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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 271 records · Page 15Linked to original sources

Thyrotoxicosis in a patient with submandibular thyroid.

Ectopic thyroid glands generally appear in the midline due to abnormal median migration; their presence lateral to the midline is rare. We report the case of a 42-year-old female who presented with symptoms of thyrotoxicosis and an expanding submandibular swelling. Tc-99m-sodium pertechnetate scanning showed thyroid tissue in the left submandibular region, while no thyroid tissue was seen in the normal site. The patient was treated with 10 mCi of 131I and subsequently became euthyroid. Literature review revealed seven cases of lateral aberrant thyroid tissue. The theories to explain lateral aberrant thyroid are presented.

Adult↗

Complexation ion-exchange chromatography of some metal ions on papers impregnated with Ti(IV)-based inorganic ion exchangers.

The chromatographic behavior of 40 metal ions is studied on titanium (IV) arsenate, titanium (IV) phosphate-, titanium (IV) molybdate-, titanium(IV) tungstate-, and titanium(IV) selenite-impregnated papers in 0.1M oxalic, citric, and tartaric acid as mobile phases. Similar studies are carried out on Whatman No. 1 papers for comparison. The ion-exchange capacity of these papers is determined, and their selectivity for different cations is discussed. The mechanism of migration is explained in terms of ion-exchange, precipitation, and adsorption. The prediction of elution sequence from RF values is also checked. The average Ri is found to be almost linearly dependent on the charge of the metal ions. The effect of the pKa of complexing acids on average RF values of 3d series metal ions is explained. A number of binary and ternary separations are achieved.

Cation Exchange Resins↗

Brown tumor of the sternum: a potential source of false-positive Tl-201 and Tc-99m subtraction imaging in the mediastinum.

Tl-201 and Tc-99m subtraction imaging is a well-established technique for detecting parathyroid adenomas. We report a case of a brown tumor of the upper sternum mimicking an ectopic mediastinal parathyroid adenoma on Tl-201 and Tc-99m subtraction imaging in a patient with hyperparathyroidism. This brown tumor showed Tl-201 uptake but not Tc-99m uptake and thus did not subtract out in this scan.

Adenoma↗

Dual thyroid ectopy: case report and review of the literature.

Dual ectopic thyroid glands rarely occur, and only six cases have been reported in the literature. The authors describe a 14-year-boy who had a midline neck swelling for 8 to 9 years. The swelling increased gradually, but he had no pressure symptoms. The thyroid hormone profile showed a moderately increased thyroid-stimulating hormone value and normal T3 and T4 levels. A Tc-99m sodium pertechnetate thyroid scan showed dual ectopic thyroid glands in the sublingual and subhyoid regions.

Adolescent↗

Nephroptosis: the Tc-99m glucoheptonate scan as a diagnostic method.

A 40-year-old man was examined because he was a potential "healthy" renal donor. However, the routine work-up before surgery revealed hypertension, although there was no family history of this condition. The patient was examined to exclude secondary causes of hypertension. Tc-99m glucoheptonate renal imaging showed nephroptosis of the right kidney when the patient was standing, and this may have been the cause of the hypertension.

Adult↗

Thyroid hemangioma: a case report with a review of the literature.

A 53-year-old man was found serendipitously to have increased blood-pool uptake in the right lobe of the thyroid during a radionuclide ventriculography study for left ventricular function. Primary thyroid hemangioma is a rare condition, with only two cases reported in the literature. Secondary hemangioma may occur as a result of fine-needle aspiration. This technique may cause hematoma formation, which generally resolves normally, but on rare occasions it can lead to cavernous hemangioma formation. In patients with a thyroid swelling who have a cold nodule on a thyroid scan and only blood on repeated fine-needle aspiration, Tc-99m erythrocyte blood-pool imaging may be performed to diagnose hemangioma.

Hemangioma↗

Assessing the need for reintubation: a prospective evaluation of unplanned endotracheal extubation.

OBJECTIVE: Unplanned endotracheal extubation (UEE) is a common complication in medical intensive care units but very little data about UEE in surgical populations are available. Our hypothesis is that the surgical intensive care unit (SICU) population requires reintubation less frequently compared with the medical intensive care unit population. We prospectively gathered data on patients in a SICU in an attempt to identify the incidence of UEE and to study the need for reintubation after UEE. METHODS: During an 18-month period, we prospectively identified SICU patients from a quality improvement database who required ventilatory support. All patients who self-extubated were included in the study. RESULTS: Fifty-eight of 1,178 intubated patients experienced unplanned extubation 61 times during the 18-month period. A total of 22 patients (36%) required reintubation, whereas 39 patients (64%) did not. Thirty-three patients self-extubated while being actively weaned from ventilatory support. Of these, only 5 patients (15%) required reintubation and 28 patients (85%) did not (p < 0.01). CONCLUSION: A total of 85% of patients who self-extubate during the weaning process did not require reintubation in our study. Those who have an FiO2 >50%, a lower PaO2/FiO2 ratio, had UEE occur by accident, or were not being weaned when UEE occurred required reintubation more frequently. These data suggest that some of our SICU patients are intubated longer than necessary, which may translate into more ventilator related complications, longer ICU stays and increased cost.

Adult↗

C-spine injury associated with gunshot wounds to the head: retrospective study and literature review.

OBJECTIVE: To determine the incidence of C-spine injury (CSI) associated with gunshot wounds (GSWs) to the head. METHODS: A retrospective chart review including patients with GSWs to the head and excluding those with penetrating facial/neck trauma was performed. Cervical clearance was by clinical/radiologic criteria in survivors, and autopsy in nonsurvivors. A MEDLINE literature search was performed and relevant articles reviewed. RESULTS: One hundred seventy-four charts were available for review; 90 had C-spine radiographs (complete series [49], lateral [33], and computed tomographic scan [8]). Of 84 with no radiographs, 29 were clinically cleared, and 55 died (32 cleared at autopsy). Twenty-three died without evaluation. None of the remaining 151 (87%) had CSI. Literature search yielded only three relevant articles. Combining the data from these articles yielded 534 patients, and CSI was excluded in 507 (95%). CONCLUSION: C-spine immobilization and diagnostic radiography are probably not necessary in patients with isolated GSWs to the head and may complicate and delay emergency airway management.

Cervical Vertebrae↗

ATMPK4, an Arabidopsis homolog of mitogen-activated protein kinase, is activated in vitro by AtMEK1 through threonine phosphorylation.

The modulation of mitogen-activated protein kinase (MAPK) activity regulates many intracellular signaling processes. In animal and yeast cells, MAP kinases are activated via phosphorylation by the dual-specificity kinase MEK (MAP kinase kinase). Several plant homologs of MEK and MAPK have been identified, but the biochemical events underlying the activation of plant MAPKs remain unknown. We describe the in vitro activation of an Arabidopsis homolog of MAP kinase, ATMPK4. ATMPK4 was phosphorylated in vitro by an Arabidopsis MEK homolog, AtMEK1. This phosphorylation occurred principally on threonine (Thr) residues and resulted in elevated ATMPK4 kinase activity. A second Arabidopsis MEK isoform, ATMAP2Kalpha, failed to phosphorylate ATMPK4 in vitro. Tyr dephosphorylation by the Arabidopsis Tyr-specific phosphatase AtPTP1 resulted in an almost complete loss of ATMPK4 activity. Immunoprecipitates of Arabidopsis extracts with anti-ATMPK4 antibodies displayed myelin basic protein kinase activity that was sensitive to treatment with AtPTP1. These results demonstrate that a plant MEK can phosphorylate and activate MAPK, and that Tyr phosphorylation is critical for the catalytic activity of MAPK in plants. Surprisingly, in contrast to the animal enzymes, AtMEK1 may not be a dual-specificity kinase but, rather, the required Tyr phosphorylation on ATMPK4 may result from autophosphorylation.

Arabidopsis↗

Interaction specificity of Arabidopsis calcineurin B-like calcium sensors and their target kinases.

Calcium is a critical component in a number of plant signal transduction pathways. A new family of calcium sensors called calcineurin B-like proteins (AtCBLs) have been recently identified from Arabidopsis. These calcium sensors have been shown to interact with a family of protein kinases (CIPKs). Here we report that each individual member of AtCBL family specifically interacts with a subset of CIPKs and present structural basis for the interaction and for the specificity underlying these interactions. Although the C-terminal region of CIPKs is responsible for interaction with AtCBLs, the N-terminal region of CIPKs is also involved in determining the specificity of such interaction. We have also shown that all three EF-hand motifs in AtCBL members are required for the interaction with CIPKs. Several AtCBL members failed to interact with any of the CIPKs presented in this study, suggesting that these AtCBL members either have other CIPKs as targets or they target distinct proteins other than CIPKs. These results may provide structural basis for the functional specificity of CBL family of calcium sensors and their targets.

Amino Acid Sequence↗

Elevated cardiac troponin levels do not predict adverse outcomes in hospitalized patients without clinical manifestations of acute coronary syndromes.

The prognostic significance of elevated cardiac troponin levels (CTL) in hospitalized patients with no other evidence of myocardial ischemia or injury is largely unknown. Fifty patients (mean age 61 +/- 15 years, 15 women) out of 580 consecutive hospitalized patients were selected based on normal CK-MB and at least 3-fold increase of CTL. The medical charts of these patients were reviewed and a 1-year follow-up was performed. The most frequent admission diagnoses were exacerbation of congestive heart failure (22%), stroke (20%) followed by respiratory failure (6%), cirrhosis (6%), gastrointestinal bleeding (6%), end-stage renal disease (4%), atrial fibrillation (4%) and metastatic malignancies (4%). Abnormal CTL prompted a cardiology consult in 48% of patients, an echocardiogram in 44%, myocardial perfusion study in 10% and coronary angiography in 1 patient. Of 21 deaths, only 1 was related to an acute coronary event. The measurement of CTL in patients without definite clinical or electrocardiographic evidence of myocardial ischemia and with a wide spectrum of clinical diagnoses does not predict in-hospital and at 1 year cardiovascular complications and/or cardiac death.

Acute Disease↗

Molecular genetics of septo-optic dysplasia.

Septo-optic dysplasia (SOD) is a highly variable condition characterized by midline neurological abnormalities associated with pituitary hypoplasia and optic nerve hypoplasia. The aetiology is unknown. Mutant mice, in which a novel homeobox gene, Hesx1, has been disrupted, exhibit a phenotype that resembles the phenotype of SOD. We therefore wished to explore the possibility that this gene is implicated in SOD. We cloned and sequenced the human homologue HESX1 and screened for mutations in affected individuals using single-stranded conformational polymorphism analysis, followed by cloning and sequencing of any exons which showed a band shift. Two siblings with SOD were homozygous for an Arg53Cys missense mutation within the HESX1 homeodomain, leading to a loss of in vitro DNA binding. Subsequently, we have identified heterozygous mutations in HESX1 that are associated with milder pituitary phenotypes. Our studies indicate a vital role for Hesx1/HESX1 in forebrain and pituitary development in mouse and man, and hence in some cases of SOD.

Animals↗

Dental health indices and caries associated microflora in children with unilateral cleft lip and palate.

OBJECTIVE: To investigate the dental health and caries related microflora of children with unilateral cleft lip and palate. STUDY GROUP: Sixty children with unilateral cleft lip and palate and matched controls. OUTCOME MEASURES: The decayed, missing, and filled teeth and surfaces in both the deciduous and permanent dentitions. The presence of developmental defects and plaque and gingivitis scores were also recorded. Plaque was collected from 25 of the children and their matched controls from three different sites, which were (1) the first approximal site distal to the cleft, (2) a contralateral anterior site, and (3) a remote site. It was cultured for Streptococcus mutans and lactobacilli. Plaque was collected from two sites in the matched controls. RESULTS: There was no significant difference in the caries, plaque, and gingivitis scores between the children with cleft palate and the controls. A greater number of enamel opacities were recorded in the control group, and there was a higher prevalence of enamel discoloration in the children with cleft lip and palate. There was no significant difference in the proportion of S. mutans or lactobacilli at the cleft site, compared with the unaffected site in the study group, although there was an anterior-posterior gradient in the proportion of S. mutans. There was no significant association between the stagnation area at the cleft site and the bacteria associated with dental caries.

Adolescent↗

Optically active arthropod repellents for use against disease vectors.

Optically inactive 1-[3-cyclohexen-1-ylcarbonyl] piperidine and 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine are repellents against blood-feeding arthropods. Pure stereoisomers of these compounds were synthesized and characterized for use in bioassays. Initial laboratory tests with the malaria vector Anopheles stephensi Liston showed that this species was repelled differentially by the stereoisomers of 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine. Two stereoisomers were twice as repellent as the other stereoisomers. These results indicate that stereoisomerism influences repellent efficacy in this class of compounds.

Animals↗