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71.

Background

Preparation for an H5N1 influenza pandemic in humans could include priming the population in the pre-pandemic period with a vaccine produced from an existing H5N1 vaccine strain, with the possibility of boosting with a pandemic virus vaccine when it becomes available. We investigated the longevity of the immune response after one or two priming immunizations with a whole-virus H5N1 vaccine and the extent to which this can be boosted by later immunization with either a homologous or heterologous vaccine.

Methods

Mice received one or two priming immunizations with a Vero cell culture-derived, whole-virus clade 1 H5N1 vaccine formulated to contain either 750 ng or 30 ng hemagglutinin. Six months after the first priming immunization, mice received either a booster immunization with the same clade 1 vaccine or a heterologous clade 2.1 vaccine, or buffer. Humoral and cellular immune responses were evaluated before and at regular intervals after immunizations. Three weeks after booster immunization, mice were challenged with a lethal dose of wild-type H5N1 virus from clades 1, 2.1 or 2.2 and survival was monitored for 14 days.

Results

One or two priming immunizations with the 750 ng or 30 ng HA formulations, respectively, induced H5N1-neutralizing antibody titers which were maintained for ≥6 months and provided long-term cross-clade protection against wild-type virus challenge. Both humoral and cellular immune responses were substantially increased by a booster immunization after 6 months. The broadest protective immunity was provided by an immunization regimen consisting of one or two priming immunizations with a clade 1 vaccine and a boosting immunization with a clade 2.1 vaccine.

Conclusions

These data support the concept that pre-pandemic vaccination can provide robust and long-lasting H5N1 immunity which could be effectively boosted by immunization either with another pre-pandemic vaccine or with the pandemic strain vaccine.  相似文献   
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Using isolated hemoglobin-free perfused rat livers we investigated the hepatotoxic effects of hypoxia, ethanol or the combination of both. Hypoxia only (90 min) led to a weak toxicity as evidenced by the efflux of the enzymes glutamate-pyruvate-transaminase (GPT) and sorbitol dehydrogenase (SDH). This toxic effect was slightly higher in livers treated with ethanol (3 g/l) under normoxic conditions. Ethanol added under hypoxic conditions, however, showed a strong hepatotoxic effect. Under hypoxic conditions, lactate + pyruvate production was increased fivefold over control, indicating that glycolysis was more effectively undergone as main source of energy. Addition of ethanol suppressed this effect, indicating that ethanol inhibited glycolysis. These results indicate that ethanol potentiates hypoxic liver damage by inhibiting the main metabolic pathway yielding ATP under low oxygen tension resulting in a severe energy deficit. Allopurinol (100 mg/l) inhibited the toxic effects seen with ethanol + hypoxia. Also, the inhibitory action of ethanol on glycolysis was antagonized. Our results are consistent with the following model: hypoxia converts NAD-dependent xanthine dehydrogenase (XD) into the oxygen-dependent xanthine oxidase (XO). Due to hypoxia and ethanol, purine metabolites and acetaldehyde accumulate and are metabolized via XO. This process leads to the production of oxygen radicals which most probably mediate both the inhibition of glycolysis and the direct toxic effects towards liver cells.  相似文献   
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BackgroundTo provide estimates of the nationwide prevalence of type 1 diabetes (T1D) and type 2 diabetes (T2D) in individuals younger than 20 years of age in Germany from 2002 to 2020 and to identify trends.MethodsData were obtained from the electronic health record “Diabetes Prospective Follow‐up Registry (DPV)” specific to diabetes care. Prevalence was estimated based on prevalent cases at the end of each year for the years 2002, 2008, 2014, and 2020 per 100 000 persons assuming a Poisson distribution and directly age‐ and/or sex‐standardized to the population in 2020. Individuals younger than 20 years of age with a clinical diagnosis of T1D or 10–19‐year‐olds with T2D were eligible for inclusion in the study.ResultsThe standardized T1D prevalence per 100 000 persons was 138.9 (95% CI: 137.1; 140.6) in 2002 and 245.6 (243.1; 248.0) in 2020. The standardized T2D prevalence per 100 000 persons was 3.4 (3.1; 3.8) in 2002 and 10.8 (10.1; 11.5) in 2020. The annual percent change (APC) in prevalence declined over the three periods 2002–2008/2008–2014/2014–2020 (T1D: 6.3% [3.6%; 9.0%]/3.1% [0.7%; 5.5%]/0.5% [−1.7%; 2.85], T2D: 12.3% [5.3%; 20.8%]/4.7% [−0.6%; 10.3%]/3.0% [−1.8%; 8.0%]). From 2014 to 2020, the highest APCs were observed among 15–19‐year‐olds (T1D: 2.5% [1.3%; 3.6%], T2D: 3.4% [−0.5%; 7.5%]).ConclusionsThe increase in diabetes prevalence has slowed, but medical care should be prepared for an increase in adolescents with diabetes.  相似文献   
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Abstract: Rats anaesthetized with pentobarbital and ventilated artificially were infused with 0.15 mg/kg/min. verapamil; without antidotal treatment, they died after 51.1 ± 7.1 min. The survival time more than trebled upon an additional infusion with calcium chloride, epinephrine, isoprenaline, orciprenaline or prenalterol and nearly doubled upon administration of a plasma expander. It was not increased, however, by treatment with angiotensin or atropine. The infusion of verapamil declined the arterial blood pressure by 75%, and heart rate, cardiac output and peripheral resistance by about 50%; in the ECG, sinus bradycardia followed by AV-dissociation with nodal rhythm occurred. All antidotes that raised the lethal dose of verapamil increased the cardiac output. Calcium and the sympathomimetics with α-adrenergic activity also counteracted the verapamil-induced hypotension. Calcium did not influence the ECG alterations produced by verapamil, while the sympathomimetics restored the sinus rhythm or accelerated the nodal pacemaker. Calcium, epinephrine and isoprenaline also antagonized the strong decrease of left-ventricular dp/dt max. induced by verapamil. In conclusion, calcium as well as sympathomimetic amines are potent antidotes against the cardiovascular toxicity of verapamil, the latter being superior to calcium in their ability to improve pacemaker activity and AV-conduction.  相似文献   
80.
We investigated the acute toxic and metabolic effects of 23-aliphatic alcohols (16 saturated and 7 unsaturated) in the isolated perfused rat liver at a concentration of 65.1 mmol/l (approximately 0.3% ethanol). The capacity of the straight chain primary alcohols (methanol, ethanol, 1-propanol, 1-butanol and 1-pentanol) to release the enzymes glutamate-pyruvate transaminase (GPT), lactate dehydrogenase (LDH) and glutamate dehydrogenase (GLDH) into the perfusate was strongly correlated with their carbon chain length. The secondary alcohols were less active in this respect whereas branching of the carbon chain did not consistently change alcohol toxicity. Unsaturation in the straight chain but not in the branched chain alcohols was accompanied by an increase in toxicity. An increased enzyme release was in general accompanied by, and correlated to, reductions in oxygen consumption, bile secretion, and perfusion flow of the isolated livers. Statistically significant correlations exist between parameters of alcohol-induced hepatotoxicity and the membrane/buffer partition coefficents of the alcohols. With the exception of methanol, all alcohols tested increased the lactate/pyruvate ratio of the perfusate, although this effect was not correlated to the degree of hepatic injury. Hepatic ATP concentrations decreased in most cases in line with hepatic injury and were particularly correlated with changes in oxygen consumption. Hepatic concentrations of reduced glutathione (GSH) were only diminished by the unsaturated alcohols, whereas an increase in hepatic oxidized glutathione (GSSG) occurred only with some of the saturated alcohols. Hepatic concentrations of malondialdehyde (MDA) increased after two saturated and three unsaturated alcohols but did not correlate with other parameters of hepatotoxicity. In conclusion, alcohol-induced hepatotoxicity is primarily due to membrane damage induced by the direct solvent properties of the alcohols. The consequences and relative contributions of alcohol metabolization to the overall hepatotoxicity of higher alcohols requires further study.  相似文献   
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