Blindness following medial maxillectomy

Medial maxillectomy via lateral rhinotomy approach is used in the treatment for tumours affecting the lateral nasal wall. The most frequent complications are crusting, epicanthal scarring and epiphora. The authors report a rare case of blindness secondary to indirect optic neuropathy following medial maxillectomy undertaken to treat a malignant melanoma arising in the lateral nasal wall. It is important to keep in mind, the possibility of this rare complication, while patients are being counselled preoperatively for medial maxillectomy.     

Solvent-dependent regio- and stereo-selective reactions of 3-formylchromones with 2-aminobenzothiazoles and transacetalization efficiency of the product 3-((benzo[d]thiazol-2-ylimino)butyl)-4H-chromen-4-one

Using 2-propanol as the solvent, 3-formylchromones and 2-aminobenzothiaoles formed corresponding imines, while 1° and 2°-alcohols formed the corresponding 2-alkoxy-3-enamines with selectivity for the Z-isomer. Changing the substrates with similar molecules such as 3-formylchromone with quinoline-, quinolone- and indole-3-carbaldehydes sometimes resulted in the formation of the corresponding imines, whereas replacing 2-aminobenzothiazole with amides resulted in the formation of acetals. Considering the effect of the solvent, replacing alcohols with the aprotic solvents THF and CH₂Cl₂ resulted in the formation of imines and enamines, which are the characteristic reactions of 2-propanol and other 1° and 2°-alcohols, respectively. 2-Alkoxy-3-enamines were found to undergo transacetalization with both short and long chain alcohols. The novelty of these reactions is that they did not require an external catalyst, all the reactions were performed at the same temperature, and purification was achieved by filtration. The transacetalization we performed herein is a new concept, which has not been reported to date. In contrast, other similar reactions, such as transalkoxylation, transalkylation, and transetherification, are performed on a commercial scale using expensive catalysts such as Otera''s catalyst. The highly sensitive nature of 3-formylchromones towards variations in the substrates and solvents to form different products and the reason behind the selective formation of the Z-isomer of 2-alkoxy-3-enamines and its transacetalization efficiency need further studies to understand the reaction mechanism and possibly other factors such as solvent effects.

2-Propanol forms lmine (4), other alcohols forms enamine (3) which can undergo transacetalization and replacing 2 with amides forms acetals (5).     

Selective inhibition of intestinal 5-HT improves neurobehavioral abnormalities caused by high-fat diet mice

Recent literature reported the adverse effects of high-fat diet (HFD) on animal’s emotional and cognitive function. An HFD-induced obesity/hyperlipidemia is accompanied by hormonal and neurochemical changes that can lead to depression. The important roles of gut-derived serotonin (5-Hydroxytryptamine, 5-HT) during this processing have been increasingly focused. Hence, to determine the potential role of gut-derived serotonin, HFD model was established in C57BL/6 mice. At the 4th week of feeding, a pharmacologic inhibitor of gut-derived 5-HT synthesis LP533401 (12.5 mg/kg/day), simvastatin (SIM) (5 mg/kg/day) and benzafibrate (BZ) (75 mg/kg/day) were administered for two weeks by oral gavage. Then, intraperitoneal glucose tolerance test (IPGTT), open field test (OFT), tail suspension test (TST), forced swim test (FST), sucrose preference test (SPT) were used to evaluate metabolic and neurobehavioral performances. Immunohistochemical staining, real-time quantitative PCR and other methods were to explore possible mechanisms. It was found that HFD feeding and drug treatments had some significant effects on neurobehaviors and brain: (1) All administrations reduced the total cholesterol (TC) and triglyceride (TG) parametric abnormality caused by HFD. LP533401 and SIM could significantly improve the impaired glucose tolerance, while BZ had no significant effect. (2) LP533401, SIM and BZ alleviated depression-like behavior of HFD mice in OFT, TST, FST and SPT. (3) LP533401 and SIM reversed the inhibition of Tryptophan Hydroxylase 2, Tph2 gene expression and the activation of Indoleamine 2,3-dioxy-Genase, IDO expression in HFD-treated brain, whereas BZ did not. (4) LP533401, SIM and BZ restored the inhibitory expression of 5-HT_1A receptor in HFD hippocampus. Conclusions: Selective inhibition of intestinal 5-HT can attenuate depressive-like behavior, reduce 5-HT_1AR impairment in hippocampus and correct abnormal 5-HT pathway in brain while ameliorating HFD-induced glucose intolerance. Further experiments are warranted to define the adequate strategy of targeting peripheral 5-HT for the treatment of such co-morbidity.

     

In vitro Gd‐DTPA relaxometry studies in oxygenated venous human blood and aqueous solution at 3 and 7 T

In vitro T₁ and T₂^* relaxivities (r₁ and r₂^*) of Gd‐DTPA (GaD) in oxygenated human venous blood (OVB) and aqueous solution (AS) at 3 and 7 T were calculated. GaD concentrations ([GaD]) in OVB and AS were prepared in the range 0‐5 mM. All measurements were acquired at 37 ± 2 °C. At both 3 and 7 T, a linear relationship was observed between [GaD] and R₁ in both AS and OVB. At 7 T, r₁ in AS decreased by 7.5% (p = 0.045) while there was a negligible change in OVB. With respect to R₂^*, a linear relationship with [GaD] was only observed in AS, while a more complex relationship was observed in OVB; quadratic below and linear above 2 mM at both field strengths. There was a significant increase of over 4‐fold in r₂^* with GaD in OVB at 7 T (for [GaD] above 2 mM, p <<0.01) as compared with 3 T. Furthermore, in comparison to r₁, r₂^* in AS was less than 2‐fold higher at both field strengths while in OVB it was ~20‐fold and ~90‐fold higher at 3 and 7 T, respectively. This observation emphasizes the importance of r₂^* knowledge at high magnetic fields, ≥3 T. The comparison between r₁ and r₂^* presented in this work is crucial in the design and optimization of high‐field MRI studies making use of paramagnetic contrast agents. This is especially true in multiple compartment systems such as blood, where r₂^* dramatically increases while r₁ remains relatively constant with increasing magnetic field strength. Copyright © 2014 John Wiley & Sons, Ltd.     

Bilateral V-Y advancement flaps for the management of extensive defects of the perianal skin

Premalignant and malignant conditions of the skin may sometimes require excision of extensive areas of the skin and subcutaneous tissues. Coverage of the ensuing raw area may be afforded by allowing healing by secondary intention, skin grafts, or flaps. Wide excision of the perianal skin poses special problems. We describe the use of bilateral V-Y advancement flaps for the management of an extensive defect resulting from the wide excision of squamous cell carcinoma arising in scarred perianal skin.     

Extensive maxillary sinus pneumatization

AIM: To determine the incidence of variations of maxillary sinus pneumatization especially when it is extensive and the associated anomalies. STUDY DESIGN: Two hundred consecutive direct coronal paranasal sinus computed tomography (CT) scans were reviewed retrospectively. Extensive maxillary sinus pneumatization (EMSP) was defined as one in which the largest horizontal and/or vertical dimension of the maxillary sinus equalled or exceeded 90% of the corresponding diameter of the orbit. Further subtype I, II & III were defined depending on whether the pneumatization was extensive in one dimension (horizontal or vertical), two dimensions (horizontal & vertical) and by the presence of sphenomaxillary plate, intermaxillary plate or extension into frontal recess. RESULTS: EMSP was found in 8%, of these 7% were bilateral and 1% was unilateral. (Subtype I, II and III constituting 1%, 3% & 4% respectively). CONCLUSION: EMSP has been defined as a group and a classification proposed. EMSP will result in an atypical clinical picture, has a role in the pathogenesis of frontal sinusitis in some cases and may predispose injury to the orbit during endoscopic sinus surgery (ESS).     

Effects of two chronic stresses on mental state and hair follicle melanogenesis in mice

Growing bodies of data show that psychological stress can be associated with hair loss and vitiligo. Researchers have revealed that stress could indeed inhibit hair growth in vivo, but the relationship between chronic stress and melanogenesis remains unknown. In this study, we established two types of stress models, chronic restraint stress (CRS) and chronic unpredicted mild stress (CUMS) mice models, and explored the possible role of stress in mice hair follicle melanogenesis. We found that stress changed hippocampal morphology, decreased 5‐HT level in brain and skin and down‐regulated 5‐HT1A receptor expression in hippocampal CA1 region and skin. The alterations of 5‐HT and 5‐HT1A receptor might be a threshold of central stress to associate with the behaviour changes. Both two stresses caused cellular damage of melanocytes and inhibition of keratinocytes proliferation in HF, which made the synthetic pigment loss. CRS which was considered primarily as a “psychological” stressor had the lower melanin production in HF, as well as the level of 5‐HT in skin was down‐regulated more than those in CUMS group.     

Giant vertebro-basilar aneurysm: an unusual cerebello-pontine angle lesion

Acoustic neuromas (vestibular schwannomas) comprise more than 90 per cent of all cerebello-pontine angle (CPA) lesions. We present a rare case of a giant vertebro-basilar aneurysm presenting as a CPA lesion. The general condition of the patient precluded the completion of the magnetic resonance (MR) sequences. The clinical and limited radiological results (T2 images alone, the features of which were not specific) initially did not lead to a specific diagnosis. To obtain further radiological information a computed tomography (CT) scan with contrast was performed and this revealed the lesion to be an aneurysm. The diagnostic difficulties and the treatment dilemmas of such a lesion are discussed. The importance of fine, axial, post-contrast CT arteriography with three-dimensional reconstruction, MR angiography and digital subtraction angiography are highlighted. The limitations of MR imaging in patients with CPA lesions are discussed.