Systemically expressed soluble Tie2 inhibits intraocular neovascularization

Retinal and choroidal neovascularization are the most frequent causes of severe and progressive vision loss. Studies have demonstrated that Tie2, an endothelial-specific receptor tyrosine kinase, plays a key role in angiogenesis. In this study, we determined whether adenovirus-mediated gene delivery of extracellular domain of the Tie2 receptor (ExTek) could inhibit experimental retinal and choroidal neovascularization. Immunofluorescence histochemistry with a monoclonal antibody to human Tie2 showed that Tie2 expression is prominent around and within the base of newly formed blood vessels of retinal and choroidal neovascular lesions. A single intramuscular injection of adenovirus expressing ExTek genes achieved plasma levels of ExTek exceeding 500 microg/ml in mice for 10 days (in neonates) and 7 days (in adults). This treatment inhibited retinal neovascularization by 47% (p < 0.05) in a murine model of ischemia-induced retinopathy. The same treatment reduced the incidence and extent of sodium fluorescein leakage from choroidal neovascular lesions by 52% (p < 0.05) and 36% (p < 0.01), respectively, in a laser-induced murine choroidal neovascularization model. The same mice showed a 45% (p < 0.001) reduction of integrated area of the choroidal neovascularization. These findings indicate that Tie2 signaling is a common component of the angiogenic pathway in both retinal and choroidal neovascularization, providing a potentially useful target in the treatment of intraocular neovascular diseases.

Three-day lansoprazole quadruple therapy for Helicobacter pylori-positive duodenal ulcers: a randomized controlled study

AIM

To compare the efficacy and tolerability of a 3-day quadruple therapy with a standard 7-day triple therapy in eradicating Helicobacter pylori infection and healing duodenal ulcers.

METHODS

Patients with H. pylori-positive duodenal ulcers were randomized to receive either lansoprazole 30 mg, clarithromycin 500 mg, and metronidazole 400 mg twice daily for 7 days (LCM-7) or lansoprazole 30 mg, clarithromycin 500 mg, metronidazole 400 mg, and bismuth subcitrate 240 mg twice daily for 3 days (LCMB-3). No pre- or post-treatment acid suppression was used. Follow-up endoscopy was performed at week 6.

RESULTS

A total of 118 patients were recruited. Sixty patients in the LCM-7 group and 53 patients in the LCMB-3 group returned for endoscopy. Intention-to-treat eradication rates were 87% and 86% (P=0.94) and per protocol eradication rates were 87% and 94% (P=0.29) in the LCM-7 and LCMB-3 groups, respectively. Per protocol and intention-to-treat ulcer healing rates were 98% and 98% in LCM-7 and 100% and 91% in LCMB-3, respectively. There were no significant differences in efficacy in relation to the initial metronidazole and clarithromycin susceptibility. Significant reduction in the duration of side-effects was found in the LCMB-3 group.

CONCLUSION

The 3-day quadruple therapy is highly effective, better tolerated and can be considered as a first-line therapy in duodenal ulcer management.

Transmission of hepatitis B infection from hepatitis B core antibody--positive liver allografts is prevented by lamivudine therapy

Donor shortage has led to the use of hepatitis B core antibody (anti-HBc)--positive (anti-HBc(+)) liver allografts for patients in need of relatively urgent orthotopic liver transplantation (OLT). Because anti-HBc(+) allografts transmit hepatitis B virus (HBV) infection at a high rate, effective prophylaxis is required. We assessed the effectiveness of lamivudine in preventing HBV transmission by anti-HBc(+) allografts. Between March 1996 and March 2000 at Cedars-Sinai Medical Center (Los Angeles, CA), 15 of 169 patients (8.9%) received liver allografts from anti-HBc(+) donors. Six patients were hepatitis B surface antigen (HBsAg)(+) (group 1), and 9 patients were HBsAg negative (HBsAg(-); group 2) before OLT. All patients were administered lamivudine, 100 or 150 mg/d, orally after OLT. Patients who were HBsAg(+) before OLT also were administered hepatitis B immunoglobulin (HBIG) prophylaxis. Hepatitis B serological tests were performed on all patients, and HBV DNA was determined in liver tissues in 10 patients. All 15 patients remained HBsAg(-) at their last follow-up 2 to 40 months (mean, 17 months) post-OLT. All patients in group 1 had antibody to HBsAg (anti-HBs) titers greater than 250 mIU/mL post-OLT (mean follow-up, 20 months; range, 7 to 40 months). Of the 2 patients in group 1 who underwent liver biopsy after OLT, 1 patient had detectable hepatic HBV DNA despite being anti-HBs(+) and HBsAg(-). Among the patients in group 2, none acquired anti-HBc or HBsAg. Hepatic HBV DNA was undetectable in the 7 patients in group 2 who underwent liver biopsy after OLT. Anti-HBc(+) allografts can be safely used in patients who undergo OLT for chronic hepatitis B and susceptible transplant recipients if prophylaxis with combination HBIG and lamivudine or lamividine alone is administered after OLT, respectively. However, more data are needed to determine the efficacy of lamivudine monotherapy in preventing transmission of HBV infection from anti-HBc(+) liver allografts to susceptible recipients.

Macular hole after laser in situ keratomileusis and photorefractive keratectomy

PURPOSE

To describe three myopic patients who developed unilateral macular hole after undergoing bilateral laser in situ keratomileusis or photorefractive keratectomy.

METHODS

Case reports.

RESULTS

Three eyes of three myopic patients developed a macular hole in one eye after bilateral laser in situ keratomileusis or photorefractive keratectomy. The macular hole formed between 4 to 7 weeks after laser in situ keratomileusis in case 1 (a 48-year-old woman), and within 2 months after laser in situ keratomileusis in case 2 (a 36-year-old woman). In case 3 (a 45-year-old man), the macular hole was found 9 months after photorefractive keratectomy. A vitrectomy closed the macular hole of case 1 with final best-corrected visual acuity of 20/25 and case 2 with 20/30, whereas case 3 declined further surgery.

CONCLUSION

A macular hole may develop in myopic eyes after laser in situ keratomileusis or photorefractive keratectomy. Vitreoretinal interface changes may play a role.

Risk Factors for Prophylaxis Failure in Patients Receiving Aerosol Pentamidine for Pneumocystis carinii Pneumonia Prophylaxis

OBJECTIVE

The purposes of this study were (1) to determine the incidence of prophylaxis failure in HIV-infected patients receiving aerosol pentamidine (AP) for Pneumocystis carinii pneumonia (PCP) prophylaxis, and (2) to identify risk factors for PCP prophylaxis failure.

SETTING AND DESIGN

In Ontario, Canada, AP has been made available for outpatient PCP prophylaxis through a centralized government program, the Ontario Drug Distribution and Monitoring Program. Data from this administrative observational database were extracted for 2,227 patients who received AP between May 1989 and December 1998.

OUTCOME MEASUREMENTS

The incidence of breakthrough PCP (BPCP) was calculated from the database. A Cox regression model with time-varying covariates was created to examine factors associated with BPCP. The follow-up time was divided into three eras: 1989 to 1991, 1992 to 1994, and 1995 to 1998. These eras were meant to reflect major changes in antiretroviral medication regimens.

RESULTS

The overall risk of BPCP was 16.2% over a mean follow-up of 1.67 years. The overall BPCP rate was 9.7/100 patient-years, with rates of 8.8/100, 13.1/100, and 6.3/100 patient-years in each of the three treatment eras. In the multivariate analysis, significant risk factors for prophylaxis failure were low CD4 count, previous diagnosis of PCP, history of AIDS-defining conditions other than PCP, and antiretroviral treatment era defined above.

CONCLUSION

The overall rate of PCP prophylaxis failure has decreased significantly after 1995, coincident with the era of highly active antiretroviral therapies. Initiation of PCP prophylaxis remains necessary in patients with risk factors.

Community acquired pneumonia (CAP): an update

Community-acquired pneumonia (CAP) remains a common and serious infectious disease worldwide. Recent investigations highlight the difficulties in making etiological diagnosis while emphasizing the importance of atypical pathogens in CAP. Prognostic tools such as the pneumonia severity index have been validated and widely endorsed as an aid in making site of care decisions in managing CAP patients. Empiric treatment guidelines for CAP have been developed and their use has been shown to simplify treatment regimens and improve outcome.

Combined diffusion model for the sorption of cadmium, copper, and zinc ions onto bone char

The ability of bone char to remove three single-component metals (namely, cadmium, copper and zinc) from aqueous solutions has been studied. Equilibrium isotherms have been measured and analyzed using a Langmuir isotherm model. A series of batch contact time experiments were performed to study the effect of sorbent mass and initial metal ion concentration for the three systems. A new film-pore diffusion model has been applied to the batch contact time results, and good correlation is obtained between theoretical predictions and experimental data. A further extension to the new model was made to include a surface diffusion term. The agreement between theoretical results and experimental data improved as the sum of the squares of the errors (SSE) improved by around 20% for cadmium and zinc but by 50% for copper. Therefore, the sorptions of cadmium and zinc ions onto bone char are primarily film-pore diffusion controlled, but for the copper system film-pore-surface diffusion must be considered.

An evaluation of invasive and non-invasive tests for the diagnosis of Helicobacter pylori infection in Chinese

BACKGROUND

Different tests are available for diagnosing Helicobacter pylori infection.

AIM

To compare the most commonly used tests either alone or in combination in Chinese patients with respect to routine clinical use or research purpose.

METHODS

A total of 294 consecutive dyspeptic patients without previous H. pylori treatment were recruited. During upper endoscopy, biopsies were taken from the antrum and corpus, for a commercially available CLO-test, an in-house rapid urease test, culture, polymerase chain reaction and histological examination. Patients then received a 13C-urea breath test. The H. pylori status of each patient was determined by a concordance of test results.

RESULTS

For routine clinical use, histology (antral plus corpus biopsies) had an accuracy of 100%, whilst the rapid urease test had an accuracy of 99.7%. The 13C-urea breath test was equally reliable, with an accuracy of 94.5%. Combinations of two tests did not confer additional advantage over the most accurate single test. For research purposes, the accuracy of using the criteria of two positives out of three diagnostic tests was 100% and equivocal results were not found.

CONCLUSION

Histology with or without a rapid urease test was highly accurate for routine clinical use. Alternatively, the 13C-urea breath test was an equally reliable non-invasive test. The two positives out of three tests approach was highly reliable in predicting H. pylori status of untreated Chinese patients in a research setting.

One-week ranitidine bismuth citrate-based triple therapy for the eradication of Helicobacter pylori in Hong Kong with high prevalence of metronidazole resistance

AIM

To compare 1-week ranitidine bismuth citrate-based (RBC) triple therapy vs. omeprazole-based (O) triple therapy for the eradication of Helicobacter pylori infection in Hong Kong with high prevalence of metronidazole resistance.

METHODS

Patients with non-ulcer dyspepsia and H. pylori infection were randomized to receive either: (i) RBCCM: ranitidine bismuth citrate (pylorid) 400 mg, clarithromycin 250 mg and metronidazole 400 mg; or (ii) OCM: omeprazole 20 mg, clarithromycin 250 mg and metronidazole 400 mg, each given twice daily for 1 week. Endoscopy (CLO test, histology and culture) and 13C-urea breath test were performed before randomization and 6 weeks after drug treatment.

RESULTS

A total of 180 patients were randomized. H. pylori eradication rates (intention-to-treat, n=180/per protocol, n=166) were 83%/92% for RBCCM and 66%/70% for OCM (P=0.01, intention-to-treat and P=0.001, per protocol, respectively). RBCCM treatment was unaffected by metronidazole susceptibility and achieved a significantly higher eradication rate in metronidazole-resistant cases (89%) than the OCM group (45%, P=0.0064).

CONCLUSION

One-week ranitidine bismuth citrate-based triple therapy is significantly better than omeprazole-based triple therapy for the eradication of H. pylori infection, especially in metronidazole-resistant cases. It is an effective regimen for the eradication of H. pylori infection in regions with a high prevalence of metronidazole resistance.

Mutation of proline 409 to arginine in the meander region of cytochrome p450c17 causes severe 17 alpha-hydroxylase deficiency

We elucidated the molecular basis of 17 alpha-hydroxylase deficiency in a Chinese patient with male pseudohermaphroditism. The patient is a compound heterozygote, carrying two different mutant alleles in the CYP17 gene. The first mutation, g.6333--6341delGACTCTTTCA, located in exon 8, was reported in a Thai patient living in a rural village in Thailand. We suggest that g.6333--6341delGACTCTTTCA may be a prevalent mutation causing P450c17 deficiency in Southeast Asia. The second mutation is a missense mutation, g.5582C>G, located in exon 7, changing the codon 409 from CCG to CGG, and changing the coded amino acid from proline to arginine, i.e., P409R. This proline residue is conserved in P450c17 of other species and other human P450 proteins. Site-directed mutagenesis, in vitro expression, and functional analysis of the P409R mutant in COS-1 cells show that it has a complete lack of 17 alpha-hydroxylase activity. The proline residue probably causes a turn in the meander region of P450c17, and we hypothesize, by comparison to homologous proteins, that the change in the protein conformation may abolish heme incorporation or may prevent P450c17 from interacting with electron donors.

Experimental study of the sampling artifact of chloride depletion from collected sea salt aerosols

Sampling artifact of chloride depletion from collected sea salt particles was studied, based on simultaneous measurements of size distribution measurements by a 10-stage Micro-Orifice Uniform Deposit Impactor (MOUDI) and of PM2.5 measurements by a Compact Porous Metal Denuder Sampler (PMDS) at a coastal site in Hong Kong on May 7, 8, 9, 11, and 29, 1998. The ambient concentrations of SO2, HNO3, HNO2, and NH3 were also measured by the PMDS. PM2.5 measurements by the PMDS, which is equipped with denuders and nylon back filters, are compared with the PM1.8 and PM3.1 measurements by the MOUDI. The percentages of chloride depletion from sea salt aerosols in PM1.8 and PM3.1 were 4-45% higher than that in PM2.5. This suggests that chloride evaporation in PM1.8 and PM3.1 collected on Teflon filters of the MOUDI during sampling was present. From the sum of the contributions of particles on the Teflon and nylon filters of the PMDS, nitrate formation almost completely accounts for chloride depletion in PM2.5 prior to collection since the equivalent ratio of [Na+] to ([NO3-] + [Cl-]) is close to the seawater ratio of 0.85. However, it was found that 22-74% of nitrate and 45-86% of chloride in the collected particles on the Teflon filter of the PMDS evaporated during sampling. Excess chloride depletion unexplained by NO3- and nss-SO4(2-) was found in the collected particles on the Teflon filter of the PMDS. Similarly, an amount of 3.7-27.2 nequiv m-3 of excess depleted chloride (equivalent to 8-55% of total chloride depletion) was found in supermicron particles collected by the MOUDI. In the 1.8-3.1 microns particles, the excess depleted chloride is positively correlated to the chloride evaporated from the deposited particles. Particle--particle interactions are proposed to explain the evaporation of nitrates and chlorides in the PMDS and MOUDI measurements. The observed chloride depletion from seasalt aerosols was partially attributed to sampling artifact due to particle--particle interactions.

Atovaquone suspension for treatment of Pneumocystis carinii pneumonia in HIV-infected patients

OBJECTIVE

To describe clinical experience with atovaquone suspension for the treatment of Pneumocystis carinii pneumonia (PCP) in HIV-infected patients.

DESIGN

A retrospective chart review.

METHODS

The medical records of 54 HIV-infected patients with PCP treated with atovaquone were examined. The outcomes of 34 patients treated with atovaquone suspension (750 mg twice a day) were compared with those of 20 patients treated with atovaquone tablets (750 mg three times a day).

RESULTS

The proportion of patients successfully treated was similar with the suspension (74%) and tablet (70%) formulations of atovaquone. The proportion of patients with an inadequate response to therapy was lower for patients treated with atovaquone suspension (15%) than tablets (30%). Both formulations were well tolerated.

CONCLUSION

Atovaquone suspension is effective and well tolerated for the treatment of PCP.

Photocatalytic thin film cascade reactor for treatment of organic compounds in wastewater

The photocatalytic oxidation of benzoic acid was investigated in a pilot scale-cascade photoreactor. The photoreactor consists of an array of UV lamps (40 W, 365 nm) illuminating a cascade of three inclined 316 stainless steel plates, on which titanium dioxide (TiO2) was immobilized by electrophoretic deposition. The percentage removal of total organic carbon (TOC) of liquid samples was determined. The photocatalytic process was affected by several operating parameters. Increasing the solution temperature was found to reduce the dissolved oxygen (DO) level and to decrease the rate of the degradation process. The Langmuir-Hinshelwood equation was found to be accurate for modeling the degradation of benzoic acid with initial concentrations of 50 ppm, 75 ppm and 100 ppm. The rate of removal of TOC was positively affected by UV light intensity, but appeared to be independent of solution flowrate in the range examined. Control experiments confirmed that the effects of adsorption of the solute onto the TiO2 catalysts and photolytic degradation were negligible.

Enhancement of MSH receptor- and GAL4-mediated gene transfer by switching the nuclear import pathway

Efficient nuclear delivery of plasmid DNA represents a major barrier in nonviral gene transfer. One approach has been to use DNA-binding proteins such as GAL4 from yeast as DNA carriers with nuclear targeting properties. We recently showed, however, that GAL4 is inefficient in targeting DNA to the nucleus because its DNA-binding and nuclear targeting activities are mutually exclusive, which relates to the fact that GAL4 nuclear import occurs via a novel pathway. Here, we 'switch' this pathway to a more conventional one by adding a modified poly-lysine to which an optimized nuclear targeting signal, based on that of the SV40 large T-antigen, is linked. We also use a chimeric GAL4-alpha-melanocyte stimulating hormone (MSH) fusion protein to enable gene transfer to cells expressing the MSH receptor. Switching the nuclear import pathway of the transfecting complex significantly enhances receptor-mediated gene transfer through enabling interaction with desired components of the cellular nuclear import machinery. The present study represents the first demonstration that nuclear targeting signals can enhance receptor-mediated gene delivery, the approaches having important relevance to research and clinical applications, such as in generating transgenic or knock-out animals, or in gene therapy.

Evaluation of a new referral system for the management of dyspepsia in Hong Kong: role of open-access upper endoscopy

BACKGROUND

In the management of dyspepsia, upper endoscopy is an important component. In our locality, patients requiring upper endoscopy are conventionally referred to specialist clinics by family physicians. We have introduced the first open-access upper endoscopy service in Hong Kong, which has allowed family physicians to arrange endoscopy without prior specialist consultation. A study on the outcome of open-access upper endoscopy in contrast with the conventional referral system was conducted.

METHODS

For patients presenting with dyspepsia, family physicians in our region were given the option to arrange upper endoscopy directly with our Medical Endoscopy Unit in addition to the conventional referral to specialist clinics. The results were compared with those from the specialist clinic. A detailed prospective follow up was performed from June to September 1997 to evaluate the outcome and impact of open-access upper endoscopy.

RESULTS

From November 1996 to September 1999, 978 referrals for open-access upper endoscopy were received. The service significantly reduced the waiting time for the procedure by 16 weeks. Open-access upper endoscopy had similar detection rates for peptic ulcers and cancers compared with referrals from specialist clinics. Seventy-five percent of patients did not require further consultation with their family physicians within 2 months after endoscopy. It is a safe and effective procedure in establishing a definitive diagnosis. All family physicians were satisfied with the open-access upper endoscopy service.

CONCLUSIONS

This is the first Asian report on this service. Open-access upper endoscopy reduced waiting time from the patient perspective, decreased subsequent consultations with family physicians and reduced referral to specialist clinics as well as increased patient and doctor satisfaction. Both referral systems for endoscopy were similar in terms of the diagnostic yield.

Applying a prediction rule to identify low-risk patients with community-acquired pneumonia

STUDY OBJECTIVES

To study the validity of a recently developed community-acquired pneumonia (CAP) severity prediction rule in estimating mortality, to determine its utility in decision making regarding hospitalization, and to assess factors influencing this decision.

DESIGN

Retrospective chart review.

SETTING

Two sites of the University Health Network, the Toronto General and Toronto Western Hospitals, tertiary-care teaching institutions with a sizable primary-care and secondary-care source of referrals, and a total of 900 beds.

PATIENTS

Consecutive patients with CAP admitted between February and June 1996.

MEASUREMENTS AND RESULTS

A single trained medical records extractor assembled data to compare our population to that used in developing the CAP prediction rule, in terms of mortality and to assess reasons for hospitalization. Two hundred fifty-five eligible patients were admitted, and 244 charts (96%) were available. Our patients tended to be older, with nearly four times as many residents of chronic care institutions (39% compared with 10%), and had a higher risk class distribution than the published cohort. Risk class-specific mortality was similar in four of five classes. Of the 71 patients in the low-risk classes, 67 had additional reasons for admission; 18 of which were psychosocial (homelessness, substance abuse, or inadequate home supports).

CONCLUSIONS

The CAP severity prediction rule estimates mortality well. Admission of low-risk patients was linked to psychosocial and other medical reasons not captured by this rule. The rule can be very useful in assessing the need for hospitalization; however, there remains a significant percentage of patients with a low severity score who may require hospitalization for psychosocial and economic considerations.

(13)C-urea breath test without a test meal is highly accurate for the detection of Helicobacter pylori infection in Chinese

BACKGROUND

Conventional (13)C-urea breath testing ((13)C-UBT) includes a test meal to delay gastric emptying, which, theoretically, improves the accuracy of the test. Citric acid has been proposed as the best test meal. However, recent studies have suggested that a test meal may not be necessary.

AIM

To investigate a new (13)C-UBT protocol without a test meal in a Chinese population.

METHODS

Consecutive dyspeptic patients referred for upper endoscopy were recruited. (13)C-UBT was performed on two separate days with or without a test meal (2.4 Gm citric acid) and compared with the 'gold standard' (CLO test and histology).

RESULTS

Two hundred and two patients were tested. Using receiver operating characteristics (ROC) analysis, the optimal delta-value and optimal measurement interval for UBT were 5% and 30 min, respectively, both with or without a test meal. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of (13)C-UBT with citric acid (96.5%, 97.7%, 98.2%, 95.6%, 97.0%) were similar to (13)C-UBT without a test meal (94.7%, 97.7%, 98.2%, 93.5%, 96.0%).

CONCLUSION

This simplified (13)C-UBT protocol without a test meal produced highly accurate and reliable results in the Chinese population.

Supramolecular structure and nuclear targeting efficiency determine the enhancement of transfection by modified polylysines

Polylysine (pLy) has been used as a DNA carrier in nonviral gene delivery systems because it forms complexes with plasmid DNA via charge interaction, and condenses it into a compact structure. We have recently shown that cross-linking nuclear localization sequences (NLSs) to pLy can enhance transfection by conferring specific recognition by the cellular nuclear import 'receptor', the NLS-binding importin alpha/beta heterodimer. The present study examines and correlates for the first time the effect of the lysine/nucleotide (Ly/Nu) ratio on transfection, recognition by importin alpha/beta, and structure as determined using electron microscopy (EM) and atomic force microscopy (AFM), for pLy-DNA complexes with and without NLSs or mutant versions thereof. Intriguingly, we observed two distinct peaks of transfection enhancement at Ly/Nu ratios of 0.4 and 4.0, attributable to specific NLS recognition by importins and DNA compaction, respectively. The results indicate a clear correlation between the pLy-DNA structure, importin alpha/beta recognition, and gene transfer efficiency, thus underlining the importance of using pLy-DNA at the optimal Ly/Nu ratio.

Study of the hygroscopic properties of selected pharmaceutical aerosols using single particle levitation

PURPOSE

To use a single particle levitation technique to investigate the equilibrium water sorption characteristics in both the evaporation and growth of four respiratory drugs at 37 degrees C: atropine sulfate (AS), isoproterenol hydrochloride (IPHC) and isoproterenol hemisulfate (IPHS) and disodium cromoglycate (DSCG).

METHODS

The equilibrium water content was measured as a function of relative humidity (RH) by a single particle levitation technique using an electrodynamic balance (EDB). The change of water content was determined by the voltage required to balance the weight of the levitated particle electrostatically. The water activities of bulk samples were also measured. Growth ratios were determined and compared with values in the literature.

RESULTS

Crystallization or deliquescence was not observed for AS, IPHC and IPHS. The hysteresis in the water cycle was not observed for any of the drugs. At RH approximately 0%, AS particles still contain about 5% water but IPHC and IPHS particles do not contain any residual water. The aerodynamic growth ratio from RH 0% to 99.5% is 2.60, 2.86, 2.42 and 1.26 for AS, IPHC, IPHS and DSCG, respectively. Supersaturated droplets of IPHC and IPHS are expected to exist in the ambient conditions. DSCG is in a solid state in the RH range of 10-90%.

CONCLUSIONS

It is expected that some aerosolized drugs of low solubility may experience supersaturation before they enter the human body and this could exert a significant influence both on particle loss before inhalation and on the deposition of the drugs in the lungs. The EDB is a convenient and reliable tool for studying the hygroscopic properties of pharmaceutical aerosols, especially for supersaturated solutions.

Psychological functioning and quality of life in lung transplant candidates and recipients

OBJECTIVE

The purpose of this study was to examine the psychological functioning and quality of life (QOL) of lung transplant candidates and recipients.

METHODS

The following measures were completed by 36 lung transplant candidates (the pretransplant group [PRE]) and 73 recipients (the posttransplant group [POST]): the Rand-36 Item Health Survey 1.0 (RAND-36), visual analog scale of overall QOL (OQOL), Brief Symptoms Inventory (BSI), Derogatis Sexual Functioning Inventory (DSFI), Hospital Anxiety and Depression Scale (HAD), Rosenberg Self-Esteem Scale (RSES), and Body Cathexis Scale (BC).

RESULTS

Compared to the PRE, POST patients had significantly better scores on the following measures: RAND-36 total, physical health, role limitations due to physical health, general health, vitality, and social functioning subscales (all p < 0.0001); visual analog scale of OQOL (p < 0.0001); BSI (p < 0.05); BC (p < 0.05); HAD anxiety (p < 0.05) and depression (p < 0.0001); and RSES (p < 0.05). Despite better scores, some areas did not differ between the PRE and the POST, and many patients continued to experience impairments in psychological functioning. Specifically, the RAND-36 emotional health and role limitations due to emotional health subscale scores did not differ between the PRE and the POST and they remained lower than published norms. A significant proportion of patients in both groups (44% of PRE patients and 28% of POST patients) had borderline or clinical levels of anxiety (ie, the HAD). Finally, PRE and POST mean scores were significantly lower than published norms on the RSES (p < 0.05) and the body image scale of the DSFI (p < 0.05).

CONCLUSIONS

Although lung transplant recipients have better general, physical, and psychological health than their pretransplant counterparts, the present research suggests that both groups experience impairment in several areas of psychological functioning. Future research into the QOL of the lung transplant population should be aimed at recognizing, intervening, and improving patients' psychological and emotional well-being.

Symmetric heaping in grains: a phenomenological model

Heap formation of granular materials in a vertical vibrating bed is studied by a simple model using the profile of the heap as the dynamic variable. Vibration increases the local height, but is counterbalanced by the nonlinear coupling, which tends to suppress the growth of the height. The steady state heap can be solved in closed form in terms of Jacobian elliptic functions. Phenomena such as heap formation and downward and upward heaps can be reproduced. Our results agree with the experimentally observed change of downward to upward steady heaps as the vibration strength is increased. Predictions from the model compare favorably with experimental results on heap profiles and heaping angles.

Outcomes of patients with multidrug-resistant pulmonary tuberculosis treated with ofloxacin/levofloxacin-containing regimens

OBJECTIVE

To analyze outcomes of patients with multidrug-resistant tuberculosis (MDR-TB) treated with ofloxacin/levofloxacin-containing regimens.

MATERIALS AND METHODS

From February 1990 through June 1997, 63 MDR-TB patients (with bacillary resistance to at least isoniazid and rifampin in vitro) were analyzed retrospectively. Twenty-two patients (34.9%) had had no previous antituberculosis chemotherapy. Each patient received either ofloxacin (53) or levofloxacin (10) even though 13 patients had bacilli resistant to ofloxacin in vitro. The other accompanying drugs mainly included aminoglycosides, cycloserine, ethionamide/prothionamide, and pyrazinamide. Sputum smear and culture examinations for acid-fast bacilli (AFB) were performed monthly for the initial 6 months and then at 2- to 3-month intervals until the end of treatment. Comparison was made between clinical successes and failures using univariate and multiple logistic regression analyses for the following variables: age, sex, presence of cavitation, extent of disease, sputum smear positivity, in vitro resistance to ofloxacin, in vitro resistance to streptomycin and/or ethambutol, treatment adherence, and the number of drugs per regimen.

RESULTS

Fifty-one patients (81.0%) were cured, nine patients (14.3%) failed, and three patients (4.7%) died. For the entire group, the mean duration of treatment was 14.0 months, and the mean number of drugs was 4.7. Mean durations of chemotherapy in successful and failed patients were 14.5 and 14.2 months, respectively. Mean time for sputum smear and culture conversions were 1.7 and 2.1 months, respectively. Only cavitation, resistance to ofloxacin, and poor adherence were found to be variables independently associated with adverse outcomes (p < 0.05; odds ratios = 15.9, 13.5, 12.8, respectively). Negative sputum cultures after 2 and 3 months of therapy were 100% predictive of cure. Positive sputum cultures after 2 and 3 months were 52.3% and 84.6% predictive of failure, respectively. One patient (2.1%) relapsed after apparent cure. Twenty-five patients experienced adverse drug reactions, but only 12 of them needed drug modifications.

CONCLUSION

Most MDR-TB patients can be treated effectively with ofloxacin/levofloxacin-containing regimens. Presence of cavitation, resistance to ofloxacin in vitro, and poor adherence to therapy portend treatment failure. Monitoring monthly sputum culture for AFB in the initial months of chemotherapy helps predict clinical outcomes.

Osteoporosis and lung transplantation: a prospective study

STUDY OBJECTIVE

Osteoporosis is a well-recognized complication of lung transplantation that may significantly impair the quality of life of transplant recipients. We performed a prospective study of bone mineral density (BMD) before and after transplantation to determine the degree of bone mass loss associated with lung transplantation Patients and design: We conducted a prospective study of BMD in 28 patients with various end-stage respiratory diseases pretransplantation and 6 to 12 months posttransplantation. The BMD of the lumbar spine (LS) and femoral neck (FN) were measured. All 28 patients were treated only with vitamin D and calcium supplementation posttransplant. The primary endpoint was the percentage change in BMD. The secondary endpoint was the incidence of fractures posttransplant. A univariate analysis was conducted to determine the various risk factors associated with bone mass loss pretransplant and posttransplant.

RESULTS

Prior to transplantation, moderate to severe bone disease was evident. The mean (+/- SD) pretransplant T score (the number of SDs from the peak bone mass) and Z score (the number of SDs from the age-matched mean) for the LS were -1.72 +/- 1.37 and -1.44 +/- 1.31, respectively. The mean pretransplant T score and Z score for the FN were -2.65 +/- 1.01 and -1.5 +/- 1.43, respectively. Within 6 to 12 months posttransplant, the mean BMD for the LS decreased by 4.76% (p < 0.001), while the mean BMD for the FN decreased by 5.3% (p < 0.001). Five of the 28 patients (18%) suffered osteoporotic fractures posttransplant, while no fractures were documented pretransplant. The cumulative steroid dose posttransplant was associated with a drop in BMD for the LS and FN (r = 0.39, p = 0.039 and r = 0.63, p < 0.001, respectively), while a negative association was found between cumulative steroid use pretransplant and baseline LS and FN T scores (r = -0.4, p = 0. 02 and r = -0.43, p = 0.023, respectively).

CONCLUSION

Within 6 to 12 months after lung transplantation, there is a significant decrease in BMD at both the LS and FN levels (approximately 5%) despite vitamin D and calcium supplementation. This drop in BMD is associated with a relatively high incidence of osteoporotic fractures posttransplant.

Verbal fluency in schizophrenia: reduction in semantic store

OBJECTIVE

This is a study of the word production of patients with schizophrenia using a semantic verbal fluency task to address the unresolved issue of retrieval or storage impairment.

METHOD

Twenty-one patients with schizophrenia and 11 matched healthy subjects performed a semantic verbal fluency task on 'food', 'animal' and 'transport' categories in Cantonese for 3 minutes each on five separate trials.

RESULTS

Patients generated significantly fewer numbers of words compared with control on each trial. The estimated lexicon size of the patients was significantly smaller than that of the equivalent group. The amount of shared words and variable words generated in all five trials were reduced in the patient group.

CONCLUSIONS

Our results suggest that poor verbal fluency in patients with schizophrenia may partly be attributable to reduction in semantic store. The importance of temporal lobe involvement on verbal fluency deficits needs to be emphasised as an integral part of the neurobiological basis of schizophrenia research.

Lung cancer mortality among a cohort of men in a silicotic register

To examine any association between silicosis and lung cancer, the clinic records of a cohort of 1502 silicotic workers diagnosed after 1981 were reviewed. All of the essential data, including occupational exposure, smoking habits, radiographic extent of silicosis, and vital status of each subject, were noted. The standardized mortality ratio for various causes of death was calculated. Thirty-three patients died from lung cancer, giving a standardized mortality ratio of 1.94 (95% confidence interval, 1.35 to 2.70). However, smoking accounted for most of the excess of lung cancer deaths among the silicotic workers in the cohort, and no consistent relationship between lung cancer mortality risk and either duration of exposure to silica dust or severity of silicosis was observed. There is no conclusive evidence in our data to support the hypothesis that lung cancer may be associated with silicosis.