Identification of a calcium-binding protein as a calcium-dependent regulator of brain adenylate cyclase

An activating factor of adenylate cyclase (EC 4.6.1.1) HAS BEEN OBTAINED FROM DETERGENT-DISPERSED PREPARATIONS OF PORCINE CEREBRAL CORTEX BY COLUMN CHROMATOGRAPHY ON ECTEOLA-cellulose. The factor was identified by acrylamide gel electrophoresis and by enzyme activation studies as the Ca2+-binding protein that regulates the activity of a brain cyclic nucleotide phosphodiesterase. This Ca2+-binding protein confers a Ca2+-dependent activation upon the adenylate cyclase, which is reversed by the subsequent addition of egta in excess of the free Ca2+. It is proposed that this Ca2+-dependent regulator controls enzymatic activities responsible for the synthesis of adenosine 3':5'-monophosphate and for the hydrolysis of guanosine 3':5'-monophosphate.

Clinical features and risk factors of pulmonary oedema after enterovirus-71-related hand, foot, and mouth disease

BACKGROUND

In Taiwan, from April to July, 1998, an epidemic of hand, foot, and mouth disease associated with enterovirus 71 (EV71) occurred with fatal complications. We did a clinical study of EV71-related diseases in Taiwan.

METHODS

We studied 154 children with virus-culture confirmed EV71 infection. Children were divided into three groups: 11 patients with pulmonary oedema; 38 patients with central nervous system (CNS) involvement and no pulmonary oedema; and 105 children without complications. We compared the clinical features, laboratory findings, risk factors, and outcome among these three groups.

FINDINGS

Nine children with pulmonary oedema had hand, foot, and mouth disease, one had herpangina, and one had febrile illness with eight children with limb weakness and one with limb hypesthesia. All children had had sudden onset of tachycardia, tachypnoea, and cyanosis 1-3 days after onset of the disease. Nine of 11 children died within 12 h of intubation; one child was braindead within 15 h and died 17 days after intubation; one child was in deep coma and died 3 months later. In children with CNS complication and no pulmonary oedema, one child died of pneumonia after 4 months of ventilator support and four children had sequelae. All 105 children without complications recovered. There was a significant association between CNS involvement and pulmonary oedema (odds ratio 12.4 [95% CI 2.6-60.1], p=0.001). Risk factors for pulmonary oedema after CNS involvement were hyperglycaemia, leucocytosis, and limb weakness. Hyperglycaemia was the most significant prognostic factor for pulmonary oedema (odds ratio 21.5 [3-159], p=0.003).

INTERPRETATION

EV71 can cause hand, foot, and mouth disease, CNS involvement with severe sequelae, and fatal pulmonary oedema. Hyperglycaemia is the most important prognostic factor.

Comparison of enterovirus 71 and coxsackie-virus A16 clinical illnesses during the Taiwan enterovirus epidemic, 1998

OBJECTIVES

To compare enterovirus 71 (EV 71) with coxsackievirus A16 (Cox A16) clinical illness in patients at Chang Gung Children's Hospital during Taiwan's enterovirus epidemic of 1998.

METHODS

With the use of the immunofluorescence assay and neutralization test, 177 cases of EV 71 and 64 cases of Cox A16 illness were confirmed from April to September, 1998. The clinical signs and symptoms, complications and case fatality rates were compared.

RESULTS

Three-fourths of the cases were younger than 3 years of age, and the ratio of males to females was 1.3 in the EV 71 group and 1.2 in the Cox A16 group. In the EV 71 group 120 (68%) cases were uncomplicated, including 94 cases of hand, foot and mouth disease and 15 cases of herpangina, and 57 (32%) cases had complications, including 13 (7.3%) cases of aseptic meningitis, 18 (10%) cases of encephalitis, 4 (2.3%) cases of polio-like syndrome, 8 (4.5%) cases of encephalomyelitis and 12 (6.8%) cases of fatal pulmonary edema. Fourteen (7.9%) patients died, including 12 cases of pulmonary edema and 2 cases of encephalitis; seven (4%) patients had sequelae. By contrast, 60 (94%) of the 64 cases of Cox A16 infection were uncomplicated and only 4 (6.3%) cases were complicated by aseptic meningitis; no fatalities or sequelae were observed. By multivariate analysis vomiting (P = 0.01) and fever higher than 39 degrees C plus lasting longer than 3 days (P = 0.02) were significantly more frequent in the EV 71 group.

CONCLUSION

EV 71 illness is more severe with significantly greater frequency of serious complications and fatality than is illness caused by Cox A16.

Relationship between serotypes and genotypes based on the hypervariable region of the S1 gene of infectious bronchitis virus

To group infectious bronchitis virus (IBV) isolates, a genetic grouping method based on hypervariable region 1 (HVR 1, nucleotides 168 to 197) was compared with that based on the whole S1 gene. Both methods resulted in the same grouping data. So the grouping method based on HVR 1 could represent the grouping method based on the whole S1 gene. Taiwan isolates could not be placed within the existing groups. In order to test the correlation between genotype and serotype, a one-way neutralization test was used to compare 9 Taiwan isolates selected from different genotypes with Massachusetts (Mass) (H120) and Connecticut (Conn) standard strains. In addition, a two-way cross-neutralization test was performed in embryonated eggs with the beta method (constant-virus, diluted-serum) and the reciprocal neutralization titers were calculated to give the relatedness (r) values. The results of two kinds of neutralizing tests showed that the serotypes of 9 isolates were different from Mass or Conn. Based on the r-values, 9 isolates were divided into two serotypes which were correlated with their genotypes. From pathogenicity tests, IBV Taiwan isolates could be divided into high, intermediate, and low pathogenicity according to their pathogenicity indexes. However, no relationship exists between pathotype and genotype. In conclusion, the genetic typing method based on HVR 1 can be used for typing IBV isolates.

Pharmacokinetics and dose proportionality of ketoconazole in normal volunteers

Ketoconazole is an orally effective, broad-spectrum, systemic antifungal agent. The pharmacokinetics and bioavailability of ketoconazole given as a 200-mg single dose in a tablet, suspension, or solution were studied in 24 fasting healthy males by using a crossover design. Levels of ketoconazole in plasma were determined for up to 48 h by a sensitive reverse-phase high-performance liquid chromatography method. The absorption of ketoconazole was rapid, with mean maximum concentrations of the drug in plasma of 4.2, 5.0, and 6.2 micrograms/ml attained at 1.7, 1.2, and 1.0 h, respectively, after administration of the tablet, suspension, and solution, respectively. The mean distribution and elimination half-life values were 1.5 to 1.7 and 7.5 to 7.9 h, respectively. The mean oral clearance of the solution dose was 209 (+/- 82.9 [standard deviation]) ml/min, and the mean apparent volume of distribution was 88.31 (+/- 68.72) liters. The relative bioavailabilities for the tablet and suspension were 81.2 (+/- 33.5) and 89.0 (+/- 23.1)%, respectively, of that of the solution. The data indicated the bioequivalence of the tablet to the suspension and of the suspension of the solution. Dose proportionality of ketoconazole was also studied in 12 volunteers after they received solution doses of 200, 400, and 800 mg. Linear correlations between the dose and the maximum concentration of the drug in plasma, the time to the maximum concentration, and the area under the concentration-time curve were observed. However, the increase in the area under the curve was more than proportional to the dose given. The levels in plasma seemed to decay at a lower rate after 400- and 800-mg doses. The mean oral clearance decreased from 244.9 to 123.6 and 80.0 ml/min, respectively, as the dose increased from 200 to 400 and 800 mg. The apparent dose-dependent kinetics may have been due to the presystemic elimination and capacity-limited hepatic metabolism which become saturated at higher doses.

Collagen and elastin in the obstructed fetal bladder

Histological findings of muscle, collagen and elastin in obstructed fetal bladders were compared with those of age-matched controls. Muscle thickness was markedly increased, however, the relative collagen content in the muscle was decreased. The ratio of thick-to-thin collagen fibers was markedly increased as was the amount of elastin. These findings suggest that the ratio of thick collagen to elastin has an important role in determining the compliance of the obstructed fetal bladder.

Outbreak of Candida parapsilosis fungemia in neonatal intensive care units: clinical implications and genotyping analysis

During a 5-month period, 17 infants hospitalized in neonatal intensive care units of a medical center and a branch hospital developed 18 episodes of Candida parapsilosis fungemia. The mean age at onset was 35 days. Prior to fungemia, all the infants had received hyperalimentation and antibiotics, and 15 infants had had central venous catheters. The presenting symptoms were variable but only vague in 40% of the episodes. Despite administration of antifungal agents, subsequent eradication of fungemia was achieved in only two-thirds of the episodes. None of the environmental samples was positive for C. parapsilosis, while 20% of hand-washing samples of staff working in both units yielded this microorganism. Four genotypes with two main types were identified from 14 outbreak strains and eight genotypes from 14 hand-washing strains, with one type predominant. The results suggest that C. parapsilosis fungemia increases the morbidity and mortality of neonates but does not cause acute lethal events. The outbreak was caused by two main genotypes, possibly via cross-infection by the hands of health care workers.

Association of fungal colonization and invasive disease in very low birth weight infants

BACKGROUND

Fungi are common pathogens of nosocomial infections in the very low birth weight (VLBW) infants. The purpose of this study was to investigate the fungal colonization rate in VLBW infants and the association between fungal colonization and systemic fungal diseases.

MATERIALS

Between January 1, 1996, and December 31, 1996, 116 infants with birth weight < 1500 g admitted to the neonatal intensive care unit of Chang Gung Children's Hospital in the first day of life were included in this prospective study.

METHODS

Cultures from oropharynx, rectum, skin (groin and axilla), bag urine and endotracheal aspirates were obtained in the first 24 h after birth and weekly thereafter throughout their neonatal intensive care unit stay. Medical records were reviewed weekly.

RESULTS

Fungal colonization was detected in 25 infants, among whom 17 infants developed colonization by 2 weeks of life. Candida albicans (61%) and Candida parapsilosis (29%) were the 2 most common organisms. The rectum (76%) was the most frequent site of colonization. Factors significantly associated with colonization were prolonged administration of antibiotic therapy, parenteral nutrition and intralipid emulsion. Three of 116 infants developed fungemia. The association between colonization and subsequent fungemia was demonstrated in 1 infant, representing 4% of colonized infants.

CONCLUSION

Fungal colonization was detected in one-fifth of VLBW infants and represents a risk factor for fungemia. Because disease occurred in the absence of apparent colonization, factors other than colonization may contribute to invasive candidiasis.

Postnatal depression -- biological or cultural? A comparative study of postnatal women in the UK and Taiwan

AIM

The aim of the study was to compare the factors which are associated with postnatal depression in the UK (United Kingdom) and Taiwan.

BACKGROUND/RATIONALE

A comparative study of postnatal women in the UK and Taiwan was undertaken to investigate postnatal care and the prevalence of postnatal depression.

DESIGN/METHODS

The Edinburgh Postnatal Depression Scale (EPDS) was used to determine the prevalence of postnatal depression. A semistructured interview and validated questionnaire were used to collect data on maternal satisfaction with postnatal care and the factors associated with postnatal depression. A one in three random sample of women from two community midwife teams in Sheffield, UK and three public health stations in Keelung, Taiwan took part in the study.

RESULTS/FINDINGS

Fifty (94% response rate) women from Sheffield and 101 (83% response rate) women from Keelung, who were at low risk for maternal or foetal problems during labour and the postnatal period, agreed to participate. The prevalence of postnatal depression in the British and Taiwanese women was almost equal; 18% in the UK and 19% in Taiwan. In Taiwan, the prevalence of postnatal depression had a negative association with relationship with partner (Spearman correlation=-0.34, P < 0.001) and self-confidence (Spearman correlation=-0.28, P < 0.01, Spearman correlation). In addition Taiwanese women who felt more anxious after birth (10.9 +/- 7.9, P < 0.001, t-test) had a higher chance of postnatal depression. In the UK, there was a significant negative association between adaptation to the new role of motherhood and score on the EPDS (Spearman correlation=-0.47, P < 0.001). The overall scores for maternal satisfaction were 28.1 and 24.3 in the UK and Taiwan, respectively (P < 0.001, t-test). British women reported a better quality of care during the postnatal period in terms of emotional support and physical care.

CONCLUSIONS

The findings of this study suggest that further cross cultural investigation could shed light on the relative balance of biological and cultural factors which may be associated with the onset of postnatal depression. As the prevalence of postnatal depression is similar in both cultures despite large differences in culture and postnatal care systems, some support is given to a hypothesis that postnatal depression has at least some biological determinants as well as cultural/social ones.

A Natural Compound (Ginsenoside Re) Isolated from Panax ginseng as a Novel Angiogenic Agent for Tissue Regeneration

PURPOSE

The primary challenge for tissue engineering is to develop a vascular supply that can support the metabolic needs of the engineered tissues in an extracellular matrix. In this study, the feasibility of using a natural compound, ginsenoside Re, isolated from Panax ginseng in stimulating angiogenesis and for tissue regeneration was evaluated.

METHODS

Effects of ginsenoside Re on the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were examined in vitro. Additionally, angiogenesis and tissue regeneration in a genipin-fixed porous acellular bovine pericardium (extracellular matrix; ECM) incorporated with ginsenoside Re implanted subcutaneously in a rat model were investigated. Basic fibroblast growth factor (bFGF) was used as a control.

RESULTS

It was found that HUVEC proliferation, migration in a Transwell plate, and tube formation on Matrigel were all significantly enhanced in the presence of bFGF or ginsenoside Re. Additionally, effects of ginsenoside Re on HUVEC proliferation, migration, and tube formation were dose-dependent and reached a maximal level at a concentration of about 30 microg/ml. The in vivo results obtained at 1 week postoperatively showed that the density of neocapillaries and the tissue hemoglobin content in the ECMs were significantly enhanced by bFGF or ginsenoside Re. These results indicated that angiogenesis in the ECMs was significantly enhanced by loading with bFGF or ginsenoside Re. At 1 month postoperatively, vascularzied neo-connective-tissue fibrils were found to fill the pores in the ECMs loaded with bFGF or ginsenoside Re.

CONCLUSIONS

The aforementioned results indicated that like bFGF, ginsenoside Re-associated induction of angiogenesis enhanced tissue regeneration, supporting the concept of therapeutic angiogenesis in tissue-engineering strategies.

Different proinflammatory reactions in fatal and non-fatal enterovirus 71 infections: implications for early recognition and therapy

AIM

The mechanism of pulmonary oedema, a life-threatening manifestation of enterovirus 71 (EV71) encephalitis, is unclear. Our aim was to assess the relationship of proinflammatory cytokines to EV71-related pulmonary oedema.

METHODS

Proinflammatory responses in 33 EV71 patients with various complications and 21 normal healthy children were measured using an enzyme-linked immunosorbent assay.

RESULTS

EV71 patients with both encephalitis and pulmonary oedema were found to have much higher levels of blood interleukin-6 (IL-6) (947 +/- 1239 vs 4.9 +/- 3.1 pg/ml, p = 0.0003), tumour necrosis factor-alpha (TNF-alpha) (22.4 +/- 29.5 vs 5.3 +/- 1.0 pg/ml, p = 0.0035), interleukin Ibeta (IL-1beta) (48.4 +/- 85.2 vs 4.9 +/- 10.1 pg/ml, p = 0.01), white blood cell count (28.3 +/- 7.6 vs 15.5 +/- 6.8 10(9)/L, p > or = 0.0001) and blood glucose (501 +/- 186 vs 165 +/- 117 mg/dL, p = 0.0009) than patients with EV71 encephalitis alone. In fact, the cytokine levels in patients with encephalitis only or in those without complications were not significantly different from the levels found in normal children. The sensitivity, specificity, positive and negative predictive values of IL-6 > 70 pg/ml for EV71 encephalitis with pulmonary oedema were all 100%.

CONCLUSION

Patients with EV71-related encephalitis combined with pulmonary oedema were found to have significantly elevated levels of proinflammatory cytokines and the best predictor for this complicated condition was found to be the level of serum IL-6.

Nutritional status of mechanically ventilated critically ill patients: comparison of different types of nutritional support

Malnutrition is a common problem in hospitalized patients. Early assessment of nutritional status may help in identifying patients for whom nutritional interventions are needed. The purpose of this study was to assess and compare the nutritional status of mechanically ventilated critically ill patients who were receiving nutritional support. Forty-nine patients were divided into either enteral nutrition, total parenteral nutrition or combined (enteral plus total parenteral nutrition) groups. Anthropometric and biochemical measurements, and medical status (APACHE II score) were assessed at the 1st day and 14th day of admission in the intensive care unit (ICU) of Taichung Veteran General Hospital. The length of ventilator dependency was significantly positively correlated with calorie and carbohydrate intake in the pooled group. Patients receiving enteral and combined nutrition showed significantly lower anthropometric measurements at the 14th day after admission. Patients in all groups had abnormal mean biochemical values at the 1st day of admission. Subjects in the combined group showed a significant increase in prealbumin and the Maastricht Index levels after 14 days. Patients in all three groups were malnourished when admitted to the ICU. Patients showed a slightly improvement of nutritional status after receiving nutritional support for 14 days.

Collagen and elastin in the normal fetal bladder

The development of muscle, collagen and elastic fibers was studied histologically in 15 human fetal bladder specimens. Muscle thickness progressively increased and the relative collagen content in the muscle decreased during gestation. The ratio of thick-to-thin collagen fibers also decreased, whereas elastic fibers increased. These findings document the normal process of maturation of the fetal bladder and serve as a basis for comparison with congenitally obstructed fetal bladders.

Normal values for single exhalation diffusing capacity and pulmonary capillary blood flow in sitting, supine positions, and during mild exercise

Previous approaches to the measurements of pulmonary diffusing capacity (DL) and pulmonary capillary blood flow (QC) utilized either the rebreathing or the single inhalation technique in conjunction with radioisotope gas and mass spectrometry. In the present study, we utilized a newly developed rapid infrared analyzer in conjunction with the slow single exhalation technique on 100 healthy volunteers to establish normal values for DL and QC under sitting, supine, and exercise conditions. The exercise level was determined by a target heart rate: HRex = ([HRmax - HRrest]/3) + HRrest. Prediction equations based on regressions on age, sex, height, or weight were then computed for sitting, supine, and exercise values. We found that mean DL and QC increased by approximately 12 percent and 8 percent, respectively, from sitting to supine posture, and by approximately 30 percent and 100 percent, respectively, from sitting (rest) to mild exercise. These results provided a database for further studies in the single exhalation method in various clinical settings.

Lactobacillus kunkeei sp. nov.: a spoilage organism associated with grape juice fermentations

A Gram-positive rod was isolated from a commercial grape wine undergoing a sluggish/stuck alcoholic fermentation. The organism produced L-lactic acid from glucose, possessed weak catalase activity, and fermented relatively few carbohydrates, i.e. glucose, fructose, sucrose, raffinose (weakly) and mannitol. The 16S rRNA gene sequence analysis revealed that the isolate was phylogenetically a member of the genus Lactobacillus and formed a distinct subline within the Lact. casei cluster of species. Based on phenotypic and phylogenetic evidence, a new species is proposed, Lact. kunkeei. The type strain of Lact. kunkeei is ATCC 700308.

Clinical and radiographic spectrum of septic pulmonary embolism

AIMS

To review the clinical presentation, radiographic findings, and outcome of therapy in children with septic pulmonary embolism.

METHODS

Retrospective analysis of patients in a tertiary paediatric facility in northern Taiwan.

RESULTS

Ten children were identified with septic pulmonary emboli in a four year retrospective chart review between 1998 and 2001. Seven were immunocompetent, two were premature infants, one had beta thalassemia major. Seven had community acquired staphylococcal infections and bacteraemia, of which six were methicillin resistant Staphylococus aureus (MRSA) isolates. Five had soft tissue infections, two bone infections, one suppurative otitis media, one catheter related infection, and one unknown foci of infection. Multiple and bilateral nodular pulmonary parenchymal lesions were common on plain chest radiographs, but chest computed tomography scans showed the additional findings of a "vessel sign" and central cavitations, confirming the existence of septic pulmonary embolism.

CONCLUSIONS

Community acquired MRSA infections occurred in seven patients with septic pulmonary embolism but without predisposing high risk factors. Critically ill children with skin, soft tissue, or bone infections, when associated with septic pulmonary embolism in an area with a high rate of MRSA, should be empirically treated with glycopeptides (such as vancomycin or teicoplanin) before susceptibility results are known, in order to minimise morbidity and avoid mortality.

Social modulation during songbird courtship potentiates midbrain dopaminergic neurons

Synaptic transmission onto dopaminergic neurons of the mammalian ventral tegmental area (VTA) can be potentiated by acute or chronic exposure to addictive drugs. Because rewarding behavior, such as social affiliation, can activate the same neural circuitry as addictive drugs, we tested whether the intense social interaction of songbird courtship may also potentiate VTA synaptic function. We recorded glutamatergic synaptic currents from VTA of male zebra finches who had experienced distinct social and behavioral conditions during the previous hour. The level of synaptic transmission to VTA neurons, as assayed by the ratio of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) to N-methyl-D-aspartic acid (NMDA) glutamate receptor mediated synaptic currents, was increased after males sang to females, and also after they saw females without singing, but not after they sang while alone. Potentiation after female exposure alone did not appear to result from stress, as it was not blocked by inhibition of glucocorticoid receptors. This potentiation was restricted to synapses of dopaminergic projection neurons, and appeared to be expressed postsynaptically. This study supports a model in which VTA dopaminergic neurons are more strongly activated during singing used for courtship than during non-courtship singing, and thus can provide social context-dependent modulation to forebrain areas. More generally, these results demonstrate that an intense social encounter can trigger the same pathways of neuronal plasticity as addictive drugs.

Development of a novel bioreactor for the mechanical loading of tissue-engineered heart muscle

OBJECTIVE

In this study, we describe a novel bioreactor system to deliver controlled stretch protocols to bioengineered heart muscle (BEHM) constructs. Our primary objective was to evaluate the effect of mechanical stretch on the contractile properties of three-dimensional cardiac constructs in vitro.

METHODS

BEHMs were formed by culturing primary neonatal cardiac myocytes in a fibrin gel using a method previously developed in our laboratory. A custom bioreactor system was designed using SolidWorks (Concord, MA) and structural components were manufactured using fusion deposition modeling. We utilized the bioreactor to evaluate the effect of 2-, 6-, and 24-hour stretch protocols on the stretch-induced changes in contractile function of BEHMs.

RESULTS

We were able to demonstrate compatibility of the bioreactor system with BEHMs and were able to stretch all the constructs with zero incidence of failure. We found that loading the constructs for 2, 6, and 24 hours during a 24-hour period using a stretch protocol of 1 Hz, 10% stretch did not result in any significant change in the active force, specific force, pacing characteristics, and morphological features.

CONCLUSIONS

In this study, we demonstrate compatibility of a novel bioreactor system with BEHMs and the stability of the BEHMs in response to stretch protocols.

Antimicrobial susceptibilities of Campylobacter jejuni and coli by using E-test in Taiwan

To report the in vitro antibiotic susceptibility of Campylobacter species, we determined the MICs of 6 antibiotics by E-test for 93 human clinical strains and 35 chicken strains. The 6 antimicrobial agents tested were gentamicin, erythromycin, clindamycin, tetracycline, ciprofloxacin, and nalidixic acid. Isolates from humans were significantly more susceptible than chicken strains to erythromycin, clindamycin and ciprofloxacin. Nearly all of the human and chicken strains were susceptible to gentamicin. Among human isolates of C. jejuni, cross-resistance between nalidixic acid and ciprofloxacin was found in 66% of the strains, but none of the nalidixic acid-susceptible strains was resistant to ciprofloxacin. The higher prevalence of ciprofloxacin resistance in this area may be attributable to the large amount use of quinolones in poultry. Because of the high resistance rates of chicken isolates to the commonly used antimicrobial agents, it is necessary to create innovative methods to limit the inappropriate use of antibiotics in poultry in order to prevent the spread of the drug-resistant strains to humans.

Pharmacokinetics of chlorpheniramine after intravenous and oral administration in normal adults

Plasma and urinary levels of chlorpheniramine (CPM) and its 2 demethylated metabolites were measured by HPLC after i.v. and oral dosing. In 5 mg (maleate) i.v. bolus studies in 2 subjects, plasma CPM levels were fitted to triexponential equations with terminal half-lives (t 1/1) of 23 and 22 h and area of 3.6 and 3.21/kg, respectively. Intravenous data predicted hepatic blood extraction ratios for the 2 subjects to be 0.06 and 0,07, respectively. Absolute bioavailability from oral solution (10 mg) was 59 and 34%, and from tablets (8 mg) 44 and 25%, respectively, indicating extensive gut first-pass metabolism. Mean t 1/2 from 7 oral fasting studies in 5 subjects was 28 h (19-43 h). Mean absorption lag time was 0.7 h (0.4-1.3 h), and mean peak time was 2.8 h (2-4 h). In 2 subjects, 6 mg solutions were given every 12 h for 9 doses; good correlation between single and multiple dose kinetics was found. Significant accumulation was demonstrated in simulation studies with frequent daily dosing. Estimated accumulation ratios vary from 4.1 to 9.4 (mean 6.5). The t 1/2 from urinary data (collected for 12 days) was consistent with plasma data. The above results suggest the need to reexamine the current practice of frequent daily dosing and the use of sustained or controlled release dosage forms of this drug. The possible cause of reduced plasma clearance of CPM in renal patients is discussed.

n-3 fatty acids decrease colonic epithelial cell proliferation in high-risk bowel mucosa

The n-3 fatty acids (C20:5, eicosapentaenoic acid; c22:6, docosahexaenoic acid) may be important in the development, growth, and metastasis of colon cancer, a leading cause of death in North America. Patients who have had a bowel neoplasm have a high risk of developing a second neoplasm, and this risk is associated with a high percentage of cells correspond to the S phase of bromodeoxyuridine (BrdUrd) labeling in mucosal epithelial cells. To determine the effect of n-3 fatty acid supplementation on DNA synthesis of rectal mucosa, patients with stage 1 or stage 2 colon carcinoma or adenomatous polyps were randomized to consume either 9 g/d n-3 fatty acid capsules or 9 g/d placebo capsules. Plasma phospholipid fatty acid analysis and proctoscopic mucosal biopsies were performed at baseline, 3, and 6 mon. Colonic crypts were isolated from the mucosa, disassociated with enzymes, and incubated with BrdUrd, and %S phase was measured by flow cytometry. The plasma phospholipid n-6/n-3 ratio was determined by gas chromatography. Supplement compliance was assessed by plasma phospholipid n-6/n-3 ratio. Mean capsule consumption in these two group was 82%. Prior to supplementation, there were no significant differences in the %S phase and the plasma n-6/n-3 ratio between these groups. Patients whose colonic epithelial cells indicated hyperproliferation at baseline showed a strongly positive correlation to the %S phase of BrdUrd uptake and the n-6/n-3 ratio. There was no significant change after n-3 treatment in patients with low baseline. Those in the placebo group showed no significant difference in n-6/n-3 ratio, although there was an increase in the %S phase of BrdUrd uptake at 6 mon. The n-3 group did not have significant side effects, and polyps were not found after completing 12 mon of n-3 fatty acid supplementation. This study suggests that n-3 fatty acid may be a useful chemopreventive agent in some patients as reflected in a plasma biomarker of colon tumor growth and metastasis. A low plasma phospholipid n-6/n-3 fatty acid ratio may serve as a nutritional marker that is associated with colonic epithelial cell hyperproliferation in the n-3-supplemented group as compared with the placebo group. Characteristics of mucosal proliferation at baseline may be a crucial factor for the effect of n-3 fatty acid supplementation.