Impact of diseases of the hard tissues of teeth on oral health-related quality of life of schoolchildren in area with a high concentration of fluoride in drinking water

OBJECTIVE

To assess the impact of caries, Molar Incisor Hypomineralization (MIH), and fluorosis on the Oral Health-Related Quality of Life (OHRQoL) of schoolchildren aged 8-10 years living in area with different fluoride levels in the drinking water.

SUBJECT AND METHODS

The prevalence of caries and fluorosis were assessed among 663 Mexican schoolchildren using the International Caries Detection and Assessment System (ICDAS II) and the Thylstrup and Fejerskov Index (TFI), respectively. MIH was recorded using the European Academy of Pediatric Dentistry (EAPD) criteria and OHRQoL using the Child Perceptions Questionnaire (CPQ8-10). Poisson regression models were used in data analysis.

RESULTS

Schoolchildren presenting two of the three conditions (cavitated lesions and TFI≥4, cavitated lesions and MIH or TFI≥4 and MIH) experienced worse quality of life than children who did not [RR=4.18; (95% CI 3.83, 4.56)]. Children with all three conditions had worse quality of life than children who did not [RR=5.64; (95% CI 5.13, 6.20)].

CONCLUSIONS

Fluorosis, MIH, and caries have a negative impact on the OHRQoL of schoolchildren living in area with a high concentration of fluoride in their drinking water.

Contingency management for smoking cessation among individuals with substance use disorders: In-treatment and post-treatment effects

INTRODUCTION

Smokers with substance use disorders (SUDs) show elevated tobacco prevalence, and smoking abstinence rates are considerably low. This randomized controlled trial sought to compare the effect of a cognitive behavioral treatment (CBT) that includes an episodic future thinking (EFT) component with the same treatment protocol plus contingency management (CM). This study aims to examine the effect of CM on smoking outcomes and in-treatment behaviors (i.e., retention, session attendance and adherence to nicotine use reduction guidelines), and to analyze whether these in-treatment variables predicted days of continuous abstinence at end-of-treatment.

METHOD

A total of 54 treatment-seeking participants (75.9% males, M = 46.19 years old) were allocated to CBT + EFT (n = 30) or CBT + EFT + CM (n = 24). Intervention consisted of eight weeks of group-based sessions. Tobacco abstinence was verified biochemically by testing levels of carbon monoxide (≤4ppm) and urine cotinine (≤80 ng/ml).

RESULTS

CM intervention increased 24-hour tobacco abstinence (50% vs. 20%, χ²(1) = 5.4; p = .021) and days of continuous abstinence (M = 5.92 ± 7.67 vs. 5.53 ± 12.42; t(52) = -0.132; p = 0.89) at end-of-treatment in comparison with CBT + EFT intervention. Although not statistically significant, CBT + EFT + CM enhanced in-treatment behaviors, in terms of retention (83.3% vs. 70%; χ²(1) = 0.255; p = .208), sessions attended (12.29 ± 3.22 vs. 10.93 ± 3.26; t(52) = -1.527; p = .133) and adherence to weekly nicotine use reduction targets (41.07% ± 31.96 vs. 35% ±2 6.28; t(52) = -0.766; p = .447). A higher percentage of samples meeting reduction guidelines (β = 0.609; p<.001) predicted days of continuous abstinence at end-of-treatment.

CONCLUSION

Combining CM with CBT + EFT improves short-term quitting rates. Findings suggest the need to incorporate strategies for improving adherence to nicotine reduction guidelines.

Discovery of a Major QTL Controlling Trichome IV Density in Tomato Using K-Seq Genotyping

Trichomes are a common morphological defense against pests, in particular, type IV glandular trichomes have been associated with resistance against different invertebrates. Cultivated tomatoes usually lack or have a very low density of type IV trichomes. Therefore, for sustainable management of this crop, breeding programs could incorporate some natural defense mechanisms, such as those afforded by trichomes, present in certain Solanum species. We have identified a S. pimpinellifolium accession with very high density of this type of trichomes. This accession was crossed with a S. lycopersicum var. cerasiforme and a S. lycopersicum var. lycopersicum accessions, and the two resulting F2 populations have been characterized and genotyped using a new genotyping methodology, K-seq. We have been able to build an ultra-dense genetic map with 147,326 SNP markers with an average distance between markers of 0.2 cm that has allowed us to perform a detailed mapping. We have used two different families and two different approaches, QTL mapping and QTL-seq, to identify several QTLs implicated in the control of trichome type IV developed in this accession on the chromosomes 5, 6, 9 and 11. The QTL located on chromosome 9 is a major QTL that has not been previously reported in S. pimpinellifolium. This QTL could be easily introgressed in cultivated tomato due to the close genetic relationship between both species.

Ploidy Modification for Plant Breeding Using In Vitro Organogenesis: A Case in Eggplant

The use of antimitotic agents such as colchicine has been common to obtain polyploid organisms. However, this approach entails certain problems, from its toxicity to the operators for being carcinogenic compounds to the instability of the individuals obtained, and the consequent reversion to its original ploidy because the individuals obtained in most cases are chimeric. In vitro culture allows taking advantage of the full potential offered by the cellular totipotence of plant organisms. Based on this, we present a new in vitro culture protocol to obtain polyploid organisms using zeatin riboside (ZR) and eggplant as a model organism. Flow cytometry is used to identify tetraploid regenerants. The regeneration of whole plants from the appropriate tissues using ZR allowed developing polyploid individuals in eggplant, a crop that tends to be recalcitrant to in vitro organogenesis. Thanks to the use of the polysomatic pattern of the explants, we have been able to develop a methodology that allows to obtain stable non-chimeric polyploid individuals from organogenic processes.

A Deep Learning-Based System (Microscan) for the Identification of Pollen Development Stages and Its Application to Obtaining Doubled Haploid Lines in Eggplant

The development of double haploids (DHs) is a straightforward path for obtaining pure lines but has multiple bottlenecks. Among them is the determination of the optimal stage of pollen induction for androgenesis. In this work, we developed Microscan, a deep learning-based system for the detection and recognition of the stages of pollen development. In a first experiment, the algorithm was developed adapting the RetinaNet predictive model using microspores of different eggplant accessions as samples. A mean average precision of 86.30% was obtained. In a second experiment, the anther range to be cultivated in vitro was determined in three eggplant genotypes by applying the Microscan system. Subsequently, they were cultivated following two different androgenesis protocols (Cb and E6). The response was only observed in the anther size range predicted by Microscan, obtaining the best results with the E6 protocol. The plants obtained were characterized by flow cytometry and with the Single Primer Enrichment Technology high-throughput genotyping platform, obtaining a high rate of confirmed haploid and double haploid plants. Microscan has been revealed as a tool for the high-throughput efficient analysis of microspore samples, as it has been exemplified in eggplant by providing an increase in the yield of DHs production.

Marginalization and fluorosis its relationship with dental caries in rural children in Mexico: A cross-sectional study

OBJECTIVE

Examine the association between marginalization and fluorosis with caries experience in Mexican rural children aged 8-12, in Oaxaca, Mexico.

METHODS

Cross-sectional study of 283 rural schoolchildren selected from two locations with high and medium levels of marginalization where the water fluoride concentration ranged from 2.0 to 2.5 ppm/F. Caries was evaluated using the DMFT index and dental fluorosis with the Thylstrup-Fejerskov Index (TFI). Socioeconomic data were collected from participants' parents, with data on the children's characteristics collected from them via a questionnaire.

RESULTS

The prevalence of caries was 72.4% (DMFT ≥1) in the permanent dentition. The prevalence of fluorosis was 98.0% (TFI ≥4=71.4%). 54.8% of the children brushed their teeth two or more times daily. In logistic regression children living in high levels of marginalization were more likely to present caries (OR=2.11, 95% CI 1.13 - 3.93) than children living in medium levels. Children with severe fluorosis (TFI ≥4) (OR=1.93, 95% CI 1.06 - 3.53) were more likely have caries than those with TFI ⟨3.

CONCLUSION

Rural children with a high level of marginalization and fluorosis (TFI ≥4) were more likely to present caries. Poor oral hygiene and low dental service levels were found in both marginalized areas. Populations with medium/high marginalization are more susceptible to caries.

A highly efficient organogenesis protocol based on zeatin riboside for in vitro regeneration of eggplant

BACKGROUND

Efficient organogenesis induction in eggplant (Solanum melongena L.) is required for multiple in vitro culture applications. In this work, we aimed at developing a universal protocol for efficient in vitro regeneration of eggplant mainly based on the use of zeatin riboside (ZR). We evaluated the effect of seven combinations of ZR with indoleacetic acid (IAA) for organogenic regeneration in five genetically diverse S. melongena and one S. insanum L. accessions using two photoperiod conditions. In addition, the effect of six different concentrations of indolebutyric acid (IBA) in order to promote rooting was assessed to facilitate subsequent acclimatization of plants. The ploidy level of regenerated plants was studied.

RESULTS

In a first experiment with accessions MEL1 and MEL3, significant (p < 0.05) differences were observed for the four factors evaluated for organogenesis from cotyledon, hypocotyl and leaf explants, with the best results obtained (9 and 11 shoots for MEL1 and MEL3, respectively) using cotyledon tissue, 16 h light / 8 h dark photoperiod conditions, and medium E6 (2 mg/L of ZR and 0 mg/L of IAA). The best combination of conditions was tested in the other four accessions and confirmed its high regeneration efficiency per explant when using both cotyledon and hypocotyl tissues. The best rooting media was R2 (1 mg/L IBA). The analysis of ploidy level revealed that between 25 and 50% of the regenerated plantlets were tetraploid.

CONCLUSIONS

An efficient protocol for organogenesis of both cultivated and wild accessions of eggplant, based on the use of ZR, is proposed. The universal protocol developed may be useful for fostering in vitro culture applications in eggplant requiring regeneration of plants and, in addition, allows developing tetraploid plants without the need of antimitotic chemicals.

Human acute promyelocytic leukemia NB4 cells are sensitive to esculetin through induction of an apoptotic mechanism

Acute promyelocytic leukemia (APL) is a type of cancer, in which immature cells called promyelocytes proliferate abnormally. Human NB4 cell line appears to be a suitable in vitro model to express the characteristics of APL. In this work, we have investigated the effects of esculetin, a coumarin derivative with antioxidant properties, on the viability, the induction of apoptosis and the expression of apoptotic factors in NB4 cells. Cells treated with esculetin at several concentrations (20-500 μM) and for different times (5-24 h) showed a concentration- and time-dependent viability decrease with increased subdiploid DNA production. Esculetin inhibited cell cycle progression and induced DNA fragmentation. Moreover, annexin-V-FITC cytometry assays suggested that increased toxicity is due to both early and late apoptosis. This apoptosis process is be mediated by activation of caspase-3 and caspase-9. Treatments with progressively increasing concentrations (from 100 μM to 500 μM) of esculetin produced a reduction of Bcl2/Bax ratio in NB4 cells at 19 h, without affecting p53 levels. Proapoptotic action of esculetin involves the ERK MAP kinase cascade since increased levels of phosphorylated ERK were observed after those treatments. Increments in the levels of phosphorylated-Akt were also observed. Additionally, esculetin induced the loss of mitochondrial membrane potential with a release of cytochrome c into the cytosol which starts at 6 h of treatment with esculetin and increases up to 24 h. Esculetin induced an increase in superoxide anion at long times of treatment and a reduction of peroxides at short times (1 h) with an observed increase at 2-4 h of treatment. No significant changes in NO production was observed. Esculetin reduced the GSH levels in a time-dependent manner. In summary, the present work shows the cytotoxic action of esculetin as an efficient tool to study apoptosis mechanism induction on NB4 cell line used as a relevant model of APL disease.

Mapping radon-prone areas using γ-radiation dose rate and geological information

Identifying radon-prone areas is key to policies on the control of this environmental carcinogen. In the current paper, we present the methodology followed to delineate radon-prone areas in Spain. It combines information from indoor radon measurements with γ-radiation and geological maps. The advantage of the proposed approach is that it lessens the requirement for a high density of measurements by making use of commonly available information. It can be applied for an initial definition of radon-prone areas in countries committed to introducing a national radon policy or to improving existing radon maps in low population regions.

Levetiracetam as an alternative therapy for Tourette syndrome

Tourette syndrome is a common childhood-onset neuropsychiatric disorder characterized by chronic tics and frequent comorbid conditions such as attention deficit disorder. Most currently used tic-suppressing drugs are frequently associated with serious adverse events. Thus, alternative therapeutic agents with more favorable side-effect profiles are being evaluated. New hypotheses and recent studies involving GABAergic system in the pathophysiology of Tourette syndrome suppose a reason for the evaluation of GABAergic drugs. Levetiracetam is a drug with an atypical GABAergic mechanism of action that might be expected to improve tics. Although trials performed to evaluate the efficacy of levetiracetam in the treatment of Tourette syndrome have provided conflicting results, it may be useful in some patients. The established safe profile of levetiracetam makes this drug an alternative for treatment if intolerance to currently used drugs appears, but additional evaluation with larger and longer duration controlled studies are necessary to assess the real efficacy in patients with Tourette syndrome.

[Carpal tunnel syndrome in childhood.]

Introduction. Carpal tunnel syndrome (CTS) has usually a different clinical presentation in children compared to adults. On top of this, its rarity in childhood makes it difficult to diagnose. It has also different etiologies at this age, the majority of cases occur in children with lysosomal storage diseases (mucopolysaccharidosis and mucolipidosis) which may be the first manifestation of this disease in some cases. Clinical case. In this article we describe 3 cases of children aged between 4 and 10 years, 2 with idiopathic CTS and 1 with primary familial origin. The symptoms of the former were intermittent paresthesias and handling difficulty, while the familial case presented with a more typical paresthesias and pain. The neurophysiological study confirmed the diagnosis. Concerning the patient with a history of CTS in the family, MRI showed a compression of the nerve due to the thickening of the flexor retinaculum. In all cases, lysosomal storage disease was ruled out and a conservative treatment was initiated. Evolution was favorable in the idiopathic cases, one of them with an almost complete remission of symptoms, while the patient with a familial CTS follows a progressive course and is waiting for the surgical assessment. Discussion. The CTS in pediatric age presents milder and more unspecific symptoms than in adults, and the results of the exploration and provocation tests are often unclear. Surgical treatment is almost always necessary, although some idiopathic cases, particularly if they are not associated to the thickening of the flexor retinaculum, may improve with a conservative treatment.

[Coding in neuropediatrics based on the International Classification Diseases, 9th revision (ICD-9), 5th edition (2006)]

AIMS

To analyze International Classification Diseases, 9th revision (ICD-9) coding and adapt it, on a consensus basis, to 'reasons for medical consultation', 'diagnoses' and 'procedures' in child neurology.

MATERIALS AND METHODS

The most frequent reasons for medical consultation, diagnoses and procedures in neuropediatrics were selected and assigned the most appropriate ICD-9, Clinical Modification (5th ed.) (ICD-9-CM) codes in accordance with this system's coding rules. Disorders were grouped by sections, and allocated to the various members of the working group (13 child neurologists from 10 hospitals in Madrid and environs).

RESULTS

Available on the web www.neurologia.com/cie-9. ICD-9-CM codes were assigned to: 158 reasons for medical consultation; 886 diagnoses; 73 diagnostic procedures; and 53 therapeutic procedures. In every case, the most appropriate ICD-9 code was sought for the respective diagnosis. No codes were invented but the working group did take certain liberties with interpretation, which nevertheless showed respect for general ICD-9-CM philosophy and are described in full in the text.

CONCLUSIONS

The creation of this ICD-9 adaptation will not only enhance diagnostic coding in child neurology departments, but will also provide them with a useful tool for setting up databases to enable information to be retrospectively analyzed and shared by the different health centers.

[The clinical semiology of attention deficit hyperactivity disorder according to age, and the effectiveness of treatments at different ages]

INTRODUCTION

Attention deficit hyperactivity disorder (ADHD) is the most important cause of poor academic performance and is also usually associated with behavioural, emotional and sociability disorders.

AIM

To analyse the different clinical features and the response to psychostimulant therapy, according to the age.

SUBJECTS AND METHODS

We reviewed the cases of 152 children referred to Neuropaediatrics owing to suspected ADHD over a 6-year period. Diagnosis and comorbidity were investigated by the looking at their case history, by examination and observation, as well as by interviewing the parents (DSM-IV criteria), and by applying Conners' Rating Scale for parents and teachers, in addition to neuropsychological tests. In order to improve data processing, we established four groups according to the patient's age at diagnosis and when treatment was started: G1: 3-5; G2: 6-8; G3: 9-11; and G4: 12-15 years.

RESULTS

ADHD was diagnosed in 102 of the 152 children; 53% had the combined type, 26% were of the inattentional type, and 20% were hyperactive/impulsive. Poor school performance increased with age and reached 75% in G4. The same occurred with conduct disorders: at 6 years of age, 23% were found to have oppositional defiant disorder, and from the age of 9 onwards over 60% of them had conduct disorders. Up until 12 years of age they showed some improvement with psychostimulants and later the rate of dropouts from medical clinical controls and from treatment was over 40%.

CONCLUSIONS

The older patients are and the later ADHD is attended, the more problems they have. If successful preventive measures are to be implemented, it would be advisable to begin treatment even before children start primary education (5 years old), so as to try and avoid the pedagogical and behavioural repercussions observed in these children at the age of 6.

[Clinical progress of neonatal non-ketotic hyperglycinemia under treatment]

INTRODUCTION

Non-ketotic hyperglycinemia is a congenital error in the breakdown of glycine. The most common type is the classical neonatal form, which begins at the age of a few days with symptoms of lethargy, hypotonia, myoclonia, convulsions, apneas and, frequently, ends in death. Survivors usually develop intractable epilepsy and mental retardation. There is no effective treatment for this condition, but trials have been carried out with a therapy that diminishes the levels of glycine, benzoate (BZ), and another that blocks the excitatory effect in N-methyl-D-aspartate receptors: dextromethorphan (DTM).

CASE REPORT

We report on the progress of a classical neonatal case, which began at the age of a few hours with hypotonia and stupor, without myoclonias or seizures, but with a suppression wave trace on the electroencephalogram (EEG). Cerebrospinal fluid (CSF) showed glycine levels of 141 micromol/L (the normal level is 6.66 +/- 2.66 micromol/L), with a CSF/plasma ratio of 0.19 (the normal ratio is < 0.02). Treatment was started on the thirteenth day with BZ and DTM, and alertness and eye fixation improved in just three days; at the same time the EEG readings become normal. The glycine level in plasma returned to normal at two months and that in CSF was considerably reduced, although with CSF/plasma levels that were still high. At present the patient is 4 years old, has never had convulsions, EEG results have always been normal, and continues with BZ, DTM, carnitine and diet. The patient has presented a high degree of hypermotoric behaviour, but is currently more attentive and more sociable, has been walking from the age of 35 months and has a quotient in the different areas of development of 40-50.

CONCLUSIONS

The clinical progress made by our patient could be said to be anything but negligible, and we therefore recommend that treatment should be started as early as possible after diagnosis.

[Growth charts for the Spanish population with neurofibromatosis type 1]

OBJECTIVE

To make the charts of stature and head circumference of Spanish pediatric patients affected with neurofibromatosis type 1 (NF1), to compare them with the ones from a healthy population and to review the possible causes of its alterations.

PATIENTS AND METHODS

We obtained the data from 251 Spanish patients (122 women and 129 men) with NF1 seen in seven hospitals between the years 2000 and 2002, with ages between 1 month and 18 years old. The calculation of the 50th centile or median was done using the method of mobile variables, and the 3rd and 97th centiles where calculated from this median.

RESULTS

Girls with NF1 have a shorter stature than the healthy ones, which becomes evident after 10 years of age. We have not found differences in the stature between boys with the disease and those without it. In regards to head circumference, in boys and girls we have observed that it is bigger throughout life in patients affected with NF1, and that the 50th centile of healthy people correlates with the 3rd centile of those affected, the 97th centile of the healthy ones with the 50th centile of those affected, being the 3rd centile of the healthy people well below the 3rd centile of the affected ones, and the 97th centile of the affected ones well above the 97th of the healthy people.

CONCLUSIONS

The short stature in postpuberal girls and the macrocephaly in both sexes at all ages, are primary characteristics in the NF1 and they are not usually related with other alterations, although they are not specific for this illness.

Presence of granulocytic ehrlichia in ticks and serological evidence of human infection in La Rioja, Spain

In order to estimate the risks of human granulocytic ehrlichiosis (HGE) in an endemic area for Lyme disease in the North of Spain (La Rioja), we collected and investigated by PCR specific to the E. phagocytophila group DNA, a total of 6870 Ixodes ricinus ticks. We also used an indirect immunofluorescence (IFI) test to study the presence of antibodies to the HGE agent in 147 human serum samples including patients with Lyme disease (LD), forestry workers, and persons with history of previous tick bite. Fifty serum samples from healthy people resident in urban areas and with no history of tick-bite disorder and without tick exposure were used as controls. Four of 76 adults and 49 of 203 nymphs pools carried E. phagocytophila DNA. This result, and the finding of 1.4% of sera reacting in the IFI test confirms that this tick-borne agent is present in La Rioja, and that humans show evidence of contact with it. HGE should be considered in the differential diagnosis of flu-like syndromes in the study area in the north of Spain.

[Pseudotumor cerebri associated with maxillary sinusitis: clinico-pathological study]

INTRODUCTION

The pseudotumor cerebri is characterized by increased intracranial pressure in the absence of a space occupying lesions or obstruction to the circulation of cerebrospinal fluid (CSF). Increased pressure but normal composition of the CSF is the diagnostic criterion. Ear infections and other infections such as sinusitis have been cited as possible, but rare, causes.

CLINICAL CASE

A 12 year old girl presented with diplopia 10 days after starting treatment for sinusitis. On examination there was paresia of the VI cranial nerve to the left eye and marked bilateral papilledema. She had normal visual acuity with visual field measurements showing increased blind spot field in both eyes. Resonance studies only showed maxillary sinusitis. CSF pressure was 35 cm H2O, with 40 lymphomonocytes and normal biochemical findings. After 15 cm of CSF had been removed treatment was started with acetazolamide, dexamethasone and cefotaxime. A week later the diplopia had disappeared and the CSF pressure was 25, with no cells present. Two months later the visual fields and fundus oculi were normal. After follow-up for one year there was no recurrence.

CONCLUSIONS

We describe a case of pseudotumor cerebri associated with maxillary sinusitis. We do not know whether this is a chance association or whether there was a pathophysiological basis. The possibility should be considered so as to treat the cause or predisposing factor. The initial CSF pleocytosis would support the possibility of a relationship of the pseudotumor with an infectious condition (meningeal irritation or para-infectious pleocytosis meningeal irritation or para-infections pleocytosis in the context of an ENT infection), which might have precipitated the problem by interfering with the reabsorption of CSF.

[Non-dystonic torticollis. A report of a case secondary to retropharyngeal abscess]

INTRODUCTION

There are many causes of acquired non-dystonic torticollis: cervical bony anomalies, nasopharyngeal infections, tumours of the spinal cord, and posterior fossa, ocular, vestibular and gastrointestinal disorders. In children, non-dystonic is commoner than dystonic torticollis, except for in adverse reactions to drugs. Palatopharyngeal lesions due to a rigid object being impacted in the mouth (pencil-injury) are common in childhood. Many are not dangerous and require no specific treatment, although there is a risk of perforation of the pharyngeal wall and of a retropharyngeal abscess.

CLINICAL CASE

We report the case of a 9 year old boy who was seen in the Emergency Department complaining of fever present for four days and progressive cervical rigidity for the past two days which did not improve with myorelaxant drugs. A lateral X-ray of the spine showed prevertebral air and on the oesophagogram a fistula tract was seen. On further questioning the boy admitted that a stick he had had in his mouth had caused damage the day before his fever started. CT showed the extent of the abscess. After a week of treatment with antibiotics and corticosteroids the clinical features disappeared, and on CT after two weeks it was seen that the abscess had resolved.

CONCLUSIONS

We suggest that a lateral radiograph of the neck should be done in cases of acquired torticollis, even though there is no suspicious clinical history. Early diagnosis and treatment of retropharyngeal abscesses is essential to prevent extension to adjacent structures, and atlanto-axoid subluxation secondary to the oedema and tension of the ligaments caused by the abscess (Grisel's syndrome).

Functional consensus for mammalian osmotic response elements

The molecular mechanisms underlying adaptation to hyperosmotic stress through the accumulation of organic osmolytes are largely unknown. Yet, among organisms, this is an almost universal phenomenon. In mammals, the cells of the renal medulla are uniquely exposed to high and variable salt concentrations; in response, renal cells accumulate the osmolyte sorbitol through increased transcription of the aldose reductase (AR) gene. In cloning the rabbit AR gene, we found the first evidence of an osmotic response region in a eukaryotic gene. More recently, we functionally defined a minimal essential osmotic response element (ORE) having the sequence CGGAAAATCAC(C) (bp -1105 to -1094). In the present study, we systematically replaced each base with every other possible nucleotide and tested the resulting sequences individually in reporter gene constructs. Additionally, we categorized hyperosmotic response by electrophoretic mobility shift assays of a 17-bp sequence (-1108 to -1092) containing the native ORE as a probe against which the test constructs would compete for binding. In this manner, binding activity was assessed for the full range of osmotic responses obtained. Thus we have arrived at a functional consensus for the mammalian ORE, NGGAAAWDHMC(N). This finding should accelerate the discovery of genes previously unrecognized as being osmotically regulated.

ORE, a eukaryotic minimal essential osmotic response element. The aldose reductase gene in hyperosmotic stress

Organisms, almost universally, adapt to hyperosmotic stress through increased accumulation of organic osmolytes but the molecular mechanisms have only begun to be addressed. Among mammalian tissues, renal medullary cells are uniquely exposed to extreme hyperosmotic stress. Sorbitol, synthesized through aldose reductase, is a predominant osmolyte induced under hyperosmotic conditions in renal cells. Using a rabbit renal cell line, we originally demonstrated that hyperosmotic stress induces transcription of the aldose reductase gene. Recently, we cloned the rabbit aldose reductase gene, characterized its structure, and found the first evidence of an osmotic response region in a eukaryotic gene. Now, we have progressively subdivided this 3221-base pair (bp) region into discrete fragments in reporter gene constructs. Thereby, we have functionally defined the smallest sequence able to confer hyperosmotic response on a downstream gene independent of other putative cis-elements, that is, a minimal essential osmotic response element (ORE). The sequence of the ORE is CGGAAAATCAC(C) (bp -1105/-1094). A 17-bp fragment (-1108/-1092) containing the ORE used as a probe in electrophoretic mobility shift assays suggests hyperosmotic induction of a slowly migrating band. Isolation of trans-acting factor(s) and characterization of their interaction with the ORE should elucidate the basic mechanisms for regulation of gene expression by hyperosmotic stress.