Generative Adversarial Network-Enhanced Ultra-Low-Dose [18F]-PI-2620 τ PET/MRI in Aging and Neurodegenerative Populations

BACKGROUND AND PURPOSE

With the utility of hybrid τ PET/MR imaging in the screening, diagnosis, and follow-up of individuals with neurodegenerative diseases, we investigated whether deep learning techniques can be used in enhancing ultra-low-dose [18F]-PI-2620 τ PET/MR images to produce diagnostic-quality images.

MATERIALS AND METHODS

Forty-four healthy aging participants and patients with neurodegenerative diseases were recruited for this study, and [18F]-PI-2620 τ PET/MR data were simultaneously acquired. A generative adversarial network was trained to enhance ultra-low-dose τ images, which were reconstructed from a random sampling of 1/20 (approximately 5% of original count level) of the original full-dose data. MR images were also used as additional input channels. Region-based analyses as well as a reader study were conducted to assess the image quality of the enhanced images compared with their full-dose counterparts.

RESULTS

The enhanced ultra-low-dose τ images showed apparent noise reduction compared with the ultra-low-dose images. The regional standard uptake value ratios showed that while, in general, there is an underestimation for both image types, especially in regions with higher uptake, when focusing on the healthy-but-amyloid-positive population (with relatively lower τ uptake), this bias was reduced in the enhanced ultra-low-dose images. The radiotracer uptake patterns in the enhanced images were read accurately compared with their full-dose counterparts.

CONCLUSIONS

The clinical readings of deep learning-enhanced ultra-low-dose τ PET images were consistent with those performed with full-dose imaging, suggesting the possibility of reducing the dose and enabling more frequent examinations for dementia monitoring.

[Cochleo-vestibular lesions and prognosis in patients with profound sudden sensorineural hearing loss: a comparative analysis]

Objective: To investigate the characteristics of cochleo-vestibular dysfunction in patients with profound sudden deafness, and the prognosis of inner ear hemorrhage. Methods: From January 2017 to December 2018, 92 inpatients with profound sudden sensorineural hearing loss were enrolled in the Department of Otorhinolaryngology, First Affiliated Hospital of Sun Yat-sen University. Our studied patients included 47 males and 45 females, aged 20-78 (39.3±6.1) years. According to the results of inner ear magnetic resonance imaging (MRI), the patients were divided into two groups: inner ear hemorrhage group and non-inner ear hemorrhage group. The clinical features, vestibular tests and audiological examination results during follow up were compared between the two groups. SPSS 22.0 software was used for statistical analysis. Results: The inner ear hemorrhage group consisted of 32 cases (34.8%, 32/92), all of whom complained of vertigo (100%, 32/32). Simultaneous vertigo attack and hearing loss occurred in 78.1% of this group (24/32). Neither semicircular canals function, nor cervical vestibular evoked myogenic potential (c-VEMP), nor ocular vestibular evoked myogenic potential (o-VEMP) in the affected side was normal (100%, 32/32). The rates of benign paroxysmal positional vertigo (BPPV) and disequilibrium were 37.5% (12/32) and 25.0% (8/32) respectively. Hearing improved in 28.1% (9/32) two weeks after treatment, and became stable at one month's follow up. In 60 cases without inner ear hemorrhage, 58.3% of them (35/60) experienced vertigo, which occurred simultaneously with hearing loss in 21 patients (60%, 21/35). The abnormal rates of semicircular canals function, c-VEMP and o-VEMP were 71.6% (43/60), 78.3% (47/60) and 66.7% (40/60), respectively. The incidence of BPPV was 16.7% (10/60) and 8.3% (5/60) in cases with disequilibrium. Hearing improved in 58.3% (35/60) two week after treatment, and became stable at three months' follow up. Significant difference was found in either vertigo rate, or simultaneous vertigo/hearing loss rate, or abnormal c-VEMP/o-VEMP rates, or accompanying BPPV, or disequilibrium rates between the two groups (P<0.05 each). Moreover, we observed better hearing recovery in non-inner ear hemorrhage group in the two weeks, one month, three months and six months' follow up, when compared with those in inner ear hemorrhage groups (P<0.05 each). Conclusions: Inner ear hemorrhage is associated with more severe cochlea-vestibular lesion and poorer prognosis, in comparison to the non-inner ear hemorrhage,in patients with profound sudden sensorineural hearing loss.

[Clinical characteristics and etiological analysis of sudden deafness patients with vertigo]

Objective: To explore the possible causes and mechanisms of sudden deafness with vertigo. Methods: Between August 2016 and December 2017, 74 patients with sudden deafness and vertigo were hospitalized in the Department of Otolaryngology, First Affiliated Hospital of Sun Yat-sen University. Among them, 36 were male and 38 were female, aged 18-75 (40.5±6.5) years. According to the results of magnetic resonance imaging (MRI), the patients were divided into two groups: internal ear hemorrhage (IEH) and non-IEH (NIEH). The characteristics of deafness, vertigo, laboratory examination and follow-up results were compared between the two groups. Results: In IEH group, deafness and vertigo occurred simultaneously in 22 cases (84.6%), abnormalities of semicircular canal function, cervical vestibular evoked myogenic potential (C-VEMP), ocular vestibular evoked myogenic potential (O-VEMP) in 26 cases (100%) and benign paroxysmal positional vertigo (BPPV) in 10 cases (38.5%). The total effective rate was 19.2% (5/26) after 14 days of treatment, and 11 cases (42.3%) appeared disturbance after 180 days of treatment. The abnormal rate of lateral vestibular function, C-VEMP and O-VEMP was 69.2% (18/26), 53.8% (14/26) and 57.7% (15/26) respectively. The improvement of hearing threshold was (28.6±9.7) dB. In NIEH group, deafness and vertigo occurred simultaneously in 25 cases (52.1%). The abnormalities of semicircular canal function, C-VEMP and O-VEMP happened in 37 cases (77.1%), 34 cases (70.8%), 26 cases (54.2%), respectively, and 6 cases (12.5%) were of BPPV. The total effective rate was 52.1% (25/48) after 14 days of treatment. After 180 days of treatment, 8 cases (16.7%) were out of balance, and the abnormal rate of lateral vestibular function, C-VEMP and O-VEMP were 31.2% (15/48), 25.0% (12/48) and 20.8% (10/48) respectively. The improvement of hearing threshold was (42.5±10.3) dB. The incidence of stimulantous deafness and vertigo, vestibular dysfunction rate, BPPV incidence rate and the total effective rate after 14 days of treatment were significantly different between the two groups (all P<0.05). The vestibular and cochlear dysfunction in IEH group was more serious than that in NIEH group. After 180 days of treatment, the vestibular dysfunction rate, imbalance rate and improvement of hearing threshold in NIEH group were significantly higher than that in IEH group (all P<0.05). The recovery of vestibular and cochlear function in NIEH group was better than that in IEH group. Conclusions: Sudden deafness with vertigo can cause vestibular and cochlear dysfunction. Different etiologies may lead to different clinical features and prognosis. The vestibular and cochlear function damage caused by inner ear hemorrhage was more serious and the recovery effect was poor.

[Clinical study of inner ear hemorrhage-associated sudden deafness and vertigo]

Objective: To analyze the clinical features and possible pathogenesis of sudden deafenss and vertigo induced by inner ear hemorrhage. Methods: Clinical data of 30 patients with inner ear hemorrhage, from the first affiliated hospital of Sun Yat-sen university during Jan 2016 to May 2017, were retrospectively analyzed. Results: Vergito and profound deafness were seen in all patients. The duration of vertigo ranged from 24 hours to three days in 11 cases, three to 14 days in the remaining 19 cases. Simultaneous occurrence of vergito and deafenss were seen in 24 patients. Semicircular canal hypofunction and abnormal cervical vestibular evoked myogenic potentials(C-VEMP)/ocular vestibular evoked myogenic potentials(O-VEMP) were detected in all cases. Ten patients had benign paroxysmal positional vertigo(BPPV) simultaneously. Hearing recovered in 20% of the cohort posttreatment. Dizziness and balance disturbance disappeared 1 to 2 months after therapy in 16 cases. Long term (6 months) follow up revealed poor hearing outcome and vestibular rehabilitation. Conclusion: Vestibular vertigo and profound sensorineural hearing loss, with unsatisfactory clinical prognosis, constituted the characters of inner ear hemorrhage-associated sudden deafness.

Elevated Aminotransferases are Predictors of Hepatic Injury in Blunt Abdominal Trauma Patients

Objective

Computed tomography (CT) scan is currently the most commonly used tool for evaluating solid-organ injuries in trauma management. However, liberal use of CT scanning increases the risk of excess radiation exposure and toxicity from contrast material. Animal studies and clinical research on the paediatric population indicated that liver enzymes elevations were related to hepatic injury. The present study was undertaken to determine whether elevated liver enzymes were associated with the occurrence of hepatic injury in adult patients with blunt abdominal trauma.

Methods

This is a cross-sectional study from August 2003 to October 2006. All adult patients with blunt injury to abdomino-pelvic organs documented by CT or surgery who were admitted to Chi-Mei Medical Centre in the captioned period were included. The study population sorted to hepatic injury (HI) and no hepatic injury (NHI) groups according to the presence or absence of hepatic injury. Variables including liver enzymes were compared between the groups.

Results

Totally 419 patients were included, including 150 patients in the HI group and 269 patients in the NHI group. The HI group was younger and had a lower rate of laparotomy (36.3 years old vs 41.4 years old; 26% vs 42%, respectively). The mean levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the HI group were significantly higher than levels in the NHI group (439.6 IU/L vs 104.7 IU/L; 353.5 IU/L vs 76.6 IU/L, p<0.01). We define AST >200 IU/L or ALT level >125 IU/L as abnormal according to previous studies. The diagnostic characteristics of hepatic injury were 87.3% sensitivity, 80.3% specificity, 71.2% positive predictive value, and 91.9% negative predictive value.

Conclusion

In adults who have experienced blunt abdominal trauma, AST >200 U/L or of ALT >125 U/L are practical predictors of hepatic injury. Screening serum aminotransferases will have a role in detecting occult hepatic injury and may reduce the hazards of excessive CT scanning. (Hong Kong j.emerg.med. 2013;20:337-342)

Severe Hyperemesis Gravidarum Masking the Presentations of Hyperthyroidism

Hyperemesis gravidarum may present with weight loss and tachycardia secondary to dehydration. Its severity correlates with the level of the serum chorionic gonadotropin which can interfere with the assay of the thyroid stimulating hormone. Therefore, hyperemesis gravidarum are at times difficult to be distinguished from hyperthyroidism. Missing hyperthyroidism during pregnancy results not only in inappropriate maternal care, but adverse neonatal outcomes including low birth weight. The authors report a case of hyperemesis gravidarum complicated by the concurrence of hyperthyroidism. Goiter and refractory tachycardia are the useful clues to detect occult hyperthyroidism in patients with hyperemesis gravidarum.

Factors affecting the use of anti-amoebiasis protective measures among Taiwan immigrants returning to amoebiasis-endemic regions

OBJECTIVE

To investigate the predictors of use of anti-amoebiasis protective measures (AAPMs) among Taiwan immigrants returning to their country of origin, using the Health Belief Model (HBM) to guide the investigation.

DESIGN

Cross-sectional study.

METHODS

Between March and May 2011, all permanent immigrants originating from amoebiasis-endemic countries who received services at the immigrant service centres in Taipei or Tainan and who reported that they had returned to their country of origin within the past five years were enrolled in the study. A structured questionnaire containing questions on sociodemographic characteristics and items related to the constructs of the HBM was used as the data collection instrument.

RESULTS

Complete information was collected from 384 immigrants, with a response rate of 80% (384/480). The mean age of the subjects was 38.4 years (standard deviation 10.6 years). The majority (70%) of participants did not receive travel information through a pretravel consultation, and more than 17% reported that they did not use measures to prevent amoebiasis. Multiple regression analyses revealed that Chinese proficiency, pretravel consultation and lower barriers to using protective measures were significantly associated with the use of AAPMs during return trips to country of origin (R(2) = 0.45; F = 77.5; P < 0.001).

CONCLUSION

The HBM significantly predicted the use of AAPMs in this study. A high proportion of immigrants did not use appropriate AAPMs when they returned to their country of origin. Educational approaches should be targeted at immigrants originating from amoebiasis-endemic regions who return to their country of origin.

Conjunctival Inclusion Cyst

Conjunctival inclusion cysts are the most common cystic lesions of the conjunctiva and are either congenital or acquired; the latter are more prevalent. Some of the major factors that provoke the development of an acquired cyst are surgery, trauma, and chronic inflammation. Here, we report on a conjunctival inclusion cyst that developed following a case of untreated chronic conjunctivitis. To temporarily relieve the patient's symptoms a needle aspiration of the cyst was performed, and the patient was referred to an ophthalmologist for surgical excision of the cyst.

Cerebral “eThrombosis”: Cerebral Venous Sinus Thrombosis Associated with Prolonged Sitting in Front of a Computer

Venous thromboembolism caused by prolonged sitting during air travel has been recognised as economy-class syndrome for more than 30 years. Since 2003, the term “eThrombosis” has been proposed to describe the 21st Century variant of venous thromboembolism associated with immobilisation. We reported a case of cerebral venous sinus thrombosis presenting with severe headache after a prolonged period of sitting for over 12 hours in front of a computer for recreational purpose. We described this case as cerebral “eThrombosis”. Considering the widespread use of computers for many purposes including working, recreation and communications in the present digital era, we would like to put forward that prolonged immobilisation associated with computer use is a possible provoking risk factor of cerebral venous sinus thrombosis.

Severe Hyperemesis Gravidarum Masking the Presentations of Hyperthyroidism

Hyperemesis gravidarum may present with weight loss and tachycardia secondary to dehydration. Its severity correlates with the level of the serum chorionic gonadotropin which can interfere with the assay of the thyroid stimulating hormone. Therefore, hyperemesis gravidarum are at times difficult to be distinguished from hyperthyroidism. Missing hyperthyroidism during pregnancy results not only in inappropriate maternal care, but adverse neonatal outcomes including low birth weight. The authors report a case of hyperemesis gravidarum complicated by the concurrence of hyperthyroidism. Goiter and refractory tachycardia are the useful clues to detect occult hyperthyroidism in patients with hyperemesis gravidarum.

Capnography: An Accurate Method to Assess the Position of the Feeding Tube in a Porcine Model

Objective

To test the accuracy of capnography in the differential placement of feeding tubes into the trachea versus the oesophagus.

Method

Nineteen pigs were anesthetised, and feeding tubes were placed into their tracheas and oesophagi. A naïve examiner attached a capnography to the tube and evaluated the presence or absence of flow waveforms on the capnography. In the next step experiment, we gave 20 intentional oesophageal ventilations to the animals to create a distended stomach. The feeding tubes were reinserted, and examined by a naïve examiner by capnography.

Results

Capnography demonstrated continuous flow waveforms for the feeding tubes placed in the tracheas, but no waveforms were observed for those placed in the oesophagi. In the next step experiment, we found the same results.

Conclusion

Capnography can be used to accurately determine the placement of tracheal versus oesophageal feeding tubes based on the presence or absence of flow waveforms.

Photoluminescence Investigation of Surface Oxidation of C0.9Zn0.1 Te Detectors

The effect of surface oxidation of Cd1−xZnxTe (x = 0.1) detectors by chemical etching in hydrogen peroxide aqueous solution (H2O2) at different concentrations and etching times was investigated by low temperature photoluminescence (PL). The treatment resulted in better surface condition evidenced by the larger I(D0, X)/Idef intensity ratio and the narrower full width at half maximum of the main peak (D0, X). Peak shifts in the PL spectra associated with bound exciton lines and free to bound transition were also observed and attributed to the oxide layer. These surface effects were found to be dependent on H2O2 concentration and etching time. The significance of this surface oxidation on device passivation and the subsequent improvements in the detector performance are also discussed.

Intestinal alkaline phosphatase preserves the normal homeostasis of gut microbiota

BACKGROUND AND AIMS

The intestinal microbiota plays a critical role in maintaining human health; however, the mechanisms governing the normal homeostatic number and composition of these microbes are largely unknown. Previously it was shown that intestinal alkaline phosphatase (IAP), a small intestinal brush border enzyme, functions as a gut mucosal defence factor limiting the translocation of gut bacteria to mesenteric lymph nodes. In this study the role of IAP in the preservation of the normal homeostasis of the gut microbiota was investigated.

METHODS

Bacterial culture was performed in aerobic and anaerobic conditions to quantify the number of bacteria in the stools of wild-type (WT) and IAP knockout (IAP-KO) C57BL/6 mice. Terminal restriction fragment length polymorphism, phylogenetic analyses and quantitative real-time PCR of subphylum-specific bacterial 16S rRNA genes were used to determine the compositional profiles of microbiotas. Oral supplementation of calf IAP (cIAP) was used to determine its effects on the recovery of commensal gut microbiota after antibiotic treatment and also on the colonisation of pathogenic bacteria.

RESULTS

IAP-KO mice had dramatically fewer and also different types of aerobic and anaerobic microbes in their stools compared with WT mice. Oral supplementation of IAP favoured the growth of commensal bacteria, enhanced restoration of gut microbiota lost due to antibiotic treatment and inhibited the growth of a pathogenic bacterium (Salmonella typhimurium).

CONCLUSIONS

IAP is involved in the maintenance of normal gut microbial homeostasis and may have therapeutic potential against dysbiosis and pathogenic infections.

Comparison of photodegradative efficiencies and mechanisms of Victoria Blue R assisted by Nafion-coated and fluorinated TiO2 photocatalysts

The purposes of this research were to study the effects of two modified photocatalysts, Nafion-coated TiO(2) and fluorinated TiO(2), and photocatalytic degradation of Victoria Blue R in aqueous solution. Photocatalytic degradation of Victoria Blue R was accelerated by the modified photocatalysts. Bulk and surface characterizations of the resulting powders were carried out. Attachment of the anions to the TiO(2) surface using the Nafion-coated-TiO(2) possibly results in increased adsorption of the cationic dye, and the degradation rate is larger for the cationic dye. It was found that Victoria Blue R on the two illuminated TiO(2) surfaces underwent very different changes. To obtain a better understanding on the mechanistic details of this modified-TiO(2)-assisted photodegradation of the Victoria Blue R dye with UV irradiation, a large number of intermediates of the process were separated, identified, and characterized by a high-performance liquid chromatography-mass spectrometry technique. Several probable photodegradation pathways were proposed and discussed.

Impact of GB virus type C infection on mother-to-child HIV transmission in the Women and Infants Transmission Study Cohort

BACKGROUND

GB virus type C (GBV-C) viraemia is associated with a beneficial outcome in HIV-infected individuals in several though not all studies. GBV-C viraemia was examined in a matched case-control study of 133 HIV-infected pregnant women who transmitted HIV to their infants ('cases') and 266 non-transmitting controls.

METHODS

HIV-infected children and controls were pair-matched for high-risk delivery, race and year of delivery. GBV-C status was determined in maternal plasma samples obtained at or within 3 months of delivery.

RESULTS

Pregnant women with GBV-C viraemia (11% of those studied) had lower HIV RNA levels (P=0.01) and higher CD4 percentages (P=0.0006) [corrected] than women without GBV-C. A trend towards decreased mother-to-child transmission in the multivariate analysis was observed among GBV-C viraemic women delivering after highly active antiretroviral therapy (HAART) became available [odds ratio (OR) 0.30, 95% confidence interval (CI) 0.08-1.05; P=0.06], but not in women delivering prior to the widespread use of HAART.

CONCLUSIONS

GBV-C viraemia was associated with a beneficial effect on CD4 percentage and HIV RNA level in these pregnant women, and was also associated with a trend towards reduced risk of mother-to-child HIV transmission among women after HAART became available. Further studies with larger or multiple cohorts are necessary to assess possible benefits in this population.

Detection of oesophageal intubations using cuff pressures in a pig trachea–oesophagus model

BACKGROUND

The cuff pressures may be different in oesophageal and tracheal intubations. We conducted a study to evaluate if cuff pressures of endotracheal tubes (ETTs) could provide information to distinguish tracheal or oesophageal intubations in a pig trachea-oesophagus model.

METHODS

In each preparation of pig trachea-oesophagus model, the trachea and the oesophagus were intubated separately with a cuffed ETT, and the cuff pressures were measured after each 1 ml increment of air (1-10 ml) during inflation. The cuff pressures and the pressure-volume relationships in both intubations were compared.

RESULTS

The cuff pressures of oesophageal intubations were significantly higher than those of tracheal intubations in all comparisons from 1 to 10 ml of cuff volumes (P < 0.05). The cuff pressure-volume curve was steeper in the oesophageal intubation group, and the difference between the two curves was the largest when the cuff volume was 4-5 ml.

CONCLUSIONS

We conclude that the cuff pressures may be useful in detecting oesophageal intubations. This method is faster than other confirmation measures as it can detect inadvertent oesophageal intubations at the time of inflating the cuffs.

Life expectancy of patients with newly-diagnosed HIV infection in the era of highly active antiretroviral therapy

BACKGROUND

Limited data are available on the life expectancy of patients with newly-diagnosed HIV infection in the era of highly active antiretroviral therapy (HAART).

AIM

To provide such an estimate using a semi-parametric projection.

DESIGN

Statistical analysis.

METHODS

Follow-up data for patients newly diagnosed with HIV infection in Taiwan (HIV/AIDS Cohort) from 1 May 1997 to 30 April 2003 (n = 3351, only 1% are injecting drug users) were analysed using the Kaplan-Meier method. The survival function for an age- and gender-matched reference population was generated by the Monte Carlo method from the life-table of the general population. A constant excess hazard model was used to project long-term survival of HIV-infected patients, with linear extrapolation of a logit-transformed curve of survival ratio between HIV-infected patients and the reference population.

RESULTS

The 5-year survival rate was 58% in patients who had already developed AIDS at diagnosis (AIDS group), and 89% in those who had not (non-AIDS group). Extrapolation yielded an expected mean survival time of 10.6 years after diagnosis for the AIDS group, and 21.5 years after diagnosis for the non-AIDS group.

DISCUSSION

Our results support the expansion of HIV screening programs to minimize delay in diagnosis. With continuing advances in HAART, this estimate of survival in initially asymptomatic patients may be conservative. Their long life expectancy raises questions about what kind of preventive heath services should be offered. These should be addressed through further analysis of overall benefit and cost-effectiveness.

Br2 molecular elimination in 248nm photolysis of CHBr2Cl by using cavity ring-down absorption spectroscopy

Elimination of molecular bromine is probed in the B (3)Pi(ou) (+)<--X (1)Sigma(g) (+) transition following photodissociation of CHBr(2)Cl at 248 nm by using cavity ring-down absorption spectroscopy. The quantum yield for the Br(2) elimination reaction is determined to be 0.05+/-0.03. The nascent vibrational population ratio of Br(2)(v=1)Br(2)(v=0) is obtained to be 0.5+/-0.2. A supersonic beam of CHBr(2)Cl is similarly photofragmented and the resulting Br atoms are monitored with a velocity map ion-imaging detection, yielding spatial anisotropy parameters of 1.5 and 1.1 with photolyzing wavelengths of 234 and 267 nm, respectively. The results justify that the excited state promoted by 248 nm should have an A(") symmetry. Nevertheless, when CHBr(2)Cl is prepared in a supersonic molecular beam under a cold temperature, photofragmentation gives no Br(2) detectable in a time-of-flight mass spectrometer. A plausible pathway via internal conversion is proposed with the aid of ab initio potential energy calculations. Temperature dependence measurements lend support to the proposed pathway. The production rates of Br(2) between CHBr(2)Cl and CH(2)Br(2) are also compared to examine the chlorine-substituted effect.

248nm photolysis of CH2Br2 by using cavity ring-down absorption spectroscopy: Br2 molecular elimination at room temperature

Following photodissociation of CH2Br2 at 248 nm, Br2 molecular elimination is detected by using a tunable laser beam, as crossed perpendicular to the photolyzing laser beam in a ring-down cell, probing the Br2 fragment in the B 3Piou+ -X 1Sigmag+ transition. The nascent vibrational population is obtained, yielding a population ratio of Br2(v = 1)Br2(v = 0) to be 0.7 +/- 0.2. The quantum yield for the Br2 elimination reaction is determined to be 0.2 +/- 0.1. Nevertheless, when CH2Br2 is prepared in a supersonic molecular beam under cold temperature, photofragmentation gives no Br2 detectable in a time-of-flight mass spectrometer. With the aid of ab initio potential energy calculations, a plausible pathway is proposed. Upon excitation to the 1B1 or 3B1 state, C-Br bond elongation may change the molecular symmetry of Cs and enhance the resultant 1 1,3A'-X 1A' (or 1 1,3B1-X 1A1 as C2v is used) coupling to facilitate the process of internal conversion, followed by asynchronous concerted photodissociation. Temperature dependence measurements lend support to the proposed pathway.

Reaction of cyanoacetylene HCCCN(XΣ+1) with ground-state carbon atoms C(P3) in cold molecular clouds

The reaction of the simplest cyanopolyyne, cyanoacetylene [HCCCN(X (1)Sigma(+))], with ground-state atomic carbon C((3)P) is investigated theoretically to explore the probable routes for the depletion of the famed interstellar molecule HCCCN, and the formation of carbon-nitrogen-bearing species in extraterrestrial environments particularly of ultralow temperature. Six collision complexes (c1-c6) without entrance barrier as a result of the carbon atom addition to the pi systems of HCCCN are located. The optimized geometries and harmonic frequencies of the intermediates, transition states, and products along the isomerization and dissociation pathways of each collision complex are obtained by utilizing the unrestricted B3YLP6-311G(d,p) level of theory, and the corresponding CCSD(T)/cc-pVTZ energies are calculated. Subsequently, with the facilitation of Rice-Ramsperger-Kassel-Marcus (RRKM) and variational RRKM rate constants at collision energy of 0-10 kcal/mol, the most probable paths for the titled reaction are determined, and the product yields are estimated. Five collision complexes (c1-c3, c5, and c6) are predicted to give the same products, a chained CCCCN (p2)+H, via the linear and most stable intermediate, HCCCCN (i2), while collision complex c4 is likely to dissociate back to C+HCCCN. The study suggests that this class of reaction is an important route to the destruction of cyanoacetylene and cyanopolyynes in general, and to the synthesis of linear carbon-chained nitriles at the temperature as low as 10 K to be incorporated in future chemical models of interstellar clouds.

Re-emergence of meningococcal disease in Taiwan: circulation of domestic clones of Neisseria meningitidis in the 2001 outbreak

The annual incidence of meningococcal disease (meningitis and septicaemia) in Taiwan was 0.94/10(5) population in 1953. It then declined to below 0.001 from 1980 to 1987, and re-emerged in 2000 with a rate of 0.07/10(5) population. In 2001 there was a further increase in incidence (43 cases, 0.19/10(5)). Of 43 isolates of Neisseria meningitidis available for this study, including 41 from patients treated in 2001, three (7.0%) were penicillin insensitive (MIC > or = 0.12 microg/ml), though all were beta-lactamase negative: 16 (37.2%) were resistant to trimethoprim-sulphamethoxazole (MIC > or = 4/76 microg/ml). Serogrouping and genotype analysis revealed nine domestic clones. None of the 43 patients had any relationship (travel or contact history) with the 2000 or 2001 Hajj pilgrimage. Epidemiological information and typing results suggested wide dissemination of a limited number of domestic clones of N. meningitidis, manifesting as serogroups W-135, B and Y. Two clones of serogroup W-135 involved in the outbreak were genetically distinct from the 2000 or 2001 Hajj-related W-135 clone.

Coupled reduction of chlorinated hydrocarbons and heavy metals by zerovalent silicon

The feasibility of using zerovalent silicon (Si0) as a novel reductant to remove chlorinated compounds and heavy metals in contaminated sites was investigated. The kinetics and degradation mechanism of carbon tetrachloride (CT) by Si0 were also examined. Results showed that zerovalent silicon could effectively dechlorinate the chlorinated compounds. A nearly complete dechlorination of CT by Si0 was obtained within 14 h. The produced concentrations of chloroform (CF) accounted for 71-88% loss of CT, showing that reductive dechlorination is the major degradation pathway for the degradation of chlorinated hydrocarbons by Si0. The degradation followed pseudo first-order kinetics and the normalized surface reaction rate constant (k(sa)) for CT dechlorination ranged between 0.0342 and 0.0454 L m(-2) h(-1) when CT concentrations were in the range of 3-20 microM. A linear relationship between the k(sa) and pH value was also established. In addition, zerovalent silicon has a high capability in the removal of heavy metals. 83% of Cr(VI) was removed by 0.5g Si0 within 5 h, which is higher than that by Fe0. The removal efficiency of divalent metal ions by Si0 followed the order of Cu(II) > Pb(II) > Ni(II). This indicates that zerovalent silicon is an alternative reductant and can undergo coupled reduction of heavy metals and chlorinated hydrocarbons in contaminated groundwater.

Effects of huangqi jianzhong tang on hematological and biochemical parameters in judo athletes

AIM

The purpose of the study was to investigate the effects of Huangqi Jianzhong Tang (HQJZT) on hematological and biochemical parameters in judo athletes.

METHODS

Sixteen male and eight female judo athletes in Hsin-Ming senior high school were randomly and stratified divided into control and experimental group, which received placebo and HQJZT respectively during the five-week training program. The measurement of the hematological and biochemical parameters was performed twice, just before and after the training. The data was analyzed with paired-t test and ANOVA.

RESULTS

The values of RBC, Hb, and Hct were obvious decreased after intervention, while the value of GOT, GPT, BUN, and CK was elevated.

CONCLUSION

The results indicated the hematological and biochemical changes were caused by the physical training but not the effects of HQJZT. The HQJZT had no adverse effects on the judo athletes in our study.

A school waterborne outbreak involving both Shigella sonnei and Entamoeba histolytica

In an outbreak of gastroenteritis affecting 730 students, Shigella sonnei and Entamoeba histolytica were isolated from the stool specimens of patients. Environmental investigations revealed the source of infection to be contamination of underground well water by sewage from a toilet. The outbreak ended with the closure of the well water supply. To avoid such problems, institutions and other groups that maintain their own wells, including schools and summer camps, need to be vigilant about maintenance and check for potential contamination.

No increase in rates of early-onset neonatal sepsis by non-group B Streptococcus or ampicillin-resistant organisms

OBJECTIVE

We assessed the impact of a risk-based approach to group B Streptococcus (GBS) prophylaxis on the rates of early-onset neonatal sepsis (EONS).

STUDY DESIGN

A retrospective cohort study of neonates born at a tertiary-care hospital from 1990 to 1996 was performed. Cases of EONS were identified among neonates born in a period without GBS prophylaxis (1990-1992) and compared with those born in a period with GBS prophylaxis (1993-1996). The antibiotic susceptibility data on each organism isolated in the blood culture were obtained.

RESULTS

In the period without prophylaxis, 99 cases of EONS were identified among 25,934 neonates for a rate of 3.8 per 1000 births. In the period with prophylaxis, 90 cases of EONS occurred among 34,262 neonates for a rate of 2.6 per 1000. The rate of GBS-EONS significantly decreased between the 2 periods (from 1.9 to 1.1, P =.01). There was a trend toward a decrease in the rate of EONS caused by non-GBS gram-positive organisms (from 1.2 to 0.7, P =.06). There was no significant increase in the rate of EONS caused by gram-negative or ampicillin-resistant organisms.

CONCLUSIONS

A risk-based approach to GBS prophylaxis reduced the incidence of GBS-EONS at a tertiary-care hospital. This decrease was not accompanied by an increase in the incidence of EONS by non-GBS or ampicillin-resistant organisms.

Increased risk of cesarean delivery with advancing maternal age: indications and associated factors in nulliparous women

OBJECTIVE

To investigate factors that contribute to the increased risk of cesarean delivery with advancing maternal age.

STUDY DESIGN

We reviewed demographic and ante- and intrapartum variables from a data set of term, nulliparous women who delivered at Brigham and Women's Hospital in 1998 (n = 3715).

RESULTS

Cesarean delivery rates increased with advancing maternal age (< 25 years, 11.6%; > or = 40 years, 43.1%). Older women were more likely to have cesarean delivery without labor (< 25 years, 3.6%; > or = 40 years, 21.1%). Malpresentation and prior myomectomy were the indications for cesarean delivery without labor that were more prevalent in our older population as compared to our younger population. Even among women with spontaneous or induced labor, cesarean delivery rates increased with maternal age (< 25 years, 8.3%; > or = 40 years, 30.6%). Cesarean delivery rates were higher with induced labor, and rates of induction rose directly and continuously with maternal age, especially the rate of elective induction. Cesarean delivery for failure to progress or fetal distress was more common among older parturients, regardless of whether labor was spontaneous or induced. Among women who underwent cesarean delivery because of failure to progress, use of oxytocin and length of labor did not vary with age.

CONCLUSIONS

Older women are at higher risk for cesarean delivery in part because they are more likely to have cesarean delivery without labor. However, even among those women who labor, older women are more likely to undergo cesarean delivery, regardless of whether labor is spontaneous or induced. Part of the higher rate among older women who labor is explained by a higher rate of induction, particularly elective induction. Among women in both spontaneous and induced labor, cesarean delivery for the diagnoses of failure to progress and fetal distress was more frequent in older patients, although management of labor dystocia for these patients was similar to that for younger patients.

Tobacco, betel quid, alcohol, and illicit drug use among 13- to 35-year-olds in I-Lan, rural Taiwan: prevalence and risk factors

OBJECTIVES

This study determined the prevalence of and risk factors for substance use among rural Taiwanese.

METHODS

We used a survey of a representative sample of 6318 participants aged 13 to 35 years in I-Lan, Taiwan, in 1996 through 1997.

RESULTS

Perceived use of illicit drugs by peers, tobacco smoking, betel quid chewing, and male gender were the strongest predictors of illicit drug use. The prevalence of illicit drug use ranged from 0.3% among those who did not use any other substance to 7.1% among those using tobacco, betel quid, and alcohol.

CONCLUSIONS

Preventive measures should address substance use in general rather than aiming at single substances.

Improving storage efficiency of vector quantization codebook for physiological quasi-periodic signals

A quasi-periodic signal is a periodic signal with period and amplitude variations. The electrocardiogram (ECG) and several physiological signals can be treated as quasi-periodic. Vector quantization (VQ) is a valuable and universal tool for signal compression. However, the periodicity of a quasi-periodic signal causes data redundancy in the VQ codebook, where many codevectors are highly correlated. This paper explores the codebook (CB) redundancy in order to increase storage efficiency for physiological quasi-periodic signals. A quantitative CB redundancy measure and two redundancy reducing algorithms are proposed. Both algorithms use a mixed CB structure containing one and two-dimensional CBs. The first algorithm is applied to a CB directly, and the second one uses an LBG-like training algorithm to obtain a storage-efficient CB from a set of training vectors. With the MIT/BIH ECG database, the experimental results show that both algorithms can reduce the CB redundancy effectively with essentially no loss of signal quality. For comparison, the mean-shape VQ (MSVQ) proposed by Cárdenas-Barrera and Lorenzo-Ginori for ECG compression is implemented and the resulting average percent of the root-mean-square difference (PRD) is 10.78%. By using the first algorithm, the CB storage space is reduced by 40% and the resulting average PRD is 10.87%. The second algorithm can reduce the CB storage space by 75% and the average PRD is 10.27%, which is even better than the original MSVQ.

Identification of Atractylodes plants in Chinese herbs and formulations by random amplified polymorphic DNA

AIM

An efficient, precise, and sensitive method for identifying Atractylodes plants has been established and will contribute significantly to quality control and scientific analysis in Chinese traditional medicine.

METHODS

Twenty primers were applied for setting up the RAPD (randomly amplified polymorphic DNA) markers of Atractylodes plants, Atractylodes lancea DC (A lancea DC), Atractylodes japonica Koidz (A japonica K), and Atractylodes ovata DC (A ovata DC). The primer OPF03, OPF05, and OPF14 could discriminate them successfully. The results were also able to apply on the Chinese formulations with Atractylodes purchased from local markets.

RESULTS

RAPD was used to investigate phylogenetic relationships among and within closely related species. RAPD analysis reflects heritable changes in the nucleotides sequence in both the coding and noncoding regions, because it is conducted directly from the DNA level. This work first conducted RAPD analysis of Atractylodes plants to establish their RAPD makers.

CONCLUSION

The RAPD markers could be applied extensively in the Chinese herbal formulations.

Helicobacter pylori infection induced alteration of gene expression in human gastric cells

BACKGROUND

Helicobacter pylori, a human pathogen responsible for many digestive disorders, induces complex changes in patterns of gene expression in infected tissues. cDNA expression arrays provide a useful tool for studying these complex phenomena.

AIM

To identify genes that showed altered expression after H pylori infection of human gastric cells compared with uninfected controls.

METHODS

The gastric adenocarcinoma cell line AGS was cocultivated with H pylori. Growth of infected cells was determined by trypan blue exclusion assay. Complementary DNA probes derived from H pylori treated and untreated cells were hybridised to two identical Atlas human cDNA expression arrays, and those genes with altered expression levels were identified. A real time quantitative reverse transcription-polymerase chain reaction assay was used to better define expression patterns of these genes in endoscopically gastric mucosal biopsies with and without H pylori infection.

RESULTS

Over 24 hours, coincubation with H pylori inhibited AGS cell growth but did not cause a noticeable degree of cell death. H pylori treatment altered the pattern of gene expression in AGS cells. We identified 21 overexpressed genes and 17 suppressed genes from the cDNA expression arrays. The majority of genes were transcription factors such as c-jun, BTEB2, and ETR101. Other genes were involved in signal transduction pathways, such as MAP kinase, interleukin 5, and insulin-like growth factor. Genes involved in cell cycle regulation and differentiation, such as CDC25B and NM23-H2, were also identified. In patients with H pylori infection (n=20), there was a significant difference for ERCC3, Id-2, and NM23-H2 mRNA levels in infected gastric mucosa compared with uninfected gastric mucosa in patients without peptic diseases (n=20) (ERCC3 4.75 molecules/10(4) beta-actin mRNA molecules v 13.65, p<0.001; Id-2 16.1 v 23.4, p<0.05; NM23-H2 17.5 v 45.5, p<0.001). There was no significant difference between mRNA levels of c-jun and CDC25B in H pylori colonised gastric mucosa and uninfected mucosa.

CONCLUSION

We demonstrated that H pylori infection caused alteration of gene expression in AGS cells. The differential hybridisation technique of Atlas human cDNA expression array is a useful method to identify host genes involved in pathogenic mechanisms in H pylori infection.

Cost-effectiveness of elective cesarean delivery in human immunodeficiency virus-infected women(1)

OBJECTIVE

To evaluate the cost-effectiveness of an elective cesarean delivery strategy in human immunodeficiency virus (HIV)-infected women receiving zidovudine therapy to prevent perinatal transmission.

METHODS

A decision-analysis model was constructed to compare two delivery strategies in HIV-infected women: usual care and recommendation for elective cesarean delivery. The model followed a hypothetical cohort of 7000 HIV-infected pregnant women in the United States who were receiving zidovudine therapy for 1 year. The third-party payer perspective was taken. Cost of delivery method with and without complications and lifetime medical care cost for pediatric HIV infection were considered. The main outcome measure was cases of perinatal HIV transmission prevented.

RESULTS

Compared with the usual care strategy, the elective cesarean delivery strategy resulted in an additional 3486 cesarean deliveries each year, prevented 142 cases (52.4%) of perinatal HIV transmission, and resulted in incremental overall cost savings to society of $5.3 million per year ($37,284 saved per case of perinatal transmission prevented). With other estimates held constant, the elective cesarean delivery strategy would not be cost saving when the baseline perinatal HIV transmission rates were all reduced by 43.3%.

CONCLUSIONS

Elective cesarean delivery in HIV-infected women receiving zidovudine is one management strategy for prevention of perinatal HIV transmission and can be cost saving. However, if other strategies, such as use of combination antiretroviral therapy and/or measurement of viral load, result in at least 50% reduction of the baseline perinatal HIV transmission rates, elective cesarean delivery will not be cost saving.

Synthesis and autoxidation of new tetracyclic 9H,10H-indolizino[1,2-b]indole-1-ones

The new tetracyclic 9H,10H-indolizino[1,2-b]indole-1-one derivatives (7a-d, 7ea, 7eb) have been synthesized by modified Fischer indole synthesis from the enol ether of 2,5-dihydroxy-7-methyl-6-cyano-indolizine (3) and arylhydrazines (4a-g). Attempted N-methylation of 7a-d produced a series of autoxidized products including 10-hydroperoxy-1-methoxyindolizino[1,2-b]indole (9a-d) as the major product accompanied with methylperoxides (10a-d and 11a-d) and 2-formyl-3-(pyridine-2-yl)indole (12a, 12c) derivatives as the minor products. A plausible mechanism of the autoxidation is postulated based on the isolation of some intermediates. The reaction is thought to proceed through azaenolate/enamine intermediates following a novel type of autoxidation.

Identifying differentially expressed genes associated with metastasis of follicular thyroid cancer by cDNA expression array

Patients with follicular thyroid carcinoma have a higher incidence of metastasis than papillary thyroid carcinoma when thyroid cancer is diagnosed. The cDNA expression array technology is utilized herein to profile differentially expressed genes from metastatic human follicular thyroid carcinoma and reveal new tumor markers as well as target genes for therapeutic intervention. Tissue samples were obtained during surgical resection of the thyroid follicular carcinoma and metastatic tissue in the brain of the same patient. Two identical Atlas human cDNA expression arrays were hybridized with 32P-labeled cDNA probes derived from RNA of either primary thyroid cancer or metastatic tissue. Parallel analysis of the hybridized signals allowed us to identify the alteration of gene expression in the metastasis process. Eighteen genes significantly overexpressed and 40 genes significantly underexpressed were identified in the metastatic thyroid cancer. Genes that displayed an altered expression were associated with the processes of cell cycle regulation, apoptosis, DNA damage response, angiogenesis, cell adhesion and mobility, invasion, and immune response. An expression profile of genes that are associated with metastasis process of follicular thyroid cancer was also discussed. Further investigation is required to understand the precise relationship between the altered expression of these genes and the metastasis process of follicular thyroid cancer.

Cardiac beriberi among illegal mainland Chinese immigrants

The most common symptoms of chronic beriberi due to thiamine deficiency include dyspnoea, fatigue, leg oedema, lower extremity weakness and numbness. When collapsed peripheral circulation, metabolic acidosis, or shock are present, the disease has advanced from chronic beriberi to pernicious or fulminating beriberi heart failure (Shoshin beriberi). We report two patients with fulminating beriberi; both of whom had been incarcerated at a detention centre for 5 months before hospitalization. A prolonged monotonous diet, low in thiamine, was a major risk factor in both patients. Thiamine deficiency should be considered for any patient with symptoms and signs compatible with beriberi.

Prevalence of type 2 diabetes mellitus in Taiwan: ethnic variation and risk factors

The purpose of this study was to compare the prevalence of diabetes and risk factors for the disease in three ethnic groups in Taiwan; the Hakaas, Fukienese, and aborigines. A cross-sectional study of men and women aged 50-79 years were invited to attend a standardized interview and physical examination. Diabetes mellitus was defined as a fasting plasma glucose (concentration of greater than or = 126) or a previous diagnosis of diabetes. Demographic, socioeconomic, and risk factor data were obtained. A total of 1293 persons (468 Hakaas, 440 Fukienese, and 385 aborigines) completed the examination. Hakaas had the highest age-adjusted prevalence of diabetes, 17.9% in men and 15.5% in women, followed by Fukienese, 14.5% in men and 12.8% in women. Aborigines had a prevalence of 10.0% in men and 13.3% in women. Diabetes prevalence was positively associated with family history of diabetes, obesity, hypertension, and hypertriglyceridemia. The ethnic variation in diabetes prevalence was reduced after adjustment for age, sex and significant factors. The multivariate-adjusted odds ratios (95% confidence interval) were 1.27 (0.76-2.12) for Fukienese and 1.44 (0.89-2.33) for Hakaas compared with aborigines. Diabetes mellitus is a major public health problem in Taiwan and warrants prevention efforts tailored to the country's different ethnic groups.

Biodegradable alginate antibiotic beads

The authors investigated the poly-L-lysine-coated alginate beads as an antibiotic delivery system for the treatment of various surgical infections. The sodium alginate was mixed with vancomycin, coated with poly-L-lysine, and lyophilized to form five types of the biodegradable antibiotic beads. Type I, 2.5% alginate, nonpoly-L-lysine coated and nonlyophilized; Type II, 2.5% alginate, poly-L-lysine coated but nonlyophilized; Type III, 2.5% alginate, poly-L-lysine coated and lyophilized; Type IV, 5% alginate, poly-L-lysine coated and lyophilized; and Type V, 7.5% alginate, poly-L-lysine coated and lyophilized. Cytotoxicity of the alginate beads to fibroblasts and HeLa cells was evaluated by the MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide] colorimetric assay. A study of in vitro elution of vancomycin of the alginate antibiotic beads was performed. The results suggested that the alginate antibiotic beads present no obvious toxic risk to their use as a drug delivery system. The concentration of vancomycin in these five types of beads was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial killing and resistance to the antibiotic) for 9,11,12, 14, and 17 days respectively. The release was most marked during the first 3 days. The duration of antibiotic release was prolonged by using techniques of poly-L-lysine coating, lyophilization, and by increasing the content of alginate. This study offers a biodegradable delivery system of antibiotics to treat various surgical infections.

Cytology of small-cell carcinoma arising in Barrett's esophagus

The cytologic and histologic features of a rare case of small-cell carcinoma arising in Barrett's esophagus are reported. The patient presented with progressive dysphagia and an endoscopy revealed a distal esophageal mass with luminal constriction. The brushing smears showed small-cell carcinoma and dysplastic glandular epithelium. The concomitant biopsy confirmed the diagnosis of small-cell carcinoma arising in Barrett's esophagus.

Expression of sodium iodide symporter in metastatic and follicular human thyroid tissues

Active iodide uptake across the basal membrane mediated by human sodium iodide symporter (hNIS) has been shown to be a process coupled with the flow of sodium. There is still controversy as to the amount of hNIS expression present in different kinds of human thyroid cancer tissues. In this study, we present a 58-year-old women with follicular thyroid carcinoma with vertebra and skull metastases. 201Tl and 5 mCi 131I scans clearly demonstrated the metastatic lesions in the brain of this patient. Thyroid and metastatic tissues were then obtained for this study, which is aimed at comparing the iodide trapping ability in vivo and in vitro of hNIS, and then comparing their expression in both thyroid tissue and metastatic tissues. Polyclonal antibodies to hNIS and competitive RT PCR were used to analyze the symporter protein and mRNA expressed in follicular human thyroid and metastatic tissues. Positive staining of the symporter protein was performed in the follicular thyroid carcinomas, otherwise, the metastatic tissues could not have demonstrated the protein in the staining. Follicular thyroid carcinoma tissues from thyroid were revealed around 5 pg hNIS expressed in follicular thyroid carcinoma tissues from the thyroid. Otherwise, there was almost an absence of hNIS expression in the metastatic tissue. These discrepancies of the expression in hNIS in vivo and in vitro studies need further investigation.

An epidemic of enterovirus 71 infection in Taiwan. Taiwan Enterovirus Epidemic Working Group

BACKGROUND

Enteroviruses can cause outbreaks of hand-foot-and-mouth disease (characterized by vesicular lesions on the hands, feet, and oral mucosa) or herpangina, usually without life-threatening manifestations. In 1998 an epidemic of enterovirus 71 infection caused hand-foot-and-mouth disease and herpangina in thousands of people in Taiwan, some of whom died.

METHODS

We assessed the epidemiologic aspects of this outbreak. Cases of hand-foot-and-mouth disease or herpangina in ambulatory patients were reported to the Taiwan Department of Health by a mean of 818 sentinel physicians. Severe cases in hospitalized patients were reported by 40 medical centers and regional hospitals. Viruses were isolated by 10 hospital laboratories and the department of health.

RESULTS

The sentinel physicians reported 129,106 cases of hand-foot-and-mouth disease or herpangina in two waves of the epidemic, which probably represents less than 10 percent of the estimated total number of cases. There were 405 patients with severe disease, most of whom were five years old or younger; severe disease was seen in all regions of the island. Complications included encephalitis, aseptic meningitis, pulmonary edema or hemorrhage, acute flaccid paralysis, and myocarditis. Seventy-eight patients died, 71 of whom (91 percent) were five years of age or younger. Of the patients who died, 65 (83 percent) had pulmonary edema or pulmonary hemorrhage. Among patients from whom a virus was isolated, enterovirus 71 was present in 48.7 percent of outpatients with uncomplicated hand-foot-and-mouth disease or herpangina, 75 percent of hospitalized patients who survived, and 92 percent of patients who died.

CONCLUSIONS

Although several enteroviruses were circulating in Taiwan during the 1998 epidemic, enterovirus 71 infection was associated with most of the serious clinical manifestations and with nearly all the deaths. Most of those who died were young, and the majority died of pulmonary edema and pulmonary hemorrhage.

Subcutaneous tumors of mice treated with rhodamine-123 and laser irradiation

BACKGROUND

Treatment involving photosensitizers and laser irradiation (LIR) in cancer therapy is known as photodynamic therapy (PDT). The purpose of our study was to assess the therapeutic effect of PDT using rhodamine-123 (Rh123) and LIR on subcutaneous tumors (ST) in mice.

METHODS

Sarcoma-180 cells (1 x 10(7)) were implanted subcutaneously into the breast area of strain Cr1:CD-1-ICR (BR) female mice. Mice bearing ST were treated with Rh123 or LIR alone, or a combination of both, once a day for 3 successive days.

RESULTS

The best therapeutic effect was observed in the group treated with 7.5 mg Rh123 per kilogram of body weight, combined with 75 J/cm2 laser irradiation energy. The group's mortality rate, tumor control rate, mean survival time, and increase in lifespan within 120 days after treatment were 16.7%, 83.3%, 109.4 days, and 135.8%, respectively. The most inhibitory effect on tumor cells was found in the group treated with 15 mg/kg Rh123 and 90 J/cm2 laser irradiation. The biosyntheses of DNA, RNA, and protein in tumor cells of this group was obviously inhibited.

CONCLUSION

PDT with the photosensitizer Rh123 and laser irradiation was therapeutically effective in treating subcutaneous tumors of mice. The tumor cells and the syntheses of DNA, RNA, and protein of the tumor cells in these PDT treated mice were obviously inhibited.

Effects of glycyrrhizae and glycyrrhizic acid on cellular immunocompetence in low-dose gamma-ray irradiated mice

BACKGROUND

For both animals and human beings, it is important to prevent damage from ionizing radiation and to restore immunocompetence following irradiation. The present study was conducted to investigate the effects of glycyrrhizae (GL) and glycyrrhetinic acid (GA) on cellular immunocompetence in low dose gamma-ray-irradiated mice.

METHODS

Six- to 8-week-old ICR strain' Crl:CD-1-ICR (BR) strain male mice, bred in the Institute of Cancer Research, U.S.A., were chosen and divided into four groups. Group A was the normal control. Group B, the experimental control, received 1 Gy of whole body gamma-ray irradiation. Groups C and D, the experimental groups, were treated with 500 mg/kg of GL (orally) and 5 mg/kg body weight of GA (i.p.), respectively, once a day, 5 days a week for 2 weeks after gamma-irradiation. The tested mice were killed, at 6 different intervals to measure their leukocyte and differential counts. Cellular immunocompetence was measured by the 3H-thymidine uptake in each group.

RESULTS

One gray of gamma-ray irradiation had evident inhibition on the leukocyte and differential counts and the cellular immunity of mice. GL and GA could help to restore the decreased leukocyte counts and the cellular immunocompetence in low dose gamma-irradiated mice.

CONCLUSION

GL and GA could help to restore decreased leukocyte counts and the cellular immunocompetence in low-dose gamma-ray-irradiated mice.