[Research on cone-beam CT of mandibular foramen location in children aged 7-10 years]

Objective: Cone-beam CT (CBCT) images were used to investigate the relative position changes of mandibular foramen in the mandible of children and the relative position relationship with the occlusal plane, so as to provide clinical guidance for inferior alveolar nerve block (IANB) anesthesia of children. Methods: The CBCT data of 202 children aged 7-10 years in the image database of the First Affiliated Hospital of Zhengzhou University from March 2021 to February 2023 were included. Patients were divided into 4 groups according to age diffrences as 7-year-old, 8-year-old, 9-year-old and 10-year-old. There were 20 males and 22 females in the 7-year-old group, 31 males and 28 females in the 8-year-old group, 30 males and 26 females in the 9-year-old group, and 22 males and 23 females in the 10-year-old group, respectively. Forty-six adults aged 25-30 years were selected as control group, 24 males and 22 females included. The distance between the center point of mandibular foramen with the anterior edge of ascending ramus of mandible (MF-A), the posterior edge of the ascending ramus of mandible (MF-P) and the shortest distance between the center point of mandibular foramen with occlusal plane (MF-OP) were measured. The angle between the center point of the mandibular foramen with the sagittal plane of the mandibular first deciduous molar (or mandibular first premolar) and mandibular second deciduous molar (or mandibular second premolar) (∠A) was measured. The data of mandibular foramen were compared between the left and right sides and among different genders and different age groups. Results: The position of mandibular foramen in children aged 7-10 years maintained bilateral symmetry, and mandibular growth and development were relatively consistent between different genders (P>0.05). MF-A increased with age, from (15.83±1.28) mm in 7-year-old group to (17.10±1.60) mm in 10-year-old group gradually. There were significant differences in MF-A between the 10-year-old group with the 7-year-old group, the 8-year-old group [(15.98±1.53) mm] and the 9-year-old group [(16.43±1.49) mm] respectively (P<0.05). MF-P increased with age, from (9.12±1.17) mm in 7-year-old group to (11.25±1.60) mm in 10-year-old group. There were statistically significant differences in MF-P among all age groups (P<0.05). MF-OP increased with age, from below the plane (-0.24±2.31) mm in the 7-year-old group to above the plane (1.08±1.95) mm in the 10-year-old group. There were significant differences between the 10-year-old group with the 7-year-old group, the 8-year-old group [(-0.01±1.93) mm], and the 9-year-old group [(0.31±1.95) mm] (P<0.05). The ratio of MF-A to MF-P decreased as the age increased, from 1.77±0.30 in the 7-year-old group to 1.55±0.29 in the 10-year-old group. There were statistically significant differences in MF-A/MF-P among all age groups (P<0.05), except for between the 8-year-old group (1.66±0.19) and the 9-year-old group (1.65±0.28) (P>0.05). The ∠A of children in all age groups was significantly greater than the reference value (45°) (P<0.05), and there was no statistical significance among all groups (P>0.05). The differences of MF-A, MF-P, MF-OP, MF-A/MF-P and ∠A between children of all age groups and the control group were statistically significant (P<0.05). Conclusions: In children aged 7-10 years, the mandibular foramen is located behind the midpoint of the anteroposterior diameter of the mandibular ramus. With the increase of age, the mandibular foramen gradually moves from below the occlusal plane to above, and is flush with the occlusal plane at the age of 8 years. Compared with adults, the mandibular foramen in children is more backward and lower on the medial side of the mandibular ramus. When IANB is operated to children, the syringe can be moved distally from the contact area of the contralateral deciduous molars or premolars, so that the injection angle can be greater than the reference value 45° to improve the accuracy of IANB.

[Evaluation of the efficacy of GnRH-a pretreatment before total hysterectomy for adenomyosis patients: a propensity score matching analysis]

Objective: To evaluate the efficacy of gonadotropin-releasing hormone agonist (GnRH-a) pretreatment before total hysterectomy for adenomyosis patients with uterine volume ≥12 gestational weeks and moderate or severe anemia. Methods: From January 2018 to March 2023, 689 patients who underwent total hysterectomy for adenomyosis in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. According to the preoperative medication, they were divided into study group (127 cases) and control group (562 cases). Patients in the study group underwent GnRH-a pretreatment for 3 cycles before surgery, and the control group received operation directly. SPSS 26.0 software was used to perform 1∶1 matching for the two groups of patients through the propensity score matching method. Matching variables included age, body mass index, gravidity, parity, history of pelvic and abdominal surgery, menstrual cycle, menstrual period, dysmenorrhea score, initial diagnosis of cancer antigen 125 (CA125), uterine volume and hemoglobin value. The dysmenorrhea score, uterine volume, hemoglobin value and CA125 level before and after GnRH-a pretreatment in the study group were compared. And the duration of operation, intraoperative blood loss, postoperative white blood cell count, perioperative blood transfusion cases, postoperative disease rate, duration of hospitalization, total hospitalization cost between the two groups were compared. Results: With propensity score matching, 119 patients in the study group and 119 patients in the control group were finally enrolled in this study. In the study group, before and after the treatment with GnRH-a, the dysmenorrhea score (7.4±1.7 vs 5.6±1.8), uterine volume [(362±160) vs (233±126) cm3], hemoglobin value [(74.1±10.7) vs (102.5±13.5) g/L], and CA125 level [(104±76) vs (64±51) kU/L] were statistically different (all P<0.05). There were statistical differences of operation time [(86±18) vs (116±31) minutes], intraoperative blood loss [(24±9) vs (43±22) ml], white blood cell count after 1 day of operation [(9.80±0.10)×109/L vs (9.90±0.10)×109/L], number of perioperative blood transfusion case [5.9% (7/119) vs 61.3% (73/119)], postoperative disease rate [5.0% (6/119) vs 16.0% (19/119)], hospitalization duration [(7.1±1.6) vs (7.9±1.6) days], and total hospitalization cost [(35 323±5 275) vs (37 159±5 640) yuan] between the study group and the control group (all P<0.05). Conclusion: The pretreatment of using GnRH-a before total hysterectomy for adenomyosis patients with uterine volume ≥12 gestational weeks and moderate or severe anemia is not only conducive to improving dysmenorrhea, signs of anemia, reducing uterine volume, but also conducive to the implementation of surgery, reducing intraoperative and postoperative complications, and reducing hospital costs.

[Safety and effectiveness of esophagojejunostomy through extracorporeal versus intracorporeal methods after laparoscopic total gastrectomy]

Objective: To compare the safety and effectiveness of esophagojejunostomy (EJS) through extracorporeal and intracorporeal methods after laparoscopic total gastrectomy (LTG). Methods: A retrospective cohort study was carried out. Clinicopathological data of 261 gastric cancer patients who underwent LTG, D2 lymphadenectomy, and Roux-en-Y EJS with complete postoperative 6-month follow-up data at the General Surgery Department of Nanfang Hospital from October 2018 to June 2021 were collected. Among these 261 patients, 139 underwent EJS with a circular stapler via mini-laparotomy (extracorporeal group), while 122 underwent intracorporeal EJS (intracorporeal group), including 43 with OrVil(TM) anastomosis (OrVil(TM) subgroup) and 79 with Overlap anastomosis (Overlap subgroup). Compared with the extracorporeal group, the intracorporeal group had higher body mass index, smaller tumor size, earlier T stage and M stage (all P<0.05). Compared with the Overlap subgroup, the Orvil(TM) subgroup had higher proportions of upper gastrointestinal obstruction and esophagus involvement, and more advanced T stage (all P<0.05). No other significant differences in the baseline data were found (all P>0.05). The primary outcome was complications at postoperative 6-month. The secondary outcomes were operative status, intraoperative complication and postoperative recovery. Continuous variables with a skewed distribution are expressed as the median (interquartile range), and were compared using Mann-Whitney U test. Categorical variables are expressed as the number and percentage and were compared with the Pearson chi-square, continuity correction or Fisher's exact test. Results: Compared with the extracorporeal group, the intracorporeal group had smaller incision [5.0 (1.0) cm vs. 8.0 (1.0) cm, Z=-10.931, P=0.001], lower rate of combined organ resection [0.8% (1/122) vs. 7.9% (11/139), χ(2)=7.454, P=0.006] and higher rate of R0 resection [94.3% (115/122) vs. 84.9 (118/139), χ(2)=5.957, P=0.015]. The morbidity of intraoperative complication in the extracorporeal group and intracorporeal group was 2.9% (4/139) and 4.1% (5/122), respectively (χ(2)=0.040, P=0.842). In terms of postoperative recovery, the extracorporeal group had shorter time to liquid diet [(5.1±2.4) days vs. (5.9±3.6) days, t=-2.268, P=0.024] and soft diet [(7.3±3.7) days vs. (8.8±6.5) days, t=-2.227, P=0.027], and shorter postoperative hospital stay [(10.5±5.1) days vs. (12.2±7.7) days, t=-2.108, P=0.036]. The morbidity of postoperative complication within 6 months in the extracorporeal group and intracorporeal group was 25.9% (36/139) and 31.1%, (38/122) respectively (P=0.348). Furthermore, there was also no significant difference in the morbidity of postoperative EJS complications [extracorporeal group vs. intracorporeal group: 5.0% (7/139) vs. 82.% (10/122), P=0.302]. The severity of postoperative complications between the two groups was not statistically significant (P=0.289). In the intracorporeal group, the Orvil(TM) subgroup had more estimated blood loss [100.0 (100.0) ml vs.50.0 (50.0) ml, Z=-2.992, P=0.003] and larger incision [6.0 (1.0) cm vs. 5.0 (1.0) cm, Z=-3.428, P=0.001] than the Overlap subgroup, seemed to have higher morbidity of intraoperative complication [7.0% (3/43) vs. 2.5% (2/79),P=0.480] and postoperative complications [37.2% (16/43) vs. 27.8% (22/79), P=0.286], and more severe classification of complication (P=0.289). Conclusions: The intracorporeal EJS after LTG has similar safety to extracorporeal EJS. As for intracorporeal EJS, the Overlap method is safer and has more potential advantages than Orvil(TM) method, and is worthy of further exploration and optimization.

Deep small RNA-Seq reveals microRNAs expression profiles in lactating mammary gland of 2 sheep breeds with different milk performance

Micro ribonucleic acid (miRNA) is a type of noncoding RNA, and it has been revealed to play important roles in the activity of the mammary gland (MG) in some species. However, the function of miRNAs in MG of sheep is poorly understood. In the study, Gansu Alpine Merino (GAM; n = 9) and Small-tailed Han sheep (STH; n = 9) with different milk production traits were investigated. Microstructures and the expression profile of miRNAs of MG tissues at peak lactation were studied. Mature alveolar lumens of MG in appearance were larger in STH than GAM. The expression levels of CSN2 and the content of rough endoplasmic reticulum were also higher in STH ewes than GAM ewes. A total of 124 mature miRNAs were expressed, and 18 of these were differentially expressed between the 2 breeds. The KEGG analysis results showed that the targeted genes of differentially expressed miRNAs were mainly involved in some metabolic pathways and signaling pathways related to MG development, milk protein, and fat synthesis. The findings in the study can improve our understanding of the roles of miRNAs in the development and lactation of MG in sheep.

[Management strategy for the resumption of regular diagnosis and treatment in gastrointestinal surgery department during the outbreak of coronavirus disease 2019 (COVID-19)]

Acute abdomen, abdominal trauma, gastrointestinal bleeding and gastrointestinal tumors are the main conditions that are routinely treated in gastrointestinal surgery department with high incidence and critical condition. These conditions need emergency or selective operations. During the outbreak of the coronavirus disease 2019 (COVID-19), it's a great challenge for us to meet the patients' requirement under the situation. As the COVID-19 was brought under control in China, the Department of General Surgery in Nanfang Hospital resumed regular medical services gradually. Based on our clinical practice, the four major measures of strengthening pre-hospital screening, perioperative prevention and control, medical staff protection, and ward management were adopted. These main measures include the strict implementation of the appointment system and triage system before admission; the conduction of epidemiological and preliminary screening of viral nucleic acids; the chest CT examination during the perioperative period to re-screen COVID-19; the reduction of the risk of droplets and aerosol transmission; the minimally invasive surgery combined with enhanced recovery program in order to reduce patient's susceptibility and shorten the length of postoperative hospital stay; the reinforcement of specific infection control training for medical staff; the strict implementation of hierarchical protection; the establishment of gastrointestinal surgery prevention and control system; the rehearsal of emergency exercise; the installation of quarantine wards; the screening and management of family care-givers; the strict disinfection of environment and materials. Our preliminary practice shows that following the work guidelines issued by the Guangdong Province COVID-19 Prevention and Control Office and adopting precise management strategies in combination with the specific clinical features of gastrointestinal surgery, it is possible to safely resume regular care for the patients and comply to epidemic control at the same time.

[Clinical analysis of leiomyomatosis peritonealis disseminate after laparoscopic uterine myomectomy in ten cases]

Objective: To investigate the clinicopathological features, treatment and prognosis of leiomyomatosis peritonealis disseminata (LPD). Methods: A total of 10 patients suffered from LPD after laparoscopic uterine myomectomy were collected in the First Affiliated Hospital of Zhengzhou University from September 2012 to September 2016, and all clinical database were retrospectively analyzed. Results: (1)Clinical features: the age of 10 cases was 25-50 years old, and 8 cases of them were in child-bearing age, while 2 cases were in perimenopausal period. Of 10 cases, 2 cases manifested as discontinuous lower abdominal pain, and the other cases were seen the doctor for the examinations found tumors of pelvis or abdomen. All 10 cases had a history of laparoscopic uterine myomectomy under went power morcellation with an average of (4.0±2.2) years (range 1.3 to 8.1 years), 2 cases of them had a history of oral hormone treatment after the first myoma morcellation. (2) Treatment methods and postoperative pathologic diagnosis: during intraoperative exploration, LPD nodules were most distributed in Douglas pouch (10 cases), and next in mesentery (7 cases), abdominal peritoneum (6 cases) and omentum majus (4 cases), etc. Seven of the 8 cases of child-bearing age were performed laparoscopic LPD nodules removal, 1 case gone combined with laparotomy and resecting LPD nodules; 2 cases in perimenopausal period done laparotomy oophorotomy and resected all LPD nodules and omentum. (3) Postoperative relapse and reproductive outcomes: the follow-up time of all cases was 2.8 years, and no recurrence was found during the follow-up period; 2 cases had natural conception and term vaginal birth during the follow-up period. Conclusions: LPD is mainly related to iatrogenic planting and spreading, which is a benign disease and characterized by multiple smooth muscle nodules throughout abdominopelvic cavity, and the nodules of LPD is commonly located in Douglas pouch, mesenteric and omentaum majus, etc. The preferred method of LPD should be individual operative treatment according to different situations, and in which patients may be have better prognosis.

Seroprevalence and risk factors for Toxoplasma gondii in sheep and goats in Jinzhou, Northeastern China

In the present study, serum samples from 402 sheep and 216 goats were collected from 5 counties in Jinzhou from August to October 2012 and antibodies to Toxoplasma gondii were detected by modified agglutination test (MAT). Overall, 104 (16.8%) had antibodies to T. gondii with antibody titres of 1:25 to 1:800. Seropositive samples were distributed in all the 5 counties and seroprevalences of T. gondii varied significantly with flock size, age and rearing system, but not with breed, gender and farm location. The seroprevalences in small farms (18.3%, 95/518, 95% confidence interval [CI], 15.0-21.7%) were statistically higher than that in large farms (9%, 9/100, 95% CI, 3.4-14.6%) (P < 0.05), older animals were statistically higher than that in younger animals (P < 0.01). The prevalence in extensively and semi intensively raised samples was statistically higher than that in intensively raised animals (P < 0.01). Small flock size and extensive rearing system are the potential risk factors for the prevalence of Toxoplasma infection in sheep and goats in Jinzhou. This is the first report of T. gondii infection in sheep and goats in Jinzhou, northeastern China, and of an association of seropositivity to T. gondii and the risk factors.

Polymorphisms and DNA methylation level in the CpG site of the GHR1 gene associated with mRNA expression, growth traits and hormone level of half-smooth tongue sole (Cynoglossus semilaevis)

The objectives of the present study were to estimate the GHR1 gene mutations and methylation status of CpGs, and whether those mutations and methylation were involved in the regulation of GHR1 gene expression, hormone level and growth traits in half-smooth tongue sole (Cynoglossus semilaevis). Identification of single-nucleotide polymorphisms was performed on 43 male fish. Through polymerase chain reaction-single-strand conformation polymorphism and sequencing, two SNPs were found. SNP1 [c.G1357A (p.Val376Ile)] creating one CpG site located in exon 8 was named L1 locus, and SNP2 (c.G1479A) located in exon 9 was named L2 locus. Individuals were divided into three genotypes, AA, AG and GG according to L1 locus (GG genotype had one more CpG site because of the mutation), and into two genotypes, AA- and GG-based on L2 locus. The results showed that only L1 locus was significantly associated with body weight (P < 0.01), gonad weight (P ≤ 0.05), triiodothyronine (T3) level (P ≤ 0.05) and mRNA expression (P < 0.01). At L1 locus, newly created CpG site in GG genotype was highly methylated (93.3 %), while there was no difference of methylation level in the other two CpG sites among three genotypes. AA genotype and AG genotype having higher T3 level were significantly different (P ≤ 0.05) from GG genotype. There were significant differences among body weights of AA, AG and GG genotypes (P < 0.01). Gonad weights of AA genotype and AG genotype were significantly lower than GG genotype. The GHR1 mRNA expression of GG genotype was significantly lower than AA and AG genotypes (P < 0.01). These implied that mutations and methylation status of GHR1 gene might influence the hormone level, growth traits and gene expression in male half-smooth tongue sole and the L1 locus could be regarded as a potential candidate genetic and epigenetic marker in half-smooth tongue sole selection.

Effects of zinc-methionine on growth performance, intestinal flora and immune function in pigeon squabs

1. Different concentrations of zinc-methionine (Zn-Met) were given to pigeon squabs, and the resulting effects on growth, immune functions and intestinal microflora were investigated from hatching to 28 d of age. A total of 180 artificially hatched pigeon squabs were randomly allotted to each of three treatments with three replicates of 20 squabs. The three treatments given were either one ml (2 mg/ml) Zn-Met, one ml (10 mg/ml) Zn-Met or one ml 0.9% NaCl solution. 2. The results showed that Zn-Met improved the growth performance of squabs. The average daily and average weekly weight gain was significantly greater in squabs treated with Zn-Met than in the control group. 3. The group given 2 and 10 mg supplemental Zn-Met had heavier thymus, spleen and bursa of Fabricius than the control group at d 28. 4. Maternal antibody titres against Newcastle disease haemagglutination inhibition and alpha-naphthyl acetate esterase were significantly higher in squabs treated with supplemental 2 and 10 mg Zn-Met compared to the control group at d 14 and d 28. 5. Additionally, the squabs given supplemental 2 mg Zn-Met exhibited significantly higher Bacillaceae, Lactobacillus, Enterococcus and Bifidobacterium populations at d 14 and d 28, but lower Escherichia coli populations at d 28 compared to the control group. On the contrary, Lactobacillus, Enterococcus and Bifidobacterium populations were significantly decreased with 10 mg Zn-Met at d 28. 6. This study indicates that supplementation with Zn-Met has a positive effect on growth performance, immune function and regulation of intestinal flora in pigeons. An inclusion level of 2 mg seems to be better than 10 mg Zn-Met per day per bird.

Increased glycophorin A somatic cell variant frequency in arsenic-exposed patients of Guizhou, China

Exposure to arsenic through domestic burning arsenic-containing coal causes various tumors in a population of Guizhou, China. The glycophorin A (GPA) assay is a human mutation assay detecting somatic variation in erythrocytes expressing the MN blood type, and was used to assess genotoxicity of arsenic-exposed patients. Peripheral blood was collected from 18 adult healthy subjects and 40 arsenic-exposed patients in heparin-treated tubes. Erythrocytes were isolated, fixed in formalin and immuno-labeled with fluorescent antibodies against GPA, followed by flow cytometry analysis. Arsenic exposure increased the variant frequency (expressed as the number of variant red cells per 10(6) erythrocytes): NN, 3.7 in healthy subjects versus 21.2 in arsenic-exposed patients; N phi, 12.6 versus 33.1; MM, 13.1 versus 110; and M phi, 5.2 versus 20.3. The total GPA variant frequency was increased about five-fold (34.7 in healthy subjects versus 185 in arsenosis patients). Furthermore, the variant frequency was significantly higher in skin tumor-bearing patients: NN, 19.4 in arsenic-exposed non-tumor patients versus 31.5 in tumor-bearing patients; N phi, 29.5 versus 54.5; MM, 102 versus 159; M phi, 15.9 versus 45.1. Total GPA variant frequency in arsenic-exposed patients bearing skin tumors was significantly increased compared to patients without skin tumors (167 versus 290). The relationship between arsenic exposure history and GPA variant frequency was less evident. These data demonstrate that arsenic exposure is associated with mutations at the GPA locus, an effect exaggerated in patients bearing arsenic-induced skin tumors. The variant frequency of GPA could be a useful biomarker for arsenic exposure and arsenic carcinogenesis.

[Experimental pharmacodynamic study on the anti-convulsion effect of shenpu decoction]

OBJECTIVE

To observe the anti-convulsion effect of Shenpu Decoction (SPD).

METHODS

Experiments were conducted in three acute convulsion models (cardiazol seizure, strychnine convulsion and maximal electrical shock). Models were divided into the control group (A, treated by normal saline), the high, middle and low dose SPD groups (B, C and D, treated with SPD 9 g/kg, 6 g/kg and 4 g/kg respectively), and the nitrazepam treated group (E). The anti-convulsion effect of SPD was evaluated by 50% convulsion dose (CD50) detected in each group.

RESULTS

In cardiazol convulsion model, the CD50 detected in group A-E were 63.3 +/- 3.4 mg/kg, 116.2 +/- 3.4 mg/kg, 105.6 +/- 3.7 mg/kg, 74.0 +/- 3.7 mg/kg and 197.2 +/- 3.3 mg/kg respectively, while they were 0.71 +/- 0.04 mg/kg, 1.21 +/- 0.04 mg/kg, 1.19 +/- 0.04 mg/kg, 0.94 +/- 0.04 mg/kg and 1.16 +/- 0.04 mg/kg respectively in the strychnine convulsion model, and 67.1 +/- 2.6 V, > 140 V, 109.4 +/- 3.5 V, 84.4 +/- 3.1 V and 128.4 +/- 3.9 V in the maximal electrical shock model respectively.

CONCLUSION

SPD has a good anticonvulsion effect.

Mast cells play a key role in neutrophil recruitment in experimental bullous pemphigoid

Bullous pemphigoid (BP) is an inflammatory subepidermal blistering disease associated with an IgG autoimmune response to the hemidesmosomal protein BP180. Passive transfer of antibodies to the murine BP180 (mBP180) ectodomain triggers a blistering skin disease in mice that depends on complement activation and neutrophil infiltration and closely mimics human BP. In the present study, we show that mast cells (MCs) play a crucial role in experimental BP. Wild-type mice injected intradermally with pathogenic anti-mBP180 IgG exhibited extensive MC degranulation in skin, which preceded neutrophil infiltration and subsequent subepidermal blistering. In contrast, mice genetically deficient in MCs or MC-sufficient mice pretreated with an inhibitor of MC degranulation failed to develop BP. Further, MC-deficient mice reconstituted in skin with MCs became susceptible to experimental BP. Despite the activation of complement to yield C3a and C5a, in the absence of MCs, accumulation of neutrophils at the injection site was blunted. The lack of response due to MC deficiency was overcome by intradermal administration of a neutrophil chemoattractant, IL-8, or by reconstitution of the injection sites with neutrophils. These findings provide the first direct evidence to our knowledge that MCs play an essential role in neutrophil recruitment during subepidermal blister formation in experimental BP.

Expression of inducible nitric oxide synthase and nitrotyrosine in multiple sclerosis lesions

Nitric oxide generated by the inducible form of nitric oxide synthase (iNOS) may contribute to the pathogenesis of multiple sclerosis (MS). In this report, we studied postmortem tissues of MS patients for the expression of iNOS by in situ hybridization and immunocytochemistry. Immunocytochemistry for nitrotyrosine, a putative footprint for peroxynitrite formation was also performed. In acute MS lesions, intense reactivity for iNOS mRNA and protein was detected in reactive astrocytes throughout the lesion and in adjacent normal appearing white matter. Staining of macrophages, inflammatory cell infiltrates, and endothelial cells was variable from case to case, but generally detected only in acute lesions. In chronic MS lesions reactive astrocytes at the lesion edge were positive for iNOS whereas the lesion center was nonreactive. Normal appearing white matter demonstrated little reactivity, as did tissues from noninflamed control brains. Staining for nitrotyrosine was also detected in acute but not chronic MS lesions, and displayed a diffuse parenchymal, membranous, and perivascular pattern of immunoreactivity. These results support the conclusion that iNOS is induced in multiple cell types in MS lesions and that astrocyte-derived nitric oxide could be important in orchestrating inflammatory responses in MS, particularly at the blood-brain barrier.

Expression of inducible nitric oxide synthase, interleukin-1 and caspase-1 in HIV-1 encephalitis

Inflammatory cytokines and enzymes such as IL-1 and inducible nitric oxide synthase (iNOS) may play an important role in the pathogenesis of AIDS dementia, a condition associated with infection of the CNS cells by the HIV-1. In this report, we investigated the expression of iNOS, IL-1, and caspase-1 (interleukin-1 converting enzyme) in HIV-1 encephalitis (HIVE) by immunocytochemistry and analyzed their expression with respect to HIV-1 infection and glial activation. In HIVE, all three molecules were expressed at high levels in areas of HIV-1 infection (microglial nodules with HIV-1 p24 immunoreactivity) and in areas of diffuse white matter gliosis. Expression was cell-type specific, with IL-1 and caspase-1 being expressed in macrophages and microglia, and iNOS in activated astrocytes. Multinucleated giant cells, a hallmark of virally infected cells, showed intense staining for both IL-1 and caspase-1, suggesting induction of these molecules by HIV-1. Double immunocytochemistry demonstrated a regional co-localization of astrocyte iNOS and microglial IL-1 and caspase-1. These results support the notion that autocrine and paracrine interactions between HIV-1 infected macrophages and microglia, activated microglia, and astrocytes lead to expression of proinflammatory and neurotoxic molecules. iNOS and caspase-1 may provide additional therapeutic targets for HIVE.

Regulation of experimental autoimmune encephalomyelitis in the C57BL/6J mouse by NK1.1+, DX5+, alpha beta+ T cells

C57BL/6 (B6) mice with targeted mutations of immune function genes were used to investigate the mechanism of recovery from experimental autoimmune encephalomyelitis (EAE). The acute phase of passive EAE in the B6 mouse is normally resolved by partial recovery followed by mild sporadic relapses. B6 TCR beta-chain knockout (KO) recipients of a myelin oligodendrocyte glycoprotein p35-55 encephalitogenic T cell line failed to recover from the acute phase of passive EAE. In comparison with wild-type mice, active disease was more severe in beta(2)-microglobulin KO mice. Reconstitution of TCR beta-chain KO mice with wild-type spleen cells halted progression of disease and favored recovery. Spleen cells from T cell-deficient mice, IL-7R KO mice, or IFN-gamma KO mice were ineffective in this regard. Irradiation or treatment of wild-type spleen cell population with anti-NK1.1 mAb before transfer abrogated the protective effect. Removal of DX5(+) cells from wild-type spleen cells by anti-DX5 Ab-coated magnetic beads before reconstitution abrogated the suppressive properties of the spleen cells. TCR-deficient recipients of the enriched DX5(+) cell population recovered normally from passively induced acute disease. DX5(+) cells were sorted by FACS into DX5(+) alpha beta TCR(+) and DX5(+) alpha beta TCR(-) populations. Only recipients of the former recovered normally from clinical disease. These results indicate that recovery from acute EAE is an active process that requires NK1.1(+), DX5(+) alpha beta(+) TCR spleen cells and IFN-gamma.

Cryptococcus neoformans induces macrophage inflammatory protein 1alpha (MIP-1alpha) and MIP-1beta in human microglia: role of specific antibody and soluble capsular polysaccharide

We characterized the expression of the beta-chemokines macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and RANTES by primary human microglia after exposure to Cryptococcus neoformans. In the absence of specific antibody, C. neoformans failed to elicit a chemokine response, while in the presence of specific antibody, microglia produced MIP-1alpha and MIP-1beta in amounts comparable to those induced by lipopolysaccharide. RANTES was also induced but at much lower levels. In addition to MIP-1alpha and MIP-1beta mRNA, we observed a robust induction of monocyte chemoattractant protein 1 and interleukin-8 mRNA following incubation of microglia with opsonized C. neoformans. In contrast, cryptococcal polysaccharide did not induce a chemokine response even when specific antibody was present and inhibited the MIP-1alpha induction associated with antibody-mediated phagocytosis of C. neoformans. The role of the Fc receptor in the observed chemokine induction was explored in several experiments. Treatment of microglia with cytochalasin D inhibited internalization of C. neoformans but did not affect MIP-1alpha induction. In contrast, treatment with herbimycin A, a tyrosine kinase inhibitor, inhibited MIP-1alpha induction. Microglia stimulated with immobilized murine immunoglobulin also produced MIP-1alpha and RANTES (MIP-1alpha > RANTES). Our results show that microglia produce several chemokines when stimulated by C. neoformans in the presence of specific antibody and that this process is likely to be mediated by Fc receptor activation. This response can be down-regulated by cryptococcal capsular polysaccharide. These findings suggest a mechanism by which C. neoformans infections fail to induce strong inflammatory responses in patients with cryptococcal meningoencephalitis and have important implications for antibody therapy.

Role of MIP-1beta and RANTES in HIV-1 infection of microglia: inhibition of infection and induction by IFNbeta

Microglia are the major target of HIV-1 infection in the brain. Microglial infection is CD4-dependent, but the role of chemokine receptors CCR5 and CCR3 and their natural ligands in modulating HIV-1 infection in microglia has been questioned. In primary human fetal microglial cultures, we demonstrate that HIV-1 infection of these cells is dependent on CCR5, since an antibody to CCR5 completely blocked productive infection. Anti-CCR3, in contrast, had a smaller inhibitory effect which was not statistically significant. The chemokine ligands for CCR5, RANTES and MIP-1beta, also potently inhibited HIV-1 infection in microglia, but the third ligand MIP-1alpha failed to show inhibition. Interestingly, when microglial cultures were treated with antibodies specific to each of these chemokines, HIV-1 infection was enhanced by anti-RANTES and anti-MIP-1beta, but not by anti-MIP-1alpha. These results demonstrate the presence of endogenous chemokines that act as endogenous inhibitors of HIV-1 infection in microglia. Additionally, IFNbeta, a known anti-viral cytokine, also provided potent inhibition of viral infection as well as induction of all three chemokines in microglia. These results suggest the possibility that type I interferon can down-modulate microglial HIV-1 infection in vivo by multiple mechanisms.

The fate of adoptively transferred quiescent encephalitogenic T cells in normal and antigen-tolerized mice

Adoptive transfer of quiescent encephalitogenic T cells to normal syngeneic recipients was without clinical effect. RT-PCR was used to assess localization of an adoptively transferred quiescent encephalitogenic T cell clone in normal and antigen-unresponsive mice prior to or after challenge with neuroantigen/CFA. The T cell clone was not detectable in lymphoid tissues prior to challenge with neuroantigen; however, following challenge, the clone was found in the spleen, lymph nodes and spinal cord of both normal and antigen-tolerized mice. The latter animals remained clinically normal. Non-activated encephalitogenic T cells transferred to wild-type recipients pretreated i.p. with neuroantigen/IFA were rendered unresponsive. Transfer of the same T cells to alpha/beta T cell-deficient mice pretreated with neuroantigen/IFA resulted in spontaneous disease indicating that an intact alpha/beta T cell system was required for development of the unresponsive state.

Alterations in the spinal cord T cell repertoire during relapsing experimental autoimmune encephalomyelitis

The CNS T cell repertoire was analyzed by RT-PCR, spectratyping, and nucleotide sequencing of the amplified products at different times following adoptive transfer of a CD4+, Th1, VB2+ encephalitogenic SJL/J proteolipid protein peptide 139-151-specific T cell clone. The third complementarity-determining region of TCR B chains in the spinal cord was used as an indicator of T cell heterogeneity. Spectratypic analysis revealed that a single peak corresponding to the third complementarity-determining region of the initiating T cell clone predominated during the acute phase. During recovery and relapse the complexity of the spectratype increased. DNA sequence analysis revealed that the donor clone predominated at the acute phase. By the first relapse the donor clone, although represented most frequently, was a minority of the total. Spectratypic analysis of the same samples for several other VB families revealed their presence during acute disease or relapses but, with the exception of VB17, their absence during the recovery stage.

A novel microtubule-associated protein-2 expressed in oligodendrocytes in multiple sclerosis lesions

Elucidation of the mechanisms involved in the regeneration of oligodendrocytes and remyelination is a central issue in multiple sclerosis (MS) research. We recently identified a novel alternatively spliced, developmentally regulated oligodendrocyte-specific protein designated microtubule-associated protein-2+13 [microtubule-associated protein-2 expressing exon 13 (MAP-2+13)]. MAP-2+13 is expressed in human fetal oligodendrocytes during process extension and myelination but is minimally expressed in normal mature CNS. To test the hypothesis that MAP-2+13 is reexpressed in regenerating oligodendrocytes in MS lesions, we examined the brains of MS patients for the expression of this protein. By immunocytochemistry using a series of monoclonal antibodies specific for MAP-2+13, we determined that MAP-2+13 expression was up-regulated in all 31 lesions from 10 different MS brains. MAP-2+13 was expressed in regenerating oligodendrocytes associated with demyelinated lesions, with the highest counts found in regions of extensive remyelination. By electron microscopy, MAP-2+13 was localized to oligodendrocytes engaged in remyelination, evident by their process extension and association with thinly myelinated (remyelinated) and demyelinated axons. These results suggest a hitherto unsuspected role for this microtubule-associated protein in oligodendrocyte function during development and myelin repair.

Neuronal death in cytokine-activated primary human brain cell culture: role of tumor necrosis factor-alpha

We examined cytokine-mediated neuronal death in neuron-astrocyte cultures from second trimester human fetal cerebrum. In these cultures, high-output inducible nitric oxide synthase (NOS) and tumor necrosis factor-alpha (TNFalpha) are expressed in astrocytes after exposure to IL-1beta/IFNgamma. Neuronal cell death was evident at >/=48 h following cytokine stimulation. Neutralizing anti-TNFalpha antiserum inhibited ( approximately 48%) neurotoxicity in IL-1beta/IFNgamma-treated cultures, demonstrating a role for endogenously produced TNFalpha. Interestingly, the degree of neuroprotection conferred by superoxide dismutase or N-methyl D-aspartate (NMDA) receptor antagonists in these cultures was smaller and variable. Similarly, the effect of the NOS inhibitor, N(G)-monomethyl L-arginine (NMMA) on IL-1beta/IFNgamma-induced neuronal death was variable, showing no statistically significant effect when results from more than 30 independent cultures were averaged. Neurons die by apoptosis in cytokine-treated human fetal CNS cultures as shown by the characteristic nuclear morphology as well as positive labeling for TUNEL. Our results demonstrate a potent neurotoxicity mediated by the cytokine combination IL-1beta/IFNgamma in primary human neuron-astrocyte cultures and a crucial role for endogenous TNFalpha in mediating neurotoxicity in this system. These results firmly establish the neurotoxic potential of the inflammatory cytokines IL-1beta and TNFalpha in the human CNS.

Inducible nitric oxide synthase immunoreactivity in the Alzheimer disease hippocampus: association with Hirano bodies, neurofibrillary tangles, and senile plaques

Inducible nitric oxide synthase (iNOS) is involved in the generation of nitric oxide, a molecule with multiple biological activities. Although iNOS expression may be part of antimicrobial armamentarium, inappropriate expression of iNOS can potentially lead to damage to the host. In this report, we determined the expression of iNOS by immunocytochemistry in the hippocampus of the Alzheimer brains (AD) as well as in young and old normal brains. The results showed localization of iNOS immunoreactivity to Hirano bodies of the AD hippocampus. In addition, small granular iNOS immunoreactive profiles were detected associated with senile plaques and extracellular neurofibrillary tangles. In the hippocampus of control brains, morphologically similar profiles were immunoreactive for iNOS, but in far fewer numbers than in AD hippocampus. The results suggest that iNOS is expressed in a subset of pyramidal neurons in the AD hippocampus, and that iNOS may be involved in the pathogenesis of neuronal degeneration in AD.

Neuronal nitric oxide synthase expression in developing and adult human CNS

Neuronal nitric oxide synthase (nNOS) is constitutively expressed by subpopulations of neurons in the CNS and is involved in neurotransmission, learning and memory, and neuronal injury. While the distribution of nNOS neurons has been characterized in the rodent CNS, the expression in human brain has not been well documented. We determined the expression of nNOS in second trimester human fetal and adult brain. In second trimester fetal brain, the nNOS neurons are concentrated in the developing cerebral cortex at the subplate zone and in layer VI, the striatum, and in certain brainstem nuclei. The nNOS neurons are sparsely distributed in the hippocampus, and virtually absent in the cerebellar cortex. The nNOS neurons in the subplate zone extend their processes radially, suggesting a developmental role, perhaps in guidance. The number and distribution of NADPH diaphorase-positive neurons corresponds to that of the nNOS neurons. While the distribution of nNOS neurons in the adult brain is similar to that found in fetal brain, the overall density is lower in the adult. The highest density of nNOS neurons is found in the striatum followed by the neocortex. A region-specific role for nNOS neurons in human brain and a potential developmental role for nNOS in the cerebral cortex are suggested by these data.

Pathogenesis of acute passive murine encephalomyelitis II. Th1 phenotype of the inducing population is not sufficient to cause disease

The present study was designed to assess the pattern of cytokine expression over the course of disease in the central nervous system (CNS) of recipients of an encephalitogenic T-cell clone specific for proteolipid protein (PLP) peptide 139-151. Reverse transcriptase-polymerase chain reaction (RT-PCR) analyses of CNS mRNA from samples taken during the onset of acute disease demonstrated upregulation of message for cytokines involved in the recruitment and activation of macrophages (GM-CSF, interleukin (IL)-3, IL-9) and the inflammatory cytokines tumor necrosis factor (TNF)-alpha and iNOS as well as message for IL-10 and transforming growth factor (TGF)beta. During the recovery stage message for most cytokines was absent, but during relapse inflammatory cytokine messages were again detectable. Message for the accessory molecules B7-2 and CTLA-4 was observed only on the day of onset of acute experimental allergic encephalomyelitis (EAE) and at relapse. The messages for these molecules were downregulated at the onset of recovery. These results illustrate the dynamic nature of the immune response during the course of EAE, and support a model of disease in which T-cells are involved in the regulation of disease while a nonspecific inflammatory reaction is responsible for the CNS damage observed during EAE.

Inducible nitric oxide synthase expression is selectively induced in astrocytes isolated from adult human brain

Inducible nitric oxide synthase (iNOS) expression has been shown to be differentially regulated among different cell types and species. In cultures of primary human fetal glial cells, we have shown that astrocytes rather than microglia express iNOS. In the present study, we extended these findings to primary cultures of astrocytes and microglia derived from adult human brains. Mixed cultures of adult brain tissue were stimulated with IL-1beta and IFNgamma, a combination known to induce iNOS maximally in human fetal cells, and the expression of iNOS was determined by immunocytochemistry. Cell types were determined by morphology as well as immunocytochemistry for GFAP (astrocytes) and CD68 (microglia). The results showed that in cultures of adult human glia, iNOS was expressed following stimulation with cytokines, and the expression was restricted to astrocytes. Astrocyte iNOS immunoreactivity was detected both in the cytosol and in a discrete paranuclear region, a pattern noted in human fetal astrocytes. These results demonstrate that the ability to express iNOS is common to both fetal and adult human astrocytes.

Persistence of an encephalitogenic T cell clone in the spinal cord during chronic, relapsing experimental autoimmune encephalomyelitis

The CDR3 region of the TCR beta-chain of a CD4+, Th1, Vbeta2+ encephalitogenic T cell clone was used as an idiotypic marker to track the location of the clone in vivo. cDNA prepared from the spinal cord, thymus, lymph nodes, spleen, and liver of the recipients at various stages of EAE was amplified using Vbeta2 and Cbeta-region primers, and the products immobilized. The membrane was probed with a 32P-labeled oligonucleotide complementary to the CDR3 region of the T cell clone. The probe reacted strongly with products from the spinal cord, spleen and liver and less strongly with products from lymph nodes and thymus of mice with acute EAE. The signal was greatly diminished in the spinal cord and other tissues during recovery from acute disease and reappeared in the spinal cord at each relapse.

Acute and relapsing experimental autoimmune encephalomyelitis in IL-4- and alpha/beta T cell-deficient C57BL/6 mice

Experimental autoimmune encephalomyelitis follows a chronic relapsing course in several inbred strains of mice. To address the role of T cells in recovery and relapse, the clinical course of EAE was compared in C57BL/6 (B6) normal and immunodeficient mice following active immunization with MOG p35-55 or adoptive transfer of encephalitogenic peptide-specific T cell lines. The course of actively-induced EAE in B6 wild-type and IL-4 -/- mice was similar. B6 IL-4 -/- mice recovered normally from acute passive EAE, but did not relapse in contrast to wild-type B6 mice. EAE was progressive in B6 RAG -/- and alpha/beta TCR -/- mice, but the disease course could be arrested by infusion of normal spleen cells. When non-activated MOG peptide-specific T cells were transferred to wild-type or alpha/beta TCR -/- mice, spontaneous disease ensued in the mutants only.

Pathogenesis of acute passive murine encephalomyelitis I. Importance of host-derived cells as determined by kinetic analysis

Kinetics of entry into the CNS of donor- and host-derived T-cells during the onset of acute murine EAE induced by the passive transfer of an encephalitogenic PLP(139-151)-specific T-cell clone was investigated. RT-PCR and spectratypic analysis of total RNA recovered from recipient mice demonstrated the presence in the CNS of donor- and host-derived T-cells 24 h post adoptive transfer. Donor-derived T-cells detected in the CNS decreased days 2-6 post transfer while host-derived T-cells persisted during this time. Beginning 3 days before clinical onset, an increase in the CNS of both T-cell populations was observed which persisted through disease onset. Similar analysis performed on recipients of an nonencephalitogenic PLP(139-151)-specific T-clone demonstrated a transient infiltration of donor- and host-derived T-cells beginning 4 days post transfer (dpt) and returning to background levels by day 7 post transfer. Results presented here suggest the importance of host-derived T-cells in the onset of acute passive murine EAE.

Alterations in frequency coding and activity dependence of excitability in cultured neurons of Drosophila memory mutants

Mutants of the Drosophila dunce (dnc) and rutabaga (rut) genes, which encode a cAMP-specific phosphodiesterase and a calcium/calmodulin-responsive adenylyl cyclase, respectively, are deficient in short-term memory. Altered synaptic plasticity has been demonstrated at neuromuscular junctions in these mutants, but little is known about how their central neurons are affected. We examined this problem by using the "giant" neuron culture, which offers a unique opportunity to analyze mutational effects on neuronal activity and the underlying ionic currents in Drosophila. On the basis of instantaneous frequency and first latency of spikes evoked by current steps, four categories of firing patterns (tonic, adaptive, delayed, and interrupted) were identified in wild-type neurons, revealing interesting parallels to those commonly observed in vertebrate CNS neurons. The distinct firing patterns were correlated with expression of different ratios of 4-aminopyridine- and tetraethylammonium-sensitive K+ currents. Subsets of dnc and rut neurons displayed abnormal spontaneous spikes and altered firing patterns. Altered frequency coding in mutant neurons was demonstrated further by using stimulation protocols involving conditioning with previous activity. Abnormal spike activity and reduced K+ current remained in double-mutant neurons, suggesting that the opposite effects on cAMP metabolism by dnc and rut do not counterbalance the mutual functional defects. The aberrant spontaneous activity and altered frequency coding in different stimulus paradigms may present problems in the stability and reliability of neural circuits for information processing during certain behavioral tasks, raising the possibility of modulation in neuronal excitability as a cellular mechanism underlying learning and memory.

Thymic expression of myelin basic protein (MBP). Activation of MBP-specific T cells by thymic cells in the absence of exogenous MBP

Previous studies have shown golli-myelin basic protein (MBP) mRNA to be expressed in the thymus of normal SJL mice, but translation of the mRNA was not assessed. To test for the presence of immunoreactive protein, single cell suspensions were prepared from adult SJL thymus and cultured with syngeneic MBP-specific T cells. After 48 h [3H]thymidine was added to the microcultures to assess T cell proliferation. MBP-specific T cell lines proliferated strongly (stimulation index range, 13-31). T cell lines specific for MBP exon 2, MBP peptide 89-101, proteolipid protein peptide 139-151, and OVA gave stimulation indices of 10-13, 5-6, 2-3, and 2-3, respectively. Stimulatory activity could be abrogated by irradiation of either the thymic cells or the MBP-specific T cells. Stimulatory activity was a property of a minor population of plastic-adherent thymic cells. Monoclonal anti-I-As Ab added to the microcultures inhibited the reaction by 77%. MBP-specific T cells cultured with syngeneic nonirradiated thymus cells in the absence of added MBP transferred experimental autoimmune encephalomyelitis adoptively to syngeneic recipients. These findings indicate that golli-MBP mRNA is translated in normal SJL thymus, and that peptides reactive with MBP-specific T cells in the context of class II MHC molecules are expressed.

Thymic expression of myelin basic protein (MBP). Activation of MBP-specific T cells by thymic cells in the absence of exogenous MBP

Previous studies have shown golli-myelin basic protein (MBP) mRNA to be expressed in the thymus of normal SJL mice, but translation of the mRNA was not assessed. To test for the presence of immunoreactive protein, single cell suspensions were prepared from adult SJL thymus and cultured with syngeneic MBP-specific T cells. After 48 h [3H]thymidine was added to the microcultures to assess T cell proliferation. MBP-specific T cell lines proliferated strongly (stimulation index range, 13-31). T cell lines specific for MBP exon 2, MBP peptide 89-101, proteolipid protein peptide 139-151, and OVA gave stimulation indices of 10-13, 5-6, 2-3, and 2-3, respectively. Stimulatory activity could be abrogated by irradiation of either the thymic cells or the MBP-specific T cells. Stimulatory activity was a property of a minor population of plastic-adherent thymic cells. Monoclonal anti-I-As Ab added to the microcultures inhibited the reaction by 77%. MBP-specific T cells cultured with syngeneic nonirradiated thymus cells in the absence of added MBP transferred experimental autoimmune encephalomyelitis adoptively to syngeneic recipients. These findings indicate that golli-MBP mRNA is translated in normal SJL thymus, and that peptides reactive with MBP-specific T cells in the context of class II MHC molecules are expressed.

Expression of type II nitric oxide synthase in primary human astrocytes and microglia: role of IL-1beta and IL-1 receptor antagonist

In this work, we studied the expression of type II nitric oxide synthase (NOS) in primary cultures of human astrocytes and microglia. Cytokine-activated human fetal astrocytes expressed a 4.5-kb type II NOS mRNA that was first evident at 8 h, steadily increased through 48 h, and persisted through 72 h. The inducing signals for astrocyte NOS II mRNA expression were in the order IL-1beta + IFN-gamma > IL-1beta + TNF-alpha > IL-1beta. SDS-PAGE analysis of cytokine-stimulated astrocyte cultures revealed an approximately 130-kDa single NOS II band that was expressed strongly at 48 and 72 h (72 h > 48 h). Specific NOS II immunoreactivity was detected in cytokine-treated astrocytes, both in the cytosol and in a discrete paranuclear region, which corresponded to Golgi-like membranes on immunoelectron microscopy. In human microglia, cytokines and LPS failed to induce NOS II expression, while the same stimuli readily induced TNF-alpha expression. In cytokine-treated human astrocytes, neither NOS II mRNA/protein expression nor nitrite production was inhibited by TGF-beta, IL-4, or IL-10. In contrast, IL-1 receptor antagonist exerted near complete inhibition of NOS II mRNA and nitrite induction. Monocyte chemoattractant peptide-1 mRNA was induced in TGF-beta-treated astrocytes, demonstrating the presence of receptors for TGF-beta in astrocytes. These results confirm that in humans, cytokines stimulate astrocytes, but not microglia, to express NOS II belonging to the high output nitric oxide system similar to that found in rodent macrophages. They also show that the regulation of type II NOS expression in human glia differs significantly from that in rodent glia. A crucial role for the IL-1 pathway in the regulation of human astrocyte NOS II is shown, suggesting a potential role for IL-1 as a regulator of astrocyte activation in vivo.

Expression of type II nitric oxide synthase in primary human astrocytes and microglia: role of IL-1beta and IL-1 receptor antagonist

In this work, we studied the expression of type II nitric oxide synthase (NOS) in primary cultures of human astrocytes and microglia. Cytokine-activated human fetal astrocytes expressed a 4.5-kb type II NOS mRNA that was first evident at 8 h, steadily increased through 48 h, and persisted through 72 h. The inducing signals for astrocyte NOS II mRNA expression were in the order IL-1beta + IFN-gamma &gt; IL-1beta + TNF-alpha &gt; IL-1beta. SDS-PAGE analysis of cytokine-stimulated astrocyte cultures revealed an approximately 130-kDa single NOS II band that was expressed strongly at 48 and 72 h (72 h &gt; 48 h). Specific NOS II immunoreactivity was detected in cytokine-treated astrocytes, both in the cytosol and in a discrete paranuclear region, which corresponded to Golgi-like membranes on immunoelectron microscopy. In human microglia, cytokines and LPS failed to induce NOS II expression, while the same stimuli readily induced TNF-alpha expression. In cytokine-treated human astrocytes, neither NOS II mRNA/protein expression nor nitrite production was inhibited by TGF-beta, IL-4, or IL-10. In contrast, IL-1 receptor antagonist exerted near complete inhibition of NOS II mRNA and nitrite induction. Monocyte chemoattractant peptide-1 mRNA was induced in TGF-beta-treated astrocytes, demonstrating the presence of receptors for TGF-beta in astrocytes. These results confirm that in humans, cytokines stimulate astrocytes, but not microglia, to express NOS II belonging to the high output nitric oxide system similar to that found in rodent macrophages. They also show that the regulation of type II NOS expression in human glia differs significantly from that in rodent glia. A crucial role for the IL-1 pathway in the regulation of human astrocyte NOS II is shown, suggesting a potential role for IL-1 as a regulator of astrocyte activation in vivo.

Active and passive experimental autoimmune encephalomyelitis in strain 129/J (H-2b) mice

Failure of C57BL/6J and C57BL/10Sn (H-2b) mice to exhibit clinical signs of experimental autoimmune encephalomyelitis following immunization with myelin basic protein (MBP) has been interpreted to indicate that mice of this haplotype are resistant to EAE. Recently, we immunized strain 129/J (H-2b) mice with rat MBP and found that clinical signs of EAE were expressed in the majority of animals within 2 to 3 weeks. Passive EAE was readily induced by adoptive transfer of MBP-specific T cell lines to syngeneic recipients. MBP peptide 89-101 and PLP peptide 178-191 induced EAE upon active immunization although proteolipid protein peptide 139-151 was ineffective in this regard. Strain 129/J mice never recovered fully from acute EAE, and signs of relapsing disease were not observed.

Cryptococcus neoformans survive and replicate in human microglia

BACKGROUND

Cryptococcus neoformans (CN) is an opportunistic pathogen that can cause fatal meningoencephalitis in patients with immune deficiency. Among the central nervous system (CNS) cells that are infected by CN are perivascular microglia and macrophages. Little is known about the interaction of CN and CNS phagocytes at the cellular level.

EXPERIMENTAL DESIGN

To better understand the fate of CN in microglia, we followed Ab-opsonized CN in human fetal microglial culture by phase-contrast microscopy, combined lighted microscopy and transmission electron microscopy of plastic-embedded monolayers, and immunocytochemistry for localization of capsular Ag.

RESULTS

Phase-contrast microscopy revealed that microglia initially internalized and contained Ab-opsonized yeast cells within phagolysosomes. However, CN escaped from microglia and resumed extracellular growth 16 to 24 hours after being phagocytosed. Transmission electron microscopy/1-mu epoxy sections revealed that intracellular CN were localized in two types of phagosomes in microglia: spacious phagosomes (SP) and close-fitting phagosomes (CP). Three lines of evidence indicate that SP are the primary sites for intracellular CN survival and replication: (a) SP contained multiple, budding yeast cells, whereas CP contained only single yeast cells within a tightly bound phagosomal membrane; (b) the number of SP and the number of CN within SP increased considerably at 24 hours compared with at 2 hours; and (c) microglial cultures challenged with heat- or amphotericin B-treated CN had significantly fewer SP than those challenged with live CN. Both SP and CP phagosomes fused with lysosomes, suggesting that CN survival in SP was not due to failure of phagolysosomal fusion. In SP, there was attenuation and diffusion of capsular polysaccharide within the phagosome, whereas in CP the fungal capsules remained compact and homogeneous. Immunocytochemistry with an mAb directed to capsular glucoronoxylomannan supported continued synthesis of polysaccharide within SP.

CONCLUSION

The results suggest that, in human microglia, CN survive and replicate within SP. Modification of CN capsular polysaccharide within SP may be a contributing factor to this aberrant microglial-CN interaction.

The immune response to a subdominant epitope in myelin basic protein exon-2 results in immunity to intra- and intermolecular dominant epitopes

Experimental autoimmune encephalomyelitis was induced in SJL/J mice by adoptive transfer of a MBP exon-2 peptide-specific T cell line. The T cell line, when tested for antigen specificity, reacted strongly with exon-2 peptide, but not with MBP peptides pAc1-11, p43-88, p89-101 or PLP p139-151. The specificity of splenic or lymph node T cells isolated from mice with acute or first relapse EAE induced by adoptive transfer of the exon-2-specific T cell line was identical to the transferred line. Splenocytes or lymphocytes isolated from mice at the second relapse were reactive with MBP p43-88, p89-101 and PLP p139-151 in addition to exon-2 peptide and MBP peptide Ac1-11. T cell lines selected by culture with MBP exon-2 peptide or PLP p139-151 from splenic cells from mice with relapsing EAE were weakly encephalitogenic; however, T cell lines selected from the same mice with MBP pAc1-11 were not encephalitogenic. T cells from the exon-2 and p139-151 T cell lines primed recipients for rapid onset severe EAE, whereas the pAc1-11 T cell line did not. T cells from the exon-2-specific line did not express V beta 17a+ TCR; however, peptide-specific T cell lines derived from the spleens of relapsing animals did express this TCR gene segment providing direct evidence of recruitment and sensitization of recipient T cells.

Functional expression of Shaker K+ channels in cultured Drosophila "giant" neurons derived from Sh cDNA transformants: distinct properties, distribution, and turnover

Expression of transgenic Shaker (Sh) channels has not previously been examined in Drosophila neurons. We studied K+ current by whole-cell recording in cultured "giant" neurons derived from germline transformants. Independent lines were generated by using a P-element vector, in which transcription of the 29-4 cDNA, one of the Sh splicing variants (Iverson and Rudy, 1990), was under the control of a heat shock (HS)-inducible promoter. Transformants in wild-type and two different Sh mutant backgrounds all exhibited an HS-inducible, A-type K+ current that was characterized by a much slower recovery from inactivation and a higher sensitivity to 4-aminopyridine than native K+ currents of Sh 29-4 currents expressed in Xenopus oocytes. Despite similarities in the kinetic and pharmacological properties of the HS-induced current in all backgrounds examined, host-dependent differences in the peak current amplitude have been consistently observed between multiple lines of 29-4 ShM and 29-4 Sh120 that might reflect differential channel subunit assembly in different hosts. Isolation of the novel 29-4 currents allowed determination of the channel turnover rate in cultured neurons. These currents persisted for up to 3 d or more, comparable with the durations previously reported for Na+ and Ca2+ channels. Surprisingly, the percentage of cells expressing inactivating K+ currents remained approximately the same with or without HS induction, suggesting that some mechanisms exist to restrict functional expression of inactivating K+ channels, including transgenic Sh channels and those not encoded by the Sh locus, to certain types of neurons.

Cytoskeletal alterations in human fetal astrocytes induced by interleukin-1 beta

Previous studies in this and other laboratories have shown that interleukin-1 beta (IL-1 beta) is a selective and potent activator of human astrocytes with respect to induction of cytokines and hematopoietic growth factors. To study the effect of recombinant human IL-1 beta (rhIL-1 beta) on astrocyte morphology, glial fibrillary acidic protein (GFAP) and vimentin expression, and actin organization, we conducted a systematic survey using dissociated human fetal astrocyte cultures. Within hours of stimulation with IL-1 beta, the majority of astrocytes converted from flat, polygonal cells to small, contracted, highly branched cells. This change in morphology was more striking when serum was eliminated from the medium. Complete dissolution of filamentous actin occurred simultaneously with the change in cell shape, as demonstrated by fluorescein-phalloidin binding. These "activated" astrocytes displayed intense GFAP and vimentin immunoreactivity in the small perikarya and processes. In contrast, the large, flat astrocytes in control cultures showed diffuse pale immunoreactivity for GFAP and vimentin. To quantify the changes in GFAP and vimentin content with IL-1 beta stimulation, densitometric analyses of northern and western blots were performed. Northern blot analysis of IL-1 beta-stimulated astrocytes revealed a transient, marked decrease in steady-state levels of mRNA for GFAP, vimentin, and microtubule-associated protein 4. The decrease in mRNA levels was evident by 4-8 h and fell to the lowest level at 16-24 h (80-98% decrease by densitometry) with partial recovery by 72 h. By immunoblotting, a significant decrease in both GFAP and vimentin protein content was observed after IL-1 beta stimulation. Furthermore, metabolic labeling studies revealed an almost total loss of GFAP synthesis following stimulation with IL-1 beta for 16 h. These observations are consistent with the idea that increases in immunoreactivity were related to factors such as redistribution of epitope, rather than increases in total protein content. We hypothesize that in IL-1 beta-stimulated astrocytes, synthesis of other proteins, e.g., inflammatory cytokines, occurs at the expense of structural proteins and that the decrease in content of cytoskeletal proteins may reflect an "activated" state of astrocytes.

Encephalitogenicity of myelin basic protein exon-2 peptide in mice

Immunization with a synthetic peptide with an amino acid sequence corresponding to mouse myelin basic protein exon-2 induced mild experimental allergic encephalitis (EAE) in B10.RIII mice, very mild disease in SJL/J mice and no disease in (SJL x PL)F1 hybrid mice. In contrast, adoptive transfer of an exon-2 peptide-specific T cell line from SJL mice induced severe relapsing EAE in syngeneic recipients. The T cell line was specific for exon-2 peptide and did not cross-react appreciably with an MBP preparation consisting of the 18.5 and 14-kDa isoforms. mRNA for exon-2 containing isoforms could be demonstrated in the spinal cord of SJL/J and B10.RIII mice by amplification using exon-2 and exon-4 oligonucleotide primers. On a relative basis, the level of exon-2 cDNA was lower than that of exon-1 cDNA in the same spinal cord preparations from both strains of mice.

Immunoreactivity profile of hippocampal CA2/3 neurites in diffuse Lewy body disease

Ubiquitin-immunoreactive dystrophic neurites in the CA2/3 region of the hippocampus are characteristic of diffuse Lewy body disease (DLBD). The origin of dystrophic CA2/3 neurites is unknown, but their extent correlates with the number of cortical Lewy bodies (LBs). To examine the molecular composition of these lesions, hippocampal sections were obtained at postmortem from cases of DLBD, Parkinson's disease and Alzheimer's disease. The tissue samples were fixed in a variety of fixatives and immunostained with antibodies to ubiquitin, ubiquitin C-terminal hydrolase (PGP9.5), neurofilament protein subunits, tau protein, paired helical filaments and tyrosine hydroxylase (TH). In addition to being ubiquitin positive, both cortical LBs and CA2/3 dystrophic neurites were positive with a neurofilament monoclonal antibody (RM032) and PGP9.5; however, fewer lesions were detected with these antibodies compared to ubiquitin immunocytochemistry. The dystrophic CA2/3 neurites were not stained with antibodies to tau proteins, paired helical filaments or TH. Absence of TH immunoreactivity suggests that CA2/3 neuritic processes are not derived from brain stem dopaminergic afferents to the hippocampus. Since CA2/3 neurites are immunologically similar to cortical LB, the pathogenesis of these lesions may be similar. Characterization of dystrophic CA2/3 neurites and cortical LBs may clarify how these lesions contribute to the emergence of dementia in DLBD.

Interleukin-3 and encephalitogenic activity of SJL/J myelin basic protein-specific T cell lines

Myelin basic protein (MBP)-specific SJL/J T cells were cultured in normal growth medium or growth medium supplemented with 10% culture supernatant from WEHI-3 cells, a source of interleukin-3 (IL-3), or with recombinant IL-3. T cell lines cultured with IL-3 supplementation were more encephalitogenic compared to parallel lines cultured without this supplement. There was little difference in antigen-specific proliferative response or expression of cell surface markers CD3, CD4, CD8, IL-2R, or alpha/beta TCR in the parallel lines. Supernatant fluids from antigen-stimulated T cells from each cycle were tested for the presence of IL-2, IL-3, IL-4, granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF alpha/beta) and transforming growth factor-beta (TGF beta). No significant difference in IL-2, IL-4, GM-CSF, TNF alpha/beta, or TGF beta levels were seen when supplemented and unsupplemented cultures were compared. Supernatant culture fluids contained an activity that was highly stimulatory for the IL-3-dependent mouse mast cell line, MC/9. This activity was attributable to a combination of at least three factors that varied in relative concentrations throughout the course of the experiments. Based on neutralization by monoclonal antibodies, MC/9 stimulating activity in early passage lines was attributable entirely to IL-3 and GM-CSF. The fraction of the MC/9 stimulatory activity that could be neutralized by monoclonal antibody to IL-3 decreased with increasing stimulation cycle while the fraction neutralized by anti-GM-CSF antibodies remained relatively constant. At the time that the lines lost encephalitogenicity, the activity neutralizable by anti-IL-3 had dropped to low levels in the culture supernatants; however, MC/9 stimulatory activity remained present in the supernatants. This was due to GM-CSF and a third unidentified factor.

Epitope specificity and TCR V beta gene utilization in the encephalitogenic response of B10.RIII(71NS)/SnJ mice

A high proportion of peptide 1-11 specific T cells from H-2u (V beta 8+, H-2u) mice express the V beta 8 TCR chain. Peptide 89-101 is immunodominant for B10.RIII (V beta 8+, H-2r) mice; thus, it was of interest to determine whether V beta 8 TCR would be over-represented in a population of peptide 89-101-specific T cells of this strain. Second, it was asked whether MBP peptides other than 89-101 would induce EAE in these mice. Of 70 B10.RIII(71NS)/SnJ mice immunized with mouse myelin basic protein (MBP), 32 of 41 males (78%) and 11 of 29 females (38%) showed clinical signs of experimental allergic encephalomyelitis (EAE). All mice immunized with peptide 89-101 showed clinical signs. One of six mice immunized with peptide 91-103 showed clinical signs, and 9 of 16 mice, all males, responded with EAE when immunized with peptide 38-88. No clinical EAE was observed in mice immunized with peptide 43-67, 68-88, 55-74, 1-37 or 1-20. A peptide 89-101-specific T cell line was established. At the initial stimulation the line was 29% V beta 8+ versus 21% in normal controls, and the line did not transfer EAE adoptively. After five in vitro stimulations, the percentage of V beta 8+ T cells had increased to 54%, and the line was encephalitogenic. Encephalitogenicity was partially blocked by anti-V beta 8 monoclonal antibody. Thus, over-representation of V beta 8+ TCR by encephalitogenic peptide-specific T cells is not limited to peptide 1-11-specific T cells from H-2u mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental allergic encephalomyelitis in susceptible and resistant strains of mice after adoptive transfer of T cells activated by antibodies to the T cell receptor complex

Lymphoid cells from normal and myelin basic protein (MBP)-immune PL/J, SJL/J and (SJL x PL)F1 hybrid mice were activated by in vitro culture with monoclonal antibodies specific for CD3 or specific T cell receptor (TCR) V beta chains. Lymphoid cells activated in this manner from MBP-immune animals did not readily transfer experimental acute encephalomyelitis (EAE) to naive syngeneic recipients in contrast to lymphoid cells from the same source cultured with concanavalin A (ConA) or myelin basic protein (MBP). However, recipients of anti-TCR antibody-activated MBP-specific blasts showed accelerated onset and increased severity of EAE following immunization with MBP as compared to unmanipulated control animals. Anti-TCR activated cells incorporated [3H]-thymidine at a level comparable to ConA or antigen-stimulated cells and secreted interleukin (IL)-2 at comparable levels Anti-TCR activated blasts were greater than 90% positive for CD3 and alpha/beta TCR, 60% CD4+ and 30% CD8+. PL/J or (SJL x PL)F1 recipients of anti-TCR-activated spleen cells from syngeneic normal mice also had more severe EAE than control mice following immunization with MBP. Non-responder C57BL/10SnJ mice could be converted to responders by infusion of anti-CD3 or anti-V beta 8 monoclonal antibody-treated syngeneic spleen cells taken from normal syngeneic unimmunized mice.

Effects of monoclonal antibody anti-EGF receptor on human nasopharyngeal carcinoma cell and other tumor cells

Three anti-EGF receptor MoAbs were used in these studies. Administration of MoAbs 3 and 176 inhibited tumor formation in nude mice by CNE-2, a poorly differentiated nasopharyngeal carcinoma cell line and A431, an epidermoid carcinoma cell line. When the same MoAbs were used in treatment against HeLa, a cervical carcinoma, tumor growth was not affected. The number of EGF receptors and apparent dissociation constants for 125I-EGF on CNE-2 and A431 was 1.3 x 10(5)/cell (Kd 7.7 x 10(-8) mol/L) and 1.4 x 10(6)/cell (Kd 2.4 x 10(-9) mol/L), respectively. Both MoAbs 3 and 176, capable of competing with EGF for receptor binding, showed significant tumor growth inhibition. MoAb 101 was incapable of blocking the binding of EGF to its receptor, and not as effective as MoAbs 3 and 176 in tumor growth inhibition. Our observation is that the MoAb anti-EGF receptor is cytostatic rather than cytocidal, in vitro against CNE-2 and A431.