Thalamocortical dysrhythmia and the thalamic reticular nucleus in behaving rats

OBJECTIVES

The aim of this study was to investigate the effects of bilateral chemical lesion of the rostral pole of the thalamic reticular nucleus on EEG activities in freely moving rats applying quantitative analysis and brain mapping of power spectra distribution.

METHODS

Ketamine-sedated Sprague-Dawley rats were implanted to monitor behavioral states with frontoparietal electrodes in a first series of experiments and with multiple electrodes along the antero-posterior axis (F1, F2, F7, F8, T3, T4, P3, P4) in a second series. Monopolar and bipolar recordings were obtained in animals stereotaxically injected with ibotenic acid into both rostral poles of the thalamic reticular nucleus. Long-term video-EEG recordings and brain mapping based on quantitative spectral analysis were made.

RESULTS

Two forms of dysrhythmia gradually emerged in the neocortical EEG at 12-24h post-injection: potentiation of theta waves and spontaneous high-voltage spindles (HVS) at 4.5-8Hz frequency. Brain mapping during these dysrhythmia shows highest power posteriorly (parietotemporal) for theta and mesiofrontally for HVS.

CONCLUSIONS

Given the lack of inhibitory intrinsic interneurons in the rat thalamus, bilateral destruction of a small part of the solely GABAergic population may promote cortical dysrhythmia (probably by dis-inhibition). The topographic differences in power might indicate different involved structures.

Abolition of the neocortically monitored theta rhythm after ibotenic acid lesion of the parafascicular nucleus in behaving rats

Seven adult Sprague-Dawley rats, chronically implanted with standard electrodes to monitor frontoparietal electroencephalographic (EEG) and nuchal electromyographic (EMG) activity, received, under deep anesthesia, unilateral or bilateral microinjections of ibotenic acid in the lateral part of the parafascicular nucleus of the thalamus. Four days after the injections (corresponding to the period of neuronal destruction), obliteration of the oscillatory activity in the theta range was found on the side ipsilateral to the injection, while on the intact hemisphere the rhythm was well developed. The asymmetry between the two hemispheres was particularly evident during REM sleep but was also seen during attentive but immobile alertness. In bilaterally injected rats, the neocortical theta rhythm was abolished on both hemispheres. These results suggest that in freely-moving rats the lateral parafasciculus neurons are part of the network on which the emergence of the theta rhythm relies.

Solitary breast metastases from a renal cell carcinoma

A case of solitary and metachronous breast metastases from a renal cell carcinoma is described nine years after surgery. The review of the literature proves that the breast is an unusual site for metastatic disease.

Effect of pregnancy on overall survival after the diagnosis of early-stage breast cancer

PURPOSE

To evaluate the impact of subsequent pregnancy on the prognosis of patients with early breast cancer.

PATIENTS AND METHODS

One hundred eight patients who became pregnant after diagnosis of early-stage breast cancer were identified in institutions participating in International Breast Cancer Study Group (IBCSG) studies. Fourteen had relapse of breast cancer before their first subsequent pregnancy. The remaining 94 patients (including eight who relapsed during pregnancy) formed the study group reported here. A comparison group of 188 was obtained by randomly selecting two patients, matched for nodal status, tumor size, age, and year of diagnosis from the IBCSG database, who were free of relapse for at least as long as the time between breast cancer diagnosis and completion of pregnancy for each pregnant patient. Survival comparison used Cox proportional hazards regression models.

RESULTS

Overall 5- and 10-year survival percentages (+/- SE) measured from the diagnosis of early-stage breast cancer among the 94 study group patients were 92% +/- 3% and 86% +/- 4%, respectively. For the matched comparison group survival was 85% +/- 3% at 5 years and 74% +/- 4% at 10 years (risk ratio, 0.44; 95% confidence interval, 0.21 to 0.96; P =.04).

CONCLUSION

Subsequent pregnancy does not adversely affect the prognosis of early-stage breast cancer. The superior survival seen in this and other controlled series may merely reflect a healthy patient selection bias, but is also consistent with an antitumor effect of the pregnancy.

Cisplatin, dacarbazine, and fotemustine plus interferon alpha in patients with advanced malignant melanoma. A multicenter phase II study of the Italian Cooperative Oncology Group

BACKGROUND

In a previous study, the authors tested the combination of fotemustine (FM) 100 mg/m(2) intravenously (i.v.) on Day 1, dacarbazine (DTIC) 250 mg/m(2) i.v. on Days 2-5, and interferon alpha (IFNalpha) 3 MIU intramuscularly three times per week in 43 patients with advanced melanoma. An overall response rate of 40% and a median survival of 40 weeks were obtained. To evaluate whether the addition of cisplatin (CDDP) to this regimen could improve these results, the authors conducted a preliminary Phase I study and concluded that CDDP 25 mg/m(2) i.v. for 2 days can be combined safely with DTIC, FM, and IFNalpha. Herein, the authors report the results of a Phase II trial with this regimen.

METHODS

From June 1996 to February 1999, 64 patients with metastatic melanoma who were not amenable to surgery were enrolled in this study. Sixty eligible patients (32 males and 28 females; median age, 53 years) were treated with a combination of FM 100 mg/m(2) i.v. on Day 1, DTIC 300 mg/m(2) i.v. on Days 2-4, and CDDP 25 mg/m(2) i.v. on Days 3 and 4 recycled every 3 weeks. IFN alpha2b was administered at a dose of 3 MIU intramuscularly 3 times per week until disease progression.

RESULTS

A total of 189 courses were administered, with a median number of 3 courses per patient (range, 1-8 courses per patient). Eleven complete responses and 12 partial responses were observed, for an overall response rate of 38.3% (95% exact confidence interval, 26.1-51.8%). The median survival was 36 weeks. Neutropenia and thrombocytopenia affected 85% of patients and 68% patients and was World Health Organization Grade 3-4 in 40% and 50%, respectively. The side effects attributable to IFN alpha2b were mild and manageable. The other side effects were moderate and well controlled by supportive therapy.

CONCLUSIONS

The schedule used in this study demonstrated significant activity in patients with advanced, untreated melanoma. The addition of CDDP in the management of the patients in this series seemed to increase significantly both the proportion of patients who achieved a complete response and the probability of long term survival compared with a previous series of patients who were treated by the authors. However, considering the currently available therapies, this regimen does not seem to offer a special advantage in the treatment of patients with this disease. New agents and new protocols are needed.

Effects of bilateral microinjections of ibotenic acid in the thalamic reticular nucleus on delta oscillations and sleep in freely-moving rats

The thalamic reticular nucleus (NRT) consists of a large pool of GABAergic neurons located on each side on the anterior, lateral, and ventral surfaces of the dorsal thalamus. The NRT is divided up into sectors. The aim of this study was to investigate the effects of bilateral lesions of the NRT on sleep and sleep oscillations. Only the results concerning delta oscillations will be reported here. As a first step we produced stereotaxically placed electrolytic lesions. The rats presented continuous circling behavior with electroencephalographic (EEG) theta and delta activity and subsequent sudden death. To avoid disruption of the bundles of fibers that pass through the NRT to and from the cerebral cortex, we used the excitotoxic ibotenic acid. Given its high toxicity, we concentrated on the rostral pole of the NRT, which is believed to have powerful effects on the synchronization of oscillatory activity during sleep. Immediately after surgery, the rats fell into a deep sleep during which there was an increase in EEG slow-wave activity and no spindles. On postoperative day 2, corresponding to the destruction period, the sleep/wake cycle partially recovered, but NREM sleep was quantitatively diminished and showed abnormalities (increased latency to sleep onset, sleep fragmentation, gradual elimination of the delta rhythm). It is concluded that the rostral pole of the NRT contributes to normal and pathological EEG synchronization and the organization of sleep in rats.

Methadone dose and retention during treatment of heroin addicts with Axis I psychiatric comorbidity

We studied 90 opioid-dependent subjects, 38 with one or more additional Axis I diagnosis and 52 with no psychiatric comorbidity. There were significant differences between these two groups regarding the methadone dose required for clinical stabilization, but not in the rate of retention in treatment. Dual Diagnosis patients, those with psychiatric comorbidity, required an average stabilization dose of 154 +/- 84 of methadone compared to 99 +/- 49 mg/day for patients whose only Axis I diagnosis was Opioid Dependence. In the 990-day period considered there were no differences between the two groups of patients in terms of retention in treatment.

Early start of adjuvant chemotherapy may improve treatment outcome for premenopausal breast cancer patients with tumors not expressing estrogen receptors. The International Breast Cancer Study Group

PURPOSE

The proper time to commence adjuvant chemotherapy after primary surgery for breast cancer is unknown. An analysis of the International (Ludwig) Breast Cancer Study Group (IBCSG) Trial V at a median follow-up of 11 years suggested that early initiation of adjuvant chemotherapy might improve outcome for premenopausal, node-positive patients whose tumors did not express any estrogen receptor (ER).

PATIENTS AND METHODS

We investigated the relationship between early initiation of adjuvant chemotherapy, ER status, and prognosis in 1,788 premenopausal, node-positive patients treated on IBCSG trials I, II, and VI. The disease-free survival for 599 patients (84 with ER-absent tumors) who commenced adjuvant chemotherapy within 20 days (early initiation) was compared with the disease-free survival for 1,189 patients (142 with ER-absent tumors) who started chemotherapy 21 to 86 days after surgery (conventional initiation). The median follow-up was 7.7 years.

RESULTS

Among patients with ER-absent tumors, the 10-year disease-free survival was 60% for the early initiation group compared with 34% for the conventional initiation group (226 patients; hazard ratio [HR], 0. 49; 95% confidence interval [CI], 0.33 to 0.72; P =.0003). This difference remained statistically significant in a Cox multiple regression analysis controlling for study group, number of positive nodes, tumor size, age, vessel invasion, and institution (HR, 0.60; 95% CI, 0.39 to 0.92; P =.019). Conversely, early initiation of chemotherapy did not significantly improve disease-free survival for patients with tumors expressing ER (1,562 patients; multiple regression HR, 0.93; 95% CI, 0.79 to 1.10; P =.40).

CONCLUSION

In premenopausal patients with ER-absent tumors, early initiation of systemic chemotherapy after primary surgery might improve outcome. Further confirmatory studies are required before any widespread modification of current clinical practice. In premenopausal patients with tumors expressing some ER, gains from early initiation are unlikely to be clinically significant.

Intraoperative and percutaneous radiofrequency thermal ablation in the treatment of hepatocellular carcinoma

AIMS AND BACKGROUND

The aim of the study was to evaluate feasibility, survival rate, complications and length of hospital stay in 47 patients with hepatocellular carcinoma (HCC) treated by radiofrequency thermal ablation (RFTA). Though the treatment of choice for HCC is surgical resection, the strong association of this disease with cirrhosis often rules out this procedure. Many investigations have been conducted in order to identify alternative therapies. Preliminary studies of radiofrequency thermal ablation have shown that the technique is effective and safe, achieving a predictable area of tumor tissue coagulative necrosis and sparing the surrounding cirrhotic parenchyma, without any significant side effects. In addition, this technique, which can be performed percutaneously, allows very short hospital stays.

PATIENTS AND METHODS

We report the results of a series of 47 cirrhotic patients with 52 HCC nodules (mean diameter 2.9 cm, range 1-6 cm) treated in our Institute between May 1997 and June 1999 by RFTA using an expandable needle with four hooks at its tip. All patients had hepatic cirrhosis (32 Child A, 13 Child B and two Child C). We treated patients with both unifocal (35 patients) and multifocal HCC (12 patients); 33 patients underwent percutaneous RFTA (54 passes), while in 14 cases RFTA was performed during laparotomy (22 passes).

RESULTS

The mean number of passes to achieve complete necrosis was 1.43 in 28 patients with unifocal HCC treated by percutaneous RFTA, 1.7 in 7 patients with unifocal HCC treated by intraoperative RFTA, 2.8 in 5 patients with multifocal HCC treated by percutaneous RFTA and 1.43 in 7 patients with multifocal HCC treated by intraoperative RFTA. No deaths related to the procedure or major complications occurred. Post-treatment dynamic CT was performed in all patients. All patients but one were followed-up for a mean period of 11.8 months (1-25 months). Six patients died during the follow-up (three Child A, two Child B and one Child C. The actuarial survival, computed by the Kaplan-Meier method, was 83% at 24 months. The mean hospital stay was 3.4 days in patients treated by percutaneous RFTA and 11.2 days in those treated by intraoperative RFTA.

CONCLUSIONS

In our opinion RFTA is an effective, safe technique capable of achieving good results in the conservative therapy of small HCC. We believe that curative ablation is possible for HCC nodules measuring up to 3 cm in diameter. Further studies of longer duration are necessary.

Descending projections arising from the parafascicular nucleus in rats: trajectory of fibers, projection pattern and mapping of terminations

The organization of the descending projections from the intralaminar parafascicular nucleus was studied using biocytin as an anterograde tracer in rats. After biocytin injection into the lateral parafascicular nucleus, three bundles of fibers descending throughout the brainstem were seen. Terminal fields were found in several structures, for example the lateral geniculate nucleus, nucleus reticularis thalami, subthalamus, zona incerta, substantia nigra, red nucleus, periaqueductal gray, superior colliculus, reticular formation, raphe nuclei, pontine nuclei, trigeminal complex, and ventral horn of the spinal cord. Different types of labeled terminals (small terminal boutons, en passant varicosities, large claw-like terminals) were observed, particularly in the substantia nigra and reticular formation where the density of terminals was highest. The organization of these extensive descending connections to both motor and sensory structures does not allow functions to be conclusively attributed to the parafascicular nucleus neurons. Further investigations are required to resolve this question.

Factors affecting baseline quality of life in two international adjuvant breast cancer trials. International Breast Cancer Study Group (IBCSG)

Quality of life (QL) is used to assess treatments in clinical trials but may be influenced by other factors. We analysed the impact of biomedical, sociodemographic and cultural factors on baseline QL indicators in two International Breast Cancer Study Group trials. Patients with stage II breast cancer were randomized within 6 weeks of primary surgery to various adjuvant treatments. They were asked to assess five indicators of QL at baseline. QL forms were available for 1231 (83%) of the 1475 premenopausal and 989 (82%) of the 1212 post-menopausal patients, who were from nine countries and spoke seven languages. Culture (defined as language/country groups) had a statistically significant impact on baseline QL measures. Premenopausal patients with poor prognostic factors showed a tendency to report worse QL, with oestrogen receptor status as an independent predictor for mood (P = 0.0005). Older post-menopausal patients reported better emotional wellbeing (P = 0.002), mood (P = 0.002), and less effort to cope (P = 0.0009) compared with younger post-menopausal patients. Co-morbidity, type of surgery, treatment assignment and sociodemographic factors showed a statistically significant impact in post-menopausal patients only. Cultural and biomedical factors influenced baseline QL and should be considered when evaluating the impact of treatment on QL in international breast cancer clinical trials.

[Hydrocephalus and rebleeding in subarachnoid hemorrhage]

The main features of rebleeding and post-haemorrhagic hydrocephalus in case of subarachnoid haemorrhage following the rupture of an intracranial aneurysm are presented. In both cases frequency, causes, clinical events, prevention and therapy are discussed.

Cisplatin, etoposide and bleomycin infusion (PEBi regimen) in good-risk patients with germ cell tumors

Patients with good-risk germ cell tumors have an approximately 85-95% chance of cure with standard chemotherapy. However, acute and late toxicity may be severe and negatively influence the quality of life. In an attempt to reduce toxicity, we evaluated a new schedule including bleomycin administered-as a continuous infusion in patients with low and intermediate volume metastatic disease. Patients were treated as follows: cisplatin, 100 mg/m(2) day 4; etoposide, 100 mg/m(2) days 1 through 5; bleomycin, 15 unit bolus on day 1 followed by 30 mg as a continuous infusion for 72 h, with cycles repeated every 21 days. Between 1992 and 1996, 25 patients entered the study and were assessable for response and side effects. Major patient characteristics were: performance status ECOG 0-1; minimal disease, 13 patients, intermediate disease, 12; median age, 33 years (range 15-50). Twenty-one of 25 patients (84%) achieved a complete remission, 2 patients achieved a partial remission, and 2 patients did not respond to the regimen. At a median follow-up of 24 months, 24/25 patients were alive, 23 were without evidence of disease, and I had persistent disease. Grade III/IV side effects included leuko/neutropenia (8 patients), anemia (3 patients), and nausea/vomiting (3 patients). No drug-related deaths were observed, and no evidence of pulmonary toxicity was registered. In conclusion, the PEBi regimen is an effective and well-tolerated regimen in patients with good-risk germ cell tumors and may be considered as a front-line chemotherapy.

Paclitaxel, ifosfamide, and carboplatin for the treatment of stages IIIB and IV non-small cell lung cancer: preliminary results

We have treated 26 consecutive chemotherapy-naive patients with stage IIIB/IV non-small cell lung cancer with an innovative regimen based on a 1-hour infusion of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) 125 to 250 mg/m2, ifosfamide 3 g/m2 (with mesna), and carboplatin dosed to an area under the concentration-time curve of 5, every 21 days for a total of six cycles in responding or stabilized patients. Among 22 fully evaluable patients, 14 (64%) achieved a partial remission, six had disease stabilization, and two had disease progression. Hematologic toxicity was remarkably mild; only one patient had grade 3 neutropenia (on day 21). Arthralgias/myalgias (grade 3 in nine patients, grade 4 in one patient) and neurologic toxicity (a cumulative sensory neuropathy of grade 3 or 4 in five patients) were the most common side effects and seem to be dose related. To date, few patients are fully evaluable and survival data are clearly immature. Nevertheless, this regimen seems highly active and quite well tolerated, and deserves further evaluation.

High-dose chemotherapy with autologous stem cell transplantation is feasible and safe in a regional hospital. A 6-year experience in southern Switzerland

High-dose therapy with bone marrow (BM) or blood stem cell (BSC) support is a high-technology technique usually administered in specialized tertiary centers. The use of BSC has made this technique simpler and accessible also to smaller hospitals. We retrospectively analyzed the data of patients with lymphoma, leukemia and other tumors who received high-dose therapy and BM or BSC transplantation in our district hospital, looking at the type of procedure performed, complications, use of growth factors, and progression-free and overall survival. A total of 40 patients were transplanted over 6 years. No procedure-related deaths and no permanent organ toxicities were seen. The use of BSC brought about a great reduction in the duration of hospital stay, septic complications and transfusion of blood components. For patients with lymphoma (n = 20) the probabilities of progression-free survival and of overall survival at 2 years are 48% (95% C.I. 28-68%) and 68% (95% C.I. 46-84%), respectively. Based on these data, we believe that ABMT and BSC transplantation are feasible and safe in a peripheral hospital when the appropriate human and technical conditions are present. Treatment outcome is then comparable to that of specialized centers.

Characterization of a cytogenetic 17q11.2 deletion in an NF1 patient with a contiguous gene syndrome

We report on a rare patient screened as a putative carrier of a contiguous gene syndrome on the basis of a complex phenotype characterized by sporadic neurofibromatosis type 1 (NF1), dysmorphism, mental retardation and severe skeletal anomalies. A cytogenetically visible 17q11.2 deletion was detected in the patient's karyotype by high-resolution banding and confirmed by fluorescence in situ hybridization with yeast artificial chromosomes targeting the NF1 region. Analysis of the segregation from parents to proband of 13 polymorphic DNA markers, either contiguous or contained within the NF1 gene, showed that the patient is hemizygous at sites within the NF1 gene-the AAAT-Alu repeat in the 5' region of intron 27b, the CA/GT microsatellite in the 3' region of intron 27b, and the CA/GT microsatellite in intron 38- and at the extragenic D17S798 locus, distal to the 3' end of NF1. The patient may be an important resource in the identification of genes downstream of NF1 that may contribute to some of his extra-NF1 clinical signs.

Low-dose continuous intravenous infusion of 5-fluorouracil for metastatic breast cancer

BACKGROUND

Third-line chemotherapies for advanced breast cancer are difficult to tailor to the individual patient because of reduced tolerance and significant toxicity. Treatment with a continuous intravenous infusion of low-dose 5-fluorouracil (FU-LDCI) is generally well tolerated and thus, a reasonable option for heavily pretreated patients.

PATIENTS AND METHODS

From 1989 to 1995, 106 consecutive patients with advanced breast cancer were treated with FU-LDCI. 5-Fluorouracil was given at an initial daily dose of 250 mg/m2 administered continuously with the aid of an elastomer, non-electronic pump through a permanent central venous line for 21 days followed by a 7-day rest. The median age was 56 years (range, 30-82), the median ECOG Performance Status was 1 (range 0-4) and the median number of metastatic sites was 2 (range 1-4). Sixty-one percent of the patients had previously received more than 2 chemotherapy regimens which in 81% included adriamycin, and in 90% 5-fluorouracil.

RESULTS

Eighty patients were evaluable for objective response: 17 of them had partial responses (21%, 95% CI: 14%-31%) and 23 stable disease (29%, 95% CI: 20%-40%). One-hundred five patients were evaluable for subjective response, with 46 reporting improvement (44%, 95% CI: 35%-54%). Previous treatments with either 5-fluorouracil or adriamycin did not predict response to FU-LDCI. Median time to progression for patients with a partial response or stable disease was 259 days (range 82-737). The overall survival for the populations as a whole was 274 days (range 13-2264), and the median dose received was 1904 mg/week (range 753-4329). The main toxic effects were grades I and II mucositis, and nausea and vomiting (observed in 31% and 28%, respectively). Grade III toxicities were uncommon: mucositis in 3%, nausea and vomiting in 3%, anemia, thrombocytopenia and hepatitis in 2%, and skin toxicity (hand-foot syndrome) in 1%. Catheter-related thrombosis was observed in 2% of the patients, and there were no pump failures. A questionnaire concerning the impact of the treatment upon quality of life was completed by all of the 13 patients who were alive at the time of evaluation of the results, and all of them rated FU-LDCI as easy to tolerate. The monthly cost of FU-LDCI (US$1,051.00 in Switzerland) was lower than the cost of weekly low-dose adriamycin (US$1,483.00 in Switzerland), a treatment which is often used as a palliative regimen in similar circumstances.

CONCLUSION

FU-LDCI is a useful, cost-effective third-line treatment for patients with metastatic breast cancer who need palliation with cytotoxic drugs.

Histopathological grading of response to induction chemotherapy in non-small cell lung cancer: a preliminary study

Management of locally advanced NSCLC is controversial. Induction chemotherapy followed by surgery has become an accepted approach for Stage III disease. However, the clinical assessment of the efficacy of preoperative treatment is inaccurate. We propose a four-grade histopathological evaluation of the response to chemotherapy based on the analysis of 20 evaluable cases and compared with clinical outcome. Follow-up ranged from 12 to 68 months. Correlation between different grading of necrosis and survival is statistically significant. Based on these preliminary results, we suggest that grading of response is a valid parameter to evaluate standard regimens and novel drug associations in larger trials.