Radiation-induced brain disorders in patients with pituitary tumours

Radiation-induced brain disorders (RIBD) are uncommon and they are grave sequelae of conventional radiotherapy. In the present report, we describe the clinical spectrum of RIBD in 11 patients who received post-surgery conventional megavoltage irradiation for residual pituitary tumours. Of these 11 patients (nine men, two women), seven had been treated for non-functioning pituitary tumours and four for somatotropinomas. At the time of irradiation the age of these patients ranged from 30 to 59 years (mean, 39.4 +/- 8.3; median, 36) with a follow-up period of 6-96 months (mean, 18.3 +/- 26.4; median, 11). The dose of radiation ranged from 45 to 90 Gy (mean, 51.3 +/- 13.4; median, 45), which was given in 15-30 fractions (mean, 18.6 +/- 5.0; median, 15) with 2.8 +/- 0.3 Gy (median, 3) per fraction. The biological effective dose calculated for late complications in these patients ranged from 78.7 to 180 Gy (mean, 99.1 +/- 27.5; median, 90). The lag time between tumour irradiation and the onset of symptoms ranged from 6 to 168 months (mean, 46.3 +/- 57.0; median, 57). The clinical spectrum of RIBD included new-onset visual abnormalities in five, cerebral radionecrosis in the form of altered sensorium in four, generalized seizures in four, cognitive dysfunction in five, dementia in three and motor deficits in two patients. Magnetic resonance imaging (MRI)/CT of the brain was suggestive of radionecrosis in eight, cerebral oedema in three, cerebral atrophy in two and second neoplasia in one patient. Associated hormone deficiencies at presentation were hypogonadism in eight, hypoadrenalism in six, hypothyroidism in four and diabetes insipidus in one patient. Autopsy in two patients showed primitive neuroectodermal tumour (PNET) and brainstem radionecrosis in one, and a cystic lesion in the left frontal lobe following radionecrosis in the other. We conclude that RIBD have distinctive but varying clinical and radiological presentations. Diabetes insipidus and PNET as a second neoplastic disorder in adults following pituitary irradiation have not been reported previously.

Renal replacement therapy options from an Indian perspective: Dialysis versus transplantation

In developing countries such as India, the management of end-stage renal disease (ESRD) is largely guided by economic considerations. In the absence of health insurance plans, fewer than 10% of all patients receive renal replacement therapy (RRT). Hemodialysis (HD) is mainly a short-term measure to support ESRD patients prior to transplant. Infections are common in dialysis patients. The majority of patients starting HD die or are forced to abandon treatment because of cost constraints within the first 3 months. The cost of peritoneal dialysis (PD) is two times higher than that of HD, fewer than 2% of patients are started on PD. Among the three RRT options available, renal transplant is the preferred mode, as it is most cost-effective and provides a better quality of life. But due to financial constraints and nonavailability of organs, only about 5% of ESRD patients undergo transplant surgery. Though the removal of organs from brain-dead patients has been legalized, the concept of donation of organs from deceased donors has not received adequate social sanction. Only 2% of all transplants are performed from deceased donors. Due to limited access to RRT, the ideal approach should be to reduce the incidence of ESRD and attempt preventive measures. Preemptive transplant, reducing the duration of dialysis prior to transplant, use of immunosuppression for only up to 1 year, and availability of more deceased donor organs may be helpful to make RRT options within the reach of the common man.

A comparison of sonourethrography and retrograde urethrography in evaluation of anterior urethral strictures

AIM

This prospective study was undertaken to evaluate the abnormalities of the male anterior urethra using high-resolution ultrasound (sonourethrography) and to compare the efficacy with that of retrograde urethrography (RGU) using operative findings as the gold standard.

MATERIALS AND METHODS

Seventy patients with symptoms of lower urinary tract obstruction underwent RGU followed by sonourethrography. The sonologist was blinded to the findings of RGU. The parameters studied were compared with the intra-operative findings as gold standard, and the sensitivity, specificity and overall accuracy for the procedures were calculated. Chi-square test and kappa statistics were used where appropriate.

RESULTS

All patients found to have urethral stricture disease by RGU were also detected by sonourethrography and confirmed intra-operatively. In the estimation of stricture length, RGU showed a lower sensitivity (60-80%) for lengths 1-4 cm, compared with sonourethrography (73.3-100%). Spongiofibrosis was detected by sonourethrography with a sensitivity of 77.3-83.3%. All the false tracts and calculi detected at sonourethrography were confirmed at surgery, whereas RGU showed a low sensitivity in their detection. The complications encountered during the procedures were pain, urethral bleeding and contrast intravasation. The frequency of pain during RGU was greater (p < 0.001); however, the difference in frequency of bleeding after the two procedures was not significant (p < 0.5).

CONCLUSION

RGU and sonourethrography are equally efficacious in detection of anterior urethral strictures. Further characterization of strictures in terms of length, diameter and periurethral pathologies, like spongiofibrosis and false tracts, is done with greater sensitivity using sonourethrography as compared with RGU, with the added benefit of lower incidence of complications.

Cyanobacteria in Antarctica: ecology, physiology and cold adaptation

Cyanobacterial species composition of fresh water and terrestrial ecosystems and chemical environment of water in Schirmacher Oasis in Continental Antarctica was investigated. Over 35 species of cyanobacteria were recorded. Diazotrophic species both heterocystous and unicellular contributed more than half to the count except in lake ecosystem. The species composition varied among the fresh water as well as terrestrial ecosystems. The physico-chemical analyses of water revealed its poor nurient content which might have supported the growth of diazotrophic cyanobacteria in an Antarctic environment. Among the cyanobacteria Oscillatoria, Phormidium and Nostoc commune were the dominant flora in most of the habitats. The physiological characteristics of isolated cyanobacteria strains indicated that N2-fixation, nitrate uptake, nitrate-reduction, ammonium-uptake, GS-transferase activity and photosynthesis was unaffected at low temperature (5 degrees C) which indicated low temperature adaptation for Antarctic cyanobacteria. This phenomenon was not evident in different strains of tropical origin. The temperature optima for N2-fixation for the different Antarctic cyanobacterial strains was in the range of 15-25 degrees C, nearly 10 degrees C lower than their respective reference strains of tropical origin. Similar results were obtained for cyanobacteria-moss association. The low endergonic activation energy exhibited by the above metabolic activities supported the view that cyanobacteria were adapted to Antarctic ecosystem.

Quantitative structure-activity relationship study of 5-iodo- and diaryl-analogues of tubercidin: inhibitors of adenosine kinase

The adenosine kinase inhibitory (AKI) activity of 5-iodo and diaryl analogues of tubercidin is quantitatively analyzed using Fujita-Ban and Hansch type analyses. The Fujita-Ban analysis being a non-parametric approach assigned the highest contribution to Cl at the X-position, C6H4-4-Cl, C6H5, 2-furanyl and I at the Y-position and CH2NH2 and CH3 at the Z-position. In addition, a OH substituent at the C-position also emerged as a better choice possibly due to its engagement in hydrogen bonding with some active site function. Thus a compound having Cl, C6H4-4-Cl, CH2NH2 and OH respectively at X-, Y-, Z- and C-positions is predicted to have a potency nearly 1.5 orders of magnitude higher than the most potent compound of the parent data set. The Hansch type analysis, on the other hand, is a parametric approach and is carried out on two sub-sets of original compounds. This sub-division is based on size and nature of the substituents present at the X- and Y-positions. For the compounds in the first sub-set the derived significant correlation equation suggested that the substituent at the Y-position exhibiting a higher field effect and a substituent such as Cl and CH2NH2 at X- and Z-positions, respectively, are important for a compound to show increased AKI activity. Thio/alkylthio at X and CH2OCH3 at Z, on the other hand, lead to a detrimental effect. Similarly for the compounds in the second subset, the derived significant correlation equation showed that a substituent at the X-position having a higher negative field effect, a substituent at the Y-position having bulky groups and the C-position occupied by a OH group are essential for enhancement of the activity of a compound.

Imaging and morphology of the paracondylar process in a dry adult human skull: a case report

An unusually long paracondylar process (PCP) was found articulating with the transverse atlantal process in a dry adult male skull. It was 13 mm long and 19 mm in circumference at its middle and projected to a lower plane than the styloid process of the same side. A radiograph revealed the structure of spongiosa of the PCP to be like mastoid cells. PCP can lead to clinical symptoms due to alterations in posture and functional limitations in neck movements. Thus awareness of this process, its topographical relations and its attendant problems is of importance to clinicians, radiologists, surgeons and chiropractors. In symptomatic cases surgical resection of this process can be attempted to relieve the symptoms. The craniovertebral junction constitutes a unique part of the somite-derived axial skeleton; the lowest part of the basioccipital component including this process develops from occipital sclerotomes. Developmental variations in this region can resemble deformities.

Design of liposomal aerosols for improved delivery of rifampicin to alveolar macrophages

The present study was aimed at preparation, characterization, and performance evaluation of rifampicin-loaded aerosolized liposomes for their selective presentation to alveolar macrophages, that being the most dense site of tuberculosis infection. Egg phosphatidylcholine (PC)- and cholesterol (Chol)-based liposomes were modified by imparting negative charge (using dicetylphosphate, DCP) or by coating them with alveolar macrophage-specific ligands (maleylated bovine serum albumin, MBSA; and O-steroyl amylopectin, O-SAP). The prepared formulations were characterized in vitro for vesicle morphology, mean vesicle size, and percent drug entrapment. Pressurized packed systems based on preformed liposomal formulations in chlorofluorocarbon aerosol propellants were prepared. In vitro airway penetration efficiency of the liposomal aerosols was determined by percent dose reaching the base of the lung, it was recorded 1.5-1.8 times higher as compared to plain drug solution-based aerosol. Percent viability of Mycobacterium smegmatis inside macrophages (in vitro) after administration of drug (in vivo) was in the range of 7-11% in the case of ligand-anchored liposomal aerosols, while it was recorded to be 45.7 and 31.6% in case of plain drug and plain neutral liposomal aerosol (based on PC:Chol)-treated macrophages. Results suggest the preferential accumulation of MBSA- and O-SAP-coated formulations in the lung macrophages, which was further reflected in the periodically monitored in vivo tissue distribution studies. Higher lung drug concentration was recorded in case of ligand-anchored liposomal aerosols and negatively charged liposomal aerosols (based on PC:Chol:DCP) as compared to plain drug and plain liposome-based aerosols. The drug was estimated in the lung in high concentration even after 24h. The drug localization index calculated after 6h was nearly 1.4- and 3.5-fold, respectively, for both ligand-appended liposome-based systems as compared to negatively charged and plain neutral liposome-based aerosolized systems. These results suggest that the ligand-anchored liposomal aerosols are not only effective in rapid attainment of high-drug concentration in lung with high population of alveolar macrophages but also maintain the same over prolonged period of time. The significance of targeting potential of the developed systems was established.

Immunomodulatory effects of aqueous extract of Tridax procumbens in experimental animals

The immunomodulatory properties of ethanol insoluble fraction of aqueous extract of Tridax procumbens Linn. (TPEIF) have been investigated. After intraperitoneal administration of TPEIF in doses of 0.25 and 0.5 g/kg body weight (BW) a significant increase in phagocytic index, leukocyte count and spleenic antibody secreting cells was noticed. Stimulation of humoral immune response was further observed with elevation in heamagglutination antibody titer. Heightened delayed type hypersensitivity reaction suggested convincing evidence for activation of cellular immune system. Protective action of herbal medicine in case of anaphylactic shock was also studied. In addition, elicitation of specific antibody titer against tetanus toxoid (TT) challenge was measured in order to explore the possible use as adjuvant along with clinical vaccination program to reduce number of non-responders. The results suggest that TPEIF influences both humoral as well as cell mediated immune system vis-a-vis assists in genesis of improved antibody response against specific clinical antigen.

Search for Kaluza-Klein graviton emission in pp collisions at square root[s] = 1.8 TeV using the missing energy signature

We report on a search for direct Kaluza-Klein graviton production in a data sample of 84 pb(-1) of ppmacr; collisions at sqrt[s]=1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and one or two high energy jets. We compare the data with the predictions from a (3+1+n)-dimensional Kaluza-Klein scenario in which gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for n=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71 TeV, respectively.

Locomotor activity and behavior of mutant mice deleted for gastrin gene expression

The current studies were initiated to investigate the role of brain-gut peptide, gastrin, on locomotor activity and anxiety-like behavior. Young, male mutant mice, lacking gastrin gene expression (GAS-KO mice), were used in the experiments. The locomotor activity of GAS-KO vs wild type (WT) mice was compared by open field test. The anxiety-like behavior was examined using elevated plus maze. The time and entries to the open arms of the elevated plus maze were used as an indicator for the anxiety-like behavior and the data were analyzed using Hindsight program. On the open field test, locomotor activity of GAS-KO mice was similar to that of the WT mice for the first 10 min of the test, but decreased significantly after that. Anxiety-like behavior was more evident in the GAS-KO vs WT mice in the elevated plus maze experiments. The number of entries to and time spent on the open arms of plus-maze were significantly reduced for the GAS-KO vs WT mice suggesting an increased anxiety-like behavior of GAS-KO mice. Our studies suggest that normal circulating levels of gastrins may play a direct or indirect role in the regulation of locomotor activity and anxiety-like behavior.

Osmotically regulated asymmetric capsular systems for simultaneous sustained delivery of anti-tubercular drugs

Sustained release asymmetric membrane capsular systems were developed for simultaneous oral delivery of rifampicin and isoniazid sodium in order to reduce the problems associated with the multi drug therapy of tuberculosis. Dense semipermeable membrane coating capsules were also prepared for the delivery of these drugs by adopting two different filling approaches. In vitro release studies were carried out for both types of systems and the results were compared. Asymmetric membrane capsules provided sustained release of rifampicin associated with initial burst release, where isoniazid release rates were comparatively high due to higher aqueous solubility. Dense semipermeable membrane systems provided controlled release of both drugs but were devoid of initial burst release of isoniazid. To overcome these drawbacks, a modified asymmetric system was developed by adding appropriate amount of hydrophilic polymer mixture with isoniazid. The system provided satisfactory sustained release of rifampicin and isoniazid with initial burst release may be sufficient to achieve minimum effective concentration in blood. In vitro dissolution kinetics of the systems followed first order kinetics and statistical analysis of release rate data proved that modified asymmetric system was better amongst the developed systems.

Residues of DDT and HCH pesticides in rice samples from different geographical regions of India: a multicentre study

As part of a multicentre study conducted by the Indian Council of Medical Research, 2000 samples of rice were collected from rural and urban areas of 13 states representing different geographical regions of India. The samples were analyzed for residues of DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and different isomers of HCH [1,2,3,4,5,6-hexachlorocyclohexane, a mixture of isomers] by gas-chromatography. Residues of DDT and HCH, respectively, were detected in about 58 and 73% of the samples analysed. Medians of both DDT and HCH in rice samples were around 0.01 mg kg (-1). Concentrations of alpha-, beta-, gamma- and delta-HCH exceeded a maximum residue limit of 0.05 mg kg (-1) for each isomer in rice fixed by the Ministry of Health and Family Welfare of the Indian Government in 4.3, 2.6, 1.7 and 1.2% of the samples, respectively. There is no statutory limit fixed in India for DDT residues in cereals. Its maximum residue limit of 0.1 mg kg (-1) in cereals recommended by Codex was exceeded by about 2% of the samples examined. Estimated intake of DDT and isomers of HCH through consumption of rice contaminated at their median and 90th percentiles constituted a small proportion of their acceptable daily intakes.

Search for pair production of scalar top quarks in R-parity violating decay modes in pp collisions at square root of s=1.8 TeV

We present the results of a search for pair production of scalar top quarks (t(1)) in an R-parity violating supersymmetry scenario in 106 pb(-1) of pp collisions at square root of s=1.8 TeV collected by the Collider Detector at Fermilab. In this mode each t(1) decays into a tau lepton and a b quark. We search for events with two tau's, one decaying leptonically (e or mu) and one decaying hadronically, and two jets. No candidate events pass our final selection criteria. We set a 95% confidence level lower limit on the t(1) mass at 122 GeV/c(2) for Br(t(1)-->tau b)=1.

Controlled Porosity Osmotic Pumps of Highly Aqueous Soluble Drug Containing Hydrophilic Polymers as Release Retardants

Controlled porosity osmotic pumps (CPOPs) are devoid of delivery orifice to release core contents and essentially possess pore-forming agent(s) in coating composition. When the pump comes in contact with aqueous media, pore-forming agent(s) generate pores through which core contents are delivered. Diltiazem hydrochloride (DLTZ) is a freely water-soluble drug and the release rates of DLTZ are higher from oral osmotic pumps including CPOPs, in which the drug release is controlled by concentration of pore-forming agents. The effect of appropriate concentration of hydroxypropyl methyl cellulose and sodium carboxy methyl cellulose mixture on the release of DLTZ from CPOPs was studied. In vitro drug release profiles were compared with that of different marketed controlled release formulations and statistically analysed to examine the suitability of CPOP for twice or once daily administration. Dissolution models were applied to drug release data in order to establish the mechanism of drug release and kinetics. Drug release from the CPOPs was effectively modified with the concentration of pore-forming agent in membrane and concentration of hydrophilic polymers in the core. CPOPs showed minimum 65% of consistent DLTZ release at 16 h. Statistical analysis confirmed that with an increase in the amount of hydrophilic polymers release rate decreased. Drug release from the systems follows Hixson-Crowell cube root model and mechanism of release follow non-Fickian diffusion.

Morphology and imaging of bony projections on sigmoid sulcus with clinical implication

Morphologically diverse osseous projections were observed on the anterior lip of the sigmoid sulcus in a study conducted on 318 dry unsexed adult human skulls belonging to the Indian race. For convenience of description, this lip was divided into a longer lateral part, a shorter medial part and a junctional angular part having bony attributes characterized into three types, crests (42.9%), plates (22.3%) and bridges (13.5%). The bridges were subtyped into incomplete (11.8%) and complete (1.7%). Crests and plates were present anywhere along this lip, while bridges were confined to the angle. Right and left differences were analyzed, which showed that the above findings were more frequent on the right than the left. Plates showed a higher incidence of variation between right and left sides as compared to crests and bridges. Five cadavers were studied, which showed retinacular bands attached to the projections blending with dura mater over the foramen magnum. It is postulated that these projections are caused by the traction of the fibrous dural bands. Axial CT scan revealed partial and complete osseous bridges spanning the sulcus. These projections are of relevance to surgeons working at the cerebellopontine angle. Their presence has not been reported previously.

Acromegaly with fibrous dysplasia: McCune-Albright Syndrome -- clinical studies in 3 cases and brief review of literature--

The McCune-Albright syndrome (MAS) is characterized by a triad of poly/monostotic fibrous dysplasia, café-au-lait macules and hyperfunctioning endocrinopathies including growth hormone (GH) excess. Polyostotic bone lesions and café-au-lait macules are common while monostotic bone lesions are rare. Similarly, acromegaly as a manifestation of endocrine hyperfunction with MAS is uncommon and in most of the instances somatotropinoma has not been documented. We report 3 patients, two of them had monostotic lesion, none had café-au-lait macules and all had GH secreting pituitary macroadenoma. All of them underwent transfrontal pituitary adenomectomy and had histopathological confirmation of GH secreting pituitary adenoma. A brief review of literature is also presented.

Missile injuries of the spine

Between 1995 and 2000, 22 cases with low velocity missile injuries of the spine and spinal cord were treated in three service hospitals. All were adult males, with a mean age of 30.7 years. The wounds were caused by splinters in 18 (82%) and bullets in 4 (18%). Twelve patients received more than one splinter. The cervical and thoracic spines were most frequently involved. In 7 cases, there were injuries to other organs. There was extensive initial deficit (quadriplegia, paraplegia) in 18 (82%) cases, while 4 (18%) had partial deficits. The patients were evaluated by spine radiographs. Myelography was done in 4, CT myelography in 11 and MRI in 4 patients. Two patients had intramedullary hematoma without any skeletal injury, and were treated conservatively. Seventeen patients were treated operatively, and associated injuries of other organs received priority management. Surgery was in the form of debridement, exploration of the spinal cord, hemostasis, decompression and dural repair. Steroids and antibiotics were given routinely. Three patients (2 with cervical and 1 with thoracic spine injury) died preoperatively, and 1 (with dorsolumbar injury) died in the postoperative period due to multi-organ injury. Patients with complete injury remained completely paralyzed, while those with an incomplete injury showed improvement in their neurological grades. The initial neurological grade is the best prognostic indicator, and these injuries are often accompanied by multi-organ injuries. There was no instance of postoperative meningitis or CSF leak. These injuries should be explored for debridement and dural repair.