Renal vein leiomyosarcoma: A case report and literature review

A case of leiomyosarcoma of the renal vein occurring in a 48-year-old woman is reported, and the literature is reviewed. Ultrasonography (US) revealed a rounded uniform echogenic mass in the renal hilus. Computed tomography (CT) showed a well-demarcated, uniform, soft tissue density mass. Both US and CT were useful to detect the renal mass in the present case, and may be useful for staging of renal vein leiomyosarcoma. However, these imaging procedures did not reveal diagnostic features of leiomyosarcoma.     

Stimulation of the N-methyl-d-aspartate receptor promotes the biochemical differentiation of cerebellar granule neurons and not astrocytes

Cerebellar granule cells are believed to be glutamatergic, but, as they receive excitatory amino acidergic input from mossy fibers, they also possess N-methyl-d-aspartate (NMDA) receptors. The possible involvement of these NMDA receptors in the biochemical differentiation of cultured granule neurons was studied in terms of the specific activity of phosphate-activated glutaminase, an enzyme important in the synthesis of the putative neurotransmitter pool of glutamate. When the partially depolarized cells were treated with NMDA for the last 3 days (i.e. between 2 and 5 days in vitro), it elevated specific activity of glutaminase in the dose- and time-dependent manners. The half-maximal effect was obtained at about 10 μM NMDA, whereas the maximum concentration, which produced about a 2.7-fold increase in 5-day-old cultures, was about 50 μM NMDA. This increase in glutaminase was completely blocked by the NMDA receptor antagonist, 2-amino-5-phosphonovaleric acid, and by the NMDA receptor-linked Ca²⁺ ion channel blockers, MK 801 and Mg²⁺. The effect of NMDA was not related to the survival of the granule cells, as the experiments were carried out before the dependence on high K⁺ for the survival of granule cells develops in culture, and during the period of investigation none of the compounds used compromised the survival of these cells. The enhancement of glutaminase activity was due to an induction in enzyme protein, since it was completely blocked by cycloheximide and actinomycin D. In contrast to granule neurons, the treatment with NMDA had no significant effect on the activity of glutaminase and glutamine synthetase in cultured cerebellar astroglial cells. Our present results on glutaminase enzyme would indicate that an increase in the cellular concentration of free Ca²⁺ mediated through the NMDA induced increase in Ca²⁺ conductance, leads to long term changes in differentiating cerebellar granule neurons, and it is possible that this kind of physiological stimulation of granule cells is normally provided in vivo by the presynaptic glutamatergic mossy fibers.     

Osteomyelitis of a bone graft of the mandible with Acanthamoeba castellanii infection

An ameloblastoma of the right side of the mandible was resected in a 32 year old prediabetic female. An iliac crest autograft became infected and a sequestrum was removed seven weeks later. Pathologic examination of this tissue demonstrated a mixed infection, including Acanthamoeba castellanii. This is the first recorded instance of invasion of bone by a free living ameba.     

Effect of Anticonvulsant Drugs on Inhibitory and Excitatory Pathways

A conditioning stimulus to the periventricular gray matter inhibits the response of spinal trigeminal neurons to maxillary nerve stimulation. Sodium valproate and ethosuximide decrease the periventricular inhibition without significantly affecting the response of these neurons to the unconditioned maxillary nerve stimulus. We have now found that carbamazepine and phenytoin decrease the response to the unconditioned maxillary nerve stimulus, and only depress the periventricular inhibition secondarily. These results further support the hypothesis that the ability to depress selectively inhibitory pathways in the CNS is an important characteristic of antiabsence drugs, and that absence seizures may represent paroxysmal discharges in inhibitory pathways.     

Glass transition temperatures of copolymers (ethylene glycol/diethylene glycol) terephthalates

Copolymers of (ethylene glycol/diethylene glycol) terephthalates were prepared by melt polycondensation. The values of the glass transition temperatures of the copolyesters, determined by dilatometry are in fair agreement with those predicted by the Fox equation. It was also found that the conformational entropy can be used to correlate equilibrium flexibility and glass transition behaviour of the copolyesters.     

Isolation and characterization of mutants as an approach to a transformation system in Kluyveromyces marxianus

 A method to obtain K. marxianus mutants has been developed. Different auxotrophic mutants were isolated by nystatin and snail-enzyme enrichment procedures using an incubation time of 2 h before adding the antibiotic or the enzyme respectively. All his mutants analyzed by complementation tests turned out to belong to the same complementation group. Some of them were transformed and complemented by the S. cerevisiae HIS3 gene. These non-reverting his3 mutants contain no heterologous sequence, which is essential to make them acceptable for application in the food industry. Received: 15 November/21 December 1995     

Reversion of gingival hyperplasia in a heart transplant patient upon interruption of cyclosporine therapy

A heart transplant patient undergoing a combined cyclosporine and prednisone treatment was monitored during the 18 months following transplantation. A complete oral and dental examination was performed in each of the first six months after transplantation, and then in the 9th, 12th, 15th, and 18th months. The data collected included gingival hyperplasia secondary to cyclosporine use, and clinical and periodontal variables. Histological studies were also conducted on gingival tissue samples in months 1, 3, 9, 15, and 18. Cyclosporine treatment was replaced by azathioprine treatment in month 10 because the patient was experiencing nephrotoxicity. Between months 9 and 18, gingival hyperplasia regressed by 26.5% due to a reduction in the fibrous connective tissue mass, fibroblasts, and inflammatory infiltration. The control group included 13 heart transplant patients subject to equivalent conditions except discontinuance of cyclosporine treatment; seven of the patients had developed hyperplasia by month 9. Average hyperplasia in the control group increased by 2% between months 9 and 18; only one patient showed a 6.2% decrease in hyperplasia. This provides further evidence for the causal relationship between cyclosporine therapy and gingival hyperplasia, and suggests that this side-effect is reversible .     

The heterogeneous temporal evolution of focal ischemic neuronal damage in the rat

Summary Male Fisher rats (n=61) underwent permanent focal cerebral ischemia induced by left middle cerebral artery (MCA) occlusion, in conjunction with ipsilateral common carotid artery ligation. The experiments were terminated at time points ranging from immediately following occlusion to 30 days post MCA occlusion. A coronal histological section, in close proximity to the site of the arterial occlusion, was taken from each brain and divided into six areas encompassing the affected cortex and caudate putamen. Each area was analyzed for ischemic damage according to a grading scale that reflects changes in neuronal morphology. Differential neuronal counts were also made on a 0.5-mm² field in each of the six areas. The areas closest to the occluded vessel showed accelerated ischemic damage between 8 and 12 h after occlusion, leaving open the possibility that before 8 h, therapeutic intervention may be effective. After 12 h, changes in these areas progressed to complete necrosis and eventual cavitation with a complete loss of neurons after 10 days. The areas more peripheral to the occluded vessel exhibited mild ischemic damage, with an apparent reversal of damage grading at later time points and no loss of neurons. This reversal of ischemic damage in the peripheral areas is suggestive of a histological equivalent of the penumbra.Supported by NIH Grants NS23393 and NS29463     

Acute nonlymphocytic leukemia with severe hypodiploidy and one double minute chromosome

We present a case of acute nonlymphocytic leukemia with severe hypodiploidy (38 chromosomes), complex karyotype, and one double minute chromosome. These unusual chromosome findings could be related to the rapid course of the patient's disease.     

Coarctation of the aorta and severe aortic insufficiency: What to repair first?

A new surgical approach is proposed for patients with coarctation of the aorta associated with severe aortic valvular insufficiency. The valvular lesion should be repaired first and the coarctation corrected during a second operation; both interventions should be done during the same hospital stay. We base our approach on the belief that improved coronary perfusion can be achieved when the aortic insufficiency is corrected first. The disadvantages of the opposite surgical approach, such as anticoagulation problems, renal underperfusion, and hypertensive complications are easily avoided.