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.

Management of severe and complicated malaria

Severe malaria is invariably caused by Plasmodium falciparum. In India, both adults and children are affected by severe malaria. However, children are more prone for developing anemia and convulsions as manifestations of severe malaria, while acute renal failure and jaundice are more common among adults. Pregnant women are vulnerable to hypoglycemia, anemia and pulmonary complications. The case-fatality rate due to severe malaria is 10-15% in spite of therapy but it increases in the presence of renal failure or respiratory distress (pulmonary edema or ARDS). Of late, multi-organ failure and high mortality figures are being reported increasingly from different parts of India. Early diagnosis and prompt treatment will reduce the mortality due to malaria. Cerebral malaria should always be suspected in a patient with altered sensorium in a malaria-endemic area. However, other causes of unconsciousness such as encephalitis, meningitis or hepatic coma should also be excluded. Parenteral quinine is the mainstay of therapy. A recent multi-centric study has demonstrated the efficacy of intravenous artesunate in reducing the mortality by 30%. The usefulness of adjunct therapy is still controversial.

Third ventricular colloid cysts in children

INTRODUCTION

Colloid cysts of the 3rd ventricle are relatively rare intracranial tumours, more so in children. They are benign tumours with excellent prognosis if diagnosed and treated early.

METHODS

A retrospective analysis of 18 cases of colloid cysts in children below 18 years, operated in our institution between September 1998 and November 2003 (5 years) was made. Clinical presentation, radiological findings, surgical approaches and outcome were analysed.

RESULTS

Age ranged from 7 to 18 years. The male-to-female ratio was 12:6. Headache and vomiting were the most common symptoms. Papilloedema was the most common clinical sign. Pre-operative CT showed a hyperdense non-enhancing lesion in the majority. Twelve patients underwent a transcallosal, 2 a transcortical and 4 an endoscopic approach. Ventriculoperitoneal shunts were done in 5 patients. Postoperatively 2 patients developed epidural haemorrhage which required evacuation. One patient was re-explored for symptomatic residue. A mean follow-up of 10.2 months was available in 9 patients; the majority were asymptomatic.

CONCLUSION

Colloid cysts though rare are increasingly detected in children. Their early recognition and treatment give excellent results.

Medulloblastoma with extensive nodularity: a variant occurring in the very young-clinicopathological and immunohistochemical study of four cases

CASE REPORT

Four cases of medulloblastoma with extensive nodularity (MBEN) are described. The patients were 3 years of age or younger at diagnosis. Cranial CT scan disclosed multiple coalescing nodules with peculiar 'grape-like' architecture in three patients. A near total excision of the tumour was performed in all four patients. The patients are currently receiving radiation and chemotherapy. Histologically, the tumours were characterized by extreme nodularity with intranodular uniformity and low proliferative index. The internodular zones were extremely cellular, composed of undifferentiated, mitotically active cells. Bcl-2 protein expression was observed in the cellular zones but was distinctly absent within nodules.

DISCUSSION

MBEN represents a variant that occurs in very young children but has a good prognosis. The favourable outcome is probably related to its spontaneous neurocytic differentiation. The pattern of Bcl-2 immunoreactivity in MBENs indicates that this protein could be a key player in the regulation of neuronal differentiation in medulloblastomas.

Evaluation of nimodipine in the treatment of severe diffuse head injury: a double-blind placebo-controlled trial

AIMS

The aim of this study was to establish whether nimodipine given orally soon after severe diffuse head injury for a period of three weeks improved outcome.

MATERIAL AND METHODS

The present report analyzes the results of a prospective randomized double-blind placebo-controlled trial of nimodipine in 97 severe head injury patients (GCS Score < or =8) treated at the Department of Neurosurgery, NIMHANS, between January 1995 and June 1996. The patients were randomly assigned to two groups which were matched for age, sex, mode of injury, time interval from injury to admission, neurological status and CT scan findings. One group was given nimodipine 30 mg Q6H and the other group was given a placebo. The outcome of these patients at 6 months was evaluated using the Glasgow Outcome Score by and a psychologist.

RESULTS

Results showed no significant difference in the functional and psychological outcome between the two groups, even in patients with subarachnoid hemorrhage. No adverse drug events were recorded.

CONCLUSION

Oral nimodipine given for three weeks does not improve outcome in patients with severe diffuse head injury.

Transgenics of an elite indica rice variety Pusa Basmati 1 harbouring the codA gene are highly tolerant to salt stress

Transgenic lines of indica rice were generated by Agrobacterium-mediated transformation with the choline oxidase ( codA) gene from Arthrobacter globiformis. Choline oxidase catalyses conversion of choline to glycine betaine. Glycine betaine is known to provide tolerance against a variety of stresses. Molecular analyses of seven independent transgenic lines as performed by Southern, Northern and Western hybridization revealed integration and expression of the transgene as well as inheritance in the progeny plants. A good correlation was observed between levels of mRNA and protein accumulation, and a significant amount of choline oxidase product, i.e. glycine betaine, accumulated in R0 as well as R1 plants. Mendelian as well as non-Mendelian segregation patterns were obtained in the progeny plants. Challenge studies performed with R1 plants by exposure to salt stress (0.15 M NaCl) for 1 week, followed by a recovery period, revealed that in some cases more than 50% of the transgenic plants could survive salt stress and set seed whereas wild-type plants failed to recover.

Intraoperative bradycardia and postoperative hyperkalemia in patients undergoing endoscopic third ventriculostomy

During our initial experience with endoscopic third ventriculostomies, we observed intraoperative bradycardia and postoperative hyperkalemia. The present study was carried out to verify the consistency of these initial observations. Intraoperative heart rate (HR) changes and postoperative serum K + changes were studied prospectively in 20 patients of endoscopic third ventriculostomy. Another 6 patients who underwent endoscopic procedures other than ventriculostomy acted as controls. The anaesthetic technique and intraoperative and postoperative fluid regimen were similar in all patients. Serum K + concentrations were measured intraoperatively and once a day for the next 5 days. The third ventriculostomy group exhibited a significant slowing of the heart rate during the fenestration of the floor of the third ventricle (112 +/- 26 to 101 +/- 28 bpm, p < 0.001) and also at the time of the reversal of the neuromuscular block at the end of surgery (104 +/- 29 to 96 +/- 33 bpm, p < 0.01). The control group did not exhibit similar changes in the heart rate. The postoperative increase in serum K + values in the ventriculostomy group (0.82 +/- 0.55 mmol/L) was higher than that in the control group (0.10 +/- 0.44 mmol/L) (p < 0.01). Endoscopic third ventriculostomy is associated with a significant bradycardia at the time of fenestration and at the time of reversal of the neuromuscular block. The procedure is also associated with a postoperative increase in serum K + values. We propose a mechanism involving distortion of the posterior hypothalamus, which accounts for the bradycardia and postoperative hyperkalemia.

Pulmonary autograft mitral valve replacement: initial experience with the Ross II procedure

BACKGROUND

The renewed interest in mitral valve replacement with a pulmonary autograft encouraged us to perform this procedure in selected patients.

METHODS AND RESULTS

From August 2000 to February 2002, 10 patients between 30 and 52 years of age with calcific mitral valvular disease underwent the Ross II procedure. Patients were either in New York Heart Association functional class III (7/10) or IV (3/10). Transthoracic echocardiography was done in all the patients to confirm the diagnosis. A pulmonary autograft was used to replace the diseased mitral valve. Intraoperative transesophageal echocardiography confirmed normal functioning of the autograft. There were 2 early deaths. The 8 survivors are in New York Heart Association functional class I with excellent autograft and homograft function at a follow-up of 2-20 months (mean 9 months).

CONCLUSIONS

This procedure is a viable option for mitral valve replacement in patients with calcific mitral valve disease. However, the procedure is technically demanding and requires a valve bank.

Endoscopic approach to intraventricular cysticercal lesions

Various surgical approaches to treat intraventricular cysticercosis have been practiced over the years. We now present our experience with the use of the endoscope in the removal of intraventricular cysticercal cysts in patients with intraventricular cysticercal lesions associated with hydrocephalus. From 1995 to 1998, we have excised intraventricular cysticercal cysts from 9 patients. They were located in lateral ventricle in 4, in the third ventricle in two and in the fourth ventricle in three patients. A Gaab's rigid neuroendoscope system was used to enter and excise cysts in the lateral and third ventricle. The flexible fiberoptic scope was used for excising cysts in the fourth ventricle, through a transaqueductal route. In all cases a precoronal frontal burr hole was used for entry. All have been treated with albendazole in the postoperative period. All the cysts were removed successfully using endoscopic neurosurgery alone. One patient had a superficial injury to the rigid side of the aqueduct with a postoperative deficit, which improved. Three septal perforations, three third ventriculostomies, and one aqueductoplasty were done in the same sitting after cyst removal for CSF diversion. None of the nine cases required further surgery up to date. The follow-up period varied from 12 to 45 months with a median of 18 months. Endoscopic neurosurgery is a minimally invasive technique enabling removal of intraventricular cyticercal cysts from all locations, avoiding major craniotomies/posterior fossa explorations and shunts.

A population genetic analysis of chloroplast DNA in wild populations of Prunus avium L. in Europe

A population genetic study of chloroplast DNA was carried out in 23 wild populations of Prunus avium sampled from several European deciduous forests. An analysis of approx. 9% of the chloroplast genome detected mostly insertion-deletion mutations and one point mutation. In all, 16 haplotypes were detected. Six haplotypes were shared by two or more populations and 10 were unique. One haplotype was present in 21 of the 23 populations and 161 of 211 individuals, which probably indicates its ancient origin. The level of population subdivision, using unordered and ordered alleles, was low, GSTC=0.29 and NSTC=0.33, respectively. The difference between GSTC and NSTC is nonsignificant, indicating an absence of correlation between haplotype phylogeny and geographical distribution. The absence of phylogeographic structure in wild cherry may be attributed to long distance gene flow among populations by birds, animals and anthropogenic activities. The minimum-length spanning tree depicting the phylogenetic relationships between the haplotypes indicates the possible existence of two lineages represented by the haplotypes H3 and H4. The information about homogeneity or heterogeneity of populations in terms of haplotype constitution and detection of rare haplotypes in some populations will be useful for formulation of conservation and management strategies of wild cherry.

Differential effects of glucose on modulation of emotional and nonemotional spatial memory tasks

Research examining the memory-enhancing effects of glucose in humans has been limited to mnemonic tasks lacking affective components, even though glucose may be a mechanism for emotion-induced memory enhancement. This limitation does not permit analysis of interactions between the enhancing properties of emotional stimuli and glucose. Participants were administered either glucose or saccharin 15 min prior to completing a neutral or emotional spatial memory task. Performance under three glycemic conditions (100 mg/kg or 50 g glucose, or placebo) for the two sets of emotional stimuli revealed a significant interaction. Both 100-mg/kg and 50-g doses of glucose resulted in impaired performance for emotional stimuli. For neutral stimuli, a 100-mg/kg dose enhanced memory, whereas a 50-g dose showed no effect. Results indicate that the enhancing effects of emotional stimuli may be attenuated by the consumption of glucose and suggest that recent food consumption should be considered in paradigms examining memory.

Outcome of hepatitis E virus infection in Indian pregnant women admitted to a tertiary care hospital

BACKGROUND AND OBJECTIVES

information on the incidence and prevalence of hepatitis E virus (HEV) infection in Indian pregnant women is scanty. Only a few studies have been done so far to document the vertical route of transmission of this virus. We therefore studied the prevalence of HEV infection in pregnant women with hepatitits and the outcome of their pregnancy.

METHODS

fifty pregnant women with clinical hepatitits were included in the study. After informed consent, their blood samples were tested for potential causes of hepatitis including hepatitis A, B, hepatitis C, and hepatitis E infections.

RESULTS

of the 50 cases, 20 (40%) patients were found to be positive for IgM anti -HEV (group A) and 30 (60%) were negative for IgM anti-HEV antibodies (group B). Overall 19 patients were in their second trimester while 30 were in third trimester. Of these 52.6 per cen (10/19) of those in second trimester and 50 per cent (15/30) in third trimester had fulminant hepatic failure (FHF). Only one patient presented in the first trimester who had acute viral hepatitis (AVH) and recovered completely. Of the HEV infected women, 70 per cent were in their third trimester and remaining 30 per cent in second trimester of pregnancy. A similar percentage of patients i.e., 14 of 20 (70%) manifested with FHF while 6 (30%) had acute hepatitis leading to recovery. The percentage of women with FHF and acute hepatitis was 36.6 and 63 per cent, respectively, in group B. Upon follow up all the 13 of the 14 HEV infected patients with FHF expired and only one delivered a male baby during the illness. The fatality rate in HEV infected patients was not different between the second and third trimesters (66.6% vs. 71.43%), respectively).

INTERPRETATION AND CONCLUSIONS

this study suggests that HEV causes high mortality in pregnant women as compared to non-HEV infected pregnant women. This pilot study indicates that steps should be taken to prevent HEV infection during pregnancy.

Prognostic factors in children with severe diffuse brain injuries: a study of 74 patients

Severe diffuse brain injury in children has a devastating influence on their physical and psychological development. This retrospective study was undertaken to analyse the factors that influence outcome in children with such injuries. The short-term outcomes (Glasgow outcome score) of 74 children (age < or =15 years) with severe diffuse brain injury and no focal operable mass lesions on CT scan, admitted between 1992 and 1998 at the National Institute of Mental Health and Neurosciences were analysed. The prognostic factors analysed were age, gender, time after injury to admission, nature of injury, highest post-resuscitation Glasgow coma score (GCS), pupillary reaction, horizontal oculocephalic reflex and CT scan findings. The following factors were found to be independent predictors of poor outcome: GCS 3-5 (p < 0.003), absent verbal response (p < 0.001), motor response score of 1-3 (p < 0.001), absent pupillary reaction (p < 0.001), absent oculocephalic reflex (p < 0.001) and presence of traumatic subarachnoid haemorrhage on CT scan (p < 0.002). These independent variables were then subjected to a stepwise logistic regression analysis, and the most important variables for predicting outcome were oculocephalic reflex and GCS, which together correctly predicted unfavourable outcome with a sensitivity of 79% and a specificity of 65%. An early CT scan or a single CT scan did not have any prognostic significance.

Analysis of the activity of promoters from two photosynthesis-related genes psaF and petH of spinach in a monocot plant, rice

The subunit III of photosystem I and ferredoxin-NADP(+)-oxidoreductase are encoded by nuclear genes, namely psaF and petH. The activity of their promoters from spinach has been evaluated in transgenic tobacco earlier. Evaluation of the activity of these Dicotyledoneae-specific promoters has been carried out in a monocot system (i.e. rice) by transient gene expression system, based on electroporation-mediated gene delivery into protoplasts from leaves and roots. It has been found that various promoter deletions show higher activity in leaf protoplasts and elements for quantitative response are widely distributed. Transgenic rice has also been produced with a petH promoter and gus reporter gene construct. Although petH promoter is a weak promoter in comparison to the 35S promoter, it expresses well in green tissues and could be useful for plant genetic engineering.

Rice transformation for crop improvement and functional genomics

Although several japonica and some indica varieties of rice have already been transformed, there is significant scope for improvement in the technology for transformation of economically important indica varieties. Successful transformation of rice employing Agrobacterium and recent advances in direct gene transfer by biolistics, evidenced by transfer of multiple genes, have removed some of the serious impediments in the area of gene engineering. The transfer of genes for nutritionally important biosynthetic pathway has provided many opportunities for performing metabolic engineering. Other useful genes for resistance against pests, diseases and abiotic stresses have also been transferred to rice. But the limited knowledge about important target genes requires rapid progress in the field of functional genomics. Transgenic rice system can be applied to isolate new genes, promoters, and enhancers and their functions could be unravelled. The combination of novel regulatory systems for targeted expression and useful new genes should pave the way for improvement of rice and other cereals.

Effects of lesion variables and emotion type on the perception of facial emotion

The purpose of this study was to consider the effects of valence, motoric direction (i.e., approach/withdrawal), and arousal on the perception of facial emotion in patients with unilateral cortical lesions. We also examined the influence of lesion side, site, and size on emotional perception. Subjects were 30 right-hemisphere-damaged (RHD) and 30 left-hemisphere-damaged (LHD) male patients with focal lesions restricted primarily to the frontal, temporal, or parietal lobe. Patient groups were comparable on demographic and clinical neurological variables. Subjects were tested for their ability to match photographs of four facial emotional expressions: happiness, sadness, fear, and anger. Overall, RHD patients were significantly more impaired than LHD patients in perceiving facial emotion. Lesion side, but not site, was associated with motoric direction and valence dimensions. RHD patients had specific deficits relative to LHD patients in processing negative and withdrawal emotions; there were no group differences for positive/approach emotions. Lesion size was not significantly correlated with accuracy of emotional perception.

Diagnostic efficacy of stereotactic biopsies in intracranial tuberculomas

BACKGROUND

Stereotactic biopsies for diagnosing intracranial tuberculomas are often reported to be inconclusive, being confirmatory in only 28% of cases. We analyzed the role and diagnostic efficacy of stereotactic biopsies in the management of intracranial tuberculomas.

METHODS

Twenty patients diagnosed with intracranial tuberculomas based on neuroimaging procedures underwent computerized tomography (CT) guided stereotactic biopsies for histological confirmation. In 10 patients (Group A), biopsies were obtained from the center of the lesion; in the other 10 (Group B), biopsies were obtained from both the enhancing rim and the isodense center and examined separately. The tissues were processed for paraffin sections and hematoxylin eosin staining. In addition, in the first five patients a squash smear from a small portion of the biopsy was prepared, and the cytological features of the cells were examined. All the patients received antitubercular medication and CT scans were repeated 4 months posttreatment.

RESULTS

Histopathological features of the paraffin sections in 17 patients (Group A: 8, Group B: 9) were diagnostic of tuberculoma, whereas the other three revealed only chronic nonspecific inflammation. Based on the cytological features in squash smears, diagnosis could be made in one of five. In two, although the smear was not diagnostic, the histological section from the same specimen confirmed the tuberculous pathology. There was no procedural morbidity or mortality. One patient had a small asymptomatic hematoma at the biopsy site. Three patients died during the follow-up period, due to secondary complications of tuberculosis. Repeat CT scans during follow-up after antituberculous treatment confirmed the reduction in the size of the lesion in 15/17 patients.

CONCLUSION

The high positive yield of stereotactic biopsies in diagnosing tuberculomas argues for their inclusion in the management protocol for tuberculous mass lesions.

High prevalence of sexually transmitted and blood-borne infections amongst the inmates of a district jail in Northern India

Two hundred and forty male and 9 female jail inmates confined for various crimes in a district jail near Delhi were screened for sexually transmitted and blood-borne diseases including HIV, syphilis and hepatitis B and C viral infections, skin diseases etc. The inmates were aged 15-50 years with a mean of 24.8+/-0.11. Their alleged criminal background, period of stay in the jail, drug addiction, education, birth place, marital status, sexual activity, and clinical complaints were recorded by an anonymous questionnaire. Serum samples were tested for antibodies against HIV (1+2), hepatitis C (HCV), Treponema pallidum and for hepatitis B surface antigen (HBsAg). Sputum examination was done for acid-fast bacilli. Out of the 240 men, 115 were married and 125 unmarried. One hundred and eighty-four (76.6%) men gave history of penetrative sex. Of the 184, 53 (28.8%) were homosexuals or bisexuals and 131 (71.2%) had sex with women only. Sixty of the 131 (45.8%) were faithful to their partners while 124 gave a history of having multiple sexual partners and 100 of them (80.6%) had unprotected sex. Eighty-three of these 100 also had had sex with commercial sex workers (CSWs). One hundred and twenty-six were addicted for alcohol, 44 for smack/charas and 8 had a history of intravenous drug abuse. One hundred and seventy-four were not aware of AIDS. On examination 28 of the 240 (11.6%) had active hepatitis with or without a history of jaundice in the last 2 years, 25 (10.4%) active pulmonary tuberculosis (TB) and 11 (4.6%) had syphilitic ulcers on the penis. Four-fifths of the teenagers confined to a particular barrack had moderate to severe scabies. Three males (1.3%) were found to be Western blot confirmed HIV-1 positive while 28 (11.1%) men and 2 (22.2%) women were positive for HBsAg. Twelve (5.0%) men but no women, were found to be positive for anti-HCV antibodies. Out of the 3 HIV-positive persons, one was an intravenous drug user (IVDU), second was a drug addict and frequent CSW visitor while the third was a homosexual. This pilot study gives an indication that sexually transmitted and blood-borne infections are highly prevalent in jail premises and pose a threat of rapid spread of these infections through IVDU and homosexuality.