Functional analysis of human intrafusal fiber innervation by human γ-motoneurons.

Investigation of neuromuscular deficits and diseases such as SMA, as well as for next generation prosthetics, utilizing in vitro phenotypic models would benefit from the development of a functional neuromuscular reflex arc. The neuromuscular reflex arc is the system that integrates the proprioceptive information for muscle length and activity (sensory afferent), to modify motoneuron output to achieve graded muscle contraction (actuation efferent). The sensory portion of the arc is composed of proprioceptive sensory neurons and the muscle spindle, which is embedded in the muscle tissue and composed of intrafusal fibers. The gamma motoneurons (γ-MNs) that innervate these fibers regulate the intrafusal fiber's stretch so that they retain proper tension and sensitivity during muscle contraction or relaxation. This mechanism is in place to maintain the sensitivity of proprioception during dynamic muscle activity and to prevent muscular damage. In this study, a co-culture system was developed for innervation of intrafusal fibers by human γ-MNs and demonstrated by morphological and immunocytochemical analysis, then validated by functional electrophysiological evaluation. This human-based fusimotor model and its incorporation into the reflex arc allows for a more accurate recapitulation of neuromuscular function for applications in disease investigations, drug discovery, prosthetic design and neuropathic pain investigations.

A neglected case of congenital pseudarthrosis of tibia.

Congenital pseudarthrosis of the tibia (CPT) is a rare malformation. It was first described by Hatzoecher in 1708. Treatment options of the congenital pseudarthrosis of tibia are variable and challenging. Various forms of bone grafts such as autologous iliac bone graft or free vascularised fibular graft, bracing, electrical stimulation, external fixators including Ilizarov technique and internal fixation with rods and plates are used. Here we represent a case of congenital pseudarthrosis of the tibia (CPT) of a 15 year-old boy, a shopkeeper hailing from Barhatta, Netrokona and diagnosed by history, clinical examination and x-ray. He was treated by Ilizarov technique and follow up was done for a period of 1 year. Complete union was achieved with correction of angulation and shortening.

Interlocking intramedullary nailing in fracture shaft of the femur.

This prospective study was done to evaluate the result of interlocking intramedullary nailing in fracture shaft of the femur under the Department of Orthopaedic Surgery in Mymensingh Medical College Hospital during the period of January 2007 to December 2008. In this study total 66 patients were purposively selected for interlocking nailing initially but 6 patients did not report in subsequent follow up. So, the result of the study was based on 60 patients. There were 38 males and 22 females with the age range of 18 to 70 years, with an average age of 34 years. Motor vehicle accident was the most common cause of the fracture shaft of the femur (60%) and the second most common cause was fall from height (20%). Right sided involvement was more (66.67%). Majority of the patients had fracture lower third of the femur (70%). Among the patients farmer was the most common (33.33%) group and the next was housewife. The mean union time was 17 weeks with the range of 14 to 30 weeks. Postoperative complications were found, such as infection (3.33%) and nonunion (1.66%). The functional outcome of this study was evaluated by Klemm & Borner criteria. Excellent functional outcome was found in 80%, good in 15% and fair in 5%.

A giant vesical calculus.

Massive or giant vesical calculus is a rare entity in the recent urological practice. Males are affected more than the females. Vesical calculi are usually secondary to bladder outlet obstruction. These patients present with recurrent urinary tract infection, haematuria or with retention of urine. We report a young male patient who presented with defaecatory problems along with other urinary symptoms. The patient having an average built, non diabetic but hypertensive. The stone could be palpated by physical examination. His urea levels were within normal limits but urine examination shows infection. USG reveals bilateral hydronephrosis with multiple stones in both kidneys along with a giant vesical calculus. After controlling urinary infection and hypertention he underwent an open cystolithotomy. During operation digital rectal help was needed to remove the stone as it was adherent with bladder mucosa. Post operative period was uneventful. His urinary output was quite normal and had no defaecatory problems. Patient left the hospital 10 days after operation.

Clinical picture of craniopharyngioma in childhood.

This cross sectional and observational study was carried out among the admitted patients of the department of Neurosurgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka during the period of 1st March 2004 to 31st March 2005. Among the all intracranial tumours, 2.5-04% are Craniopharyngiomas. Although there is a bi-modal age distribution-1st peak at 5-10 years and the 2nd peak at 55-65 years, the common patients are children (9% of childhood tumour). A typical child with Craniopharyngioma (CP) is short, obese and half blind and has a poor school record. The study has been undertaken to know in details, how child patients with Craniopharyngiomas in Bangladesh present their disease at the hospital. Earlier diagnosis and management may improve the quality of life and longivity. The average age of the patients was 13 years ranging from 07 to 17 years. The vast majority patients were admitted with visual problems as their presenting complaints. Among the patients 33% had total blindness of which 03 had primary optic atrophy and 1 has secondary optic atrophy. Among the remaining 08 patients, 75% were found to have field defect. All patients showed fundal changes ranging from early papilloedema to optic atrophy. We found major endocrinological deficiency in child patients with Craniopharyngioma in 17% cases. Raised Prolactin level may not be significant, because it could be due to stalk effect. Although 25% patients were of short stature, their hormonal profile was within normal range according to age and sex.

Perosteal osteosarcoma of clavicle-treated by limb salvaging surgery (total cleidectomy).

Osteosarcoma of clavicle is extremely rare. Improved survival in patients with osteosarcomas has been associated with recent advances in imaging techniques, histopathological methods, surgery and chemotherapy. In most cases the diagnosis can be made with confidence on the x-ray appearance. Other imaging studies like- radioisotope scans may show up-skip lesions, computed tomography (CT) and magnetic resonance imaging (MRI) show the extend of the tumour. Incisional biopsy or excisional biopsy is carried out after careful clinical study and proper investigations. A 30 years old cultivator with a late case of primary osteosarcoma of clavicle was treated with pre-operative and post-operative chemotherapy and was managed with surgical excision of tumor with limb sparing. The patient was clinically disease free for about 08 (eight) months. Then the patient developed recurrences and died 11 (eleven) months after operation.

Clinico-pathological study in large posterior fossa midline tumors.

This cross sectional analytic study was carried out among the admitted patients of the department of Neurosurgery, Bangabandhu Sheikh Mujib Medical University, Dhaka during the period of 1st July 2002 to 31st December 2004. The age ranged from 2.5 years to 70 years. The size of all posterior fossa tumors at presentation were more than 3 cm and the mean size of posterior fossa tumor was 4.38 cm. 62% of posterior fossa mid-line tumors were mixed density in NECT (non-contrast CT). Regarding enhancement characteristics, mild-moderate enhancement and marked heterogeneous enhancement was equally distributed 46% followed by marked homogeneous enhancement only 08%.. The calcification was present only in 07 (14%) patients and most of them were ependymoma. Histopathologically, medulloblastoma was the common variety (32%). The CT scan diagnostic modality sensitivity, accuracy and positive predictive value were 100%, 84.78% and 84.78% respectively but in MRI diagnostic modality 100%, 91.30% and 91.30% respectively.

Opening of plasma membrane voltage-dependent anion channels (VDAC) precedes caspase activation in neuronal apoptosis induced by toxic stimuli.

Apoptotic cell death is an essential process in the development of the central nervous system and in the pathogenesis of its degenerative diseases. Efflux of K(+) and Cl(-) ions leads to the shrinkage of the apoptotic cell and facilitates the activation of caspases. Here, we present electrophysiological and immunocytochemical evidences for the activation of a voltage-dependent anion channel (VDAC) in the plasma membrane of neurons undergoing apoptosis. Anti-VDAC antibodies blocked the channel and inhibited the apoptotic process. In nonapoptotic cells, plasma membrane VDAC1 protein can function as a NADH (-ferricyanide) reductase. Opening of VDAC channels in apoptotic cells was associated with an increase in this activity, which was partly blocked by VDAC antibodies. Hence, it appears that there might be a dual role for this protein in the plasma membrane: (1) maintenance of redox homeostasis in normal cells and (2) promotion of anion efflux in apoptotic cells.