Measurement and modeling of phosphorous transport in shallow groundwater environments

Leaching of phosphorus (P) from agricultural soils, especially those that are sandy, is adversely impacting P-limited ecosystems like Florida's Everglades. A more developed understanding of P and water management strategies and their effects on P leaching is needed to achieve reductions in subsurface P losses, especially from intensively managed dual cropping systems under plastic mulch in shallow water regions. We compared the effects of conservation P and water management strategies with traditional practices on P transport to groundwater. A 3-year experiment was conducted on hydrologically isolated plots with plastic-mulched successive cropping systems to compare high (HEI) and soil test based recommended (REI) external input (water and fertilizer P) systems with traditional sub-irrigation (seepage), and REI with a potential water conservation subsurface drip irrigation system (REI-SD) with regard to groundwater P concentrations above and below the low conductivity spodic horizon (Bh). The REI treatments had higher available storage for rainfall and P than HEI. Use of both REI systems (REI=2098μg/L and REI-SD=2048μg/L) reduced groundwater P concentrations above the Bh horizon by 33% compared to HEI (3090μg/L), and results were significant at the 0.05 level. Although the subsurface drip system saved water, it did not offer any groundwater quality (P) benefit. Mixing and dilution of influent P below the low conductivity Bh horizon between treatments and with the regional groundwater system resulted in no significant differences in groundwater P concentration below the Bh horizon. Groundwater P concentrations from this study were higher than reported elsewhere due to low soil P storage capacity (SPSC), high hydraulic conductivity of sandy soils, and a high water table beneath crop beds. The HEI system leached more P due to ferilizer P in excess of SPSC and used higher irrigation volumes compared with REI systems. Despite a 40% difference in the average amount of added fertilizer P between HEI (187kg P2O5/ha) and REI (124kg P2O5/ha), soil Mehlich 1 P (M1P) values were similar for both systems while they received Pinput. Soil M1P for REI and REI-SD increased to a maximum of 55mg/kg while they received Pinput, and then gradually decreased after Pinput ceased. However, M1P for HEI increased steadily to a maximum of 145mg/kg by the end of the study with continued Pinput. Mehlich-1 P measured six years after the study still showed relatively high levels of P, a legacy effect of Pinput. The main factors influencing groundwater P concentration varied by seasons. During fall with frequent rainfall, the concentrations were influenced mainly by M1P and Pinput, and highlight a need for greater focus on Pinput management (vs. water management) during this season. However, during the dry period of spring, a greater focus on irrigation management is required since depth to water table and rainfall also become contributing factors. Three multivariate models (r(2)=0.67 to 0.93), for spring, fall, and annual periods, were developed for predicting groundwater P concentrations for a wide range of water and P inputs (0 to 191kg P2O5/ha of Pinput). The uniqueness of these models is that they use readily available hydrologic (rainfall and water table depth), management (Pinput), and soil (M1P) data commonly monitored by growers when managing water and nutrient inputs on agricultural landscapes. The development of similar models may not be necessary for other agro-ecosystems in similar regions since long-term data collected in these regions may be applied, with verification, to the models presented here.

A Type-II First Branchial Cleft Anomaly Presenting as a Post-Auricular Salivary Fistula: A Rare Presentation

First branchial cleft anomalies are rare with the average age of presentation as 19 years. There is an average delay of 3.5 years between initial presentation and adequate treatment due to diagnostic dilemma. A very rare variant of first branchial cleft anomaly presenting as a post-auricular salivary fistula is reported. A 12-year-old girl presented with a history of intermittent watery discharge, more so at the time of meals from a right post-auricular opening for last 3 years. Computed tomography sialography revealed a fistulous tract connecting the sub segmental duct of the parotid gland extending along the pre-tragus region in subcutaneous plane up to mastoid tip after passing inferior to external auditory canal. Superficial parotidectomy with identification of facial nerve branches was carried out for excision of the tract. Histopathology revealed sinus tract comprising of ectodermal components and acini of the parotid gland. We classified our case into work's type-2 based on anatomical location at an angle of mandible, its relationship to parotid gland and facial nerve and previous history of ear discharge. To the best of our knowledge, this is the first case of its type to be reported.

Pituitary tuberculoma

Tuberculosis of pituitary gland is rare. We report a case of tuberculosis of pituitary gland in a 68-year-old male presented with holocranial headache of four months duration with left temporal hemianopia, with visual acuity of 6/6, without any localizing sign. Magnetic resonance imaging showed a sellar ring enhancing mass with suprasellar extension. Patient was taken up for surgery and put on antitubercular treatment and hormone replacement therapy.

Association of the novel aminoglycoside resistance determinant RmtF with NDM carbapenemase in Enterobacteriaceae isolated in India and the UK

OBJECTIVES

16S rRNA methyltransferases are an emerging mechanism conferring high-level resistance to clinically relevant aminoglycosides and have been associated with important mechanisms such as NDM-1. We sought genes encoding these enzymes in isolates highly resistant (MIC >200 mg/L) to gentamicin and amikacin from an Indian hospital and we additionally screened for the novel RmtF enzyme in 132 UK isolates containing NDM.

METHODS

All highly aminoglycoside-resistant isolates were screened for armA and rmtA-E by PCR, with cloning experiments performed for isolates negative for these genes. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was used to determine the methylation target of the novel RmtF methyltransferase. RmtF-bearing strains were characterized further, including susceptibility testing, PFGE, electroporation, PCR-based replicon typing and multilocus sequence typing of rmtF-bearing plasmids.

RESULTS

High-level aminoglycoside resistance was detected in 140/1000 (14%) consecutive isolates of Enterobacteriaceae from India. ArmA, RmtB and RmtC were identified among 46%, 20% and 27% of these isolates, respectively. The novel rmtF gene was detected in 34 aminoglycoside-resistant isolates (overall prevalence 3.4%), most (59%) of which also possessed a bla(NDM) gene; rmtF was detected in 6 NDM producers from the UK. It was found on different plasmid backbones. Four and two isolates showed resistance to tigecycline and colistin, respectively.

CONCLUSIONS

RmtF was often found in association with NDM in members of the Enterobacteriaceae and on diverse plasmids. It is of clinical concern that the RmtF- and NDM-positive strains identified here show additional resistance to tigecycline and colistin, current drugs of last resort for the treatment of serious bacterial infections.

Unusual extensive physiologic melanin pigmentation of the oral cavity: a clinical presentation

Pigmented lesions are commonly found in the oral cavity. Oral pigmentations may be physiological or pathological in nature. It may represent as a localized anomaly of limited significance or the presentation of potentially life threatening multisystem disease. Oral pigmentation has a multifactorial etiology. Most of the oral pigmentations are physiologic. Evaluation of a patient with pigmented lesions should include a full medical and dental history, extraoral and intraoral examinations. In this article, we report a case of extensive physiologic pigmentation of the oral cavity in a 12 year old female patient, posing a diagnostic challenge.

Gemcitabine in brief versus prolonged low-dose infusion, both combined with carboplatin for advanced non-small cell lung cancer

PURPOSE

Gemcitabine in low-dose prolonged infusion is a treatment with documented activity against a variety of tumors. The present study was conducted to evaluate the efficacy and safety of the combination of gemcitabine at a low-dose prolonged infusion in comparison with standard dose gemcitabine with carboplatin in chemonaive patients with advanced non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Sixty chemonaive patients with stage IIIB or IV NSCLC were included. Patients were randomly assigned 1:1 to receive 350 mg/m 2 gemcitabine in a 6-h infusion on days 1 and 8 and carboplatin area under the serum concentration time curve (AUC) 5 on day 1 versus gemcitabine 1,000 mg/m 2 on days 1 and 8 and carboplatin AUC 5 on day 1 (3-week cycle both). A total of 118 chemotherapy cycles, with a median of 4 cycles per patient (range 2-6), and 134 chemotherapy cycles, with a median of 4.47 cycles per patient (range 3-6) were administered in standard and low infusional dose arm, respectively.

RESULTS

Among patients in the standard arm, 40% had overall response rate (ORR), 33.3% had stable disease and 26.6% had progressive disease, while in low-dose infusional arm, 36.6% had ORR, 36.3% had stable disease and 26.6% had progressive disease (P = 0.992). Median progression-free survival was 5.5 months and 5.4 months, median overall survival was 9.7 months and 10.7 months, and 1-year survival was 33.7% and 36.6% in standard arm and low-dose infusion arm, respectively. Grade 3/4 toxicity was rare.

CONCLUSION

In NSCLC, gemcitabine low-dose prolonged infusion with carboplatin has low toxicity, especially thrombocytopenia, and has an activity comparable with gemcitabine given in higher dose in standard infusion.

Processing fly ash stabilized hydrogen titanate nano-sheets for industrial dye-removal application

We report a new method for the processing of fly ash (FA) stabilized hydrogen titanate nano-sheets in the form of aggregated microspheres. The industrial silica-based FA has been utilized for this purpose which has been surface-modified by coating with the anatase-titania (TiO(2)) via sol-gel. The anatase-TiO(2) coated FA particles are subjected to the hydrothermal treatment in an autoclave under high temperature and pressure conditions in a highly alkaline solution. The hydrothermal conditions cause dissolution of silica resulting in the disintegration of other constituents of FA which are adsorbed in ionic and/or oxidized form on the surface of intermediate product of the hydrothermal treatment of anatase-TiO(2), specifically the hydrogen titanate. The adsorption of FA constituents has resulted in the stabilization of hydrogen titanate in the nano-sheet morphology instead of nanotubes. The FA stabilized hydrogen titanate nano-sheets exhibit higher specific surface-area than that of the hydrogen titanate nanotubes and have been successfully utilized for the removal of an organic synthetic-dye from an aqueous solution via surface-adsorption, involving the electrostatic-attraction and ion-exchange mechanisms operating, in the dark-condition.

Fictitious pseudo Meig’s syndrome: A medical emergency

The present case scenario deals with an acute on chronic symptomatology, and collapsed state of the patient with poor vitals on admission in casualty. Clinical work up pointing to an elevated serum CA 125 levels and USG pelvis suggesting peritoneal adhesions with cystic to firm mass in left ovary and minimal free fluid in abdomen and cul de sac, X Ray chest suggesting right sided Pleural effusion. It was after careful evaluation of the case, with past and present history along with signs, symptommatology and intraoperative findings that differentials like Chronic granulomatous lesions, endometriosis, Neoplastic lesions with metastasis and Meig’s syndrome or Pseudo Meig’s were evaluated. Finally, a diagnosis of genital tuberculosis with enodmetriosis was confirmed on histopathological evaluation. DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5975 JCMSN 2011; 7(1): 57-64

Synthesis, characterization and antiproliferative activity of 1,2-naphthoquinone and its derivatives

In the present study substituted 1,2-naphthoquinones were synthesized, purified and characterized by spectroscopic studies (UV, FT-IR, ¹H NMR, ¹³ C NMR and elemental analysis). These compounds were evaluated for cytotoxicity against a panel of human cancer cell lines (Hep-G₂ for liver sarcoma, MG-63 for osteosarcoma and MCF-7 for human breast cancer). The cells were dosed with these ortho-naphthoquinone derivatives at varying concentrations, and cell viability was measured by a 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay with doxorubicin as positive control. Significant anticancer activities were observed in vitro for some members of the series, and compounds 1,2-naphthoquinone 2-thiosemicarbazone, 1,2-naphthoquinone-2-semicarbazone, 4-amino-1,2-naphthoquinone 2-thiosemicarbazone and 4-amino-1,2-naphthoquinone-2-semicarbazone are active cytotoxic agents against different cancer cell lines with IC₅₀ values in the range of 5.73-17.67 μM. The obtained data suggested that better anticancer activity was linked with introduction of thiosemicarbazone and semicarbazone moiety in 1,2-naphthoquinone ring system. Outcomes of experimentation also reveal that incorporation of amino group in 1,2-naphthoquinone moiety contributes positively for cytotoxic action of compounds. Docking experiments showed a good correlation between their calculated interaction energies with the topoisomerase-II and the observed IC₅₀ values of all these compounds.

Improving cancer chemotherapy with modulators of ABC drug transporters

ATP-binding cassette (ABC) transporters, P-glycoprotein (P-gp, ABCB1) and ABCG2, are membrane proteins that couple the energy derived from ATP hydrolysis to efflux many chemically diverse compounds across the plasma membrane, thereby playing a critical and important physiological role in protecting cells from xenobiotics. These transporters are also implicated in the development of multidrug resistance (MDR) in cancer cells that have been treated with chemotherapeutics. One approach to blocking the efflux capability of an ABC transporter in a cell or tissue is inhibiting the activity of the transporters with a modulator. Since ABC transporter modulators can be used in combination with chemotherapeutics to increase the effective intracellular concentration of anticancer drugs, the possible impact of modulators of ABC drug transporters is of great clinical interest. Another possible clinical use of modulators that has recently attracted attention is their ability to increase oral bioavailability or increase tissue penetration of drugs transported by the transporters. Several preclinical and clinical studies have been performed to evaluate the feasibility and the safety of this approach. The primary focus of this review is to discuss progress made in recent years in the identification and applicability of compounds that may serve as ABC transporter modulators and the possible role of these compounds in altering the pharmacokinetics and pharmacodynamics of therapeutic drugs used in the clinic.

Bilateral symmetrical facial swelling owing to tuberculous gummas

Metastatic tuberculous abscesses and gummas are unusual forms of cutaneous tuberculosis. They result from haematogeneous spread of the mycobacterium from a primary focus during a period of impaired immunity. A 5-year-old boy is reported who presented with spinal tuberculosis and bilateral subcutaneous swelling of the cheeks owing to tuberculous gummas.

Virulence attributes of Helicobacter pylori isolates & their association with gastroduodenal disease

BACKGROUND & OBJECTIVES

Certain genotype(s) of Helicobacter pylori strains may play important role in the development of gastric cancer (GC) and peptic ulcer disease (PUD). This study was undertaken to investigate the association of cagA, cagA3/ region subtypes, babA2 and vacA genotypes of H. pylori with GC, PUD and non-ulcer dyspepsia (NUD) as there are no such studies from India.

METHODS

A total of 348 consecutive adult patients (NUD 241, PUD 45, GC 62) undergoing upper gastrointestinal endoscopy between September 2002 and May 2007 in a tertiary referral centre at Lucknow, north India, were enrolled. H. pylori infection was diagnosed by rapid urease test, culture, histopathology and PCR. Genotyping for cagA, cagA3/ subtypes, babA2 and vacA was performed by PCR using sequence specific primers.

RESULTS

H. pylori infection was higher in patients with PUD than with GC (80 vs. 56.5%, P < 0.01) and NUD (80 vs. 55.2%, P= 0.002). cagA positive H. pylori isolates were detected in 80 per cent in GC, 83.3 per cent in PUD and 76.7 per cent in NUD with no significant difference among them. Only A subtype of cagA3/ was detected and its distribution in GC, PUD and NUD was 68.8, 69.4 and 52.6 per cent respectively. Presence of babA2 genotype was 31.4 per cent and it had significant association with PUD when compared with NUD (52.8 vs. 26.3%, P<0.003). On univariate regression analysis, s1a allele was associated with GC (P<0.050) and s1a/m2 vacA genotype with both GC (P=0.014) and PUD (P=0.016).

INTERPRETATION & CONCLUSIONS

H. pylori infection was strongly associated with PUD with a very high proportion of patients with GC have s1a allele and s1a/m2 vacA genotype. Both s1a/m2 vacA genotype and babA2 are associated with PUD. The study shows that different virulence attributes of H. pylori are involved in different gastroduodenal disorders.