Critical decline in fine motor hand movements in human aging

BACKGROUND

Slowing of motor movements in human aging is a well-known occurrence, but its biologic basis is poorly understood. Reliable quantitation may refine observations of this phenomenon to better aid research on this entity.

METHODS

A panel equipped with timing sensors under computer control was used to measure upper extremity movement times in two groups of healthy individuals: adults younger than 60 years of age (n = 56; range, 18-58 years) and adults older than 60 years of age (n = 38; range, 61-94 years).

RESULTS

Fine motor performance was better in the dominant hand (p = 0.0007) regardless of age. Adult and aged groups differed on two basic timing measures, which reflect coarse motor and fine motor performance (p < 0.0001). There were no gender differences on either measure. There was a strong effect of task difficulty with age on coarse motor (p < 0.01) and fine motor (p < 0.0001) measures. The fine motor measure of hand performance in healthy individuals correlated in a nonlinear fashion with age for more difficult tasks (r2 = 0.63) but showed a simple linear relation for less-demanding tasks (r2 = 0.5).

CONCLUSION

This technique sensitively detects age-related motor performance decline in humans. There may be a critical period in late midlife when fine motor performance decline either begins or abruptly worsens.

Laparoscopic fundoplication failures: patterns of failure and response to fundoplication revision

OBJECTIVE

To determine rates and mechanisms of failure in 857 consecutive patients undergoing laparoscopic fundoplication for gastroesophageal reflux disease or paraesophageal hernia (1991-1998), and compare this population with 100 consecutive patients undergoing fundoplication revision (laparoscopic and open) at the authors' institution during the same period.

SUMMARY BACKGROUND DATA

Gastroesophageal fundoplication performed through a laparotomy or thoracotomy has a failure rate of 9% to 30% and requires revision in most of the patients who have recurrent or new foregut symptoms. The frequency and patterns of failure of laparoscopic fundoplication have not been well studied.

METHODS

All patients undergoing fundoplication revision were included in this study. Symptom severity was scored before and after surgery by patients on a 4-point scale. Evaluation of patients included esophagogastroscopy, barium swallow, esophageal motility, 24-hour ambulatory pH, and gastric emptying studies. Statistical analysis was performed with multiple chi-square analyses, Fisher exact test, and analysis of variance.

RESULTS

Laparoscopic fundoplication was performed in 758 patients for gastroesophageal reflux disease and in 99 for paraesophageal hernia. Median follow-up was 2.5 years. Thirty-one patients (3.5%) have undergone revision for fundoplication failure. The mechanism of failure was transdiaphragmatic herniation of the fundoplication in 26 patients (84%). In 40 patients referred from other institutions, after laparoscopic fundoplication, only 10 (25%) had transdiaphragmatic migration (p < 0.01); a slipped or misplaced fundoplication occurred in 13 patients (32%), and a twisted fundoplication in 12 patients (30%). The failure mechanisms of open fundoplication (29 patients) followed patterns previously described. Fundoplication revision procedures were initiated laparoscopically in 65 patients, with six conversions (8%). The morbidity rate was 4% in laparoscopic procedures and 9% in open ones. There was one death, from aspiration and adult respiratory distress syndrome after open fundoplication. A year or more after revision operation, heartburn, chest pain, and dysphagia were rare or absent in 88%, 78%, and 91%, respectively, after laparoscopic revision, and were rare or absent in 91%, 83%, and 70%, respectively, after open revision, but 11 patients ultimately required additional operations for continued or recurrent symptoms, 3 after open revision (17%), and 8 after laparoscopic fundoplication (11%).

CONCLUSIONS

Laparoscopic fundoplication failure is infrequent in experienced hands; the rate may be further reduced by extensive esophageal mobilization, secure diaphragmatic closure, esophageal lengthening (applied selectively), and avoidance of events leading to increased intraabdominal pressure. When revision is required, laparoscopic access may be used successfully by the laparoscopically experienced esophageal surgeon.

Asthma and gastroesophageal reflux: fundoplication decreases need for systemic corticosteroids

An association between gastroesophageal reflux (GER) and asthma has been suggested for many decades. Although antireflux therapy (medical and surgical) has been shown to be beneficial in patients with asthma, response to therapy has not been well quantified. The aim of this study was to evaluate long-term outcome in patients with asthma and associated GER undergoing fundoplication. From a database of more than 600 patients with GER treated surgically between 1991 and 1996, 39 patients with asthma as their primary indication for surgery were identified. Asthma symptom scores were determined using the National Asthma Education Program classification, and medication frequency scores were determined preoperatively and at latest follow-up (median follow-up 2.7 years). Comparisons were made using the Wilcoxon rank-sum test. Asthma symptom scores decreased significantly after antireflux surgery. More important, the medication scores for use of systemic corticosteroids decreased significantly postoperatively (2.2 preoperatively vs. 0.7 postoperatively; P = 0.0001). Of the nine patients who required daily oral corticosteroids, seven have discontinued treatment entirely (78%). In patients with asthma associated with GER, symptoms of asthma are improved following fundoplication. Especially important has been the ability to wean patients from systemic corticosteroids postoperatively. Fundoplication should be offered to those patients with GER-associated asthma, especially those who are steroid dependent.

Frequency of first metastatic events in breast cancer: implications for sequencing of systemic and local-regional treatment

PURPOSE

The sequencing of treatment for early breast cancer is controversial. The purpose of this study was to quantify the risk of delaying surgery, using estimates of the frequency of first metastases from breast primary tumors.

PATIENTS AND METHODS

The probability that 560 (node-negative), 657 (with one to three positive nodes), and 505 (with more than three positive nodes) women treated without adjuvant chemotherapy would be free of distant disease at presentation was fit to a mathematical model of the seeding of distant metastases and combined with estimates of the growth rate to calculate the frequency of first distant disseminations per month.

RESULTS

Frequencies of first distant metastases were approximately 1% to 2% per month, 2% to 4% per month, and 3% to 6% per month in T1 patients who were node-negative, had one to three positive nodes, or more than three positive nodes, respectively. As a result, the typical patient with T1 disease, who has a 70% to 80% chance of being free of distant disease, runs a 1% to 4% risk of distant dissemination for each month surgery is delayed. Assuming a 30% reduction in mortality caused by adjuvant chemotherapy, the model predicts that T1 patients treated with neoadjuvant chemotherapy would potentially have a higher rate of distant metastasis development than those treated with an initial surgical resection followed by adjuvant chemotherapy.

CONCLUSION

We formulate the hypothesis that optimal sequencing of surgery and systemic treatment of breast cancer may be size-dependent, with a disadvantage or no benefit from neoadjuvant treatment for T1 patients but an increasing benefit with increasing size of the primary tumor.

Fundoplication provides effective and durable symptom relief in patients with Barrett's esophagus

BACKGROUND

Columnar-lined esophagus with intestinal metaplasia (IM), also called Barrett's esophagus, is a manifestation of severe gastroesophageal reflux (GER) and may predict poor symptom relief and high failure rate after fundoplication. We compared symptom scores and reoperation rates in GER patients with and without Barrett's esophagus.

METHODS

Between July 1992 and July 1997, 646 patients underwent fundoplication (626 laparoscopic). Of 150 endoscopic biopsies of suspected columnar-lined esophagus, 80 confirmed IM, 50 identified cardiac or fundic epithelium, and 20 revealed only esophagitis. Typical GER symptoms were scored by patients preoperatively and postoperatively (0 to 4 scale). We compared symptom response (Wilcoxon rank sum test) and failure rates (t test) in patients with IM and GER controls without IM. Preoperative data were available for 74 IM patients and 496 controls. One-year follow-up was available in 45 IM patients and 301 controls. Intermediate follow-up (2 to 5 years) was available in 20 IM patients and 99 controls.

RESULTS

Preoperatively and postoperatively, patients with IM reported heartburn, regurgitation, and dysphagia scores similar to controls. Procedure failure, requiring redo fundoplication, appeared more likely in IM patients than controls (6.3% versus 2.5%), but this difference did not reach statistical significance (P = 0.061).

CONCLUSION

Fundoplication provides equivalent symptom relief for patients with and without IM.

Radiation therapy for clinically localized prostate cancer: a multi-institutional pooled analysis

CONTEXT

Prostate-specific antigen (PSA) evaluation leads to the early detection of both prostate cancer and recurrences following primary treatment. Prostate-specific antigen outcome information on patients 5 or more years following treatment is limited and available mainly as single-institution reports.

OBJECTIVES

To assess the likelihood and durability of tumor control using PSA evaluation 5 or more years after radical external beam radiation therapy and to identify pretreatment prognostic factors in men with early prostate cancer treated since 1988, the PSA era.

DESIGN AND SETTING

Retrospective, nonrandomized, multi-institutional pooled analysis of patients treated with external beam radiation therapy alone between 1988 and 1995 at 6 US medical centers. Follow-up lasted up to a maximum of 9 years. Outcome data were analyzed using Cox regression and recursive partitioning techniques.

PATIENTS

A total of 1765 men with stage T1b, T1c, and T2 tumors treated between 1988 and 1995 with external beam radiation. The majority (58%) of patients were older than 70 years and 24.2% had initial PSA values of 20 ng/mL or higher. A minimum of 2 years of subsequent follow-up was required for participation.

MAIN OUTCOME MEASURE

Actuarial estimates of freedom from biochemical failure.

RESULTS

The 5-year estimates of overall survival, disease-specific survival, and the freedom from biochemical failure are 85.0% (95% confidence interval [CI], 82.5%-87.6%), 95.1% (95% CI, 94.0%-96.2%), and 65.8% (95% CI, 62.8%-68.0%), respectively. The PSA failure-free rates 5 and 7 years after treatment for patients presenting with a PSA of less than 10 ng/mL were 77.8% (95% CI, 74.5%-81.3%), and 72.9% (95% CI, 67.9%-78.2%). Recursive partitioning analysis of initial PSA level, palpation stage, and the Gleason score groupings yielded 4 separate prognostic groups: group 1, included patients with a PSA level of less than 9.2 ng/mL; group 2, PSA level of at least 9.2 but less than 19.7 ng/mL; group 3, PSA level at least 19.7 ng/mL and a Gleason score of 2 to 6; and group 4, PSA level of at least 19.7 ng/mL and a Gleason score of 7 to 10. The estimated rates of survival free of biochemical failure at 5 years are 81 % for group 1, 69% for group 2, 47% for group 3, and 29% for group 4. Of the 302 patients followed up beyond 5 years who were free of biochemical disease, 5.0% relapsed from the fifth to the eighth year.

CONCLUSIONS

Estimated PSA control rates in this pooled analysis are similar to those of single institutions. These rates indicate the probability of success for subsets of patients with tumors of several prognostic category groupings. These results represent a multi-institutional benchmark for evidence-based counseling of prostate cancer patients about radiation treatment.

Laparoscopic insufflation with room air causes exaggerated interleukin-6 response

BACKGROUND

The gut is a central organ in the postoperative stress reaction. We previously reported that measuring gut-mucosal cytokines may more accurately reflect the response to operative stress. Additionally, we have shown that the gut demonstrates a blunted cytokine response after laparoscopy as compared with laparotomy.

METHODS

To further investigate whether this differential response is caused by exposure of the peritoneal cavity to general atmospheric air during laparotomy, 80 A/J mice were randomized equally into four groups: CD (carbon dioxide [CO2] pneumoperitoneum), RA (room air pneumoperitoneum), AP (anesthesia and port insertion only), and PC (pure control, no intervention). Pneumoperitoneum was established and maintained at 3 mmHg for 60 min. All the mice were killed 4 h after the intervention. Jejunal mucosa and serum samples were collected and analyzed for interleukin-6 (IL-6) levels. Results were analyzed by analysis of variance (ANOVA).

RESULTS

Gut-mucosal IL-6 in the RA group was significantly higher than in all other groups: RA, 1,354.5 +/- 117.9* vs. CD, 964.3 +/- 114.0 vs. AP, 960.2 +/- 86.2 vs. PC, 908.0 +/- 83.6; *p < 0.05. The CD group did not show a significant increase in gut-mucosal IL-6 as compared with the AP and PC groups. Similarly, RA resulted in significant increases in serum IL-6 as compared with AP and PC, whereas CD showed no significant difference: RA, 161.3 +/- 66.2* vs. 95.1 +/- 1 vs. AP, 10.6 +/- 5.3 vs. PC, undetectable; *p < 0.05. There was no difference in serum IL-6 level between CD or any of the other groups.

CONCLUSIONS

Exposure of the peritoneal cavity to atmospheric air, independently of the trauma of abdominal access, causes an exaggerated serum and gut mucosal IL-6 response 4 h after intervention. The beneficial effect of CO2 laparoscopy may be caused by the exclusion of general atmospheric air from the peritoneal cavity.

D-dimers in the diagnosis of pulmonary embolism

The aim of this study was to determine if the absence of circulating D-dimers, as determined by latex agglutination assays, can correctly exclude the presence of pulmonary embolism using pulmonary angiography as the diagnostic endpoint. Blood samples were obtained prospectively at the time of angiography for suspicion of acute pulmonary embolism. Plasma was assayed for D-dimer by five different latex agglutination assays. Angiographic evidence of pulmonary emboli was found in 34% (35/ 103) of patients. The latex agglutination assays had sensitivities of 97 to 100% and specificities of 19 to 29%. The negative predictive value was 94 to 100%. However, a negative D-dimer was rare in patients with recent surgery, malignancy, or total bilirubin > 34 micromol/L (> 2 mg/dl). In 31 patients suspected of pulmonary emboli but without these confounding factors, the five D-dimer assays were negative in 46 to 55% of patients with normal pulmonary angiograms. The negative predictive value in these patients was 100% by all five latex agglutination assays tested. The latex agglutination assays for D-dimer, when the pulmonary angiogram is used as the diagnostic endpoint and in the absence of recent surgery, malignancy, or liver disease, appears to be a clinically useful test in the diagnosis of acute pulmonary embolism.

Uncapping and deregulation of telomeres lead to detrimental cellular consequences in yeast

Telomeres are the protein-nucleic acid structures at the ends of eukaryote chromosomes. Tandem repeats of telomeric DNA are templated by the RNA component (TER1) of the ribonucleoprotein telomerase. These repeats are bound by telomere binding proteins, which are thought to interact with other factors to create a higher-order cap complex that stabilizes the chromosome end. In the budding yeast Kluyveromyces lactis, the incorporation of certain mutant DNA sequences into telomeres leads to uncapping of telomeres, manifested by dramatic telomere elongation and increased length heterogeneity (telomere deregulation). Here we show that telomere deregulation leads to enlarged, misshapen "monster" cells with increased DNA content and apparent defects in cell division. However, such deregulated telomeres became stabilized at their elongated lengths upon addition of only a few functionally wild-type telomeric repeats to their ends, after which the frequency of monster cells decreased to wild-type levels. These results provide evidence for the importance of the most terminal repeats at the telomere in maintaining the cap complex essential for normal telomere function. Analysis of uncapped and capped telomeres also show that it is the deregulation resulting from telomere uncapping, rather than excessive telomere length per se, that is associated with DNA aberrations and morphological defects.

Functional magnetic resonance imaging evidence for task-specific activation of developmentally abnormal visual association cortex

Functional magnetic resonance imaging was performed on a 36-year-old woman with muscular dystrophy, intractable epilepsy, and bilateral temporo-occipital lissencephaly. We observed islands of task-specific activation in lissencephalic cortex homologous to visual association regions activated in normal subjects on the same visual confrontation naming task. This result suggests lissencephalic cortex may develop specific functional connections with other brain regions.

Laparoscopic adrenalectomy: new gold standard

Nearly 600 cases of laparoscopic adrenalectomy have been described in the world literature, documenting the safety and effectiveness of the procedure. Comparative studies have demonstrated the advantages of the laparoscopic approach when compared to traditional open approaches to adrenalectomy, documenting a more rapid and comfortable recovery, shorter hospitalization, and fewer complications. Several techniques of laparoscopic adrenalectomy have been described. We prefer the transabdominal approach in the lateral decubitus position. Herein we report our experience with 28 adrenalectomies using this approach. Indications for adrenalectomy have been hyperaldosteronism (9), hypercortisolism (4), pheochromocytoma (3), incidentaloma (6), metastasis (3), lymphoma (1), angiomyolipoma (1), other (1). Average tumor size was 3.3 cm (1. 4-8.3 cm). Average operative time was 152 minutes (110-210 minutes), with left adrenalectomy taking slightly longer to perform than on the right (156 vs. 145 minutes). There were no intraoperative complications and one conversion to open adrenalectomy for a large metastatic lung cancer found to be invading the liver. One patient experienced left rib pain from a cannula site immediately at the costal margin. There were no other complications. Average length of hospitalization was 2.3 days (1-6 days). With this and others' experience, laparoscopic adrenalectomy has become the gold standard for adrenalectomy. This manuscript reviews the literature on laparoscopic adrenalectomy and describes the transabdominal lateral approach.

Fundoplications resist reflux independent of in vivo anatomic relationships

BACKGROUND

Antireflux operations restore lower esophageal sphincter (LES) function and hiatal anatomy; however, the relative contributions are unclear.

METHODS

We measured the competency of fundoplications, exclusive of in vivo variables, in gastroesophageal explants from 8 cadavers. Using a multichannel manometer, esophageal, LES, and intragastric pressures were recorded during transpyloric distension. Data were compared at baseline, and after Nissen (360 degrees) and Toupet (270 degrees) fundoplications.

RESULTS

Before fundoplication, stomachs refluxed immediately upon distension. Nissen fundoplications never refluxed before gastric rupture (46.8 +/- 15.0 mm Hg). LES pressure averaged 2.0 +/- 0.5 times intragastric pressure during distension. Toupet fundoplications refluxed at intragastric pressure <2 mm Hg, then became competent until gastric rupture (49.9 +/- 15.0 mm Hg). LES pressure averaged 2.4 +/- 1.0 times intragastric pressure during distension.

CONCLUSIONS

Nissen and Toupet fundoplications increase LES pressure linearly at 2 to 2.5 times intragastric pressure, independent of in vivo variables. Toupet fundoplication lacks the competency of Nissen fundoplication at low intragastric pressures.

MRI temporal lobe volume measures and neuropsychologic function in Alzheimer's disease

The authors performed quantitation of the temporal lobes using magnetic resonance imaging in 20 patients with mild-to-moderate Alzheimer's disease, 20 age-matched aged control subjects, and 26 healthy young volunteers. Compared to young subjects, aged controls showed volume reductions in amygdala (17%, p = 0.02), hippocampus (15%, p = 0.0001) and temporal lobe (22%, p = 0.0001). Compared to aged controls, Alzheimer's subjects showed further volume reductions in amygdala (33%, p = 0.0001) and hippocampus (20%, p = 0.006) but not temporal lobe (7%, p = 0.15). In Alzheimer's subjects, left temporal lobe volume correlated strongly with the Mini Mental State (MMSE) score (adjusted r2 = 0.46, p = 0.0006) whereas right amygdala volume correlated inversely with the noncognitive ADAS score (adjusted r2 = 0.46, p = 0.0006). The authors conclude that significant volume changes occur in the temporal lobe in aging and in Alzheimer's disease, with the greatest percentage reductions in the amygdala in Alzheimer's disease. Temporal neocortical atrophy and temporal limbic atrophy might be associated with different patterns of performance and behavior in Alzheimer's patients.

New reference allelic ladders to improve allelic designation in a multiplex STR system

This paper reports the composition of a new reference allelic ladder mixture for use with a multiplex DNA profiling system consisting of six short tandem repeat loci. The loci included in this mixture are HUMTH01, D21S11, D18S51, D8S1179, HUMVWAF31/A, HUMFIBRA/FGA and an amelogenin sex test. Sequence analysis of individual ladder alleles was carried out and allelic designations made in accordance with the recommendations of the International Society of Forensic Haemogenetics (1992; 1994). A series of rare alleles which increase the range of alleles previously reported were identified. By including some of the rare alleles into the ladder marker system, we have significantly improved the ability to identify new alleles in unknown samples.

Tolyporphins J and K, two further porphinoid metabolites from the cyanobacterium Tolypothrix nodosa

Two new porphinoids, tolyporphins J (1) and K (2), have been isolated from the terrestrial cyanobacterium, Tolypothrix nodosa (HT-58-2) and identified by NMR and mass spectral analysis. The activities of tolyporphins J and K in cell sensitization and drug accumulation assays for multidrug resistance (MDR) reversal were compared with those of tolyporphin A. Unusual NMR spectroscopic shifts were observed for tolyporphin J (1) in CDCl3.

Tolyporphin: a natural product from cyanobacteria with potent photosensitizing activity against tumor cells in vitro and in vivo

Tolyporphin (TP), a porphyrin extracted from cyanobacteria, was found to be a very potent photosensitizer of EMT-6 tumor cells grown both in vitro as suspensions or monolayers and in vivo in tumors implanted on the backs of C.B17/Icr severe combined immunodeficient mice. Thus, during photodynamic treatment (PDT) of EMT-6 tumor cells in vitro, the photokilling effectiveness of TP measured as the product of the reciprocal of D50 (the light dose necessary to kill 50% of cells) and the concentration of TP is approximately 5000 times higher than that of Photofrin II (PII), the only PDT photosensitizer thus far approved for clinical trials. TP almost exclusively localizes in the perinuclear region and specifically in the endoplasmic reticulum (ER), as shown by microspectrofluorometry on single living EMT-6 cells costained with the ER and/or Golgi fluorescent vital probes, 3,3'-dihexyloxacarbocyanine iodide and N-[4,4-difluoro-(5,7-dimethyl-BODIPY)-1-pentanoyl]-D-erythro-sphin gosine (Molecular Probes, Eugene, OR). As a result, the singlet oxygen-mediated photodynamic activity of TP induces an effective inactivation of the acyl CoA:cholesterol-O-acyltransferase, a sensitive marker of ER membrane integrity and alterations of the nuclear membrane. In vivo, with the EMT-6 mouse tumor model, an exceptional effectiveness is also observed as compared to that of PII and other second generation photosensitizers of the pheophorbide class, which are themselves much more potent than PII. The outstanding PDT activity of TP observed in vivo may be due to its unique biodistribution properties, in particular much less extraction by the liver, resulting in a higher delivery to other tissues, including tumor.

Neural lesions in the rat and their relationship to EEG delta activity following seizures induced by the nerve agent soman

This study describes the neural structures damaged following exposure to the nerve agent soman, shows there are time-dependent differences in the extent of damage in certain structures, and relates seizure-induced increases in delta band (0-3.5 Hz) electroencephalographic (EEG) activity with severity of subsequent neuropathology. Rats, instrumented to record cortical EEG activity, were pretreated with the oxime HI-6 (125 mg/kg, i.p.) and then challenged with soman (180 ug/kg, s.c.). All animals developed continuous epileptiform seizures that lasted in excess of 4 hr. Groups of animals were perfused 1, 3, 10 or 30 days following exposure. Paraffin-embedded brains were stained with hematoxylin and eosin; thirty-four neural structures were examined and scored for neural damage. All cortical areas sustained damage, with piriform and perirhinal cortices exhibiting the most severe. Subcortical limbic areas (amygdala, amygdala-piriform transition zone, hippocampus, claustrum) and various thalamic nuclei were most consistently and severely damaged in all animals regardless of survival time. Brainstem structures, cerebellum, spinal cord, and other motor output nuclei were never damaged. It was found that some structures were rated as more severely damaged when evaluated at shorter survival times. Severity of neural damage was related to high levels of EEG delta power recorded 24 hr after exposure; power during the acute seizure or 24 hr body weight loss did not predict lesion severity. Sections between AP -0.8 to -4.8 contain cortical and subcortical structures that can be readily and reproducibly evaluated for brain damage.

Minimal increase in gut-mucosal interleukin-6 during laparoscopy

BACKGROUND

The gut clearly plays a significant role in postoperative recovery. Other investigators have shown an increase in gut-mucosal cytokines in septicemia and burn models. We tested the effects of laparotomy and laparoscopy on gut-mucosal IL-6 production.

METHODS

A/J mice were randomized to three groups: control, laparotomy plus bowel manipulation (OBM), and laparoscopy plus bowel manipulation (LBM). Serum and gut-mucosal samples obtained at 4 and 8 h after surgery were analyzed for IL-6.

RESULTS

We found that OBM is associated with increased serum and gut-mucosal IL-6 at both 4 and 8 h after surgery. In contrast, LBM showed a blunted response in serum IL-6 and no change in gut-mucosal IL-6 at both time intervals.

CONCLUSIONS

We conclude that laparoscopy minimizes trauma to the peritoneal environment, thereby decreasing the gut's inflammatory response to operation. This differential response of the gut may partially explain the preservation of gut function following laparoscopy.

Tumor response, mucosal reactions and late effects after conventional and hyperfractionated radiotherapy

BACKGROUND

Relationships between normal tissue reactions and tumor response to radiotherapy have generally been investigated in retrospective studies, with the attendant difficulties such as different times of treatment and lack of standard scales for scoring of normal tissue reactions. This study analyses the correlation between normal tissue reactions and tumor response in a randomized trial of hyperfractionation versus conventional radiotherapy.

MATERIALS AND METHODS

EORTC trial 22791, which accrued 325 T2-3, N0-1 and M0 oropharynx squamous cell carcinomas, compared conventional radiotherapy (70 Gy in 7 weeks) to a hyperfractionated regime (two daily irradiations of 1.15 Gy up to 80.5 Gy in 7 weeks). Acute and late toxicities were assessed according to the RTOG/EORTC scales. The variables were tumor regression at treatment completion, tumor control for unlimited follow-up, severity of acute mucosal reactions (grade of the peak reaction, time to onset of grade 2 mucositis, or duration of acute reactions of grade 3) and severity of late effects in normal tissues (late ulceration, cervical edema secondary to lymphatic drainage damage, late muscular fibrosis, or late mucosal necrosis as consequential damage). Kendall's rank correlation was used to assess the levels of significance of the correlation. The 95% confidence interval (95% CI) was calculated for each correlation tau-b coefficient.

RESULTS

Irradiation doses and overall treatment times were consistent between the treatment arms. The time to onset of patchy mucosal reactions was inversely correlated to tumor regression at treatment completion in the hyperfractionated arm (arm 2) but not in the conventional fractionation arm (arm 1). The other significant correlations were restricted to the following pairs of end-points and patient subgroups: acute mucositis of grade 3 versus tumor regression at the end of treatment in arm 2 for T2 tumors, late ulceration versus tumor control in arm 2 and acute mucosal reactions versus late effects in normal tissues in arm 2 for T3 tumors. By and large, the 95% CIs for Kendall's tau-b included zero and did not include 0.5, an indication that the comparison had sufficient power to detect a difference, if indeed one existed.

CONCLUSIONS

These results do not represent clinical evidence strong enough to demonstrate that individual differences in sensitivity influence the response of tumors to radiation.

GM1 monosialoganglioside pretreatment protects against soman-induced seizure-related brain damage

The effects of GM1 monosialoganglioside pretreatment on brain damage resulting from soman-induced seizure activity were examined in this study. Male Sprague-Dawley rats were infused with GM1 via an osmotic minipump connected through a permanent cannula implanted intracerebroventricularly and challenged with soman (83 micrograms/kg, i.e., 1.25 x LD50) 4 d after initiation of GM1 infusion. Electrocorticographic recordings were monitored via indwelling cortical electrodes. Twenty-seven hours after soman administration, anesthetized rats were euthanized via transcardial perfusion with buffered paraformaldehyde. Brains were processed for hematoxylin and eosin (H&E), cresyl violet (CV), and acetylcholinesterase (AChE) histochemistry, and glial fibrillary acidic protein (GFAP) and microtubule-associated protein 2 (MAP2) immunohistochemistry. All soman-challenged rats not infused with GM1 (n = 14) developed status epilepticus (SE).