The impact of frost-damage on the quality and quantity of the secreted antigen-specific IgG repertoire

Freezing of alum-based vaccines drastically alters their colloidal composition and leads to irreversible cluster formation. The loss of stability is well described, but the impact of frost damage on the functionality of the induced and secreted antibody repertoire has not been studied in detail. We therefore applied our single-cell measurement platform to extract the frequencies of Immunoglobulin G-secreting cells in combination with individual secretion rates and affinities. We showed that, frost-damaged or not, the tested vaccine was able to generate similar frequencies of total and antigen-affine IgG-secreting cells. Additionally, the frost-damaged vaccine stimulated a similar T-cell cytokine secretion pattern when compared to the regularly stored vaccine. However, frost-damaged vaccines induced no efficient affinity maturation and a complete collapse of the affinity distribution was observed. This study unveiled the impact of frost-damage to alum-based vaccines on the induced secreted antibody repertoire, and illustrated the power of functional single-antibody analysis.     

Freezing of gait in postmortem-confirmed atypical parkinsonism.

The frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem-confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty-six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies.     

低温保存同种心脏瓣膜活性及临床应用的研究

取正常成人心脏瓣膜３６个，置于低浓度广谱抗生素的营养液（ＲＰ－ＭＩ１６４０细胞培养液）中灭菌４８ｈ，－８０℃冰箱初冻，置于液氮中长期保存。灭菌前后瓣膜细菌培养阴性率分别为９４．３％和１００％，解冻后经光镜、电镜检查证实瓣组织细胞结构正常，组织培养葡萄糖消耗率测定示瓣组织存活良好。临床同种心脏瓣膜原位移植３例，随访６～３０个月，瓣功能良好     

小鼠卵母细胞玻璃化冷冻的研究

目的　对小鼠卵母细胞玻璃化的方法和冷冻液进行研究。方法　用两种玻璃化冷冻液EFS4 0 (高钠 )、DEFS4 0 (低钠 )对ICR、C57BL 6J小鼠卵母细胞进行冷冻 ,0 5mol L蔗糖液解冻 ,体外授精前对部分解冻后的C57BL 6J小鼠卵母细胞进行透明带切割。结果　DEFS4 0冷冻液冷冻效果明显高于EFS4 0冷冻液 ,ICR小鼠卵母细胞解冻后成活率达 75 2 %、体外授精率 (2 4 6 % )与对照组相比差异无显著性 ,C57BL 6J小鼠卵母细胞解冻后成活率为 87 1%、卵母细胞切割后体外受精率 (36 0 % )与对照组相比差异也无显著性。结论　冷冻液中钠离子浓度影响小鼠卵母细胞冷冻效果 ,用DEFS4 0 (低钠 )冷冻液进行玻璃化冷冻可以取得理想的冷冻效果。     

FD-1冷冻干燥机的研制及生物材料的冷冻干燥

观察自制冷冻干燥机冷冻干燥生物材料的效果。采用 R5 0 2压缩机和制冷剂制成 FD- 1冷冻干燥机。本实验冷冻干燥了胶原海绵、菌种及去纤酶。在冻干箱负载或空载情况下蒸发冷凝器温度均可达到 - 4 5℃ ,小冰箱可达到 - 30℃ ,冻干的胶原海绵具有许多孔洞的结构 ,冻干的菌种和去纤酶性能保持良好。 FD- 1冷冻干燥机适用于生物样品中小批量的冷冻干燥     

Olfactory bulbectomy: emotional behavior and defense responses in the rat

Removal of the olfactory bulbs of male hooded rats caused a reduction in defensive reactions to an unconditioned aversive stimulus (mechanical robot). In the presence of the robot, bulbectomized rats showed significantly less freezing and significantly less suppression of feeding behavior than sham-operated controls. At the same time, the bulbectomized rats were significantly more irritable to handling and showed a significant increase in muricide. These effects could not be attributed to loss of olfactory perception alone. Rats made peripherally anosmic through surgical removal of olfactory afferents were virtually indistinguishable from controls. These results provide further evidence for the view that in addition to their sensory functions, the olfactory bulbs of the rat have important tonic influences on emotional behavior. These tonic influences can occur independently of sensory processing and seem to be critical for the normal expression of emotional behavior or defense responses in this animal.     

5-HT mechanisms of median raphe nucleus in the conditioned freezing caused by light/foot-shock association

We have shown that 5-HT mechanisms of the median raphe nucleus (MRN) are involved in contextual fear-conditioning processes as electrolytic or neurotoxic lesions with N-methyl-D-aspartate (NMDA) or injections of 8-hydroxy-2-(di-n-propilamino)-tetralin (8-OH-DPAT) into this structure inhibit freezing behavior in a contextual fear paradigm. In this work, we extend these studies by analyzing the behavioral responses in a classical fear-conditioning paradigm (light or tone/foot-shock association) in rats with either neurochemical lesion with NMDA or injected with 8-OH-DPAT into the MRN. The animals received NMDA or 8-OH-DPAT or saline microinjections into the MRN and were submitted to conditioning trials in an experimental chamber, where they received 10 foot-shocks (0.6 mA, 1 s, variable interval between 10 and 50 s) paired with tone or light (CS). On the next day, they were tested in a different experimental chamber, with or without CS presentation, where the duration of freezing and the number of rearing episodes were recorded. Light or tone alone caused a significant amount of freezing. NMDA lesions or 8-OH-DPAT injections into the MRN clearly inhibited freezing behavior in rats conditioned to light/foot-shock association, but not in the conditioning sessions with tones. Besides the proposed role in contextual fear conditioning, these results clearly show that MRN is involved in the fear conditioning with light as conditioned stimuli. Distinct neural substrates seem to subserve conditioning fear with acoustic stimuli.     

Determination of oxidative stress parameters and DNA fragmentation on post-thawed buck semen in the presence of ram seminal plasma and fetal calf serum

The aim of the study was to investigate the efficiency of ram seminal plasma and fetal calf serum on freezing of buck semen. Twenty ejaculates were collected using an electro-ejaculator and split into six groups. While FCS additive was not used in A1, A2 and A3 groups, 10% FCS was added to B1, B2 and B3 groups. These groups were then edited according to whether the buck or ram SP was involved. The design of the groups was done as follows: Group A1 (control 1), group A2 without buck SP, group A3 containing ram SP instead of buck SP. Groups B1 (control 2), B2 and B3 were the FCS added forms of these groups. Progressive sperm motility percentages in Group A1 and Group B2 were found to be higher when compared to the lowest Group B3. There were no significant differences between the groups in neither the levels of reactive oxygen species nor the enzyme and glutathione activities. In conclusion, the lack of statistical difference between the groups suggested that despite the supplements used but only when the buck spermatozoa structure was healthy, the cell could preserve acrosome, DNA and the integrity of membrane.     

l-Sulpiride, at a low, non-neuroleptic dose, prevents conditioned fear stress-induced freezing behavior in rats

Antidepressant drugs are effective in anxiety states, including panic disorder. Both clinical and animal studies indicate that l-sulpiride, at low, non-neuroleptic doses, has antidepressant activity. The present study examined the effect of an antidepressant dose of l-sulpiride (4 mg/kg per day SC), compared with a well-established antidepressant drug (fluoxetine, 3 mg/ kg per day SC), in a rat model of anticipatory anxiety/panic behavior: conditioned fear stress-induced freezing behavior. Long-term (26 days) administration of l-sulpiride almost completely abolished freezing, a similar effect being produced by fluoxetine (freezing duration, in seconds: controls, 148.1 ± 29.6; l-sulpiride, 27.5 ± 8.3; fluoxetine, 72.0 ± 15.2). The same doses of l-sulpiride (4 mg/kg SC) and fluoxetine (3 mg/kg SC) had no effect when administered for shorter periods (1, 5, or 12 days). No effect was produced by the long-term (26 days) administration of a neuroleptic dose of l-sulpiride (20 mg/kg per day SC). These results demonstrate that long-term administration of low, non-neuroleptic doses of l-sulpiride, is highly effective in an animal model of anticipatory anxiety/panic behavior. Received: 13 March 1998/Final version: 23 July 1998     

Conditioned fear to environmental context: cardiovascular and behavioral components in the rat

This study compares the time course of the cardiovascular changes (mean arterial blood pressure, heart rate) and behavioral changes (freezing, rearing, grooming and activity) evoked by 30 min long exposures to a footshock chamber before and after conditioning with footshocks. The main finding is that the conditioned fear evoked by re-exposure to the footshock chamber after conditioning is associated with a prolonged freezing response, a marked rise in mean arterial pressure (+35 mm Hg above a resting baseline of 105 mm Hg) and a delayed rise in heart rate. The pattern of behavioral and cardiovascular changes is the same as with conditioned fear to a discrete stimulus but the effect is a lot longer.