Crystallization and preliminary X-ray diffraction analysis of protein L-isoaspartyl O-methyltransferase from wheat germ

Wheat-germ protein L-isoaspartyl O-methyltransferase (WPIMT) can initiate the conversion of L-isoaspartyl residues in a protein or peptide, which accumulate during the aging process in wheat-germ seeds, to normal L-aspartyl groups. The recombinant protein of WPIMT was overexpressed in Escherichia coli and purified to homogeneity. The protein was crystallized in the presence of S-adenosine-L-homocysteine using 2-methyl-2,4-pentanediol. Preliminary X-ray analysis indicated a tetragonal space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 77.3, c = 152.9 A for cryofrozen crystals at 90 K. The crystals diffracted to 3.3 A and contain two molecules per asymmetric unit.

Choice of insufflating gas influences on wound metastasis

BACKGROUND

Laparoscopic cancer surgery is limited by concerns about port-site metastasis. No study has definitively addressed the behavior and growth of tumor cells after the use of specific laparoscopic gases.

METHODS

In athymic rats, 10,000 colon cancer cells were injected intraperitoneally. The rats received either no pneumoperitoneum (pneumo) or pneumo (8 mmHg, 10 min) with carbon dioxide (CO(2)), nitrous oxide (N(2)O), or air. Two full-thickness incisions were made and closed in the upper abdomen of each animal. After 4 weeks, implants were identified grossly at necropsy, and invasiveness was scored according to penetration through the layers of the abdominal wall.

RESULTS

Rats receiving pneumo had more frequent implants (p < 0.01) with deeper penetration (p < 0.001) than rats not receiving pneumo. Implants were more common after air pneumo than after CO(2) (p < 0.05) or N(2)O (p = 0.07) pneumo, and were less penetrating after CO(2) pneumo than after air (p < 0.001) or N(2)O (p < 0.05) pneumo.

CONCLUSIONS

Carbon dioxide gas may limit the viability and invasiveness of free intraperitoneal tumor cells, as compared with air or N(2)O.

"Preclinical" AD revisited: neuropathology of cognitively normal older adults

OBJECTIVE

To classify neuropathologic alterations in the brains of nondemented older adults using current sets of criteria for AD.

BACKGROUND

AD neuropathologic alterations are found in the brains of some nondemented elderly subjects and suggest the possibility of presymptomatic AD. Three sets of guidelines have been developed to classify AD using senile plaques, neuritic plaques, and neurofibrillary tangles (NFT).

METHODS

Neuropathologic changes in 59 older adults followed longitudinally with a standard battery of mental status measures were investigated using Khachaturian, Consortium to Establish a Registry for Alzheimer's Disease (CERAD), and National Institute on Aging-Reagan Institute (NIA-RI) guidelines. AD neuropathologic markers were evaluated in neocortical and allocortical regions. Cases were categorized as neuropathologically "normal" or "AD-like" and compared for possible mental status differences.

RESULTS

Between 11 and 49% of cases met one or more of the three classifications of AD. With adjustments for multiple comparisons, only NFT in hippocampal CA1 region were associated with autopsy age, suggesting that this may represent a pathologic process associated with normal brain aging. Using the NIA-RI guidelines, subjects in the AD-like group performed less well on the immediate paragraph recall and word-list delayed recall than their counterparts who did not meet these guidelines.

CONCLUSIONS

These data indicate that the prevalence of "preclinical" AD in our population is relatively low based on the NIA-RI classification. Although many subjects had AD-like changes based on CERAD and Khachaturian guidelines, they exhibited no differences in mental performance, suggesting that the aging brain may be able to withstand such structural changes without meaningful impact on mental functioning.

Locoregional recurrence patterns after mastectomy and doxorubicin-based chemotherapy: implications for postoperative irradiation

PURPOSE

The objective of this study was to determine locoregional recurrence (LRR) patterns after mastectomy and doxorubicin-based chemotherapy to define subgroups of patients who might benefit from adjuvant irradiation.

PATIENTS AND METHODS

A total of 1,031 patients were treated with mastectomy and doxorubicin-based chemotherapy without irradiation on five prospective trials. Median follow-up time was 116 months. Rates of isolated and total LRR (+/- distant metastasis) were calculated by Kaplan-Meier analysis.

RESULTS

The 10-year actuarial rates of isolated LRR were 4%, 10%, 21%, and 22% for patients with zero, one to three, four to nine, or >/= 10 involved nodes, respectively (P <.0001). Chest wall (68%) and supraclavicular nodes (41%) were the most common sites of LRR. T stage (P <.001), tumor size (P <.001), and >/= 2-mm extranodal extension (P <.001) were also predictive of LRR. Separate analysis was performed for patients with T1 or T2 primary disease and one to three involved nodes (n = 404). Those with fewer than 10 nodes examined were at increased risk of LRR compared with those with >/= 10 nodes examined (24% v 11%; P =.02). Patients with tumor size greater than 4.0 cm or extranodal extension >/= 2 mm experienced rates of isolated LRR in excess of 20%. Each of these factors continued to significantly predict for LRR in multivariate analysis by Cox logistic regression.

CONCLUSION

Patients with tumors >/= 4 cm or at least four involved nodes experience LRR rates in excess of 20% and should be offered adjuvant irradiation. Additionally, patients with one to three involved nodes and large tumors, extranodal extension >/= 2 mm, or inadequate axillary dissections experience high rates of LRR and may benefit from postmastectomy irradiation.

Plasmodium falciparum rab6 GTPase: expression, purification, crystallization and preliminary crystallographic studies

The Plasmodium falciparum rab6 gene encodes a 208 amino-acid polypeptide. Two recombinant versions of P. falciparum Rab6 protein were expressed in Escherichia coli: the full-length protein and a truncated form containing residues 1-175. Both forms were purified from the soluble fraction of bacterial extract and were purified by ion-exchange chromatography and size-exclusion chromatography. Purified proteins were crystallized at pH 6.5 using the hanging-drop vapor-diffusion technique at room temperature. The full-length protein diffracted to 2.4 A and belongs to the tetragonal space group P4(3)2(1)2 or P4(1)2(1)2, with unit-cell parameters a = b = 80. 6, c = 90.4 A. The crystals of the truncated protein were isomorphous with those of the full-length construct and diffracted X-rays to 2.2 A resolution.

Electrospray ionization mass spectrometry of stable nitroxide free radicals and two isoindoline nitroxide dimers

Electrospray ionization (ESI) mass spectra were recorded for a range of substituted isoindoline nitroxides, two isoindoline nitroxide dimers and two piperidinyl nitroxides. In all cases the dominant molecular species arise from oxidation rather than protonation, an unusual process in ESI. Fragment ion spectroscopy was used to establish fragmentation mechanisms for the nitroxides under ESI conditions.

Serum folate and the severity of atrophy of the neocortex in Alzheimer disease: findings from the Nun study

BACKGROUND

Previous studies suggested that low concentrations of folate in the blood are related to poor cognitive function, dementia, and Alzheimer disease-related neurodegeneration of the brain.

OBJECTIVE

Our aim was to determine whether serum folate is inversely associated with the severity of atrophy of the neocortex.

DESIGN

Nutrients, lipoproteins, and nutritional markers were measured in the blood of 30 participants in the Nun Study from one convent who later died when they were 78-101 y old (mean: 91 y). At autopsy, several neuropathologic indicators of Alzheimer disease were determined, including the degree of atrophy of 3 lobes of the neocortex (frontal, temporal, and parietal) and the number of neocortical Alzheimer disease lesions (ie, senile plaques and neurofibrillary tangles) as assessed by a neuropathologist.

RESULTS

The correlation between serum folate and the severity of atrophy of the neocortex was -0.40 (P = 0.03). Among a subset of 15 participants with significant numbers of Alzheimer disease lesions in the neocortex, the correlation between folate and atrophy was -0.80 (P = 0.0006). Atrophy may be specific to low folate because none of the 18 other nutrients, lipoproteins, or nutritional markers measured in the blood had significant negative correlations with atrophy.

CONCLUSIONS

Among elderly Catholic sisters who lived in one convent, ate from the same kitchen, and were highly comparable for a wide range of environmental and lifestyle factors, low serum folate was strongly associated with atrophy of the cerebral cortex. Definitive evidence for this relation and its temporal sequence awaits the findings of other studies.

Neuroprotective effects of HU-211 on brain damage resulting from soman-induced seizures

Neuroprotective effects of HU-211 (dexanabinol), a synthetic nonpsychotropic analog of tetrahydrocannabinol, on brain damage resulting from soman-induced seizures were examined in male Sprague-Dawley rats challenged with 1.6 LD50 soman. At 5 or 40 min after onset of seizures, the rats were given an intraperitoneal injection of 25 mg/kg HU-211. All rats that received soman showed electrocorticographic (ECoG) evidence of sustained seizures and status epilepticus for 4-6 hr. HU-211 had no effect on either the strength or duration of seizure activity. Administration of HU-211 at 5 min after seizure onset reduced median lesion volume 86% (as assessed by microtubule-associated protein 2 (MAP2)-negative staining), and when administered 40 min post-onset, the reduction in necrosis was 81.5% despite the presence of continuous seizures for 4-5 hr. These observations were corroborated by hemotoxylin and eosin (H&E) histopathological assessment that showed a significant reduction in piriform cortical neuronal damage in HU-211-treated animals. It is concluded that HU-211 provides considerable neuroprotection against brain damage produced by soman-induced seizures.

Heartburn is more likely to recur after Toupet fundoplication than Nissen fundoplication

Toupet (270 degrees) fundoplication is commonly recommended for patients with gastroesophageal reflux (GER) and esophageal dysmotility. However, Toupet fundoplication may be less effective at protecting against reflux than Nissen (360 degrees) fundoplication. We therefore compared the effectiveness and durability of both types of fundoplication as a function of preoperative esophageal motility. From January 1992 through January 1998, 669 patients with GER underwent laparoscopic fundoplication (78 Toupet, 591 Nissen). Patients scored heartburn, regurgitation, and dysphagia preoperatively, and at 6 weeks and 1 year postoperatively, using a 0 ("none") to 3 ("severe") scale. We compared symptom scores (Wilcoxon rank sum test) and redo fundoplication rates (Fisher exact test) in Toupet and Nissen patients. We also performed subgroup analyses on 81 patients with impaired esophageal motility (mean peristaltic amplitude, <30 mm Hg or peristalsis <70% of wet swallows) and 588 patients with normal esophageal motility. Toupet and Nissen patients reported similar preoperative heartburn, regurgitation, and dysphagia. At 6 weeks after operation, heartburn and regurgitation were similarly improved in both groups, but dysphagia was more prevalent among Nissen patients. After 1 year, heartburn and regurgitation were re-emerging in Toupet patients, and dysphagia was again similar between groups. Patients with impaired motility who have Nissen fundoplication are no more likely to suffer persistent dysphagia than their counterparts who have Toupet fundoplication. In addition, patients with normal motility are more likely to develop symptom recurrence after Toupet fundoplication than Nissen fundoplication, with no distinction in dysphagia rates. We conclude that since Toupet patients suffer more heartburn recurrence than Nissen patients, with similar dysphagia, selective use of Toupet fundoplication requires further study.

Chronic ureteral obstruction in the rat suppresses renal tubular Bcl-2 and stimulates apoptosis

Unilateral ureteral obstruction (UUO) results in widespread tubular apoptosis in obstructed kidneys of both adults and neonates. The oncoprotein bcl-2 inhibits many forms of apoptosis, whereas the related protein bax promotes apoptosis. To evaluate the interaction of bcl-2, bax, and apoptosis in the renal response to UUO, adult and neonatal rats were subjected to UUO or sham operation, and kidneys were harvested 14 days later. Apoptotic cells were identified by the Tunel technique, and the distribution of bcl-2 and bax was determined by immunochemistry. In both adults and neonates, tubular and interstitial apoptosis was present in the obstructed kidney, but not in intact kidneys. In both adults and neonates, there was diffuse tubular bcl-2 and bax staining of sham-operated and intact kidneys. While bcl-2 was increased in scattered nonapoptotic tubules of the obstructed kidney, there was minimal staining of dilated apoptotic tubules. These results are consistent with the premise that bcl-2 normally suppresses renal tubular apoptosis. The distribution of bax staining in tubules of the obstructed kidney overlapped that of bcl-2. We conclude that chronic UUO inhibits bcl-2 expression in selected tubules of the obstructed kidney which contributes to activation of apoptosis and progressive renal damage in either neonatal or adult kidneys. Dysregulation of apoptosis may be a response to renal injury similar to that underlying the development of cystic kidney disease or renal dysplasia.

White matter volumes and periventricular white matter hyperintensities in aging and dementia

OBJECTIVE

To determine the relationship between MRI periventricular white matter hyperintensities, cerebral white matter volumes, neuropathologic findings, and cognitive status in aged individuals.

BACKGROUND

The significance of periventricular white matter hyperintensities seen on MR images in aged individuals remains controversial. The Nun Study is a longitudinal cohort aging study in which all 678 initially enrolled participants agreed to autopsy neuropathologic examination.

METHODS

We used MRI to measure white matter volumes of the cerebral hemispheres in 52 formaldehyde-fixed brains for correlation with white matter and neocortical pathology, postmortem MRI observations, and cognitive measures.

RESULTS

Reduced white matter volume is associated with dementia, but periventricular white matter hyperintensities were not related to white matter volume, stroke, or dementia.

CONCLUSIONS

Our results do not support the hypothesis that periventricular hyperintensities seen on MR images have deleterious consequences in these aged individuals.

Periventricular white matter hyperintensities on MRI: correlation with neuropathologic findings

Periventricular white matter hyperintensities on postmortem magnetic resonance imaging (MRI) and myelin-stained frontal and parietal histologic sections were evaluated independently in 12 cases. There was a strong relationship between the extent of white matter hyperintensities on MRI and the extent of gross and microscopic changes seen in the white matter of myelin-stained sections, particularly in the frontal lobe. In this material, the extent of myelin rarefaction correlated with a 0- to 8-point white matter hyperintensity scale rating on MRI in the same brains.

Anticonvulsant treatment of nerve agent seizures: anticholinergics versus diazepam in soman-intoxicated guinea pigs

A total of eight anticholinergic drugs (aprophen, atropine, azaprophen, benactyzine, biperiden, procyclidine, scopolamine, trihexyphenidyl) were tested in parallel with diazepam for the ability to terminate seizure activity induced by the nerve agent soman. Guinea pigs, implanted with electrodes to record cortical electroencephalographic (EEG) activity, were pretreated with pyridostigmine Br (0.026 mg/kg, i.m.) and 30 min later challenged with 2 x LD50 soman (56 microg/kg, s.c.) followed 1 min later by treatment with atropine SO4 (2 mg/kg, i.m.) and pralidoxime chloride (2-PAM Cl; 25 mg/kg, i.m.). All guinea pigs developed sustained seizure activity following this treatment. Dose-effect curves were determined for the ability of each drug to terminate seizure activity when anticonvulsant treatment was given either 5 or 40 min after seizure onset. Body weight gain and recovery of behavioral performance of a previously trained one-way avoidance task were measured after exposure. With the exception of atropine, all anticholinergic drugs were effective at lower doses than diazepam in terminating seizures when given 5 min after seizure onset; benactyzine, procyclidine and aprophen terminated seizures most rapidly while scopolamine, trihexyphenidyl, biperiden, and diazepam were significantly slower. When given 40 min after seizure onset, diazepam was the most potent compound tested, followed by scopolamine, benactyzine and biperiden; atropine was not effective when tested 40 min after seizure onset. For diazepam, the time to terminate the seizure was the same whether it was given at the 5- or 40-min delay. In contrast, most anticholinergics were significantly slower in terminating seizure activity when

Structure-activity studies of cerulenin analogues as protein palmitoylation inhibitors

Activation of ras oncogenes occurs in a high percentage of tumors, making the enzymes involved in the posttranslational processing of their encoded proteins (p21s) attractive targets for the development of new drugs. Although most effort has focused on farnesyl transferase, which catalyzes the first processing step, attachment of palmitate to p21 is required for optimal transformation by H-ras and N-ras. We have demonstrated that the natural product cerulenin ([2R,3S]-2,3-epoxy-4-oxo-7,10-trans,trans-dodecadienamide) inhibits the palmitoylation of H-ras- and N-ras-encoded p21s in parallel with inhibition of cell proliferation. More than 30 analogues of cerulenin, both aromatic and aliphatic, with various chain lengths and amide substitutions, have been synthesized for use in SAR studies. Studies on the inhibition of T24 cell proliferation indicate that the alpha-keto-epoxy moiety is critical for cytotoxicity, while alkyl chain length had only modest effects on potency. Several compounds inhibited the incorporation of [(3)H]palmitate into p21 in intact T24 cells, with the unsubstituted carboxamides being more active than N,N-dimethyl compounds. In contrast to the effects on palmitoylation, the only compounds which inhibited fatty acid synthase contained alkyl side chains of 12 carbons or fewer. Regression analyses indicated that inhibition of palmitoylation is more closely related to inhibition of proliferation than is inhibition of fatty acid synthase. Further characterization of the molecular pharmacology of these and analogous compounds may define a new class of drugs with antitumor activity.

Altered brain activation in cognitively intact individuals at high risk for Alzheimer's disease

OBJECTIVE

To determine whether brain function is altered in cognitively normal individuals at high risk for AD several years before the typical age at onset for this illness.

BACKGROUND

Neuropathologic alterations in AD precede cognitive impairment by several years. It is unknown whether functional alterations in neural circuitry accompany these neuropathologic changes, and if so, whether they may be detectable before onset of symptoms.

METHODS

We used functional MRI to compare cortical activation between two groups of cognitively normal women differing only in their risk for developing AD. Visual naming and letter fluency tasks were used to activate brain areas subserving object and face recognition, previously described sites of hypometabolism and neuropathologic alteration in AD. The risk groups differed in family history of AD and apolipoprotein E allele status, but were matched in age, education, and measures of cognitive performance. Average age of the study participants was 52 years.

RESULTS

The regional patterns of brain activation were similar between groups. However, the high risk group showed areas of significantly reduced activation in the mid- and posterior inferotemporal regions bilaterally during both tasks despite identical naming and letter fluency performance.

CONCLUSIONS

Cognitively normal individuals at high risk for AD demonstrate decreased brain activation in key areas engaged during naming and fluency tasks. Decreased activation in the high risk group may be a consequence of the presence of subclinical neuropathology in the inferotemporal region or in the inputs to that region. If so, these findings provide evidence of a window of opportunity for disease-modifying treatment before the onset of symptomatic AD.

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).

A long-term study of hydroxychloroquine withdrawal on exacerbations in systemic lupus erythematosus. The Canadian Hydroxychloroquine Study Group

The ability of antimalarials to moderate severe disease activity in systemic lupus erythematosus (SLE) is plausible but undemonstrated. We evaluated the long-term effectiveness of maintaining treatment with hydroxychloroquine sulphate (HCQ) to prevent major flares in quiescent SLE. Forty-seven patients with quiescent SLE who had been randomized to take HCQ (n = 25) or placebo (n = 22) as part of a 24-week withdrawal trial were evaluated for an additional 3 years. The primary outcome was time to a major flare of SLE which resulted in either the institution of or an increase in the current dosage of prednisone of 10 mg/day or more, or institution of therapy with immunosuppressive agents. Secondary outcomes included the specific subtype of these major flares (glomerulonephritis, vasculitis or other) and hospitalization for an exacerbation of SLE. An intent-to-treat analysis was conducted. Over the 42 months of study, 11 of 22 (50%) patients randomized initially to placebo, and seven of 25 (28%) patients randomized to continue treatment experienced a major flare. The relative risk of major flare for those randomized to continue HCQ compared with controls was 0.43 (95% CI: 0.17, 1.12). The relative risks for subtypes of flares were 0.26 (95% CI: 0.03, 2.54) for nephritis, 0.51 (95% CI: 0.09, 3.08) for vasculitis and 0.65 (95% CI: 0.17, 2.41) for flares characterized by other symptoms. The relative risk of hospitalization for major flare for patients randomized to continue hydroxychloroquine was 0.58 (95% CI: 0.13, 2.60). While the results are not statistically significant, they are compatible with the clinical belief that HCQ has a long-term protective effect against major disease flares in SLE and suggest that on average, HCQ use reduces major flares by 57% (95% CI: 83% reduction to 12% increase).

Design, synthesis, and evaluation of the multidrug resistance-reversing activity of D-glucose mimetics of hapalosin

When five substituents of hapalosin were placed on D-glucose, molecular modeling revealed that the substituents on mimetics 2 and 3 occupy similar spatial positions as the corresponding substituents on hapalosin. Mimetic 3 and all the glucopyranoside intermediates generated in its synthesis were assessed for their ability to reverse multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) or the multidrug resistance-associated protein (MRP). None of the sugar compounds were as effective as hapalosin in inhibiting P-gp in cytotoxicity and drug accumulation assays using MCF-7/ADR cells. By contrast, four D-glucose compounds exhibited similar efficacy as hapalosin in antagonizing MRP in cytotoxicity assays with HL-60/ADR cells.

Pharmacokinetics, pharmacodynamics, and safety of metrifonate in patients with Alzheimer's disease

Metrifonate is converted nonenzymatically to 2.2, dimethyl dichlorovinyl phosphate (DDVP), an inhibitor of acetylcholinesterase (AChE). This 21-day, randomized, double-blind, placebo-controlled trial of metrifonate in patients with Alzheimer's disease (n = 27) evaluated four doses, each administered orally once daily. All patients received a loading dose (LD) for 6 days followed by a maintenance dose (MD) for 15 days. The treatment groups were: panel 1, LD = 1.5 mg/kg (75-135 mg), MD = 0.25 mg/kg (12.5-25 mg); panel 2, LD = 2.5 mg/kg (125-225 mg), MD = 0.40 mg/kg (20-35 mg); panel 3, LD = 4.0 mg/kg (200-335 mg), MD = 0.65 mg/kg (30-60 mg); and panel 4, LD = 4.0 mg/kg (200-335 mg), MD = 1.0 mg/kg (50-90 mg). All metrifonate doses were well tolerated. Most adverse events were mild to moderate in intensity, gastrointestinal in nature, and transient. Mean area under the concentration-time curve (AUC) and maximum concentration (Cmax) for both metrifonate and DDVP increased in relation to dose. Metrifonate and DDVP had similar, largely dose-independent mean values for time to Cmax (tmax) and half-life (t1/2). There was little or no accumulation of either metrifonate or DDVP with long-term administration. After 21 days of treatment, mean percent erythrocyte AChE inhibition was 14%, 35%, 66%, 77%, and 82% for placebo and panels 1 through 4, respectively. Cognitive improvement was observed with the two highest metrifonate doses. These results reflect favorable safety and pharmacokinetic profiles for the use of metrifonate in the treatment of Alzheimer's disease.

Preoperative perfusion of bypassed ileum does not improve postoperative function

This study evaluated whether twice daily isotonic perfusion of the bypassed ileum for six weeks would enhance its motor activity and its absorption of fluids, electrolytes, and vitamin B12. The study also determined if patients undergoing perfusion had improved bowel function and decreased hospital stay after ileostomy closure. Following proctocolectomy, ileal pouch-anal canal anastomosis, and diverting loop ileostomy, six patients self-infused an isotonic solution (sucrose and sodium chloride) into the bypassed ileum twice daily, while seven patients did not (controls). Two months following proctocolectomy, and just prior to ileostomy closure, a manometric catheter assembly was placed into the unused distal ileum via the stoma and the distal ileum perfused with an isotonic sodium chloride solution for 3 hr during fasting and 3 hr after a meal. Absorption was measured, single and clustered pressure waves were identified, and a motility index was calculated. Water absorption, motility index, and cluster parameters did not improve in perfused patients compared to controls during fasting or after a meal, nor did perfused patients have improved vitamin B12 absorption. The perfused patients also did no better clinically following ileostomy takedown; the onset of bowel movements, their frequency, time to tolerate a diet, and hospital stay were similar to controls. We conclude that six weeks of twice daily isotonic perfusion did not improve motor activity or water, electrolyte, and vitamin B12 absorption in the bypassed distal ileum after proctocolectomy, ileal pouch-anal canal anastomosis, and loop ileostomy. The perfusion also did not improve bowel function after ileostomy takedown.

Brain creatine kinase with aging in F-344 rats: analysis by saturation transfer magnetic resonance spectroscopy

We measured in vivo forward flux of the creatine kinase reaction in rat forebrain in young (Y: 6 month, n = 13), mid-aged (M: 12 month, n = 7) and aged (O: 27 month, n = 10) animals using 31P magnetic resonance saturation transfer. Forward flux was reduced in the aged rats (Y: 0.42 +/- 0.08; M: 0.41 +/- 0.10; O: 0.31 +/- 0.03 s(-1) +/- SD; p = 0.008 O vs. Y). In vitro studies in a subset of the same rats showed a parallel decline in CK activity (Y: 2.16 +/- 0.40; M: 2.17 +/- 0.25; O: 1.56 +/- 0.06 IU +/- S.D.; p = 0.002 O vs. Y). The in vivo spectroscopic and in vitro biochemical measures were significantly correlated. Reduced creatine kinase activity could account for the observed decreased forward flux in aging brain. Intracellular pH, phosphocreatine/inorganic phosphate ratio, and phospocreatine/gamma-adenosine triphosphate ratio did not differ between groups. Forward flux may represent a better measure of brain energy function than relative phosphocreatine or adenosine triphosphate levels observable in vivo.

Intraoperative events common to videoscopic preperitoneal mesh inguinal herniorrhaphy

BACKGROUND

Videoscopic preperitoneal mesh (VPM) inguinal herniorrhaphy avoids the entry into the abdominal cavity, which is necessary with other videoscopic techniques. Despite this advantage, surgeons have been slow to adopt this technique. We reviewed our experience with VPM inguinal herniorrhaphy, specifically investigating the technical aspects of this approach.

METHODS

Data were collected prospectively. Operative notes were reviewed retrospectively detailing intraoperative events not "typical" with the VPM technique.

RESULTS

One hundred consecutive patients undergoing VPM repair of 127 hernias were studied. The repair was completed in all but 2 patients. Mean operating time was 120 minutes (60 to 146). In 36 repairs there were 59 intraoperative "events" requiring specific maneuvers to correct. Events identified were the need for transection of the hernia sac, creation and repair of a peritoneal tear, and need to divide the inferior epigastric vessels. No complications related to these events occurred. When events occurred, operative times were significantly longer (146+/-45 versus 83+/-23 minutes; P <0.05).

CONCLUSION

Intraoperative events are common with VPM herniorrhaphy. These events significantly prolong operating time. A surgeon's lack of familiarity with such events and how to deal with them may in part explain the reluctance to widely apply the VPM technique.