Differential effects of endomorphin-1 and -2 on amphetamine sensitization: neurochemical and behavioral aspects

Mu-opioid receptors are known to modulate mesolimbic dopaminergic activity in the ventral tegmental area via disinhibition of GABA-containing neurons. Recently, two novel tetrapeptides, endomorphin-1 and endomorphin-2, were identified in the mammalian brain and reported to have high binding affinities toward mu-opioid receptors. To determine if endomorphins would modulate the development of amphetamine sensitization, we administered endomorphins locally into the rat brain followed by behavioral and neurochemical examinations. The results indicate that rats pretreated with endomorphin-1 or -2 (5 microg per side for 7 days) in the ventral tegmental area developed locomotor sensitization to the challenge injection of amphetamine (1 mg/kg). On the other hand, when endomorphins were given in the lateral ventricle (20 microg for 5 days) of amphetamine-sensitized rats (5 mg/kg x 14 days) during the withdrawal period (w5-w9), neither peptide had a modulatory effect on locomotor sensitization. Biochemical analyses revealed that treatment with endomorphins in the ventral tegmental area significantly increased the levels of glutamate in the medial prefrontal cortex and ventral and dorsal striatum to levels comparable to those observed in the amphetamine-sensitized rats. In the same animals, endomorphins also caused decreases in the levels of serotonin and its metabolite, 5-hydroxyindoleacetic acid, in the medial prefrontal cortex. Interestingly, although there was no behavioral significance, endomorphin-1 treatment in the lateral ventricle of control and amphetamine-sensitized rats during withdrawal resulted in decreases of GABA, aspartate, dopamine, and its metabolite 3,4-dihydroxyphenylacetic acid in the ventral striatum. We conclude that endomorphins, by stimulating the mu-opioid receptors in the ventral tegmental area, could sensitize the behavioral response to amphetamine. The results also demonstrate that there are differential responses between endomorphin-1 and -2 on behavioral amphetamine sensitization and the underlying neurochemical substrates.

Effects of luteolin on arylamine N-acetyltransferase activity in human liver tumour cells

The human liver tumour cell line (J5) was selected in order to evaluate whether or not luteolin affected arylamine N-acetyltransferase (NAT) activity. Using high performance liquid chromatography, the NAT activity for acetylation of arylamine substrates (2-aminofluorene and p-aminobenzoic acid) was determined. The cytosolic NAT activity in human liver tumour cells was 2.74+/-0.26 and 1.68+/-0.20 nmol/min/mg of protein for 2-aminofluorene and p-aminobenzoic acid, respectively. Luteolin displayed a dose-dependent inhibition to cytosolic NAT activity and intact human liver tumour cells. Time-course experiments showed that NAT activity measured from intact human liver tumour cells was inhibited by luteolin for up to 24 h. Using standard steady-state kinetic analysis, it was shown that luteolin was a possible noncompetitive inhibitor to NAT activity in cytosols. This report is the first to show how luteolin affects NAT activity in human liver tumour cells.

Therapeutic effect of gypenoside on chronic liver injury and fibrosis induced by CCl4 in rats

Gypenoside is a saponins extract derived from the Gynostemma pentaphyllum. The purpose of this study was to evaluate the hepatoprotective and antifibrotic potential of Gypenoside on chronic liver injury induced by CCl4 for 8 wks. The results indicated that the increase of SGOT, SGPT activities in CCl4 liver injury were significantly reduced by treatment with Gypenoside. It also elevated the A/G ratio. For the study of anti-fibrotic potential, Gypenoside reduced the collagen content by 33%. These phenomena were confirmed by pathologic observation; thinner bands of liver collagen were found. The results suggest that Gypenoside has hepatoprotective and anti-fibrotic activities.

Risk of immediate effects from F(ab)2 bivalent antivenin in Taiwan

OBJECTIVE

To evaluate the incidence of immediate adverse effects from equine fragment antigen binding F(ab)2 bivalent antivenin produced by the National Institute of Preventive Medicine (NIPM) in Taiwan.

METHODS

A retrospective chart review of patients presenting to a 600-bed general hospital over a 3-year period with snakebite who were treated with NIPM antivenin.

RESULTS

A total of 130 snakebite victims presented to the emergency department over the study period, and 159 vials of antivenin were given. One hundred two patients (78.5%; 95% CI: 70, 85) received only hemorrhagic bivalent antivenin, 2 (1.5%; 95% CI: 0, 5) received only neurotoxic bivalent antivenin, and the remaining 26 (20.0%; 95% CI: 13, 28) received both kinds of bivalent antivenin. Three received a second vial of hemorrhagic antivenin because of progression of symptoms. Forty-two patients (32.3%; 95% CI: 24, 41) had positive skin tests, but following pretreatment with diphenhydramine and hydrocortisone, only 1 patient developed a skin rash thought to be related to antivenin. No patient developed an anaphylactic reaction.

CONCLUSIONS

The use of NIPM F(ab)2 antivenin in snakebite victims in Taiwan has a very low risk of acute adverse reactions.

Protective role of Bcl2 in metabolic oxidative stress-induced cell death

Previous studies have shown that overexpression of Bcl2 protects cells from glucose deprivation-induced cell death in multidrug-resistant human breast carcinoma, MCF-7/ADR cells. In this study, we further investigated the protective role of Bcl2 in glucose deprivation-induced cytotoxicity. Although Bcl2 did not prevent a 3.2-fold increase in the level of hydroperoxide during glucose deprivation, it led to a compartmentalization of hydroperoxide molecules in the mitochondria. It also inhibited glucose deprivation-induced cytochrome c release from the mitochondria. It is possible that overexpression of Bcl2 prevents glucose deprivation-induced ceramide generation, probably by preventing the leakage of hydroperoxide from the mitochondria. We also observed that glucose deprivation induced a sixfold increase in oxidized glutathione content, as well as in thiol precursor content. Overexpression of Bcl2 suppressed an increase in oxidized glutathione content and thiol precursor content. Our results indicate that Bcl2 protects cells from metabolic oxidative stress-induced damage by inhibiting the leakage of hydroperoxide from the mitochondria and subsequently preventing ceramide generation. Preventing ceramide generation inhibits the signal transduction pathway and results in the suppression of cytochrome c release from the mitochondria.

Thymic hyperplasia in a patient with Graves' disease

Hyperplastic changes of the thymus may be found in patients with Graves' disease. However, this rarely presents as an anterior mediastinal mass, particularly among adults. In this report, we describe a 32-year old woman with Graves' disease and hyperthyroidism. During medical evaluation and treatment for her hyperthyroidism, a large anterior mediastinal mass was incidentally discovered. A cytological study of the lesion via computed tomogram-guided fine needle biopsy could not make a definitive diagnosis and suggested the possibility of a thymoma, which led to a surgical exploration. However, the final pathological diagnosis of the surgically removed tissue was thymic hyperplasia. The relationship between Graves' disease and thymic changes is discussed.

[Effects of 8 years community intervention on risk factors of cardiovascular diseases in Fangshan Beijing]

OBJECTIVE

To study the changes of risk factors of cardiovascular disease in the rural community population after intervention.

METHODS

The Beijing Fangshan cardiovascular prevention program was a community-based comprehensive intervention study which was launched from 1991 and ended in 2000 in five communities including three as intervention communities (IC) and two as control communities (CC) in Fangshan, Beijing suburb. The intervention measures were focused on health education and hypertension control. The changes of risk factors of cardiovascular disease in IC and CC were analyzed using random sample in the year 1991, 1995 and 1999, respectively. The risk factors include systolic and diastolic blood pressure (SBP and DBP), body mass index(BMI), serum total cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol(HDL), smoking, and drinking.

RESULTS

From the year 1991 to 1999, the risk factors of cardiovascular disease such as SBP, DBP, smoking rate and drinking rate were reduced in the population of IC. For male in IC, the decline of SBP, DBP, smoking rate, and drinking rate were 1.6 mmHg, 1.1 mmHg, 14.5% (P < 0.01) and 3.7%, respectively. For female of IC, SBP and DBP declined 4.8 mmHg (P < 0.01) and 3.2 mmHg (P < 0.01), respectively. SBP, DBP and smoking rate in the population of CC had a little reduction while BMI, TC and TG increased in both IC and CC. During the period of 1991 to 1999, most cardiovascular risk factors in the population of IC had net reduction compared to that of CC.

CONCLUSIONS

Except for BMI and lipids, rural community intervention, as focused on health education and hypertension control, has resulted in the reduction of most risk factors of cardiovascular disease.

The time-course change of nitrogenous excretion in the Kuruma shrimp Penaeus japonicus following nitrite exposure

Penaeus japonicus (12.83 +/- 1.24 g) which were exposed individually to 0.002 (control), 0.076, 0.362, 0.719 and 1.433 mM nitrite at 30 ppt of salinity were examined for hemolymph ammonia, urea and nitrite, and nitrogenous excretion after 3, 6, 12, 24 and 48 h, respectively. Hemolymph nitrite and hemolymph urea increased directly with ambient nitrite and exposure time, whereas hemolymph ammonia was inversely related to ambient nitrite and exposure time. Specific excretions of total-N (total nitrogen), ammonia-N, urea-N and organic-N (organic nitrogen) increased directly with ambient nitrite and exposure time. The contribution of ammonia-N excretion and urea-N excretion in the total-N excreted by the control shrimp was 41.7-90.8 and 2.8-10.5%, respectively. The contribution of ammonia-N in the total-N excreted by P. japonicus decreased to 10.0 and 3.8%, when they were exposed for 24 h to 0.076 and 1.433 mM nitrite, respectively. The contribution of urea-N excretion increased to 58.7 and 21.4%, and the organic-N excretion increased to 31.3 and 74.8% in the total-N excreted by the shrimp following 24 h exposure to 0.076 and 1.433 mM nitrite, respectively. It was concluded that P. japonicus following 24 h exposure to nitrite as low as 0.076 mM increased its ammonia-N excretion by a factor of 1.9, its urea-N excretion by 200, and its organic-N excretion by 37, as compared to those in the control solution.

Fast drop movements resulting from the phase change on a gradient surface

The movement of liquid drops on a surface with a radial surface tension gradient is described here. When saturated steam passes over a colder hydrophobic substrate, numerous water droplets nucleate and grow by coalescence with the surrounding drops. The merging droplets exhibit two-dimensional random motion somewhat like the Brownian movements of colloidal particles. When a surface tension gradient is designed into the substrate surface, the random movements of droplets are biased toward the more wettable side of the surface. Powered by the energies of coalescence and collimated by the forces of the chemical gradient, small drops (0.1 to 0.3 millimeter) display speeds that are hundreds to thousands of times faster than those of typical Marangoni flows. This effect has implications for passively enhancing heat transfer in heat exchangers and heat pipes.

Significance of glutamate and dopamine neurons in the ventral pallidum in the expression of behavioral sensitization to amphetamine

To explore the significance of ventral pallidum (VP) during the amphetamine sensitization, we first investigated if there are neurochemical alterations in the VP during amphetamine withdrawal period. Chronic amphetamine-treated (5 mg/kg x 14 days) rats displayed an apparent locomotion sensitization as compared with saline controls when challenged with 2 mg/kg amphetamine at withdrawal days 10-14. A microdialysis analysis revealed that output of the dopamine metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, in the VP of amphetamine-sensitized rats increased approximately two-fold as compared to controls at both pre- and post-amphetamine challenge period. On the other hand, the in vivo glutamate output in the VP increased upon amphetamine challenge in the behaviorally sensitized rats, but not in the controls. To evaluate if drug manipulation in the VP would affect the behavioral sensitization, we treated both groups of rats with NMDA receptor antagonist, MK-801 (5 microg/microl for 5 days; bilateral) in the VP during withdrawal days 6-10. Animals were challenged with 2 mg/kg amphetamine at withdrawal day 11. The behavioral profile exhibited that MK-801 pre-treatment significantly blocked the locomotion hyperactivity in amphetamine-sensitized rats. Taken together, the current results suggest that the excitatory amino acid in the VP plays a significant role during the expression of behavioral sensitization to amphetamine.

Involvement of apoptosis during deciduomal regression in pseudopregnant hamsters effect of progesterone

We determined whether fragmentation of genomic DNA, apoptosis, occurs during deciduomal regression in pseudopregnant hamsters and the effect of progesterone on the apoptotic processes. Artificially induced deciduoma were obtained on different days of pseudopregnancy and separated into mesometrial and antimesometrial tissues. The deciduomal cell cycle progression and population profiles of both sides were compared by flow cytometry. The proportion of sub-G1 peak, which was correlated with the apoptotic cells, were about 10% on day 8 and reached to 40% in both tissues on day 10. Exogenous progesterone treatment by daily injection (2 mg; s.c.) on and after day 8 reduced the percentage of low molecular weight DNA in both tissues on day 10 and day 12 as compared to the nontreated control one, respectively. The appearance of DNA ladder was also delayed at least 24 h by progesterone administration. The intensity of DNA fragmentation was more pronounced in antimesometrial deciduoma. In situ 3'-end labeling of apoptotic cells further substantiated the apoptotic process. The apoptotic cells first appeared in the luminal region in antimesometrial deciduoma on day 8 and spreaded all over the entire deciduomal tissue on day 10. Progesterone treatment stimulated deciduomal proliferating cell nuclear antigen (PCNA) expression, maintained deciduoma until day 14 and retarded the differentiation and regeneration of the uterine epithelium.

Predicting death from ruptured abdominal aortic aneurysms

BACKGROUND

We have previously reported preoperative and immediate postoperative formulae to estimate mortality in patients with ruptured abdominal aortic aneurysms (rAAA). In this study, we prospectively compared these formulae in patients with rAAA with their actual outcomes.

METHODS

Information was collected on 134 patients from two centers over a 3-year period. Preoperative mortality risk was estimated using coefficients for age, level of consciousness, and cardiac arrest. Mortality risk in the immediate postoperative state was based on the presence of coagulopathy, ischemic colitis, prolonged requirement for inotropes, time from arrival at hospital to surgery, patient age, perioperative myocardial infarction, renal failure, and pre-operative hemoglobin level.

RESULTS

The average age was 73 years (range 30 to 92 y) and 20 of 134 (15%) patients were women. Sixty-three patients (47%) survived. For patients with a calculated preoperative mortality risk of >90%, the sensitivity, specificity, and positive and negative predictive values were 25%, 98%, 95%, and 54%, respectively. For a mortality risk >80%, these values were 37%, 94%, 87%, and 57%, respectively. For patients with an estimated immediate postoperative mortality risk > or = 90%, the sensitivity, specificity, and positive and negative predictive values were 17%, 87%, 60%, and 49%, respectively. For a predicted mortality > or = 80%, these values were 22%, 84%, 60%, and 50%, respectively.

CONCLUSIONS

Our formula for predicting mortality for preoperative rAAA patients may be useful for patients with an estimated mortality risk >/=90%, based on the high positive predictive value. The formula for immediate postoperative rAAA patients was not useful in predicting death.

Effects of intrinsic and extrinsic factors on the haemocyte profile of the prawn, Macrobrachium rosenbergii

The giant freshwater prawn Macrobrachium rosenbergii was investigated for its total haemocyte count (THC) based on season, sex, size and feeding rate. The THC, when the prawns were subjected to injections of foreign materials was also investigated. The prawns displayed the highest and lowest THC in autumn and winter respectively, with no significant difference between male and female, or among animals with a body weight range of 7-115 g. The prawns displayed the lowest THC at D3 stage, and the highest in C stage. The prawns displayed the lowest THC when they were fed at 0.1% feeding rate among feeding rates of 0.1%, 0.5%, 1.0% and 1.5% body weight x day(-1). Prawns injected with carbon powder and Enterococcus showed increased THC during the first 6 h. Prawns injected with saline and carbon powder had the lowest THC after 30 h, and recovered to the normal value after 54 h. Prawns injected with Enterococcus showed the lowest THC after 42 h, and showed delayed recovery.

Fragmentation of N-oxides (deoxygenation) in atmospheric pressure ionization: investigation of the activation process

The diagnostic fragmentation of N-oxides resulting from loss of the oxygen atom (MH+ --> MH+-O) in electrospray and atmospheric pressure chemical ionization (APCI) mass spectra was investigated. When the temperature of the heated capillary tube was elevated, the ratio of the intensity of the [MH+ -16] fragment to the precursor ion (MH+) increased. This 'deoxygenation' process was associated with thermal activation and did not result from collisional activation in the desolvation region of the API source. Although the extent of 'deoxygenation' is compound-dependent, it can provide evidence for the presence of an N-oxide in a sample and can be used to distinguish N-oxides from hydroxylated metabolites (Ramanathan et al. Anal. Chem. 2000; 72: 1352). To demonstrate the practical application of thermal fragmentation of N-oxides, liquid chromatography (LC)/APCI-MS was used to distinguish an N-oxide drug from its hydroxylated metabolite in an unprocessed rat urine sample, despite the fact that the drug and its metabolite were not fully resolved by HPLC.

Biochemical and microbial changes during the storage of minimally processed cantaloupe

The effect of storage time on pH, titratable acidity, degrees Brix, organic acids, sugars, amino acids, and color of minimally processed cantaloupe melon (Cucumis melo L. var. reticulatus Naud. cv. Mission) was determined at 4 degrees C and 20 degrees C. Changes in most of the biochemical parameters with storage time were relatively slow at the lower temperature. At 20 degrees C, a 17% loss in soluble solids and a 2-fold increase in acidity occurred after 2 days. Organic acid content also increased considerably with time at this temperature as a result of the production of lactic acid. Oxalic, citric, malic, and succinic acids were the organic acids, and glucose, fructose, and sucrose were the sugars present in the freshly cut cantaloupe. Malic acid concentration decreased concurrently with lactic acid production indicating the possible involvement of anaerobic malo-lactic fermentation along with sugar utilization by lactic acid bacteria. The effect of storage on microbial growth was determined at 4, 10, and 20 degrees C. Gram-negative stained rods grew at a slower rate at 4 degrees C and 10 degrees C than the Gram-positive mesophilic bacteria that dominated microorganism growth at 20 degrees C. Eighteen amino acids were identified in fresh cantaloupe: aspartic acid, glutamic acid, asparagine, serine, glutamine, glycine, histidine, arginine, threonine, alanine, proline, tyrosine, valine, methionine, isoleucine, leucine, phenyl alanine, and lysine. The dominant amino acids were aspartic acid, glutamic acid, arginine, and alanine. Total amino acid content decreased rapidly at 20 degrees C, but only a slight decrease occurred at 4 degrees C after prolonged storage. Changes in lightness (L), chroma, and hue at both temperatures indicate the absence of browning reactions. The results indicate the potential use of lactic acid and lactic acid bacteria as quality control markers in minimally processed fruits.

Comparison of thermal damage calculated using magnetic resonance thermometry, with magnetic resonance imaging post-treatment and histology, after interstitial microwave thermal therapy of rabbit brain

Clinical application of high-temperature thermal therapy as a treatment for solid tumours requires an accurate and close to real-time method for assessing tissue damage. Imaging methods that detect structural changes during heating may underestimate the extent of thermal damage. This is due to the occurrence of delayed damage manifested at tissue locations exposed to temperatures lower than those required to cause immediate structural changes. An alternative approach is to measure temperature and then calculate the expected damage based on the temperature history at each tissue location. Magnetic resonance (MR) imaging methods now allow temperature maps of the target and surrounding tissues to be generated in almost real-time. The aim of this work was to evaluate whether thermal damage zones calculated on the basis of MR thermometry maps measured during heating correspond to actual tissue damage as measured after treatment by histological methods and MR imaging. Four male rabbits were treated with high-temperature thermal therapy delivered in the brain by a single microwave antenna operating at 915 MHz. MR scanning was performed before, during and after treatment in a 1.5 T whole-body scanner. Temperature maps were produced using the proton resonance frequency (PRF) shift method of MR thermometry. In addition, conventional T1-weighted and T2-weighted spin-echo images were acquired after treatment. Thermal damage zones corresponding to cell death, microvascular blood flow stasis and protein coagulation were calculated using an Arrhenius analysis of the MR temperature/time course data. The calculated zones were compared with the lesions seen on histopathological examination of the brains which were removed within 6-8 h of treatment. The results showed that calculated damage zones based on MR thermometry agreed well with areas of damage as assessed using histology after heating was completed. The data suggest that real-time calculations of final expected thermal damage based on an Arrhenius analysis of MR temperature data may provide a useful method of real-time monitoring of thermal therapy when combined with conventional T2-weighted images taken after treatment.

Household exposure to passive cigarette smoking and serum micronutrient concentrations

BACKGROUND

The associations observed between passive smoking and adverse health outcomes have generated controversy. In part, this could be because the diets of passive smokers, like those of active smokers, differ from those of persons who are not exposed to cigarette smoke, especially with regard to antioxidants.

OBJECTIVE

Our objective was to assess the relation between household exposure to passive smoking and serum concentrations of retinol, tocopherols, and carotenoids.

DESIGN

A cross-sectional study was conducted in Washington County, MD, to compare exposure to passive smoking at home, recorded in a private census of county residents in 1975, with micronutrient concentrations assayed in serum collected in 1974. This comparison was possible for 1590 control subjects in nested case-control studies conducted between 1986 and 1998.

RESULTS

Among persons who were not current smokers, those who lived with smokers tended to have lower serum total carotenoid, alpha-carotene, ss-carotene, and cryptoxanthin concentrations than did those who lived in households with no smokers. There was little evidence that exposure to passive smoking was associated with reduced serum concentrations of lutein and zeaxanthin, lycopene, retinol, alpha-tocopherol, or gamma-tocopherol.

CONCLUSIONS

Among nonsmokers, exposure to passive smoking tended to be associated with lower serum concentrations of the carotenoids most strongly associated with active smoking (total carotenoids, alpha-carotene, ss-carotene, and cryptoxanthin). The associations were weaker for passive smoking than for active smoking. The consistency of the associations observed for active and passive smoking indicates that exposure to passive smoking may result in decreased circulating concentrations of selected micronutrients.

Clinical presentations of elderly patients at emergency departments: a comparison between a medical center and a community hospital

BACKGROUND

The utilization of emergency services is expected to increase in parallel with an increase of the elderly population. This article compares the elderly patient Emergency Department (ED) utilization at a 3500-bed medical center with that of a 600-bed community hospital serviced by the same group of emergency physicians.

METHODS

We retrospectively reviewed all patients over 64 years old who presented to Linkou Chang Gung Memorial Hospital (CGMH) and Keelung CGMH between July 1, 1995 and June 30, 1996 by using the 2 ED's real-time computer logs. Data comparisons included age, gender, mode of arrival, arriving source, triage category, chief complaint, impression, and final disposition.

RESULTS

There were 18,285 patients in the Linkou ED and 8038 in Keelung. Significant differences in arrival mode, arriving source, triage category, disease pattern, and final disposition were observed between the Linkou and Keelung CGMH EDs.

CONCLUSION

Significant differences reflected the different roles between the Linkou and Keelung CGMH EDs. Hospital EDs should be prepared to adapt to meet the needs of the elderly based on their roles in the medical care system, at the elderly population grows in the 21st century.

Enantioselective synthesis of (S)-ibuprofen ester prodrug in cyclohexane by Candida rugosa lipase immobilized on Accurel MP1000

An enantioselective esterification process was developed for the synthesis of 2-N-morpholinoethyl (S)-ibuprofen ester prodrug from racemic ibuprofen by using Candida rugosa lipase immobilized on Accurel MP1000 in cyclohexane. Compared with the performance of Lipase MY, the immobilized lipase possesses a higher enzyme activity and thermal stability, but with a slightly suppressed enantioselectivity. A kinetic model was proposed and confirmed from experiments, for the simulation of time-course conversions of both enantiomers at various combinations of substrate concentrations in a batch reactor. Preliminary results of employing the proposed model and the immobilized lipase in a continuous packed-bed reactor were also reported and discussed.

Carotid endarterectomy in octogenerians

PURPOSE

The purpose of this study was to determine the safety and efficacy of carotid endarterectomy (CEA) in octogenerians.

METHODS

The records of 59 CEA performed in 57 patients who were 80yr or older between April 1993 and September 1998 were reviewed. There were 33 males and 24 females with a mean age of 82. Forty-nine procedures (83%) were performed for symptomatic carotid stenosis. The perioperative mortality and morbidity including neurological events were recorded. Long term follow-up data was also obtained.

RESULTS

There were three perioperative deaths (5.1%) and three perioperative neurological events, including one stroke (1.7%) and two transient ischemic attacks (3.4%). The combined mortality and stroke rate was 6.8%. With a mean follow-up of 25+/-21months, Kaplan-Meier estimates of the 4-yr survival rate, freedom from stroke, and stroke free survival were 78, 94 and 75% respectively. For comparison, during the same time period, the same group of surgeons performed 597 CEA in patients less than 80yr of age. The perioperative mortality and stroke rate was 0.3 and 2.5% respectively, with a combined mortality and stroke rate of 2.7%. Perioperative mortality was significantly higher in patients over 80yr of age (P<0.01).

CONCLUSIONS

CEA in octogenerians is associated with a higher mortality rate than in younger patients. However, good long term survival and freedom from stroke make CEA beneficial in octogenerians. With careful patient selection and perioperative management, CEA in octogenerians is worthwhile and should be advised in selected patients.

Stereotactic radiosurgery in the treatment of metastatic disease to the brain

We review 190 consecutive patients with 434 metastatic tumors treated by gamma knife stereotactic radiosurgery, from August 1994 to February 1999. Median actuarial survival for all patients was 34 weeks. Factors correlated with significantly improved survival included controlled systemic disease and nonmelanoma histology. We found that no significant survival benefit could be discerned from adjuvant whole brain radiotherapy in this patient group. Survival was not statistically different for patients initially presenting with 1-4 metastases at initial treatment.

Proposed flow cytometric reference method for the determination of erythroid F-cell counts

BACKGROUND

Quantitation of adult erythrocytes (RBC) containing fetal hemoglobin (F cells) is of potential clinical utility in evaluating erythropoietic disorders, such as myelodysplasia and hemoglobinopathies, and in monitoring F-cell augmenting therapy. F-cell counting methodologies include fluorescence microscopy and flow cytometry. Previous flow cytometric methods have employed an isotype antibody control to distinguish F cells from non-F cells. We investigated the feasibility of using the orange autofluorescence signal (FL2) in glutaraldehyde-fixed RBC to substitute for fluorescein isothiocyanate (FITC)-labeled isotype control antibody use in F-cell quantitation.

METHODS

Our previously published method for fetal red cell detection in fetomaternal hemorrhage was used, employing a FITC-labeled anti-hemoglobin F (HbF) monoclonal antibody reagent. Blood samples with varying F-cell counts were quantitated for F cells using both immunofluorescence microscopy and flow cytometry comparing FITC-labeled isotype to FL1 thresholding defined by FL2 autofluorescence.

RESULTS

F cell percentages obtained by using an FL2 defined threshold for FL1 gating correlated well with expected values in diluted blood samples (r(2) = 0.994, slope = 1. 019, intercept = 0.24), values obtained using an isotype control (r(2) = 0.996, slope = 1.012, intercept = -0.17), and microscopic immunofluorescence counts (r(2) = 0.989, slope = 0.999, intercept = -0.72). F-cell quantitation by the isotype control and FL2 autofluorescence methods was also comparable in 40 blood samples (r(2) = 0.994, slope = 1.014, intercept = 0.03). Intra-assay, interobserver, and interinstrument precision with this autofluorescence gating method exhibited low imprecision (coefficient of variation <14%).

CONCLUSION

This novel method is a more objective and less laborious alternative for F-cell quantitation by flow cytometry compared to using an isotype control or microscopy, thereby providing a more robust methodology for clinical studies and consideration as a laboratory reference method for F-cell counting.

Stereotaxy, navigation and the temporal concatenation

Nautical and cerebral navigation share similar elements of functional need and similar developmental pathways. The need for orientation necessitates the development of appropriate concepts, and such concepts are dependent on technology for practical realization. Occasionally, a concept precedes technology in time and requires periods of delay for appropriate development. A temporal concatenation exists where time allows the additive as need, concept and technology ultimately provide an endpoint of elegant solution. Nautical navigation has proceeded through periods of dead reckoning and celestial navigation to satellite orientation with associated refinements of instrumentation and charts for guidance. Cerebral navigation has progressed from craniometric orientation and burr hole mounted guidance systems to simple rectolinear and arc-centered devices based on radiographs to guidance by complex anatomical and functional maps provided as an amalgam of modern imaging modes. These maps are now augmented by complex frame and frameless systems which allow not only precise orientation, but also point and volumetric action. These complex technical modalities required and developed in part from elements of maritime navigation that have been translated to cerebral navigation in a temporal concatenation.