Demonstration of scolex in calcified cysticercus lesion using gradient echo with or without corrected phase imaging and its clinical implications

AIM

This study was performed to determine the magnetic resonance imaging (MRI) sequence that was best suited to demonstrate the scolex in a calcified lesion and to seek the explanation for the appearance of a negative phase in a calcified scolex on corrected gradient refocused echo (GRE) phase imaging.

MATERIALS AND METHODS

Forty-nine patients with single/multiple computed tomography (CT) documented homogeneous calcified lesions and/or calcified scolices in cysts were studied with conventional spin echo and corrected GRE phase imaging. Calcium and different paramagnetic substances from cysticerci scolices of a sample of infected swine muscle were quantified.

RESULTS

The scolex could be demonstrated in 29/39 patients with single calcified lesion. GRE imaging with an echo time of 35ms was the only sequence that demonstrated scolex in all these 29 cases. 15/29 patients with a single calcified lesion, in all 10 patients with multiple calcified lesions and infected swine muscle with multiple cysts and calcified scolex, corrected GRE phase imaging showed negative phase in all these scolices. Estimation of minerals from the calcified scolices from the swine muscle showed by spectroscopic techniques 41.2% of the total mineral contents as paramagnetic substances.

CONCLUSION

We conclude that GRE imaging is the imaging method of choice for demonstration of the scolex in a CT calcified lesion. The negative phase on corrected GRE phase imaging is due to the presence of large amount of paramagnetic substances.

MR imaging and in vivo proton spectroscopy of the brain in neonates with hypoxic ischemic encephalopathy

INTRODUCTION

A number of studies have suggested the potential utility of in vivo proton MR spectroscopy for the evaluation of brain injury in the asphyxiated neonates. We present our initial experience with in vivo proton MR spectroscopy in neonates who were diagnosed as having hypoxic injury on clinical examination and the severity of the insult was graded using Sarnat staging.

METHODS AND MATERIAL

MR imaging and in vivo proton MR spectroscopy was performed in 16 neonates with hypoxic ischemic encephalopathy (HIE) to correlate the imaging and metabolite abnormality with clinical severity of the condition at the time of insult and with outcome at 2 months of age. The ratios of different metabolites were calculated as observed on MR spectroscopy from an 8 ml voxel that included thalami, basal ganglia and part of the ventricular system using spin echo technique with an echo time of 135 ms.

RESULTS AND DISCUSSION

The results of the spectroscopy were compared with imaging abnormalities and Sarnat's clinical staging of HIE. MR Imaging abnormalities included basal ganglia, thalamic and periventricular hemorrhage and periventricular hyperintensities and were noticed in 8/16 neonates with different stages of HIE. Maximum imaging abnormalities were noted in stage II (6/9) followed by stage III (1/2) and stage I (1/5), respectively. The alpha-Glx resonance at 3.76 ppm was seen in 14/16, Glycine at 3.56 ppm (Gly) was seen in 10/16 and Lactate (L) at 1.33 ppm was observed in 4/16 neonates with HIE.

CONCLUSION

MR spectroscopy was more sensitive than imaging in detecting the insult due to HIE and increased concentration of alpha-Glx/Cr and Gly/Cr correlated better with severity of the HIE. The demonstration of L was associated with poor outcome.

Multiparametric quantitation of the perilesional region in patients with healed or healing solitary cysticercus granuloma

The purpose of this study was to compute T2 values and magnetization transfer (MT) ratios in the perilesional region of healing and healed cysticercus granulomas to determine if there are T2 abnormalities not apparent on conventional T2-weighted imaging and to determine the relationship between seizure control and the quantitative measures. Sixty-three patients were studied. T2 values and MT ratios were computed for the perilesional region and were compared with measurements from the contralateral normal-appearing region. A significantly increased T2 value was found for the perilesional region compared to the corresponding contralateral region despite the absence of qualitative abnormality on conventional T2-weighted magnetic resonance imaging. For patients showing normal-appearing perilesional regions on MT imaging, there was no significant difference in T2 and MT ratios between the perilesional and the normal contralateral regions. There was a statistically significant inverse correlation between perilesional T2 values and MT ratios, suggesting each was associated with perilesional gliosis. The study illustrates that quantitative evaluation of MT ratios and T2 augments the qualitative visual assessment of the perilesional region in healing or healed cysticercus granulomas.

Cerebellar hemangioblastoma simulating arachnoid cyst on imaging and surgery

A case of posterior fossa hemangioblastoma simulating arachnoid cyst on imaging and peroperatively is presented. In vivo proton MR spectroscopy showed evidence of large lactate and resonance at 2.37 ppm not observed earlier in the cystic lesions, including arachnoid cyst. The demonstration of this resonance may help in characterization of these lesions that may be confused with arachnoid cysts on imaging and during surgery.

CREB/CBP and SRE-interacting transcriptional regulators are fast on-off switches: duration of calcium transients specifies the magnitude of transcriptional responses

Transient increases in the intracellular calcium concentration, which are associated with electrical activation of neurones, control synapse-to-nucleus communication. Calcium signals differ in time and space but it is unclear exactly how this translates into stimulus-specific gene expression. Analysis of transcription induced by calcium transients with defined durations revealed that the evoked genomic responses, unlike those following neurotrophin exposure, are not all-or-none but graded events. The CRE-binding protein CREB, its coactivator CREB-binding protein (CBP), and SRE-interacting transcriptional regulators are fast on-off switches: their activities are induced by short-lasting calcium signals, remain active for the duration of the signal and are rapidly shut-off after calcium concentrations have returned to basal levels. CREB is switched on by a fast, nuclear calmodulin (CaM) kinase-dependent mechanism that mediates CREB phosphorylation on serine 133 within 30 s of calcium entry. The second calcium-activated route to CREB involves the MAP kinase/extracellular signal-regulated kinase (ERK1/2) cascade. This pathway can be triggered by brief, 30-60 s calcium transients. ERK1/2 activity peaks several minutes after calcium entry and can outlast the calcium transient. The shut-off of CREB and ERK1/2 involves rapid dephosphorylation of their activator sites. These properties of transcription factors and their regulating kinases and phosphatases provide a mechanism through which the duration of calcium signals specifies the magnitude of the transcriptional response. The decoding of temporal features of calcium transients is likely to contribute to impulse-specific gene expression.

Calcium waves induced by hypertonic solutions in intact frog skeletal muscle fibres

1. Regenerative Ca2+ waves and oscillations indicative of calcium-induced calcium release (CICR) activity were induced in fully polarized, fluo-3-loaded, intact frog skeletal muscle fibres by exposure to hypertonic Ringer solutions. 2. The calcium waves persisted in fibres exposed to EGTA-containing solutions, during sustained depolarization of the membrane potential or following treatment with the dihydropyridine receptor (DHPR)-blocker nifedipine. 3. The waves were blocked by the ryanodine receptor (RyR)-specific agents ryanodine and tetracaine, and potentiated by caffeine. 4. In addition to these pharmacological properties, the amplitudes, frequency and velocity of such hypertonicity-induced waves closely resembled those of Ca2+ waves previously described in dyspedic skeletal myocytes expressing the cardiac RyR-2. 5. Quantitative transmission and freeze-fracture electronmicroscopy demonstrated a reversible cell shrinkage, transverse (T)-tubular luminal swelling and decreased T-sarcoplasmic reticular (SR) junctional gaps in fibres maintained in and then fixed using hypertonic solutions. 6. The findings are consistent with a hypothesis in which RyR-Ca2+ release channels can be partially liberated from their normal control by T-tubular DHPR-voltage sensors in hypertonic solutions, thereby permitting CICR to operate even in such fully polarized skeletal muscle fibres.

INGUINAL HERNIA IN FEMALES

9 patients of inguinal hernia in females were diagnosed in a total of 50 patients who presented with congenital groin problems, 8 of these were managed surgically. There were 6 small children, 1 young girl and 2 elderly ladies. All children were managed by herniotomy and herniorrhaphy was done in women. 2 patients under one year presented with irreducible hernia, one of them on exploration was found to be having sliding hernia with incarcerated ovary and tube as contents while other one had incarcerated loop of small intestine. Contents were reduced in both the patients after division of external ring as there was no sign of strangulation. One of our patients never turned up for surgery. All the operated patients were asymptomatic during the follow up period of 6 months to one year with no recurrence or wound infection. None presented on the contralateral side on follow up. Repair of inguinal hernia in females should be carried out at the earliest after a diagnosis is made, because incarceration occurs more frequently in the first year of life, as seen in this study.

Differentiation of tuberculous from pyogenic brain abscesses with in vivo proton MR spectroscopy and magnetization transfer MR imaging

BACKGROUND AND PURPOSE

MR imaging features are nonspecific with respect to the causative organism for patients with brain abscesses. On the basis of the hypothesis that the biochemical environment depends on the infecting organism and might be different in tuberculous compared with pyogenic brain abscesses, this study attempted to determine whether pyogenic brain abscesses can be differentiated from tuberculous brain abscesses by use of magnetization transfer (MT) MR imaging and in vivo proton MR spectroscopy.

METHODS

Twenty-seven patients with a total of 33 pyogenic brain abscesses and three patients with a total of 12 tuberculous abscesses were evaluated with in vivo MR spectroscopy and MT MR imaging. The diagnosis in all cases was based on the culture of the causative organisms and histopathology whenever done as a part of clinical management.

RESULTS

All 27 patients with pyogenic brain abscesses had lipid and lactate levels of 1.3 ppm and amino acid levels of 0.9 ppm with or without the presence of succinate, acetate, alanine, and glycine, while the three patients with tuberculous abscesses showed only such lipid and lactate levels. The MT ratio from the wall of the pyogenic abscesses was significantly higher (P <.001) than that from the tuberculous abscess wall.

CONCLUSION

It might be possible to differentiate tuberculous abscesses from pyogenic abscesses by using MT MR imaging and in vivo MR spectroscopy, which could be of value in influencing the management of such cases.

Normal conduction of surface action potentials in detubulated amphibian skeletal muscle fibres

1. The influence of the transverse (T) tubules on surface action potential conduction was investigated by comparing electrophysiological and confocal microscopic assessments of tubular changes in osmotically shocked and control fibres from frog sartorius muscle. 2. The membrane-impermeant fluorescent dye, di-8-ANEPPs spread readily from the bathing extracellular solution into the tubular membranes in control, intact fibres. Prior exposure of muscles to a hypertonic glycerol-Ringer solution, its replacement by an isotonic Ca(2+)-Mg(2+) Ringer solution and cooling sharply reduced such access. In contrast, dye application in the course of this osmotic shock procedure stained the large tubular vacuoles hitherto associated with successful muscle detubulation. 3. Conduction velocities in intact, control fibres (1.91 +/- 0.048 m s(-1), mean +/- S.E.M., n = 32 fibres) agreed with earlier values reported at room temperature (18-21 degrees C) and were unaffected by prior episodes of steady cooling to 8-10 degrees C (1.91 +/- 0.043 m s(-1), n = 30). 4. Cooling to 11.5 degrees C reduced these velocities (1.47 +/- 0.081 m s(-1), n = 25) but action potential waveforms still included early overshoots and the delayed after-depolarizations associated with tubular electrical activity. 5. In contrast, action potentials from cooled, superficial fibres in osmotically shocked muscles lacked after-depolarization phases implying tubular detachment. Their mean conduction velocities (1.62 +/- 0.169 m s(-1), n = 25) were not significantly altered from values obtained in untreated controls or in intact fibres in muscle similarly treated with glycerol, in direct contrast to earlier results. 6. Cooling produced similar reductions in maximum rates of voltage change dV/dt in action potentials from all fibre groups with lower rates of change shown by detubulated fibres. 7. Use of an antibody to a conserved epitope of the alpha-subunit of voltage-gated sodium channels suggested a concentration of sodium channels close to the mouths of the T tubules. 8. These electrophysiological and anatomical findings are consistent with a partial independence of electrical events in the transverse tubules from those responsible for the rapid conduction of surface regenerative activity. 9. The findings are discussed in terms of a partial separation of the electrical activity propagated over the surface membrane, from the initiation of propagated activity within the T tubules, by the triggering of the sodium channels clustered selectively around the mouths of the T tubules.

TECHNOLOGY UPDATE: PINLESS EXTERNAL FIXATOR

Pinless fixator is an outstanding system designed for external fixation without invading the medullary canal in polytrauma patients. The pinless external fixation allows immediate stabilization and reduction of compound tibial fractures with or without skin loss. This is an ideal tool for emergency stabilization of tibial fractures in a peripheral setup because the application technique is easy to learn by general surgeons. This device can be applied quickly even under local anaesthesia, average application time being 20 minutes in our setup. It does not transfix the bone and therefore avoids the contamination of the medullary canal and thus does not preclude the use of any further treatment methods eg. repeated wound debridement, soft tissue coverage and internal fixation of the fracture. Transportation to referral centre can be done after application of the external fixator if considered necessary in patients with multiple injuries.

Cystic schwannoma--a case report

Cystic change in Schwannoma is uncommon with very few cases reported in literature till date. We present a case clinically mimicking a soft tissue sarcoma but diagnosed on histopathology as cystic schwannoma.

Cervical carcinoma recurring in an abdominal wall incision

Incisional recurrence of carcinoma of the uterine cervix is very rare. We report two patients who developed recurrence in the abdominal wall incision after hysterectomy. The first patient was aged 60 years and had a FIGO Stage IB1 cervical carcinoma treated initially by Wertheim's hysterectomy and postoperative radiotherapy. Nine months after surgery she developed recurrence on the abdominal scar, which was outside the radiation portal. She was treated with electron beam radiation therapy. The second patient developed an incisional recurrence 23 months after surgery and was treated by wide excision of the mass followed by radiotherapy. A survey of the literature identified 12 reported cases to date (eight squamous cell carcinoma and four adenocarcinoma).

Attitudes and treatment outcome of breast conservation therapy for stage I & II breast cancer using peroperative iridium-192 implant boost to the tumour bed

Breast conservation therapy for early breast cancer is an established but grossly under-utilized treatment option in India for various reasons. Breast conservation therapy was offered to 200 suitable breast cancer patients between June 1993 and June 1998. Fifty-one patients (25%) opted for breast conservation and the remaining preferred mastectomy. In patients agreeing to conservation therapy, surgery was performed first along with peroperative implantation of iridium-192 to deliver a boost. Whole breast irradiation of 45 Gy was delivered 3-4 weeks after the boost. Cosmesis was assessed at the end of 6 months from completion of therapy. The main reason for refusal of breast conservation therapy was fear of recurrence in the remaining breast (60%). There were no locoregional failures in our study at a median follow up of 42 months; one patient experienced a systemic relapse. Cosmesis was good to excellent in 80% of patients. Breast conservation therapy using peroperative iridium-192 implant provides excellent locoregional disease control and cosmesis. The results of our study indicate that patient preference for mastectomy is an important reason for the under-utilization of breast conservation therapy in India.

Palliative treatment of advanced non small cell lung cancer with weekly fraction radiotherapy

Various hypofractionated radiotherapy schedules of radiotherapy have been tried in patients of advanced NSCLC with no conclusive superiority of either a more protracted low dose per fraction schedule or a rapid course of large fraction size. Present study evaluates the role of weekly high dose radiotherapy for the palliation of various intrathoracic symptoms like cough, chest pain, hemoptysis, dyspnoea. A total of 47 patients of advanced non-small cell lung cancer were treated with four weekly fraction of 5 Gy to a total dose of 20 Gy. Mean age at presentation was 53 years. Majority of patients had stage III disease. Pain relief was seen in 77% (23/30) patients with complete relief in 57%; haemoptysis was completely relieved in 77% patients (17/22); and cough was relieved in 68% (19/28) patients. Complete relief from dyspnoea was seen in only 5/12 (42%) patients whereas 2/12 (17%) patients had partial response. The present regime of 20 Gy in four weekly fractions was well tolerated by the patients without any identifiable acute toxicity and was simple and convenient to the patients, who traverse a long distance for radiotherapy in India. To conclude, weekly schedule af EBRT provide effective palliation of various intrathoracic symptoms in the patients with advanced NSCLC.

INCISIONAL HERNIA THROUGH NONVERTICAL INCISIONS

Although uncommon, incisional hernia may occur after operations where vertical or paramedian incision is not used. Fifteen patients of incisional hernia through nonvertical incisions in the age group of 22 to 65 years were studied. This included hernia through subcostal incision commonly used for cholecystectomy, gridiron incision, pfannensteil incision and lumbar incisions. Majority of these hernias were due to wound complications and factors which give rise to an increased strain on suture lines. Although the technique for anatomical repair of incisional hernia seems safe and dependable in patients with small defects, but in patients with large musculoaponeurotic defect, prolene mesh hernioplasty has proved successful. In one patient with giant incisional hernia through rooftop incision, large defect was covered with merselene mesh by inlay and onlay technique. After a median follow up of 18 months only one patient (6.6%) developed a recurrence. Merselene mesh has proved to be an excellent material for bridging of wide tissue gaps.

Temporal assessment of quality of life of head and neck cancer patients receiving radical radiotherapy

The study was undertaken to evaluate physical, psychological and functional aspects in quality of life (QoL) assessment prospectively in biopsy-proven head and neck cancer patients receiving radical radiotherapy. Fifty male patients were assessed using Karnofsky's Performance Status (KPS), Beck's Depression Inventory (BDI) and the Functional Living Index-Cancer (FLIC). Patient questionnaires were completed before radiotherapy, during 3-4 weeks of radiotherapy and 3 months after radiotherapy. Before the start of radiotherapy, KPS was 91 +/- 10.26, FLIC was 129.98 +/- 33.41 and BDI was 7.10 +/- 4.57. This indicated good performance and functional status with lower depression. In weeks 3-4 of radiotherapy, KPS (71.00 +/- 20.12) and FLIC (81.34 +/- 45.23) decreased, while BDI (16.56 +/- 9.01) increased, indicating impairment in QoL. Three months after radiotherapy, KPS (78.37 +/- 23.0), FLIC (119.51 +/- 43.62) and BDI (9.02 +/- 7.81) improved but were not restored to pre-treatment levels. When patients were scheduled for radical radiotherapy, maximum deterioration in QoL was seen in weeks 3-4. This is the time when maximum supportive care and psychologic counselling is required.

Chronic pain in the dental patient

This article reviews the pathophysiology and mediators of pain, and addresses the different subtypes of dental pain. An overview of pharmacotherapy is presented. Contributing factors to chronic pain syndromes are reviewed. Alternative methods of pain management are discussed.

Gastrointestinal imaging: a systems analysis comparing digital and conventional techniques

OBJECTIVE

The purpose of this study was to compare digital and conventional methods of gastrointestinal imaging based on the cost of image storage and estimated overall costs, radiation exposure to the patient, and duration of the examination.

MATERIALS AND METHODS

Our study sample consisted of 128 patients who underwent conventional gastrointestinal studies (64 double-contrast upper gastrointestinal examinations and 64 double-contrast barium enemas) and 139 patients who underwent digital gastrointestinal studies (66 double-contrast upper gastrointestinal examinations and 73 double-contrast barium enemas). The number of images and films for each study was recorded, and the mean cost of image storage and the estimated overall costs for digital versus conventional studies were calculated. Both the duration of fluoroscopy and the time from start to completion of the study were obtained from our radiology information system. From these data, we calculated mean radiation exposure to the patient and the duration of the examination. Finally, referring physicians completed a questionnaire about their level of satisfaction with paper prints generated from digital gastrointestinal studies.

RESULTS

When digital studies were compared with conventional studies, the mean cost of image storage decreased by 45% and the estimated overall 10-year costs decreased by 8%. The mean number of spot images increased by 8% for upper gastrointestinal examinations and by 25% for barium enema examinations, whereas the mean duration of fluoroscopy decreased by 4% and by 10%, respectively. As a result, radiation exposure to patients increased by only 2%, a difference that did not approach statistical significance. Finally, the mean duration of examinations decreased by 24% for upper gastrointestinal examinations and by 33% for barium enemas. Approximately 85% of the physicians who completed the questionnaires indicated that they reviewed the paper prints generated from digital studies and that they would like to continue receiving them.

CONCLUSION

Digital gastrointestinal imaging systems are associated with higher initial costs than conventional systems, but the long-term costs of these digital imaging systems are slightly less because of the lower cost of image storage, and radiation exposure to patients is comparable. The shorter duration of digital examinations is a potential benefit of this technology, allowing improved patient throughput. Finally, referring physicians have a high level of satisfaction with paper prints generated from digital imaging.

Control of recruitment and transcription-activating function of CBP determines gene regulation by NMDA receptors and L-type calcium channels

Recruitment of the coactivator CBP by signal-regulated transcription factors and stimulation of CBP activity are key regulatory events in the induction of gene transcription following Ca2+ flux through ligand- and/or voltage-gated ion channels in hippocampal neurons. The mode of Ca2+ entry (L-type Ca2+ channels versus NMDA receptors) differentially controls the CBP recruitment step to CREB, providing a molecular basis for the observed Ca2+ channel type-dependent differences in gene expression. In contrast, activation of CBP is triggered irrespective of the route of Ca2+ entry, as is activation of c-Jun, that recruits CBP independently of phosphorylation at major regulatory c-Jun phosphorylation sites, serines 63 and 73. This control of CBP recruitment and activation is likely relevant to other CBP-interacting transcription factors and represents a general mechanism through which Ca2+ signals associated with electrical activity may regulate the expression of many genes.