CD4-positive lymphoepithelial-like carcinoma: Report of unusual case

We are reporting an unusual case of lymphoepithelial-like carcinoma (LELC) in an 8-year-old female patient where the tumor cells showed unusual CD4 expression. The lesion was found in the left submandibular neck region, in the vicinity of the submandibular gland. The salivary gland was not infiltrated by the tumor, and the tumor exhibited a classic LELC with single and clusters of tumor cells surrounded by many hematolymphoid cells. The tumor cells revealed strong positivity for Epstein-Bar virus as confirmed by the EBER: Epstein-Barr Virus in situ hybridization (EBER-ISH) method of staining. Interestingly, the tumor cells expressed membranous immunostaining for the T-helper lymphocyte antibody (CD4) in addition to pan-cytokeratin. A brief discussion about this unusual finding is offered. The patient was treated as a case of Epstein-Bar virus-associated nasopharyngeal carcinoma with excellent response.

Establishment of a formal program for retinoblastoma: Feasibility of clinical coordination across borders and impact on outcome

Retinoblastoma is an ocular tumor that occurs in young children, in either heritable or sporadic manner. The relative rarity of retinoblastoma, and the need for expensive equipment, anesthesia, and pediatric ophthalmologic expertise, are barriers for effective treatment in developing countries. Also, with an average age-adjusted incidence of two to five cases per million children, patient number limits development of local expertise in countries with small populations. Lebanon is a small country with a population of approximately 4.5 million. In 2012, a comprehensive retinoblastoma program was formalized at the Children's Cancer Institute (CCI) at the American University of Beirut Medical Center, and resources were allocated for efficient interdisciplinary coordination to attract patients from neighboring countries such as Syria and Iraq, where such specialized therapy is also lacking. Through this program, care was coordinated across hospitals and borders such that patients would receive scheduled chemotherapy at their institution, and monthly retinal examinations and focal laser therapy at the CCI in Lebanon. Our results show the feasibility of successful collaboration across borders, with excellent patient and physician adherence to treatment plans. This was accompanied by an increase in patient referrals, which enables continued expertise development. However, the majority of patients presented with advanced intraocular disease, necessitating enucleation in 90% of eyes in unilateral cases, and more than 50% of eyes in bilateral cases. Future efforts need to focus on expanding the program that reaches to additional hospitals in both countries, and promoting early diagnosis, for further improvement of globe salvage rates.

Assessing Radiosensitivity of Bladder Cancer in vitro: A 2D vs. 3D Approach

Background: Bladder cancer is the fourth most commonly diagnosed cancer among males worldwide. Current treatment strategies established for bladder cancer mainly consist of cystectomy yet advances in radiation therapy have pointed to the value of organ-preserving strategies in preserving patients' quality of life. Aim: To study and compare the radiosensitivity in two-dimension (2D) and physiologically-relevant three-dimension (3D) in vitro culture of three human bladder cancer cell lines, RT4, T24, and UM-UC-3. Materials and Methods: Clonogenic assay was performed to assess cells' radiosensitivity in 2D. Employing the 3D Matrigel™-based cultures to enrich for cancer stem cells (CSCs) allowed us to assess the survival of this subpopulation of cells via evaluating the number, i.e., sphere forming unit (SFU), and the sizes of cultured spheres, formed from cells exposed to different radiation doses compared to non-irradiated cells. Results: Irradiating cells with increasing radiation doses revealed highest survival rates with RT4 cells in 2D, followed by T24 and UM-UC-3. In 3D, however, UM-UC-3 cells were shown to be the most radio-resistant as evidenced by the number of spheres formed, yet they displayed the least efficient volume reduction/regression (VR), whilst the volume decreased significantly for both RT4 and T24 cells. Sphere VR and sphere ratio (SR) values were then plotted against each other demonstrating a linear correlation between volume and number with RT4 and UM-UC-3 cell lines, but not T24. Lastly, multiple regression model was employed to evaluate the possibility of obtaining a function combining both 3D parameters, SR and VR, with the surviving fraction (SF) in 2D, and showed a linear regression for T24 cells only, with a correlation coefficient of 0.97 for the combined parameters. Conclusion: We were able to radiobiologically characterize 3 human bladder cancer cell lines showing differential effects of radiation between 2D and 3D culture systems, paving the way for achieving better assessment of radiosensitivity of bladder cancer in vitro.

Predictors of Cardiac Sparing in Deep Inspiration Breath-Hold for Patients With Left Sided Breast Cancer

Purpose: The purpose of this study was to evaluate patient-related non-dosimetric predictors of cardiac sparing with the use of deep inspiration breath-hold (DIBH) in patients with left-sided breast cancer undergoing irradiation (RT).

Materials and Methods: We retrospectively reviewed charts and treatment plans of one-hundred and three patients with left-sided breast cancer. All patients had both free-breathing (FB) and DIBH (with body surface tracking) plans available. (MHD) and V4 (heart volume receiving at least 4 Gy) were extracted from dose volume histograms. Fisher's exact and Chi-square tests were used to identify predictors of reductions in MHD and V4 after DIBH.

Results: One-hundred and three patients were identified and most underwent mastectomy. MHD and V4 decreased significantly in DIBH plans (0.74 ± 0.25 Gy vs. 1.72 ± 0.98 Gy, p < 0.0001 for MHD; 4 ± 4.98 cc vs. 20.79 ± 18.2 cc, p < 0.0001 for V4). Body mass index (BMI), smoking and timing of CT simulation (spring/winter vs. summer/fall) were significant predictors of reduction in MHD whereas BMI, field size, chemotherapy, axillary dissection, and timing of CT simulation predicted reduction in V4. On multivariate analysis, BMI, and timing of CT simulation remained significant predictors of the heart-sparing effect of DIBH.

Conclusions: In the setting of limited resources, identifying patients who will benefit the most from DIBH is extremely important. Prior studies have identified multiple dosimetric predictors of cardiac sparing and hereby we identified new non-dosimetric factors such as BMI and timing of treatments.

Collaborative Pediatric Bone Tumor Program to Improve Access to Specialized Care: An Initiative by the Lebanese Children's Oncology Group

BACKGROUND

Children with malignant bone tumors have average 5-year survival rates of 60% to 70% with current multimodality therapy. Local control modalities aimed at preserving function greatly influence the quality of life of long-term survivors. In developing countries, the limited availability of multidisciplinary care and limited expertise in specialized surgery and pediatric radiation therapy, as well as financial cost, all form barriers to achieving optimal outcomes in this population.

METHODS

We describe the establishment of a collaborative pediatric bone tumor program among a group of pediatric oncologists in Lebanon and Syria. This program provides access to specialized local control at a tertiary children's cancer center to pediatric patients with newly diagnosed bone tumors at participating sites. Central review of pathology, staging, and treatment planning is performed in a multidisciplinary tumor board setting. Patients receive chemotherapy at their respective centers on a unified treatment plan. Surgery and/or radiation therapy are performed centrally by specialized staff at the children's cancer center. Cost barriers were resolved through a program development initiative led by St Jude Children's Research Hospital. Once program feasibility was achieved, the Children's Cancer Center of Lebanon Foundation, via fundraising efforts, provided continuation of program-directed funding.

RESULTS

Findings over a 3-year period showed the feasibility of this project, with timely local control and protocol adherence at eight collaborating centers. We report success in providing standard-of-care multidisciplinary therapy to this patient population with complex needs and financially challenging surgical procedures.

CONCLUSION

This initiative can serve as a model, noting that facilitating access to specialized multidisciplinary care, resolution of financial barriers, and close administrative coordination all greatly contributed to the success of the program.

Wilms tumor: Successes and challenges in management outside of cooperative clinical trials

OBJECTIVE/BACKGROUND

Management of Wilms tumor (WT) in children depends on a multidisciplinary approach to treatment, and outcomes have significantly improved as reported by cooperative group clinical trials. Here, we review the clinical outcomes of patients with WT and identify challenges and barriers encountered in multidisciplinary management outside of cooperative clinical trials.

METHODS

We retrospectively reviewed the clinical records of 35 children with WT treated between April 2002 and June 2013 at the Children's Cancer Institute in Lebanon.

RESULTS

Upfront resection was performed in 23 cases. Biopsies were performed for Stage V tumors (n=4), those with unresectable tumors or inferior vena caval thrombus (n=5), and patients who had partial surgery performed elsewhere prior to presentation (n=2). One patient died due to toxicity prior to surgery. The tumor was Stage I in eight patients, Stage II in five patients, Stages III and IV in nine patients each, and bilateral (Stage V) in four patients. Adherence to The National Wilms Tumor Study-5 recommendations was adequate. At the time of analysis, 30 patients were free of disease and four patients had relapse-all having metastatic disease initially.

CONCLUSION

The National Wilms Tumor Study-5 therapy resulted in favorable outcomes in children with nonmetastatic Wilms tumor in the setting of a multidisciplinary approach to therapy and resolution of financial barriers to medical care. Upstaging due to prior intervention and lung radiation therapy to all those with computed tomography-detected lung nodules may both have resulted in overtreatment of a subset of patients. Finally, the relatively high incidence of bilateral tumors suggests the need for further genetic and molecular studies in this patient population.

Morbidity of redo surgery for thyroid disease

OBJECTIVE

Redo thyroid surgery is generally associated with more complications than firsthand surgery. The actual study reports a single center experience of redo thyroid surgery compared to primary bilateral thyroidectomy.

STUDY DESIGN

Mono institutional retrospective study.

METHODS

Institutional review of redo thyroid surgery patients (Group 2 : completion thyroidectomy and Group 3 : thyroidectomy for recurrent thyroid diseases) compared to Group 1 : primary bilateral thyroidectomy operated on during the same time interval.

RESULTS

Demographic characteristics were not different between groups. Substernal extension and hyperthyroidism were more frequent in group 1. Weight of the resected thyroid gland was lower in groups 2 and 3. Incidence of transient hypocalcemia, permanent hypoparathyroidism, transient and permanent recurrent laryngeal palsy was not different between the groups. Hematoma occurred in 5% of cases in the 3 groups and postoperative length of stay was 1 day in 92% of cases of the 3 groups.

CONCLUSIONS

Redo thyroid surgery can be performed with no excess morbidity provided strict selection criteria, having reoperation in mind while performing firsthand intervention.

Outcome of Ewing sarcoma in a multidisciplinary setting in Lebanon

Treatment of Ewing sarcoma (ES) necessitates coordinated multi-disciplinary care. We analyzed outcome for 39 patients treated at a single institution in Lebanon, a developing country with available multidisciplinary treatment modalities, where financial barriers to care are overcome by a fundraising system. Median follow-up was 58 months. Five-year overall and event-free survival were 76% and 58%, respectively, for localized disease, and 40% and 38%, respectively, for metastatic disease. We conclude that, in a country with emerging economy, by following international protocols and ensuring availability of needed resources, outcome of patients with ES is similar to that in developed countries.

Evaluation of chromogenic medium and direct latex agglutination test for detection of group B streptococcus in vaginal specimens from pregnant women in Lebanon and Kuwait

This study was undertaken to evaluate chromogenic medium and a direct latex agglutination test (DLA) for detection of Group B Streptococcus (GBS) in the vaginal specimens of pregnant women, and to ascertain the prevalence of GBS in this population in Kuwait and Lebanon. Vaginal swabs, collected from women at 35-37 weeks of gestation, were cultured on 5 % sheep blood agar (SBA), colistin nalidixic acid agar (CNA), Strept B Select chromogenic agar (SBS) as well as Lim enrichment broth in 168 cases in Lebanon while only SBA was used for 1391 samples in Kuwait. In addition, vaginal samples from 102 GBS-positive and 20 GBS-negative women near the time of delivery were collected in Kuwait for evaluation of the DLA test. During the study period, the prevalence of GBS colonization was determined to be 20.7 % (288/1391) in Kuwait while 18.4 % (31) of 168 pregnant women in Lebanon had vaginal cultures positive for GBS. By direct plating of vaginal swabs on the three media used, the isolation rates of GBS were 51.6, 64.5 and 77.4 % on SBA, CNA and SBS, respectively, which increased to 90.35, 93.1 and 96.8 %, respectively, following subculture in Lim broth after 18 h of incubation. The sensitivity of the DLA test was found to be dependent on the density of GBS colonization, resulting in 100 % sensitivity and 100 % specificity for heavy (>10(2) c.f.u. per swab) and moderately heavy (50-100 c.f.u. per swab) growth of GBS. However, for vaginal specimens yielding <50 c.f.u. per swab, the sensitivity, specificity, positive and negative predictive values of the DLA test were 100, 55.5, 63.6 and 100 %, respectively. In conclusion, a chromogenic agar, such as SBS, and a DLA test can be used for rapid detection of GBS in pregnant women. The DLA test, in particular, could prove to be a useful tool for immediate detection of GBS in women near delivery so that intrapartum antibiotic prophylaxis can be initiated.

Rhabdomyosarcoma treatment and outcome at a multidisciplinary pediatric cancer center in Lebanon

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Outcome of patients treated on standard protocols, in a multidisciplinary cancer center setting outside of clinical trials, is not well reported. We reviewed characteristics and outcome of 23 pediatric patients treated at a single, multidisciplinary cancer center in Lebanon, between April 2002 and December 2010. Median follow-up was 41 months. The most commonly affected primary site was the head and neck (48%, n = 11). Nineteen tumors (82.6%) were of embryonal histology. Tumor size was ≥5 cm in eight (34.8%) patients. Sixteen patients (69.6%) had localized disease, and one (4.4%) had metastatic disease. Fifteen (65.2%) had Group III tumors. All patients received chemotherapy, for a duration ranging 21-51 weeks. Upfront surgical resection was performed in 10 patients (43.5%). Eighteen patients (78.3%) received radiation therapy. The 5-year overall and disease-free survival rates were 83% and 64%, respectively. Relapse correlated with absence of surgery. Treatment of childhood RMS in a multidisciplinary cancer center in Lebanon results in similar survival to that in developed countries when similar protocols are applied. There was a higher incidence of local relapse, but those were salvageable with further therapy and surgical local control.

Breast cancer patients with 10 or more involved axillary lymph nodes treated by multimodality therapy: influence of clinical presentation on outcome

PURPOSE

To analyze tumor control and survival for breast cancer patients with 10 or more positive lymph nodes without systemic disease, treated by adjuvant radiation alone or combined-modality therapy.

METHODS AND MATERIALS

We reviewed the records of 309 consecutive patients with these characteristics who received locoregional radiotherapy (RT) at our institution. The majority of patients had clinical Stage II or IIIA-B disease (43% and 48%, respectively). The median number of positive axillary lymph nodes was 15 (range, 10-78). Adjuvant therapy consisted of RT alone, with or without chemotherapy, tamoxifen, and/or ovarian castration.

RESULTS

The overall 5-year and 10-year disease-free survival (DFS) rates were 20% and 7%, respectively. Median DFS was higher for patients with Stage I-II compared with those with Stage IIIABC (28 vs. 19 months; p = 0.006). Median DFS for patients aged <or=35 years was lower than that of older patients (12 vs. 24 months; p < 0.0001). Patients treated with a combination therapy had a higher 5-year DFS rate compared with those treated by RT alone (26% vs. 11%; p = 0.03). In multivariate analysis, clinical stage (III vs. I, II; relative risk = 1.8, p = 0.002) and age (<or=35 vs. others; relative risk = 2.6, p <0.001) were found to be independent variables for DFS.

CONCLUSION

This retrospective data analysis identified young age and advanced clinical stage as pertinent and independent clinical prognostic factors for breast cancer patients with advanced axillary disease (10 or more involved nodes). These factors can be used for further prognostic classification.

Changes in glial glutamate transporters in human epileptogenic hippocampus: Inadequate explanation for high extracellular glutamate during seizures

Temporal lobe epilepsy (TLE) with hippocampal sclerosis is associated with high extracellular glutamate levels, which could trigger seizures. Down-regulation of glial glutamate transporters GLAST (EAAT1) and GLT-1 (EAAT2) in sclerotic hippocampi may account for such increases. Their distribution was compared immunohistochemically in non-sclerotic and sclerotic hippocampi and localized only in astrocytes, with weaker immunoreactivity for both transporters in areas associated with pronounced neuronal loss, especially in CA1, but no decrease or even an increase in areas with less neuronal loss, like CA2 and the subiculum in the sclerotic group. Such compensatory changes in immunoreactivity may account for the lack of differences between the groups in immunoblot studies as blots show the average concentrations in the samples. These data suggest that differences in glial glutamate transporter distribution between the two groups of hippocampi may be an insufficient explanation for the high levels of extracellular glutamate in sclerotic seizure foci observed through in vivo dialysis studies.

Loss of glutamine synthetase in the human epileptogenic hippocampus: possible mechanism for raised extracellular glutamate in mesial temporal lobe epilepsy

BACKGROUND

High extracellular glutamate concentrations have been identified as a likely trigger of epileptic seizures in mesial temporal lobe epilepsy (MTLE), but the underlying mechanism remains unclear. We investigated whether a deficiency in glutamine synthetase, a key enzyme in catabolism of extracellular glutamate in the brain, could explain the perturbed glutamate homoeostasis in MTLE.

METHODS

The anteromedial temporal lobe is the focus of the seizures in MTLE, and surgical resection of this structure, including the hippocampus, leads to resolution of seizures in many cases. By means of immunohistochemistry, western blotting, and functional enzyme assays, we assessed the distribution, quantity, and activity of glutamine synthetase in the MTLE hippocampus.

FINDINGS

In western blots, the expression of glutamine synthetase in the hippocampus was 40% lower in MTLE than in non-MTLE samples (median 44 [IQR 30-58] vs 69 [56-87]% of maximum concentration in standard curve; p=0.043; n=8 and n=6, respectively). The enzyme activity was lower by 38% in MTLE vs non-MTLE (mean 0.0060 [SD 0.0031] vs 0.0097 [0.0042] U/mg protein; p=0.045; n=6 and n=9, respectively). Loss of glutamine synthetase was particularly pronounced in areas of the MTLE hippocampus with astroglial proliferation, even though astrocytes normally have high content of the enzyme. Quantitative immunoblotting showed no significant change in the amount of EAAT2, the predominant glial glutamate transporter in the hippocampus.

INTERPRETATION

A deficiency in glutamine synthetase in astrocytes is a possible molecular basis for extracellular glutamate accumulation and seizure generation in MTLE. Further studies are needed to define the cause, but the loss of glutamine synthetase may provide a new focus for therapeutic interventions in MTLE.

Disruption of inhibition in area CA1 of the hippocampus in a rat model of temporal lobe epilepsy

Previous studies have revealed a loss of neurons in layer III of the entorhinal cortex (EC) in patients with temporal lobe epilepsy. These neurons project to the hippocampus and may activate inhibitory interneurons, so that their loss could disrupt inhibitory function in the hippocampus. The present study evaluates this hypothesis in a rat model in which layer III neurons were selectively destroyed by focal injections of the indirect excitotoxin, aminooxyacetic acid (AOAA). Inhibitory function in the hippocampus was assessed by evaluating the discharge of CA1 neurons in response to stimulation of afferent pathways in vivo. In control animals, stimulation of the temporo-ammonic pathway leads to heterosynaptic inhibition of population spikes generated by subsequent stimulation of the commissural projection to CA1. This heterosynaptic inhibition was substantially reduced in animals that had received AOAA injections 1 mo previously. Stimulation of the commissural projection also elicited multiple population spikes in CA1 in AOAA-injected animals, and homosynaptic inhibition in response to paired-pulse stimulation of the commissural projection was dramatically diminished. These results suggest a disruption of inhibitory function in CA1 in AOAA-injected animals. To determine whether the disruption of inhibition occurred selectively in CA1, we assessed paired-pulse inhibition in the dentate gyrus. Both homosynaptic inhibition generated by paired-pulse stimulation of the perforant path, and heterosynaptic inhibition produced by activation of the commissural projection to the dentate gyrus appeared largely comparable in AOAA-injected and control animals; thus abnormalities in inhibitory function following AOAA injections occurred relatively selectively in CA1. Electrolytic lesions of the EC did not cause the same loss of inhibition as seen in animals with AOAA injections, indicating that the loss of inhibition in CA1 is not due to the loss of excitatory driving of inhibitory interneurons. Also, electrolytic lesions of the EC in animals that had been injected previously with AOAA had little effect on the abnormal physiological responses in CA1, suggesting that most alterations in inhibition in CA1 are not due to circuit abnormalities within the EC. Comparisons of control and AOAA-injected animals in a hippocampal kindling paradigm revealed that the duration of afterdischarges elicited by high-frequency stimulation of CA3, and the number of stimulations required to elicit kindled seizures were comparable. Taken together, our results reveal that the selective loss of layer III neurons induced by AOAA disrupts inhibitory function in CA1, but this does not create a circuit that is more prone to at least one form of kindling.

Ibotenate injections into the pre- and parasubiculum provide partial protection against kainate-induced epileptic damage in layer III of rat entorhinal cortex

PURPOSE

A loss of neurons in layer III of the entorhinal cortex (EC) is often observed in patients with temporal lobe epilepsy and in animal models of the disorder. We hypothesized that the susceptibility of layer III of the EC to prolonged seizure activity might be mediated by excitatory afferents originating in the presubiculum.

METHODS

Experiments were designed to ablate the presubiculum unilaterally by focal ibotenate injections and to evaluate the effect of this deafferentation on the vulnerability of EC layer III neurons to the chemoconvulsant kainate (injected systemically 5 days later).

RESULTS

After treatment with kainate, 11 of the 15 rats preinjected with ibotenate showed clear-cut, partial neuroprotection in layer III of the EC ipsilateral to the ibotenate lesion. Serial reconstruction of the ibotenate-induced primary lesion revealed that entorhinal neurons were protected only in animals that had lesions in the pre- and parasubiculum, especially in the deep layers (IV-VI).

CONCLUSIONS

The deep layers of the pre- and parasubiculum appear to control the seizure-induced damage of EC layer III. This phenomenon may be of relevance for epileptogenesis and for the pathogenesis of temporal lobe epilepsy.

Neurons in layer III of the entorhinal cortex. A role in epileptogenesis and epilepsy?

A preferential lesion of neurons in layer III of the entorhinal cortex (EC) is often observed in patients suffering from temporal lobe epilepsy and in several animal models of the disease. This lesion is duplicated in rats by a focal, intra-entorhinal injection of the "indirect" excitotoxin aminooxyacetic acid (AOAA), providing a model that can be used to study the mechanisms underlying seizure-induced cell death and epilepsy. Doomed neurons in the EC and in several associated limbic structures show pathological changes within hours after the AOAA injection, but GABAergic neurons in layer III of the EC are quite resistant. This pattern of neuron loss eventually results in hippocampal and entorhinal hyperexcitability. Notably, the seizure-induced death of layer III neurons in the EC can be attenuated by eliminating the prominent excitatory input from the presubiculum. Taken together, these results suggest opportunities to target parahippocampal structures for the treatment of temporal lobe epilepsy.

A modified technique for tibial interference screw fixation of hamstring anterior cruciate ligament grafts

This article describes a modified technique for tibial fixation of quadrupled hamstring grafts in anterior cruciate ligament reconstruction. Using this technique common problems with tibial interference screw fixation of hamstring grafts-such as loss of tension of the graft during screw introduction or twisting of the graft in the tunnel around the screw-are avoided.

Ultrastructure and immunocytochemical distribution of GABA in layer III of the rat medial entorhinal cortex following aminooxyacetic acid-induced seizures

Layer III of the entorhinal cortex (EC) is lesioned in patients with temporal lobe epilepsy (TLE). A similar neuropathology is also present in different animal models of TLE. For example, injection of the "indirect" excitotoxin aminooxyacetic acid (AOAA) into the EC of rats causes behavioral seizures and preferential loss of neurons in layer III of the medial EC. The animals also develop hyperexcitability of the EC and the hippocampal region CA1. To further explore the neuropathological changes within the EC, the ultrastructure and distribution of GABA-like immunoreactivity were assessed in layer III, 28 days after an intraentorhinal AOAA injection. At this time point, light microscopic preparations revealed that a large proportion of pyramidal (putative excitatory) neurons in layer III of the medial EC had degenerated, whereas GABA-immunoreactive neurons had survived. In immunogold-labeled ultrathin sections, the lesioned neuropil was found to contain morphologically intact GABA-containing neurons and nerve terminals. Pathologically swollen dendrites and electron-dense neuronal profiles were present in the lesioned sector as well. The majority of the electron-dense profiles was identified as degenerating dendritic spines that were closely apposed to strongly glutamate-immunopositive axon terminals. Thus, the entorhinal chemoarchitecture is dramatically altered following an episode of AOAA-induced epileptic seizures. One possible consequence of this pathology is a reduced "drive" of the surviving layer III GABA neurons, which in turn may cause hyperexcitability of the EC and the hippocampus. These findings may be of relevance for the genesis and spread of temporal lobe seizures.

Severe heterotopic ossifications after total knee arthroplasty

The authors report a case of severe heterotopic ossifications after a total knee arthroplasty in an 83-year-old woman. She showed a dramatic loss in range of motion between the third and sixth postoperative week, after she had obtained a satisfactory 0 degree to 90 degrees--range of motion at the 14th postoperative day. A treatment program of radiotherapy combined with indomethacin and nonaggressive antiinflammatory physiotherapy resulted in a slow but steady improvement with complete relief of symptoms 6 months postoperatively.

Glutamate receptor subunits GluR1 and GluR2/3 distribution shows reorganization in the human epileptogenic hippocampus

The AMPA-type glutamate receptor subunits GluR1 and GluR2/3 were localized by immunohistochemistry with subunit-specific antibodies in hippocampi removed surgically from patients with temporal lobe epilepsy for the control of seizures. The flip and flop splice variants of the subunits were localized by in situ hybridization histochemistry with specific oligoprobes. In patient hippocampi that were not the seizure focus, the GluR1 subunit proteins were diffusely expressed on the dendrites of neurons in all regions. In contrast, in these same hippocampi, the GluR2/3 subunit proteins were expressed strongly on the soma and proximal dendrites of principal neurons in all regions. The flip variant of these subunits was localized in the hilus and fields of Ammon's Horn (CA), while the flop variants were prominent on the dentate granule cells. In the epileptogenic hippocampus, while immunoreactivity was decreased in all fields that showed neuronal loss, there was an increased expression of GluR1 on the dendritic excrescences on the proximal dendrites of hilar neurons and CA3 pyramidal neurons, as well as expression of GluR2/3 in hilar neuron excrescences. Electron microscopic examination confirmed that the GluR1 immunoreactivity was only in dendritic processes, particularly dense at the postsynaptic membranes. Such expression of GluR1 may provide for an enhanced glutamatergic response by these neurons. GluR2/3 was also significantly increased on the dendrites of dentate granule cells in the epileptogenic hippocampus and may provide some protection against excitotoxic injury by reducing calcium flux into neurons.

Neuronal damage after the injection of aminooxyacetic acid into the rat entorhinal cortex: a silver impregnation study

In rats, most neurons in layer III of the medial entorhinal cortex are exquisitely vulnerable to prolonged seizure activity. These neurons have also been shown to die preferentially in the entorhinal cortex of patients with temporal lobe epilepsy. This lesion can be duplicated in rats by a focal injection of the indirect excitotoxin aminooxyacetic acid into the entorhinal cortex. The present study was designed to examine the neuropathological consequences of an intra-entorhinal aminooxyacetic acid injection at various time-points with a sensitive silver staining method for the visualization of damaged neurons. After 3 h, affected cells with prominently stained processes were readily observed in the transition zone of the hippocampal CA1 field and the subiculum, but no silver-stained neurons were seen in the entorhinal cortex. Less consistently, damaged neurons were observed in the presubiculum, in the temporal and perirhinal cortices and in the lateral amygdaloid nucleus. At 6 h after an aminooxyacetic acid injection, numerous silver-stained neurons, which were typically devoid of processes, were also seen in layer III of the medial entorhinal cortex. This pattern of neurodegeneration remained similar at 12 and 24 h following the aminooxyacetic acid injection, though many silver-stained neurons were noted in layer II of the lateral entorhinal cortex as well. Notably, at five days, silver-stained neurons had disappeared. Instead, dendritic arbors, debris of degenerated neurons and reactive glial cells were present in lesioned brain regions. These data demonstrate the chronology and the extent of neuronal damage following an intra-entorhinal injection of aminooxyacetic acid. The results suggest that a detailed examination of the temporal sequence of neuronal death in the entorhinal cortex and in extra-entorhinal areas is likely to benefit our understanding of the pathophysiology of temporal lobe epilepsy.

Sleep/waking effects of a selective 5-HT1A receptor agonist given systemically as well as perfused in the dorsal raphe nucleus in rats

Sleep/waking stages and behavior were studied following the selective 5-HT1A agonist 8-OH-DPAT given subcutaneously (s.c.) (0.010-0.375 mg/kg) as well as perfused continuously (10 microM) for 6 h into the dorsal raphe nucleus (DRN) using microdialysis. Given systemically, 8-OH-DPAT at 0.375 mg/kg s.c. induced 5-HT behavioral syndrome, increased waking to 149% and reduced slow wave sleep (SWS) to 86%, transition to 76% and rapid eye movement (REM) sleep to 73%. The effect on deep SWS (SWS-2) was biphasic, with an increase after 2 h. 8-OH-DPAT at 0.010 mg/kg did not have any vigilance effects. 8-OH-DPAT perfusion in DRN produced a fourfold increase in REM sleep compared to perfusion of artificial cerebrospinal fluid. This is consistent with the hypothesis that reduced 5-HT neurotransmission following 5-HT1A autoreceptor stimulation will disinhibit cholinergic REM-promoting mesopontine neurons and thereby lead to a REM sleep increase. The other sleep/waking stages were not significantly affected by 8-OH-DPAT perfusion in DRN.

Simultaneous monitoring of head-to-cervix forces, intrauterine pressure and cervical dilatation during labour

In many westernized countries, the caesarean section role has now reached 15% or more, most commonly because of slow progress in labour. In order for labour to result in a vaginal delivery, the uterine cervix must dilate to allow the foetus to travel through the birth canal. This process is driven by uterine contractions, but the mechanisms by which the contractions result in cervical dilatation are still far from clear. The force exerted by the presenting part (foetal head) on the cervical tissue during contractions (head-to-cervix force, HCF) has been shown to be the variable with the best correlation with cervical dilatation. Unfortunately, the mechanism by which these two variables are related is still poorly understood. In order to investigate the relationship between head-to-cervix force, intrauterine pressure (IUP) and cervical dilatation, we have developed a system for their simultaneous and continuous monitoring during labour. The HCF is measured by using a novel intrauterine probe which is slipped alongside the foetal head so as to lie sandwiched between the latter and the cervix. The probe is fitted with six specially designed miniature force sensors, spaced 1.8 cm apart, which respond linearly and approximate the behaviour of load cells. They are interfaced with a PC by circuitry that allows auto-zeroing and drift compensation. The system enables simultaneous acquisition of intrauterine pressure and foetal heart rate (measured using a Sonicaid Meridian foetal monitor) via a serial link, together with continuous cervical dilatation measured by a caliper-like device applied to the cervix. Some preliminary data are presented, which suggest that the system can be used to investigate the role played by head-to-cervix force and intrauterine pressure in the cervix dilatation process.

Afferents to the seizure-sensitive neurons in layer III of the medial entorhinal area: a tracing study in the rat

Neurons in layer III of the medial entorhinal area (MEA) in the rat are extremely vulnerable to local injections of amino-oxyacetic acid and to experimentally induced limbic seizures. A comparable specific pathology has been noted in surgical specimens from patients with temporal lobe epilepsy. Efforts to understand this preferential neuronal vulnerability led us to study the neural input to this layer in the rat. Iontophoretic injection of the retrograde tracer fast blue, aimed at layer III of the MEA, resulted in retrogradely labeled neurons in the presubiculum in all the injected hemispheres. The nucleus reuniens thalami, the anteromedial thalamic nucleus, the ventral portion of the claustrum (endopiriform nucleus), the dorsomedial parts of the anteroventral thalamic nucleus, and the septum-diagonal band complex were labeled less frequently. In only one experiment, retrogradely labeled neurons were observed in the ventrolateral hypothalamus and in the brainstem nucleus raphe dorsalis. Since projections from claustrum to the entorhinal cortex has not been studied in the rat with modern sensitive anterograde tracing techniques, iontophoretic injections of the anterograde tracer Phaseolus vulgaris-leucoagglutinin were placed into the ventral portion of the claustrum. Anterogradely labeled fibers in the entorhinal area proved not to be confined to the MEA, since a prominent projection distributed to the lateral entorhinal area as well. In both areas, the densest terminal labeling was present in layers IV-VI, whereas layer III appeared to be only sparsely labeled. The present data indicate that of all potential afferents only those from the presubiculum distribute preferentially to layer III of the MEA. This, in turn, suggests a potentially important role of the presubiculum in the seizure-related degeneration of neurons in layer III of the MEA.

Preferential neuronal loss in layer III of the medial entorhinal cortex in rat models of temporal lobe epilepsy

We recently described a pronounced neuronal loss in layer III of the entorhinal cortex (EC) in patients with intractable temporal lobe epilepsy (Du et al., 1993a). To explore the pathophysiology underlying this distinct neuropathology, we examined the EC in three established rat models of epilepsy using Nissl staining and parvalbumin immunohistochemistry. Adult male rats were either electrically stimulated in the ventral hippocampus for 90 min or injected with kainic acid or lithium/pilocarpine. Animals were observed for behavioral changes for up to 6 hr and were killed 24 hr or 4 weeks after the experimental treatments. At 24 hr, all animals that had exhibited a bout of acute status epilepticus showed a consistent pattern of neuronal loss in the EC in Nissl-stained sections. Neurodegeneration was most pronounced in layer III of the medial Ec at all dorsoventral levels. A few surviving neurons were frequently present in the lesioned area. An identical pattern of nerve cell loss was also seen in the EC of rats killed 4 weeks following the treatments. This lesion was completely prevented by an injection of diazepam and pentobarbital, given 1 hr after kainic acid administration. Immunohistochemistry demonstrated a relative resistance of parvalbumin-positive neurons in layer III of the medial EC. Taken together, these experiments indicate that prolonged seizures cause a preferential neuronal loss in layer III of the medial EC and that this lesion may be related to a pathological elevation of intracellular calcium ion concentrations.

Differential neuronal vulnerability to amino-oxyacetate and quinolinate in the rat parahippocampal region

Injection of the "indirect" excitotoxin amino-oxyacetate into the entorhinal area causes acute behavioral seizures and preferential neuronal loss in layer III of the medial entorhinal cortex in rats. We examined here whether the effects of amino-oxyacetate could be duplicated by local injections of the endogenous N-methyl-D-aspartate receptor agonist and direct excitotoxin, quinolinate. Amino-oxyacetate (685 nmol) or quinolinate (30, 45 or 60 nmol) were injected into the entorhinal cortex of rats anesthetized with choral hydrate (360 mg/kg). Separate groups of animals were co-treated with the N-methyl-D-aspartate receptor antagonist dizocilpine maleate (2 mg/kg) or given a higher dose of chloral hydrate (500 mg/kg). Rats that received amino-oxyacetate and a low anesthetic dose consistently displayed acute behavioral seizures and showed preferential loss of neurons in layer III of the medial entorhinal cortex. Animals that were given quinolinate did not display behavioral seizures, and showed preferential degeneration of neurons in layer V of the entorhinal cortex. Moreover, quinolinate-injected rats frequently exhibited neuronal loss in the superficial layers of the dorsal perirhinal cortex. The behavioral and neuropathological sequelae of amino-oxyacetate, but not quinolinate-induced neurotoxicity, were abolished by prolonged chloral hydrate anesthesia. In spite of these apparent qualitative differences between the two toxins, neurodegeneration induced by either amino-oxyacetate or quinolinate was completely prevented by dizocilpine maleate. These data suggest that a heterogeneous distribution of pharmacologically distinct N-methyl-D-aspartate receptor subtypes in the parahippocampal region may underlie the distinct neurodegenerative properties of the two toxins. Since the lesion caused by amino-oxyacetate bears remarkable similarities to neuropathological changes which have been described in this structure in temporal lobe epilepsy, further elucidation of the mechanisms of cellular toxicity of amino-oxyacetate may hold clues for the pathogenesis of this disease.

The use of hydrophobic adhesive tape to produce miniature wells on microscope slides

Hydrophobic adhesive tape was used to produce miniature wells on microscope slides for staining several sections of tissue with minimal amounts of cytochemical reagents. The wells could be tailored to individual specifications and the method allowed coverslips to be mounted close to the sections using either aqueous or xylene based mounting media. This method was especially useful for multiple immunolabelling of serial semithin cryosections.