Consensus Recommendation for Mouse Models of Ocular Hypertension to Study Aqueous Humor Outflow and Its Mechanisms

Due to their similarities in anatomy, physiology, and pharmacology to humans, mice are a valuable model system to study the generation and mechanisms modulating conventional outflow resistance and thus intraocular pressure. In addition, mouse models are critical for understanding the complex nature of conventional outflow homeostasis and dysfunction that results in ocular hypertension. In this review, we describe a set of minimum acceptable standards for developing, characterizing, and utilizing mouse models of open-angle ocular hypertension. We expect that this set of standard practices will increase scientific rigor when using mouse models and will better enable researchers to replicate and build upon previous findings.

Comparison of different diagnostic modalities for isolation of Mycobacterium Tuberculosis among suspected tuberculous lymphadenitis patients

Tuberculosis is a communicable disease with high morbidity and mortality rates in developing countries. The study's primary objective is to compare conventional methods such as acid-fast bacillus (AFB) culture and microscopy with rapid diagnostic methods. The secondary objective is to compare histopathological and microbiological findings in suspected patients with tubercular lymphadenitis. A total of 111 samples (August 2018 to September 2019) of lymph nodes were processed for AFB microscopy, AFB cultures, drug-susceptibility testing (DST), histopathology, and Xpert Mycobacterium Tuberculosis (MTB)/resistance to Rifampin (RIF) assays. Out of 111 lymph node samples, 6 (5.4%) were positive for AFB smear microscopy, 84 (75.6%) were positive for AFB culture, 80 (70.7%) were positive on Gene Xpert, and 102 (91.8%) were indicative of tuberculosis for histopathology studies. Mycobacteria growth indicator tube (MGIT) culture positivity was 84 (75.6%) higher than solid Lowenstein-Jensen (LJ) culture 74 (66.6%). Positive cultures underwent phenotypic DST. Two cases were Multidrug-resistant (MDR) on DST, while three cases were Rifampicin resistant on Gene Xpert. The sensitivity of Genexpert was (62%) against the conventional AFB culture method. The poor performance of conventional lymphadenitis diagnostic methods requires early and accurate diagnostic methodology. Xpert MTB/RIF test can help in the treatment of multidrug-resistant TB cases. Nonetheless, rapid and conventional methods should be used for complete isolation of Mycobacterium tuberculosis.

Correlation Between Intraoperative and Pathological Findings for Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

This study aimed to examine the correlation between intraoperative and pathological findings for patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) and to determine their prognostic significance.

METHODS

Pathological reports of all colorectal cancer (CRC) patients undergoing CRS/HIPEC between 2009 and 2016 were retrospectively reviewed. Pathological specimens lacking tumor cells were defined as negative pathological specimens (NPS). The intraoperative peritoneal cancer index (PCI) and pathological PCI (excluding NPS) were calculated separately. Receiver operating characteristic (ROC) curves were applied to compare the prognostic value of intraoperative and pathological scoring systems.

RESULTS

For 108 CRC patients, 113 CRS/HIPEC procedures were performed. Of 959 pathological specimens examined, 178 (18.6%) were NPS. Overall, 78 procedures (69%) showed NPS. In 52 procedures (46%), the pathological PCI differed from the intraoperative PCI (∆PCI > 0). The ROC areas for intraoperative PCI and pathological PCI were similar in predicting 1-year overall survival (OS), 2-year OS, and 1-year disease-free survival (all p values not significant). However, for the patients with NPS, the number of positive specimens (containing tumor tissue) was superior to intraoperative PCI in predicting 2-year OS (ROC under the curve areas, 0.69 vs. 0.58, respectively; p = 0.012). In addition, a subgroup of 15 patients with a high ∆PCI (≥ 3) had a more favorable median OS than a matched group of 30 patients with similar intraoperative PCI and a ∆PCI of 0 (median survival not reached vs. 21.6 months, respectively; p = 0.05).

CONCLUSIONS

In the majority of CRC CRS/HIPEC procedures, NPS may be found. Among patients with NPS, pathological correlation may have a prognostic significance.

Change in serum CXCL10 levels during anti-tuberculosis treatment depends on vitamin D status [Short Communication]

Serum levels of the inflammatory C-X-C motif chemokine 10 (CXCL10) are raised in tuberculosis (TB). CXCL10 gene expression is downregulated in monocytes by metabolically active vitamin D3 (1,25dihydroxy vitamin D). Stratification of patients by serum 25hydroxyvitamin D (25[OH]D) levels at baseline showed that treatment-induced decrease in CXCL10 occurred in those with 'insufficient' and 'deficient' but not in those with 'optimal' levels. In the deficient group, 25(OH)D showed an inverse correlation with CXCL10 levels. CXCL10 may thus be a useful biomarker for the follow-up of response to treatment. However, CXCL10 levels should be interpreted taking into account the baseline serum vitamin D levels of the TB patients.

A non-staining chlorhexidine mouthwash? Probably not: a study in vitro

BACKGROUND AND AIM

Tooth staining is a common side effect of chlorhexidine mouth rinses and caused by the interaction of the di-cationic antiseptic with dietary chromogens. A product is now available, which claims an anti-discolouration system (ADS) with one clinical study in support. This study in vitro aims to determine whether two ADS rinses do or do not bind dietary chromogens.

METHOD AND MATERIALS

Optically clear acrylic specimens were cycled through human saliva (2 min), one of the three chlorhexidine rinses (two ADS and a positive control) (2 min) or water and then soaked in tea (60 min). After each cycle the optical density (OD) of specimens were read on a UV/visible spectrophotometer. The exit point was the cycle at which OD was >2.0.

RESULTS

All three rinses exceeded OD 2 at 11 cycles and there was no significant difference in staining for the ADS rinses compared with the positive control rinse.

CONCLUSION

Based on extensive literature for the correlation of this test in vitro with chlorhexidine anti-plaque activity and propensity to stain in vivo these ADS rinses will have the same anti-plaque efficacy and potential to cause stain as established chlorhexidine rinse products.

A comparison of enamel erosion by a new sports drink compared to two proprietary products: a controlled, crossover study in situ

OBJECTIVE

The aim of the study was to measure the erosive potential of a prototype sports drink on enamel in a model in situ.

METHODS

The study was a single centre, single blind, randomised crossover design balanced for residual effects involving 18 subjects. The drinks were the prototype formulation containing calcium and maltodextrin (test), two sports drink products containing sugars (drink with calcium and positive control) and water (negative control). During each 15-day study period, subjects wore a palatal removable appliance carrying two flat human enamel specimens. Drinks were imbibed as 250 ml volumes over 10 min 4 times per day. Loss of enamel was measured on days 5, 10 and 15 using a contacting profilometer.

RESULTS

Very little erosion occurred with the test, drink with calcium and negative control drinks and differences between the test and negative control only reached significance at day 15. The positive control produced progressive erosion over time and significantly more than the test or negative control at all time points.

CONCLUSION

The technology of adding calcium with appropriate pH adjustment, which has been applied previously to soft and carbonated drinks to markedly reduce erosive potential, can be applied to sports drinks to the same end. Significant variation in the carbohydrate composition does not influence this outcome.

15-Fluoro prostaglandin FP agonists: a new class of topical ocular hypotensives

A novel series of 15-fluoro prostaglandins with phenoxy termination of the omega-chain was synthesized and evaluated for binding and functional activation of the prostaglandin FP receptor in vitro and for side effect potential and topical ocular hypotensive efficacy in vivo. Compounds with the 15alpha-fluoride relative stereochemistry displayed EC50 values of <or=20 nM, comparable to the value for the endogenous ligand PGF2alpha. Evaluation of selected ester prodrugs of these 15-fluoro prostaglandins in vivo highlighted their generally low propensity to elicit hyperemia or ocular irritation in rabbits and efficacious intraocular pressure-lowering property in monkeys. In particular 13,14-dihydro-15-deoxy-15alpha-fluoro-16-aryloxy-omega-tetranor-cis-Delta4-PGF2alpha isopropyl ester (24) caused relatively little ocular irritation in rabbits while lowering intraocular pressure in conscious ocular hypertensive monkeys by 39% following a topical ocular dose of 3 microg.

The chemical stain removal properties of 'whitening' toothpaste products: studies in vitro

BACKGROUND

A considerable number of toothpastes are available as tooth whitening products. Most appear to contain ingredients that might remove extrinsic stains rather than change natural tooth colour. Extrinsic stain removal could be achieved by physical or chemical means.

AIM

The purpose of this study was to measure the chemical stain removal properties of a range of whitening toothpaste products and experimental formulations using a standardised method in vitro.

MATERIALS AND METHOD

5 separate studies were conducted involving a total of 39 agents of which 28 were whitening products, 7 were experimental formulations, 2 were oxidising mouthrinses used as positive controls, 1 was a popular fluoride toothpaste product as a benchmark control, and 1 was water as the negative control. The formulations and controls varied in each study. The stain model was saliva/chlorhexidine/tea stain developed on optically clear acrylic to an optical density of at least 2.0. Groups of stained specimens were exposed to standard slurries or solutions of each test agent for 1 minute periods up to 5 minutes. Optical density readings were taken at each 1 minute time point. Analyses were based on per cent stain remaining after 5 minutes and time to 75% stain remaining.

RESULTS

3 toothpaste products achieved 100% stain removal by 5 minutes; 2 of these in 3 out of 4 studies in which they were used. 4 experimental formulations also achieved 100% stain removal. In general agents with high total stain removal also had short times to 75% stain remaining. The majority of agents tested had low total chemical stain removal and prolonged times to 75% stain remaining. A few agents were little different from water and several similar in effect to the conventional fluoride toothpaste. This method in vitro tests agents under the best case scenario conditions for chemical stain removal.

CONCLUSION

Only a small number of the whitening toothpaste products have good chemical stain removal potential; the majority are unlikely to achieve their claimed benefits through chemical stain removal. There is clearly a need for further data on the actual effects of such products using both methods in vitro and particularly in vivo or in situ.