[The cases of tracing the source of patients infected with Omicron variant of SARS-CoV-2 based on wastewater-based epidemiology in Shenzhen]

Wastewater-based epidemiology (WBE) is an emerging discipline, which has been applied to drug abuse tracking and infectious disease pathogen surveillance. During the COVID-19 epidemic, WBE has been applied to monitor the epidemic trend and SARS-CoV-2 variants etc. In order to detect hidden COVID-19 cases and prevent transmission in the community, wastewater surveillance system for monitoring SARS-CoV-2 RNA was developed in Shenzhen. The sewage sampling sites were set up in key places such as the port areas, urban villages and residential communities of Futian, Nanshan, Luohu and Yantian districts. From July 26 to November 30, 2022, a total of 369 sewage sampling sites were set up, covering 1.93 million people. Continuous sampling was carried out for 3 hours in the peak period of water use every day. Sewage virus enrichment and SARS-CoV-2 nucleic acid detection were carried out by polyethylene glycol precipitation method and RT-qPCR, and a positive water sample disposal process was molded. This article aims to introduce the case of source tracing of COVID-19 infected patients based on urban sewage in Shenzhen. The sewage monitoring of Honghu water treatment plant in Luohu District played an early warning role, and the source of infection was traced. In the disposal of positive water samples in Futian South Road, Futian District, the important experience of monitoring point layout was obtained. In the sewage monitoring of Nanshan village, Nanshan District, the existence of occult infection was revealed. Sharing the experience of tracing the source of COVID-19 patients to avoid the spread of COVID-19 in the community based on wastewater surveillance of SARS-CoV-2 RNA in Shenzhen, and summarizing the advantages and application prospects of sewage surveillance can provide new ideas for monitoring emerging or re-emerging pathogens that are known to exhibit gastrointestinal excretion in the future.

Serum 25-hydroxyvitamin D levels and peripheral neuropathy in patients with type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Vitamin D is a multifunctional pro-hormone and has widespread actions in human body. Several studies showed a possible association between vitamin D deficiency and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes, but no definite conclusion was available.

METHODS

A systematic review and meta-analysis was performed to comprehensively assess the association between serum 25-hydroxyvitamin D [25(OH)D] levels and DPN in patients with type 2 diabetes. Data from eligible studies were pooled using meta-analysis.

RESULTS

Six studies that involved a total of 1,484 type 2 diabetic patients were finally included into the meta-analysis. Meta-analysis showed that there were obviously decreased serum 25(OH)D levels in DPN patients [weighted mean difference (WMD) = -6.36 ng/ml, 95 % confidence interval (95 % CI) -8.57 to -4.14, P < 0.00001]. Vitamin D deficiency was also significantly associated with increased risk of DPN in patients with type 2 diabetes [odds ratio (OR) 2.88, 95 % CI 1.84-4.50, P < 0.00001]. Meta-analysis of three studies with adjusted estimates showed that vitamin D deficiency was independently associated with increased risk of DPN in patients with type 2 diabetes (OR 2.68, 95 % CI 1.67-4.30, P < 0.0001). Sensitivity analysis showed that there was no obvious change in the pooled estimates.

CONCLUSION

Vitamin D is involved in the development of DPN in type 2 diabetic patients, and vitamin D deficiency is very likely to be associated with DPN in type 2 diabetic patients. Further studies are needed to validate the association between vitamin D deficiency and DPN.

Screening of PAX8 mutations in Chinese patients with congenital hypothyroidism

BACKGROUND

Congenital hypothyroidism (CH) is a neonatal endocrine disease with an incidence of 1:2000 to 1:4000 worldwide. In about 85% of patients CH is secondary to thyroid dysgenesis, but its pathogenesis remains unclear. Thyroid transcription factors, such as paired box transcription factor 8 (PAX8), play an important role in thyroid organogenesis and development.

AIM

To screen PAX8 mutations in Chinese CH patients and characterize the features of PAX8 mutations in China.

MATERIALS AND METHODS

Blood samples were collected from 300 CH patients in Shandong Province, China, and genomic DNA was extracted from peripheral blood leukocytes. Using PCR and direct sequencing, exon 3 and exon 4 of PAX8 were analyzed.

RESULTS

Analysis of PAX8 in 300 CH patients revealed heterozygous missense mutations or variations in two unrelated patients; one was a known missense mutation G92A, resulting in an arginine to histidine substitution at codon 31, the other was a missense variation G122T, resulting in the substitution of a glycine at position 41 by a valine residue. The patient with the R31H mutation had CH with thyroid hypoplasia, while the patient with the G41V variation had CH with a eutopic and normal-sized thyroid gland.

CONCLUSION

We report a heterozygous missense mutation and a variation in PAX8 in two out of 300 unrelated Chinese CH patients, showing that the PAX8 mutation rate is very low in CH patients in China.

A genome-wide scan for coronary heart disease suggests in Indo-Mauritians a susceptibility locus on chromosome 16p13 and replicates linkage with the metabolic syndrome on 3q27

Prevalence of coronary heart disease (CHD), of type 2 diabetes (T2DM) and of the metabolic syndrome are in Mauritius amongst the highest in the world. As T2DM and CHD are closely associated and have both a polygenic basis, we conducted a 10 cM genome scan with 403 microsatellite markers in 99 independent families of North-Eastern Indian origin including 535 individuals. Families were ascertained through a proband with CHD before 52 years of age and additional sibs with myocardial infarction (MI) or T2DM. Model-free two-point and multipoint linkage analysis were performed using the Mapmarker-Sibs (MLS) and maximum-likelihood-binomial (MLB) programs for autosomal markers and the Aspex program for chromosome X markers. In a second step, additional markers were studied to increase the genetic map density in three regions on chromosomes 3, 8 and 16 where initial indication for linkage was found. Our data show suggestive linkage with CHD on chromosome 16p13-pter with the MLS statistics at 8.69 cM (LOD = 3.06, P = 0.00017) which partially overlaps with a high pressure (HBP) peak. At the same locus, a nominal indication for linkage with T2DM was found in 35 large T2DM Pondicherian families also having Indian origin. With respect to region 8q23, we found suggestive linkage with T2DM (LOD = 2.55, P = 0.00058) as well as with HBP. On 3q27, we replicated previous indication for linkage found in Caucasians (for the metabolic syndrome and for diabetes) according to the categorized trait for CHD and MI with the MLB statistics (LOD = 2.13, P = 0.0009). The genome scan also revealed nominal evidence of linkage with CHD on 10q23 (LOD = 2.06, P = 0.00188). Interestingly, we detected in the same region overlapping linkages with three QTLs: age of onset of CHD (LOD = 2.03), HDL cholesterol (LOD = 1.48) and LDL/HDL ratio (LOD = 1.34). Ordered-subset analysis based on family body mass index ranking replicated finding on 2q37 for T2DM (at Calpain 10 locus). These results show the first evidence for susceptibility loci that predispose to CHD, T2DM and HBP in the context of the metabolic syndrome.

Isolation and characterization of phytochelatin synthase in rice seedlings

Rice plants were treated with 50 microM copper sulfate to induce the synthesis of phytochelatins by means of a series of enzymatic reactions, including that of photochelatin synthase. Phytochelatin synthase extracted from 3-week-old rice seedlings was purified through a series of steps including precipitation with ice-chilled acetone, QAE A-50 anion exchange column, Amicon XM-50 ultrafiltration and Polybuffer Exchange (PBE) 94 chromato-focusing. This enzyme had a molecular mass of about 100 kDa with an isoelectric point of 4.0. The temperature and pH optima of this enzyme were 55 degrees C and pH 7.5, respectively. The enzyme was thermal tolerable and unstable under refrigeration at 4 or -20 degrees C. Cadmium was the most effective stimulator, followed by lead, copper, silver, cobalt and other divalent cations. Calcium and magnesium had no effect.

Three major G6PD-deficient polymorphic variants identified among the Mauritian population

We report the results of the first epidemiological study investigating glucose 6-phosphate dehydrogenase (G6PD) deficiency among the heterogenous Mauritian population. Mauritius has a population of approximately 1 million, and of these 66.8% are Indo-Mauritian (of Indian origin), 27.9% are Creoles (of African ancestry) and 2.1% are Sino-Mauritian, predominantly of Chinese origin. Of the 1435 Mauritian males tested, 73 (5.1%) were G6PD deficient. However, the prevalence varied considerably between the two major ethnic groups: 35/1157 (3.0%) for Indo-Mauritians and 37/267 (13.9%) for Creoles. Molecular analysis revealed three major deficient polymorphic variants; G6PD Orissa, G6PD Mediterranean and G6PD A-. G6PD Orissa (nt 131 G-->C; residue 44 Ala-->Gly) was found to be the most common variant among Indo-Mauritians: this deficient variant was recently identified to be highly characteristic of the tribal groups in central India. In Creoles the most common deficient variant was G6PD A- (27/37). These data are consistent with the different ancestral contributions to the present gene pool of the Mauritian population. This study has provided further information as to the precise nature of G6PD deficiency at the molecular level among Indians, about whom previously there was scant information. The data presented suggest that G6PD Orissa is widespread in central and southern states of India. Additionally, the identification and frequency of G6PD-deficient alleles in Mauritius is of public-health importance.

Separation of urea, uric acid, creatine, and creatinine by micellar electrokinetic capillary chromatography with sodium cholate

The capillary electrophoretic separation of the four nonprotein nitrogenous compounds (NPNs; urea, uric acid, creatine, and creatinine) typically employed in clinical and medical settings for the monitoring of renal function is described. Successful resolution of these compounds is achieved with the use of a bile salt micelle system composed of sodium cholate at phosphate buffer pH 7.4. The elution patterns of four NPNs are obtained within 30 min with a voltage of 30 kV. The effect of varying the applied voltage, temperature, and the mole ratio of phosphate buffer with bile salt surfactant on the migration behavior is also examined.

Inactivation and conformational changes of aminoacyclase in trifluoroethanol solutions

The inactivation and unfolding of aminoacyclase (EC 3.5.1.14) during denaturation by different concentrations of trifluoroethanol (TFE) have been studied. A marked decrease in enzyme activity was observed at low TFE concentrations. The kinetic theory of the substrate reaction during irreversible inhibition of enzyme activity described previously by Tsou [Tsou (1988), Adv. Enzymol. Related Areas Mol. Biol. 61, 381-436] was applied to study the kinetics of the inactivation course of aminoacyclase during denaturation by TFE. The inactivation rate constants for the free enzyme and substrate-enzyme complex were determined by Tsou's method. The inactivation reaction was a monophasic first-order reaction. The kinetics of the unfolding course were a biphasic process consisting of two first-order reactions. At 2% TFE concentration, the inactivation rate of the enzyme was much faster than the unfolding rate. At a higher concentration of TFE (10%), the inactivation rate was too fast to be determined by conventional methods, whereas the unfolding course remained as a biphasic process with fast and slow reactions occurring at measurable rates. The results suggest that the aminoacyclase active site containing Zn2+ ions is situated in a limited and flexible region of the enzyme molecule that is more fragile to the denaturant than the protein as a whole.

Immunoglobulin class and subclass distribution of eye muscle and fibroblast antibodies in patients with thyroid-associated ophthalmopathy

OBJECTIVE

The investigation of the antibody response in thyroid-associated ophthalmopathy (TAO) using different antigens and assays has given inconsistent results. We have analysed antibodies against eye muscle and control antigens in a large group of TAO patients to assess whether specific eye muscle antibodies exist in TAO. We have also evaluated the presence of IgA and IgM class antibodies and examined IgG subclass distribution.

DESIGN

Sera were obtained from all patients (TAO, Graves' disease without ophthalmopathy and Hashimoto's thyroiditis) within one year of diagnosis. Sera were also collected from healthy controls, with no family history of autoimmune thyroid disease.

PATIENTS

Thirty-eight patients had Graves' disease with Grade III or greater TAO; 15 patients had Graves' disease without ophthalmopathy and nine had Hashimoto's thyroiditis without any eye signs. The control group consisted of 14 subjects.

MEASUREMENTS

Antibodies against porcine eye and skeletal muscle, human eye (membrane and soluble antigen) and skeletal muscle, human thyroid microsomal and thyroglobulin antigens and dermal and orbital fibroblast antigens were assessed using ELISA. Antibody isotypes and IgG subclasses were studied for porcine and human eye muscle antibodies. Eye muscle (porcine and human) and orbital fibroblast antibodies were further analysed by immunoblotting.

RESULTS

There were no significant differences in the ability of either IgG or IgA in sera from the different groups to bind porcine and human eye muscle antigens. There was a significant correlation (P < 0.0001) between the binding to porcine eye muscle and skeletal muscle antigens (for both IgG and IgA). There was no difference between sera from TAO patients and control subjects in their binding to eye muscle fibroblasts for both IgG and IgA antibodies. However, IgA antibody activity against dermal fibroblasts differed significantly between TAO patients and controls (P < 0.05). By immunoblotting, the frequency of IgA antibodies recognizing 21 kDa (40% of patients) and 62 kDa (52%) bands in porcine eye muscle blots and 20, 24 and 38 kDa bands in blots of human eye muscle (soluble) antigen differed significantly between patients with TAO and controls (P < 0.05 in all cases). IgG antibodies recognizing 80 and 92 kDa bands in blots of the subcellular membrane antigen prepared from orbital fibroblasts were found more frequently in patients with TAO compared with controls (P < 0.05 in both cases).

CONCLUSIONS

We found no evidence that eye muscle membrane or fibroblast antibodies are present in a significant proportion of TAO patients, using ELISAs based on antigens prepared from several sources. We have also failed to demonstrate the presence of previously described specific, TAO-associated antibodies, including those directed against a 64 kDa protein in eye muscle and a 23 kDa protein in fibroblasts. IgA class antibodies reactive with orbital components appeared to be more strongly associated with TAO than those of the IgG class, though even this relationship is weak. These results suggest that antibodies are of secondary importance in the pathogenesis of TAO, which is most likely a T cell-mediated disorder.

Expression and function of multiple regulators of complement activation in autoimmune thyroid disease

Membrane attack complexes of complement occur around thyroid follicles in Graves' disease and Hashimoto's thyroiditis. The lytic potential of such complexes is controlled by membrane-bound and fluid phase regulators and we have investigated the role of these in autoimmune thyroid disease. By immunohistochemical staining, clusterin and S-protein were found in all nine thyroid specimens from patients with Graves' disease and S-protein was found in one of two Hashimoto glands. CD46, CD55 and CD59 were found on thyroid cells in all specimens. CD46 and CD55 expression occurred on thyroid cells cultured in vitro and was increased significantly by culture with interleukin-1 (IL-1) and interferon-gamma (IFN-gamma), which are known to be released by the lymphocytic infiltrate in these conditions. Blocking CD55 had a weak and inconsistent effect on complement-mediated thyroid cell killing in vitro but, in four of five experiments, blocking CD46 enhanced killing. However, the effect of blocking CD59 was greater in all cases than blocking CD46 or CD55. Expression of these fluid phase and membrane-bound proteins may be important in determining the severity of thyroid damage produced by complement fixation in Graves' disease and Hashimoto's thyroiditis.

Profound deficiency in normal circulating T cells in erythrodermic cutaneous T-cell lymphoma

BACKGROUND AND DESIGN

To accurately assess tumor burden in cutaneous T-cell lymphoma as well as to determine the number of residual normal circulating T cells, it is necessary to accurately distinguish malignant cells. Because cutaneous T-cell lymphoma cells regularly display many normal phenotypic markers of T cells (CD2+, CD3+, CD4+) these surface proteins have been of limited value. We have used a set of monoclonal antibodies with specificity for those T-cell receptor proteins containing variable regions on the beta chain to distinguish normal from malignant T cells in patients with cutaneous T-cell lymphoma.

RESULTS

The results revealed an unanticipated and profound expansion of the malignant cell populations (59% to 87% of blood T cells) in six patients with total T-cell counts in the normal or near normal range. By subtracting the percentages of malignant T cells, identified in this manner, from the total T-cell counts, we found that the residual normal T-cell compartments were small (0 to 0.155 x 10(9)/L) in four of the six patients. Sézary cell counts by peripheral blood smear analysis by routine light microscopy underestimated the number of malignant T cells. Markedly elevated CD4/CD8 ratios (10 to 90) occurred in all cases, reflecting expansion of the CD4+ malignant population and parallel reduction of the normal residual CD8+ subset.

CONCLUSIONS

Patients with erythrodermic cutaneous T-cell lymphoma often have markedly depressed levels of normal blood T cells, to the range seen in advanced acquired immunodeficiency syndrome, and absolute numbers of malignant cells substantially exceed those recognized with less sensitive techniques.

Skin-selective lymphocyte homing mechanisms in the pathogenesis of leukemic cutaneous T-cell lymphoma

The concept of skin-associated lymphoid tissue embraces those cells and functions that are integrated in the cutaneous host defense. Recently, it has been possible to identify those circulating T-cells that are skin associated. These cells display the cell-surface phenotype of memory T cells (CD45RO+) and express the cutaneous lymphocyte antigen, a tissue-selective homing receptor involved in directing T-cell traffic to inflamed skin. To investigate the participation of this skin-associated T-cell subset in the pathogenesis of cutaneous T-cell lymphoma, we studied 16 patients with erythrodermic cutaneous T-cell lymphoma for the presence of these surface proteins on circulating cells. Results were compared with eight patients in remission and eight with minimal patch-plaque cutaneous T-cell lymphoma. The mean expression of both CD45RO and cutaneous lymphocyte antigen were significantly greater in the erythrodermic patients than in the other two patient groups. Expression of these markers was shown to be on the cells of the malignant clone by two-color flow cytometry. These results demonstrate that the malignant cells of cutaneous T-cell lymphoma express the markers of skin homing lymphocytes and that their levels are increased in the erythrodermic cutaneous T-cell lymphoma patients. Moreover, the findings suggest a critical role for the skin-selective homing receptor cutaneous lymphocyte antigen in the pathogenesis of cutaneous T-cell lymphoma.

Stimulation of cutaneous T-cell lymphoma cells with superantigenic staphylococcal toxins

Stimulation of T cells by superantigenic bacterial toxins is selective for cells bearing particular B chain variable (VB) gene segments of T-cell receptor (TCR). In humans, staphylococcal exfoliating toxin (ExT) and toxic shock syndrome toxin-1 (TSST-1) are known to stimulate VB 2-bearing T cells and staphylococcal enterotoxin B (SEB) does not activate VB 2-bearing T cells. We examined the proliferative response of cutaneous T-cell lymphoma (CTCL) cells to ExT, TSST-1, and SEB. Leukemic VB 2.1-bearing CTCL cells were reactive to ExT and TSST-1, but not SEB. In addition, two leukemia CTCL-VB 2- cell samples (one of which was VB 8) showed no substantial response to ExT. Thus, it was shown that Sezary cells proliferate in response to bacterial superantigens in a manner that is restricted by their VB usage. The addition of interleukin-1 (IL-1) in combination with ExT enhanced the stimulative response of VB 2.1-bearing CTCL cells that were pre-cultured with ExT for 7 d, suggesting that IL-1 can be a co-factor for the stimulation. The present study indicates that the superantigen reaction occurs with CTCL cells and implies a possible involvement of bacterial toxins in the pathogenesis of CTCL.

Biological activity in the repopulating rat spermatocyte after the withdrawal of gossypol treatment: I. The activity for DNA synthesis

Mature male rats were treated with gossypol for various lengths of time after which the treatment was stopped to allow the arrested spermatogonia to revive. Fifteen days after withdrawal of the drug treatment, the arrested spermatogonia entered into the meiotic division and then reached the pachytene stage. The meiotic cells derived from the arrested spermatogonia were the first generation of the differentiated germ cells after long-term gossypol treatment. Centrifugal elutriation technique was used to isolate the repopulating pachytene spermatocytes (RPS) or the control pachytene spermatocytes (CPS) from the rat testis with or without receiving gossypol pretreatment. In vitro culture condition for RPS and CPS was established for the synthesis of DNA by the measurement of 3H-thymidine incorporation. The activity for DNA synthesis in RPS was studied and compared to that of the CPS. It was concluded that after gossypol treatment for various times, the incorporation of 3H-thymidine into the cellular thymidine pool of RPS was not affected. However, the activity for DNA synthesis in RPS was significantly lower than that in the CPS. The synthetic activity for DNA was reduced by 14%, 26%, 42%, 40%, and 40% in the RPS for the gossypol pretreatment of 3, 4, 6, 7, and 8 weeks, respectively.

External structures of all larval instars of five common Culex species in Taiwan

The external structures of all larval instars of 5 different species of Culex were studied for the first time in Taiwan. Pictorial keys are provided for use to distinguish each species at any instar; one key is to larval instars of 5 common Culex species in Taiwan and the second, key to species of 5 common Culex species in Taiwan.

Malic dehydrogenase patterns in different strains of Schistosoma japonicum and subspecies of Oncomelania hupensis

Malic dehydrogenase (MDH) of the Formosan Philippine and Indonesian Strains of Schistosoma japonicum and 3 subspecies of snails, Oncomelania hupensis formosana, O. h. quadrasi, and O. h. lindoensis were identified by disc electrophoresis with 10.5% acrylamide gel columns using tris-malic buffer. Male worm extracts of S. japonicum demonstrated 3, 2, and 2 clear MDH patterns and female worm extracts showed patterns of 2, 1 and 1 for the Formosan, Philippine and Indonesian strains of the parasite, respectively. MDH patterns were the same for all 3 subspecies of snails; one major and one minor band being found in all.