Norepinephrine and amino acids in prepyriform cortex of rats fed imbalanced amino acid diets

Monoamines and amino acids were measured in anterior prepyriform cortex (PPC) and anterior cingulate cortex (CC) of male Sprague-Dawley rats after they were offered basal, imbalanced (IMB) or corrected amino acid diets, limited in threonine (THR) or isoleucine (ILE). In the THR study, brains were taken after 2.5 hr of feeding, when intake of THR-IMB was just depressed. In the ILE study the brains were taken after 3.5 hr on ILE-IMB, a less severely imbalanced ration, before the onset of food intake depression. The PPC has been shown to be involved in the acute response of animals to imbalanced amino acid diets. In the PPC from the IMB diet groups, NE was reduced by 30%, but the other monoamines were unchanged. In CC, an area involved in the adaptive, but not the acute feeding response to imbalanced diets, the monoamines were unchanged in the IMB diet groups. In both studies, in both tissues, the limiting amino acids were decreased in the IMB groups, although the decrease of ILE in the CC failed to reach significance. The remaining indispensable amino acids, added to create the imbalance, were slightly reduced in the THR-IMB group, but not in the ILE-IMB group in both tissues. Thus, the amino acid patterns were altered in the PPC and CC, as they are in whole brains from animals fed imbalanced amino acid diets. These results also suggest that the concentration of NE in the PPC may be associated with the initial food intake response of animals to imbalanced amino acid diets.     

Estimation of the genetic contribution of presenilin-1 and -2 mutations in a population-based study of presenile Alzheimer disease

Two closely related genes, the presenilins ( PS ), located at chromosomes 14q24.3 and 1q42.1, have been identified for autosomal dominant Alzheimer disease (AD) with onset age below 65 years (presenile AD). We performed a systematic mutation analysis of all coding and 5'-non-coding exons of PS -1 and PS -2 in a population-based epidemiological series of 101 unrelated familial and sporadic presenile AD cases. The familial cases included 10 patients of autosomal dominant AD families sampled for linkage analysis studies. In all patients mutations in the amyloid precursor protein gene ( APP ) had previously been excluded. Four different PS -1 missense mutations were identified in six familial cases, two of which where autosomal dominant cases. Three mutations resulted in onset ages above 55 years, with one segregating in an autosomal dominant family with mean onset age 64 years (range 50-78 years). One PS -2 mutation was identified in a sporadic case with onset age 62 years. Our mutation data provided estimates for PS -1 and PS -2 mutation frequencies in presenile AD of 6 and 1% respectively. When family history was accounted for mutation frequencies for PS -1 were 9% in familial cases and 18% in autosomal dominant cases. Further, polymorphisms were detected in the promoter and the 5'-non-coding region of PS -1 and in intronic and exonic sequences of PS -2 that will be useful in genetic association studies.      

Inhibition of the development of immediate hypersensitivity by staphylococcal enterotoxin B

We investigated the ability of staphylococcal enterotoxin B (SEB) to modify the immediate hypersensitivity response induced in BALB/c mice following sensitization to ovalbumin (OVA), a response mediated by OVA-reactive Vβ8 T cells. Mice were sensitized by skin painting with OVA every second day over a period of 2 weeks. SEB, a potent activator of Vβ8⁺ T cells, was administered at the same site where OVA was applied (skin of the lower abdomen) following two different protocols. In protocol (A) SEB was injected intradermally 1 day before painting with OVA and on day 7; in protocol B, SEB was injected each time OVA was applied to the skin (eight times). SEB (but not SEA) altered the development of immediate hypersensitivity to OVA, as demonstrated by the reduction in allergen-specific IgE, decreased OVA-specific immediate skin test responsiveness, and prevented the development of increased airways responsiveness after bronchial challenge with OVA. Injections of SEB did not alter the proliferative responses of local draining lymph node cells or spleen mononuclear cells to OVA, indicating that administration of SEB did not inhibit the sensitization to OVA, but shifted the immune response away from an immediate type response (IgE/IgG₁) to IgG_2a, IgG_2b and IgG₃. Although both protocols of SEB treatment did not lead to a major deletion of the Vβ8 T cell population, they did reduce the proliferative response of Vβ8⁺ T cells to OVA. These data indicate that the bacterial toxin SEB is capable of modifying the immediate hypersensitivity response induced by OVA by altering the functional capacity of antigen-reactive Vβ8 T cells.     

The pH dependent amelogenin solubility and its biological significance

Amelogenins are a group of extracellular enamel matrix proteins which are believed to be involved in the regulation of the size and habit of enamel crystals. The aim of this study was to compare the solubility properties of several amelogenins in various pH (4.0-9.0) solutions with an ionic strength (IS) of 0.15 M using the Micro BCA protein assay at 25 degrees C or 37 degrees C. The solubility of the recombinant amelogenin rM179 was lowest (0.7 mg/ml) close to its isoelectric point and it increased below and above this point. The solubility of the recombinant amelogenin rM166 remained almost the same (1-2 mg/ml) as the pH rose from 6.0 to 9.0 and it increased as the solution became more acidic. Synthetic "tyrosine-rich amelogenin polypeptide" (TRAP) was extremely insoluble (<0.2 mg/ml) in the pH range studied while synthetic "leucine-rich amelogenin polypeptide" (LRAP) was readily soluble (>3.3 mg/ml). The native porcine amelogenin with apparent molecular weight 25 kDa shared similar solubility behavior to rM179. The porcine 23 kDa amelogenin was only sparingly soluble (0.3-0.8 mg/ml) over a wide range of pH. Interestingly, the porcine 20 kDa amelogenin was remarkably soluble in the pH range of 4.0 to 6.0 (approximately 12 mg/ml), but the solubility dropped strikingly to only approximately 0.2 mg/ml at pH larger than approximately 7.0. The strong dependence of amelogenin solubility on solution pH may be involved in the regulation of aggregation, enzymatic degradation and the binding properties of amelogenins, thus playing an important role in enamel biomineralization.     

Comparison of ethanol versus formalin fixation on preservation of histology and RNA in laser capture microdissected brain tissues

Although RNA can be retrieved from formalin-fixed, paraffin-embedded (FFPE) tissues, the yield is low, and the RNA is fragmented. Recent advances in gene expression profiling underscore the importance of identifying a fixative that preserves histology and mRNA. We demonstrated that, for immersion fixation of brains, 70% ethanol is superior to formalin for mRNA preservation. RNA yield from ethanol-fixed tissues was 70% of the yield from fresh frozen specimens, but only a negligible quantity was recovered from formalin-fixed tissues. RNA from ethanol-fixed brains showed integrity comparable to RNA from fresh frozen tissues, and RT-PCR using RNA from ethanol-fixed tissues was consistently successful. RNA from FFPE tissues composed of low-molecular weight fragments, and their use in RT-PCR failed repeatedly. The yield and quality of RNA from ethanol-fixed brains were unaffected after immersion at 4 degrees C for 2 weeks. In a blinded comparison to FFPE tissues, ethanol-fixed specimens were judged to show comparable histology and superior immunostaining. After laser capture microdissection (LCM), we failed to recover mRNA from FFPE tissues but retrieved mRNA from ethanol-fixed tissues for RT-PCR and cDNA microarray analysis. We conclude that 70% ethanol preserves RNA integrity and is suitable for expression profiling of brain tissues by LCM and cDNA microarray.     

Effects of a Rice Bran Dietary Intervention on the Composition of the Intestinal Microbiota of Adults with a High Risk of Colorectal Cancer: A Pilot Randomised-Controlled Trial

Rice bran exhibits chemopreventive properties that may help to prevent colorectal cancer (CRC), and a short-term rice bran dietary intervention may promote intestinal health via modification of the intestinal microbiota. We conducted a pilot, double-blind, randomised placebo-controlled trial to assess the feasibility of implementing a long-term (24-week) rice bran dietary intervention in Chinese subjects with a high risk of CRC, and to examine its effects on the composition of their intestinal microbiota. Forty subjects were randomised into the intervention group (n = 19) or the control group (n = 20). The intervention participants consumed 30 g of rice bran over 24-h intervals for 24 weeks, whilst the control participants consumed 30 g of rice powder on the same schedule. High rates of retention (97.5%) and compliance (≥91.3%) were observed. No adverse effects were reported. The intervention significantly enhanced the intestinal abundance of Firmicutes and Lactobacillus, and tended to increase the Firmicutes/Bacteroidetes ratio and the intestinal abundance of Prevotella_9 and the health-promoting Lactobacillales and Bifidobacteria, but had no effect on bacterial diversity. Overall, a 24-week rice bran dietary intervention was feasible, and may increase intestinal health by inducing health-promoting modification of the intestinal microbiota. Further larger-scale studies involving a longer intervention duration and multiple follow-up outcome assessments are recommended.     

Territorywide Study of Early Coronavirus Disease Outbreak,Hong Kong,China

Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10⁻³ substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.     

Rising Ethnic Inequalities in Acute Rheumatic Fever and Rheumatic Heart Disease,New Zealand, 2000–2018

We describe trends in acute rheumatic fever (ARF), rheumatic heart disease (RHD), and RHD deaths among population groups in New Zealand. We analyzed initial primary ARF and RHD hospitalizations during 2000–2018 and RHD mortality rates during 2000–2016. We found elevated rates of initial ARF hospitalizations for persons of Māori (adjusted rate ratio [aRR] 11.8, 95% CI 10.0–14.0) and Pacific Islander (aRR 23.6, 95% CI 19.9–27.9) ethnicity compared with persons of European/other ethnicity. We also noted higher rates of initial RHD hospitalization for Māori (aRR 3.2, 95% CI 2.9–3.5) and Pacific Islander (aRR 4.6, 95% CI 4.2–5.1) groups and RHD deaths among these groups (Māori aRR 12.3, 95% CI 10.3–14.6, and Pacific Islanders aRR 11.2, 95% CI 9.1–13.8). Rates also were higher in socioeconomically disadvantaged neighborhoods. To curb high rates of ARF and RHD, New Zealand must address increasing social and ethnic inequalities.     

The use of natural interferon alpha conjugated to a monoclonal antibody anti mammary epithelial mucin (Mc5) for the treatment of human breast cancer xenografts

Summary An immunoconjugate composed of natural interferon (nIFN) bound in a noncleavable fashion to a monoclonal antibody (MoAb) recognizing a breast epithelial membrane mucin (Mc5) was used to treat xenografts of a human mammary carcinoma cell line (MCF-7) growing in nude mice. The immunoconjugate (nIFN/Mc5) was administered as 20 intralesional (i.l.) injections to 1 of 2 xenografts in each animal. It was found that nIFN/Mc5 produced a significant enhancement of the growth inhibitory actions of nIFN on the injected tumors. Further enhancement was obtained when nIFN or nIFN together with Mc5 (at a dose 10 times larger than that present in nIFN/Mc5) were added to the immunoconjugate. Biodistribution experiments showed that the uptake of¹²⁵I-nIFN/Mc5 by the tumors was greater and its elimination slower than for¹²⁵I-nIFN alone or conjugated to irrelevant mouse IgG₁. In addition, the immunoconjugate up-regulated the antigenic expression of a breast epithelial membrane mucin by the carcinoma cells, an up-regulation which was not significantly different from that produced by nIFN alone. The contralateral noninjected tumors exposed to systemic levels of the immunoconjugate showed an enhancement of antitumor effects, but to a lesser extent than the injected tumors. These findings suggest that the enhancement of the growth inhibitory action of the immunoconjugate was related to the specific binding of Mc5 which targeted the IFN to the carcinoma cells and impeded its elimination. It is likely that the targeting was favored by the IFN-mediated up-regulation of antigenic expression by the carcinoma cells, thereby producing a cascade of interrelated effects. The results of this study point out the feasibility and potential usefulness of IFN treatment by means of immunoconjugates as well as the worth of pursuing and improving this form of therapy.