Experimental axonopathy induced by immunization with campylobacter jejuni lipopolysaccharide from a patient with guillain‐barré syndrome

Campylobacter jejuni (C. jejunj) infection is the most common antecedent in the axonal variant of Guillain‐Barré syndrome (GBS). Antibodies against nerve gangliosides found in GBS patients recognize cross‐reactive epitopes in the lipopolysaccharide (LPS) of C. jejuni. This led to the molecular mimicry hypothesis of GBS. We immunized eleven rabbits with a LPS extracted from HS:19 C. jejuni strain isolated from a patient with GBS and complete Freund's adjuvant (CFA)(group I). In a second experiment we immunized seven rabbits with LPS, CFA and keyhole limpet hemocyanin (KLH)(group II). All group I rabbits developed high titers of anti‐LPS, anti‐GM1, anti‐GD1b antibodies and lower titers of anti‐GD1a. One rabbit, 50 days after initial inoculation, showed tremor and weakness. All rabbits of group II developed high titres of antiganglioside antibodies and six animals showed weakness 59–113 days after initial inoculation. Two rabbits died. Pathology showed mild to moderate, tendentially grouped, axonal degeneration in sciatic nerves of four out of five animals. Control rabbits of group I (immunized with CFA only) did not develop antibodies, controls of group II (immunized with CFA + KLH) developed low titers of IgG anti‐GM1. None developed neurological signs or showed axonal degeneration. C. jejuni LPS is a potent B‐cell stimulator capable to induce a strong antiganglioside response in rabbits. However, to induce the neuropathy is crucial to employ KLH, a glycoprotein known to stimulate both humoral and cellular responses. This animal model reproduces the pathogenetic process hypothesized in axonal GBS with antiganglioside antibodies post C. jejuni infection.     

Studies of Whole Blood Associated Acetaldehyde as a Marker for Alcohol Intake in Mice

Thirty C57BI mice were randomized into two groups. Group 1 served as controls while Group 2 was given 10% V/V ethanol with the drinking water. Whole blood- associated acetaldehyde (WBAA) was measured on capillary blood samples using a fluorigenic high performance chromatographic assay. WBAA peaked at Day 2. A stable mean plateau of 263 +/- 71 SD with a range of 160-400 nmoles/g hemoglobin WBAA was found in the group consuming ethanol compared with 122 +/- 17 SD and a range of 88-150 nmoles/g hemoglobin for controls (p less than 0.001). When ethanol was discontinued, levels of WBAA declined and became similar to those of controls by 9 days following cessation of ethanol. The quantitative difference between ethanol-consuming and control animals and also the rapid rise of whole blood-associated acetaldehyde and the relatively slow decline following cessation of ethanol intake indicate that such a test might be a useful monitor of drinking behavior.     

Network analytic methods for epidemiological risk assessment

The authors measure the efficacy of three methods for predicting the time to infection for susceptible individuals in a population undergoing an HIV epidemic. The methods differ in whether they require detailed information of the contact network and whether they require knowledge of the initial source of infection. Efficacy is evaluated using simulations for 20 different contact patterns. Only the risk score that uses both kinds of information accounts for more than 15 per cent of individual variability. The efficacy of this score ranges from 10 per cent in very unstructured populations to 60 per cent for spatially localized contact networks. This improved performance may be explained by the larger fraction of the total variability not due to the disease dynamics. When all variables are dichotomized, the two poorer methods produce odds ratios between 1.4 and 2.3. The odds ratio for the risk score with full information ranges from 2.5 to 17. Risk assessment protocols and intervention programmes are encouraged to assess contact patterns and detect sources of infection.     

Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci.

Specific proteolytic destruction of the human chemotaxin, C5a, is a property of group A and B streptococcal pathogens. Here we show that virulent group G streptococci from human sources also express C5a peptidase activity. The enzyme responsible for this activity is approximately the same size as and is antigenically similar to that produced by group A streptococci. On the basis of Southern hybridization analysis with an internal fragment of the group A C5a peptidase gene (scpA) as a probe, a copy of this gene was found in the genome of all group G human isolates tested. Comparison of partial restriction maps of scpA and scpG revealed significant similarity between the two genes. Group G strains isolated from dogs and cows were found to lack C5a peptidase activity and did not hybridize to the scpA-specific probe. The association of this activity with three streptococcal species suggests that elimination of phagocyte chemotactic attractants is a more universal virulence mechanism than originally anticipated.     

Treatment and prognosis of lymphoblastic lymphosarcoma in children]

Analysis was made of the results of the treatment of 18 children afflicted with lymphoblastic lymphosarcoma, with estimation of predictors influencing the patients' survival (from 1980 to 1986). The most important predictors influencing the 2-year relapse-free survival were found to be the stage, localization of the process, the presence of the symptoms of intoxication and biological activity. The data obtained were used later in the treatment of 160 children during 1986 to 1989. The results of the 2-year survival of this patients' group appreciably differ from those derived before.     

图雷特综合征患儿成年期的抽搐和强制性障碍症状严重程度的转归

背景：图雷特综合征（TS）是一种儿童期发作的，以运动和语音性抽搐为特征的神经精神疾病。1／2～2／3患具有TS发作史的儿童，其抽搐症状在成年期缓解或完全缓解。至少1／3的TS成年患伴有强迫性神经失调（OCD）。目的：阐明TS患儿抽搐和OCD症状的临床过程；确定儿童期基线临床测量结果，是否与将来青春晚期和成人早期症状的严重程度有关。