Middle meningeal arteriovenous fistula and its spontaneous closure. A case report and review of the literature

SUMMARY

Middle meningeal artery pseudo-aneurysms and arteriovenous fistulas are usually post-traumatic, although occasional iatrogenic cases have been reported. The treatment has been obliteration of the fistula by surgical or endovascular means. Spontaneous closure of fistula is uncommon. We report a case of non-traumatic middle meningeal arteriovenous fistula in a patient with alcoholism, which resolved spontaneously without treatment.

Clinicoradiological features of tuberculous meningitis in patients over 50 years of age

BACKGROUND AND AIMS

Tuberculous meningitis (TBM) is a debilitating form of CNS tuberculosis with a high morbidity and mortality in spite of treatment. The diagnosis is based on clinical, radiological and laboratory features. The classical CT features of basal exudates, hydrocephalus, infarcts and granulomas have been mostly reported in younger individuals. Our aim was to study imaging features of TB meningitis in adults over the age of 50 years.

MATERIALS AND METHODS

Clinical, imaging and laboratory features of 53 adult patients over the age of 50 years (sixth to eighth decades) were studied retrospectively. Diagnosis of TBM was based on clinical and laboratory features.

RESULTS

Imaging features were the conspicuous absence of typical features of TBM (ie, basal meningeal enhancement, hydrocephalus, infarcts/granulomas were seen in only a minority of patients).

CONCLUSIONS

CT features of TBM in elderly patients were few, atypical and non-contributory for diagnosis, probably because of age related immune senescence. Strong clinical suspicion and correlation with laboratory findings is necessary for early diagnosis.

Restricted diffusion in Canavan disease

INTRODUCTION

Canavan disease is a megalencephalic leukodystrophy due to deficiency of the enzyme aspartoacylase. Proton MR spectroscopy finding of elevated N-acetyl-L: -aspartate is considered diagnostic of Canavan disease.

CASE REPORT

We report a case of Canavan disease, which showed restricted diffusion in diffusion-weighted imaging and discuss the cause of it.

Quantitative magnetic resonance techniques in the evaluation of intracranial tuberculomas

PURPOSE

To evaluate intracranial tuberculomas using quantitative magnetic resonance (MR) techniques such as T2 relaxometry, magnetization transfer (MT), and diffusion-weighted imaging (DWI).

MATERIAL AND METHODS

Thirty-three patients with intracranial tuberculomas (histologically confirmed in 22) were evaluated using proton density/T2-weighted, T1-weighted (with and without MT), and echo-planar diffusion-weighted imaging sequences. T2 relaxation times, MT ratios (MTR), and apparent diffusion coefficient (ADC) values were calculated from the center of the lesion, the periphery, perilesional edema, and contralateral normal white matter. The mean and standard deviation values of each variable were calculated and correlated using Pearson's test (P = 0.05).

RESULTS

The measured mean values of T2 relaxation time, MTR, and ADC in the center of lesions were 155.5 ms, 14.1, and 1.27 x 10(-3) mm(2)/s, respectively, compared to 117 ms, 23.72, and 0.74 x 10(-3) mm(2)/s in normal white matter, and a T2 relaxation time of 187.45 ms in normal gray matter. Significant inverse correlations were noted between T2 relaxation values and MTR (P<0.001) and between MTR and ADC (P = 0.046). Significant positive correlation was seen between T2 relaxation and ADC values (P = 0.03).

CONCLUSION

Intracranial tuberculomas are characterized by relatively short T2 relaxation times (compared to normal gray matter), decreased MTR, and mostly no restriction of diffusion. A combination of these quantitative parameters could be of help in the noninvasive diagnosis of tuberculomas.

Unilateral Moyamoya Phenomenon Due to MCA Occlusion in a Child Presenting with Intracerebral Hemorrhage

SUMMARY

Spontaneous middle cerebral artery (MCA) occlusion leading to moyamoya phenomenon is different from classical moyamoya disease. Previous studies have reported such phenomena in adults with ischemic lesions, except for a solitary case in a child.We report a case of a ten-year old girl who presented with a deep intracerebral hematoma and a normal ipsilateral middle cerebral artery on initial evaluation by CT. Subsequently, on follow-up angiography, the ipsilateral MCA was occluded with evidence of unilateral basal lenticulostriate and transdural collateral supply causing a 'moyamoya' phenomenon. This report discusses a rare and interesting disease from the perspective of 'moyamoya' phenomenon and angiogenesis.

Multi-slice computed tomography appearance of abscess of cavum septum pellucidum: a case report and review of the literature

Abscesses involving the cavum septum pellucidum are rare and, owing to their location, detection may be difficult with routine conventional computed tomography (CT). Only a few isolated cases have been reported and mostly in children. We report a case of abscess involving the cavum septum pellucidum in an adult and its appearance on multi-slice spiral CT.

Comparative anti - microbial evaluation studies of the extracts and isolates of leaves & bark of wrightia tomentosa

The Butanol and Ethanol extract of the leaves and bark of Wrightia tomentosa along with its seven pure component isolates (BLF(28), BLF(29*), BBF(29), ELF(3), ELF7, ELF(17*), EBF(7) ) after fractionation by column chromatography were evaluated for antimicrobial activity against Gram positive (S. aureus, S. fecalis, S.albus and B.subtilis) and Gram negative (Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris & Klebsiella aerogenes) bacteria and the fungi Candida albicans by disc diffusion method. The extracts and isolates showed different degree of activity against pathogenic microbes. The results obtained were compared with standard drugs Ciprofloxacin (10μg) and Clotrimazole (10μg). The isolates of butanol bark extract (BBF(29)) followed by leaf extract(BLF(29*)) were considerably more effective than the ethanol leaf and bark extract in inhibiting all the microbial strains.

Crystal engineeringviaC—H...F and C—H...π interactions in two substituted indoles

The crystal structures of 1-(4-fluorophenyl)-2-phenyl-4,5,6,7-tetrahydro-1H-indole, C20H18FN, and 1-(4-fluorophenyl)-6,6-dimethyl-2-phenyl-4,5,6,7-tetrahydro-1H-indole, C22H22FN, have been determined in order to study the role of 'organic fluorine' in crystal engineering. These molecules pack in the crystal structure via different types of molecular motifs utilizing weak C-H...F and C-H...pi interactions.

An analysis of C—H...O and C—H...π interactions in three substituted 4-ketotetrahydroindoles

The crystal and molecular structures of the three 4-ketotetrahydroindoles 2-(4-chlorophenyl)-1-(4-fluorophenyl)-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indol-4-one (C22H19ClFNO), (I), 1-(4-fluorophenyl)-2-(4-methoxyphenyl)-6,6-dimethyl-4,5,6,7-tetrahydro-1H-indol-4-one (C23H22FNO2), (II), and 6,6-dimethyl-1,2-diphenyl-4,5,6,7-tetrahydro-1H-indol-4-one (C22H21NO), (III), have been determined via single-crystal X-ray diffraction in order to study the intermolecular interactions therein. All three structures are stabilized via intermolecular C-H...O and C-H...pi interactions, generating different molecular motifs.

An ultralight biotelemetry backpack for recording EMG signals in moths

A two-channel FM biopotential recording system fabricated on a foldable, lightweight, polyimide substrate is presented. Each channel consists of a biopotential amplifier followed by a Colpitts oscillator with operating frequency tunable in the 88-108 MHz commercial FM band. The overall system measures 10 mm X 10 mm X 3 mm, weighs 0.74 g, uses two 1.5-V batteries, dissipates about 2 mW, and has a transmission range of 2 m. Using this system, electromyogram signals have been recorded from the dorsal ventral muscle and the dorsal longitudinal muscle of a giant sphinx moth (manduca sexta).

Oxoanionic or sulfur lone pair attack? The difference in reactivity of hydrogensulfite anion and neutral dimethylsulfite towards [Bu4N]2[MoO2{S2C2(CN)2}2] in the model reductive half reaction of sulfite oxidase

pH dependent reactivity differences of dimethylsulfite towards the title complex 1 demonstrate the crucial need of oxo-anionic coordination of sulfite to the molybdenum centre of 1 in the model reductive half reaction of sulfite oxidase.

1-Isobutyl-2,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydro-3-indoleacetic acid

The title compound (C17H25NO3) is a perhydroindoleacetic acid which exhibits hypoglycemic activity. The cyclohexyl ring adopts a sofa conformation. The molecule contains an intramolecular O-H...O hydrogen bond.

Structural basis for selective inhibition of COX-2 by nimesulide

Nimesulide 1 is a novel nonsteroidal antiinflammatory drug which inhibits the enzyme cyclooxygenase 2 (COX-2) more selectively than cyclooxygenase 1 (COX-1). Molecular modelling studies have been carried out on complexes of 1 with COX-1 and with mutants of COX-1 simulating COX-2. These indicate that the mutations I523V and S516A largely contribute to the selectivity. A comparative study with SC-558 2 has also been performed.

Peribulbar anesthesia for primary vitreoretinal surgery

We prospectively studied the efficacy of peribulbar anesthesia in 76 consecutive patients who underwent vitreoretinal surgery. The mean duration of anesthesia was 124.74 +/- 50.17 minutes, and the mean duration of akinesia, 151.5 +/- 54.45 minutes. Adequate anesthesia and akinesia, independent of the duration of surgery, was obtained in 26 of 33 (78.8%) patients who underwent vitrectomy; 9 of 32 (28.1%) who underwent scleral buckling; and 2 of 11 (18.2%) who underwent vitrectomy combined with scleral buckling. In all, topical and systemic supplementation of drugs for inadequate anesthesia or akinesia allowed 32 of the 33 (97%) vitrectomies, 30 of the 32 (94%) scleral buckling procedures, and all 11 of the combined surgeries to be completed as planned. Three (4%) patients vomited, moved, or were restless, resulting in an operative complication or postponement of surgery. Fifty-eight (76%) said they would desire similar anesthesia if subsequent surgery was needed in the same or fellow eye. We conclude that peribulbar anesthesia should be considered primarily for patients requiring vitreous surgery alone, and as an alternative for patients requiring scleral buckling or combined surgery for whom general anesthesia is contraindicated.

Nitroimidazoles, Part XXIII--activity of satranidazole series against anaerobic infections

A large number of nitroimidazoles have been examined for in vitro activity against three anaerobes - Bacteroides fragilis (Bf), a strain of Bf resistant to metronidazole (16a) and Clostridium perfringens and many found to be active. Among these may be mentioned 1-methyl-5-nitroimidazoles carrying N - bound hetetocycles at position 2, such as satranidazole 1a, 1b, 1c, 1k, 1n and 1v which are at least twice as active as metronidazole (16a), ornidazole (16b) and tinidazole (16c). Even more active are 5-nitroimidazolyl benzimidazole 5d, -thiazolidinone 6b and thiadiazolidine dioxide 8a. Many other types of compounds derived from 1-methyl-2-amino-5-nitroimidazole are feebly active. Among 5-nitroimidazoles with a carbon substituent at position 2, 16a, 16b and 16c are equiactive while dimetridazole 14f is more active than 16a against Bf. Some 2-vinyl derivatives are very potent, with 18f and 18i being outstanding. Activity better than that of metronidazole is seen for nitroimidazooxazepines, e.g. 29d. 5-Nitroimidazoles are more active against anaerobes than 4-nitro isomers. Antianaerobic and antiamoebic activities generally run parallel in these classes of compounds. The study has led to the elaboration of the antianaerobic profile of satranidazole 1a.

General acid catalysis in the enolization of acetone

We have used iodometry to study the enolization of acetone in water catalyzed by a series of general acids, comprised of hydrochloric acid, methanesulfonic acid, 24 aliphatic monocarboxylic acids, nine aromatic monocarboxylic acids, eight aliphatic dicarboxylic acids, and 20 monoanions of dicarboxylic acids. The log k–pK profile for unbuffered solutions of strong and moderately strong acids shows a maximum near pk ≈ 0. The Brønsted α value for a set of eight aliphatic monocarboxylic acids in which effects of bulk, charge, and polarizability are at a minimum is 0.56. Steric effects, probably augmented by polarizability effects in some cases, cause positive deviations from the Brønsted line drawn with respect to these standard acids. Anionic carboxylic acids are also more reactive than would be predicted from their equilibrium acid strengths, whereas cationic acids tend to be less reactive. Using D2O as solvent has only a small effect on the rate of carboxylic acid catalysis. Using acetone-d6 gives values of kH/kD in the range of 7.0–8.0 at 25 °C, values consistent with proton or deuteron being transferred between two bases of comparable strength, the carboxylate anion and the enol form of acetone. Keywords: general acid catalysis, enolization, Brønsted relation, steric effects, deuterium isotope effects.

Synthesis and oral hypoglycemic properties of two 4-oxo-4,5,6,7-tetrahydroindole-3-acetic acids

Condensation of beta-acetyl-2-hydroxy-4,4-dimethyl-6-oxo-1-cyclohexene-1-propionic acid (3) with n-butyl and isobutylamines affords the title acids 4 and 5, respectively, which show good oral hypoglycemic activity in normal rats. Acids 4 and 5, are also active in streptozocin-induced diabetic rats. Results of extensive pharmacological and acute toxicity tests are reported.

Arylphosphonic acids. I. Substituent effects on their first and second dissociations

Thermodynamic pK1 and pK2 values of 36 arylphosphonic acids have been determined. The pK values of the meta and para compounds are correlated well by the σn parameter, suggesting that there is little conjugation between the phosphonic group and the aromatic ring; the ρ values of the first and second dissociations are 0.923 and 1.140, respectively. The —PO3H− group itself appears to be electron donating, contrary to earlier literature reports. The effect of ortho groups has been examined using multivariate analysis; the steric component of the proximity effect is acid weakening and has a larger effect on the second dissociation than on the first, presumably because a greater change in degree of solvation accompanies the second dissociation than the first.

Arylphosphonic acids. II. General acid and general base catalysis of acetone enolization

We have measured the rate constants for the enolization of acetone catalyzed by 29 arylphosphonate dianions (ArPO32−) and by 20 arylphosphonic acids (ArPO3H2). An excellent Brønsted correlation is found for the former reaction, with most ortho substituted compounds falling on the line drawn for the meta and para compounds (β = 0.72). The largest deviation is found for o-iodo, whose small positive deviation is ascribed to a polarizability effect in the transition state. The arylphosphonic acids give a fairly good Brønsted plot (α = 0.37) but here the ortho substituents tend to react slightly faster than would be expected on the basis of their equilibrium acid strengths. Catalysis by the monoanion ArPO3H− is difficult to detect; such ions appear to be acting as general acids, not general bases, and do not appear to act as bifunctional catalysts; it is shown that protonating acetone is 3.4 × 104 times as effective as deprotonating ArPO3H−. The Brønsted coefficients (β) for the rate-controlling steps for the enolization of acetone by the principal routes are shown to be inversely related to the magnitude of the rate constants.

Calcium uptake in frozen muscle biopsy sections compared with other predictors of malignant hyperthermia susceptibility

The frozen-section Ca45 uptake procedure of Mabuchi and Sreter has been applied to 51 frozen human muscle biopsies previously tested for halothane and for caffeine contracture responses. In preliminary tests with cat muscle, uptake varied with skeletal muscle fiber type, was absent from smooth muscle, and was blocked by agents which damage or extract sarcoplasmic reticulum. In the human biopsies, however, the calcium uptake values showed no significant correlation with any of the following parameters: time of frozen-biopsy storage up to 5 yr; fiber type distribution; positive versus negative response in the halothane contracture test; positive versus negative response in the caffeine contracture test; positive versus negative response in the combined halothane/caffeine contracture test; and presence of a documented clinical episode of malignant hyperthermia. In contrast, a positive halothane or caffeine contracture test each correlated highly with the presence of a prior clinical episode. We conclude that the evidence fails to support the use of the Ca45 uptake procedure in frozen sections of skeletal muscle biopsies as a valid indicator of malignant hyperthermia susceptibility.

Steric activation in prototropic reactions of pyrazine derivatives. II. The Brønsted relation

The rate of deprotonation of the 2-methyl group in 1,2,3-trimethylpyrazinium ion by carboxylate, aniline, and pyridine bases has been measured in D2O. Carboxylate ions containing bulky groups near the reaction centre, e.g. ortho benzoates, react faster than predicted by the Brønsted equation that correlates the reactions of unhindered carboxylates. Anilines and pyridines, on the other hand, show conventional steric effects. A tentative explanation for the activation engendered by groups adjacent to the carboxylate centre is based on the known effect that high concentrations of organic electrolytes have on the strengths of carboxylic acids but not of amines. Since ortho carboxylate ions have their relative basicities increased by an alkyl-rich environment, it is argued that the reactive methyl groups of the substrate might provide such an interaction in the transition state.