Acute Bilateral Orbital Myositis Following Covid 19 Vaccination.

The authors present a case of acute bilateral orbital myositis occurring 24 hours after the administration of the mRNA1273 vaccination for COVID 19. The patient was presented with right proptosis, with orbital imaging demonstrating bilateral enlargement of all the extraocular muscles. Serological investigation did not reveal a precipitating cause or underlying disease process. The presenting features resolved entirely following treatment with methylprednisolone and the patient remains asymptomatic.

Probable IGG4 related ophthalmic disease presenting with uveitis.

We present a case of an uncommon presentation of IgG4-related ophthalmic disease (ROD). A 58-year-old female presented with unilateral acute anterior uveitis of the right eye, which progressed to scleritis with the development of an associated orbital mass despite treatment with oral glucocorticoid. Initial histopathology of an orbital biopsy was non-diagnostic and continued progression of the disease lead to complete loss of vision in the right eye. The development of uveitis in the previously unaffected left eye led to the decision for enucleation of the right globe and further orbital biopsy. Histopathology revealed features supporting IgG4-related ophthalmic disease. Oral glucocorticoid therapy failed to induce remission, and rituximab therapy was initiated, leading to a rapid resolution in her symptoms. Other cases with a similar presentation report a poor visual prognosis, highlighting the need for prompt diagnosis and treatment of uveitis associated with signs of orbital or scleral involvement.

The investigation of prostatic calcifications using µ-PIXE analysis and their dosimetric effect in low dose rate brachytherapy treatments using Geant4.

Low dose rate brachytherapy is a widely used modality for the treatment of prostate cancer. Most clinical treatment planning systems currently in use approximate all tissue to water, neglecting the existence of inhomogeneities, such as calcifications. The presence of prostatic calcifications may perturb the dose due to the higher photoelectric effect cross section in comparison to water. This study quantitatively evaluates the effect of prostatic calcifications on the dosimetric outcome of brachytherapy treatments by means of Monte Carlo simulations and its potential clinical consequences.Four pathological calcification samples were characterised with micro-particle induced x-ray emission (µ-PIXE) to determine their heavy elemental composition. Calcium, phosphorus and zinc were found to be the predominant heavy elements in the calcification composition. Four clinical patient brachytherapy treatments were modelled using Geant4 based Monte Carlo simulations, in terms of the distribution of brachytherapy seeds and calcifications in the prostate. Dose reductions were observed to be up to 30% locally to the calcification boundary, calcification size dependent. Single large calcifications and closely placed calculi caused local dose reductions of between 30-60%. Individual calculi smaller than 0.5 mm in diameter showed minimal dosimetric impact, however, the effects of small or diffuse calcifications within the prostatic tissue could not be determined using the methods employed in the study. The simulation study showed a varying reduction on common dosimetric parameters. D90 showed a reduction of 2-5%, regardless of calcification surface area and volume. The parameters V100, V150 and V200 were also reduced by as much as 3% and on average by 1%. These reductions were also found to relate to the surface area and volume of calcifications, which may have a significant dosimetric impact on brachytherapy treatment, however, such impacts depend strongly on specific factors in the patient's individual treatment. These factors include the number, size, composition and spatial distribution of calcifications in the prostate as well as the distribution of brachytherapy seeds.

Actin reorganization as the molecular basis for the regulation of apoptosis in gastrointestinal epithelial cells.

The gastrointestinal (GI) epithelium is a rapidly renewing tissue in which apoptosis represents part of the overall homeostatic process. Regulation of apoptosis in the GI epithelium is complex with a precise relationship between cell position and apoptosis. Apoptosis occurs spontaneously and in response to radiation and cytotoxic drugs at the base of the crypts. By contrast, the villus epithelial cells are extremely resistant to apoptosis. The molecular mechanism underlying this loss of function of villus epithelial cells to undergo apoptosis shortly after their exit from the crypt is unknown. In this study we demonstrate for the first time, that deletion of two homologous actin-binding proteins, villin and gelsolin renders villus epithelial cells extremely sensitive to apoptosis. Ultrastructural analysis of the villin-gelsolin(-/-) double-knockout mice shows an abnormal accumulation of damaged mitochondria demonstrating that villin and gelsolin function on an early step in the apoptotic signaling at the level of the mitochondria. A characterization of functional and ligand-binding mutants demonstrate that regulated changes in actin dynamics determined by the actin severing activities of villin and gelsolin are required to maintain cellular homeostasis. Our study provides a molecular basis for the regulation of apoptosis in the GI epithelium and identifies cell biological mechanisms that couple changes in actin dynamics to apoptotic cell death.

Effect of controlled hypercapnia on cerebrospinal fluid pressure and operating conditions during transsphenoidal operations for pituitary macroadenoma.

Controlled hypercapnia was assessed for its effectiveness in raising cerebrospinal fluid pressure to enable descent of the suprasellar portion of pituitary macroadenomas during transsphenoidal surgery. The result was compared in a randomized, single blind trial with intermittent boluses of saline injected intrathecally. Intrathecal pressures were monitored in both groups. Twenty-seven of 29 patients in the study group and 25 of 28 patients in the control group reached the target pressure of 20 mm Hg. The mean ETCO2 at the time of maximum pressure was 42.34 +/- 4.75 mm Hg in the study group and 29.81 +/- 2.61 mm Hg in the control group, (P< .001). Mean arterial carbon dioxide was 46.90 +/- 6.55 and 31.42 +/- 4.87 mm Hg, respectively. Surgeons blinded to the technique assessed the descent of the tumor. The operating conditions were judged by the surgeons to be satisfactory for 20 patients in the study group and 17 patients in the control group. Both techniques were equally effective in raising intracranial pressure and in providing descent of the suprasellar component of the tumor. No untoward side effects occurred while using either technique. The authors conclude that controlled hypercapnia is effective in producing descent of the suprasellar portion of a pituitary adenoma.

A novel thermostable xylanase from Thermomonospora sp.: influence of additives on thermostability.

An alkalothermophilic Thermomonospora sp. producing high levels of xylanase was isolated from self-heating compost. The culture produced 125 IU/ml of xylanase when grown in shake flasks at pH 9 and 50 degrees C for 96 h. The culture filtrate also contained cellulase (23 IU/ml), mannanase (1 IU/ml) and beta-xylosidase (0.1 IU/ml) activities. The xylanase was active at a broad range of pH (5-9) and temperature (40-90 degrees C). The optimum pH and temperature were 7 and 70 degrees C, respectively. The enzyme was stable in the pH range 5-8 and was thermostable with half-lives of 8 and 4 h at 60 degrees C and 70 degrees C, respectively, but only 9 min at 80 degrees C. The effects of a variety of compounds to enhance the stability of xylanase at 80 degrees C was studied. Addition of sorbitol, mannitol and glycerol increased the thermostability of xylanase in proportion to the number of hydroxyl groups per polyol molecule. Glycine also offered protection against thermoinactivation. Xylan, trehalose, gelatin and trehalose-gelatin mixture had marginal effect on the thermostability of xylanase at 80 degrees C.

Conformation and polarity of the active site of xylanase I from Thermomonospora sp. as deduced by fluorescent chemoaffinity labeling. Site and significance of a histidine residue.

A fluorescent chemoaffinity label o-phthalaldehyde (OPTA) was used to ascertain the conformational flexibility and polarity at the active site of xylanase I (Xyl I). The kinetics of inactivation of Xyl I with OPTA revealed that complete inactivation occurred due to the binding of one molecule of OPTA to the active site of Xyl I. The formation of a single fluorescent isoindole derivative corroborated these findings. OPTA has been known to form a fluorescent isoindole derivative by crosslinking the proximal thiol and amino groups of cysteine and lysine. The involvement of cysteine in the formation of a Xyl I-isoindole derivative has been negated by fluorometric and chemical modification studies on Xyl I with group-specific reagents and by amino-acid analysis. The kinetic analysis of diethylpyrocarbonate-modified Xyl I established the presence of an essential histidine at or near the catalytic site of Xyl I. Modification of histidine and lysine residues by diethylpyrocarbonate and 2,4,6-trinitrobenzenesulfonic acid, respectively, abolished the ability of the enzyme to form an isoindole derivative with OPTA, indicating that histidine and lysine participate in the formation of the isoindole complex. A mechanism for the reaction of OPTA with histidine and lysine residues present in the protein structure has been proposed. Experimental evidence presented here suggests for the first time that the active site of Xyl I is conformationally more flexible and more easily perturbed in the presence of denaturants than the molecule as a whole. The changes in the fluorescence emission maxima of a model compound (isoindole adduct) in solvents of different polarity were compared with the fluorescence behaviour of the Xyl I-isoindole derivative, leading to the conclusion that the active site is located in a microenvironment of low polarity.

Involvement of a lysine residue in the active site of a thermostable xylanase from Thermomonospora sp.

A highly thermostable xylanase (Xyl I) produced by Thermomonospora sp. was purified to homogeneity and was classified as a family 10 xylanase based on its molecular weight (38,000 Da) and isoelectric point (4.1). K2d analysis showed that the secondary structure of Xyl I was made up of 38% alpha-helix and 10% beta-sheet. The optimal temperature for the activity of Xyl I was 80 degrees C. Xyl I was highly thermostable with half-lives of 86, 30, and 15 min at 80, 90, and 100 degrees C respectively. Xyl I was stable in an expansive pH range of 5 to 10 with more than 75% residual activity. Our present investigation using o-phthalaldehyde (OPTA) as the chemical initiator for fluorescent chemoaffinity labeling and trinitrobenzenesulphonic acid (TNBS) as chemical modifier have revealed the presence of a single lysine residue in the active site of Xyl I. The high pK value for the basic limb of the pH profile reflects the ionization of a lysine residue. The higher K(m) values and similar k(cat) values of the TNBS modified enzyme in comparison to native enzyme and the substrate protection against OPTA and TNBS, suggested the presence of the lysine residue in the substrate-binding site.

Studies on carboxymethyl cellulase produced by an alkalothermophilic actinomycete.

A novel alkalothermophilic actinomycete having optimum growth at pH 9 and 50 degrees C was isolated from self-heating compost from the Barabanki district of Uttar Pradesh, India. Based on its morphology, susceptibility of spores to heat and novobiocin, guaninecytosine content of chromosomal DNA and cell wall composition, the organism was classified under Thermomonospora. The alkalothermophilic actinomycete produced 23 IU/ml carboxymethyl cellulase (CMCase). The CMCase was purified by fractional ammonium sulphate precipitation followed by cellulose affinity chromatography and Sephacryl S-200 gel filtration. The CMCase had a molecular weight of 38 KD and pI of 4.1. The enzyme exhibited optimum activity at pH 5 and temperature 50 degrees C. The CMCase showed pH stability in the range 7-10. The enzyme retained 100% activity at 50 degrees C for 72 h and had half-lives of 7 and 3 h at 60 degrees C and 70 degrees C, respectively. The CMCase was stable in the presence of commercial detergents such as Ariel, Henko and Surf Excel, indicating its potential as an additive to laundry detergents.

Photorefractive keratectomy retreatments: comparison of two methods of excimer laser epithelium removal.

BACKGROUND: Regression and undertreatment after initial photorefractive keratectomy (PRK) in higher myopes is not unusual. Patients frequently desire 20/20 uncorrected vision, which necessitates retreatments or enhancements. However, the safest and most efficacious way to treat these patients has not yet been established. This study evaluates two techniques of PRK enhancements, comparing two different methods of laser epithelial removal. DESIGN: Retrospective, nonrandomized, comparative trial. PARTICIPANTS: A total of 224 eyes. METHODS: Eyes were identified that had 6-month follow-up after a PRK enhancement from February 1995 through February 1997. Two methods of treatment were identified. The same VISX 20/20B laser in the same clinic was used for all retreatments. Group I patients had a total removal of the epithelium in a mode phototherapeutic keratectomy (PTK) prior to the refractive ablation. Group II patients had a total laser epithelial removal in two steps prior to the refractive ablation. The first step was a PRK and then a PTK. MAIN OUTCOME MEASURE: The disappearance of epithelial fluorescence was the end point for the PTK ablation in groups I and II. RESULTS: There were 131 eyes in group I and 93 eyes in group II. The mean spherical equivalent (SE) prior to the original PRK in group I was -7.5 diopters (D) +/- 3 D and in group II was -7.75 D +/- 2.34 D. The mean SE prior to the PRK retreatment in group I was -2.22 D +/- 1.29 D and in group II was -1.89 D +/- 0.83 D. The mean postoperative 6-month SE after the PRK enhancement in group I was -0.05 D +/- 0.80 D and in group II was 0.01 D +/- 1.08 D. A greater proportion of group I eyes (7.8%) had arcuate haze and a hyperopic shift from the 1- to 6-month postoperative visit (P = 0.03). CONCLUSIONS: A two-step laser epithelial removal compared with a one-step PTK epithelial laser removal in PRK retreatments provides a more even and confluent epithelial removal, less risk of arcuate haze development, and less risk of a hyperopic shift from 1 to 6 months after the retreatment.

Removal of corneal epithelium with phototherapeutic technique during multizone, multipass photorefractive keratectomy.

BACKGROUND: The therapeutic mode of the VISX 20/20 excimer laser was used to remove the corneal epithelium prior to performing photorefractive keratectomy (PRK) with a multizone, multipass technique. METHODS: A retrospective analysis was performed of 120 eyes of 90 patients that were treated for preoperative spherical refractive errors from -1.00 to -7.00 diopters (D) (mean -3.90 D, SD 1.54) by one surgeon (DGJ) over 7 months. RESULTS: Six-month follow-up was obtained in 76 eyes (63%). Sixty-nine eyes (91%) achieved a spherical equivalent refraction within +/-1.00 D of emmetropia. Regression of effect averaged -0.35 D (SD 0.53 D) from 1 to 6 months after surgery. Mean postoperative uncorrected visual acuity at 6 months was 20/25 (range 20/15 to 20/200). Seventy-three eyes (96%) achieved uncorrected visual acuity of 20/40 or better, 67 (88%) achieved uncorrected visual acuity of 20/25 or better, and 76 (71%) achieved 20/20 or better. Three eyes (4%) lost one line of spectacle-corrected visual acuity; no eye lost more than one line. There were no significant surgical complications. CONCLUSION: Removal of corneal epithelium with the Summit Excimed UV 200 LA excimer laser using multizone, multipass photoablation yields visual and refractive results that compare favorably with published PRK series with excellent short-term stability.

Other uses of tube changer.

Traditionally major surgical procedures are contemplated in tracheobronchial pathology as the first line of management. Efficient and skillful use of airway equipment can help in the management and prevention of significant perioperative morbidity. Three cases of airway pathology (tracheal stenosis, bronchial stenosis and tracheal tumour) which were managed with the help of airway equipment such as fibreoptic bronchoscope, Cook's and Patil tube changers are presented. The techniques are simple and safe and may help the surgeons to 'buy' time to plan definitive treatment.

Dermochondral corneal dystrophy (of François).

Dermochondral corneal dystrophy (of François) has been reported rarely in the literature. It consists of a triad of findings characterised by the development of skin nodules, acquired deformities of the extremities, and a corneal dystrophy. The corneal dystrophy is central and superficial with whitish subepithelial opacities. We present two brothers who display previously unreported ocular findings. Specifically, they developed confluent opacification of their central corneas with anterior stromal involvement, and peculiar anterior cortical cataracts. These findings should be added to the spectrum of findings seen in this rare disorder.

Flow cytometric monitoring of human immunodeficiency virus-infected patients. Simultaneous enumeration of five lymphocyte subsets.

The utility of CD4 lymphocytes in monitoring disease progression and prognosis of human immunodeficiency virus (HIV)-infected patients is well established. We have modified a previously described antibody cocktail to provide complete lymphocyte subset analysis on 100-200-microL samples of whole blood. This method optimizes accuracy of CD4 lymphocyte assessments and provides simultaneous assessment of four other lymphocyte subtypes of interest in specimens with absolute lymphocyte counts as low as 300 X 10(6)/L. Lymphocytes are classified as Thelper (CD3+CD4+); Tsuppressor (CD3+CD8+); Tnull (CD3+CD4-CD8-, putative gamma delta T-cell receptor); B (CD19+CD20+); or natural killer (CD3-CD16+CD56+). The method positively discriminates against contamination of lymphocyte scatter gates by monocytes and unlysed erythrocytes and is compatible with a variety of cell preparation procedures. Increased accuracy of CD4 lymphocyte determinations and simultaneous identification of other lymphocyte subsets whose relationship to disease progression is under study make this an efficient and informative method for disease monitoring and evaluation of therapy in HIV-infected patients.