RESUMO
An unusual ß-amylase7 (BAM7) gene in some angiosperms, including grasses such as maize (Zea mays), appears to encode 2 functionally distinct proteins: a nuclear-localized transcription factor (BAM7) and a plastid-localized starch hydrolase (BAM2). In Arabidopsis (Arabidopsis thaliana), these 2 proteins are encoded by separate genes on different chromosomes but their physiological functions are not well established. Using the maize BAM7 gene as a model, we detected 2 populations of transcripts by 5'-RACE which encode the predicted proteins. The 2 transcripts are apparently synthesized independently using separate core promoters about 1 kb apart, the second of which is located in the first intron of the full-length gene. The N-terminus of the shorter protein, ZmBAM7-S, begins near the 3' end of the first intron of ZmBAM7-L and starts with a predicted chloroplast transit peptide. We previously showed that ZmBAM7-S is catalytically active with properties like those of AtBAM2. Here, we report that ZmBAM7-S targets green fluorescent protein to plastids. The transcript encoding the longer protein, ZmBAM7-L, encodes an additional DNA-binding domain containing a functional nuclear localization signal. This putative dual-function gene originated at least 400 Mya, prior to the emergence of ferns, and has persisted in some angiosperms that lack a separate BAM2 gene. It appears to have been duplicated and subfunctionalized in at least 4 lineages of land plants, resulting in 2 genes resembling Arabidopsis BAM2 and BAM7. Targeting of 2 products from a single gene to different subcellular locations is not uncommon in plants, but it is unusual when they are predicted to serve completely different functions in the 2 locations.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Magnoliopsida , Zea mays/genética , Zea mays/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Plastídeos/genética , Plastídeos/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Poaceae/metabolismo , Magnoliopsida/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismoRESUMO
BACKGROUND: The aim of this study was to determine mortality risk by calculating Score for Neonatal Acute Physiology and Perinatal Extension II (SNAP-PE-II) and Clinical Risk Index for Babies (CRIB) score, and evaluate prediction of the effects of antenatal corticosteroid and surfactant treatment on mortality. METHODS: This multicenter study was conducted simultaneously in five different centers in four different provinces in Southern Turkey between July 2012 and July 2013. A total of 1668 inborn subjects hospitalized in the neonatal intensive care unit within the first 12 h of delivery, and meeting the selection criteria, were included in the study, and CRIB and SNAP-PE-II were used to determine mortality. RESULTS: The SNAP-PE-II scoring system was applied to all patients, and the CRIB scoring system was used for 310 newborns with gestational age <32 weeks and weighing <1500 g. Of the 1668 patients, 188 died (mortality rate, 11.3%). Cut-off was found to vary with center, which changed specificity and sensitivity of the mortality scores. SNAP-PE-II significantly predicted mortality (P < 0.05) compared with CRIB. SNAP-PE-II also successfully predicted mortality in the group receiving antenatal corticosteroid compared with the group not receiving antenatal corticosteroid. CONCLUSION: SNAP-PE-II was a significant predictor of mortality in newborns with birthweight <1500 g compared with CRIB, and assessment of antenatal corticosteroid use in conjunction with SNAP-PE-II increased the accuracy of the prediction of mortality.
Assuntos
Anormalidades Congênitas/diagnóstico , Recém-Nascido de muito Baixo Peso , Unidades de Terapia Intensiva Neonatal , Medição de Risco/métodos , Peso ao Nascer , Anormalidades Congênitas/mortalidade , Feminino , Idade Gestacional , Humanos , Lactente , Mortalidade Infantil/tendências , Recém-Nascido , Masculino , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Turquia/epidemiologiaRESUMO
Use of tumor-suppressive microRNAs (miRNAs) as anti-cancer agents is hindered by the lack of effective delivery vehicles, entrapment of the miRNA within endocytic compartments, and rapid degradation of miRNA by nucleases. To address these issues, we developed a miRNA delivery strategy that includes (1) a targeting ligand, (2) an endosomal escape agent, nigericin and (3) a chemically modified miRNA. The delivery ligand, DUPA (2-[3-(1,3-dicarboxy propyl) ureido] pentanedioic acid), was selected based on its specificity for prostate-specific membrane antigen (PSMA), a receptor routinely upregulated in prostate cancer-one of the leading causes of cancer death among men. DUPA was conjugated to the tumor suppressive miRNA, miR-34a (DUPA-miR-34a) based on the ability of miR-34a to inhibit prostate cancer cell proliferation. To mediate endosomal escape, nigericin was incorporated into the complex, resulting in DUPA-nigericin-miR-34a. Both DUPA-miR-34a and DUPA-nigericin-miR-34a specifically bound to, and were taken up by, PSMA-expressing cells in vitro and in vivo. And while both DUPA-miR-34a and DUPA-nigericin-miR-34a downregulated miR-34a target genes, only DUPA-nigericin-miR-34a decreased cell proliferation in vitro and delayed tumor growth in vivo. Tumor growth was further reduced using a fully modified version of miR-34a that has significantly increased stability.
RESUMO
BACKGROUND: Necrotizing enterocolitis (NEC) is the most common gastrointestinal disease in neonatal intensive care units. Although the pathogenesis of NEC remains unclear, evidence suggests that infections, especially bacterial infections, may play an important role. Viral infections may also result in NEC. Several outbreaks of NEC associated with rotaviruses have been described previously. OBJECTIVE: To investigate the association between rotavirus (RV) and serum interleukin (IL)-6 and IL-8 levels in infants with NEC. METHODS: RV infections were prospectively studied using antigen detection in the stools of 31 infants with NEC. Additionally, serum levels of IL-6, IL-8 and tumour necrosis factor-alpha were tested using micro-ELISA at 0 h and 48 h after diagnosis of NEC. RESULTS: Fecal specimens from 13 infants were positive, while fecal specimens from 18 infants were negative for RV according to antigen detection (RV+ and RV- groups, respectively). The mortality rate and the severity of NEC were not significantly different between the RV+ and RV- groups. IL-6 levels at 0 h and 48 h after diagnosis of NEC in RV+ infants were lower compared with RV- infants, while IL-8 levels were greater at 0 h and 48 h after diagnosis of NEC in RV+ infants compared with RV- infants. CONCLUSION: A high prevalence of RV infection in neonates with NEC was found. Decreased IL-6 levels and increased IL-8 and tumour necrosis factor-alpha levels in RV+ neonates with NEC suggests a role for RV in NEC.
HISTORIQUE: L'entérocolite nécrosante (ECN) est la principale maladie gastro-intestinale observée dans les unités de soins intensifs néonatals. Même si la pathogenèse de l'ECN demeure nébuleuse, les données probantes indiquent que les infections, notamment les infections bactériennes, peuvent y jouer un rôle important. Les infections virales peuvent également provoquer une ECN. Plusieurs éclosions d'ECN associées à des rotavirus ont été décrites par le passé. OBJECTIF: Explorer l'association entre le rotavirus (RV) et les taux d'interleukine sérique (IL)-6 et IL-8 chez les nourrissons ayant une ECN. MÉTHODOLOGIE: Les chercheurs ont étudié les infections à RV de manière prospective au moyen de la détection des antigènes dans les selles de 31 nourrissons atteints d'une ECN. Ils ont également testé les taux sériques d'IL-6, d'IL-8 et de facteur de nécrose tumorale alpha au moyen du test micro-ELISA immédiatement après le diagnostic d'ECN, puis 48 heures plus tard. RÉSULTATS: Les échantillons fécaux de 13 nourrissons étaient positifs, tandis que ceux de 18 nourrissons étaient négatifs au RV d'après la détection des antigènes (groupe RV+ et groupe RV−, respectivement). Le taux de mortalité et la gravité de l'ECN ne différaient pas de manière significative entre le groupe RV+ et le groupe RV−. Les taux d'IL-6 immédiatement après le diagnostic d'ECN et 48 heures plus tard chez les nourrissons du groupe RV+ étaient inférieurs à ceux des nourrissons du groupe RV−, tandis que les taux d'IL-8 étaient plus élevés immédiatement après le diagnostic d'ECN et 48 heures plus tard chez les nourrissons du groupe RV+ que chez ceux du groupe RV−. CONCLUSION: Les chercheurs ont décelé une forte prévalence d'infection à RV chez les nouveau-nés ayant une ECN. Les taux d'IL-6 moins élevés et d'IL-8 et de facteur de nécrose tumorale alpha plus élevés chez les nouveau-nés du groupe RV+ ayant une ECN laissent supposer que le RV joue un rôle dans l'ECN.
RESUMO
In this study, we have prospectively recorded healthcare-associated infections (HAIs) in NICU and found incidence density as 18 infections per 1000 patient days. Of the infections, 51.3% was bacteriemia (BSI), and 45.1% was ventilator-associated pneumonia (VAP). Gram-negative microorganisms were predominant in VAP and Staphylococcus epidermidis was the leading microorganism (53.0% of BSIs) in BSIs. Multivariate logistic regression analysis showed the importance of hood O(2) use in days (RR: 1.3) and total parenteral nutrition use in days (RR: 1.09) for BSIs. Umbilical arterial catheterization in days (RR: 1.94), ventilator use in days (RR: 1.05), chest tube (RR: 12.55), orogastric feeding (RR: 3.32) and total parenteral nutrition in days (RR: 1.05) were found to be significantly associated with VAP. In conclusion, incidence density in our unit is high and Gram-negative rods are predominant similar to developing countries. These results strongly suggest improving measures of prevention and control of HAIs in the unit.
Assuntos
Infecção Hospitalar/epidemiologia , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/microbiologia , Infecção Hospitalar/microbiologia , Feminino , Humanos , Incidência , Recém-Nascido , Masculino , Pneumonia Associada à Ventilação Mecânica/epidemiologia , Pneumonia Associada à Ventilação Mecânica/microbiologia , Estudos Prospectivos , Fatores de Risco , Turquia/epidemiologiaRESUMO
Drug-induced dystonic reactions are a common presentation to the emergency department and typically occur with drugs like chlorpromazine, haloperidol and metoclopramide. There are no reports in the literature of dystonic reaction caused by albendazole. We report a case of albendazole-induced acute dystonic reaction whose symptoms completely resolved after the discontinuation of the drug. Even though dystonia side effects of albendazole are rare, it can induce an alarming dystonia in some sensitive children. The mechanism of dystonia is unclear.
Assuntos
Albendazol/efeitos adversos , Anti-Helmínticos/efeitos adversos , Distonia/induzido quimicamente , Doença Aguda , Criança , Humanos , MasculinoRESUMO
AIM: To report the incidence of healthcare-associated infections (HAIs), site of infection and bacterial epidemiology in the Neonatal Intensive Care Unit in a university hospital in Adana, Turkey, between 2001 and 2006. METHODS: During these years, HAIs were collected by an active surveillance system. RESULTS: Five hundred one of 2832 infants hospitalised more than 72 h had 1124 HAI. The HAI incidence and incidence density ranged between 14.1 and 29.7 infections/100 patients, and 10.9-17.3 infections/1000 patient days within the study period; 61.5% of HAIs were ventilator-associated infections; 26.2% were bloodstream infections; 3.5% were urinary tract infections; 3.5% were necrotising enterocolitis (Stages II and III) and 1.4% was meningitis. The most frequent pathogens were gram-negative pathogens (75.6% of all infections) followed by gram-positive micro-organisms (21.4%) and Candida species (3.0%). Birthweight, gestational age and Apgar scores were lower and overall mortality rate (32.9% vs. 19.7%) and number of inpatient days were higher in patients with HAIs (for all P<0.001) when compared with those who did not have HAIs. Furthermore, HAI rate was inversely related to birthweight (P<0.001). CONCLUSION: In this study, the overall infection rate is high compared with developed countries and predominant micro-organisms are gram-negative enteric rods. These results strongly suggest the need for improving measures for prevention and control of HAIs in this hospital.
Assuntos
Infecção Hospitalar/epidemiologia , Unidades de Terapia Intensiva Neonatal , Humanos , Recém-Nascido , Vigilância da População/métodos , Estudos Prospectivos , Turquia/epidemiologiaRESUMO
Homozygous protein C deficiency affects approximately 1/400,000 to 1/1,000,000 live births. Homozygous protein C deficiency is associated with catastrophic and fatal purpura fulminans-like or thrombotic complications and disseminated intravascular coagulation. In the present patient, genetic study revealed Arg178Trp, a mutation found widely in European population; but this is the first case of homozygous Arg178Trp mutation who suffered from catastrophic purpura fulminans phenotype.
Assuntos
Vasculite por IgA/etiologia , Mutação , Deficiência de Proteína C/genética , Sequência de Bases , Coagulação Intravascular Disseminada/etiologia , Feminino , Homozigoto , Humanos , Recém-Nascido , Dados de Sequência Molecular , Linhagem , Reação em Cadeia da Polimerase , Deficiência de Proteína C/complicações , Deficiência de Proteína C/fisiopatologiaRESUMO
INTRODUCTION: This is a prospective, observational study. The aims of the study were to determine the rate of bacteraemia in febrile children in Turkey, and to evaluate the usefulness of white blood cell (WBC) count and manual differential counts of peripheral blood smears and a RISK score in predicting bacteraemia among these children. MATERIALS AND METHODS: A total of 377 febrile children aged 3 to 36 months were included in the study. Complete blood cell (CBC) count, manual differential counts and blood cultures were performed in all patients. The main outcome measures used to evaluate the usefulness of the RISK score were sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), odds ratio (OR), posterior probability, areas under receiver operator characteristic curves (AUC) and miss-to-diagnosis ratio (MDR). RESULTS: Among the patients, 4.4% had bacteraemia and the predominant pathogen was Streptococcus pneumoniae. The Yale Observation Scale scores, percentages of neutrophil and bands, band-neutrophil ratio, absolute neutrophil count and absolute band count were found to be statistically significant predictors of bacteraemia. When the RISK score was 2 or higher, sensitivity was 93.8%, false positive ratio 35.8%, PPV 10.6%, NPV 99.5%, OR 26.2 (95% CI, 3.4 to 200.8), MDR 0.066 and posterior probability value 10%. CONCLUSIONS: We conclude that determination of the RISK score will significantly decrease unnecessary blood culture sampling, antibiotherapy and hospitalisation among febrile patients aged 3 to 36 months without an identifiable focus of infection.
Assuntos
Bacteriemia/diagnóstico , Febre/complicações , Bacteriemia/complicações , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Bactérias/isolamento & purificação , Criança , Pré-Escolar , Humanos , Lactente , Contagem de Leucócitos , Neutrófilos , Valor Preditivo dos Testes , Curva ROC , Medição de Risco , Sensibilidade e EspecificidadeRESUMO
This study was conducted in order to assess the normal range of subarachnoid space width in healthy term newborns. A total of 230 healthy newborns were evaluated within the first 28 days of life. Measurements were correlated with body weight, height and head circumference. Mean measurements for falx-cortex and craniocortical widths and the correlations are given in tables. Subarachnoid space widths increased as weight, height and head circumference increased and the correlation was statistically significant.
Assuntos
Espaço Subaracnóideo/anatomia & histologia , Espaço Subaracnóideo/diagnóstico por imagem , Estatura , Peso Corporal , Feminino , Idade Gestacional , Cabeça/anatomia & histologia , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos , Nascimento a Termo , UltrassonografiaRESUMO
Familial idiopathic scoliosis with conjugate gaze palsy is a rare autosomal recessive disorder characterized by progressive scoliosis and congenital absence of conjugate horizontal eye movement. In this article, two siblings who had scoliosis and conjugate gaze palsy are presented regarding clinical and laboratory findings.
Assuntos
Transtornos da Motilidade Ocular/etiologia , Transtornos da Motilidade Ocular/genética , Doenças do Nervo Oculomotor/etiologia , Doenças do Nervo Oculomotor/genética , Escoliose/complicações , Escoliose/genética , Adolescente , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: Transient tachypnea of neonate (TTN) and respiratory distress syndrome (RDS) of the newborn are the most common cause of early respiratory distress in the immediate neonatal period. There is increasing evidence to support the role for the activation of the renin angiotensin system during acute lung injury. OBJECTIVES: The purpose of this study was to determine if there is a relationship between angiotensin-converting enzyme (ACE) I/D polymorphism, ACE activity and TTN and respiratory distress syndromes. METHODS: Nineteen neonates with TTN, 20 neonates with RDS and 21 control infants are studied for ACE polymorphism and serum ACE activity. RESULTS: Twenty six (43.3%) patients have DD polymorphism, 19 (31.7%) patients have ID polymorphism and 15 (25%) patients have II polymorphism. Serum ACE activity is 43.5 ± 1.8 (40-46) U/L in DD, 31.5 ± 2.3 (28-36) U/L in ID and 22.1 ± 2.1(19-46) U/L in II patient. CONCLUSIONS: The study could not find any difference in DD alleles and ACE activity between control group and TTN group. ACE polymorphism was not different between RDS group and control group in this study.
Assuntos
Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Polimorfismo Genético , Síndrome do Desconforto Respiratório do Recém-Nascido/genética , Taquipneia Transitória do Recém-Nascido/genética , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Genótipo , Idade Gestacional , Humanos , Mutação INDEL/fisiologia , Recém-Nascido , Masculino , Polimorfismo Genético/fisiologia , Síndrome do Desconforto Respiratório do Recém-Nascido/complicações , Síndrome do Desconforto Respiratório do Recém-Nascido/metabolismo , Taquipneia Transitória do Recém-Nascido/complicações , Taquipneia Transitória do Recém-Nascido/metabolismoRESUMO
The staff in the neonatal intensive care units is required to have highly specialized training and the using equipment in this unit is so expensive. The random number of arrivals, the rejections or transfers due to lack of capacity and the random length of stays, make the advance knowledge of the optimal staff; equipment and materials requirement for levels of the unit behaves as a stochastic process. In this paper, the number of arrivals, the rejections or transfers due to lack of capacity and the random length of stays in a neonatal intensive care unit of a university hospital has been statistically analyzed. The arrival patients are classified according to the levels based on the required nurse: patient ratio and gestation age. Important knowledge such as arrivals, transfers, gender and length of stays are analyzed. Finally, distribution functions for patients' arrivals, rejections and length of stays are obtained for each level in the unit.
Assuntos
Nível de Saúde , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Terapia Intensiva Neonatal/estatística & dados numéricos , Interpretação Estatística de Dados , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Tempo de Internação , Masculino , Distribuição de Poisson , Distribuição por SexoRESUMO
OBJECTIVE: To report the inheritance of a pericentric inversion in chromosome 7 through the three progenies, congenital hydronephrosis, and recurrent miscarriages in an extended family. DESIGN: Case report. SETTING: Medical Faculty of Cukurova University in Turkey. PATIENT(S): Referred by obstetrics and gynecology clinic. INTERVENTION(S): Fetal urine and lymphocytic karyotype. MAIN OUTCOME MEASURE(S): Chromosomal analysis from fetal urine and peripheral blood lymphocytes were performed according to standard cytogenetic methods. RESULT(S): We assessed an extended family in which a large pericentric inversion in chromosome 7 is segregating; one of the three progenies with the karyotype 46,XY,inv(7)(p22;q22) was heterozygote for the inversion and presented with congenital hydronephrosis. His mother, mother's brother, grandfather, grandfather's brother, and his daughter were similar for the inversion. CONCLUSION(S): This case describes the further molecular characterization of these breakpoints on the short or long arm of chromosome 7(p22-q22). The inv(7) is also associated with fetal wastage and may be playing a role in the etiology of the family's miscarriages. These findings can be used in clinical genetics and may be an effective tool for reproductive guidance and genetic counseling.
Assuntos
Aborto Habitual/genética , Inversão Cromossômica , Cromossomos Humanos Par 7 , Hidronefrose/diagnóstico , Diagnóstico Pré-Natal/métodos , Adulto , Feminino , Hereditariedade , Humanos , Hidronefrose/diagnóstico por imagem , Hidronefrose/genética , Hidronefrose/patologia , Hidronefrose/urina , Recém-Nascido , Cariotipagem , Linfócitos/patologia , Masculino , Linhagem , Gravidez , Ultrassonografia , Urina/citologiaRESUMO
Rhabdomyolysis is a clinical picture which is rarely seen in children. In this case report here it is presented a patient who has biochemical and clinical signs of rhabdomyolysis and admitted to our clinic with hypernatremia. The authors think that it is necessary to be alert for rhabdomyolysis in severe hypernatremia cases.
Assuntos
Hipernatremia/complicações , Rabdomiólise/etiologia , Doença Aguda , Pré-Escolar , Feminino , Humanos , Hipernatremia/fisiopatologia , Insuficiência Renal/etiologia , Rabdomiólise/complicações , Índice de Gravidade de Doença , Síndrome , SedeRESUMO
A number of growth factors, their binding proteins, and their receptors have been shown to be induced in the hypoxic-ischemic (HI) brain. In this prospective study, we aimed at determining the levels of insulin-like growth factor 1 (IGF-1), growth hormone (GH), and cortisol in HI babies and at identifying whether they differ from the levels of control infants. The serum IGF-1 levels were measured after the first 12-24 h of life, and the measurements were repeated on the 5th and 10th days of life for babies with HI encephalopathy (n = 18) and on the 10th day of life for controls (n = 19). Blood samples for measurement of cortisol and GH from both HI and control groups were collected after the first 12-24 h of life. There were 11 babies in the mild-to-moderate (stages I and II) group and 7 babies in the severe (stage III) group according to Sarnat and Sarnat. The IGF-1 levels of the HI group measured after 12-24 h [78.5 +/- 27.9 (range 9-123.4) ng/ml] and on the 10th day [72.2 +/- 36.8 (range 29.7-159.2) ng/ml] of life were statistically significantly lower than the IGF-1 levels of the control group [121.5 +/- 50.4 (range 74.4-280.5) ng/ml and 133.1 +/- 34.4 (range 65.9-202) ng/ml, respectively] (p = 0.002 and p = 0.001, respectively). But there was no statistically significant difference between mild-to-moderate HI group and severe HI group in terms of IGF-1 levels after 12-24 h and 5 and 10 days of life (p > 0.05). Also there was no statistically significant difference in IGF-1 values after the first 12-24 h and after 10 days of life between HI subjects who died or survived (p > 0.05). The GH levels of the HI group after the first 12-24 h of life [34.6 +/- 32.3 (range 0.1-120) mIU/l] were statistically significantly higher than those in the control group [10.4 +/- 4.5 (range 3.7-16.9) mIU/l] (p = 0.005). There was no statistically significant difference in the serum cortisol levels between HI and control groups after the first 12-24 h of life [18.7 +/- 17.0 (range 1.6-65.1) microg/dl vs. 10.8 +/- 5.4 (range 3.0-23.2) microg/dl] (p > 0.05). No statistically significant correlation was found between IGF-1 levels and GH and cortisol levels of the HI encephalopathy group [r = -0.113 (p > 0.05) and r = 0.108 (p > 0.05), respectively]. In conclusion, this study showed decreased levels of serum IGF-1 and increased levels of GH which may be secondary to serum IGF-1 influx from the circulation to the brain as a protective mechanism or may be due to some cytokines which alter the GH/IGF axis, inhibit the action of IGF-1, and stimulate IGF-binding protein 1.
Assuntos
Hormônio do Crescimento Humano/sangue , Hipóxia-Isquemia Encefálica/sangue , Fator de Crescimento Insulin-Like I/análise , Glicemia/análise , Humanos , Hidrocortisona/sangue , Recém-Nascido , Estudos Prospectivos , Fatores de TempoRESUMO
Rhabdomyolysis is a clinical picture which is rarely seen in children. In this case report here it is presented a patient who has biochemical and clinical signs of rhabdomyolysis and admitted to our clinic with hypernatremia. The authors think that it is necessary to be alert for rhabdomyolysis in severe hypernatremia cases.