Clinical features and characteristics of pediatric patients with COVID-19 infection: Experiences in a Tertiary Taiwan Hospital

Coronavirus disease 2019 (COVID-19) patients have distinct clinical features in the pediatric groups. However, there is a paucity of research focused on clinical manifestation within pediatric group in Taiwan. This study is to conduct a retrospective study of the clinical features of COVID-19 in Taiwan pediatric patients. A retrospective study was conducted on pediatric patients (Aged ≤ 18 years) in a Northern Taiwan hospital from May 1st, 2021 to June 30th, 2021. Thirty-eight patients were included from emergency room. They were laboratory confirmed COVID-19 through specimens from nasopharyngeal swab by real-time reverse-transcription polymerase chain reaction (RT-PCR). Data including RT-PCR cycle threshold (Ct) values, clinical and epidemiological features were collected and analyzed. Thirty-eight patients aged from 7-month to 18-year-old were included. The median age of patients was 15-year-old. The patients had sex ratio of 23 males to 15 females. More than half patients were infected from family members. Asymptomatic patients were 47.37%. In the symptomatic patients, fever (34.21%) was the most predominant symptom. Cough, nasal obstruction and sore throat were also common. Asymptomatic children had significantly higher Ct-values than symptomatic children, and diagnosed patients with Ct-values more than 19 were associated with asymptomatic infection (P = .0084). Ct-values higher than 19 were associated with asymptomatic infection, which may be a predictor of pediatric disease severity. Our results highlight the distinct clinical manifestations and outcomes in pediatric COVID-19 patients. Compared to the adults, pediatric patients aged ≤ 18 years with COVID-19 in Taiwan mainly had mild disease.

Clinical significance and intestinal microbiota composition in immunocompromised children with norovirus gastroenteritis

Background

Norovirus (NoV) infection is common in pediatric patients with immunodeficiency and is more likely to cause severe disease. Objective Our study aims to figure out the clinical differences and distribution of intestinal microbiota in immunocompromised children with NoV gastroenteritis.

Methods

Pediatric patients admitted to Shang-Ho Hospital with diagnosis of acute gastroenteritis including different immune status were enrolled and their medical records were reviewed. NoV gastroenteritis was validated using RT-PCR molecular methods. Viral shedding period was determined by real-time RT-PCR assays. Intestinal microbiota enrichment analysis was carried out by next generation sequencing after fecal DNA extraction and subsequent Linear Discriminant Analysis (LDA) Effect Size (LEfSe) method.

Results

Significantly higher frequency of diarrhea [mean, (IQR), 3.8 (3–5) /day] and longer viral shedding time [mean, IQR, 8.5 (5–13) days] was found in immunocompromised NoV infections than in immunocompetent patients without NoV infections (p = 0.013*) and immunocompetent patients with NoV infections (p = 0.030**). The fever prevalence was significantly lower in immunocompromised NoV infections than in different immune or infection status. Intestinal microbiota metagenomics analysis showed no significant community richness difference while the LEfSe analysis showed a significant difference in commensal richness at the phylum level, the family level, and the genus level in patients under different immune status.

Conclusion

We evaluated the clinical significances and microbiota composition in immunocompromised children with norovirus gastroenteritis. This will further facilitate studies of the interaction between the intestinal microbiota in such patients with precise determination of their bacterial infection control and probiotic supplements strategy.

Epidemiology, Clinical Features, and Unusual Complications of Norovirus Infection in Taiwan: What We Know after Rotavirus Vaccines

Noroviruses (NoVs) are one of the emerging and rapidly spreading groups of pathogens threatening human health. A reduction in sporadic NoV infections was noted following the start of the COVID-19 pandemic, but the return of NoV gastroenteritis during the COVID-19 pandemic has been noted recently. Research in recent years has shown that different virus strains are associated with different clinical characteristics; moreover, there is a paucity of research into extraintestinal or unusual complications that may be associated with NoV. The genomic diversity of circulating NoVs is also complex and may vary significantly. Therefore, this short narrative review focuses on sharing the Taiwan experience of NoV infection including epidemiology, clinical features, and complications following suboptimal rotavirus immunization in Taiwan (after October 2006). We also highlight the unusual complications associated with NoV infections and the impacts of NoV infection during the COVID-19 pandemic in the literature for possible future research directions. To conclude, further research is needed to quantify the burden of NoV across the spectrum of disease severity in Taiwan. The evidence of the connection between NoV and the unusual complications is still lacking.

The impact of rotavirus vaccination in the prevalence of gastroenteritis and comorbidities among children after suboptimal rotavirus vaccines implementation in Taiwan: A population-based study

In Taiwan, rotavirus vaccination was implemented in 2006 in the private sector. The population-based impact of rotavirus vaccination on gastroenteritis and comorbidities of children remains under-investigated.We analyzed the annual prevalence of rotavirus-related disease, including gastroenteritis, convulsions, epilepsy, type I diabetes mellitus, intussusception, and biliary atresia among children under 5 years of age. Data were collected from Taiwan's National Health Insurance Research Database, a nationwide population-based database. A 16-year retrospective cohort study was conducted between 2000 and 2015.Among children <5 years of age, the prevalence of gastroenteritis decreased after 2012 (44,259.69 per 100 thousands) and remained lower through 2015 (39,931.11per 100 thousands, P < .001). The prevalence of convulsions rose steadily and significantly from 2007 (775.90 per 100 thousands) to 2015 (962.17 per 100 thousands, P < .001). The prevalence of epilepsy decreased significantly until reaching a nadir in 2013 (from 501.56 to 293.53 per 100 thousands, P < .001). The prevalence of biliary atresia tended upward, and surged suddenly in 2007 with a peak in 2013 (18.74 per 100 thousands). Among infants (<1 year of age) from 2000 to 2015, the prevalence of gastroenteritis declined steadily, and more rapidly after 2007 (22,513 to 17,285 per 100 thousands).In Taiwan, after introducing rotavirus vaccination, gastroenteritis in young children decreased, especially in infancy. However, gastroenteritis is still common in children, given other emerging pathogens. Our results highlight the impact of rotavirus vaccines on children's health in Taiwan and provide indications for future preventive medicine and healthcare strategies in children.

A reappraisal of the prevalence of pediatric hypertension through a nationwide database in Taiwan

Hypertension in childhood and adolescence is associated with adult cardiovascular morbidity and mortality. However, the reported prevalence of pediatric hypertension varies considerably. We conducted a pioneer nationwide population-based study to investigate the prevalence of hypertension among children and adolescents. Pediatric patients who had been diagnosed with hypertension between 2000 and 2013 were selected from the National Health Insurance Research Database in Taiwan. Other metabolic syndrome-related diseases that would increase cardiovascular risk, including diabetes mellitus (DM), hyperlipidemia, and obesity, were also retrieved for further evaluation. In total, 10,364 children and adolescents diagnosed with hypertension were identified. The prevalence of pediatric hypertension in Taiwan ranged from 0.19 to 0.38 per 1000 children and adolescents between 2000 and 2013. Essential hypertension was most commonly coded (90.6%), which was much more than secondary hypertension (14.3%). Children and adolescents with hypertension were often associated with DM, hyperlipidemia, and obesity, with the odds ratios as 14.05 (95% confidence interval (CI) 11.74-16.81, p < 0.001), 10.65 (95% CI 9.48-11.97, p < 0.001), and 19.08 (95% CI 15.65-23.26, p < 0.001), respectively. To improve lifelong cardiovascular health, our results emphasize the importance of early proper recognition and suitable management of hypertension, as well as metabolic syndrome-related diseases, among children and adolescents.

Unilateral generalized morphea: First case report in Taiwan

Generalised morphea (GM) is a subtype of localised scleroderma that usually manifests with bilateral involvement. Unilateral generalised morphea (UGM) is a rare variant of GM. This is a case report of a Taiwanese girl with UGM over the left side of her body. She presented with hyperpigmentation, tightness, and skin atrophy over the left extremities and trunk. Mild range of motion (ROM) limitation over the left knee was also noted. At the clinic, the patient was given oral prednisolone, oral methotrexate (MTX), and oral D-penicillamine. topical emollient and topical glucocorticoids were also given. The dose of oral prednisolone was tapered gradually. All symptoms were improved under the treatment and regular rehabilitation program. To date, there is very little evidence to form the basis for treatment recommendations. This case report provides a treatment option for UGM in the paediatric group without the use of intravenous methylprednisolone pulse therapy.

Characterization and activity of visible-light driven TiO2 photocatalyst doped with tungsten

This research aimed to expand the activity of TiO(2) down to the visible light region by modifying the sol-gel conditions and doping with tungsten. The optimum conditions for calcination temperature, acid type, and heating rate were 200°C, HNO(3), and 1°C/min, respectively. The undoped TiO(2) synthesized under these conditions could significantly absorb the visible light whereas the commercial Degussa P-25 could not. The absorptivity decreased sequentially as the wavelength increased from 400 to 700 nm. Within 6 h of 2-W blue-light illumination, 23% of 0.1 mM 2-chlorophenol was removed. The XRD result showed that the crystalline was anatase phase. The visible-light absorption property of the TiO(2) became even better when doped with tungsten. At the optimum W to TiO(2) ratio of 0.5%, the degradation of 0.1 mM 2-chlorophenol increased to 53% indicating a higher photocatalytic activity. Both crystalline and amorphous TiO(2) could exhibit the photocatalytic activity under the visible light region.

Catalytic action of goethite in the oxidation of 2-chlorophenols with hydrogen peroxide

The use of goethite and hydrogen peroxide was recently found to effectively oxidise organic compounds. This research was to investigate the effect of adsorption, pH, Fe2+ and Fe3+ on 2-CP oxidation. Results indicated that 2-CP can be decomposed with hydrogen peroxide catalysed by goethite and the oxidation rate increased with decreasing goethite particle size. The optimum oxidation rate was observed at the pH below 3.0. Addition of Fe2+ and Fe3+ can enhance the catalytic oxidation rate of 2-CP very efficiently. The main mechanism of goethite catalysing hydrogen peroxide to oxidise 2-CP may be due to the catalysis of ferrous ions and goethite surface.

Anti-myeloperoxidase antibodies enhance phagocytosis, IL-8 production, and glucose uptake of polymorphonuclear neutrophils rather than anti-proteinase 3 antibodies leading to activation-induced cell death of the neutrophils

Anti-neutrophil cytoplasmic antibodies (ANCA) not only are triggered by target protein myeloperoxidase (MPO) and proteinase 3 (PR3) of polymorphonuclear neutrophil (PMN) but also react with primed PMN to exert the inflammatory process in vasculitis syndrome. To clarify the crucial role of PMN in ANCA-associated vasculitis and the related mechanism, PMN was cultured with monoclonal antibody MPO-ANCA and PR3-ANCA to determine the function of phagocytosis, Interleukin- 8 (IL-8) production, glucose uptake, and TNF-related apoptosis induced ligand (TRAIL) production. The spontaneous membrane expression of MPO and PR3 on PMN could be significantly increased by lipopolysaccharide (LPS) and TNF-alpha, but not by IL-8 or GRO-alpha. The PMN-stimulating activity of ANCA was demonstrated by enhancing phagocytosis, IL-8 production, and glucose uptake that was more prominent by MPO-ANCA. The PMN stimulation by ANCA was not through protein kinase, H2O2, or superoxide anion radicals as their inhibitors exerted no effect on ANCA-mediated activation. On the other hand, ANCA also accelerated PMN apoptosis and increased TRAIL production. These results demonstrate that activation-induced cell death (AICD) mechanism could be initiated in PMN with existence of ANCA. In conclusion, MPO-ANCA is more potent in stimulating PMN than PR3-ANCA. ANCA-activated PMN is not only responsible for the amplified inflammatory process in blood vessel but also initiates immune circuit via triggered macrophage/monocyte by apoptotic PMN through the mechanism of AICD elicited by ANCA.

MBR/RO/ozone processes for TFT-LCD industrial wastewater treatment and recycling

This research is mainly to explore the treatment capacity for TFT-LCD industrial wastewater recycling by the processes combined with membrane bioreactor (MBR), reverse osmosis (RO) and ozone(O3). The organic wastewater from the TFT-LCD industry was selected as the target. MBR, RO and ozone plants were established for evaluation. An MBR plant consisted of a 2-stage anoxic/aerobic bioreactor and an immersed UF membrane unit was employed. The effluent of MBR was conducted into the RO system then into the ozone system. The RO system consisted of a spiral membrane in the vessel. One bubble column, 75 cm high and diameter 5 cm, were used as the ozonation reactor. On the bottom of ozonation reactor is a porous diffuser for releasing gas, with an aperture of 100 microm (0.1 cm). Over the whole experimental period, the MBR process achieved a satisfactory organic removal. The COD could be removed with an average of over 98.5%. For the TOC item, the average removal efficiency was 97.4%. The stable effluent quality and satisfactory removal performance were ensured by the efficient interception performance of an immersed UF membrane device incorporated with the biological reactor. Moreover, the MBR effluent did not contain any suspended solids and the SDI value was under 3. After the treatment of RO, excellent water quality was found. The water quality of permeate was under 5 mg/I, 2 mg/l and 50 micros/cm for COD, TOC and conductivity respectively. The treated water can be recycled and reused for the cooling tower make-up water or other purposes. After the treatment of ozone, the treated water quality was under 5 mg/l and 0.852 mg/l for COD and TOC respectively. The test results of MBR, MBR/RO and MBR/RO/ozone processes were compared as possible appropriate treatment technologies applied in TFT-LCD industrial wastewater reuse and recycling.

Treatment of non-biodegradable wastewater by electro-Fenton method

A novel electro-Fenton method, called the Fered-Fenton method, applying H2O2 and electrogenerated ferrous ions for treating organic-containing wastewater was investigated. By combining electrochemical reduction and chemical oxidation, the process can regenerate ferrous ions and remove organic compounds simultaneously in a batch reactor. Because the generation rate of ferrous ions is one of the key parameters in evaluating the oxidation efficiency of the reaction system, the initial current efficiencies (eta(i)) for iron (III) reduction are examined first. It shows that increasing initial ferric ion concentration can achieve high initial current efficiency. In addition, eta(i) decreased (ca. 20-100%) with increasing current density of cathode (ca. 40-199 A/m2). For illustration, the wastewater from chemical (i.e. electroless) nickel plating was treated in this investigation owing to its non-biodegradability and high organic concentration. The average pH, COD and Ni concentrations of this wastewater were about 5.0, 30,000 and 2,000 mg/L, respectively. Experimental results indicate that traditional Fenton method only removed 60% of COD when using 5,000 mg/L of ferrous ions. However, the COD removal efficiency was promoted after the electricity was introduced into the system (i.e. Fered-Fenton method). Moreover, Ni concentration was reduced from 2,080 to 0.3 mg/L, indicating that the removal efficiency was higher than 99.9%.

Preventing low birth weight: is prenatal care the answer?

OBJECTIVES

To review the evidence of effectiveness of prenatal care for preventing low birth weight (LBW).

METHODS

We reviewed original research, systematic reviews, meta-analyses and commentaries for evidence of effectiveness of the three core components of prenatal care--risk assessment, health promotion and medical and psychosocial interventions--for preventing the two constituents of LBW: preterm birth and intrauterine growth restriction (IUGR).

RESULTS

Clinical risk assessment will fail to identify the majority of pregnancies at risk for preterm delivery or IUGR. While biophysical and biochemical modalities appear promising, their cost-effectiveness has not been demonstrated, nor can their routine use be recommended in the absence of effective interventions. Smoking cessation programs appear to be modestly effective. There is insufficient evidence to conclude a benefit for nutrition interventions, work counseling or preterm birth education. Only antenatal corticosteroid therapy has demonstrated a clear benefit in the tertiary prevention of preterm delivery. Interventions for which there is insufficient evidence to conclude a benefit include bed rest, hydration, sedation, cerclage, progesterone supplementation, antibiotic treatment, tocolysis without concomitant use of corticosteroids, thyrotropin-releasing hormone, psychosocial support and home visitation. Additionally, there is a paucity of evidence supporting the effectiveness of prenatal interventions, such as low-dose aspirin, bed rest, maternal hyperoxygenation, plasma volume expansion and antenatal fetal assessment, in preventing IUGR or its associated morbidity and mortality.

CONCLUSIONS

Neither preterm birth nor IUGR can be effectively prevented by prenatal care in its present form. Preventing LBW will require reconceptualization of prenatal care as part of a longitudinally and contextually integrated strategy to promote optimal development of women's reproductive health not only during pregnancy, but over the life course.

Barriers and successful strategies to antiretroviral adherence among HIV-infected monolingual Spanish-speaking patients

Focus groups were conducted with HIV-infected, monolingual Spanish-speaking patients (N = 81) taking antiretrovirals in order to: (1) determine what barriers impede medication adherence; (2) determine what strategies facilitate adherence; and (3) investigate the health care provider-patient relationship and whether it impacts adherence. Both quantitative and qualitative information was gathered. Participants were prescribed an average of 11 pills per day (M = 11.4, SD = 7.0, range = 1-30). Only 32% of participants were consistently adherent when self-report of medication taking (yesterday, the day before yesterday, and last Saturday) was compared to prescribed regimen. The most frequently reported strategies were: learning more about the medications (77%), accepting the need to take them (75%) and refilling prescriptions early or on time (70%). Barriers most often reported were: feeling depressed or overwhelmed (21%), simply forgetting (19%) and sleeping through a dose (17%). From the qualitative data, four main issues emerged: patient characteristics, the health care professional-patient relationship, language and cultural barriers within the health care system, and the medication regimen. Among this Latino sample, having someone to live for was extremely important in terms of patient adherence. Language barriers were reported, and the use of translators was not always seen as a sufficient remedy. Differences between monolingual Spanish-speaking patients' and English-speaking patients' strategies and barriers are discussed.

Danggui shaoyao san improve colchichine-induced learning acquisition impairment in rats

AIM

To investigate the effects of the water extracts of Danggui Shaoyao San (DGSYS) in rats used the passive avoidance task.

METHODS

Impairment in learning acquisition in rats was induced by colchicines, and the level of superoxide dismutase in the brain and the effects of DGSYS on the locomotor activity and pain threshold induced by colchicines were detected.

RESULTS

DGSYS (0.1-1.0 g/kg) attenuated the impairment of learning acquisition induced by colchicine (15 microg) and DGSYS (0.5 and 1.0 g/kg) increased the level of SOD (141 +/- 3 and 135.4 +/- 2.0) in the brain. However, DGSYS (0.1 - 1.0 g/kg) did not affect the locomotor activity and pain threshold in the rats treated with colchicines.

CONCLUSION

DGSYS can improve the learning acquisition deficit induced by colchicine in rats. The action mechanism of DGSYS may be involved in the increase in the level of superoxide dismutase.

Intermediate inhibition in the heterogeneous UV-catalysis using a TiO2 suspension system

Langmuir-Hinshelwood (L-H) kinetic expression was used to develop a basic mathematical model, which could describe the inhibition of intermediates in the photocatalysis of 2-chlorophenol (2-CP) in a suspended TiO2 system. Results showed that the photocatalytic oxidation of 2-chlorophenol followed the L-H type behavior and the reaction by-products displayed an inhibiting effect on the degradation rate. The inhibition was estimated by comparing to observed and estimated half-lives. The higher the initial concentration of 2-chlorophenol, the higher the inhibition of photocatalytic reaction. The L-H kinetic has been modified slightly in this study to rationalize the contrast of inhibited behavior and to improve in favor of a surface reaction. The concentrations of 2-chlorophenol were investigated ranging from 7.78 x 10(-5) to 7.78 x 10(-4) mol l(-1). The degradation of 2-chlorophenol in this reaction condition approximates a first-order kinetics to near-complete degradation. Calculated kinetic profiles are in an excellent agreement with the experimental observation. The results of the theoretical analysis can be used to estimate reaction rates in different initial concentrations of target compound.

Role of cupric ions in the H2O2/UV oxidation of humic acids

The purpose of this study is to reveal the role of cupric ions as a natural water contaminant in the H2O2/UV oxidation of humic acids. Humic acids are naturally occurring organic matter and exhibit a strong tendency of complexation with some transition metal ions. Chlorination of humic acids causes potential health hazards due to formation of trihalomethane (THM). The removal of THM precursors has become an issue of public concern. The H2O2/UV process is capable of mineralizing humic acids due to formation of a strong oxidant, hydroxyl radicals, in reaction solution. Experiments were conducted in a re-circulated photoreactor. Different cupric concentrations (0-3.8 mg/l) and different pH values (4-9) were controlled to determine their effects on the degradation of humic acids, UV light absorbance at 254 nm, and H2O2. The presence of cupric ions inhibits humic mineralization and decreases the rate of destruction of humic acids which absorb UV light at 254 nm. On the other hand, the higher the cupric concentration, the lower the H2O2 decomposition rate. In the studied pH range, the minimum of total organic carbon (TOC) removal occurs at pH = 6 in the presence of 2.6 mg/l of cupric ions; both acidification (pH = 4) and alkaline condition (pH = 9) lead to a better removal of TOC. It is inferred from this study that the cupric-complexed form of humic acids is more refractory than the non-complexed one.

Catalytic decomposition of hydrogen peroxide and 2-chlorophenol with iron oxides

The aim of this study was to examine the catalyzed decomposition of hydrogen peroxide and 2-chlorophenol (2-CP) in the presence of iron oxides. Granular ferrihydrite, goethite, and hematite were selected as catalysts in this study. 2-CP was used as the model compound because it is a typical toxic compound and has not been investigated in the catalytic decomposition by iron oxides. The catalytic activity for hydrogen peroxide decomposition followed the sequence: granular ferrihydrite > goethite > hematite. However, hematite exhibited the highest activity in catalyzing 2-CP oxidation. The oxidation efficiency of 2-CP corresponded with the inverse sequence of specific area and pHpzc of the iron oxides. The catalytic activity of granular ferrihydrite was affected significantly by the mixing speed and particle size for its large value of Thiele modulus (phi) and Damkohler number (Da). The strong diffusion resistance for granular ferrihydrite was attributed either to its microporous structure or to the formation of oxygen in the pores of the iron oxide leading to the unexpected catalytic activity of granular ferrihydrite to hydrogen peroxide and 2-CP.

Use of contraceptive methods among homeless women for protection against unwanted pregnancies and sexually transmitted diseases: prior use and willingness to use in the future

Lifetime contraceptive use as reported by a representative sample of 764 homeless women in Los Angeles was examined overall and for different age and ethnic subgroups and contrasted with expressed willingness to use specific methods. Over 80% of the women reported condom use. However, less than 5% had ever used female condoms, although 38% of the overall sample and 73% of the teenagers said they were willing to try them. Similar gaps between reported use and endorsement were found for other particular methods. Native Americans had relatively low use of virtually all contraceptive methods, and over 80% of African-Americans rejected implants. Our findings suggest that age-related factors and ethno-cultural perceptions may deter some homeless women from using contraception. In any case, gaps between realized use and willingness to use may represent missed opportunities to prevent the high rates of unintended pregnancies and sexually transmitted infections found among homeless women.

Provider encouragement of breast-feeding: evidence from a national survey

OBJECTIVE

To examine the influence of provider encouragement on breast-feeding among women of different social and ethnic backgrounds in the United States.

METHODS

A nationally representative sample of 2017 parents with children younger than 3 years was surveyed by telephone. The responses of the 1229 women interviewed were included in the analysis. Respondents were asked to recall whether their physicians or nurses had encouraged or discouraged them from breast-feeding. The effects of provider encouragement on breast-feeding initiation and duration were evaluated by multivariate logistic regression. The sample was then stratified to allow subset analyses by race and ethnicity, education, income class, age group, and marital status.

RESULTS

More than one-third (34.4%) of respondents did not initiate breast-feeding. Three-fourths (73.2%) of women reported having been encouraged by their physicians or nurses to breast-feed; 74.6% of women who were encouraged initiated breast-feeding, compared with only 43.2% of those who were not encouraged (P < 0.001). Women who were encouraged to breast-feed were more than four times (relative risk 4.39; 95% confidence interval 2.96, 6.49) as likely to initiate breast-feeding as women who did not receive encouragement. The influence of provider encouragement was significant across all strata of the sample. In populations traditionally less likely to breast-feed, provider encouragement significantly increased breast-feeding initiation, by more than threefold among low-income, young, and less-educated women; by nearly fivefold among black women; and by nearly 11-fold among single women.

CONCLUSION

Provider encouragement significantly increases breast-feeding initiation among American women of all social and ethnic backgrounds.

Influence of pH on the dewatering of activated sludge by Fenton's reagent

The specific filtration resistance, moisture, and SVI were used to evaluate the influence of pH on the filtration and dewatering efficiencies when applying Fenton's reagent to treat the excess sludge. The excess sludge used in this study was obtained from the wastewater treatment plant of An-Ping Industrial Park in Tainan, Taiwan. Results show that initial pH has no significant effect on the filtration efficiency of sludge by using the Fenton (Fe2+/H2O2) system as the treatment process. However, the reduction of specific resistance by Fenton-like (Fe3+/H2O2) process decreased suddenly to a level similar to that obtained from the control experiment at initial pH > 4.5. For the moisture of cake sludge, both Fenton and Fenton-like systems have the same tendency; the moisture of cake sludge increased slightly with increasing the initial pH. The SVI values for Fenton process decreased with increasing the initial pH, but the opposite result was obtained from the Fenton-like and control system; higher pH was not favorable for the sludge settling.

Resistance to apoptosis in HIV-infected CD4+ T lymphocytes is mediated by macrophages: role for Nef and immune activation in viral persistence

Apoptosis or programmed cell death may play a critical role in AIDS pathogenesis through depletion of both CD4(+) and CD8(+) T lymphocytes. Using a reporter virus, a recombinant HIV infectious clone expressing the green fluorescent protein (GFP), apoptosis was measured in productively infected CD4(+) T lymphocytes, in the presence and absence of autologous macrophages. The presence of macrophages in the culture increased the frequency of nonapoptotic GFP-positive productively infected CD4(+) T lymphocytes. The appearance of nonapoptotic productively infected CD4(+) T lymphocytes in the culture required intercellular contacts between macrophages and PBLs and the expression of the HIV Nef protein. The presence of macrophages did not reduce apoptosis when CD4(+) T lymphocytes were infected with a GFP-tagged virus deleted for the nef gene. TNF-alpha (TNF) expressed on the surface of macrophages prevented apoptosis in nef-expressing, productively infected CD4(+) T lymphocytes. Similarly, following TNF stimulation, apoptosis was diminished in Jurkat T cells transfected with a nef-expressing plasmid. TNF stimulation of nef-expressing Jurkat T cells resulted in NF-kappaB hyperactivation, which has been shown to deliver anti-apoptotic signals. Our results indicate that intercellular contacts with macrophages increase the rate of productively infected nonapoptotic CD4(+) T lymphocytes. The survival of productively infected CD4(+) T lymphocytes requires Nef expression as well as activation by TNF expressed on the surface of macrophages and might participate in the formation and maintenance of viral reservoirs in HIV-infected persons.

Severity of homelessness and adverse birth outcomes

Predictors and the prevalence of adverse birth outcomes among 237 homeless women interviewed at 78 shelters and meal programs in Los Angeles in 1997 were assessed. It was hypothesized that they would report worse outcomes than national norms, that African Americans would report the worst outcomes because of their greater risk in the general population, and that homelessness severity would independently predict poorer outcomes beyond its association with other adverse conditions. Other predictors included reproductive history, behavioral and health-related variables, psychological trauma and distress, ethnicity, and income. African Americans and Hispanics reported worse outcomes than are found nationally, and African Americans reported the worst outcomes. In a predictive structural equation model, severity of homelessness significantly predicted low birth weight and preterm births beyond its relationship with prenatal care and other risk factors.

Outcomes of extremely low-birth-weight infants between 500 and 750 g

OBJECTIVE

The purpose of this study was to describe morbidity, mortality, and developmental outcomes among extremely low-birth-weight infants (500-750 g).

STUDY DESIGN

This retrospective cohort study included 167 live-born infants born at Long Beach Memorial Medical Center between January 1990 and December 1995.

RESULTS

Mortality rates were 86% among infants <600 g and 44% among those > or =600 g, and the rate decreased with increasing gestational age. The absence of chorioamnionitis (P =.01) and the use of antepartum corticosteroids (P <.0001) or neonatal surfactant (P =.0001) were associated with survival. Sixty-four percent of studied infants had respiratory distress syndrome, and 17% had grade III or IV intraventricular hemorrhage. Among the 63 survivors 57% were tested at 30 months of corrected age with the Bayley Scales of Infant Development. Mild or significant delays were seen on the mental development index in 68% of these cases and on the psychomotor development index in 58% of cases.

CONCLUSION

Morbidity and mortality rates and the rate of developmental delay among infants with birth weights between 500 and 750 g were significant.

Digit effects produced by prenatal exposure to antiepileptic drugs

The hypothesis tested was that digit anomalies among individuals exposed in utero to antiepileptic drugs (AED) are best identified by a systematic search, including radiographs and dermatoglyphics, rather than relying only on visual inspection. A systematic search was made for five types of digit abnormalities in 46 AED-exposed individuals ages 5-29 years in comparison with controls: visible anomalies, size of fingernails, dermal ridge patterns, length of metacarpals and phalanges, and qualitative changes in the distal phalanges. Among the AED-exposed, nail size was not decreased. However, there was a 10.8% frequency of digit anomalies, a 12% frequency of three or more arch patterns, and significant shortening and qualitative changes in the distal phalanges, all of which are consistent with the fetal effects of AED. Among the 42 individuals who underwent all evaluations, 14.3% had two or more of these abnormalities, most of which would not be identified by clinical inspection. This frequency is much higher in these AED-exposed individuals than in the general population. Radiographs in 13 individuals over a period of several years showed that the changes in the phalanges and metacarpals persisted.

Oxidation of chlorophenols with hydrogen peroxide in the presence of goethite

The use of goethite (alpha-FeOOH) and hydrogen peroxide was recently found that they could effectively oxidize organic compounds. The study was to investigate the effect of goethite particle size, goethite concentration, Fe2+ and Fe3+ on the 2-chlorophenol oxidation. Results indicated that 2-chlorophenol can be decomposed with hydrogen peroxide catalyzed by goethite and the oxidation rate increased with decreasing goethite particle size. 2-Chlorophenol degradation was almost retarded with 0.8 g/l of goethite because ferrous ions could not be produced at this condition. Addition of Fe2+ and Fe3+ can enhance the catalytic oxidation rate of 2-chlorophenol very efficiently. In conclusion, the main mechanism of goethite catalyzing hydrogen peroxide to oxidize 2-chlorophenol may be due to the catalysis of ferrous ions and goethite surface.

Elimination of public funding of prenatal care for undocumented immigrants in California: a cost/benefit analysis

OBJECTIVE

We compared the perinatal outcomes and costs of undocumented women with and without prenatal care and inferred the impact of denial of prenatal benefits to undocumented immigrants in California.

STUDY DESIGN

We retrospectively reviewed the delivery records of a cohort of 970 undocumented immigrants. The effects of prenatal care on low birth weight and prematurity were evaluated by means of logistic regression. The difference in the costs of postnatal care between neonates with and without prenatal care was compared with the cost of prenatal care. This ratio was extrapolated to calculate the net cost to the state. Long-term morbidity costs were also considered.

RESULTS

Nearly 10% of undocumented women had no prenatal care. These women were nearly 4 times as likely to be delivered of low birth weight infants (relative risk, 3.8; 95% confidence interval, 2.03-7.05) and >7 times as likely to be delivered of premature infants (relative risk, 7.4; 95% confidence interval, 4.35-12.59) as were undocumented women who had prenatal care. The cost of postnatal care for a neonate without prenatal care was $2341 more initially and $3247 more when incremental long-term morbidity cost was added than that for a neonate with prenatal care. For every dollar cut from prenatal care we expect an increase of $3. 33 in the cost of postnatal care and $4.63 in incremental long-term cost. Elimination of publicly funded prenatal care for undocumented women could save the state $58 million in direct prenatal care costs but could cost taxpayers as much as $194 million more in postnatal care, resulting in a net cost of $136 million initially and $211 million in long-term costs.

CONCLUSIONS

Elimination of public funding of prenatal care for undocumented immigrants in California could substantially increase low birth weight, prematurity, and postnatal costs.

Oxidation of dichlorvos with hydrogen peroxide using ferrous ion as catalyst

This study examines how Fenton's reagent (Fe2+ and H2O2) decomposed dichlorvos insecticide. Results showed that dichlorvos decomposed in a two-stage reaction. The first stage is a Fe2+/H2O2 reaction in which dichlorvos swiftly decomposed. In the second stage, dichlorvos decomposed somewhat less rapidly, and it is a Fe3+/H2O2 reaction. The detection of ferrous ions also supports the theory of the two-stage reaction for the dichlorvos oxidation with Fenton's reagent. The dissolved oxygen of the solution decreased rapidly in the first stage reaction, but it slowly increased in the second stage with a zero-order kinetics. The Fenton system decomposed dichlorvos most rapidly when the initial pH in the solution is 3-4. In addition, increasing the concentration of hydrogen peroxide or ferrous ions can enhance the decomposition of dichlorvos. Consequently, the relationship of rate constant (kobs), [H2O2] and [Fe2+] at initial pH 3 is determined as kobs = 2.67 x 10(4)[H2O2]0.7[Fe2+]1.2.

Effect of adsorbents coated with titanium dioxide on the photocatalytic degradation of propoxur

Photocatalytic oxidation of pesticides in aqueous media irradiated by UV light is a rapidly growing field of research. Therefore, the treatment technology for degradation of propoxur (an insecticide) using titanium dioxide coated on the supports such as activated carbon, zeolite, brick, quartz and glass beads, was performed in this research. Results show that GAC/TiO2 is the best complexing agent for oxidizing propoxur because of its adsorption properities. The others follow the sequence: plain TiO2 > glass beads > zeolite > brick > quartz. The degradation rate of propoxur with plain TiO2 is higher than that with TiO2/GAC complexing agent. But the mineralization rate of propoxur with plain TiO2 is lower than that with TiO2/GAC complexing agent. However, it can be concluded that using GAC as the support can improve the photocatalytic efficiency.

Effects of Jen-San-Yaung-Jung-Tang on scopolamine-induced amnesia in rats

The effect of Jen-San-Yaung-Jung-Tang (YJT) on scopolamine (SCOP)-induced amnesia was investigated in a step-through passive avoidance task in rats. It was observed that YJT (0.5 and 1.0 g/kg) significantly improved SCOP-induced amnesia and did not change the horizontal activity and pain threshold. YJT at 0.5 and 1.0 g/kg also did not change SCOP-treated horizontal activity and pain threshold. Furthermore, the antiamnesic effect of YJT at 1.0 g/kg on the SCOP-induced amnesia was augmented by physostigmine, but was not altered by neostigmine or scopolamine N-methylbromide. These results suggest that the antiamnesic effect of YJT could only be related to the memory-related process, and to an increase in central cholinergic neuronal activity.

Clinical and histologic trends of melanoma

BACKGROUND

Several changing clinical and histopathologic melanoma trends occurred from the 1950s to the 1980s.

OBJECTIVE

The purpose of this study was to evaluate melanoma trends during the past decade and to compare present trends to those documented during the past four decades.

METHODS

Sex, age at diagnosis, location, tumor thickness, stage, and histologic subtypes were evaluated from 1984 to 1995 and compared with trends during the past four decades.

RESULTS

Most changing trends from the past four decades have slowed or stabilized during the past decade.

CONCLUSION

Complete reporting of all melanomas to central tumor registries is necessary to accurately analyze present and future melanoma trends. Ongoing and new prevention and control strategies beginning at birth may be necessary to continue the positive efforts to curtail the melanoma epidemic.

Studies on the sedative effect of Cistanche deserticola

In this study, we investigated the sedative effect of Cistanche deserticola Ma. (CD) on hexobarbital-induced sleeping time in mice and spontaneous motor activity by using automated activity meter in rats. It was found that crude extract of CD could prolong the hexobarbital-induced sleeping time and reduce spontaneous motor activity, including horizontal activity, ambulatory time and total distance. Then the water fraction of CD extract could prolong the hexobarbital-induced sleeping time and reduce the spontaneous motor activity more than that of the other fraction of CD extract in rats. These results suggest that CD ethanol extract and its water fraction possessed the sedative effect.

Age-related enhancement of 5-lipoxygenase metabolic capacity in cattle alveolar macrophages

Arachidonic acid (AA) metabolism was assessed in cultured alveolar macrophages (AM) obtained from newborn (9- and 23-day-old) and adult (2- and 6-yr-old) cattle. The AM were prelabeled in [3H]AA-containing medium and, thereafter, stimulated with either A-23187 or zymosan. The released radiolabeled AA metabolites were measured by high-performance liquid chromatography with on-line radiodetection. The results showed that, among different-aged cattle, the synthesis of total 5-lipoxygenase (5-LO) metabolites [leukotrienes (LT) B4, LTC4, LTD4, and 5-hydroxyeicosatetraenoic acid (5-HETE)] increased with age in spite of similar levels of phospholipase-catalyzed AA release. In response to A-23187 and zymosan, 5-LO metabolic capacity of adult cattle AM was approximately 4- and approximately 10-fold that of 9-day-old cattle AM, respectively. As 5-LO metabolic capacity increased, the release of prostaglandins and thromboxane tended to decrease. Immunoblot analysis showed that the steady-state expression of 5-LO and 5-lipoxygenase-activating protein (FLAP) also increased in an age-dependent manner. In newborn calves, AM do not produce great amounts of LTB4; this factor might contribute to insufficient polymorphonuclear leukocyte recruitment into the alveolar space and the high susceptibility to neonatal lung infection.

Production of chitinase by Pseudomonas aeruginosa K-187 using shrimp and crab shell powder as a carbon source

Shrimp and crab shell powder prepared by treating shrimp and crab processing waste with boiling and crashing was used as a substrate for isolating alkali-tolerant chitinolytic microorganisms. Strain K-187 appeared to be the chitinase-producing strain with the most potential. The organism was identified as a strain of Pseudomonas aeruginosa. Maximum chitinase activity was obtained when the strain was grown aerobically in a medium consisting of 3.0% shrimp and crab shell powder, 0.1% CMC, 0.1% (NH4)2SO4, 0.1% K2HPO4, 0.1% MgSO4.D7H2O and 0.1% ZnSO4 (pH 9), at 45 degrees C after 3 days. The optimum pH and temperature of the enzyme reaction were 7 and 40 degrees C, respectively. The chitinase was stable at pH from 5 to 10 and was stable under 60 degrees C.

Catecholamine affects acetylcholine release in trachea: alpha 2-mediated inhibition and beta 2-mediated augmentation

We investigated the effects of catecholamines on acetylcholine (ACh) release from equine airway parasympathetic nerves. Trachealis strips were suspended in 2-ml tissue baths with Krebs-Henseleit solution containing atropine (10(-7) M), neostigmine (10(-6) M), and guanethidine (10(-5) M). Electrical field stimulation (20 V, 0.5 ms, 0.5 Hz, for 15 min) was applied, and ACh was measured by high-performance liquid chromatography with electrochemical detection. Epinephrine (Epi) and norepinephrine (NE) inhibited ACh release in a concentration-dependent manner. Inhibition was attenuated by the alpha 2-adrenoceptor antagonist idazoxan (10(-6) M) but not by the alpha 1-antagonist prazosin (10(-6) M). After alpha 2-blockade with idazoxan (10(-5) to 10(-4) M), Epi but not NE augmented ACh release. Isoproterenol (10(-7) to 10(-5) M) increased ACh release, an effect that was reversed by the beta 2-adrenoceptor antagonist ICI-118,551 (10(-5) M) but not by the beta 1-adrenoceptor antagonist atenolol (10(-5) M). Our results indicate that horse airway cholinergic nerves are modulated by both alpha 2-inhibitory and beta 2-excitatory adrenoceptors, with the former being predominant.

Why it was hard for me to learn compassion as a third-year medical student

Ms. B. was a 70-year-old woman who presented with a chief complaint of “my belly got puffy.” She noted that her waistband got progressively tighter as her abdomen swelled up on the month prior to her admission. Although not painful, the swelling caused considerable discomfort and anorexia.

Ms. B. had come to the university hospital by referral from her primary care doctor. She was my first patient on my junior clerkship in internal medicine, a specialty I was particularly interested in going into. It is a rare opportunity for a medical student to pick up a mystery case. Ms. B. had come to us without a diagnosis.

Measurement of circulating blood volume in vivo after trauma-hemorrhage and hemodilution

Although cardiac output (CO) and other hemodynamic variables are used to assess the adequacy of fluid resuscitation after hemorrhage, it is not known whether there is any correlation between restoration of CO and circulating blood volume (CBV). To determine this, rats underwent a midline laparotomy (i.e., trauma induced) and were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of maximum bleedout volume was returned in the form of Ringer lactate (RL). The animals were then resuscitated with four or five times the volume of maximum bleedout in the form of RL. CO and hepatocellular function were measured using an in vivo hemoreflectometer. CBV was monitored by using in vivo indocyanine green clearance. A good correlation between the values of blood volume obtained by this method and the 125I-albumin method indicates that the indocyanine green method is also a reliable technique for measuring CBV. Results indicate that resuscitation after hemorrhage improved the decreased CBV but did not restore it to control levels despite the fact that CO was restored and central venous pressure was more than doubled. A good correlation between depressed CBV and hepatocellular dysfunction was also observed under such conditions. Thus measurement of CBV appears to be useful for evaluating the adequacy of fluid resuscitation after trauma-hemorrhage and hemodilution.

Pharmacological evaluation of 2-amino-6(7)- and 9-amino-6-trifluoromethylbenzonorbornenes, the conformationally rigid analogues of norfenfluramine in mice

1. The possible role of conformational requirements which fenfluramine and norfenfluramine must satisfy to elicit its observed pharmacological activities was investigated in mice with the use of four conformationally-rigid norfenfluramine analogues. 2. In this study, both the syn-9-amino and endo-2-amino isomers, which structurally resemble the gauche conformation of norfenfluramine, were found to have little or no effect on spontaneous locomotor activity. 3. On the other hand, the isomers (i.e. the anti-9-amino and exo-2-amino isomers) that mimic the anti conformation of norfenfluramine were capable of causing a decrease in spontaneous motor activity similar to that of norfenfluramine. 4. The analgesic activities of these rigid analogues were also assessed and all of the isomers were found to be weakly analgesic. 5. Only the exo-2-amino isomer exhibited analgesic potency similar to that of fenfluramine. Furthermore all of these compounds were capable of enhancing the analgesic activity of morphine.

Structure modification and biological activity of some griseofulvin derivatives

Griseofulvin is an orally acting anti-fungal antibiotic with very limited water solubility. Five chemical modifications were made on the griseofulvin structure in order to evaluate these changes on the antifungal and water solubility properties. Antifungal activity was measured against Tricophyton mentagrophytes, T. rubrum, T. terrestre, and Microsporum canis. The oxime of griseofulvin was the most potent of the five compounds tested, but it was only of equal or less potency than griseofulvin. The somewhat increased water solubility of some of these compounds was offset by the lower anti-fungal potency of the structural modification.

The use of the polymerase chain reaction to identify porcine isolates of Trichinella

A method was developed to identify domestic isolates of Trichinella using the polymerase chain reaction. Oligonucleotide primers, based on the repetitive DNA sequence (pPRA) from the P1 isolate of Trichinella, were used to amplify genomic DNA from 13 domestic isolates and tested against sylvatic isolates of Trichinella. Pattern differences were observed among domestic isolates, indicating divergence of this repetitive sequence. The primers were specific for domestic Trichinella as no amplification was detected for sylvatic isolates or Trichinella pseudospiralis. It was possible to identify an isolate from a single larva following digestion or in situ in muscle tissue.

Inhibition of cholesterol side-chain cleavage. Part 5. Synthesis of 22-(p-chlorophenyl) cholesterol analogues

Three 22-(p-chloroaryl) analogues of cholesterol (6a-c) were synthesized and evaluated as potential inhibitors of the adrenal cholesterol side-chain cleavage enzyme, in comparison with the known 20-aryl analogue, 20-(p-chlorophenyl)-5-prenen-3 beta,20-diol (2b). All were potent inhibitors. An oxygen at C-22 (analogues 6a and 6b) enhanced the strong binding to the enzyme. Two compounds (6b and 6c) are potential substrates of the enzyme. Possible pharmaceutical uses for these compounds and their derivatives are discussed.

Preparation and use of double-labelled enterobactin

Double-labelled 3H/14C-enterobactin was isolated from bacterial cultures, and evaluated as a potential tool for studying the mammalian metabolism of this iron chelator. Microbial yields were low, but adequate, with a final 3H/14C ratio of 2.95 to 1. Studies conducted with mice indicated that considerable metabolism and rapid elimination of an intraperitoneally injected sample had occurred in 24 hours.

Genes for immunodominant protein antigens are highly homologous in Mycobacterium tuberculosis, Mycobacterium africanum, and the vaccine strain Mycobacterium bovis BCG

The relatedness of immunodominant protein antigens in Mycobacterium tuberculosis, M. africanum, and M. bovis BCG was investigated by comparing the genes that encode major protein antigens in M. tuberculosis with their counterparts in the other two mycobacteria. Genes encoding homologs of M. tuberculosis major protein antigens were isolated from M. africanum and M. bovis BCG by constructing lambda gt11 recombinant DNA expression libraries and screening them with murine monoclonal antibodies and DNA probes. The antibodies were directed against four major protein antigens of M. tuberculosis with molecular masses of 71, 65, 19, and 14 kilodaltons. The isolated M. africanum and M. bovis BCG DNA clones were mapped with restriction endonucleases, and the maps of the mycobacterial genes were confirmed by Southern analysis of mycobacterial genomic DNA. The restriction maps of DNA containing the four genes in M. tuberculosis, M. africanum, and M. bovis BCG are identical, indicating that the immunodominant proteins that they encode are highly homologous in the three mycobacteria. Thus, the immunity against tuberculosis engendered by M. bovis BCG vaccination could be provided, at least in part, by the immune response to these homologous antigens.

Molecular modification of anticholinergics as probes for muscarinic receptors. 3. Conformationally restricted analogues of benactyzine

The synthesis and pharmacological evaluation of conformationally restricted analogues of certain anticholinergic agents is a powerful method for probing the topography of the muscarinic receptor. In the present study, clues as to the binding conformation of structurally flexible anticholinergics are provided by approximating certain conformations of benactyzine by synthetic analogues 1-6, which are structurally locked into desired conformations. The pharmacological activity of each analogue is an indication of how well particular conformational models are accommodated by the receptor. The conformation of benactyzine in which an intramolecular hydrogen bond may exist between the hydroxyl group and the carbonyl oxygen of the ester group (conformation I) is approximated by the synthetic analogue 2,2-diphenyl-3-tetrahydrofuranyl (diethylamino)ethyl ether (1) and related analogues. Pharmacological evaluation using dose-response experiments on isolated rat ileum tissue demonstrated that these compounds noncompetitively inhibited acetylcholine-induced ileum contractions. Restriction of the conformational freedom of the amino side chain of 1 by synthesis of the hexahydro[3,4-b]furan derivative 3 provided a weak but competitive inhibitor at low concentration. The conformation of benactyzine in which an intramolecular hydrogen bond may exist between the hydroxyl group and the ether oxygen of the ester group (conformation II) is approximated by 2,2-diphenyl-4-[2-(diethylamino)ethyl]-3-tetrahydrofuranone (4). Pharmacological studies showed that this compound competitively inhibited acetylcholine-induced ileum contractions. These experiments provide evidence that receptor-bound conformation II for benactyzine is preferred over conformation I in providing competitive binding with the muscarinic receptor.

Molecular modification of anticholinergics as probes for muscarinic receptors. 1. Amino esters of alpha-substituted phenylacetic acid and related analogues

Two series of compounds having the general structure of C6H5CRR'COOCH2CH2NEt2 were synthesized and examined for their antispasmodic activities. These compounds were selected as structural probes for exploring the nature of muscarinic cholinergic receptor binding sites that interact with atropine-like anticholinergics. These studies indicate a rather strict size limitation for the hydrophobic region of the receptor and suggest intramolecular hydrogen bonding as a possible means to explain the observed stereoselectivity.

Molecular modification of anticholinergics as probes for muscarinic receptors. 2. Amino esters of alpha-methyltropic acid

As a continuation of our goals to study molecular probes for muscarinic cholinergic receptors, a series of 3-substituted 2-methyl-2-phenylpropanoates with the general structure of C6H5C(CH2X)(CH3)COOCH2CH2NEt2 where X = OH, OTs, F, Cl, Br, I, and OAc were prepared and their antispasmodic activities examined on isolated rat ileum preparations. Structure-activity relationship studies with these compounds provide further evidence suggesting that binding of an aromatic moiety in a specific location within the hydrophobic region of the receptor is important for anticholinergic potency. A nucleophilic displacement of chloride by "naked" fluoride under mild conditions is also reported.

Pharmacological properties of two amino esters of diphenylpropanoic acid

N, N-Diethylaminoethyl ester and 3-quinuclidinyl ester of 2, 2-diphenylpropanoic acid (compound 1 and 2, respectively) were prepared and pharmacologically evaluated in vitro and in the intact animal. Both compounds attenuated the effects of increasing doses of ACh in the isolated rat ileum (pA2 = 8.40 and 8.55, respectively). These effects were comparable to that of atropine (pA2 = 8.73). The duration of methacholine-induced salivation in male Swiss-Webster mice was significantly decreased by compound 2 but not by compound 1. Cardiorespiratory studies in adult male Sprague-Dawley rats revealed that both compounds shifted the dose-response curves to methacholine in terms of arterial blood pressure, heart rate and respiration upwards; indicative of cholinergic blockade. The observed pharmacological differences between the two compounds may be attributed to apparent in vivo hydrolysis of compound 1 by esterases.

The effects of stereoisomers of 2-amino-6(7)- and 9-amino-6-trifluoromethylbenzonorbornenes on food intake, brain serotonin concentration, and monoamine oxidase activity

To evaluate the importance of the conformation of fenfluramine in eliciting its various central nervous system effects, the isomers of 2-amino-6(7)- and 9-amino-6-trifluoromethylbenzonorbornene were employed as conformationally defined analogs of norfenfluramine. In this series of isomeric amines, the exo-2 and anti-9 isomers resemble the fully extended conformation of fenfluramine, whereas the endo-2 and syn-9 isomers resemble the folded conformation. The exo-2 and anti-9 isomers were equi-effective in reducing food intake in the rat, but were approximately seven times less potent than fenfluramine. The endo-2 and syn-9 isomers had no effect on food intake up to a dose of 40 mg/kg. All of the isomers were as effective as amphetamine in inhibiting brain monamine oxidase type B. These isomers also inhibited monoamine oxidase type A to the same extent as type B, but were significantly less potent than amphetamine in inhibiting this form of the enzyme. The effects at anorectic doses on brain serotonin (5-HT) concentration were also studied. Although fenfluramine decreased brain 5-HT concentration, the exo-2, syn-9 and anti-9 isomers had no significant effect. The endo-2 isomers caused an 11% decrease in 5-HT concentration, but this effect was observed at higher doses of the compound. The data suggest that the fully extended conformation of fenfluramine is preferred over the folded conformation for eliciting its anorectic activity. However, no conclusion can be made for the conformational requirements for the other biological responses investigated in this study.