Histomorphometric profile of the corneal response to short-term reverse-geometry orthokeratology lens wear in primate corneas: a pilot study

Purpose: To investigate the histological changes in primate cornea induced by short-term overnight orthokeratology (OK). Methods: Nine young adult primates were used. One animal served as negative control. The remaining 8 animals wore reverse-geometry OK lenses for periods of 4, 8, 16, and 24 hours on 1 eye with the other eye as control. Central and midperipheral corneal thickness, as well as ultrastructural changes in corneal epithelium, stroma and endothelium in response to OK lenses, were evaluated. Results: OK significantly reduced the thickness of the central cornea in all treatment groups. The central corneal thinning was both stromal and epithelial in origin. Substantial midperipheral corneal thickening was seen in 16-hour and 24-hour lens-wear groups and this effect was both stromal and epithelial in origin as well. Histology evidence indicated the primary epithelial response in the central cornea was compression of cells that resulted in wing cells becoming shorter and basal cells being squatted rather than lost or migration of cell layers. These pronounced cell shape changes occurred without compromising the structural integrity of the desmosomes. The thickened corneal epithelium has normal cell layers. The squamous cells have larger surface sizes and are composed of oval instead of flattened nuclei. This implied delayed surface cell exfoliation at the thickened midperipheral epithelium. Physical presence of OK lens over the cornea did not influence the microstructures of microvilli and microplicae, endothelium, and collagen distribution. Conclusions: The primate cornea, particularly the corneal epithelium, responds rapidly to the application of reverse-geometry OK lenses with significant epithelial cell shape alterations with short-term OK lens wear. This finding suggests that the corneal epithelium is moldable in response to the physical forces generated by the OK lenses

Tocotrienol rich fraction supplementation improved lipid profile and oxidative status in healthy older adults: A randomized controlled study

<p>Abstract</p> <p>Background</p> <p>Vitamin E supplements containing tocotrienols are now being recommended for optimum health but its effects are scarcely known. The objective was to determine the effects of Tocotrienol Rich Fraction (TRF) supplementation on lipid profile and oxidative status in healthy older individuals at a dose of 160 mg/day for 6 months.</p> <p>Methods</p> <p>Sixty-two subjects were recruited from two age groups: 35-49 years (n = 31) and above 50 years (n = 31), and randomly assigned to receive either TRF or placebo capsules for six months. Blood samples were obtained at 0, 3^rdand 6^thmonths.</p> <p>Results</p> <p>HDL-cholesterol in the TRF-supplemented group was elevated after 6 months (p < 0.01). Protein carbonyl contents were markedly decreased (p < 0.001), whereas AGE levels were lowered in the > 50 year-old group (p < 0.05). Plasma levels of total vitamin E particularly tocopherols were significantly increased in the TRF-supplemented group after 3 months (p < 0.01). Plasma total tocotrienols were only increased in the > 50 year-old group after receiving 6 months of TRF supplementation. Changes in enzyme activities were only observed in the > 50 year-old group. SOD activity was decreased after 3 (p < 0.05) and 6 (p < 0.05) months of TRF supplementation whereas CAT activity was decreased after 3 (p < 0.01) and 6 (p < 0.05) months in the placebo group. GPx activity was increased at 6 months for both treatment and placebo groups (p < 0.05).</p> <p>Conclusion</p> <p>The observed improvement of plasma cholesterol, AGE and antioxidant vitamin levels as well as the reduced protein damage may indicate a restoration of redox balance after TRF supplementation, particularly in individuals over 50 years of age.</p

Ketamine-xylazine/tiletamine-zolazepam prolonged anesthesia in Cynomolgus monkeys

The physiological effects of a mixture of ketamine, xylazine, tiletamine and zolazepam (KT/XZ), in cynomolgus monkeys during 24 hr anesthesia is described. Eight were induced with ketamine IM and anesthetized with IV KT/XZ. In all, anesthesia was maintained for 24 hours with large decreases in rectal temperature, heart and respiratory rates but moderate hypotension. All monkeys recovered normally 4 hours post-anesthesia. These results suggest that KX/TZ mixture could be used for prolonged anesthesia in cynomolgus monkeys

Mutations in KIF27, GNAS and IFT140 genes in a patient with VACTERL association: a case report

VACTERL association is a rare genetic disorder involving at least three of the following congenital malformations: vertebral defects (V), anal atresia (A), cardiac defects (C), trachea-oesophageal fistula with or without oesophageal atresia (TE), renal anomalies (R) and limb abnormalities (L). Until now, the aetiology of VACTERL association is unknown, particularly at the molecular level. Here, we performed whole exome sequencing (WES) of an infant with VACTERL association. The patient was delivered prematurely at 30 weeks and had 4/6 of the VACTERL malformations. Trio-WES analysis was performed using Torrent Suite and ANNOVAR. Polymorphisms with an allele frequency of >0.01 were excluded, and the remaining variants were filtered based on de novo mutations, autosomal recessive, X-linked and di-genic inheritance traits. In this patient, no homozygous, compound heterozygous or X-linked mutations was associated with VACTERL. However, we identified two heterozygous mutations; KIF27 (ENST00000297814: c.3004A> C:p.N1002H) and GNAS (ENST00000371098: c.205C>A:p.H69N) genes that were inherited from her father and mother respectively. A de novo, IFT140 gene mutation (ENST00000426508: c.683C>G:p.S228C) was also identified in this patient. The VACTERL phenotype in this patient may due to heterozygous mutations affecting KIF27 and GNAS genes, inherited via autosomal recessive trait. In addition, the IFT140 gene mutation may also be involved. These genes are known to be directly or non-directly involved in the sonic hedgehog signalling that is known to be implicated in VACTERL. This is the first report of these genetic mutations in association with VACTERL

Preliminary study shows novel variant detected in the screening of RET gene in Malaysian patients with Hirschsprung’s disease

Hirschsprung’s disease (HSCR) is a disorder associated with congenital absence of ganglion cells in the gastrointestinal tract. Molecular analyses have identified variants in various genes including RET, GDNF, EDN3 and EDNRB that are involved in the development, migration and survival of neural cells. Variants in the receptor tyrosine kinase (RET) are most common and have been identified in 10-20% of sporadic HSCR patients. The objective of this study was to screen for RET gene variants in Malaysian patients with HSCR. Thirty-two patients with HSCR and 30 normal controls were recruited for this study. Mutations were screened using the Polymerase Chain Reaction – Denaturing High Performance Liquid Chromatography (PCR-dHPLC) approach. Mutations identified were then confirmed using Sanger sequencing. We identified one novel rare variant in exon 4 (A268A c807 G>C) in one patient. We also identified the common coding sequence variantsA45A (c135G>A), A432A (c1296A>G), L769L (c2307 T>G) and the G691S in our cohort of patients. In conclusion, our Malaysian patients with HSCR diseases showed the presence of similar RET gene common variants which have been described in other populations. We have also identified a novel variant in exon 4 (A268A)

UKM medical graduates’ perception of their communication skills during housemanship

The art of talking to patients and their relatives does not come naturally to most of us and the ability to put oneself in the patients’ predicament is difficult particularly for the young doctors. To identify the communication abilities of the young doctors, a cross sectional study was carried out on 32 house officers who graduated from UKM in 2004 during their house jobs at different hospitals in Malaysia. A standardized questionnaire was used to collect the data. Fifty nine percent respondents claimed that they had communicated very well with patients while 69% with support staff and 88% with peers. On the other hand 38% and 41% of the respondents claimed they communicated very well with their superiors and families of patients. Only 22% of the graduates’ skills of communication in breaking bad news were very well, while 50% and 81% were very well in counselling patients and taking consent for procedures. Curriculum planners need to emphasize the importance of developing good communication skills in all aspects for the future doctor

Hb lepore/β0-thalassaemia with α+-thalassaemia interactions, a potential diagnostic pitfall

Haemoglobin (Hb) Lepore is a variant Hb consisting of two α-globin and two δβ-globin chains. In a heterozygote, it is associated with clinical findings of thalassaemia minor, but interactions with other haemoglobinopathies can lead to various clinical phenotypes and pose diagnostic challenges. We reported a pair of siblings from a Malay family, who presented with pallor and hepatosplenomegaly at the ages of 21 months and 14 months old. The red cell indices and peripheral blood smears of both patients showed features of thalassaemia intermedia. Other laboratory investigations of the patients showed conflicting results. However, laboratory investigation results of the parents had led to a presumptive diagnosis of compound heterozygote Hb Lepore/β-thalassaemia and co-inheritance α+-thalassaemia (-α3.7). Hb Lepore has rarely been detected in Southeast Asian countries, particularly in Malaysia. These two cases highlight the importance of family studies for accurate diagnosis, hence appropriate clinical management and genetic counselin