Small Lid Research Articles

Structural basis for the substrate specificity switching of lysoplasmalogen-specific phospholipase D from Thermocrispum sp. RD004668.

Lysoplasmalogen-specific phospholipase D (LyPls-PLD) hydrolyzes choline lysoplasmalogen to choline and 1-(1-alkenyl)-sn-glycero-3-phosphate. Mutation of F211 to leucine altered its substrate specificity from lysoplasmalogen to 1-O-hexadecyl-2-hydroxy-sn-glycero-3-phosphocholine (lysoPAF). Enzymes specific to lysoPAF have good potential for clinical application, and understanding the mechanism of their activity is important. The crystal structure of LyPls-PLD exhibited a TIM barrel fold assigned to glycerophosphocholine phosphodiesterase, a member of glycerophosphodiester phosphodiesterase. LyPls-PLD possesses a hydrophobic cleft for the binding of the aliphatic chain of the substrate. In the structure of the F211L mutant, Met232 and Tyr258 form a "small lid" structure that stabilizes the binding of the aliphatic chain of the substrate. In contrast, F211 may inhibit small lid formation in the wild-type structure. LysoPAF possesses a flexible aliphatic chain; therefore, a small lid is effective for stabilizing the substrate during catalytic reactions.

New Method for Removing Thermosensitive Acrylic Punctal Plugs From Lacrimal Puncta

This study explored a new method for removing thermosensitive acrylic punctal plugs from lacrimal puncta. A total of 14 dry eye patients (14 eyes), who required the removal of thermosensitive acrylic punctal plugs from the lacrimal puncta because of serious complications, were recruited. Among the 14 patients, lacrimal punctal granuloma formation occurred in 3 patients, tearing occurred in 6 patients, canaliculitis occurred in 3 patients, and chronic inflammation of the ocular surface occurred in 2 patients. The plugs were removed using a new method. Briefly, after local anesthesia was administered, a small lid clamp was used to flip the eyelid outward. After the application of the lid clamp, the plug could be removed without the use of any additional tools if the lacrimal punctum was large enough. If the lacrimal punctum was not large enough, microforceps were used to expand the lacrimal punctum before the application of the lid clamp. If the plug still could not be removed after the expansion of the lacrimal punctum, we moved the small lid clamp from the distal side of the lacrimal ductule to the lacrimal punctum. Using this method, the plug was successfully removed in all of the patients. This is a simple and effective method for removing thermosensitive acrylic punctal plugs from lacrimal puncta. : http://www.clinicaltrials.gov. Unique identifier: ChiCTR-IPR-14005476.

Evaluation of jar lid design characteristics by older women with hand use limitations

The study evaluated several lid design characteristics (diameter, height, top shape, side shape, and surface texture) by means of controlled laboratory testing with older women with hand function limitations. A subjective evaluation process was applied to examine main effects and interactions of lid design characteristics on usability, determined by participants' perceptions of effort and discomfort. Results showed that lid height was the most important design characteristic associated with usability. For 42 mm diameter lids, designs perceived as best were ones with taller height, hexagonal top shape, and convex side shape. For 28 mm diameter lids, the best designs were ones with taller height and hexagonal top shape. Additionally, when the smaller lid's side shape was flat, a serrate surface texture provided some advantages, particularly for subjects with more severe hand dysfunction. This information could be used by package designers to improve jar lid usability for a growing sector of consumers.

Small incision versus conventional transcutaneous levator resection in the management of ptosis with good and excellent levator action

Purpose The aim of this study is to compare small incision levator and conventional transcutaneous levator resection in the management of cases of ptosis with good and excellent levator action. Patients and methods This is a prospective comparative study that included 30 patients with unilateral ptosis, 16 cases with congenital, and 14 cases with aponeurotic ptosis. Levator action was good (>10 mm levator excurtion) in 20 cases and excellent (>15 mm levator excurtion) in 10 cases. Fifteen cases (group B) were operated through a small (8 mm) upper lid crease incision through which sutures were passed from the tarsal border to the levator muscle at the target distance and 15 cases (group A) were operated through a conventional transcutaneous levator resection. Results This study included 30 cases of unilateral ptosis. They were divided into two groups: group A was operated by a conventional technique and group B was operated by a small incision technique. In group A, 80% of cases were fully corrected, 13.3% were undercorrected, and 6.7% were over corrected; however, in group B, 86.7% were fully corrected and 13.3% were undercorrected. The mean surgical time in group A was 49.5 ± 5.9 and that in group B was 28.1 ± 5.2. Conclusion This study shows that small incision levator muscle resection is equally effective as the conventional transcutaneous levator resection for the management of ptosis, with good and excellent levator action, with better lid contour and quicker time.

Structure and Function of the RedJ Protein, a Thioesterase from the Prodiginine Biosynthetic Pathway in Streptomyces coelicolor

Prodiginines are a class of red-pigmented natural products with immunosuppressant, anticancer, and antimalarial activities. Recent studies on prodiginine biosynthesis in Streptomyces coelicolor have elucidated the function of many enzymes within the pathway. However, the function of RedJ, which was predicted to be an editing thioesterase based on sequence similarity, is unknown. We report here the genetic, biochemical, and structural characterization of the redJ gene product. Deletion of redJ in S. coelicolor leads to a 75% decrease in prodiginine production, demonstrating its importance for prodiginine biosynthesis. RedJ exhibits thioesterase activity with selectivity for substrates having long acyl chains and lacking a β-carboxyl substituent. The thioesterase has 1000-fold greater catalytic efficiency with substrates linked to an acyl carrier protein (ACP) than with the corresponding CoA thioester substrates. Also, RedJ strongly discriminates against the streptomycete ACP of fatty acid biosynthesis in preference to RedQ, an ACP of the prodiginine pathway. The 2.12 Å resolution crystal structure of RedJ provides insights into the molecular basis for the observed substrate selectivity. A hydrophobic pocket in the active site chamber is positioned to bind long acyl chains, as suggested by a long-chain ligand from the crystallization solution bound in this pocket. The accessibility of the active site is controlled by the position of a highly flexible entrance flap. These data combined with previous studies of prodiginine biosynthesis in S. coelicolor support a novel role for RedJ in facilitating transfer of a dodecanoyl chain from one acyl carrier protein to another en route to the key biosynthetic intermediate 2-undecylpyrrole.

Occult orbito-cranial penetrating injury by pencil: Role of beta tracer protein as a marker for cerebrospinal fluid leakage

Orbito-cranial foreign bodies present a treacherous situation that can escape detection. The only evidence of these foreign bodies may be the entry wound in the form of a small lid laceration. A two-year-old boy presented with right upper lid laceration following a fall two hours back. Analysis of the fluid around the wound revealed a beta-tracer protein (beta-TP) value of 33.5 mg/l suggestive of cerebrospinal fluid (CSF). Three-dimensional computed tomography (CT) scan revealed a foreign body measuring 4.2 cm × 0.8 cm passing from the orbital roof to the frontal lobe. The foreign body tract was explored through the eyelid laceration and a broken pencil was removed followed by dural patch graft. The patient developed no ocular or intracranial complications. Beta-TP, a highly specific marker of CSF is routinely used in screening patients of neurosurgery and otolaryngology with CSF leaks, however, its use has never been reported in ophthalmic literature based on an online PubMed search.

3′-[4-Aryl-(1,2,3-triazol-1-yl)]-3′-deoxythymidine Analogues as Potent and Selective Inhibitors of Human Mitochondrial Thymidine Kinase

In an effort to increase the potency and selectivity of earlier identified substrate-based inhibitors of mitochondrial thymidine kinase 2 (TK-2), we now describe the synthesis of new thymidine analogues containing a 4- or 5-substituted 1,2,3-triazol-1-yl substituent at the 3'-position of the 2'-deoxyribofuranosyl ring. These analogues were prepared by Cu- and Ru-catalyzed cycloadditions of 3'-azido-3'-deoxythymidine and the appropriate alkynes, which produced the 1,4- and 1,5-triazoles, respectively. Selected analogues showed nanomolar inhibitory activity for TK-2, while virtually not affecting the TK-1 counterpart. Enzyme kinetics indicated a competitive and uncompetitive inhibition profile against thymidine and the cosubstrate ATP, respectively. This behavior is rationalized by suggesting that the inhibitors occupy the substrate-binding site in a TK-2-ATP complex that maintains the enzyme's active site in a closed conformation through the stabilization of a small lid domain.

Structure of the Alkalohyperthermophilic Archaeoglobus fulgidus Lipase Contains a Unique C-Terminal Domain Essential for Long-Chain Substrate Binding

Several crystal structures of AFL, a novel lipase from the archaeon Archaeoglobus fulgidus, complexed with various ligands, have been determined at about 1.8 Å resolution. This enzyme has optimal activity in the temperature range of 70–90 °C and pH 10–11. AFL consists of an N-terminal α/β-hydrolase fold domain, a small lid domain, and a C-terminal β-barrel domain. The N-terminal catalytic domain consists of a 6-stranded β-sheet flanked by seven α-helices, four on one side and three on the other side. The C-terminal lipid binding domain consists of a β-sheet of 14 strands and a substrate covering motif on top of the highly hydrophobic substrate binding site. The catalytic triad residues (Ser136, Asp163, and His210) and the residues forming the oxyanion hole (Leu31 and Met137) are in positions similar to those of other lipases. Long-chain lipid is located across the two domains in the AFL–substrate complex. Structural comparison of the catalytic domain of AFL with a homologous lipase from Bacillus subtilis reveals an opposite substrate binding orientation in the two enzymes. AFL has a higher preference toward long-chain substrates whose binding site is provided by a hydrophobic tunnel in the C-terminal domain. The unusually large interacting surface area between the two domains may contribute to thermostability of the enzyme. Two amino acids, Asp61 and Lys101, are identified as hinge residues regulating movement of the lid domain. The hydrogen-bonding pattern associated with these two residues is pH dependent, which may account for the optimal enzyme activity at high pH. Further engineering of this novel lipase with high temperature and alkaline stability will find its use in industrial applications.

Numerical simulation of unsteady mixed convection in a driven cavity using an externally excited sliding lid

A numerical investigation of unsteady laminar mixed convection heat transfer in a lid driven cavity is executed. The forced convective flow inside the cavity is attained by a mechanically induced sliding lid, which is set to oscillate horizontally in a sinusoidal fashion. The natural convection effect is sustained by subjecting the bottom wall to a higher temperature than its top counterpart. In addition, the two vertical walls of the enclosure are kept insulated. Discretization of the governing equations is achieved through a finite element scheme based on the Galerkin method of weighted residuals. Comparisons with previously reported investigations are performed and the results show excellent agreement. Temporal variations of streamlines, isotherms, and dimensionless drag force, and Nusselt number are presented in this investigation for various pertinent dimensionless groups. Fluid flow and heat transfer characteristics are examined in the domain of the Reynolds number, Grashof number and the dimensionless lid oscillation frequency such that: 10 2 ⩽ Re ⩽ 10 3 , 10 2 ⩽ Gr ⩽ 10 5 and 0.1 ⩽ ϖ ⩽ 5 . The working fluid is assigned a Prandtl number of 0.71 throughout this investigation. The obtained results reveal that the Reynolds number and Grashof number would either enhance or retard the energy transport process and drag force behavior depending on the conduct of the velocity cycle. Moreover, relatively small lid oscillation values are found to constrain the lid associated motion to a shallow depth from the sliding lid plane.

Loss of an eye in a baby from keratitis initially managed as conjunctivitis

is one pathogen known for this,as appears to have occurred in this patient. The symptoms ofconjunctivitis include irritation, stinging and discharge, whereassevere foreign body sensation, pain, photophobia and blurredvision should raise suspicion of keratitis. Signs differentiatingconjunctivitis from keratitis are listed in Box 2.Examination findings are most important in young children,because they cannot describe the symptoms. However, examiningthe eyes of distressed babies and children can be extremelydifficult. A few drops of local anaesthetic can make examinationeasier. Restraining a child or wrapping a baby in a sheet may benecessary. With a baby, a small lid speculum may be necessary togain an adequate view, and magnification and a bright light sourceare essential. Progressive ulceration can lead to corneal perforationand endophthalmitis, as in the baby described in this report.Swabs should be considered when there is profuse discharge.

Ambivalent effects of added layers on steady kinematic dynamos in cylindrical geometry: application to the VKS experiment

The intention of the “von Kármán sodium” (VKS) experiment is to study the hydromagnetic dynamo effect in a highly turbulent and unconstrained flow. Much effort has been devoted to the optimization of the mean flow and the lateral boundary conditions in order to minimize the critical magnetic Reynolds number R m c and hence the necessary motor power. The main focus of this paper lies on the role of “lid layers”, i.e. layers of liquid sodium between the impellers and the end walls of the cylinder. First, we study an analytical test flow to show that lid layers can have an ambivalent effect on the efficiency of the dynamo. The critical magnetic Reynolds number shows a flat minimum for a small lid layer thickness, but increases for thicker layers. For the actual VKS geometry it is shown that static lid layers yield a moderate increase of R m c by approximately 12 per cent. A more dramatic increase by 100 till 150 per cent can occur when some rotational flow is taken into account in those layers. Possible solutions of this problem are discussed for the real dynamo facility.

Crystal structure of nitrile hydratase from a thermophilic Bacillus smithii

The crystal structure of the nitrile hydratase (NHase) from Bacillus smithii SC-J05-1 was determined. Our analysis of the structure shows that some residues that seem to be responsible for substrate recognition are different from those of other NHases. In particular, the Phe52 in the β subunit of NHase from B. smithii covers the metal center partially like a small lid and narrows the active site cleft. It is well known that the NHase from B. smithii especially prefers aliphatic nitriles for its substrate rather than aromatic ones, and we can now infer that the Phe52 residue may play a key role in the substrate specificity for this enzyme. This finding leads us to suggest that substitution of these residues may alter the substrate specificity of the enzyme.

Results of the Hughes operation

There are several methods for the repair of large defects of the upper and lower eyelids, but we prefer the original procedure by Hughes. This operation has been used traditionally for partial and total reconstruction of lid defects after tumour resection in 7-10%. The advantage of this technique is the rebuilding of the eyelid with the lid tissue itself. We present the results of operations by the Hughes method over a 10-year-period. Between 1986 and 1996 we operated on 60 out of 600 patients with neoplastic tumours of the eyelids and 1 patient with a large traumatic defect of the upper eyelid by the original operation method of Hughes. We report on a retrospective study of 55 patients including 30 males and 25 females with a mean age of 68.6 years. The duration of the histories of the tumours ranged from 2 month to 10 years. The lower eyelids were involved in 46 patients and the upper lids in 9. In 80% (45 patients) we found basal cell carcinomas and in 17% (9 patients) squamous cell carcinomas. Therapy of tumours: 50 out of 54 tumours (92.6%) were resected in sano and 4 not. During the dissection of the lids we carried out a tissue biopsy but no further tumour tissue was found in three patients. The fourth patient needed three further operations before recovery. In six patients we recognised a new tumour, one of them suffered from Lewandowsky-Lutz-Syndrom, developed a new tumour in the orbit and required exenteration orbitae. Early complications: arterial bleeding in one case, in four cases mild dehiscence of the wound between the graft and the remaining lid, in two patients with high risk, infection of the wound, one rejection of the skin graft, one small infiltration of the cornea. Late complications: In six cases we recognised recurrence of the tumour and three patients with entropium and seven patients with heavy trichiasis needed revision. Minor complications such as mild distichiasis, partial incomplete closing of the lids, a smaller lid fissure or notching of the canthus of the lid which did not require revision. The results were quite satisfactory from a functional and aesthetic point of view. We recommend the operation method of Hughes for reconstruction of large defects of the eyelids of any reason.

Corneal Edema After Overnight Lid Closure of Rabbits Wearing Silicone Rubber Contact Lenses

Elastofilcon A silcone rubber contact lenses induce less corneal swelling than no lens wear during sleep, and increasing the central thickness and volume of the lens does not influence its overnight performance. We sought to elucidate whether a silicone rubber lens can promote the distribution of atmospheric O2 on the cornea through a small interpalpebral opening under closed-eye conditions. Three groups of rabbit eyes comprised 12 eyes wearing Silflex (Dk 79.8 barrer) lenses, 12 with elastofilcon A (Dk 340 barrer) lenses, and 12 without lenses. All eyes were surgically closed overnight; six eyes in each group had a complete lid closure and six eyes had a partial tarsorrhaphy that left a small, central gap approximately 3 mm in length. When the lids were opened the next morning, the partially closed elastofilcon A eyes showed less corneal swelling (6.2 +/- 1.4%) than the partially closed no-lens eyes did (9.6 +/- 1.3%) (p less than 0.01), whereas the partially closed Silflex eyes were significantly more swollen (12.8 +/- 2.1%) (p = 0.01) than the other two partially closed groups were. The completely closed eyes showed no significant difference in corneal swelling among the groups. These results indicate that small lid gaps during sleep may lead to less corneal swelling when elastofilcon A lenses are used than with no lenses.

Pseudoptosis in a patient with maxillary sinus mucocele

The authors examined a patient who complained of ptosis on the right side. Examination of the affected eye revealed a narrow lid fissure, an upward displaced globe, and good levator function. Computed tomography indicated a right maxillary sinus mucocele with an intraorbitally displaced bone fragment of the orbital floor. The mucocele was excised and the orbital floor was reconstructed surgically. Immediately thereafter the right lid fissure opened to normal size. The authors believe that the small lid fissure simulating ptosis in this patient may have been caused by the mucocele, suggesting that maxillary sinus mucocele should be added to the list of factors predisposing to pseudoptosis.

異形吸虫類に関する研究

Metacercariae of sickle-heterophyes parasitic on the muscle of mullet taken from Oyodo River, Miyazaki Prefecture were collected through the artificial gastic juice digestion method and each groop of 100 metacercariae was given to every 10 chickens (120g150g in weight) and also to every 10 rats (55g72g in weight) through mouth. After that, one of each was dissected every 24 hours and observation was made on the parasitic site within the intestine, total number, infection rate, development of the body, and ovulation.These are the results. The parasitic site is mainly below the middle part of the small intestine in both the hosts. The infection rate to metacercariae given to the hosts is 25.6% in chicken. 22.5% in rat. Ovulation begins on the sixth day in chicken, on the seventh day in rat. Development of trematodes in the hosts is almost the same in both the cases. Size of the body at the time when ten days have passed since infcetion is 0.825mm in length, 0.354mm in maximal width. Oral sucker, 0.057mm×0.051mm. Ventral sucker, 0.040mm×0.040mm. Penial sac, 0.125×0.035mm. Ovary, 0.068×0.067mm. Right testicle, 0.1000×0.095mm. Left testicle, 0.095×0.085mm. As for the movement of eggs in the uterus, the eggs appear in the ootype, then move leftwards, attain the part between the posterior end of the left intestine and the left testicle, and there turn around to proceed rightwards. Next attain the part between the posterior end of the right intestine and the right testicle via anterior edge of the ovary. With further growth of the body, the eggs, passing the anterior edge of the right testicle, descend through the middle part between the testicles, i.e., the excretory bladder, attain the posterior end of the body and there turn around, ascend, attain the anterior end of the penial sac via the interior of the ovary, or the exterior when the body has become adult. Then pass before the posterior end of the penial sac and lastly wander out from the ventral sucker. The posterior end of the uterus is connected with ejaculatory duct and the duct thus connected opens at the ventral. The size of egg is 0.0256mm×0.014mm. The egg has a small lid in the anterior, with sharp projection in its center. Eggs in different hosts are not different in size.

II. Further Objects from the Cave of Trapeza

The following objects, all said to be from the Cave of Trapeza or immediately outside, were recovered from the peasants in 1937 and 1938.1. (Fig. 1a). Pedestalled cup in mottled limestone. This joins one of the fragments numbered 16 in the catalogue. Height 4·4 cms., diameter 5·3 cms.; cf. a finer example from Mokhlos, Tomb XXI, No. 7. Probably EM II but, owing to its coarser shape might be EM III.2. (Fig. 1a). Small lid in brown steatite pierced for strings to tie it on to a vase. Height 1·0 cm., greatest diameter 2·9 cms. Cf. caps of clay vases EM I, e.g., from Agios Onouphrios (P of M I Fig. 23). EM II.