent mechanisms terminating Ca(2+)-influx. Depolarization-induced, Ca(2+)-mediated inositolphosphate accumulation was also increased in aged animals. This leads to the conclusion that Ca(2+)-dependent intracellular processes become more sensitive during aging. Investigations about the effect of beta-amyloid on the Ca2+ homeostasis in the same system revealed a small but consistent destabilizating effect of this peptide on K(+)-induced rise in [Ca2+]i which may result in chronically increased neuronal vulnerability. Together with increased Ca2+ sensitivity during aging this might be one of the reasons for the increasing prevalence of Alzheimer's disease (AD) with aging.
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Stoll S, Hartmann H, Cohen SA, Müller WE. The potent free radical scavenger alpha-lipoic acid improves memory in aged mice: putative relationship to NMDA receptor deficits. Pharmacol Biochem Behav 1993; 46:799-805. [PMID: 8309958 DOI: 10.1016/0091-3057(93)90204-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
alpha-Lipoic acid (alpha-LA) improved longer-term memory of aged female NMRI mice in the habituation in the open field test at a dose of 100 mg/kg body weight for 15 days. In a separate experiment, no such effect could be found for young mice. alpha-LA alleviated age-related NMDA receptor deficits (Bmax) without changing muscarinic, benzodiazepine, and alpha 2-adrenergic receptor deficits in aged mice. The carbachol-stimulated accumulation of inositol monophosphates was not changed by the treatment with alpha-LA. These results give tentative support to the hypothesis that alpha-LA improves memory in aged mice, probably by a partial compensation of NMDA receptor deficits. Possible modes of action of alpha-LA based on its free radical scavenger properties are discussed in relation to the membrane hypothesis of aging.
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Hartmann H, Lübbers B, Casaretto M, Bautsch W, Klos A, Köhl J. Rapid quantification of C3a and C5a using a combination of chromatographic and immunoassay procedures. J Immunol Methods 1993; 166:35-44. [PMID: 7693822 DOI: 10.1016/0022-1759(93)90326-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Monoclonal antibodies were isolated which reacted specifically with the complement cleavage products C3a, C3adR, C5a, and C5adR but not with the parent molecules C3 or C5. In both cases the mAbs showed a higher affinity towards the desArg forms. These mAbs were used as capture antibodies in immunoassays for C3a/C3adR and C5a/C5adR. The immunoassays are based on the ABICAP technology which ensures for a rapid measurement. Due to the large binding capacity and the very short diffusion pathways in the gel-matrix the binding equilibrium between capture antibodies and the antigen is reached whilst the sample is flowing through the column. Therefore this test represents an endpoint assay offering the possibility of using a single calibration curve for a large number of measurements. With the C3adR assay concentrations down to 16 ng/ml C3adR can be detected. The lower detection limit of the C5adR assay is 1 ng/ml C5adR. The tests for C3a/C3adR, and C5a/C5adR can be performed in 20 to 25 min and this rapid processing of plasma samples should permit the application of these parameters for diagnostic purposes and patient management.
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Poets CF, Samuels MP, Noyes JP, Hewertson J, Hartmann H, Holder A, Southall DP. Home event recordings of oxygenation, breathing movements, and heart rate and rhythm in infants with recurrent life-threatening events. J Pediatr 1993; 123:693-701. [PMID: 8229476 DOI: 10.1016/s0022-3476(05)80842-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
For an evaluation of the usefulness of event recording in identifying mechanisms for apparent life-threatening events, 94 infants (median age, 3.1 months; range, 0.5 to 12 months) with a history of two or more apparent life-threatening events of hitherto unknown cause underwent event recording of transcutaneous oxygen pressure, arterial oxygen saturation, (not recorded in all patients), breathing movements, pulse waveforms, electrocardiogram, and instantaneous heart rate. Recordings were triggered by a fall in transcutaneous oxygen pressure to less than 20 mm Hg. During a median duration of event recording of 1.3 months (0.1 to 10 months), 52 events were recorded in 34 patients; 7 of the events had to be excluded because of uninterpretable signals. The following mechanisms were identified in the remaining 30 patients (45 events): a sudden change in skin perfusion but without hypoxemia (6 in 5 patients), hypoxemia induced by an epileptic seizure (6 in 5 patients), hypoxemia induced by suffocation by a parent (4 in 4 patients), and parental fabrication of events and medical history (7 in 6 patients). In the remaining 22 events in 12 patients, the precise mechanism of events could not be identified. Analysis of these as-yet-unexplained events showed prolonged abnormal hypoxemia (a fall in transcutaneous oxygen pressure to between 4 and 18 mm Hg and a fall in arterial oxygen saturation to 5% to 75%), lasting for 40 to 500 seconds in all. Only five of these events involved prolonged (> 20 seconds) apneic pauses, and only four an episode of bradycardia (heart rate < 80 or 60 beats/min). Thus event recording identified various mechanisms of apparent life-threatening events. In the events that remained unexplained, prolonged apneic pauses or episodes of bradycardia were found in only a minority. The identification of hypoxemia therefore may be more relevant to the early detection of these events than the identification of apnea or bradycardia or both. The relevance of these findings with regard to sudden infant death syndrome remains to be determined.
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Haus U, Trommler P, Fisher PR, Hartmann H, Lottspeich F, Noegel AA, Schleicher M. The heat shock cognate protein from Dictyostelium affects actin polymerization through interaction with the actin-binding protein cap32/34. EMBO J 1993; 12:3763-71. [PMID: 8404847 PMCID: PMC413658 DOI: 10.1002/j.1460-2075.1993.tb06054.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
During isolation of the F-actin capping protein cap32/34 from Dictyostelium discoideum, a 70 kDa protein was copurified which by cloning and sequencing was identified as a heat shock cognate protein (hsc70). This protein exhibited a specific and MgATP-dependent interaction with the heterodimeric capping protein. To investigate the protein-protein interaction in vitro, we expressed all three polypeptides separately in Escherichia coli and performed reconstitution experiments of complete or truncated hsc70 with the 32 and 34 kDa subunits of the capping protein. Viscosity measurements and studies on the polymerization kinetics of pyrene-labeled actin showed that hsc70 increased the capping activity of cap32/34 up to 10-fold, whereas hsc70 alone had no effect on actin polymerization. In addition, hsc70 acted as a molecular chaperone by stimulating the refolding of the denatured 32 and 34 kDa subunits of the capping protein. To study the interaction of the two domains of hsc70 with cap32/34, the N-terminal 42 kDa ATPase region and the C-terminal 30 kDa tail of hsc70 were expressed separately in E. coli. The 32 and 34 kDa subunits were capable of associating with both domains of hsc70. The ATPase domain of hsc70, which is structurally related to actin, proved to be responsible for the increased capping activity of cap32/34, whereas the C-terminal tail of hsc70 was involved in folding of the subunits of cap32/34. Our data indicate a novel linkage between 70 kDa heat shock proteins and the actin cytoskeleton.(ABSTRACT TRUNCATED AT 250 WORDS)
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Hartmann H, Müller WE. Age-related changes in receptor-mediated and depolarization-induced phosphatidylinositol turnover in mouse brain. Brain Res 1993; 622:86-92. [PMID: 8242388 DOI: 10.1016/0006-8993(93)90805-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of aging on receptor- and G-protein-activated and on depolarization-induced phosphoinositide (PI) hydrolysis was examined in mechanically dissociated neurons from female NMRI mice. Additionally, age-dependent changes in Ca2+ homeostasis, i.e. changes in basal intracellular calcium ([Ca2+]i) and in depolarization-induced rise in [Ca2+]i were investigated. No age-related differences in PI hydrolysis were found after stimulation of muscarinic cholinergic, alpha 1, serotonin and quisqualate receptors coupled to the phosphoinositide-phospholipase C (PI-PLC) system. PI hydrolysis following stimulation with AMPA ((RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) revealed a significantly increased response in aged animals. Activation of G-proteins with NaF also induced a higher inositol monophosphate (InsP1) accumulation in aged mice. Moreover, InsP1 accumulation due to PLC activation by increased [Ca2+]i after depolarization with KCl was significantly increased in neurons from aged animals. Investigations about age-related changes in Ca2+ homeostasis revealed lower basal [Ca2+]i and lower rise in [Ca2+]i after depolarization with KCl. The data indicate that receptor-mediated and depolarization-induced PI hydrolysis are differentially affected by aging. Decreased availability of [Ca2+]i in aged animals may enhance the sensitivity of Ca(2+)-activated mechanisms. This may explain increased KCl- and AMPA-induced InsP1 accumulation whereas receptor-coupled PLC activation is less affected.
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Eckert A, Hartmann H, Müller WE. beta-Amyloid protein enhances the mitogen-induced calcium response in circulating human lymphocytes. FEBS Lett 1993; 330:49-52. [PMID: 8370457 DOI: 10.1016/0014-5793(93)80917-j] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The role of beta-amyloid in Alzheimer's disease and its cellular mechanism of action on neurons are still unclear. There is growing evidence that beta-amyloid or its fragment, 25-35, influence neuronal calcium regulation. To investigate the effects of beta-amyloid on calcium homeostasis in man we used peripheral human lymphocytes as a model system for central neurons. beta-Amyloid fragment 25-35 exposed to lymphocytes for 60 s elevates the phytohemagglutinin (PHA)-induced Ca2+ rise in a dose-dependent manner. Small effects were already seen at concentrations as low as 50 nmol/l. Similar effects were also observed with fragment 1-40, whereas fragments 1-28 or 12-28 did not affect the Ca2+ response after PHA stimulation. Our findings support the hypothesis of an enhanced calcium response as a general feature of beta-amyloid's neurotoxicity. The lymphocyte seems to be a valuable model to study this effect in man.
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Henschke M, Hartmann H. 102. Auslegung kontinuierlich betriebener liegender Flüssig/Flüssig-Abscheider anhand diskontinuierlicher Absetzversuche. CHEM-ING-TECH 1993. [DOI: 10.1002/cite.3306509104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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