[Statement of the German Society for Pulmonology and Respiratory Medicine Regarding the Regulation to Use FFP and Surgical Masks in the General Population]. / Stellungnahme der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin zum Tragen von FFP- und chirurgischen Masken für die Bevölkerung.

On January 19, 2021, a new regulation on the mask requirement was issued in an initiative by the federal and state governments. This regulation obliges citizens to wear medical masks on public transport and in shops. In its statement, the German Society for Pneumology and Respiratory Medicine (DGP) describes the technical background of the various medical masks and explains their functionality using the associated standards. The DGP comes to the conclusion that FFP masks of the EN 149 standard were designed for the self-protection of the wearer and ensure this if the mask is worn properly and closes tightly to the face. Incorrect use must be avoided at all costs. Surgical masks in accordance with the EN 14683 standard were designed to protect against bacteria-carrying aerosols and, due to their design, have a rather low self-protection component. Community masks are not yet subject to any official standard. Community masks with electrostatic properties and high filtration performance could represent a reusable alternative in the future. Depending on the severity of their illness, patients with heart and/or lung diseases require a stress test with a mask to minimize medical risks.

[Abdominal free air without signs of perforated abdominal viscus during non-invasive ventilation]. / Freie abdominelle Luft ohne Hinweis auf eine Hohlorganperforation unter nichtinvasiver Beatmung.

HISTORY: A 19-year-old patient suffering from Duchenne muscular dystrophy was admitted to our hospital with an acute bronchopulmonary infection. Four months ago noninvasive ventilation was started because of hypercapnic respiratory failure. Mechanical ventilation had been used so far only at night. At the time of admission spontaneous breathing was not possible due to exhaustion of the respiratory muscles. The patient suffered from fever, limited cough strength and dyspnoea at rest. The abdomen was distended because of intestinal gas without clinical signs of acute abdomen. INVESTIGATIONS: Blood gas analysis showed respiratory acidosis even under mechanical ventilation. Laboratory tests showed an elevation of the inflammation indicating parameters. X-rays of the chest showed elevated diaphragms. Within the next days pneumonia could be seen in the left lower lobe. The patient had to be under mechanical ventilation almost 24 hours per day. Hypercapnia and respiratory acidosis normalized and the patient was able to breathe spontaneously for longer periods. The following days cutaneous emphysema developed and X-rays revealed free abdominal air on day 9 of the hospital stay. DIAGNOSIS, TREATMENT AND COURSE: The radiological findings have been confirmed during follow up X-rays without any clinical correlate. Inflammatory markers were decreasing. After the pneumonia had healed almost completely, the times on mechanical ventilation could be reduced. Subphrenic air resolved completely without any intervention. CONCLUSION: Free subphrenic air without any clinical signs of acute abdomen does not necessarily force a surgical exploration. Under frequent follow up investigations a wait-and-see strategy could be justified. An explanation for the subphrenic air could be an interstitial emphysema due to increased intrathoracic pressure caused by the prolonged noninvasive ventilation, releasing the air through the diaphragmatic gaps into the abdomen.

Inhibition of glutamine synthetase in rabbit pneumococcal meningitis is associated with neuronal apoptosis in the dentate gyrus.

Apoptosis of dentate granular cells in the hippocampal formation during bacterial meningitis may be mediated by glutamate toxicity. For this reason, we studied the relationship between glutamine synthetase activity and regional neuronal apoptosis in rabbits with experimental pneumococcal meningitis. The duration of meningitis was 24 h, and the treatment was started 16 h after infection. Significant increases of glutamine synthetase protein concentration (P < 0.05) were found in the frontal cortex of rabbits with meningitis (n = 7) and rabbits with meningitis receiving ceftriaxone treatment (n = 12) as compared to the control animals (n = 14). No significant differences were seen in the hippocampal formation. The enzymatic activity of glutamine synthetase also was elevated in the frontal cortex (P < 0.05), but not in the hippocampal formation of rabbits with meningitis. After intravenous administration of L-methionine sulfoximine (specific inhibitor of glutamine synthetase) in rabbits with meningitis treated with ceftriaxone (n = 10), the concentration of neuron-specific enolase in CSF (P = 0.025) and the density of apoptotic neurons in the dentate gyrus quantified with the in-situ tailing reaction (P = 0.043) were higher than in meningitic animals receiving only ceftriaxone (n = 10). In conclusion, the inability of hippocampal glutamine synthetase to metabolize excess amounts of glutamate may contribute to neuronal apoptosis in the hippocampal formation during meningitis.

Glutamine synthetase in experimental meningitis: increased ratio of the subunits 3 and 2 may indicate enhanced activity.

Glutamine synthetase (GS) activity is higher in the neocortex but not in the hippocampal formation of rabbit brain during Streptococcus pneumoniae meningitis compared to the respective brain region of uninfected control animals. One-dimensional polyacrylamide gel electrophoresis (1D-SDS-PAGE) revealed an apparent molecular mass (M(r)) of 44000 Dalton (Da) for GS from rabbit brain. After two-dimensional gel electrophoresis (2D-PAGE), followed by Coomassie-blue staining, GS separated into three distinct spots (S1, S2, S3). One additional spot (S4) occurred on the immunoblot. All four GS spots exhibited the same M(r) (44000 Da), but differed in their isoelectric points. Densitometric evaluation of the two-dimensional maps revealed a strong increase of optical density (OD) of S3 in the frontal cortex of infected animals. The calculated OD ratio S3/S2 in the frontal cortex from rabbits with meningitis was 1.75+/-0.68 (mean+/-standard deviation). Compared to controls (0. 85+/-0.39), this value was significantly increased (p=0.0006). In the hippocampal formation, the ratio S3/S2 was nearly unchanged during meningitis. It is suggested that the ratio S3/S2 may indicate a neuroprotective feature of rabbit brain during meningitis since neuronal apoptosis occurs only in the dentate gyrus and not in the frontal cortex.