Solution thermodynamics and solubilization behavior of diclofenac sodium in binary mixture of Transcutol-HP and water

Solution thermodynamics and solubilization behavior of diclofenac sodium (DS) in binary mixture of Transcutol-HP and water is not reported in the literature so far. Therefore, the aim of the present study was to investigate the solution thermodynamics and solubilization behavior of DS in mono-solvents and various Transcutol-water mixtures at 298.15-333.15 K. The mole fraction solubility of DS was determined by shake flask method and thermodynamic parameters (enthalpies and entropies) were calculated with the help of the modified Apelblat model. The experimental solubility data of DS in all sample matrices was found to be correlated well with the modified Apelblat model with correlation coefficients of 0.9950-0.9990. Absolute relative deviation was found to be less than 3% in most of the Transcutol-water mixtures at each temperature studied. The mole fraction solubility of DS was observed to be highest in pure Transcutol (0.139 at 298.15 K) as compared to pure water and other Transcutol-water mixtures. The enthalpies and entropies for DS dissolution were observed as positive values for all cosolvent mixtures which indicated that the dissolution of DS is endothermic and an entropy-driven process. Based on solubility data, DS was considered as sparingly soluble in pure water and freely soluble in Transcutol. These results indicated that Transcutol could be used as an alternate of ethanol, propylene glycol and polyethylene glycol to enhance aqueous solubility of DS. These preliminary studies could be useful in formulation development of DS especially in terms of liquid dosage forms and injectable formulations.

Synergistic Effect of Cationic-Nonionic Surfactants on Simultaneous Separation of Phenylalanine and Tyrosine

A new thin layer chromatographic system comprising of silica gel impregnated with 0.1% aqueous solution (below CMC) of nonionic surfactant Brij-35 as stationary phase and 0.1% aqueous solution (below CMC) of cationic surfactant (cetrimide) as eluent has been found most suitable for the separation of closely related amino acids (phenylalanine and tyrosine) from their mixture. Effect of substitution of Brij-35 by cetrimide and sodium cholate has been examined to assess the impact of charge of impregnant on the chromatographic behavior of analytes. The changes brought about by the impregnation in the structure and homogeneity of silica gel have been studied by scanning electron microscopy (SEM) and fourier transform infra-red spectroscopy (FTIR) techniques. Optimizations of concentration of Brij-35 and cetrimide in the stationary and mobile phases respectively and the effect of bed height on the separation have also been examined. Chromatographic parameters like ΔRF, separation factor (α) and resolution (RS) were calculated for the separation of tyrosine from phenylalanine and separation mechanism have been proposed. The limits of detection for phenylalanine and tyrosine were found to be 0.25 and 0.23 μg respectively. The proposed method studied is simple, rapid and free from the use of volatile organic solvents.

Stressful life events, personal losses, and perimenopause-related depression

We compared the number and quality of life events reported by depressed perimenopausal women and a non-depressed comparison group. Additionally, we examined the effects of the presence of hot flushes on life event reports. All women were 44-55 years old, had irregular menses and elevated plasma gonadotropin levels. The Psychiatric Epidemiology Research Interview recorded both the frequency of occurrence and the desirability of life events experienced by the women during the six months prior to the interview. Depressed perimenopausal women (n=50) reported significantly more undesirable events [Student's t-test (unpaired) with Bonferroni correction, t(98)=3.9, p=0.001] but not more exit events (e.g., divorce, last child leaving home or death in family) (t(98)=0.9, p=NS) compared to the non-depressed women (n=50). There were no effects of hot flushes on these diagnostic differences. The "empty nest" syndrome does not appear to be relevant in the development of perimenopausal depression. Nevertheless, independent of the presence of hot flushes, perimenopausal depressed women are more likely to report both negative life events and diminished self esteem.

Evaluation of hospitalized infants and young children with bronchiolitis - a multi centre study

Four hundred and twenty nine young children with bronchiolitis admitted consecutively in different hospitals of Bangladesh were evaluated. Three hundred and forty eight children studied for their putative risk factors, clinical profile, management and the outcome. Both cases and controls were examined for respiratory syncytial virus (RSV) antibody status. The diagnosis of bronchiolitis was made on the basis of first attack of wheeze in previously healthy children below two years of age. Detailed history including the possible risk factors, the management and daily follow-up on the ward and the outcome at discharge were documented through a structured questionnaire. Chest x-ray was done in each case to find out the radiological changes. Blood of 266 patients and 30 controls were studied for RSV IgM and IgG antibody by ELISA. There were 66% male and 34% female children. The median age of the children was 3.0 months and 82.7% were below 6 months of age. Most of the babies were born term (88%), with ABW (73%), by normal vaginal delivery (88%). Exclusive or predominant breast-feeding were given in 72% cases. The location of the patient was rural in 55% cases. Around half of the parents were illiterate or slightly educated (up to 5 years schooling) fathers 46.5% and mothers 56% and majority of the parents were poor (74%). In 52% cases the number of family members in one room were four or more. Half of the parents (52%) were smokes and there was atopy in 26.5% families. The clinical features of bronchiolitis were mostly cough (99%), respiratory distress (97%), feeding difficulty (93%) and fast breathing (96%) (median RR 68/min). Fever (1000F or more) was in only 33% cases, though parents complained in 90% cases. All children (100%) had wheeze and crackles in lungs in 96% cases. Liver could be palpable in 83% and spleen in 42% cases. Important radiological features were increased translucency (96%), increased interstitial markings (87%), hyperinflation (75%) and streaky densities (61%). In 69.6% cases TLC was 12,000 or less and only 15% with a neutrophil fraction greater than 60%. Children were positive for IgM antibody in 43.6% cases and both IgM and IgG in 5.3% cases. The main modalities of treatment were antibiotics (99%) (Ampicillin, 76%), oxygen therapy (83%), nebulised salbutamol (76%) and intravenous fluid (51%). The median duration of hospital stay was 4 days. Most of the children were discharged with improvement (96%) with 2% mortality. Not a single case was diagnosed as bronchiolitis in hospitals outside Dhaka. Cefrtiaxone (72.5%) and parenteral steroids (70.5%) were the mainstay of therapy there.

Brain dysfunction following 'awake' craniotomy, brain mapping and resection of glioma

The rationale for 'awake' resective brain tumour surgery and brain mapping is that the amount of tumour removed is optimized, and risks of damage to adjacent eloquent brain minimized by intraoperative patient assessments. Both goals are generally attained, but occasionally patients may have iatrogenic postoperative deficits. Five such cases (20%) are described from a consecutive series of 25 awake craniotomies. These patient fell into three distinct clinical categories; those (n = 2) who developed sensory-motor deficits that were recognized intraoperatively; those (n = 2) who had deficits that were apparent only on postoperative testing; and one patient who developed a sudden deficit with no warning. The former four patients had deficits that recovered within weeks to months (16%), but the latter one (4%) was left with a severe focal motor disability. These cases highlight both the benefits and limitations of awake craniotomy and intraoperative assessment. Although sensory-motor deficits can be recognized early, some high-level neurological functions may not be readily assessed intraoperatively and vascular catastrophes may occur without warning. The pathophysiological basis of these iatrogenic neurological deficits, and techniques to minimize such problems are discussed.

Basal plasma hormone levels in depressed perimenopausal women

BACKGROUND

An association between abnormal changes in reproductive endocrine function during the perimenopause and the onset of depression in some women has been suggested but remains controversial.

METHODS

We examined basal plasma hormone levels in two samples of women with well characterized, first onset depression (major or minor) during the perimenopause and matched comparison groups of asymptomatic women. Results were compared by analysis of variance.

RESULTS

No significant diagnosis-related differences were observed in plasma hormone measures of the following: follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), estrone (E1), total (T) or free testosterone (FT), or the E2/LH ratio. We did identify significantly lower morning plasma dehydroepiandrosterone (DHEA) and its sulphated metabolite DHEA-S (but not cortisol) levels in the depressed women compared to the non-depressed comparison group. Women with hot flushes (regardless of the presence of depression) were significantly older than women without flushes, had significantly higher plasma levels of FT, LH and FSH, and had significantly lower E2/LH ratios.

CONCLUSIONS

Women with first onset depression during the perimenopause are not distinguished from controls on the basis of basal hormone measures of ovarian estrogens, testosterone, or gonadotropins. However, perimenopause-related changes in E2 may interact with low levels of DHEA in some women to increase their vulnerability to develop depression. In contrast to perimenopause-related vasomotor symptoms, depression during the perimenopause is not associated with a simple hormone deficiency state. The relatively low levels of E2 and E1 in the depressed women may have met statistical significance in a much larger and homogenous sample.

Correlation of MRI lesions with visual psychophysical deficit in secondary progressive multiple sclerosis

The aim of this work was, first, to clarify the nature of the relationship between the sensory deficit in the demyelinated visual pathway and morphological changes revealed by MRI and, secondly, to test whether there was a preferential effect of demyelination for either the magnocellular or parvocellular pathway in established multiple sclerosis. Twenty-four patients with secondary progressive multiple sclerosis were studied psychophysically and by MRI of the optic nerve and brain. MRI was performed with a Phillips (0.5T) scanner. Visual pathway MRI lesion load was evaluated independently using the total optic nerve lesion length and lesion area seen on STIR (short inversion time inversion recovery) images of the optic nerve and the total post-chiasmal lesion area on T(1)-, T(2)- and proton-density-weighted images of the brain. Psychophysical tests determined 75%-seeing thresholds for horizontal gratings consisting of isoluminant red and green sinusoids of the same spatial frequency combined out-of-phase for preferential stimulation of the parvocellular system and in-phase for preferential stimulation of the magnocellular system. It was found that, in this group of patients, visual psychophysical loss was significantly correlated with lesion area seen on proton density MRI sequences of the post-chiasmal visual pathway, and that the parvocellular pathway was more affected than the magnocellular pathway, especially at lower spatial frequencies.

MRI of optic nerve and postchiasmal visual pathways and visual evoked potentials in secondary progressive multiple sclerosis

We studied the relationship between abnormalities shown by MRI and functional disturbances in the visual pathway as assessed by the visual evoked potential (VEP) in 25 patients with established multiple sclerosis (MS); only 4 of whom had a history of acute optic neuritis. Optic nerve MRI was abnormal in 19 (76%) and is thus useful in detecting subclinical disease. Optic nerve total lesion length and area on the STIR sequence was found to correlate significantly with prolongation of the VEP latency. This may reflect a predominantly demyelinating rather than inflammatory origin for the signal change in the optic nerve.

Cortical plaques visualised by fluid-attenuated inversion recovery imaging in relapsing multiple sclerosis

Fluid-attenuated inversion recovery (FLAIR) imaging with prolonged inversion times allows generation of highly T2-weighted images of the brain with suppression of cerebrospinal fluid signal. Such sequences result in high lesion contrast and allow visualisation of abnormalities not seen with conventional T2-weighted spin-echo sequences. We used FLAIR sequences, proton density (PD) and standard T2-weighted images to examine lesion number and distribution in ten patients with clinically definite relapsing multiple sclerosis (MS). We also studied the extent and distribution of blood-brain-barrier breakdown by gadolinium-enhanced T1-weighted images. FLAIR sequences proved feasible both in terms of acquisition time and image quality using a 0.5 T imager. FLAIR imaging allowed identification of 45% more high-signal lesions than T2-weighted or PD images in the 10 patients. In particular, 60% more lesions within the cortex and at the grey-white interface were identified. Cortical lesions, none of which enhanced following gadolinium-DTPA injection, were present in seven of the ten patients studied. Of all lesions identified, 8% were cortical. FLAIR sequences are more sensitive to cortical and subcortical lesions in patients with active demyelination.

Peripartum hypopituitarism and lymphocytic hypophysitis

The classical cause of postpartum hypopituitarism is Sheehan's syndrome, in which an obstetric catastrophe is associated with hypotension. However, with improvements in obstetric care, the most common cause now may be lymphocytic hypophysitis. Five women with postpartum hypopituitarism, whose symptoms occurred during or immediately after pregnancy, had detailed endocrine and pituitary imaging for the duration of follow-up. Two presented with visual symptoms, and three with non-specific illnesses related to varying deficiencies of anterior pituitary hormones. Four were unable to lactate, and four were initially amenorrhoeic. Initially, four of the five women had enlarged pituitary glands on magnetic resonance imaging. Four have to some extent recovered pituitary function. One patient had associated thyroiditis: in two cases antinuclear antibodies became positive during follow-up, and in one of these dsDNA antibody was also detected. In no case were pituitary antibodies detected. None had complicated pregnancies or deliveries, and the two who had caesarean sections had no episodes of hypotension. The presentation of secondary hypothyroidism combined with ACTH deficiency in four of the five women strongly suggests lymphocytic hypophysitis. This diagnosis should be considered in postpartum women with general malaise and persistent amenorrhoea, as well as in women who develop visual impairment in the last trimester of pregnancy without antecedent pituitary disease. A conservative policy of management of the pituitary enlargement should be pursued as this resolves.

High speed rotational coronary atherectomy for patients with diffuse coronary artery disease

High speed rotational coronary atherectomy was undertaken using the Rotablator in 42 patients who were suboptimal candidates for balloon angioplasty. Most patients (71%) had diffuse coronary artery disease, defined as a stenosis greater than 1 cm in length. Previous restenosis after balloon angioplasty was present in 21% and 10% had an ostial lesion. Adjunctive balloon angioplasty was not used to reduce residual stenosis after atherectomy. The procedure was successful in 76% of patients. Procedural success was achieved in 92% of patients with a lesion less than or equal to 1 cm in length, but in only 70% of patients with a lesion greater than 1 cm in length (p less than 0.01). One patient sustained abrupt closure of the target vessel, resulting in emergency bypass surgery and death. Small non-Q wave myocardial infarction occurred in eight patients (19%) and was associated with a longer lesion. The mean peak creatine kinase value in patients with non-Q wave myocardial infarction was 683 U/liter. Transient regional wall motion abnormalities were noted on the postatherectomy left ventricular angiogram in four of the eight patients with non-Q wave myocardial infarction. Follow-up angiography (at a mean interval of 6.2 +/- 2.6 months) was performed in 91% of patients and revealed restenosis (greater than 50% narrowing) in 59% The resistance rate was 22% for short lesions (less than or equal to 1 cm) and 75% for long lesions (greater than 1 cm) (p less than 0.05). In this study, the results of high speed rotational coronary atherectomy were strongly influenced by lesion length.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral arteritis with unusual distribution

Giant cell arteritis (GCA), especially its cerebral manifestation, is probably underdiagnosed. Very few lesions affecting the carotid siphon have been reported but no reference can be found to the disease involving the anterior or posterior cerebral arteries. In the case presented here, anterior and posterior cerebral arteries were involved, as well as both carotid siphons; and angiography was an important ingredient of the diagnosis. The differential diagnosis is discussed, and a review of the literature is presented which uncovered several misconceptions regarding the diagnosis of GCA. The importance is stressed of recognising this life-threatening condition, which can be effectively controlled with steroids. The radiologist can be the first person to raise the alarm.

Plant protoplast enucleation by density gradient centrifugation

A number of different methods have been developed for the enucleation of cells, particularly mammalian cells. Centrifugation of cells adhering to a surface may lead to the nucleus being drawn out from the cytoplasm, resulting in the formation of an enucleated cell or cytoplast and a nucleus surrounded by a thin layer of cytoplasm bounded by a plasma membrane (mini-cell). In those cases where cells do not adhere sufficiently firmly to a surface, enucleation has been achieved by centrifugation in density gradients. This method takes advantage of the differing densities of the nucleus and the cytoplasm. When cells are centrifuged at high speed in a suitable density gradient, the nucleus and the cytoplasm tend to float in those regions of the gradient matching their own densities. If the distance between the regions with densities corresponding to that of the cytoplasm and that of the nucleus is relatively long, considerable stretching forces are generated. Under optimum conditions, this force is usually sufficient to enucleate a high percentage of the cells. The use of density gradients and high-speed centrifugation for generating cytoplasts and mini-cells is much less explored in plant than in mammalian cells.

Percutaneous transhepatic internal drainage using polyurethane double-pigtail endoprostheses

Relief of obstructive jaundice by the percutaneous transhepatic insertion of an endoprosthesis is now a well recognised and common radiological procedure. We report the successful insertion of polyurethane double-pigtail stents (made for transpapillary endoscopic insertion) by the percutaneous transhepatic route in five patients. Our experience indicates that these stents are as effective in relieving jaundice as, and less traumatic and easier to insert than, the larger varieties in common use.