Biomedical subjects
Publications and source records attributed to P Barth.
A non Hodgkin's lymphoma strictly located in the bone marrow, was discovered in a patient presenting with asymetric muscle weakness of upper and lower limbs. Both the lymphoma and the neurological syndrome were successfully treated with chemotherapy.
Microencapsulation of tissues is an alternative to postoperative immunosuppression in transplantation. In 1994 iso-, allo- and xenotransplantation of microencapsulated parathyroid tissue was achieved in vivo. However, continued analysis of the coating substance (an alginate) determined mitogenic properties. Here, we report on the in vitro and in vivo function of parathyroid tissue microencapsulated with a novel amitogenic alginate suitable for use in humans. To assess in vitro function, parathyroid tissue encapsulated with mitogenic and amitogenic alginate was exposed to rising concentrations of calcium. For in vivo experiments, it was isotransplanted into parathyroidectomized rats. PTH release into medium and PTH serum levels as well as calcium levels of recipient rats were analyzed and compared to native (non-microencapsulated) tissue and empty capsules, respectively. In vivo, transplants were excised and subjected to histologic examination six months after trans-plantation. In vitro, parathyroid tissue encapsulated with amitogenic alginate releases approximately half of the PTH of the native tissue, not different from tissue encapsulated with the mitogenic alginate. In vivo, the novel alginate preserved parathyroid function similar to that of native tissue over the six month period resulting in complete reversal of hypoparathyroidism. Correspondingly, histologic examination revealed vital parathyroid tissue in intact microcapsules. By establishing in vitro function and successful long-term transplantation, we have documented the principle of microencapsulation of parathyroid tissue to be effective also with the novel amitogenic alginate, which is suitable for clinical use.
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The magic-echo phase-encoding solid imaging (MEPSI) sequence is based on the magic-echo pulse sequence for the refocusing of the dipolar interaction and on pure phase-encoding for spatial resolution in all dimensions. MEPSI has many advantages; however, as a consequence of pure phase-encoding, it is very time-consuming. In the following, two strategies are proposed to decrease the time necessary for the acquisition of an image by a factor of 2 per dimension.
Relaxation-weighted NMR imaging is a powerful tool for the investigation of aging processes in rubber networks, in particular if it is combined with a theoretical description to relate the NMR data with suitable parameters of the material. Following this concept, spin-spin relaxation decays in rubber samples, consisting of differently aged pieces of natural rubber have been acquired in a spatially resolved experiment. The data were evaluated using a dynamical model and transformed into images of those material properties, which are affected by the aging process. Images representing the crosslink density and the correlation times, which characterize the polymer chain dynamics, have been calculated. The differently aged rubber pieces can be easily discriminated in such material property (MAP) images.
Three cases of malignant clear cell carcinoma of the gallbladder were studied immunohistochemically with a broad panel of antibodies, especially cytokeratins, in order to better characterize their histogenesis. The advantage of immunohistochemistry in the differential diagnosis between clear cell carcinoma of the gallbladder and other clear cell carcinomas metastatic to the gallbladder such as renal cell carcinoma is discussed.
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To study the effects of nitrogen dioxide (NO2) inhalation on lung lavage surfactant components as markers of an altered surfactant metabolism in type II pneumocytes, rats were exposed to atmospheres with increasing NO2 concentrations (0.8, 5.0, and 10.0 ppm) over 1 and 3 days. After exposure lung lavage was performed and surfactant components as well as lavageable cells analyzed. An increased number of total lavage cells was found with increasing concentration and duration of NO2 exposure. Cell distribution showed an elevation in the number of granulocytes and lymphocytes whereas the number of macrophages was diminished. The amount of total lavage protein revealed an increase related to NO2 concentration and duration. Also the content of lavage phospholipid was increased, with a decreased portion of phosphatidylcholine (PC). Further analyses of PC showed a diminished composition of saturated fatty acids but an elevated content of the unsaturated portion. Functional studies on surfactant phospholipid extracts exhibited comparable values for the surface tension at equilibrium, as well as for the maximal and minimal surface tension of animals exposed to 0.8 ppm NO2 and controls. Higher NO2 concentrations (5 and 10 ppm) resulted in increased values for surface tension compared to controls. This was also observed with purified surfactant that was obtained from controls and from NO2-exposed rats. These experiments show that in vitro exposure of purified surfactant to NO2 atmospheres was more effective than exposure in vivo. When the structure of the surfactant proteins A was studied it was found not to be altered by the NO2. The data clearly demonstrate that NO2 inhalation impaired function of surfactant components that may be used as markers of altered surfactant metabolism.
With rapid air travel, so-called parasitic infections are becoming more important in northern hemisphere and temperate climates. Parasitic disease is usually taken to imply infections caused by protozoa and helminths. The most important helminthic infections in man and with world-wide incidence are schistosomiasis, hookworm, and filariasis. We report the clinico-pathological findings of two patients with filarial infection of soft tissue and lymphatic nodes.
Eosinophilic cystitis is an unusual bladder lesion of unclear etiology first described in 1960. It usually causes irritative voiding symptoms and hematuria and in its rare tumor-like appearance the disease may mimic an invasive bladder neoplasm. In the report herein, a case of an 11-year-old boy with a tumor-forming eosinophilic cystitis is presented which was mistaken for an infiltrative vesical malignancy until the histopathological study was completed. The principal clinical findings, differential diagnosis, etiology, pathogenesis and treatment modalities of this inflammatory disease are discussed.
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We report on a 52-year-old patient with acute myeloid leukemia. After induction chemotherapy, routine ultrasound displayed a round focal hyperechoic intrasplenic lesion. Tumor was primarily misdiagnosed for splenic hemangioma. Diagnosis of spontaneous progredient splenic rupture was made by color-coded Doppler sonography, sonographic follow-up examinations and confirmed by splenectomy for final treatment. No trauma was found.
The complete sequence of pig lens aldose reductase (EC 1.1.1.21), a member of the nicotinamide coenzyme-dependent aldo-keto reductase super family, was determined by the combined use of data obtained from Edman degradation, fast-atom-bombardment mass spectrometry and electrospray mass spectrometry. The N-terminal residue of human and pig aldose reductase was shown to be acetylated. The assignment of a disulfide bridge (Cys298-Cys303) was obtained by mass spectrometry. Electrospray mass spectrometry has been used for molecular mass measurement of human muscle (35758 +/- 7 Da) and pig lens (35778 +/- 3Da) aldose reductase; using mild ionization conditions, it has also been used to study the reversible interaction involved in a non-covalent complex with NADP+ (36527 +/- 4Da). An alkylating analog of NADP+ (3-chloroacetylpyridine-adenine dinucleotide phosphate) was used as an irreversible inhibitor to investigate the NADP binding site and the mass of the covalent complex was measured (36521 +/- 3 Da).
Oxygen radicals and oxygen radical mediators derived from activated granulocytes are important components in the development of acute lung injury, namely the adult respiratory distress syndrome ARDS. N-acetylcysteine (NAC) is one important substance for endogenous production of reduced glutathion, which is known to be an intra- and extracellular reducing agent also found in lung tissue. We evaluated the effect of exogenous NAC on the endotoxin induced development and course of ARDS in rats. ARDS-like injury was induced in rats via intraperitoneal injection of Salmonella enteritidis endotoxin 30 mg/kg body weight. NAC or solvent was injected intraperitoneally 30 min prior to, at the time of and 30 min after injection of endotoxin respectively with 150 mg/kg body weight each dose. Endotoxin injection in rats resulted in 80% mortality within 72 hours, increased lung wet weight, severe ultrastructural lung damage as measured by histological methods. In isolated, ventilated, with physiological salt solution perfused rat lungs vasocontractility was severely blunted, lung albumin leakage was increased, thromboxane B2 (TXB2) and 6-keto-prostaglandin-F1 alpha (6-keto-PGF1 alpha) perfusate levels were increased. NAC treatment significantly improved survival of endotoxin treated rats, ameliorated structural lung damage, diminished lung wet weight and lung albumin leakage, lowered lung perfusate TXB2 and 6-keto-PGF1 alpha levels and slightly improved vasocontractility in isolated perfused lungs. Therefore, NAC significantly ameliorates ARDS-like lung injury in rats, when given in vivo.
A 16-year-old boy presented with a left anterothalamic lesion secondary to an extradural hematoma. A few months later, a right hemidystonia developed. The dystonic posture, which predominated in the right hand, was not associated with any motor deficit or sensory loss. Superficial sensory stimulation of the right palm and forearm and proprioceptive stimuli induced by passive movements of the right thumb decreased the dystonic posture. Electrical stimulation of the left ventroposterolateral nucleus of the thalamus induced a dramatic improvement in the dystonic postures and movement of the upper right limb. This finding suggests that the role of tactile and proprioceptive stimulation should be analyzed in patients presenting with a symptomatic hemidystonia. When such sensory stimulation is effective, thalamic stimulation may be tried in patients whose condition is incapacitating.
Various drugs have been shown to stimulate surfactant phospholipid metabolism. Particularly beta-adrenergic agonists play an important role under physiologic conditions. For the first time we have studied whether nitrogen dioxide (NO2) inhalation alters beta-adrenergic regulation of surfactant phospholipid metabolism in the model of the isolated lung. Rats were continuously exposed in vivo to a 5 ppm NO2-containing atmosphere for 48 hr. The lungs were isolated and perfused in presence of the beta-adrenergic agonist dopexamine and surfactant metabolism was studied in three lung compartments: (1) lung lavage, (2) lung tissue, and (3) lavagable free alveolar cells. We found that (1) in normal rat lungs dopexamine increased the incorporation of palmitate and choline from the perfusate into lung lavage phospholipids. In nitrogen dioxide exposed rat lungs beta-adrenergic stimulation did not cause an increase in precursor incorporation. No significant difference in unstimulated precursor incorporation was found for normal and NO2-exposed rat lungs. (2) Lung tissue from rats exposed to NO2 showed a decreased precursor incorporation into disaturated phosphatidylcholine due to an augmented cellular pool size. (3) Lavagable alveolar cells showed an increased palmitate uptake after nitrogen dioxide inhalation and by beta-adrenergic stimulation. From these data we conclude that nitrogen dioxide inhalation impairs the beta-adrenergic regulation of surfactant phospholipid metabolism. Moreover these data underline the importance of beta-adrenergic agonists in surfactant metabolism.
Recent data revealed the existence of specific receptors for glucagon-like peptide-1(7-36)amide (GLP-1) on rat lung membranes. Utilizing slide-mount autoradiography of fresh frozen lung tissue sections, we have localized binding sites for GLP-1 on mucous glands in the trachea and on vascular smooth muscle of the pulmonary artery. When tracheas were incubated in a modified Ussing chamber, the addition of GLP-1 to the submucosal side increased 35S-sulfate-labeled macromolecule secretion (191 +/- 12% above basal, P < 0.005). The optimal secretory response elicited by GLP-1 was approximately 23% of the maximal secretory response after a maximal acetylcholine stimulation. Other proglucagon-derived peptides such as glucagon, oxyntomodulin, and GLP-2 had no effect. In isolated rings of arteries, GLP-1 (10(-8) to 10(-5) M) induced a dose-dependent and time-reversible relaxation of preconstricted arteries. In a preparation with denuded epithelium, GLP-1 lost its effect. In conclusion, GLP-1 might represent another neuropeptide that acts as neurotransmitter of the peptidergic, nonadrenergic-noncholinergic nervous system that innervates the airways.
To assess the value of nuclear morphometry in the cytological diagnosis of urinary bladder carcinoma, washouts of the urinary bladder from 168 patients with histological established bladder cancer were studied. Morphometrical measurements were done on the nuclei of the exfoliated cells. This retrospective study showed that the nuclear parameter obtained by automated image analysis may be helpful in the differential diagnosis between neoplastic and non-neoplastic urinary bladder disease and correlate fairly with the classic histologic grading of malignancy in transitional cell carcinoma of the urinary bladder.