Self-assembly of oleylamine modified nano-fibrillated cellulose from areca husk fibers into giant vesicles

Nanotechnology involving cellulosic substrates has generated a great attention owing to their exceptional physical and chemical properties. Self-assembled nanostructures obtained from carbohydrate polymers are of interest in the biomedical field for the biocompatibility and non-toxic nature. In the present study modification of nano-fibrillated cellulose (NFC) synthesised from the husk fibers of Areca catechu nuts (AHF) was studied by controlled regio-selective amidation with oleylamine (OA) and characterized. The modified system (MNFC) with more than 66% OA content showed self-assembly into unilamellar vesicles of 2-5μm diameters with a wall thickness of 300-600nm in tetrahydrofuran (THF) at 2.5mgmL^-1. This result is attributed to the folding of MNFC into bilayers driven by long cis-unsaturated aliphatic chains in polar aprotic solvents stabilized by hydrogen bonded interactions within the fibrils. These giant vesicles formed can have applications in storage and delivery of drugs in topical applications.

Preparation of TiO2 Nanoparticle Loaded MCM-41 and Study of Its Photo-Catalytic Activity Towards Decolorization of Methyl Orange

Here we report the synthesis of TiO2 nanoparticle loaded mesoporous MCM-41 photocatalysts for degradation of methyl orange dye in aqueous medium under sunlight exposure. TiO2 loaded MCM-41 was synthesized by impregnation method. Anatase form of TiO2 nanoparticles were formed in the porous matrix of the silicate MCM-41. The synthesized materials were characterized using powder X-ray diffraction method, surface area and porosimetry analysis; diffuse reflectance analysis, particle size analysis and transmission electron microscopy. The photocatalytic property of the synthesized materials were investigated towards the degradation of methyl orange under sunlight exposure and monitored by UV-visible spectrophotometer. Synthesized catalysts showed high photocatalytic activity for the degradation of methyl orange.

Hydrotreatment of renewable oils using hierarchical mesoporous H-ZSM-5 synthesized from kaolin clay

Hierarchical mesoporous ZSM-5 with tailored physicochemical properties was successfully synthesized by using kaolin clay as a cheap alumina source and organosilane as a mesopore directing agent.

Enzymatic esterification of starch using recovered coconut oil

Modification of maize and cassava starches was done using recovered coconut oil and microbial lipase. Microwave esterification was advantageous as it gave a DS 1.55 and 1.1 for maize starch and cassava starch, respectively. Solution state esterification of cassava starch for 36 h at 60 degrees C gave a DS of 0.08 and semi-solid state esterification gave a DS of 0.43. TGA and DSC studies showed that the higher DS attributed to the thermostability, since onset of decomposition is at a higher temperature (492 degrees C) than the unmodified (330 degrees C) and was stable above 600 degrees C. alpha-Amylase digestibility and viscosity reduced for modified starch.

Surface mapping of spike potential fields: visual vs. quantitative EEG analysis

Interictal EEG spike field potentials by visual and quantitative EEG analysis were studied in 17 patients with intractable localization related epilepsy. Quantitative EEG analysis was done using commercially available window based computer program (Focus) that displayed digitally acquired EEG data and performed spline mapping. Routine EEG localized 20 spikes. Fourteen spikes had excellent congruence between manual and computer generated mapping, 6 had good congruence, and 1 had fair congruence. This study clearly proves the usefulness of spline interpolation mapping technique in localizing and characterizing the epileptiform focus.

Animal bite management practices: a survey of health care providers in a community development block of Haryana

It is seen that outcome of animal bites is influenced by various factors including the treatment procedures practiced by health care providers (HCPs). A cross sectional study of health care providers was conducted during May 2000 in PHC Kurali and Naraingarh town of community development block Naraingarh in district Ambala, Haryana. A total of forty-four HCPs were interviewed at their health facility. They were asked about the qualification and number of years in practice. Health care providers were assessed for their knowledge regarding history taking, immediate management of animal bite, post bite anti-rabies treatment, follow up advice and availability of vaccines. Pre-exposure prophylaxis was known to 18.8% of HCPs. Fifty-nine per cent of HCPs were confident in managing dog bites and 93.1% knew about tissue culture vaccine. Vaccine cost was the commonest barrier (38.8%) in the management of animal bites. This study shows a gross difference between awareness and actual practice of management of animal bites.

Isolation of a Nodulisporium species from a case of cerebral phaeohyphomycosis

A fungal infection of the brain of a 55-year-old male patient is reported. The lesion and involved fungus were located exclusively in the right medial temporo-parietal region. The patient was successfully treated with surgical resection of the lesion and antifungal chemotherapy. Few pathogenic dematiaceous fungi exhibit neurotropism and can cause primary infection in the central nervous system (CNS). The etiological agent is described as a Nodulisporium species. To date Nodulisporium has never been reported as an agent of CNS infection in humans.

Sinocranial aspergillosis: a form of central nervous system aspergillosis in south India

Of the 21 patients with aspergillosis of central nervous system seen during the years 1990-1997, 16 (76%) had aspergillosis of sino-cranial origin. The occupation in patients with sino-cranial aspergillosis was either agricultural or manual work and predisposing risk factors were present in only two (12.5%) patients. Skull-base syndromes were the presenting features in 13 patients and three patients presented with features of intracranial space-occupying lesion. Paranasal sinus mass lesions were seen in all the 16 patients. Computerized tomography showed intracranial extradural-enhancing mass lesions in the anterior, middle or posterior cranial fossa in nine (68%) patients, intracranial and orbital lesions in four and orbital lesions in three. Well-formed granuloma with dense fibrosis was the histological feature. Survival rates were not good even after surgical and antifungal chemotherapy. Surgical treatment was subradical in our series. The majority of cases of sinocranial aspergillosis are reported from countries with temperate climates and the high incidence in these regions is probably related to constant exposure to the high spore content of pathogenic Aspergillus species in the 'mouldy' work environment.

Cysts of the central nervous system : a clinicopathologic study of 145 cases

Non-neoplastic, non-inflammatory cysts of the central nervous system may cause symptoms because of pressure, rupture or secondary inflammation. A total of 145 cases of cysts were reviewed during a study period of 12 years. The clinical details and histological features were noted in all cases. During this period 53 epidermoid cysts, 16 dermoid cysts, 38 colloid cysts, 23 arachnoid cysts, 5 neurenteric cysts, 5 ependymal and glial cysts, 2 Rathke's cleft cysts and 3 unclassified cysts were encountered. The possible histogenesis is also discussed.

Neurological intensive care in India--disease spectrum and outcome

In recent years neurological and neurosurgical intensive care (NNICU) has evolved into a well-recognized subspeciality world over. However it is still a novel concept in the developing world. The admission criteria are variable and flexible. The pattern of disease in the NNICU varies according to the admission policy. In the west, cerebrovascular diseases account for a significant proportion of admissions. In a few studies from the developing countries infections of central nervous system are additional causes requiring intensive care. At our center the disease admission pattern was similar to the pattern reported from the developed countries. Predictors of outcome of neurointensive care have not been systematically evaluated. Limited available data concerns patients of neurotrauma. In addition to the disease severity indices, pre-existing chronic illness, adverse events during ICU stay, and the 24-hour presence of a physician also influence patient outcome in the NNICU.

Mycotic aneurysm on posterior cerebral artery: resolution with medical therapy

Mycotic aneurysms on the branches of vertebro basilar artery are rare. A patient of infective endocarditis with mycotic aneurysm on the posterior cerebral artery is described. The aneurysm resolved with medical therapy. Controversies regarding the management of mycotic aneurysms are discussed.

Clinical, pathological and magnetic resonance imaging features of focal myositis: report of three cases

Focal myositis is a rare idiopathic form of inflammatory myositis involving a single muscle. The presentation is often as a soft tissue pseudotumour. Magnetic resonance imaging (MRI) is a useful noninvasive imaging modality to demonstrate focal nature of the lesion. We describe three patients presenting as pseudotumour of the lower leg. MRI showed hyperintense signals in the involved muscle.

Aspergillosis of central nervous system: a study of 21 patients seen in a university hospital in south India

AIM

To study the pattern of central nervous system aspergillosis in a tropical country.

MATERIAL AND METHODS

Case records of patients with CNS aspergillosis seen by the authors in a university hospital in south India were reviewed.

RESULTS

Of the 21 patients seen during the study period, 16 (76%) patients had intracranial invasion by contiguous spread from paranasal sinuses and one had from ear. Predisposing risk factors were present in two (12.5%) patients with sinocranial aspergillosis and in both patients with disseminated form. Skull bases syndromes were the presenting features in 13 patients, six patients presented with features of intracranial space occupying lesion and two patients had stroke like presentation. CT scans showed intracranial extradural contrast enhancing mass lesions in the anterior, middle or posterior cranial fossa in addition to mass lesions in the paranasal sinuses in 13 patients with sinocranial aspergillosis and in seven orbital lesions. Intracerebral contrast enhancing mass lesion was the CT finding in both the patients with solitary cerebral aspergillus granuloma and in the patient with otocranial aspergillus granuloma. Well-formed granuloma with dense fibrosis was the histological feature in patients with sinocranial and otocranial aspergillosis. Angioinvasion was the pathological feature in both the patients with disseminated form of aspergillosis. Surgical treatment was sub-radical in our series. Survival rates were not good even after surgical and antifungal chemotherapy.

CONCLUSIONS

This study suggests that in this part of the world sinocranial aspergillosis is the most common form of histologically verified CNS aspergillosis. Associated predisposing factors and immune status of the host determine the clinical syndrome and type of pathology in patients with CNS aspergillosis.

Characteristics of injuries to the cervical spine and spinal cord in polytrauma patient population: experience from a regional trauma unit

STUDY DESIGN

Retrospective analysis of a prospectively collected trauma database of a Level 1 (tertiary) trauma center.

OBJECTIVE

To define the features of the cervical spinal injuries in polytrauma population admitted to the regional trauma unit.

SETTING

Canada, Ontario Province, Toronto, Sunnybrook Health Sciences Center.

METHODS

All trauma admissions between 1987 and 1996 entered prospectively into a trauma registry database were studied for incidence, demographic and epidemiological details of cervical spine (cord and column) injuries.

RESULTS

A total of 468 patients (66% male) with cervical spinal injury (CSI) from 1198 spinal injuries admitted to the regional trauma center were identified. Seventy-five per cent of the CSI involved were aged less than 50 years; nearly 30% were in the third decade alone. Overall, the commonest spinal level injured was C2 (27%) followed by C5 (22%). Older population (above 60 years of age) had C1 + 2 involved more often than the young (P=0.02). Motor vehicular crashes (MVC) accounted for 71%, followed by pedestrian trauma (10%), sport injuries (7%). Spinal cord injury (SCI) was noted in 27%; complete in 16% and incomplete in 11% and more frequently at C4 or C5 level compared with C1, C2 (P<0.00001); the former level had more often a complete SCI (P=0.06). Though MVC produced 74% of SCI, only 27% had neurological deficits. Recreational trauma produced SCI in 45%, motor cycle crashes (MCC) in 37% and a rear passenger in MVC in 34% that was complete in 78%, 71% and 73% respectively. Front seat passenger and driver in MVC had a C5 level injury while a rear seat passenger had at C4 (P<0.001). The C1 level injury had high association with severe and life threatening head and neck and facial injuries compared with the more frequently injured spinal levels; either C2 (P=0.03) or C5 (P=0.004). Similarly C1 injuries had higher ISS compared with C2 (P<0.0001) and C5 (P<0.008).

CONCLUSIONS

C2 was the commonest fractured spine while SCI was more frequent at C5. Older and pedestrian population had higher incidences of injuries at C1 and C2. Sport and MCC resulted in severe SCI. The level of spine injured was different between a front and a rear seat occupant in MVC.

Plasmacytoma of dens as a cause of atlanto-axial instability

A case of Plasmacytoma of dens (Odontoid Process) in an adult male managed by trans-oral excision and posterior fusion is reported for its rarity. The importance of neuro-imaging and the treatment options, in view of the associated instability at the atlanto-axial region and the difficulty in preoperative diagnosis are emphasized.

Spinal epidural haematoma in a patient with haemophilia-B

Spontaneous spinal epidural haematoma is rare. A case of haemophilia-B presenting with cervical spinal cord compression due to epidural haematoma, is reported. This is the second case in literature, to our knowledge, of intraspinal epidural haematoma in a patient with haemophilia-B. The importance of early diagnosis, especially with magnetic resonance imaging and surgical intervention, when deemed necessary, are emphasized.

Correction of autoimmune lymphoproliferative syndrome by bone marrow transplantation

This report describes a child with a severe phenotype of autoimmune lymphoproliferative syndrome (ALPS) who developed progressive disease requiring stem cell transplantation. This severe form of ALPS was associated with a novel Fas gene splice site mutation that resulted in functional deletion of exons 8 and 9. While this child shared many clinical features with previously described ALPS cases, including massive lymphadenopathy and circulating alphabeta+ CD3+CD4-CD8-T cells, his disease progressed despite immunosuppressive therapy to a clinically aggressive oligoclonal lymphoproliferation which resembled a diffuse large cell non-Hodgkin's lymphoma. After partial remission was achieved with cytotoxic therapy the patient underwent BMT from an unrelated donor. This is the first reported case of ALPS in which BMT was successfully attempted for correction of a Fas deficiency.

Alkaptonuria presenting as lumbar disc prolapse: case report and review of literature

Alkaptonuria is a rare genetic disorder caused by deficiency of the enzyme homogentisic acid oxidase, resulting in accumulation of homogentisic acid in various body tissue; it produces a multisystemic disorder with a characteristic bluish-black discolouration of the skin and cartilage, termed ochranosis. Ochranosis primarily involves the large joints of the body including the spine. Spinal involvement produces loss of flexibility and ankylosis of the thoracic and lumbar segments. The clinical presentation with spondylosis and canal stenosis is common after the third and fourth decades, but intervertebral disc prolapse is unusual in ochranosis.

Analysis of upper and lower extremity peripheral nerve injuries in a population of patients with multiple injuries

BACKGROUND

The purpose of this study was to determine the prevalence, cause, severity, and patterns of associated injuries of limb peripheral nerve injuries sustained by patients with multiple injuries seen at a regional Level 1 trauma center.

METHODS

Patients sustaining injuries to the radial, median, ulnar, sciatic, femoral, peroneal, or tibial nerves were identified using a prospectively collected computerized database, maintained by Sunnybrook Health Science Centre, and a detailed chart review was undertaken.

RESULTS

From a trauma population of 5,777 patients treated between January 1, 1986, and November 30, 1996, 162 patients were identified as having an injury to at least one of the peripheral nerves of interest, yielding a prevalence of 2.8%. These 162 patients sustained a total of 200 peripheral nerve injuries, 121 of which were in the upper extremity. The mean patient age was 34.6 years (SEM +/- 1.1 year), and 83% of patients were male. The mean injury severity score was 23.1 (+/-0.90), and the mean length of hospital stay was 28 days (+/-1.8).

CONCLUSIONS

Motor vehicles crashes predominated (46%) as the cause of injury. The most frequently injured nerve was the radial nerve (58 injuries), and in the lower limb, the peroneal nerve was most commonly injured (39 injuries). Diagnosis of a peripheral nerve injury was made within 4 days of admission to Sunnybrook Health Science Centre in 78% of the cases. Surgery was required to treat 54% of patients. Head injuries were the most common associated injury, occurring in 60% of patients. Other common associated injuries included fractures and dislocations. The present report aims to aid in identification and treatment of peripheral nerve injuries.

Monothiols and Vitamins are Ideal Therapeutic Agents for Mercury Elimination from Nervous and Non-Nervous Tissues of Fish

Use of mercury and its compounds in various industries and agriculture is increasing its concentration in aquatic environment and affecting the organisms living therein. Among these, the fishes are commercially important for humans as an important source of protein. The fish meat transfers good amount of mercury to man, therefore, its elimination is quit essential both from fishes and the consumers. As a step in this direction, the present study has been designed to detoxify the fishes from mercury. For this purpose a freshwater fish (Channa punctatus) was treated with mercuric chloride (0.5 ppm) for 96 h and thereafter, detoxicated with vitamin B complex, glutathione and N-acetyl-DL-homocysteine thiolactone used either alone or in various combinations for another 96 h. One group of 96-h mercury treated animals were kept in tap water and sacrificed after 192 h. This group was considered as mercury washed group and it served as control to all therapeutic groups. Mercury treated fish showed a highest concentration of the metal in kidney followed by liver, gills, brain and muscles. In mercury washed group, metal was removed significantly from all the non-nervous tissues, but in brain about 52% further increase was observed. The results obtained from theraputic studies were quite exciting as 50-80% mercury was mobilized from all tissues including brain within 96 h of treatment.

Upregulation of endogenous p53 and induction of in vivo apoptosis in B-lineage lymphomas of E(mu)-myc transgenic mice by deregulated c-myc transgene

E(mu)-myc transgenic mice carry a constitutively overexpressed c-myc oncogene and develop B-lineage lymphomas. Previous studies have shown that c-myc overexpression can lead to in vitro apoptosis. Here, we investigated the in vivo effects of altered c-myc expression on cell proliferation versus death in spontaneously arising E(mu)-myc tumors. E(mu)-myc tumors display extensive in vivo apoptosis confined to small clusters of cells with greatly increased expression of both the c-myc transgene and the endogenous p53 gene as compared with that in normal, pretumor, or surrounding tumor tissue. This restricted overexpression of both the c-myc transgene and the endogenous p53 gene in small clusters of apoptotic tumor cells indicates that overexpression of these genes and apoptosis are not obligatory or uniform during tumor development and suggests that further somatic mutations or microenvironmental influences may be responsible for these properties. Nevertheless, the clear ability of tumor cells to undergo apoptosis in vivo may be exploitable for therapeutic purposes.

Spontaneous double vessel coronary artery dissection. A case report and surgical management

Spontaneous coronary artery dissection is an uncommon clinical entity, its presentation and management similar to atherosclerotic coronary artery disease. We report on a young adult male who presented with myocardial infarction due to simultaneous dissection of left anterior descending and right coronary artery. He was treated with bilateral interal mammary artery grafts.

Radiosensitizing effect of plumbagin on mouse melanoma cells grown in vitro

Mouse melanoma cells were treated with plumbagin, a naphthoquinone, from the plant Plumbago rosea at 0.5 microgram/ml (PI) for 60 min either alone or followed by 2 Gy gamma radiation (RT). Response to the different treatments was assessed by following the cell growth up to 5 days post treatment. PI alone produced a significant decrease in the cell count on days 3 and 4, whereas RT treatment significantly enhanced the growth inhibitory effect when compared to RT or PI alone. These findings suggests the radiosensitizing effect of PI on mouse melanoma cells in vitro, supporting the earlier in vivo findings.

Heterogeneity of B-lymphoid tumors in E mu-myc transgenic mice

The clinically important issue of tumor heterogeneity was studied in C57BL/6-E mu-myc transgenic mice, which provide a genetically uniform model system in which all animals eventually develop B cell lymphomas after additional genetic changes beyond enforced expression of the transgenic oncogene. Three different approaches were compared for discerning the cellular and genetic homogeneity of these tumors. Analysis of Igh gene rearrangement showed mainly monoclonality and only infrequent oligoclonality in the tumors from a given animal. In contrast, cytogenetic examination indicated a substantial degree of heterogeneity in the tumors from a given animal and showed that a wide variety of secondary genetic changes occur in E mu-myc transgenic mice. Flow cytometry of DNA content also revealed a high degree of heterogeneity within and among the tumor masses from single E mu-myc mice. Estimates of tumor heterogeneity revealed by these three techniques often did not coincide, indicating that these different approaches reflect distinct cellular parameters. Transgenic E mu-myc mice additionally homozygous for the scid mutation displayed enhanced levels of secondary genetic changes that were valuable for the methodological comparisons performed here, and demonstrated that the extent of tumor heterogeneity can be influenced by specific genes other than the primary E mu-myc transgene. In summary, a combination of methodologies appears to be required to reveal the full extent of tumor heterogeneity within a single individual.

Thoracotomy approach for congenital and acquired heart defects: its possible applications in the current era

From April 1975 to February 1995, 305 patients (260 females and 45 males) underwent open heart surgical procedures through the thoracotomy approach. Their ages ranged from 4 months to 55 years (mean age 21.8 +/- 13 years). Two hundred and ninety-seven patients were operated through the right and eight through the left thoracotomy approach. Two hundred and sixteen patients had congenital heart disease and 89 patients had acquired heart diseases, which included ostium secundum defect (190 patients), sinus venosus defect (11 patients), partial atrioventricular (AV) canal defect (5 patients), complete AV canal (1 patient), ventricular septal defect (4 patients), Tetralogy of Fallot (3 patients), anomalous origin of left coronary artery from pulmonary artery (3 patients), mitral valve lesions (83 patients), including tricuspid valve lesions (5 patients) and coronary artery disease (2 patients). Postoperative recovery was observed to be faster (mean hospital stay 7.8 days vs mid-sternotomy 9.6 days), infection rate lower (0.35% vs median sternotomy 2.56%), postoperative drainage lower (148.8 +/- 86.2 mL vs median sternotomy 587 +/- 112.6 mL), and cosmetically found to be much more acceptable in the female population. There have been seven early and one late postoperative deaths which were unrelated to the operative approach. We conclude from this experience that thoracotomy can be safely used as an access for a wide variety of open cardiac surgical operations on the atrial and (upper) ventricular septae, AV valves, right ventricular outflow tract, and coronary artery reconstruction in some situations. It is also useful in some emergency and redo operations with distinct advantages over the median sternotomy approach. We feel its use should be increased as newer subsets of patient populations are being subjected to primary and redo cardiac operations.

Cervico-thoracic neurenteric cyst: clinicoradiological correlation with embryogenesis

Two cases of cervico-dorsal neurenteric cysts are presented, one located dorsal and the other ventral to the spinal cord, with associated Klippel-Feil anomaly, meningocele, spinal dysraphism and possibly spinal cord malformation. One patient was operated on as a neonate for a cervico-thoracic meningocele and presented during adolescence with spastic quadriparesis. Imaging revealed spina bifida, a dorsally located neurenteric cyst and a tendency towards split cord malformation. The other child presented with cervico-thoracic kyphoscoliosis and paraparesis. Imaging demonstrated persistence of a cervico-thoracic remnant of the primitive neurenteric canal through the upper thoracic spine.

Diastematomyelia in adults. Modern imaging and operative treatment

Diastematomyelia, an uncommon dysraphic state usually seen in children, is a rarity in adults; only 19 reports have been published in the literature so far. Two cases of diastematomyelia in adults are presented and the relevant literature is reviewed. Both of these were investigated by computed tomography and magnetic resonance imaging. These two procedures are proved to be complementary to each other in understanding this anomaly. Both patients exhibited associated congenital abnormalities of the neuroectoderm in the form of hyperpigmentation, hypertrichosis, lipomatosis, and dermal sinus that were demonstrated with clarity by the neuroimaging modalities used. Operative correlation was performed in both patients, where findings correlated very well with the preoperative radiological evaluation.

Early surgery for thoracolumbar spinal cord injury: initial experience from a developing spinal cord injury centre in India

The spinal cord injury centre of Nizam's Institute of Medical Sciences, Andhra Pradesh, India has been functioning now for 8 months and offers its services to the population of 80 million in the state. To date, 92 patients with a spinal cord injury have been treated; 51 had a thoracolumbar spinal injury. This report presents the results of the management of these 51 patients. Preoperatively both CT and MRI were performed and the radiological findings were correlated with outcome. Twenty five had a thoracic and 26 a lumber location. Twenty nine patients underwent surgical treatment (15 thoracic and 14 lumbar) and the others were treated conservatively (10 thoracic and 12 lumbar). All these operations were carried out within 2 weeks following trauma, and methylprednisolone therapy was instituted in those who reached the hospital early. Contraindications for surgery included a delay in admission of more than 3 weeks following trauma, a focus of sepsis, bedsores, a generalised bone disorder such as osteopenia, and medical illnesses. Transpedicular screw-plate fixation was performed in 27 patients, and two patients underwent decompressive laminectomy and interlaminar bone and wire fixation. Delayed spinal decompression was offered to one patient to relieve radiculopathy. Fracture-dislocation spinal injury and those with transection of the spinal cord had the worst outcome, whilst patients with a wedge compression fracture and cord oedema fared better. Operated cases had a shorter hospital stay, and complications of immobilisation were limited. Positive psychological influence of mobilisation and early acclimatisation to the altered style of living with their disability were the most significant outcomes following surgery.

Modified supra-arterial myotomy for intermittent coronary obstruction by myocardial bridges

Coronary artery narrowing secondary to myocardial bridging, with consequent clinical manifestation, is a known but uncommon entity. A modified supra-arterial myotomy in a case of myocardial bridge causing medication-refractory angina is described.

Expression of common fragile sites in untreated non-Hodgkin's lymphoma with aphidicolin and folate deficiency

The frequency and distribution of aphidicolin induced and folate sensitive common fragile sites on chromosomes of peripheral blood lymphocytes in untreated non-Hodgkin's lymphoma patients and healthy controls showed a considerable overlap in the expression of common fragile sites between the two groups. However, a significant increase in the expression of 16 aphidicolin induced common fragile sites was seen in untreated lymphoma patients. In the folate deficient cultures only, the common fragile sites 2q22, 8q24, 11q13, 12q21, 16q22, 17p12 and 20p12 were found in both the groups under study. The fragile sites at 8q22, 8q24, 11q13 and 18q21 in patients showed an increased expression over the control group. Interestingly these fragile sites were located in the same chromosomal bands as the oncogenes, MOS, MYC, BCL-1 and BCL-2 as well as cancer breakpoints specifically associated with non-Hodgkin's lymphoma, suggesting the possibility that fragile sites may play a critical role in the pathogenesis of non-Hodgkin's lymphoma.

Apoptosis and macrophage-mediated deletion of precursor B cells in the bone marrow of E mu-myc transgenic mice

Transgenic mice expressing the c-myc proto-oncogene under the control of the Ig heavy chain enhancer (E mu-myc) all eventually develop clonal pre-B- or B-cell tumors. The preneoplastic period is characterized by increased polyclonal proliferation of pro-B and pre-B cells in the bone marrow (BM) associated with a reduced number of B cells, suggesting a high degree of B-cell loss. To examine the mechanisms of this cell loss, we have identified B220+ B-lineage cells within the BM of pretumorous E mu-myc transgenic mice by in vivo radiolabeling and electron microscope radioautography. Large mitotic B220(+)-labeled cells form prominent clusters in the extravascular compartment of the BM. Some B220+ small lymphocytes, as well as large lymphoid cells, enter BM sinusoids. However, in addition, large numbers of B220+ cells exhibit nuclear chromatin condensation, fragmentation, and other morphologic features characteristic of apoptotic cell death. Propidium iodide staining and flow cytometry of BM cells from pretumorous E mu-myc transgenic mice, as well as agarose gel electrophoresis of DNA, confirm extensive apoptosis. Many B220+ apoptotic cells are closely associated with the extensive processes of prominent macrophages that contain numerous B220+ apoptotic bodies and complex lysosomal systems. These results suggest that the constitutive expression of c-myc oncogene in BM B-lineage cells, which increases the proliferation of precursor B cells, also leads to increased apoptotic cell death and rapid elimination by resident macrophages. Further mutations may be needed to block these protective mechanisms and permit surviving c-myc-dysregulated cells to leave the BM and to initiate tumorigenesis.

Calcified medulloblastoma in a child

Calcification is an unusual and atypical feature in medulloblastomas. Here we report a case of calcified medulloblastoma in a 5-year-old boy. The clinical correlation of this radiological finding is discussed.

Posttraumatic pseudomenigocoele of cervical spine in a patient with skeletal fluorosis. Case report

A case of fluorotic cervical compressive myelopathy precipitated by trauma is reported. The delayed neurological deterioration was due to a posttraumatic pseudomenincocele, the prompt treatment of which resulted in recovery. Posttraumatic pseudomeningocele is very rate; and certainly so in fluorosis, and thus has not been reported in the literature to date.