1125 Proximal Tibial Giant Cell Tumor in A 25-Year-Old Female Treated with Two Stage Extended Curettage, Cementing and Arthrodesis. Key Words: GCT, Two Stage, Curettage, Cementation, Arthrodesis

Introduction

Giant cell tumor of bone is a benign but locally aggressive tumor accounting for approximately 20% of benign osseous neoplasms. Female gender predominance, common in second to third decade of life. Commonly seen around knee, with the distal femur being more frequently involved.

Method

Presenting a 25year old lady with history of progressive pain and swelling around right knee for 2 years and inability to walk for 6 months. Radiography and biopsy revealed giant cell tumor of the right proximal tibia involving the medial condyle. Two staged procedure planned. Stage 1 extended curettage, cementation of cavity with PMMA and a knee spanning fixator was done. In stage 2 at 12 weeks cement was removed and knee arthrodesis using allograft performed retaining the fixator in place.

Results

Patient was able to partially bear weight 6 weeks post 2nd stage of surgery and was able to bear full weight after 12 weeks. A solid arthrodesis was achieved at 5 months post 2nd stage, when the fixator was removed. There is no recurrence at end of one year

Conclusions

This is a novel method of low-cost treatment using bone cement and external fixator for stability. Cement gives immediate structural support and fixator allows ambulation and early weight-bearing. The importance of thorough curettage cannot be overemphasized in preventing recurrence. This can be a viable alternative treatment option for patients presenting with large giant cell tumors around the knee joint who cannot afford options like wide local excision and joint replacement using mega-prosthesis.

A practical approach to diseases affecting dentate nuclei

A wide variety of diseases affect the dentate nuclei. When faced with the radiological demonstration of signal changes in the dentate nuclei, radiologists and clinical neurologists have to sieve through the many possibilities, which they do not encounter on a regular basis. This task can be challenging, and therefore, developing a clinical, radiological, and laboratory approach is important. Information on the topic is scattered and the subject has not yet been reviewed. In this review, a combined clinicoradiological approach is presented. The signal changes in T1, T2, fluid-attenuated inversion recovery (FLAIR), diffusion, susceptibility weighted, and gadolinium-enhanced images can give specific or highly suggestive patterns, which are illustrated. The role of computed tomography (CT) in the diagnostic process is discussed. Specific radiological patterns do not exist in a significant proportion of patients where the clinical and laboratory analysis becomes important. In this review, we group the clinical constellations to narrow down the differential diagnosis and highlight the diagnostic clinical signs, such as tendon xanthomas and Kayser-Fleischer rings. As will be seen, a number of these conditions are potentially reversible, and hence, their early diagnosis is desirable. Finally, key diagnostic tests and available therapies are outlined. The practical approach thus begins with the radiologist and winds its way through the clinician, towards carefully selected diagnostic tests defining the therapy options.

Clinical & genetic analysis of four patients with distal upper limb spinal muscular atrophy

BACKGROUND & OBJECTIVES

Distal upper limb spinal muscular atrophy (SMA) is an uncommon segmental variant of SMA. The condition is usually sporadic, affects males more often than females, and manifests late in the second decade of life, remaining confined to the upper limbs. We examined four patients with this form of SMA in order to determine if they carried homozygous deletion mutations in the survival motor neuron (SMN) or neuronal apoptosis inhibitory protein (NAIP) genes that underlie proximal SMA.

METHODS

The four patients with distal upper limb SMA were analysed clinically, electrophysiologically and biochemically. Genomic DNA from each of the patients was analysed by restriction enzyme digestion of polymerase chain reaction (PCR) amplification products, as well single stranded conformation polymorphism (SSCP), to detect deletion events of selected exons of the SMN and NAIP genes.

RESULTS

The clinical phenotype of the four patients, together with the biochemical and electrophysiological studies, confirmed a diagnosis of distal upper limb SMA. The molecular studies excluded homozygous deletion mutations in these patients as causative of their phenotype.

INTERPRETATION & CONCLUSION

The genetic component underlying distal upper limb SMA appears not to involve mutations that are common in proximal SMA patients. It is possible that genes other than SMN and NAIP may be involved, while somatic mosaicism of SMN gene mutations could be implicated in the segmental nature of distal upper limb SMA.

Gelastic epilepsy--a case report with SPECT studies

A 24 years male presented with daily episodes of uncontrollable laughter followed by urinary incontinence since the age of nine years. Some of these attacks progressed to generalized tonic-clonic seizures. General and neurological examination did not reveal any abnormality. Ictal and interictal video EEGs were normal. MRI showed a hypothalamic hamartoma. Interictal SPECT scan showed normal perfusion in the hamartoma. SPECT scan obtained four minutes after beginning of seizure showed that the perfusion increased in right cingulate gyrus but not in the hamartoma, suggesting the involvement of the cingulate gyrus in the seizure origin or pathway.

Effect of mifepristone on folliculogenesis in women treated with recombinant FSH

OBJECTIVE

To study the mechanism through which mifepristone interrupts folliculogenesis.

DESIGN

Normally ovulating women undergoing donor intrauterine insemination (IUI) treatment were investigated during two menstrual cycles treated with gonadotrophins. In the first cycle (FSH cycle), the women were given 150 IU recombinant FSH (rFSH) s.c. on days 2, 4, 6, 8 and daily thereafter until the administration of hCG. During the second cycle (FSH + mifepristone cycle), the women received rFSH as above plus mifepristone tablets at a dose of 50 mg/day from cycle day 2 until the hCG injection. IUI was performed only in the FSH cycles.

PATIENTS

Eleven normally ovulating women were studied. The women were used as their own controls during the cycle treated with rFSH only.

RESULTS

Two women became pregnant during the FSH cycle and, therefore, data for comparison between the two cycles were available in nine women. In both cycles, only one follicle reached the preovulatory stage. However, during treatment with FSH + mifepristone the growth of the dominant follicle was temporarily arrested after day 8 of the cycle and ovulation was postponed by 2 days on average. Serum FSH values increased significantly in both cycles only during the daily administration of rFSH, i.e. towards the end of the experimental period when a normal growth of the follicle was re-established. On the day of hCG injection, an endogenous LH surge had already started in six of the nine cycles treated with FSH (67%) but in none of the FSH + mifepristone cycles despite the preovulatory oestradiol (E2) levels. Endometrial thickness during the follicular phase and serum E2 and progesterone concentrations during the luteal phase, although in the normal limits, were significantly lower in the FSH + mifepristone than in the FSH cycles.

CONCLUSIONS

These results suggest that mifepristone arrests follicular development at a stage beyond the recruitment-selection point by delaying the growth of the dominant follicle. This is probably achieved through an effect of mifepristone on the ovary where it reduces the sensitivity of the selected follicle to FSH. Mifepristone may have a potential application for the inhibition of the LH surge in superovulation induction programmes.

Structural environment of an essential cysteine residue of xylanase from Chainia sp. (NCL 82.5.1)

N-(2,4-Dinitroanilino)maleimide (DAM) reacts covalently with the thiol group of the xylanase from Chainia leading to complete inactivation in a manner similar to N-ethylmaleimide, but provides a reporter group at the active site of the enzyme. Increasing amounts of xylan offered enhanced protection against inactivation of the xylanase by DAM. Xylan (5 mg) showed complete protection, providing evidence for the presence of cysteine at the substrate-binding site of the enzyme. Kinetics of chemical modification of the xylanase by DAM indicated the involvement of 1 mol of cysteine residue per mol of enzyme, as reported earlier [Deshpande, Hinge and Rao (1990) Biochim. Biophys. Acta 1041, 172-177]. The second-order rate constant for the reaction of DAM with the enzyme was 3.61 x 10(3) M-1.min-1. The purified xylanase was alkylated with DAM and digested with pepsin. The peptides were separated by gel filtration. The specific modified cysteinyl peptide was further purified by reverse-phase HPLC. The active-site peptide was located visually by its predominant yellow colour and characterized by a higher A340 to A210 ratio. The modified active-site peptide has the sequence: Glu-Thr-Phe-Xaa-Asp. The sequence of the peptide was distinctly different from that of cysteinyl peptide derived from a xylanase from a thermotolerant Streptomyces species, but showed the presence of a conserved aspartic acid residue consistent with the catalytic regions of other glucanases.