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1.
Quant Plant Biol ; 5: e5, 2024.
Article in English | MEDLINE | ID: mdl-38774130

ABSTRACT

Plant growth requires the integration of internal and external cues, perceived and transduced into a developmental programme of cell division, elongation and wall thickening. Mechanical forces contribute to this regulation, and thigmomorphogenesis typically includes reducing stem height, increasing stem diameter, and a canonical transcriptomic response. We present data on a bZIP transcription factor involved in this process in grasses. Brachypodium distachyon SECONDARY WALL INTERACTING bZIP (SWIZ) protein translocated into the nucleus following mechanostimulation. Classical touch-responsive genes were upregulated in B. distachyon roots following touch, including significant induction of the glycoside hydrolase 17 family, which may be unique to grass thigmomorphogenesis. SWIZ protein binding to an E-box variant in exons and introns was associated with immediate activation followed by repression of gene expression. SWIZ overexpression resulted in plants with reduced stem and root elongation. These data further define plant touch-responsive transcriptomics and physiology, offering insights into grass mechanotranduction dynamics.

2.
Astron Astrophys ; 6372020 May.
Article in English | MEDLINE | ID: mdl-32565548

ABSTRACT

CONTEXT: Sulphur is one of the most abundant elements in the Universe. Surprisingly, sulphuretted molecules are not as abundant as expected in the interstellar medium and the identity of the main sulphur reservoir is still an open question. AIMS: Our goal is to investigate the H2S chemistry in dark clouds, as this stable molecule is a potential sulphur reservoir. METHODS: Using millimeter observations of CS, SO, H2S, and their isotopologues, we determine the physical conditions and H2S abundances along the cores TMC 1-C, TMC 1-CP, and Barnard 1b. The gas-grain model Nautilus is used to model the sulphur chemistry and explore the impact of photo-desorption and chemical desorption on the H2S abundance. RESULTS: Our modeling shows that chemical desorption is the main source of gas-phase H2S in dark cores. The measured H2S abundance can only be fitted if we assume that the chemical desorption rate decreases by more than a factor of 10 when n H > 2 × 104. This change in the desorption rate is consistent with the formation of thick H2O and CO ice mantles on grain surfaces. The observed SO and H2S abundances are in good agreement with our predictions adopting an undepleted value of the sulphur abundance. However, the CS abundance is overestimated by a factor of 5 - 10. Along the three cores, atomic S is predicted to be the main sulphur reservoir. CONCLUSIONS: The gaseous H2S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H2S. The behavior of the observed H2S abundance suggests a changing desorption efficiency, which would probe the snowline in these cold cores. Our model, however, highly overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, we can only conclude that our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.

3.
New Phytol ; 227(6): 1709-1724, 2020 09.
Article in English | MEDLINE | ID: mdl-32112414

ABSTRACT

Plants are continuously exposed to diurnal fluctuations in light and temperature, and spontaneous changes in their physical or biotic environment. The circadian clock coordinates regulation of gene expression with a 24 h period, enabling the anticipation of these events. We used RNA sequencing to characterize the Brachypodium distachyon transcriptome under light and temperature cycles, as well as under constant conditions. Approximately 3% of the transcriptome was regulated by the circadian clock, a smaller proportion than reported in most other species. For most transcripts that were rhythmic under all conditions, including many known clock genes, the period of gene expression lengthened from 24 to 27 h in the absence of external cues. To functionally characterize the cyclic transcriptome in B. distachyon, we used Gene Ontology enrichment analysis, and found several terms significantly associated with peak expression at particular times of the day. Furthermore, we identified sequence motifs enriched in the promoters of similarly phased genes, some potentially associated with transcription factors. When considering the overlap in rhythmic gene expression and specific pathway behavior, thermocycles was the prevailing cue that controlled diurnal gene regulation. Taken together, our characterization of the rhythmic B. distachyon transcriptome represents a foundational resource with implications in other grass species.


Subject(s)
Brachypodium , Brachypodium/genetics , Circadian Rhythm/genetics , Cues , Gene Expression Regulation , Gene Expression Regulation, Plant , Temperature
4.
Endocr Connect ; 8(2): 100-110, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30668521

ABSTRACT

Disorders of sex development (DSDs) are a diverse group of conditions where the chromosomal, gonadal or anatomical sex can be atypical. The highly heterogeneous nature of this group of conditions often makes determining a genetic diagnosis challenging. Prior to next generation sequencing (NGS) technologies, genetic diagnostic tests were only available for a few of the many DSD-associated genes, which consequently had to be tested sequentially. Genetic testing is key in establishing the diagnosis, allowing for personalised management of these patients. Pinpointing the molecular cause of a patient's DSD can significantly impact patient management by informing future development needs, altering management strategies and identifying correct inheritance pattern when counselling family members. We have developed a 30-gene NGS panel, designed to be used as a frontline test for all suspected cases of DSD (both 46,XX and 46,XY cases). We have confirmed a diagnosis in 25 of the 80 patients tested to date. Confirmed diagnoses were linked to mutations in AMH, AMHR2, AR, HSD17B3, HSD3B2, MAMLD1, NR5A1, SRD5A2 and WT1 which have resulted in changes to patient management. The minimum diagnostic yield for patients with 46,XY DSD is 25/73. In 34/80 patients, only benign or likely benign variants were identified, and in 21/80 patients only variants of uncertain significance (VOUS) were identified, resulting in a diagnosis not being confirmed in these individuals. Our data support previous studies that an NGS panel approach is a clinically useful and cost-effective frontline test for patients with DSDs.

5.
Plant J ; 96(3): 532-545, 2018 11.
Article in English | MEDLINE | ID: mdl-30054951

ABSTRACT

Grass biomass is comprised chiefly of secondary walls that surround fiber and xylem cells. A regulatory network of interacting transcription factors in part regulates cell wall thickening. We identified Brachypodium distachyon SECONDARY WALL ASSOCIATED MYB1 (SWAM1) as a potential regulator of secondary cell wall biosynthesis based on gene expression, phylogeny, and transgenic plant phenotypes. SWAM1 interacts with cellulose and lignin gene promoters with preferential binding to AC-rich sequence motifs commonly found in the promoters of cell wall-related genes. SWAM1 overexpression (SWAM-OE) lines had greater above-ground biomass with only a slight change in flowering time while SWAM1 dominant repressor (SWAM1-DR) plants were severely dwarfed with a striking reduction in lignin of sclerenchyma fibers and stem epidermal cell length. Cellulose, hemicellulose, and lignin genes were significantly down-regulated in SWAM1-DR plants and up-regulated in SWAM1-OE plants. There was no reduction in bioconversion yield in SWAM1-OE lines; however, it was significantly increased for SWAM1-DR samples. Phylogenetic and syntenic analyses strongly suggest that the SWAM1 clade was present in the last common ancestor between eudicots and grasses, but is not in the Brassicaceae. Collectively, these data suggest that SWAM1 is a transcriptional activator of secondary cell wall thickening and biomass accumulation in B. distachyon.


Subject(s)
Brachypodium/genetics , Plant Proteins/genetics , Biomass , Brachypodium/growth & development , Brassicaceae/genetics , Brassicaceae/growth & development , Cell Wall/metabolism , Cellulose/metabolism , Lignin/metabolism , Plant Proteins/metabolism , Polysaccharides/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
6.
Front Plant Sci ; 9: 1895, 2018.
Article in English | MEDLINE | ID: mdl-30627134

ABSTRACT

Arabidopsis thaliana CELLULOSE SYNTHASE A4/7/8 (CESA4/7/8) are three non-redundant subunits of the secondary cell wall cellulose synthase complex. Transcript abundance of these genes can vary among genotypes and expression quantitative trait loci (eQTL) were identified in a recombinant population of the accessions Bay-0 and Shahdara. Genetic mapping and analysis of the transcript levels of CESAs between two distinct near isogenic lines (NILs) confirmed a change in CESA4 expression that segregates within that interval. We sequenced the promoters and identified 16 polymorphisms differentiating CESA4Sha and CESA4Bay . In order to determine which of these SNPs could be responsible for this eQTL, we screened for transcription factor protein affinity with promoter fragments of CESA4Bay, CESA4Sha , and the reference genome CESA4Col . The wall thickening activator proteins NAC SECONDARY WALL THICKENING PROMOTING FACTOR2 (NST2) and NST3 exhibited a decrease in binding with the CESA4Sha promoter with a tracheary element-regulating cis-element (TERE) polymorphism. While NILs harboring the TERE polymorphisms exhibited significantly different CESA4 expression, cellulose crystallinity and cell wall thickness were indistinguishable. These results suggest that the TERE polymorphism resulted in differential transcription factor binding and CESA4 expression; yet A. thaliana is able to tolerate this transcriptional variability without compromising the structural elements of the plant, providing insight into the elasticity of gene regulation as it pertains to cell wall biosynthesis and regulation. We also explored available DNA affinity purification sequencing data to resolve a core binding site, C(G/T)TNNNNNNNA(A/C)G, for secondary wall NACs referred to as the VNS element.

7.
PLoS One ; 9(6): e100072, 2014.
Article in English | MEDLINE | ID: mdl-24927130

ABSTRACT

Plant growth is commonly regulated by external cues such as light, temperature, water availability, and internal cues generated by the circadian clock. Changes in the rate of growth within the course of a day have been observed in the leaves, stems, and roots of numerous species. However, the relative impact of the circadian clock on the growth of grasses has not been thoroughly characterized. We examined the influence of diurnal temperature and light changes, and that of the circadian clock on leaf length growth patterns in Brachypodium distachyon using high-resolution time-lapse imaging. Pronounced changes in growth rate were observed under combined photocyles and thermocycles or with thermocycles alone. A considerably more rapid growth rate was observed at 28°C than 12°C, irrespective of the presence or absence of light. In spite of clear circadian clock regulated gene expression, plants exhibited no change in growth rate under conditions of constant light and temperature, and little or no effect under photocycles alone. Therefore, temperature appears to be the primary cue influencing observed oscillations in growth rate and not the circadian clock or photoreceptor activity. Furthermore, the size of the leaf meristem and final cell length did not change in response to changes in temperature. Therefore, the nearly five-fold difference in growth rate observed across thermocycles can be attributed to proportionate changes in the rate of cell division and expansion. A better understanding of the growth cues in B. distachyon will further our ability to model metabolism and biomass accumulation in grasses.


Subject(s)
Brachypodium/growth & development , Circadian Clocks/physiology , Circadian Rhythm/physiology , Temperature , Brachypodium/genetics , Brachypodium/radiation effects , CLOCK Proteins/genetics , CLOCK Proteins/metabolism , Gene Expression Regulation, Developmental , Gene Expression Regulation, Plant/radiation effects , Light , Photoperiod , Plant Leaves/growth & development , Plant Leaves/metabolism , Plant Leaves/radiation effects , Time-Lapse Imaging
8.
Arch Dis Child ; 94(2): 151-2, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18562452

ABSTRACT

Children with suspected type 1 diabetes mellitus (T1DM) should have same day referral to a paediatric diabetes team. 99 children (54 male; median age 10.5 years, range 0.9-15.9 years) were diagnosed with T1DM at our hospital between January 2004 and June 2007. 27 (27.2%) presented in diabetic ketoacidosis (DKA). 37 (37.3%) required hospital admission, while the rest had ambulatory management. In 21 (21.2%) children, diagnosis was delayed >24 h (median 3.0 days, range 1-14 days) due to missed diagnosis at the local hospital (four) or by the general practitioner (seven), arranging a fasting blood glucose test (nine) and outpatient appointment requested via fax (one). Children with delayed diagnosis presented more frequently in DKA (52.3% vs 20.5%, p<0.01), with a higher median presenting HbA1c (12.3% vs 10.9%, p<0.05). There were no differences in age and sex between the delayed diagnosis and immediate referral groups. Healthcare providers need to be aware of the importance of immediate referral of children newly diagnosed with T1DM.


Subject(s)
Diabetes Mellitus, Type 1/diagnosis , Diagnostic Errors/statistics & numerical data , Adolescent , Blood Glucose/analysis , Child , Child, Preschool , Clinical Competence , Diabetes Mellitus, Type 1/blood , Diabetic Ketoacidosis/blood , Diabetic Ketoacidosis/diagnosis , England , Family Practice/standards , Female , Glycated Hemoglobin/analysis , Hospitalization/statistics & numerical data , Humans , Hydrogen-Ion Concentration , Infant , Male , Referral and Consultation/standards , Time Factors
9.
Horm Res ; 68(1): 8-10, 2007.
Article in English | MEDLINE | ID: mdl-17213729

ABSTRACT

BACKGROUND/AIMS: Although childhood obesity is a major problem, routine assessment methods do not reflect fat mass. Body mass index, which is most commonly used, gives an indication of weight for height and not a degree of adiposity. METHODS: Bioelectrical impedance and dual-energy X-ray absorptiometry (DEXA) were used in a group of obese children to assess body fat. RESULTS: Comparison between DEXA and commercial bioelectrical impedance scales in 46 children showed a highly significant correlation (R = 0.944, p < 0.001) in fat mass. Fat mass measured using bioelectrical impedance was 2.4 kg lower compared to measurement using DEXA. CONCLUSION: These bioelectrical scales may prove useful in the management of childhood obesity as they are able to provide important clinical information regarding fat mass and adiposity.


Subject(s)
Adipose Tissue , Adiposity , Electric Impedance , Obesity/diagnosis , Absorptiometry, Photon , Child , Female , Humans , Male
10.
Horm Res ; 65(1): 18-22, 2006.
Article in English | MEDLINE | ID: mdl-16357486

ABSTRACT

AIM: To assess the factors determining patient choice of GH device, and whether offering free patient choice improves compliance with GH therapy. METHODS: A prospective cross-sectional study performed on patients offered free choice of GH device in a regional growth clinic. In a subgroup having home delivery, GH compliance was assessed using ampoule counts. RESULTS: 125 patients (74 (59%) male), median (range) 9.30 (1.0-18.3) years were commenced on GH from January 2001 to March 2004, and offered free choice of device. 68 (54%) chose a needled device, and 57 (46%) needle-free. There was no statistical difference in age, sex or diagnostic category between the two groups. Light blue devices were more likely to be chosen by males (p=0.056). Questionnaires giving reasons for choosing a device were available in 40, and a further 50 gave reasons for both choosing a specific device and not choosing others. Other than choice of needled/needle-free device, the factor most likely to determine choice was 'ease of use'. Only 6 (4.8%) subsequently changed device, and compliance remained high but unchanged at approximately 90%. CONCLUSIONS: There are no specific features which determine what GH device a patient will choose. For those units offering free patient choice, a wide range of different devices should be made available.


Subject(s)
Hormone Replacement Therapy/methods , Human Growth Hormone/administration & dosage , Adolescent , Child , Child, Preschool , Choice Behavior , Cohort Studies , Female , Humans , Infant , Injections, Subcutaneous , Male , Patient Compliance , Prospective Studies
11.
Clin Endocrinol (Oxf) ; 62(2): 163-8, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15670191

ABSTRACT

OBJECTIVES: Mutations in the genes encoding the transcription factors PROP1 and POUF-1 (Pit-1) have been reported as common causes of combined pituitary hormone deficiency (CPHD), and HESX1 mutations have been identified in children with septo-optic dysplasia (SOD). There are few data on UK children. We have performed mutation analysis in a large cohort of affected children within the West Midlands region to assess the feasibility of a screening strategy for molecular diagnosis in CPHD and SOD. DESIGN AND PATIENTS: The three coding exons of PROP1, and six exons of POUF-1 in 27 children from 26 families with CPHD, and three exons of HESX1 in 23 children from 22 families with SOD were directly sequenced from a well-characterized regional cohort. RESULTS: We identified a C to T transition in exon 6 of POUF-1, resulting in a known missense mutation (R271W) in a mother and daughter from one family with CPHD. We also found a novel homozygous T to C transition in exon 6 of POUF-1, resulting in a missense mutation (F233L) in a twin with CPHD. This mutation was excluded in 100 ethnically matched control alleles. We did not identify any mutations in the PROP1 gene or HESX1. The median maternal age at delivery for the CPHD children was 27 years, compared to 21 years for the mothers of SOD children (P = 0.04). CONCLUSIONS: Mutations in POUF-1, PROP1 and HESX1 are rare causes of CPHD and SOD, respectively, in children from the West Midlands. In particular, we did not confirm the reported 'hotspot' in PROP1. A screening strategy that targets familial cases is highly likely to increase the mutation yield. The young maternal age at conception of children with SOD and potential teratogen exposure indicate the predominance of environmental factors in this condition compared with CPHD.


Subject(s)
DNA-Binding Proteins/genetics , Homeodomain Proteins/genetics , Pituitary Hormones/deficiency , Polymorphism, Genetic , Septo-Optic Dysplasia/genetics , Transcription Factors/genetics , Child , Child, Preschool , DNA Mutational Analysis , England , Female , Humans , Hypopituitarism/genetics , Hypopituitarism/pathology , Infant , Infant, Newborn , Magnetic Resonance Imaging , Male , Maternal Age , Pituitary Gland/pathology , Prospective Studies , Septo-Optic Dysplasia/pathology , Teratogens/toxicity , Transcription Factor Pit-1
12.
Acta Paediatr ; 93(12): 1663-5, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15918231

ABSTRACT

UNLABELLED: Patients with primary hypothyroidism may also have other underlying associated endocrinopathies, which are important to exclude. A 15-y-old girl presented with clinical biochemical evidence of hypothyroidism. CONCLUSION: Thyroxine replacement unmasked Addison's disease and precipitated an acute adrenal crisis. On physiological steroid replacement therapy, her "hypothyroidism" resolved.


Subject(s)
Addison Disease/complications , Addison Disease/diagnosis , Hypothyroidism/complications , Adolescent , Female , Hormone Replacement Therapy , Humans , Hypothyroidism/drug therapy , Thyroxine/therapeutic use
13.
Br J Dermatol ; 146(1): 138-40, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11852916

ABSTRACT

We report a 13-year-old girl with multiple cutaneous histiocytic lesions, precocious puberty, growth hormone deficiency and a hypothalamic tumour. We conclude that she has progressive nodular histiocytosis, but this case illustrates the difficulty in differentiating the type II histiocytoses.


Subject(s)
Histiocytosis, Non-Langerhans-Cell/complications , Hypothalamic Neoplasms/complications , Adolescent , Child , Disease Progression , Dwarfism, Pituitary/diagnosis , Dwarfism, Pituitary/etiology , Female , Histiocytosis, Non-Langerhans-Cell/diagnosis , Humans , Hypothalamic Neoplasms/diagnosis , Puberty, Precocious/diagnosis , Puberty, Precocious/etiology , Treatment Outcome
14.
Clin Endocrinol (Oxf) ; 55(2): 163-74, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11531922

ABSTRACT

OBJECTIVE: The association of idiopathic hypogonadotrophic hypogonadism (IHH) with congenital olfactory deficit defines Kallmann's syndrome (KS). Although a small proportion of IHH patients have been found to harbour defined genetic lesions, the genetic basis of most IHH cases remains to be elucidated. Genes currently recognized to be involved comprise KAL (associated with X-linked-KS), the GnRH receptor (associated with resistance to GnRH therapy), DAX 1 (associated with adrenohypoplasia congenita) and three loci also associated with obesity, leptin (OB), leptin receptor (DB) and prohormone convertase (PC1). Because of the rarity of the condition and the observation that patients are almost universally infertile without assistance, familial transmission of IHH is encountered infrequently and pedigrees tend to be small. This has constrained the ability of conventional linkage studies to identify other candidate loci for genetic IHH. We hypothesized that a systematic clinical evaluation of a large patient sample might provide new insights into the genetics of this rare disorder. Specifically, we wished to examine the following propositions. First, whether normosmic (nIHH) and anosmic (KS) forms of IHH were likely to be genetically discrete entities, on the basis of quantitative olfactory testing, analysis of autosomal pedigrees and the prevalence of developmental defects such as cryptorchidism and cleft palate. Second, whether mirror movements and/or unilateral renal agenesis were specific phenotypic markers for X-linked-KS. DESIGN AND PATIENTS: We conducted a clinical study of 170 male and 45 female IHH patients attending the endocrinology departments of three London University teaching hospitals. Approximately 80% of data were obtained from case records and 20% collected prospectively. Parameters assessed included olfaction, testicular volume, family history of hypogonadism, anosmia or pubertal delay, and history or presence of testicular maldescent, neurological, renal or craniofacial anomalies. Where possible, the clinical information was correlated with published data on genetic analysis of the KAL locus. RESULTS: Olfactory acuity was bimodally distributed with no evidence for a spectrum of olfactory deficit. Testicular volume, a marker of integrated gonadotrophin secretion, did not differ significantly between anosmic and normosmic patients, at 2.0 ml and 2.2 ml, respectively. Nevertheless, the prevalence of cryptorchidism was nearly three times greater in anosmic (70.3%, of which 75.0% bilateral) than in normosmic (23.2%, of which 43.8% bilateral) patients. Individuals with nIHH, eugonadal isolated anosmia and/or KS were observed to coexist within 6/13 autosomal IHH pedigrees. On three occasions, fertility treatment given to an IHH patient had resulted in the condition being transmitted to the resulting offspring. Mirror movements and unilateral renal agenesis were observed in 24/98 and 9/87 IHH patients, respectively, all of whom were identifiable as X-KS males on the basis of pedigree analysis and/or defective KAL coding sequence. Abnormalities of eye movement and unilateral sensorineural deafness were observed in 10/21 and 6/111 KS patients, respectively, but not in nIHH patients. DISCUSSION: Patients with IHH are almost invariably either anosmic (KS) or normosmic (nIHH), rather than exhibiting intermediate degrees of olfactory deficit. Moreover, the prevalence of cryptorchidism is nearly three times greater in KS than in nIHH despite comparable testicular volumes, suggesting a primary defect of testicular descent in KS independent of gonadotrophin deficiency. Disorders of eye movement and hearing appear only to occur in association with KS. Taken together, these findings indicate a clear phenotypic separation between KS and nIHH. However, pedigree studies suggest that autosomal KS is an heterogeneous condition, with incomplete phenotypic penetrance within pedigrees, and that some cases of autosomal KS, nIHH and even isolated anosmia are likely to have a common genetic basis. The prevalences of anosmia, mirror movements and unilateral renal agenesis among X-KS men are estimated to be 100, 85 and 31%, respectively. In sporadic IHH, mirror movements and unilateral renal agenesis are 100% specific phenotypic markers of de novo X-KS. By comparison, only 7/10 X-KS families harboured KAL coding defects. Clinical ascertainment, using mirror movements, renal agenesis and ichthyosis as X-KS-specific phenotypic markers, suggested that de novo X-KS was unlikely to comprise more than 11% of sporadic cases. The majority of sporadic KS cases are therefore presumed to have an autosomal basis and, hence, the preponderance of affected KS males over females remains unexplained, though reduced penetrance in women would be a possibility.


Subject(s)
Extracellular Matrix Proteins , Gonadotropins/deficiency , Hypogonadism/genetics , Adolescent , Adult , Craniofacial Abnormalities/genetics , Dyskinesias/genetics , Female , Genetic Linkage , Gonadotropins/genetics , Humans , Kallmann Syndrome/genetics , Kidney/abnormalities , Male , Nerve Tissue Proteins/genetics , Olfaction Disorders/genetics , Pedigree , Phenotype , Prospective Studies , Retrospective Studies , X Chromosome
15.
Arch Dis Child ; 85(1): 60-1, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11420205

ABSTRACT

Over the 10 year period 1987-1996, 328 children with type 1 diabetes mellitus presented in the city of Birmingham, England, of whom 27% had diabetic ketoacidosis. Asian children under the age of 5 had an eightfold increased risk of presenting in diabetic ketoacidosis compared with non-Asian children of the same age.


Subject(s)
Diabetes Mellitus, Type 1/ethnology , Diabetic Ketoacidosis/ethnology , Adolescent , Age Factors , Asia/ethnology , Child , Child, Preschool , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/diagnosis , Diabetic Ketoacidosis/diagnosis , Diabetic Ketoacidosis/etiology , England/epidemiology , Female , Humans , Infant , Infant, Newborn , Male , Referral and Consultation , Risk Factors
16.
Arch Dis Child ; 84(6): 512-3, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11369572

ABSTRACT

Three infants with subphrenic abscess, pyonephrosis, and obstructive ureterocoele respectively had grossly increased concentrations of plasma ammonia. This was considered to be a result of infections with urea splitting organisms. All died in spite of intensive care support, including specific measures to reduce plasma ammonia.


Subject(s)
Hyperammonemia/microbiology , Sepsis/complications , Ammonia/metabolism , Critical Care , Critical Illness , Fatal Outcome , Female , Humans , Hyperammonemia/therapy , Hypoxia-Ischemia, Brain/microbiology , Infant , Infant, Newborn , Male , Sepsis/therapy
17.
Arch Dis Child ; 84(5): 440-3, 2001 May.
Article in English | MEDLINE | ID: mdl-11316696

ABSTRACT

BACKGROUND: Growth hormone (GH) has been used to promote growth in both the short and long term in a number of dysmorphic syndromes, including Turner syndrome. As this condition shares many clinical features with Noonan syndrome, it would seem logical to treat the latter group with GH. AIMS: To assess the short and long term response to GH therapy in patients with Noonan syndrome. METHODS: Analysis of patients with Noonan syndrome in the Pharmacia & Upjohn International Growth Study (this post-marketing database contains data on the majority of patients currently treated with GH in the UK). A questionnaire was also sent to participating clinicians. RESULTS: Data on 66 patients (54 males) were available for study. At the start of GH therapy children were short, compared with both normal and Noonan children. During the first year of GH therapy height velocity increased from a mean of 4.9 to 7.2 cm per year. For patients treated long term with GH, mean height SDS increased from -2.9 pretreatment to -2.6 after one year and -2.3 after five years. Of the 10 patients at near final height, only one had a height above the 3rd centile for normal adults and above the mean for untreated Noonan patients. The mean increment in final height was 3.1 cm (range -1.1 to 6.5 cm). CONCLUSIONS: GH therapy in patients with Noonan syndrome will improve height velocity in the short term. Longer-term therapy results in a waning of effect; initial indications are that final height is not improved substantially in most patients.


Subject(s)
Growth Disorders/etiology , Growth Hormone/therapeutic use , Noonan Syndrome/complications , Adolescent , Body Height/drug effects , Child , Female , Follow-Up Studies , Growth Disorders/drug therapy , Humans , Long-Term Care , Male , Treatment Outcome
18.
Arch Dis Child ; 82(5): 425-7, 2000 May.
Article in English | MEDLINE | ID: mdl-10799440

ABSTRACT

BACKGROUND: Sweat testing procedures are perceived to vary widely. AIM: To evaluate variability in sweat collection, analysis, and interpretation. METHODS: Questionnaire responses from 30 self selected centres: 15 paediatric centres, and 15 district general hospitals. RESULTS: Centres carried out 30-400 tests per year (median 100), with a diagnostic rate of 1:5-152 (median 1:30). Staff performed 5-268 tests per year. Minimum test age varied from 24 hours to four months. All stimulated sweating by pilocarpine iontophoresis using varying currents and times. Twenty six had observed urticaria or skin reddening, and nine blistering or burns. Sweat was collected for 10-60 minutes onto filter paper or into Macroduct coils. Between 2% and 25% of tests were considered insufficient. Twenty eight measured sodium, 24 chloride, and one osmolality and conductivity. Fifteen used literature and five in house reference ranges. Eleven would not test severely eczematous children. CONCLUSIONS: Local audit is required to improve performance, as well as a national guideline to standardise collection, and external quality assessment to provide analytical feedback.


Subject(s)
Clinical Laboratory Techniques/standards , Cystic Fibrosis/diagnosis , Laboratories, Hospital/standards , Sweat/chemistry , Age Factors , Clinical Laboratory Techniques/statistics & numerical data , Humans , Infant , Infant, Newborn , Laboratories, Hospital/statistics & numerical data , Reference Values , United Kingdom
19.
J Environ Sci Health B ; 35(1): 103-20, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10693058

ABSTRACT

The objective of this study was to determine the effects of varying nitrogen sources and concentrations upon glutamine synthetase and protease activities in Prevotella ruminicola strain B(1)4. Based on growth response it appears that ammonium chloride or pepticase limited P. ruminicola becomes nitrogen limited when nitrogen concentration is at 0.5 mM. However, when casein was provided as the sole source of nitrogen P. ruminicola becomes nitrogen limited at 2.5 mM. Glutamine synthetase activity was measured from mid-log phase cells grown in either nitrogen-limited or non-limited conditions. No activity was detectable in the non-limited treatments. However, in the N-limited treatments, pepticase had the highest activity (20.76 units), followed by ammonium chloride (18.72 units) and casein (14.42 units). Protease activity assays indicated that nitrogen-limited cultures had higher proteolytic activity than non-limited cultures. Moreover, these activities appeared to follow the same response pattern as the previously observed glutamine synthetase activities. The results of this study indicate that P. ruminicola strain B(1)4 protease activity may be influenced by nitrogen concentration such that activity increases when nitrogen availability decreases.


Subject(s)
Endopeptidases/analysis , Glutamate-Ammonia Ligase/analysis , Nitrogen/chemistry , Prevotella/enzymology , Prevotella/growth & development , Rumen/microbiology , Animals
20.
J Stud Alcohol ; 61(1): 64-71, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10627098

ABSTRACT

OBJECTIVE: Alcohol-dependent individuals frequently report increased desire for alcohol and exhibit increased alcohol-seeking behaviors following a single drink. The phenomenon, known as priming, has been demonstrated in the laboratory in alcohol-dependent humans and in nonhumans, but the effect is inconsistently observed in nonproblem social drinkers. The current experiment examined this effect in healthy, nonproblem social drinkers across a range of preload doses. METHOD: Using a repeated-measures design, 12 social drinkers were given ethanol (0.2, 0.4 or 0.8 g/kg) or placebo preloads. Various subjective effects measures were obtained at regular intervals. In addition, before and after consuming, the preload subjects performed an operant task on which they made repeated choices for either ethanol or money. RESULTS: Ethanol dose-dependently increased subjective reports of drug liking and desire to take more ethanol. When data from all subjects were examined, ethanol did not affect choices for ethanol on the choice task. However, in subjects who reported the greatest positive mood effects from ethanol (0.8 g/kg), the ethanol preload increased choices for ethanol over money on the choice task. CONCLUSIONS: These findings provide evidence for a priming effect of ethanol in social drinkers as measured by increased subjective desire for drug. The findings also suggest that the priming effects may be strongest in individuals who experience the greatest subjective positive mood effects from ethanol.


Subject(s)
Affect/drug effects , Alcohol Drinking/psychology , Central Nervous System Depressants/pharmacology , Conditioning, Operant/drug effects , Ethanol/pharmacology , Adult , Alcohol Drinking/physiopathology , Analysis of Variance , Central Nervous System Depressants/administration & dosage , Choice Behavior/drug effects , Ethanol/administration & dosage , Female , Humans , Male , Psychomotor Performance/drug effects , Surveys and Questionnaires
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