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.

The coming of age of radiation-induced hyperparathyroidism: evolving patterns of thyroid and parathyroid disease after head and neck irradiation

BACKGROUND

This study investigates the association of thyroid and parathyroid disease in radiation-exposed patients and tests the hypothesis that hyperparathyroidism (HPT) occurs after a longer latency period.

METHODS

Routine questioning identified 40 patients in the endocrine surgery clinic with a history of radiation exposure. Patients with thyroid disease were screened for HPT and vice versa.

RESULTS

The known diagnosis at initial referral was thyroid disease alone in 26 of 40 patients, HPT alone in 9 of 40 patients, and both in 5 of 40 patients. After screening was completed, a total of 18 of 40 patients were found to have both thyroid disease and HPT. HPT manifested an average of 17 years later than thyroid disease (52.6 +/- 10.0 years vs 35.5 +/- 13.8 years after radiation therapy [ P < .05]). One third of the patients with HPT had normal serum calcium levels despite elevated parathyroid hormone levels and abnormal parathyroid glands.

CONCLUSION

As the widespread use of x-ray therapy for benign childhood conditions becomes more remote, practitioners should expect a decreasing number of patients with radiation-associated thyroid disease, with an increase in HPT. Patients with radiation exposure and thyroid disease should be evaluated carefully and followed for HPT. Those patients who undergo surgical procedures should have close inspection of the parathyroid glands, with biopsy and excision when appropriate.

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.