Analysis of tuberculosis surveillance in Hungary in 2000

SETTING

Hungary, Central Europe, with a population of 10.3 million living in 20 administrative districts (19 counties and the capital).

OBJECTIVE

To summarize the results of the first year of the revised National Tuberculosis Surveillance System.

DESIGN

Retrospective survey of the National Tuberculosis Surveillance Center (NTSC) database.

METHODS

Analysis of data on all tuberculosis cases reported to the NTSC in 2000. Drug susceptibility results were evaluated in line with WHO and IUATLD definitions.

RESULTS

During 2000, a total of 3598 patients with tuberculosis were reported. Only 40% of these were bacteriologically confirmed. Although susceptibility testing has been required for previously untreated culture-positive cases, only 801 (67.8% of the bacteriologically confirmed cases) were tested in 2000. Drug resistance was detected in 10.7% of previously untreated and in 23.5% of previously treated patients. Multidrug-resistant (MDR) cases were not common: only 1.5% of the isolates from previously untreated patients and 4.9% of those from previously treated patients were MDR.

CONCLUSIONS

The results suggest that the NTSC should work towards increasing the numbers of cases that are bacteriologically confirmed. In addition, some form of surveillance system should be instituted to ensure that mandatory susceptibility testing is performed on all isolates from previously untreated tuberculosis patients.

Ultrastructural changes of the neuromuscular junction in reperfusion injury

Ischemia followed by reperfusion of skeletal muscle frequently takes place in trauma surgery. Anoxia followed by reoxygenation leads to reperfusion injury, which damages the involved tissues. However, no information is available about how the neuromuscular junction is affected by ischemia-reperfusion. Tourniquet ischemia of the left hind limb was applied in the anesthetized rat for 2 h. Reperfusion lasted for 2 and 24 h and for 1, 2 and 4 weeks. The extensor digitorum longus and the soleus muscles from both legs were prepared for electron-microscopic analyses. Morphological changes of the neuromuscular junction were investigated. In all cases only the nerve endings (terminals) were affected. The postsynaptic structures were not affected. Changes can be grouped in two categories: degeneration and recovery. Degeneration consisted of the loss of synaptic vesicles, disruption of the presynaptic membrane, degeneration of the mitochondria and the development of vacuoles. It was most severe at 24 h and was still present at 4 weeks of reperfusion. Recovery started at 1 week of reperfusion and lasted at least for 4 weeks. It consisted of the slow reappearance of synaptic vesicles and mitochondria, and restoration of the presynaptic membrane with active zones. Ultrastructure of the skeletal muscle fibers did not show pathological changes. The recovery of the structures may be regulated by the Schwann cells and also by the postsynaptic membrane which is not affected by 2 h of ischemia followed by reperfusion.

Quantitation of the alveolar distribution of surfactant mixtures in normal and injured lungs

The uptake and distribution of two surfactant mixtures, Exosurf and Infasurf, instilled into the lungs of normal and hyperoxia-exposed (100% O2, 60 h) rabbits, were quantified at the alveolar level using flow cytometry and fluorescence microscopy. The surfactants were labeled with the fluorescent phospholipid analog NBD-C12-PC (1-palmitoyl-2-[12-[(7-nitro-2-1, 3-benzoxadiazol-4-yl)amino]dodecanoyl]-sn-glycero-3-phosphocholine ) in 100:1 molar ratio. Rabbits were killed 2 h after the instillation of either surfactant (80 mg phospholipid [PL]/kg), and alveolar macrophages (AM) and alveolar type II (ATII) cells were isolated and examined for the presence of NBD fluorescence. The fractions of cells, with NBD fluorescence values higher than autofluorescence, isolated from the lungs of air-breathing rabbits instilled with either Infasurf or Exosurf, were 84% and 63% for AM, and 55% and 45% for ATII cells. Exposure of rabbits to hyperoxia decreased the fraction of NBD-positive AM following Infasurf instillation, and the mean increase in NBD-associated fluorescence in ATII cells following Exosurf instillation. Our results suggest that sublethal hyperoxia decreases the short-term uptake but not the distribution of intratracheally instilled Exosurf.

Clinical surfactant preparations mediate SOD and catalase uptake by type II cells and lung tissue

Pulmonary surfactant mixtures are rapidly taken up by alveolar type II cells and thus may serve as vectors for the pulmonary delivery of antioxidant enzymes to the alveolar epithelium. We prepared emulsions of Survanta with superoxide dismutase (CuZn-SOD) and catalase and quantified their cellular uptake both in vitro and in vivo. Incubations of fetal lung epithelial cells with an emulsion of Survanta plus SOD and catalase mixtures resulted in significant augmentation of SOD and catalase activities (12.8 +/- 4.6 U SOD/microgram DNA; 7.49 +/- 2.21 U catalase/microgram DNA). These numbers were significantly greater than those obtained in controls (1.8 U SOD/microgram DNA; 0.55 +/- 0.52 U catalase/microgram DNA, Survanta alone (0.43 U SOD/microgram DNA; 0.16 U catalase/microgram DNA), and SOD and catalase alone (3.47 +/- 5.2 U SOD/microgram DNA; 4.24 +/- 3.0 U catalase/microgram DNA). Intratracheal instillation of the Survanta plus SOD and catalase mixture resulted in significant augmentation of enzymes by the rat lung homogenates. Confocal microscopic analysis revealed the presence of antioxidant enzymes in the cytoplasm of epithelial cells. We concluded that Survanta supplementation, in addition to replenishing surfactant stores, can also enhance the delivery of antioxidant enzymes to alveolar epithelium both in vitro and in vivo.

Regulation of fluid-phase endocytosis in alveolar macrophages

We investigated whether fluid-phase endocytosis in rabbit alveolar macrophages (AM) was regulated by alterations in intracellular adenosine 3',5'-cyclic monophosphate (cAMP). Suspensions of freshly isolated AM were incubated with anionic dextrans (mol mass = 10 kDa), coupled to fluorescein isothiocyanate (FITC), at either 37 or 4 degrees C. There was a rapid increase in AM-associated fluorescence, quantified by laser flow-cytometry and video microscopy during the first hour of incubation at 37 degrees C, which was directly proportional to the amount of tracer present in the medium. In contrast, at 4 degrees C, AM fluorescence was similar to autofluorescence. Incubation of AM with forskolin (50 microM) or 3-isobutyl-1-methyl xanthine (IBMX; 0.1 mM) increased their cAMP content by 67 +/- 2 and 52 +/- 5% (mean +/- SE; n = 4) and decreased FITC-dextran uptake by 29 +/- 4 and 31 +/- 4% (n = 3). On the other hand, incubation of AM with 0.5 mM IBMX inhibited FITC-dextran uptake by 62 +/- 4% (n = 3), without any further increase in cAMP. Incubation of AM with 0.4 mM 8-(4-chlorophenylthio)-adenosine 3',5'-cyclic monophosphate (CPT-cAMP), a cell-permeable analogue of cAMP, decreased FITC-dextran uptake by 48 +/- 5% (n = 6). Pulse-chase experiments showed that the rate of FITC-dextran exocytosis was not affected by cAMP. We concluded that fluid-phase endocytosis in rabbit AM is regulated by cAMP and by an additional, cAMP-independent mechanism of IBMX.

[Bone and joint tuberculosis in Hungary today]

Authors introduce to the history of efforts against tuberculosis in Hungary. The effectiveness of this figh is shown by the decrease of morbidity rates. The decrease of morbidity rates was followed by the cutting down of the system of institutions devoted to the conquest of tuberculosis. Authors give account on the present epidemiological conditions and report on the four and a half years activity of their bone and joint surgery department in this field. The department proved to be reliably suitable for the treatment of patients with bone and joint tuberculosis. They draw the attention to the significance of yearly 30 cases which show that the tuberculosis did not yet disappear from Hungary. The aim of the paper is to maintain the problem in the common medical consciousness.

Quantitation of nitrotyrosine levels in lung sections of patients and animals with acute lung injury

Activated alveolar macrophages and epithelial type II cells release both nitric oxide and superoxide which react at near diffusion-limited rate (6.7 x 10(9) M-1s-1) to form peroxynitrite, a potent oxidant capable of damaging the alveolar epithelium and pulmonary surfactant. Peroxynitrite, but not nitric oxide or superoxide, readily nitrates phenolic rings including tyrosine. We quantified the presence of nitrotyrosine in the lungs of patients with the adult respiratory distress syndrome (ARDS) and in the lungs of rats exposed to hyperoxia (100% O2 for 60 h) using quantitative immunofluorescence. Fresh frozen or paraffin-embedded lung sections were incubated with a polyclonal antibody to nitrotyrosine, followed by goat anti-rabbit IgG coupled to rhodamine. Sections from patients with ARDS (n = 5), or from rats exposed to hyperoxia (n = 4), exhibited a twofold increase of specific binding over controls. This binding was blocked by the addition of an excess amount of nitrotyrosine and was absent when the nitrotyrosine antibody was replaced with nonimmune IgG. In additional experiments we demonstrated nitrotyrosine formation in rat lung sections incubated in vitro with peroxynitrite, but not nitric oxide or reactive oxygen species. These data suggest that toxic levels of peroxynitrite may be formed in the lungs of patients with acute lung injury.