[Characteristics of genotype of monogenic nephrolithiasis in Chinese pediatric patients with nephrolithiasis]

Objective: To analyze the genotype characteristics of children with monogenic nephrolithiasis. Methods: The clinical data and genetic test results of 56 children with monogenic nephrolithiasis diagnosed and treated in Beijing Friendship Hospital, Capital Medical University from January 2016 to December 2020 were analyzed retrospectively. All pediatric patients were diagnosed by whole exome sequencing, and the genotype characteristics of the children were analyzed. Results: Among 56 children with monogenic nephrolithiasis, there were 39 males and 17 females, with an average age of 4 years (range, 5 months to 14 years). A total of 11 genes were found to have mutations, including 7 autosomal recessive genes, 1 X-linked recessive gene, and 3 genes with both recessive and dominant, of which HOGA1 gene mutation was the most common (16 cases, 28.6%), followed by AGXT gene (15 cases, 26.8%), SLC3A1 gene (6 cases, 10.7%), SLC7A9 gene (5 cases, 8.9%) and GRHPR gene (5 cases, 8.9%). The mutation types included nonsense mutations, frameshift mutations and splicing mutations, with 14 novel mutations. Genes such as AGXT, GRHPR and HOGA1 have hotspot mutations or hotspot mutation regions, which are c. 815-816 insGA and c. 33dupC mutation, c.864-865delTG mutation and c. 834-834+1 mutation region; SLC3A1 and SLC7A9 genes had 9 novel mutations, but no hotspot mutation or hotspot regions were found. Conclusion: Monogenic nephrolithiasis is rare and mostly autosomal recessive in Chinese children, with mutations in the causative genes HOGA1, AGXT, SLC3A1,SLC7A9 and GRHPR. AGXT, GRHPR and HOGA1 genes have hotspot mutations or hotspot mutation regions, and mutations may have ethnic differences.

Differences in hypertension and prehypertension among people living with and without HIV in China: role of HIV infection and antiretroviral therapy

OBJECTIVES

Hypertension is a growing health concern in people living with HIV (PLWH). However, association between HIV infection and hypertension is equivocal.

METHODS

In all, 1472 PLWH and 2944 HIV-negative individuals frequency-matched by age and sex were derived from the baseline survey of Comparative HIV and Aging Research in Taizhou (CHART), China. Prehypertension was defined as systolic blood pressure (BP) of 120-139 mmHg and/or diastolic blood pressure of 80-89 mmHg.

RESULTS

Despite the fact that prevalence of hypertension was overall lower among PLWH than among HIV-negative people (21.1% vs. 29.1%, P < 0.001), it was similar at ages 18-29 (7.6% vs. 8.5%) and 30-44 years (17.1% vs. 18.5%) but significantly lower in PLWH at ages 45-59 (26.1% vs. 40.7%) and 60-75 years (37.1% vs. 57.3%). Prehypertension prevalence was consistently higher in PLWH across all age groups. In the model adjusting for traditional risk factors, HIV infection was associated with hypertension (adjusted odds ratio [aOR] = 1.27, 95% confidence interval: 1.04-1.55) and prehypertension (aOR = 1.77, 95% CI: 1.51-2.08), and attenuated after additional adjustment for abdominal obesity. Age-stratified analysis showed that these associations of HIV with hypertension were observed at ages 18-29 and 30-44 years and associations with prehypertension were observed at ages 18-29, 30-44 and 45-59 years only. Years since HIV diagnosis and stavudine use were the HIV-specific factors independently associated with hypertension or/and prehypertension.

CONCLUSIONS

HIV infection is independently associated with prehypertension and hypertension especially at younger ages, and this risk may increase as treatment becomes prolonged. Our findings reinforce the urgent necessity for active BP screening and control strategies be adopted for PLWH in China.

Molecular Epidemiology and Risk Factors of Blastocystis sp. Infections Among General Populations in Yunnan Province, Southwestern China

BACKGROUND

Blastocystis is a common enteric parasite of controversial pathogenic roles in human diseases. Although the prevalence of Blastocystis infections has been investigated in a diverse range of populations, there is little knowledge on the molecular epidemiology and risk factors of Blastocystis infections among general populations in southeastern China.

MATERIALS AND METHODS

A total of 507 individuals were randomly selected in Yunnan province, China from July 2016 to March 2017. Stool specimens were sampled for detection of Blastocystis sp. using PCR assay, and the risk factors of Blastocystis infections were identified. Blastocystis isolates were subtyped, and the associations of Blastocystis infections and subtypes with clinical manifestations were examined.

RESULTS

The overall detection rate of Blastocystis sp. was 9.47% (95% CI: 7.13-12.44%). Toilet type (OR = 3.248, 95% CI: 1.245-8.473), anemia (OR = 2.601, 95% CI: 1.245-8.473) and type of daily drinking water (OR = 3.11, 95% CI: 1.557-6.213) were identified as risk factors of Blastocystis infections; however, Blastocystis infections showed no associations with clinical symptoms. Four subtypes (ST1 to ST4) were characterized in Blastocystis isolates, in which ST3 was predominant (4.73%, 95% CI: 3.2-6.94%), followed by ST1 (3.16%, 95% CI: 1.95-5.07%), ST4 (1.38%, 95% CI: 0.07-2.82%) and ST2 (0.2%, 95% CI: 0-1.11%). In addition, ST1 subtype infection was found to correlate with anemia (OR = 4.66, 95% CI: 1.631-14.314).

CONCLUSIONS

There is a high prevalence of Blastocystis infections among general populations in Yunnan province, southwestern China, and toilet type, anemia and type of daily drinking water are risk factors of Blastocystis infections. ST3 is the dominant subtype of Blastocystis sp. characterized, and ST1 correlates with anemia. Improving hygiene conditions, developing healthy lifestyles and intensifying health education programs are strongly recommended to reduce the prevalence and transmission potential of Blastocystis infections.

An odorant receptor mediates the attractiveness of cis-jasmone to Campoletis chlorideae, the endoparasitoid of Helicoverpa armigera

Parasitic wasps rely on olfaction to locate their hosts in complex chemical environments. Odorant receptors (ORs) function together with well-conserved odorant coreceptors (ORcos) to determine the sensitivity and specificity of olfactory reception. Campoletis chlorideae (Hymenoptera: Ichneunmonidae) is a solitary larval endoparasitoid of the cotton bollworm, Helicoverpa armigera, and some other noctuid species. To understand the molecular basis of C. chlorideae's olfactory reception, we sequenced the transcriptome of adult male and female heads (including antennae) and identified 211 OR transcripts, with 95 being putatively full length. The tissue expression profiles, as assessed by reverse-transcription PCR, showed that seven ORs were expressed only or more highly in female antennae. Their functions were analysed using the Xenopu slaevis oocyte expression system and two-electrode voltage-clamp recordings. CchlOR62 was tuned to cis-jasmone, which was attractive to female C. chlorideae adults and H. armigera larvae in the subsequent behavioural assays. Further bioassays using caged plants showed that the parasitism rate of H. armigera larvae by C. chlorideae on cis-jasmone-treated tobacco plants was higher than on the control plants. Thus, cis-jasmone appears to be an important infochemical involved in the interactions of plants, H. armigera and C. chlorideae, and CchlOR62 mediates the attractiveness of cis-jasmone to C. chlorideae.

Integrated analysis of long noncoding RNA and mRNA expression profiles reveals the potential role of long noncoding RNA in different bovine lactation stages

Long noncoding RNA (lncRNA) play a critical role in mammary development and breast cancer biology. Despite their important role in the mammary gland, little is known of the roles of lncRNA in bovine lactation, particularly regarding the molecular processes underlying it. To characterize the role of lncRNA in bovine lactation, 4 samples of Holstein cow mammary gland tissue at peak and late lactation stages were examined after biopsy. We then profiled the transcriptome of the mammary gland using RNA sequencing technology. Further, functional lncRNA-mRNA coexpression pairs were constructed to infer the function of lncRNA using a generalized linear model, followed by gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. More than 1,000 putative lncRNA were identified, 117 of which were differentially expressed between peak and late lactation stages. Bovine lncRNA were shorter, with fewer exon numbers, and expressed at significantly lower levels than protein-coding genes. Seventy-two differentially expressed (DE) lncRNA were coexpressed with 340 different protein-coding genes. The KEGG pathway analysis showed that target mRNA for DE lncRNA were mainly related to lipid and glucose metabolism, including the peroxisome proliferator-activated receptors and 5' adenosine monophosphate-activated protein kinase signaling pathways. Further bioinformatics and integrative analyses revealed that 12 DE lncRNA potentially played important roles in bovine lactation. Our findings provide a valuable resource for future bovine transcriptome studies, facilitate the understanding of bovine lactation biology, and offer functional information for cattle lactation.

Effects of Talaromyces marneffei infection on mortality of HIV/AIDS patients in southern China: a retrospective cohort study

OBJECTIVE

Talaromyces marneffei is an opportunistic infection with high morbidity among human immunodeficiency virus (HIV)/AIDS patients in Southeast Asia and southern China. Its effects on mortality in HIV/AIDS patients has not been clearly elucidated.

METHODS

We conducted a retrospective cohort study of hospitalized HIV-infected individuals at the Fourth People's Hospital of Nanning, Guangxi, China during 2012-2015. Kaplan-Meier analyses were used to calculate the cumulative mortality. Cox proportional hazard models and 1:1 propensity score matching (PSM) were used to evaluate the effects of T. marneffei infection on mortality of HIV/AIDS patients.

RESULTS

In total, 6791 HIV/AIDS patients were included, 1093 of them (16.1%) with documented T. marneffei co-infection. The mortality of T. marneffei-infected patients (25.0 per 100 person-months, 95% CI 21.5-26.7) was the highest among all AIDS-associated complications and was significantly higher than that of T. marneffei-uninfected HIV/AIDS patients (13.8 per 100 person-months, 95% CI 12.5-15.1; adjusted hazard ratio (AHR) 1.80, 95% CI 1.48-2.16). The results using PSM were similar (AHR 4.52 95% CI 2.43-8.42). The mortality of T. marneffei-infected patients was also significantly higher than that of patients without any complications. When stratified by demographic characteristics, T. marneffei infection has higher mortality risk in all stratifications. Co-infection with T. marneffei carries a higher mortality risk in patients at any CD4⁺ T-cell count.

CONCLUSIONS

Talaromyces marneffei infection is commonly found in hospitalized HIV/AIDS patients in southern China and was associated with a higher mortality rate than most HIV-associated complications. These results highlight the need for improved diagnosis, treatment and prevention of infection by this neglected fungal pathogen in southern China.

Characteristics associated with the consumption of malted drinks among Malaysian primary school children: findings from the MyBreakfast study

BACKGROUND

The consumption of beverages contributes to diet quality and overall nutrition. Studies on malted drinks, one of the widely consumed beverage choices among children in Asia, however, have received limited attention. This study aimed to examine the prevalence of malted drink consumption and explored associations of sociodemographic characteristics, nutrient intakes, weight status and physical activity levels with malted drink consumption among primary school children in Malaysia.

METHODS

Data for this analysis were from the MyBreakfast Study, a national cross-sectional study conducted from April to October 2013 throughout all regions in Malaysia. A total of 2065 primary school children aged 6 to 12 years were included in the present analysis. Data on two days 24-h dietary recall or record, anthropometry, physical activity and screen time were recorded. Associations between malted drink consumption and related factors were examined using binary logistic regression, adjusting for region, area, gender, ethnicity and household income.

RESULTS

Among children aged 6 to 12 years, 73.5% reported consuming malted drinks for at least once per week. Consumption of malted drinks was significantly associated with region (χ(2) = 45.64, p < 0.001), gender (χ(2) = 4.41, p = 0.036) and ethnicity (χ(2) = 13.74, p = 0.008). Malted drink consumers had similar total energy intake but higher micronutrient intakes compared to non-consumers. High physical activity level (OR = 1.77, 95% CI = 1.06, 2.99) and lower screen time during weekends (OR = 0.93, 95% CI = 0.86, 0.99) were independently associated with malted drink consumption among 6 to 9 year-old children, but not among 10 to 12 year-old children. No association was observed between malted drink consumption and weight status.

CONCLUSIONS

Malted drink consumption is prevalent among Malaysian primary school children, particularly higher among boys, indigenous children and those who lived in the East Coast region of Malaysia. Consuming malted drinks is associated with higher micronutrient intakes and higher levels of physical activity, but not with body weight status.

Whole Grain Intakes in the Diets Of Malaysian Children and Adolescents--Findings from the MyBreakfast Study

Background

Diets rich in whole grain are associated with several health benefits. Little is known however, about whole grain consumption patterns in Malaysia. The aim of this study was to assess whole grain intakes and dietary source in Malaysian children and adolescents.

Methods

This analysis is from the MyBreakfast study, a national cross sectional study investigating eating habits among primary and secondary school children throughout Malaysia, conducted in 2013. Children (n = 5,165) and adolescents (n = 2,947) who completed two days of dietary assessment using a food record or recall respectively were included. The whole grain content of foods was estimated mainly through the use of quantitative ingredient declarations on food labels. All wholegrain foods were considered irrespective of the amount of whole grain they contained.

Results

Overall, only 25% of children and 19% of adolescents were wholegrain consumers. Mean daily intakes in the total sample were 2.3g/d (SD 5.8g/d) in children and 1.7g/d (SD 4.7g/d) in adolescents and in the consumer’s only sample, mean intakes reached 9.1g/d (SD 8.6) and 9.2g/d (SD 7.1g/d) respectively. Wheat was the main grain source of whole grain while ready to eat breakfast cereals and hot cereals were the main food contributors. Less than 3% of the children and adolescents reached the US quantitative whole grain recommendation of 48g/day.

Conclusion

Whole grain is consumed by only a minority of Malaysian children and adolescents and even among consumers, intakes are well below recommendations. Efforts are needed to firstly understand the barriers to whole grain consumption among Malaysian children in order to design effective health promotion initiatives to promote an increase in whole grain consumption.

Gankyrin facilitates follicle-stimulating hormone-driven ovarian cancer cell proliferation through the PI3K/AKT/HIF-1α/cyclin D1 pathway

Gankyrin is a regulatory subunit of the 26kD proteasome complex. As a novel oncoprotein, gankyrin is expressed aberrantly in cancers from several different sites and has been shown to contribute to oncogenesis in endometrial and cervical carcinomas. Neither gankyrin's contribution to the development of epithelial ovarian cancer nor its interaction with follicle-stimulating hormone (FSH)-driven proliferation in ovarian cancer has been studied. Here we have found that gankyrin is overexpressed in ovarian cancers compared with benign ovarian cystadenomas and that gankyrin regulates FSH upregulation of cyclin D1. Importantly, gankyrin regulates PI3K/AKT signaling by downregulating PTEN. Prolonged AKT activation by FSH stimulation of the FSH receptor (FSHR) promotes gankyrin expression, which, in turn, enhances AKT activation by inhibiting PTEN. Overexpression of gankyrin decreases hypoxia inducible factor-1α (HIF-1α) protein levels, but has little effect on HIF-1α mRNA levels, which could be attributed to gankyrin mediating HIF-1α protein stability via the ubiquitin-proteasome pathway. Reduction in HIF-1α protein stability led to attenuation of the binding with cyclin D1 promoter, resulted in abolishment of the negative regulation of cyclin D1 by HIF-1α, which promotes proliferation of ovarian cancer cells. Our results document that gankyrin regulates HIF-1α protein stability and cyclin D1 expression, ultimately mediating FSH-driven ovarian cancer cell proliferation.

Evidence that a novel quaternary compound and its organic N-chloramine derivative do not select for resistant mutants of Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is well known for causing hospital-acquired infections that are often difficult to treat because of its high intrinsic and acquired resistance to antibiotics. Resistance-nodulation-division (RND) efflux pumps are the major contributors to the intrinsic multidrug resistance (MDR) in this organism. Various biocides used in hospital settings have been shown to select for RND-pump-overexpressing mutants of P. aeruginosa that show cross-resistance to clinically relevant antibiotics. Therefore, finding biocides that do not select for multidrug-resistant mutants is important in controlling the spread of bacteria such as P. aeruginosa.

AIM

To evaluate the potential of a novel quaternary ammonium compound and its N-chloramine derivative in selecting for MDR mutants of P. aeruginosa.

METHODS

P. aeruginosa PA01 was cultured in the presence of increasing concentrations of the quaternary ammonium compound and its N-chloramine derivative respectively, and one mutant each selected. Susceptibility of the mutants to both compounds as well as antibiotics was tested. Susceptibility of P. aeruginosa strains with deletions in RND pumps was also tested for both compounds to determine whether they are a substrate of these pumps. Expression of mexB, mexD, and mexY genes in the mutants was analysed using quantitative reverse transcriptase-polymerase chain reaction to determine whether the compounds can select for pump-overexpressing mutants.

FINDINGS

We show that whereas both compounds can be pumped by the MexCD-OprJ pump, they neither select for mutants that overexpress RND pumps nor for mutants that display cross-resistance to antibiotics.

CONCLUSION

These compounds are promising candidates to be used as disinfectants in hospital settings.

Identification of reference microRNAs for quantitative expression analysis in porcine peripheral blood mononuclear cells treated with polyinosinic-polycytidylic acid

Peripheral blood mononuclear cells (PBMCs) are clinically important cells. Detection of microRNAs (miRNAs) expression in PBMCs can be useful for miRNA biomarker discovery for various diseases. Quantitative real-time PCR (qRT-PCR) has become an important method used for measuring miRNAs expression. However, the reliability of qRT-PCR data critically depends on proper selection of reference genes. Here, we performed qRT-PCR to quantify the expression levels of nine miRNAs (Ssc-miR-16, Hsa-miR-25, Ssc-miR-34a, Hsa-miR-93, Bta-miR-92b, Ssc-miR-103, Ssc-miR-106a, Ssc-miR-128 and Ssc-miR-107) and one small nuclear RNA (U6) in PBMCs treated with polyinosinic-polycytidylic acid [poly (I:C)] that widely used for simulating viral infection. We used the four statistical algorithms (GeNorm 3.5, NormFinder, BestKeeper and comparative ∆ Ct method) to evaluate gene expression stability and observed that Ssc-miR-34a was the best single reference gene and the pair of Ssc-miR-107 and Ssc-miR-103 was the best combination of reference miRNAs for porcine PBMCs treated with poly (I:C). Our study shows the first evidence of careful selection of reference miRNAs in porcine PBMCs and maybe helpful for discovering miRNA biomarkers for double-stranded RNA-induced disease.

Lethal intratumoral haemorrhages of brain metastases during radiosurgery: case reports and literature review

Gamma Knife surgery (GKS) is an effective and important treatment modality in the management of brain metastases. The short-term complication rate is low and the tumour control rate high. Complications caused by acute radiation-induced oedema are rare and usually benign. In this article, two cases of lethal haemorrhagic event immediately following GKS are described from two centres, which had prompted us to review the literature.

OS057. Pathophysiological role of elevated tissue transglutaminase in autoantibody-induced features of preeclampsia in pregnant mice

INTRODUCTION

Preeclampsia (PE) is highly associated with the presence of autoantibodies that activate the major angiotensin receptor, AT1R. These autoantibodies (termed AT1-AA) cause most features of PE when introduced into pregnant mice and are believed to contribute to disease pathogenesis. Tissue transglutaminase (tTG) is a prominent member of a family of enzymes that crosslink proteins by catalyzing the formation of an isopeptide bond between the amide group of glutamine and the free amino group of lysine and is believed to play a role in AT1R activation.

OBJECTIVES

To test the hypothesis that tTG plays a role in autoantibody-mediated AT1R activation and thereby contributes to the pathophyhsiology of PE.

METHODS

Western blotting was used to quantify tTG in placentas of normotensive pregnant women and those with PE. Immunohistochemistry was used to determine cellular localization of tTG, AT1R and glutamyl-lysine isopeptides in placenta tissue. Co-immunoprecipitation experiments were used to explore the possible association of tTG and AT1R. Finally, in an effort to determine the role of tTG in AT1-AA-induced features of PE in vivo, we treated autoantibody-injected pregnant mice with cystamine, a potent tTG inhibitor.

RESULTS

Western blot analysis showed elevated tTG in placentas of women with PE. Immunohistochemical analysis revealed that increased levels of tTG, glutamyl-lysineisopeptides, AT1R co-localized in the microvillous membrane of PE placentas. Immunoprecipitation of tTG from human trophoblast cell (HTR) lysates resulted in the co-immunoprecipitation of AT1R, thereby providing evidence for an interaction between tTG and AT1R in HTR cells. Finally, we found that cystamine treatment significantly attenuated key features associated with PE including hypertension and proteinuria in the PE-IgG-injected pregnant mice.

CONCLUSION

Taken together, we identified a previously unrecognized role of elevated tTG in PE likely by activating or stabilizing AT1Rs. These studies provide novel mechanisms of autoantibody-induced AT1R activation by elevated placental tTG, highlight the role of tTG in the pathogenesis of PE and suggest novel therapeutic strategies for the disease.

Comparing T2 and T2–T3 ablation in thoracoscopic sympathectomy for palmar hyperhidrosis: a randomized control trial

BACKGROUND

Thoracoscopic sympathectomy is a useful therapeutic option for palmar hyperhidrosis. Surgeons differ in the level of the sympathetic chain ablated. This study aimed to compare the blockade of the T2 with levels T2 and T3 to verify the effectiveness of different ablation levels in relieving hyperhidrosis symptoms.

METHODS

For patients undergoing bilateral thoracoscopic sympathectomy for palmar hyperhidrosis, T2-T3 ablation is performed bilaterally. In our series, 25 consecutive patients were blindly randomized to undergo unilateral T2 and T3 ablation followed by contralateral ablation of level T2 only. The patients were followed up and analyzed for comparison of symptoms bilaterally, compensatory hyperhidrosis, and levels of satisfaction postoperatively.

RESULTS

The study group consisted of 25 patients with a male:female ratio of 3:2 and a mean age of 32 years (range, 19-50 years). The mean operative time was 35 min. The patients were followed up for a mean period of 23 months (range, 2-65 months). All 25 patients confirmed that their palmar sweating resolved postoperatively, with both palms equally dry. Of the 25 patients, 20 (80%) complained of compensatory hyperhidrosis, which also was bilaterally symmetric. The areas involved were trunk (80%), lower limbs (32%), and armpits (12%). Overall, 80% of the patients were very satisfied with the procedure. The remaining 20% experienced mild to moderate compensatory hyperhidrosis, which did not seem to affect their lifestyle.

CONCLUSION

The findings show that T2 ablation in thoracoscopic sympathectomy for palmar hyperhidrosis is as effective as T2-T3 ablation in terms of symptomatic relief, recurrence, compensatory hyperhidrosis, and patient satisfaction.

Growth-promoting effect of recombinant human growth hormone and stanozolol in girls with Turner syndrome

Ten girls with Turner syndrome were treated with a combination therapy of recombinant human growth hormone (R-hGH) and low dose stanozolol for a period of 8 to 36 months. The results showed that when compared with the growth rate before the treatment, the growth rates after treatment with R-hGH and stanozolol showed a sustained increase, reaching 9.0 +/- 1.9 cm/year during the first year of treatment; the height age increase by 2.5 +/- 0.8 years while the bone age increase were 1.0 +/- 0.7 years; and the predicted final adult height at the end of the first year of the treatment increased to 149.4 +/- 6.1 cm compared to their original mean of 142.8 +/- 4.2 cm. We are led to conclude that therapy with R-hGH in combination with stanozolol can increase the growth velocity and significantly increase the predicted adult height of children with Turner syndrome.

Galactose metabolism in mice with galactose-1-phosphate uridyltransferase deficiency: sucklings and 7-week-old animals fed a high-galactose diet

Mice deficient in galactose-1-phosphate uridyltransferase (GALT) demonstrate abnormal galactose metabolism but no obvious clinical phenotype. To further dissect the pathways of galactose metabolism in these animals, galactose oxidation and metabolite levels were studied in 16-day-old sucklings and the effect of a 4 week prior exposure to a 40% glucose or 40% galactose diet was determined in 7-week-old mice. Suckling GALT-deficient (G/G) mice slowly oxidized [1-14C]galactose to 14CO2, 4.0% of the dose when fed and 7.9% when fasted compared to normal animals 38.3 and 36.4% in 4 h, respectively. Plasma of G/G sucklings contained 11.1 mM galactose and erythrocyte galactose 1-phosphate levels were 28.2 and 31.9 mg/dl packed cells. Galactose, galactitol, galactonate, and galactose 1-phosphate were found in G/G suckling mouse tissues. The tissue galactose concentrations were 10% or less of that in plasma, suggesting that there was limited cellular entry of galactose. In 7-week-old fasted mice with 4 weeks prior exposure to glucose or galactose-containing diet, 4-h oxidation was 12.9 and 15.0% of the administered radiolabeled galactose, respectively. Normal animals oxidized 33.9 and 37.9% of the dose when fed the same diets, respectively. The ability of G/G mice to oxidize galactose in the absence of GALT activity suggests the presence of alternate metabolic pathways for galactose disposition. G/G mice fed the galactose-free 40% glucose diet had erythrocyte galactose 1-phosphate levels ranging from 6.4 to 17.7 mg/dl packed cells and detectable galactose and galactose metabolites in tissues, suggesting that these animals endogenously produced galactose. The plasma of 40% galactose-fed G/G mice contained 9.1 mM galactose with red blood cell galactose 1-phosphate averaging 43.6 mg/dl. Tissues of these animals also contained high levels of galactose and galactose 1-phosphate. Liver contained over 4 micromol/g galactonate but little galactitol. Despite the elevated galactose and galactose 1-phosphate, the animals tolerated the high-galactose diet and were indistinguishable from normal animals, exhibiting no manifestations of galactose toxicity seen in human GALT-deficient galactosemia. The data suggest that high galactose 1-phosphate levels do not cause galactose toxicity and that high galactitol in combination with galactose 1-phosphate may be a prerequisite. Absence of GALT appears necessary but insufficient to produce human galactosemic phenotype.

In vivo evidence of brain galactitol accumulation in an infant with galactosemia and encephalopathy

In a newborn infant with galactose-1-phosphate uridyltransferase deficiency and encephalopathy, brain magnetic resonance imaging revealed cytotoxic edema in white matter. Using in vivo proton magnetic resonance spectroscopy, we detected approximately 8 mmol galactitol per kilogram of brain tissue, an amount potentially relevant to the pathogenesis of brain edema.

Plasma galactose and galactitol concentration in patients with galactose-1-phosphate uridyltransferase deficiency galactosemia: determination by gas chromatography/mass spectrometry

The plasma concentration of galactose and galactitol was measured in 27 patients with galactose-1-phosphate uridyltransferase (GALT) deficiency galactosemia on a lactose-restricted diet, 17 infants on lactose-free formula, and 21 infants and children on a normal diet, by a newly devised isotope dilution gas chromatograph/mass spectrometry (GC/MS) method. The method was linear in the range of 0.1 to 10 micromol/L for galactose and 1 to 20 micromol/L for galactitol with good reproducibility and a coefficient of variation less than 3%. The mean plasma galactose in 15 patients who were homozygous for the most common Q188R mutation of the GALT gene was 2.72 +/- 0.70 micromol/L (mean +/- SE) with a range of 0.58 to 3.98 in specimens obtained at regular clinic visits. In 12 patients with other GALT mutations, it was 2.45 +/- 0.75 micromol/L. The mean value in nongalactosemic subjects on lactose-free formula was 0.52 +/- 0.08 micromol/L, with a range of 0.12 to 1.25. The range in 21 normal subjects without diet restriction was 0.11 to 6.33 micromol/L, with a mean of 1.48 +/- 0.32. The plasma galactitol level was 11.63 +/- 0.46 and 10.85 +/- 1.38 micromol/L in the 2 galactosemic groups. There was no relationship between plasma galactose and galactitol levels, with variable ratios of the two substances in the galactosemic patients. Galactitol was not detectable in the plasma of normal subjects. The red blood cell galactose-1-phosphate level was also measured in the galactosemic patients, and no relationship between plasma galactose and red blood cell galactose-1-phosphate was found. The galactose-1-phosphate concentration was 28 to 54 times higher than the ambient galactose. The low galactose concentration in the plasma of galactosemics on galactose-restricted diets in relation to the higher plasma galactitol and red blood cell galactose-1-phosphate is a metabolic enigma. The ability to measure plasma galactose accurately presents a new way of characterizing the galactosemic patient and the levels monitored over time may provide insight into the development of long-term complications associated with the disorder.

Galactose metabolism by the mouse with galactose-1-phosphate uridyltransferase deficiency

The ability of mice deficient in galactose-1-phosphate uridyltransferase (GALT) to metabolize galactose was determined in animals weaned to a mouse chow diet for a 4-wk period. When given [14C]galactose intraperitoneally, these animals slowly oxidized the sugar, excreting only 5.5% of the dose as 14CO2 in 4 h, whereas normal animals excreted 39.9%. These results mimic those seen in human galactosemic patients given isotopic galactose. When given 10 micromol of [1-13C]galactose, normal animals excrete small amounts of labeled galactose and galactonate but no galactitol in urine whereas GALT-deficient mice excrete significant amounts of all of these as labeled compounds in urine. When challenged with galactose, only about 20% of the dose is excreted in urine, and even on the chow diet, significant amounts of galactose, galactonate, and galactitol are excreted in urine. These compounds are also found to be present in liver, kidney, and brain, except that galactonate is not found in brain. Galactose-1-phosphate accumulates in red blood cells to levels found in humans exposed to large amounts of galactose, and galactose-1-phosphate is found in increased amounts in liver, kidney, and brain of GALT-deficient animals. There was no difference in the hepatic concentration of uridine diphosphate galactose and uridine diphosphate glucose between normal and GALT-deficient mice. The explanation for the presence of galactose and its conversion products in tissues and urine of affected mice appears to be related to the presence of approximately 1.75% of galactose-containing carbohydrates in the chow, which becomes bioavailable to mice. Despite the presence of galactose and its metabolites in tissues and urine and impaired ability to oxidize the sugar, the GALT-deficient animals are indistinguishable from normal animals and do not exhibit the phenotype of humans with GALT-deficiency galactosemia.

Apparent galactose appearance rate in human galactosemia based on plasma [(13)C]galactose isotopic enrichment

Determination of endogenous galactose formation in galactosemic subjects provides important information in understanding the etiology of the long-term complications. To accomplish this task a sensitive method for measurement of isotopic enrichment of plasma galactose was developed. The aldononitrile pentaacetate derivative of galactose was utilized for gas chromatography/mass spectrometry analysis. Using a phenyl-methylsilicone capillary column, adequate separation of galactose from glucose was obtained by temperature programming of the chromatography. The specific fragmentation pattern of m/z 212, 225, 314 from d-[(12)C]galactose and m/z 213, 226, 315 from l-[(13)C]galactose was used for the galactose enrichment measurement by atom percent excess (APE). There was good correlation between expected enrichment and determined APEs at galactose concentrations of 1, 2, and 5 micromol/L with a coefficient of variation ranging from 0.22 to 7.17%. The method provides an accurate estimation of plasma [(13)C]galactose enrichment from which the galactose production rate can be calculated. The steady-state plasma l-[(13)C]galactose isotopic enrichment of three individuals with galactosemia, two males ages 33 and 13, and one female age 9, during constant infusion of l-[(13)C]galactose was 55, 41, and 55%, allowing the estimation of the apparent galactose appearance rate of 0.62, 1.09, and 0.82 mg/kg/h, respectively. The reanalysis of three previous studies by the present method found that APE values determined by the method then employed, butylboronate acetate derivatization, were systemically lower than those determined with aldononitrile pentaacetate derivatization, making for an overestimation of the apparent galactose appearance rate. The small plasma sample volumes needed make it feasible to perform these studies in infants and young children with galactosemia.

A mouse model of galactose-induced cataracts

Galactokinase (GK; EC 2.7.1.6) is the first enzyme in the metabolism of galactose. In humans, GK deficiency results in congenital cataracts due to an accumulation of galactitol within the lens. In an attempt to make a galactosemic animal model, we cloned the mouse GK gene (Glk1) and disrupted it by gene targeting. As expected, galactose was very poorly metabolized in GK-deficient mice. In addition, both galactose and galactitol accumulated in tissues of GK-deficient mice. Surprisingly, the GK-deficient animals did not form cataracts even when fed a high galactose diet. However, the introduction of a human aldose reductase transgene into a GK-deficient background resulted in cataract formation within the first postnatal day. This mouse represents the first mouse model for congenital galactosemic cataract.

An observation on the mimic ecology of the oncomelania hupensis in three-Gorge-reservoir areas

According to the modulation of three-gorge-reservoir water level, the two observation spots were established at Gaoyang Town and Jianshe Village in Xingshan County of Hubei Province in order to observe the survival and reproduction of the oncomelania under different ecological conditions. Our one-year observation revealed that most settled oncomelania died between June and August in the year and only a few of them survived the winter. The oncomelania hupensis's survival rate in group I, II, III settled in Gaoyang Town was 10%, 1%, 0%, respectively, and the oncomelania Sichuan's 12.5%, 22.5%, 13.5%. The rates obtained from spots in Jianshe Village is 0%, 2%, 0% and 9.5%, 19%, 3%, respectively. The survival rate of oncomelania Sichuan was higher than that of the oncomelania hupensis in the two spots. After draining the feeding pools, the soil samples were harvested and used for egg-hatching. The numbers of eggs that hatched in group I, II in Gaoyang were 1 and 2, respectively. The young oncomelania were found in each spot pool after the drainage, suggesting that the local condition is favorable to the oncomelania and the mating season of each group oncomelania is from April to August with the most active mating time being from May to June.

Determination of [(13)C]galactose enrichment in human plasma by gas chromatography/positive chemical ionization tandem mass spectrometry

Galactosemia is a potentially fatal disease resulting from a deficiency of galactose-1-phosphate uridyl transferase. In order to perform mechanistic studies designed to elucidate further the etiology of the disease, we required a method to monitor (13)C enrichment in plasma galactose following a single oral dose or intravenous infusion of [1-(13)C]galactose. Determinations of plasma [(13)C]galactose enrichment requires methodology with extremely high specificity because of potential interference from other low molecular mass plasma constituents and from glucose, an isomer which is present in much higher concentrations. We have developed a method based on gas chromatography/positive chemical ionization tandem mass spectrometry (GC/PCI-MS/MS) for the precise and accurate determination of plasma [(13)C]galactose enrichment. The method employed a pentaacetylaldononitrile derivative of galactose in order to improve its GC and MS characteristics. Peak areas resulting from the transitions m/z 328 --> 106 and m/z 329 --> 107 were used to quantify the relative abundance of labeled and unlabeled galactose. Validation of the method was performed by determination of the precision and accuracy over a wide range of galactose concentrations and (13)C enrichments. The GC/PCI-MS/MS method was able to determine accurately enrichments at galactose concentrations down to 0.8 microM in the presence of 4 mM glucose, making it both highly selective and the most sensitive method currently available.

Urine and plasma galactitol in patients with galactose-1-phosphate uridyltransferase deficiency galactosemia

Urinary excretion of galactitol was determined in 95 normals (N/N), 67 galactosemic (G/G), and 39 compound heterozygotes for the Duarte and galactosemia genotype (D/G). Galactitol excretion is age-dependent in both normal individuals and patients with classic galactosemia on lactose-restricted diets. In galactosemic patients who are homozygous for the Q188R mutation, urinary galactitol levels were fivefold to 10-fold higher than those of normal subjects of comparable age. All but a few patients with classic galactosemia with the Q188R mutation and another mutant G allele had urinary excretion comparable to the Q188R homozygous patients. African-American galactosemic patients with the S135L mutation of the galactose-1-phosphate uridyltransferase (GALT) gene also excreted abnormal quantities of galactitol. Most subjects with a Duarte allele and a G allele excrete normal amounts of the sugar alcohol. There is a correlation between galactitol excretion and red blood cell (RBC) galactose-1-phosphate (gal-1-P). Plasma galactitol was also elevated in galactosemic patients (3.4 to 23.2 micromol/L; undetectable in normal individuals). In contrast to the decrease in urinary galactitol with age, plasma levels remain in a narrow concentration range with no significant difference with age. Urine and plasma galactitol distinguish galactosemic patients from normals. In addition, urinary galactitol excretion may be an important parameter for the assessment of steady-state galactose metabolism in galactosemia.

Nontraumatic atlanto-occipital and atlantoaxial rotatory subluxation: case report

OBJECTIVE AND IMPORTANCE

Concomitant atlantoaxial and atlanto-occipital subluxation resulting from any cause is extremely rare. We have found only five previously reported cases and describe another, suggesting a treatment plan.

CLINICAL PRESENTATION

A 13-year-old female patient presented with a 3-month history of neck pain and decreased neck movements. All symptoms started after a localized neck infection had been treated successfully with antibiotics. There was no history of trauma. A diagnosis of postinfective atlanto-occipital and atlantoaxial rotatory subluxation was made based on a plain roentgenogram and was confirmed based on a computed tomographic scan.

INTERVENTION

The atlantoaxial and atlanto-occipital subluxation was reduced during surgery. A posterior C1-C2 fixation was performed, and the atlanto-occipital joint was stabilized by means of a halo body jacket for 3 months. One year after removal of the jacket, all subluxation remained reduced and the patient retained significant neck movement.

CONCLUSION

Disruption of the occipito-atlanto-axial complex can result from relatively minor head and neck infections and should be suspected in children with persisting neck pain and decreased neck movements. It may not be necessary to perform an occipitoaxial fusion to treat these patients, and a more limited fusion may be successful.

Gas chromatographic-mass spectrometric metabolic profiling of patients with fatal infantile mitochondrial myopathy with de Toni-Fanconi-Debré syndrome

The metabolic profiles of three patients with fatal infantile mitochondrial myopathy with de Toni-Fanconi-Debré syndrome were studied by simultaneous analysis, after urease treatment of urinary organic acids, carbohydrates, polyols and amino acids using gas chromatography/mass spectrometry (GC/MS). All three patients persistently showed lactic aciduria, phosphaturia, glucosuria and generalized amino aciduria. This abnormal urinary metabolic profile was observed before the onset of any clinical symptoms, indicating that chemical diagnosis may be done presymptomatically. In one patient, the concentration of lactate increased in parallel with the severity of the clinical condition, whereas the urinary levels of 3-hydroxybutyrate, amino acids and glucose fluctuated and showed only a general tendency to increase with the clinical course. The above results suggest that simultaneous GC/MS analyses, without fractionation, of urinary metabolites facilitate not only the early chemical diagnosis either before or after the first onset, but also follow-up studies, providing an important index for the evaluation of the severity and clinical course in patients with this disorder.

Clinical significance of multiple hypothalamic-pituitary functions assessment in patients with Turner's syndrome

Hypothalamic-pituitary functions in 26 cases of Turner syndrome were assessed with a combined stimulation test. The results showed that the peak GH levels of 12 cases were less than 10 micrograms/L; 3 patients were demonstrated as having an even TSH response, while another one with a delayed TSH peak, and other 4 had high basal values and consistent exaggerated TSH responses to TRH; all patients showed increased basal and peak LH and FSH levels but 5, whose LH and FSH secretion patterns were similar to normal. 12 cases have been treated with individualized protocols and followed up for 12 months or more, of them the growth velocity all increased, especially those with hypothyroidism or with a BA less than 13. It is suggested that multiple functions of hypothalamic-pituitary axis in Turner patients be evaluated as early as possible, in order that proper treatment could be adopted and their growth and development improved.

Hypothalamic-pituitary function assessment in children by a combined stimulation test

We utilized a combined stimulation test using insulin, thyrotropin-releasing hormone, gonadotropin-releasing hormone and levodopa to assess multiple pituitary hormones including growth hormone, thyrotropin, prolactin and gonadotropins in 32 children of short stature and 18 girls with early appearance of puberty. It was found that this combined stimulation test can assess multiple hormone responses with satisfactory results in a single 90-min test. Compared with any of those laborious classic stimulation tests alone, it is easier to be carried out and willingly accepted by children.

The screening diagnosis of tetrahydrobiopterin deficient phenylketonuria

Since 1990, 20 diagnostically confirmed phenylketonuria (PKU) patients have been screened with a tetrahydrobiopterin (BH4) loading test, in which plasma phenylalanine and urinary pterin metabolites were investigated, ind activity of dihydropteridine reductase (DHPR) was determined as well. The results showed that there was no statistical difference between the concentrations of plasma phenylalanine before and after BH4 (20mg/kg) administration in all patients, and values of urinary neopterin and biopterin were within the range of classic PKU. All patients but one had normal activity of DHPR in red cells. This suggests that incidence of BH4 deficiency in PKU patients amounts to five percent (1/20) which is almost the same as reported abroad.