[Historical review of schistosomiasis prevention and treatment in southern Anhui from 1950 to 1970]

From 1950 to 1970, under the leadership of the central government, workstations for the prevention and control of schistosomiasis were established in the southern Anhui region. In terms of controlling the source of the disease, light and severe epidemic areas were scientifically divided. By opening new ditches to replace old ones, changing paddy fields to dry fields, and using traditional Chinese medicine and Western medicine to prevent the intermediate host of schistosomiasis, oncomelania from surviving. By managing the feces from human and animals and controlling the water source, the transmission route of schistosome eggs has been effectively cut off. At the same time, the education of hygiene awareness among susceptible populations were strengthened. In terms of diagnosis, modern physical and biochemical detection were used to improve the accuracy of diagnosis. In terms of treatment, by combining traditional Chinese medicine and Western medicine, together with the splenectomy, the cure rates were improved. In the process of preventing and controlling schistosomiasis, the governments of Anhui Province and the southern region of Anhui Province achieved good results, providing useful reference for the prevention and control of other diseases.

[Comparison of the effects and safety of dydrogesterone and medroxyprogesterone acetate on endometrial hyperplasia without atypia: a randomized controlled non-inferior phase Ⅲ clinical study]

Objective: To compare the effects and safety of dydrogesterone (DG) and medroxyprogesterone acetate (MPA) on the treatment in patients with endometrial hyperplasia without atypia (EH). Methods: This was a single-center, open-label, prospective non-inferior randomized controlled phase Ⅲ trial. From February 2019 to November 2021, patients with EH admitted to the Obstetrics and Gynecology Hospital of Fudan University were recruited. Enrolled patients were stratified according to the pathological types of simple hyperplasia (SH) or complex hyperplasia (CH), and were randomised to receive MPA or DG. Untill May 14, 2022, the median follow-up time after complete response (CR) was 9.3 months (1.1-17.2 months). The primary endpoint was the 6-month CR rate (6m-CR rate). The secondary endpoints included the 3-month CR rate (3m-CR rate), adverse events rate, recurrence rate, and pregnancy rate in one year after CR. Results: (1) A total of 292 patients with EH were enrolled in the study with the median age of 39 years (31-45 years). A total of 135 SH patients were randomly assigned to MPA group (n=67) and DG group (n=68), and 157 CH patients were randomly assigned to MPA group (n=79) and DG group (n=78). (2) Among 292 patients, 205 patients enrolled into the primary endpoint analysis, including 92 SH patients and 113 CH patients, with 100 patients in MPA group and 105 in DG group, respectively. The 6m-CR rate of MPA group and DG group were 90.0% (90/100) and 88.6% (93/105) respectively, and there were no statistical significance (χ²=0.11, P=0.741), with the rate difference (RD) was -1.4% (95%CI:-9.9%-7.0%). Stratified by the pathology types, the 6m-CR rate of SH patients was 93.5% (86/92), and MPA group and DG group were respectively 91.1% (41/45) and 95.7% (45/47); and the 6m-CR rate of CH patients was 85.8% (97/113), and MPA group and DG group were 89.1% (49/55) and 82.8% (48/58) respectively. The 6m-CR rates of the two treatments had no statistical significance either (all P>0.05). A total of 194 EH patients enrolled into the secondary endpoint analysis, including 88 SH patients and 106 CH patients, and 96 patients in MPA group and 98 in DG group, respectively. The 3m-CR rate of SH patients were 87.5% (77/88), while the 3m-CR rates of MPA group and DG group were 90.7% (39/43) and 84.4% (38/45), respectively; the 3m-CR rate of CH patients was 66.0% (70/106), and MPA group and DG group had the same 3m-CR rate of 66.0% (35/53). No statistical significance was found between the two treatments both in SH and CH patients (all P>0.05). (3) The incidence of adverse events between MPA group and DG group had no statistical significance (P>0.05). (4) A total of 93 SH patients achieved CR, and the cumulative recurrence rate in one year after CR were 5.9% and 0 in MPA group and DG group, respectively. While 112 CH patients achieved CR, and the cumulative recurrence rate in one year after CR were 8.8% and 6.5% in MPA group and DG group, respectively. There were no statistical significance between two treatment groups (all P>0.05). Among the 93 SH patients, 10 patients had family planning but no pregnancy happened during the follow-up period. Among the 112 CH patients, 21 were actively preparing for pregnancy, and the pregnancy rate and live-birth rate in one year after CR in MPA group were 7/9 and 2/7, while in DG group were respectively 4/12 and 2/4, and there were no statistical significance in pregnancy rate and live-birth rate between the two treatment groups (all P>0.05). Conclusions: Compared with MPA, DG is of good efficacy and safety in treating EH. DG is a favorable alternative treatment for EH patients.

[Mechanism of intestinal injury induced by WNT2B high-expressed fibroblasts in Crohn's disease]

Objective: To explore the mechanism of intestinal tissue damage induced by macrophages activated by WNT2B high-expressed fibroblasts. Methods: This study involved biological information analysis, pathological tissue research and cell experimental research. The biological information of the colon tissue from the children with inflammatory bowel disease in previous study was analyzed again with single-cell sequencing. The pathological tissues were collected by colonoscopy from 10 children with Crohn's disease treated in the Department of Gastroenterology of Guangzhou Women and Children's Medical Center from July 2022 to September 2022. According to the findings of colonoscopy, tissues with obvious inflammation or ulceration were classified as the inflammatory group, while tissues with slight inflammation and no ulceration were classified as the non-inflammatory group. HE staining was performed to observe the pathological changes of the colon tissues. Macrophage infiltration and CXCL12 expression were detected by immunofluorescence. In terms of cell experiments, fibroblasts transfected with WNT2B plasmid or empty plasmid were co-cultured with salinomycin treated or non-treated macrophages, respectively; the expression of proteins through Wnt classical pathway were detected by western blotting. Macrophages treated with SKL2001 were used as the experimental group, and those with phosphate buffer as the control group. The expression and secretion of CXCL12 in macrophages were detected by quantitative Real-time PCR and enzyme-linked immunosorbent assay (ELISA). T-test or rank sum test were used for the comparison between groups. Results: Single-cell sequencing analysis suggested that macrophages were the main cells in inflammatory bowel disease colon tissue, and there was interaction between WNT2B high-expressed fibroblasts and macrophages. HE staining of the 10 patients ((9.3±3.8) years old, 7 males and 3 females) showed that the pathological score of colon tissue in the inflammatory group was higher than that in the non-inflammatory group (4 (3, 4) vs. 2 (1, 2) points, Z=3.05, P=0.002). Tissue immunofluorescence indicated that the number of infiltrating macrophages in the inflammatory group was significantly higher than that in the non-inflammatory group under high power field of view (72.8±10.4 vs.8.4±3.5, t=25.10, P<0.001), as well as the number of cells expressing CXCL12 (14.0±3.5 vs. 4.7±1.9, t=14.68, P<0.001). In cell experiments, western blotting suggested an elevated level of glycogen synthase kinase-3β phosphorylation in macrophages co-cultured with fibroblast transfected with WNT2B plasmid, and salinmycin could reverse this change. Real-time PCR suggested that the transcription level of CXCL12 in the experimental group was higher than that in the control group (6.42±0.04 vs. 1.00±0.03, t=183.00, P<0.001), as well as the expression and secretion of CXCL12 by ELISA ((465±34) vs. (77±9) ng/L, t=13.21, P=0.006). Conclusion: WNT2B high-expressed fibroblasts can secrete WNT2B protein and activate the Wnt classical signaling pathway thus enhancing the expression and secretion of CXCL12 in macrophages, inducing the development of intestinal inflammation of Crohn's disease.

[A death case of oral lime sulfur mixture poisoning]

The Second Affiliated Hospital of Shandong First Medical University treated a patient with oral sulfur mixture poisoning on January 14, 2020. The patient presented with cyanosis and disturbance of consciousness as the first manifestations, accompanied by metabolic acidosis, shock, hypercalcemia and severe liver function and myocardial damage. The patient was given active treatment, including gastric lavage, blood purification, methylene blue application, correction of shock, organ support and other therapies. However the treatment was poor. Finally, the patient's family chose to give up and requested to be discharged from the hospital, and the patient died on the same day after follow-up.

[Clinical characteristics of heart failure with recovered ejection fraction]

Objective: To summarize the clinical characteristics of heart failure patients with recovered ejection fraction (HFrecEF) and identify variables capable of predicting left ventricular ejection fraction (LVEF) recovery. Methods: This case control study included patients with heart failure, who admitted to Department of Cardiology of Beijing Hospital from January 1, 2009 to December 31, 2017. The patients were divided into 3 groups based on the baseline LVEF and changes of LVEF: heart failure with reduced ejection fraction (HFrEF, baseline LVEF≤40%, follow-up LVEF≤40% or follow-up LVEF>40% but LVEF increase<10% from baseline), HFrecEF(baseline LVEF≤40%, follow-up LVEF>40% and increase≥10% from baseline), and heart failure with preserved ejection fraction (HFpEF, baseline LVEF>40%). Clinical data were collected and endpoint events (all-cause death, cardiovascular death and sudden death) were recorded. The Log-rank test was used to evaluate the differences of terminal events in different groups, and Kaplan-Meier survival analysis was performed. Logistic regression equation was used to identify prognostic factors of HFrecEF. Results: A total of 310 patients with heart failure were included. There were 91(29.4%) HFrEF patients, 38(12.3%) HFrecEF patients and 181(58.4%) HFpEF patients. Compared with HFrEF patients and HFpEF patients, HFrecEF patients were featured by younger age, more likely to be female, higher systolic blood pressure, diastolic blood pressure and resting heart rate (all P<0.05). Dilated cardiomyopathies were more common, while old myocardial infarctions were less common in HFrecEF (both P<0.05). During a median follow-up of 36.7(18.0, 63.9) months, Kaplan-Meier survival analysis found that HFrecEF patients had the lowest all-cause mortality (Log-rank P=0.047, HFrecEF vs. HFpEF P=0.017, HFrecEF vs. HFrEF P=0.016, and HFpEF vs. HFrEF P=0.782).The cardiovascular mortality ranged from low to high was in HFrecEF patients, HFpEF patients, and HFrEF patients (Log-rank P<0.001, HFrecEF vs. HFpEF P=0.029, HFrecEF vs. HFrEF P<0.001, HFrEF vs. HFpEF P=0.005). Sudden death rate was similar among the three groups (Log-rank P=0.520). Logistic regression analysis showed that left ventricular end-diastolic diameter (LVEDD)≤55 mm (OR=5.922, 95%CI 1.685-20.812, P=0.006), higher diastolic blood pressure (OR=1.058, 95%CI 1.017-1.100, P=0.005), faster resting heart rate (OR=1.042, 95%CI 1.006-1.080, P=0.024), absence of old myocardial infarction (OR=5.343, 95%CI 1.731-16.488, P=0.004) were independent prognostic factors of LVEF recovery after clinical treatment. Conclusions: Patients with HFrecEF are associated with a better prognosis as compared to patients with HFrEF and HFpEF. LVEDD≤55 mm, higher diastolic blood pressure, faster heart rate,and absence of old myocardial infarction are independent prognostic factors of LVEF recovery after clinical treatment.

A new species of the Asian leaf litter toad genus Leptobrachella Smith, 1925 (Anura, Megophryidae) from northwest Guizhou Province, China

A new species of the Asian leaf litter toad genus Leptobrachella is described from Guizhou Province, China. Molecular phylogenetic analyses support the new species as an independent lineage deeply nested in the Leptobrachella clade. The new species is distinguished from its congeners by a combination of the following morphological characters: body size medium (SVL 29.7–31.2 mm in five adult males); dorsal skin shagreened, some of the granules forming longitudinal short skin ridges; tympanum distinctly discernible, slightly concave; supra-axillary, femoral, pectoral and ventrolateral glands distinctly visible; absence of webbing and lateral fringes on fingers; toes with narrow lateral fringes but without webbing; heels overlapping when thighs are positioned at right angles to the body; tibia-tarsal articulation reaching the middle of eye when leg stretched forward. The discovery highlighted the underestimated species diversity in the Leptobrachella toads in southwestern China.

[The discussion of the correlation between tumor necrosis factor-alpha and aquaporin 4 expression in critical poisoning brain edema]

Critical poisoning is a critical illness. Cerebral edema after poisoning is one of the important factors that cause the patient's condition to worsen and affect the prognosis of patients after acute brain injury. Aquaporin 4 (AQP-4) is an important member of the aquaporin family and is abundantly expressed in the central nervous system, playing a pivotal role in the formation of cerebral edema. Brain injury can cause the secretion of inflammatory transmitters, causing or aggravating cerebral edema. Tumor necrosis factor-alpha (TNF-α) has been confirmed to be most closely related to cerebral edema, and can participate in the formation and development of brain edema by regulating AQP-4.

[Investigation on the awareness of snoring hazard and prevalence of obstructive sleep apnea among civil servants]

Objective: To investigate the awareness of snoring hazard and prevalence of obstructive sleep apnea (OSA) among civil servants. Methods: A cross-sectional survey was conducted to investigate the awareness of snoring hazards among in-service civil servants who had annual medical examination in a Guangdong provincial institution from September to November 2017. The high-risk group for OSA was screened and diagnosed by sleep monitoring. Results: 1 036 of 1 241 civil servants were enrolled in the study for integral data. 60.1% (623/1 036) of the subjects realized that snoring was harmful to health. The most common source to develop OSA awareness was network (59.6%, 371/623), followed by television (48.0%), relatives and friends (46.6%), newspaper (44.5%) and radio (18.9%). The awareness rate of snoring consequences was as follows: decreased sleep quality (71.9%, 448/623), sudden death (52.2%), daytime sleepiness (44.3%), cardiovascular and cerebrovascular diseases (42.9%), hypertension (24.4%) and sexual dysfunction (16.7%). 22.0% (228 / 1 036) of the cases were classified into high-risk OSA. The prevalence of OSA among high-risk group was 46.05%(105/228)and only 0.9% (2/228) of them had been diagnosed with OSA. Conclusion: Civil servants had awareness of snoring hazard to a certain extent. Among civil servants classified into high-risk OSA, the OSA perveance was high but the rate of diagnosis and treatment was very low.

A new species of the Music frog Nidirana (Anura, Ranidae) from Guizhou Province, China

The Music frog genus Nidirana is widely distributed in East and South Asia. Here, a new species of the genus is described from southwestern China. Phylogenetic analyses based on the mitochondrial 16S rRNA and COI gene sequences supported the new species as a clade closely related to N. leishanensis, N. hainanensis, N. chapaensis, N. daunchina, and N. yaoica. The new species could be distinguished from its congeners by a combination of the following characters: body of medium size (SVL 41.2-43.5 mm in males and 44.7 mm in female); lateroventral groove only present on toes; relative finger lengths: II < IV < I < III; three metatarsal tubercles on palm; heels overlapping when hindlimbs flexed at right angles to axis of body; tibiotarsal articulation reaching the level of eye when leg stretched forward; a pair of subgular internal vocal sacs at corners of throat in male; nuptial pad present on the inner side of base of fingers I in breeding male; tadpole labial tooth row formula with 1:1+1/1+1:2; in males, the advertisement call contains two kinds of notes and one call contains 2-6 repeated regular notes.

[Citrate anticoagulation hemoperfusion in the treatment of 273 patients]

Early hemoperfusion in poisoned patients can remove poisons rapidly and effectively, which plays an important role in improving the prognosis of patients. The key of hemoperfusion therapy is the safe and effective anticoagulation. The local citrate anticoagulation effect acid is good, it also has little effect on the systemic coagulation mechanism and internal environment of patients, so it is worthy of promotion. We retrospectively analyzed the clinical data and treatment of 273 patients who were poisoned by citrate anticoagulant in the emergency intensive care unit of the Second Affiliated Hospital of Shandong First Medical University, aiming at perfusion of citrate anticoagulant in patients with poisoning. Provide a certain clinical reference.

[Structural equation model analysis of infectious disease-specific health literacy scale in China]

Objective: To explore the relationship between different dimensions of infectious disease-specific health literacy scale in China. Methods: Structural equation model (SEM) was employed to assess the psychometric properties of the infectious disease-specific health literacy scale. Based on the database from a randomly selected sample of 4 499 adult residents in three provinces in China, from March to May 2015. AMOS 21.0 software was used to build the SEM for data analyses. Results: SEM analyses showed a good model fit of data, with the following satisfied parameters: goodness-of-fit index was 0.969, adjusted goodness-of-fit index was 0.962, root mean square residual was 0.038, root mean square error of approximation was 0.038, standardized root mean square residual was 0.032, Tacker-Lewis index/non-normed fit index was 0.926, comparative fit index was 0.934, normed fit index was 0.925, relative fit index was 0.915, incremental fit index was 0.934, parsimony goodness-of-fit index was 0.782, parsimony-adjusted normed fit index was 0.817, parsimony-adjusted comparative fit index was 0.825 and critical N was 702. The established SEM showed that the total influence path coefficient of "infectious disease-related knowledge and values" on the "infectious disease prevention" , "management or treatment of infectious diseases" and "identification of infection sources" were 0.771, 0.744 and 0.843, respectively. The total influence path coefficients of "identification of infection sources" , "infectious disease prevention" on "management or treatment of infectious diseases" were 0.164 and 0.535, respectively. The effect of "infectious disease-related knowledge and values" on "management or treatment of infectious diseases" appeared the greatest (55.4%), followed by "infectious disease prevention" (28.6%) and "identification of infection sources" (2.7%). Conclusion: This SEM could be optimistically used for planning and evaluation of health education and promotion programs on infectious diseases prevention.

[Clinical effect of combined artificial extracorporeal liver support therapy for toxic hepatic failure]

Objective: To investigate the clinical effect of plasma exchange (PE) versus double plasma molecular adsorption system combined with PE (DPMAS+PE) in the treatment of toxic hepatic failure. Methods: A total of 67 patients with toxic hepatic failure who were admitted during the same period of time were divided into PE group, DPMAS+ PE group, and control group. The 22 patients in the PE group were treated with PE alone, and the 24 patients in the DPMAS+PE group were given DPMAS combined with PE. The clinical out-come was compared between the three groups. Results: Both treatment groups had significantly higher clinical response rate and 24-week survival rate than the control group. After treatment, both treatment groups had significant reductions in the serum levels of total bilirubin (TBil) , direct bilirubin (DBil) , alanine aminotransfer-ase (ALT) , and aspartate aminotransferase (AST) , and the PE group had significant reductions in the albumin (Alb) level and activated partial thromboplastin time (APTT) (P<0.05) ; the DPMAS+PE group showed no sig-nificant changes in the Alb level and APTT (P>0.05). There were no significant differences in TBil, DBil, ALT, and AST between the two treatment groups after treatment (P>0.05). After treatment, the PE group had significantly higher Alb level and APTT than the DPMAS + PE group (P<0.05). Compared with the control group, both treatment groups had significant reductions in TBil, DBil, ALT and AST after treatment (P<0.05). Conclusion: The two artificial liver support techniques can significantly improve patients' liver function and in-crease their survival rate, and the combined artificial liver support technique can reduce the amount of plasma used.

Computational modeling of intraocular gas dynamics

The purpose of this study was to develop a computational model to simulate the dynamics of intraocular gas behavior in pneumatic retinopexy (PR) procedure. The presented model predicted intraocular gas volume at any time and determined the tolerance angle within which a patient can maneuver and still gas completely covers the tear(s). Computational fluid dynamics calculations were conducted to describe PR procedure. The geometrical model was constructed based on the rabbit and human eye dimensions. SF6 in the form of pure and diluted with air was considered as the injected gas. The presented results indicated that the composition of the injected gas affected the gas absorption rate and gas volume. After injection of pure SF6, the bubble expanded to 2.3 times of its initial volume during the first 23 h, but when diluted SF6 was used, no significant expansion was observed. Also, head positioning for the treatment of retinal tear influenced the rate of gas absorption. Moreover, the determined tolerance angle depended on the bubble and tear size. More bubble expansion and smaller retinal tear caused greater tolerance angle. For example, after 23 h, for the tear size of 2 mm the tolerance angle of using pure SF6 is 1.4 times more than that of using diluted SF6 with 80% air. Composition of the injected gas and conditions of the tear in PR may dramatically affect the gas absorption rate and gas volume. Quantifying these effects helps to predict the tolerance angle and improve treatment efficiency.

Diversity and antimicrobial activity of culturable endophytic fungi isolated from moso bamboo seeds

Bamboos, regarded as therapeutic agents in ethnomedicine, have been used to inhibit inflammation and enhance natural immunity for a long time in Asia, and there are many bamboo associated fungi with medical and edible value. In the present study, a total of 350 fungal strains were isolated from the uncommon moso bamboo (Phyllostachys edulis) seeds for the first time. The molecular diversity of these endophytic fungi was investigated and bioactive compound producers were screened for the first time. All the fungal endophytes were categorized into 69 morphotypes according to culturable characteristics and their internal transcriber spacer (ITS) regions were analyzed by BLAST search with the NCBI database. The fungal isolates showed high diversity and were divided in Ascomycota (98.0%) and Basidiomycota (2.0%), including at least 19 genera in nine orders. Four particular genera were considered to be newly recorded bambusicolous fungi, including Leptosphaerulina, Simplicillium, Sebacina and an unknown genus in Basidiomycetes. Furthermore, inhibitory effects against clinical pathogens and phytopathogens were screened preliminarily and strains B09 (Cladosporium sp.), B34 (Curvularia sp.), B35 (undefined genus 1), B38 (Penicillium sp.) and zzz816 (Shiraia sp.) displayed broad-spectrum activity against clinical bacteria and yeasts by the agar diffusion method. The crude extracts of isolates B09, B34, B35, B38 and zzz816 under submerged fermentation, also demonstrated various levels of bioactivities against bambusicolous pathogenic fungi. This study is the first report on the antimicrobial activity of endophytic fungi associated with moso bamboo seeds, and the results show that they could be exploited as a potential source of bioactive compounds and plant defense activators. In addition, it is the first time that strains of Shiraia sp. have been isolated and cultured from moso bamboo seeds, and one of them (zzz816) could produce hypocrellin A at high yield, which is significantly different from the other strains published.

Handwashing behaviour among Chinese adults: a cross-sectional study in five provinces

OBJECTIVES

To describe the patterns of handwashing behaviour among Chinese adults, and assess their associations with sociodemographic factors and knowledge of hand hygiene.

STUDY DESIGN

A representative sample (n = 6159) of Chinese adults aged 18-60 years in five provinces was attained by multiple-stage, stratified sampling mainly based on geographical location and economic status. Data on handwashing behaviour, knowledge of hand hygiene and sociodemographic factors were collected through self-administrated questionnaires.

METHODS

Associations between handwashing behaviour and sociodemographic factors were tested in logistic models. Path analysis was applied to examine the associations between sociodemographic factors, knowledge of hand hygiene and proper handwashing behaviour in order to evaluate the relative magnitude of these determinants and internal relationships.

RESULTS

This study found that 52.7% (rural vs urban: 44.6% vs 56.8%) and 67.3% (rural vs urban: 59.7% vs 71.1%) of Chinese adults reported they always washed hands before eating and after defaecation, and 30.0% (rural vs urban: 25.1% vs 32.8%) of adults always used soap or other sanitizers during washing. Using the criteria of 'always or very often washing hands with soap before eating and after defaecation without sharing a towel with family members after washing', only 47.2% (rural vs urban: 23.8% vs 59.1%) of the adults were graded to practice proper handwashing behaviour. Urban area, high level of education level, high level of knowledge about diseases, female gender and older age were protective factors for good hand hygiene; of these, area was found to be associated most strongly with handwashing behaviour.

CONCLUSIONS

Adherence to an appropriate handwashing method and duration of handwashing are critical problems among Chinese adults. Area difference, level of education and level of knowledge of hand hygiene were most strongly associated with handwashing behaviour, and should be targeted in future health education.

Enhanced Microwave Absorption Properties of Intrinsically Core/shell Structured La(0.6)Sr(0.4)MnO(3) Nanoparticles

The intrinsically core/shell structured La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores have been prepared. The magnetic, dielectric and microwave absorption properties are investigated in the frequency range from 1 to 12 GHz. An optimal reflection loss of -41.1 dB is reached at 8.2 GHz with a matching thickness of 2.2 mm, the bandwidth with a reflection loss less than -10 dB is obtained in the 5.5-11.3 GHz range for absorber thicknesses of 1.5-2.5 mm. The excellent microwave absorption properties are a consequence of the better electromagnetic matching due to the existence of the protective amorphous shells, the ferromagnetic cores, as well as the particular core/shell microstructure. As a result, the La(0.6)Sr(0.4)MnO(3) nanoparticles with amorphous shells and ferromagnetic cores may become attractive candidates for the new types of electromagnetic wave absorption materials. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11671-009-9374-y) contains supplementary material, which is available to authorized users.

The potential of Pseudozyma yeastlike epiphytes for the production of heterologous recombinant proteins

Although Basidiomycetes represent the most evolved class of fungi, they have been neglected with regard to recombinant gene expression. In this work, basidiomycetous yeasts belonging to Pseudozyma spp. were studied with respect to their amenability to heterologous protein production. Single plasmid or cotransformation experiments routinely afforded 100 to 200 independent transformants for the two tested species of Pseudozyma. Green fluorescent protein (GFP) was expressed in the correctly folded conformation, as demonstrated by fluorescence microscopy, and hen egg white lysozyme (HEWL) was expressed in its active form, as revealed by its lytic activity on Micrococcus lysodeikticus cells. Protease analysis established that Pseudozyma spp. contained equivalent or less extracellular protease activity than yeasts and far less protease activity than ascomycetous filamentous fungi in similar culture conditions. This proteolytic activity was inhibited by over 97% with a combination of PMSF and Pepstatin A. N-glycosylation patterns of native Pseudozyma flocculosa secreted proteins were comprised of one or a few short glycan chains that possess a classic eukaryotic structure typical of higher fungi and animal cells. This is the first report of a Basidiomycete that possesses multiple intrinsic characteristics necessary for use as a heterologous gene expression system.

Solitary fibrous tumors of the pleura: clinical, radiological, surgical and pathological evaluation

AIMS

To report a clinicopathological series of cases of solitary fibrous tumor of the pleura from Taiwan.

METHODS

Clinical data was collected from a review of medical records and telephone interviewing for follow-up.

RESULTS

Eight patients, three men and five women aging from 34 to 71 years, underwent tumor resection and were followed in a period from 7 months to 13.5 years. Six patients underwent standard thoracotomy and two had VATS for tumor excision. Tumors were pathologically benign in seven patients and malignant in one. Patients were all alive with no evidence of tumor recurrence at the time of this report.

CONCLUSIONS

One should always consider SFTPs as potentially malignant tumors. Complete resection remains the mainstay of cure. Standard thoracotomy should always be considered when a high suspicion of malignancy is raised, whereas VATS may be a preferred approach for smaller tumors.

Establishment of a gene transfer system for Pseudozyma flocculosa, an antagonistic fungus of powdery mildew fungi

A reliable DNA-mediated transformation system has been developed for Pseudozyma flocculosa, a fungus that is antagonistic to powdery-mildew fungi. Plasmids harboring various selectable markers under the control of different promoters were tested. Molecular analyses demonstrated that successful transformation could be achieved using a plasmid that confers resistance to hygromycin B under the control of the Ustilago maydis hsp70 promoter and terminator sequences. On average, 1-40 (mean = 20) transformants were obtained per 10 microg of linearized DNA per 10(8) protoplasts. Southern analysis of the transformants revealed that, in each case, the vector had integrated in multiple tandem copies into the genome of P. flocculosa, and that integration events were random. Pulsed-field gel electrophoresis was employed to separate the genome of P. flocculosa into at least 11 chromosomes with sizes ranging from 0.55 Mb to 2.9 Mb. Hybridization with the plasmid indicated that integration of vector DNA had occurred in one to several chromosomes depending on the transformant examined.

Diffuse leiomyomatosis of the esophagus

BACKGROUND

Leiomyomas are rare esophagus neoplasms. They are usually solitary, and the diffuse lesion is extremely rare.

CASE REPORT

A 19-year-old male presented with a 3-year history of occasional dysphagia and postprandial regurgitation. The chest radiographs showed a huge mass in the posterior mediastinum. Barium esophagograms showed narrowing of the middle third esophagus with proximal dilatation. The fibroesophagoscopy demonstrated multiple submucosal nodules below a level 22 cm from the incisor and covered with intact mucosa. CT scans of the chest showed a long segment of circumferential soft tissue in the posterior mediastinum which encircled and involved the upper two thirds of the esophagus. An intrathoracic esophagectomy with cervical esophagogastrostomy via the substernal route was performed. Grossly, multiple confluent myomatous nodules circumferentially involved the upper and middle third of the esophagus. Histologic findings showed diffuse leiomyomatosis of the esophagus.

CONCLUSION

Esophageal leiomyomatosis should be considered in a young patient with long-standing dysphagia in whom smooth, tapered esophageal narrowing on barium study and circumferential esophageal wall thickening on CT scan are seen. An esophagectomy combined with a reconstruction procedure is indicated.

Urea reduction ratio that considers effects of ultrafiltration and intradialytic urea generation

We modified the urea reduction ratio (URR) equation to correct the effects of ultrafiltration and intradialytic urea generation on the delivered dose of hemodialysis: mURR = [1 - (R/1 + 2*UF/BW) + 0.01*t] x 100% where mURR is modified URR, R is postdialysis plasma urea nitrogen (PUN) to predialysis PUN ratio, UF is ultrafiltrate volume in liters, BW is postdialysis body weight in kilograms, and t is dialysis session length in hours. The equation was validated against 145 hemodialysis treatments on 33 stable maintenance dialysis patients. The mURR values obtained closely predicted single-pool Kt/V (spKt/V) values. In contrast to conventional URR, the range of spKt/V values at each mURR value is narrow over a wide range of UF, t, and R values. Based on the mURR equation, mURR values of 64%, 70%, and 76% are mathematically equivalent to spKt/V levels of 1.0, 1.2, and 1.4, respectively. This equation can be a useful bedside tool to quantify hemodialysis dose.

Stability of urea and creatinine in spent hemodialysate

Urea and creatinine levels in spent hemodialysates showed only small declines in spite of incubation at 37 degrees C for 36 hours. In the determination of dialysate-side solute removal, it would seem prudent to keep spent dialysate cold during collection to retard bacterial breakdown of these waste products.

Hemangiopericytoma of the pleura causing massive hemothorax

Hemangiopericytoma is an unusual soft tissue tumor. A 54-year-old man presented with sudden onset of chest pain and dyspnea for 1 day. The initial chest x-ray showed a massive left pleural effusion. A contrast-enhanced computed tomographic scan of the chest showed a homogenously enhanced mass in the intrathoracic extrapulmonary space. A tube thoracostomy was performed and hemothorax was confirmed. A posterolateral thoracotomy was performed and a tumor in the parietal pleura of the left chest wall was resected. Grossly, the resected tumor arose from the parietal pleura, and the cut surface was elastic, soft, and pale yellow. There were several cystic formations and hemorrhages. Based on histologic findings, hemangiopericytoma with lower grade malignancy was diagnosed. The patient was alive and free from tumor recurrence 1 year after surgery. Intrathoracic extrapulmonary hemangiopericytoma is extremely rare, and surgical excision is the treatment of choice. Adjuvant chemotherapy or radiotherapy is indicated because of the high risk of recurrence and potential malignancy.

Haemopneumothorax from congenital cystic adenomatoid malformation in a cryptorchidism patient

Congenital cystic adenomatoid malformation (CCAM) of the lung is an uncommon congenital anomaly, especially in young adults. This study reports an 18-yr-old male with CCAM involving the right upper lobe, who presented with a moderate spontaneous haemopneumothorax initially. The patient also had bilateral abdominal cryptorchidism which required surgical treatment earlier in childhood. The chest radiographs and contrast-enhanced computed tomographic scan of the chest showed a multicystic lesion with air-fluid levels in the right upper lung. The right upper lobe was resected through a posterolateral thoracotomy. Histological examination confirmed the diagnosis of CCAM. To the authors' knowledge, congenital cystic adenomatoid malformation presenting with spontaneous haemopneumothorax and haemoptysis has never been described in the literature.

The pilH gene encodes an ABC transporter homologue required for type IV pilus biogenesis and social gliding motility in Myxococcus xanthus

Type IV pilus genes have been shown to be required for social gliding motility in Myxococcus xanthus. We report the discovery of four additional pil genes: pilD, a homologue of type IV prepilin leader peptidases; and pilG, pilH and pilI, which have no known homologues in other type IV pilus systems. pilH encodes an ATP-binding cassette (ABC) transporter homologue, the first such homologue to be required for the biogenesis of any bacterial pilus type. pilG and pilI are co-transcribed with pilH and appear to be functionally related to pilH. Null mutants of pilG, pilH and pilI all lack social motility, are deficient in pilus production, have elevated sporulation efficiencies and display similar developmental abnormalities. In addition, all three mutations reduced the amount of PilA found in the supernatant after cells were sedimented from liquid culture. We suggest that the products of these three genes form a single ABC exporter complex, in which pilI is an integral membrane protein with membrane-spanning domains, and pilG is an accessory factor. The complex may participate in pilus assembly and/or the export of PilA pilin.

Determination of the solute removal index for urea by using a partial spent dialysate collection method

In 22 hemodialysis patients, during a dialysis session, the solute removal index (SRI) for urea obtained from the use of a partial spent dialysate collection method was compared with that derived from the use of a total spent dialysate collection technique. The partial spent dialysate collection method was used to harvest a small representative sample of the total spent dialysate. The volumes of spent dialysate collected by the partial and the total spent dialysate collection methods were 1.7 +/- 0.4 L and 129.6 +/- 15.3 L, respectively. The total amount of urea nitrogen removed by dialysis as estimated by the partial spent dialysate collection method was similar to that determined by the total spent dialysate collection approach. As a result, the SRI value for urea obtained by the partial spent dialysate collection method (namely, 63% +/- 8%) correlated very well (r = 0.95, P < 0.001) with that derived by the total spent dialysate collection technique (namely, 62% +/- 8%). Our data suggest that it is feasible to use a simple partial spent dialysate collection method to obtain SRI results in patients treated with hemodialysis.

Acid-base values of single pass, batch system, bicarbonate based hemodialysate

The bicarbonate, calcium, and magnesium values of a single pass, batch system, bicarbonate based hemodialysate were found to be stable during a period of 5 hours, whether the solution was extensively covered by a floating polystyrene lid or not. The pH and PCO2 of the dialysate that had been covered with a floating lid remained stable during the 5 hours, whereas the corresponding values of the dialysate that had not been so covered did show changes that were secondary to the loss of carbon dioxide. The changes were not marked enough to preclude the clinical use of the latter uncovered dialysate.

Drug distribution in the vitreous humor of the human eye: the effects of aphakia and changes in retinal permeability and vitreous diffusivity

The majority of eyes that receive drug therapy exhibit some form of pathophysiological degradation. Two common pathophysiological states are retinal inflammation, which results in breakdown of the blood-retinal barrier, and aphakia. The purpose of this study was to examine the effects of aphakia and changes in retinal permeability and vitreous diffusivity on drug distribution in the vitreous humor of the human eye. The study was performed using a finite element model that accurately accounts for the vitreous geometry and boundary conditions. Intravitreal injection is the most common method for treating posterior segment disorders; therefore, this administration method was simulated using the models. Elimination from aphakic and phakic eyes was compared for four extreme injection locations and for two retinal permeabilities. When the retinal permeability was fixed at 5.0 x 10(-5) cm/s, increasing the drug diffusivity through the vitreous from 5.4 to 10(-7) to 2.4 x 10(-5) cm2/s decreased the half-life of drug from 64 hours to 2.7 hours. When the drug diffusivity was fixed at 5.6 x 10(-6) cm2/s, increasing the retinal permeability of the drug from 1.0 x 10(-7) to 1.0 x 10(-4) cm/s decreased the half-life of drug from 44 to 7 hours. Therefore, drug diffusivity and retinal permeability are key factors that influence elimination from the vitreous, and must be considered, particularly if the blood retinal barrier has been compromised. Faster drug elimination was observed in aphakic eyes than in phakic eyes, especially for drugs with a low retinal permeability and injected close to the lens capsule. Injection position is also important if the drug is injected in close proximity to a primary elimination barrier.

Drug distribution in the vitreous humor of the human eye: the effects of intravitreal injection position and volume

PURPOSE

The purpose of this study was to determine how the position and volume of an intravitreal injection affect the distribution and elimination of drug from the vitreous humor.

METHODS

A mathematical model that had been developed and used previously to study drug distribution in the vitreous humor of the rabbit eye was modified to match the physiology of the human eye. Fluorescein and fluorescein glucuronide were used as the model compounds for these studies. Four extreme injection locations were considered: a central injection, an injection displaced towards the retina, an injection displaced towards the lens, and an injection displaced toward the hyaloid membrane. Injections containing an equal mass of drug dissolved in volumes of either 15 microL or 100 microL were compared.

RESULTS

The location of an intravitreal injection was found to have a substantial effect on elimination and distribution in the vitreous. Peak concentrations at different vitreous locations varied by over three orders of magnitude, depending on the injection location. The mean concentration of drug remaining in the vitreous 24 hours after the intravitreal injection varied by up to a factor of 3.8, depending on the injection location. Changing the volume of the injection from 15 microL to 100 microL dampened the effects of the initial injection location; however, meant concentrations at 24 hours still varied by up to a factor of 2.5.

CONCLUSIONS

Careful control of the conditions of an intravitreal injection could reduce treatment variability, improve bioavailability, and reduce the possibility of retinal toxicity.

A semi-solid drug delivery system for epidermal growth factor in corneal epithelial wound healing

PURPOSE

To examine the effects of EGF, delivered from a semi-solid drug delivery system, on corneal epithelial wound healing following anterior keratectomy wound creation in the eyes of New Zealand white rabbits.

METHODS

A semi-solid drug delivery system based on a Carbopol gel was developed. Following creation of a 7.5 mm circular anterior keratectomy wound, 50 microL of either a placebo gel or an EGF-containing gel, was instilled in the inferior fornix. The gel remained in the eye for 8 hours, at which time it was removed. Anaesthesia was maintained for the entire 8-hour period. Wound healing was evaluated by quantitative morphometry. We evaluated 0.04, 0.1, 0.2, 0.4, and 1% EGF concentrations in the gel. Tear EGF concentrations and histology of the healing corneas were also examined.

RESULTS

The enhancement factor (ratio of the healing rate with the EGF gel and control gel) was 1.13 +/- 0.12, 1.40 +/- 0.14, 1.29 +/- 0.12, 1.80 +/- 0.22, and 1.09 +/- 0.12 for the gels containing 0.04, 0.1, 0.2, 0.4, and 1% EGF by mass, respectively. The increases in the rate of wound healing were significant with the 0.1, 0.2 and 0.4% gel formulations. Histologically, the 0.4% gels resulted in cellular hyperplasia after 5 days of healing. Differences between the placebo gel-treated and EGF-containing gel-treated eyes were evaluated at both 2 and 5 days. The concentration of EGF in the tears during the treatment period was approximately constant for both the 1% and 0.04% gels. The average tear concentration during the instillation period was 2.87 +/- 0.36 micrograms/mL and 200.61 ng/mL +/- 116.10 for the 1% and 0.04% gels respectively.

CONCLUSIONS

Treatment with EGF in a Carbopol gel carrier for a period of 8 hours results in significant wound healing enhancement (p < 0.05). The optimum EGF loading in the gel was determined to be 0.4%. A slow release gel may be an effective way to deliver EGF to the corneal surface.

Finite element modeling of drug distribution in the vitreous humor of the rabbit eye

Direct intravitreal injection of drug is a common method for treating diseases of the retina or vitreous. The stagnant nature of the vitreous humor and surrounding tissue barriers creates concentration gradients within the vitreous that must be accounted for when developing drug therapy. The objective of this research was to study drug distribution in the vitreous humor of the rabbit eye after an intravitreal injection, using a finite element model. Fluorescein and fluorescein glucuronide were selected as model compounds due to available experimental data. All required model parameters were known except for the permeability of these compounds through the retina, which was determined by fitting model predictions to experimental data. The location of the intravitreal injection in the experimental studies was not precisely known; therefore, several injection locations were considered, and best-fit retinal permeability was determined for each case. Retinal permeability of fluorescein and fluorescein glucuronide estimated by the model ranged from 1.94 x 10(-5) to 3.5 x 10(-5) cm s(-1) and from 0 to 7.62 x 10(-7) cm s(-1), respectively, depending on the assumed site of the injection. These permeability values were compared with values previously calculated from other models, and the limitations of the models are discussed. Intravitreal injection position was found to be an important variable that must be controlled in both experimental and clinical settings.

A partial dialysate collection method

This study validates Ing's partial dialysate collection method, which employs proportionate collection using a side tube capped with a small-gauge plastic needle. The urea nitrogen and creatinine levels of the small representative fraction of spent dialysate collected in the above fashion are undistinguishable from those obtained from the total spent dialysate. The estimated urea nitrogen removed during hemodialysis using this approach is similar to that using the total dialysate collection method; Ing's method is simple and useful in quantifying the dialysis dosage and in its assessment of the nutritional status of patients on hemodialysis.

Peptides modeled on the transmembrane region of the slow voltage-gated IsK potassium channel: structural characterization of peptide assemblies in the beta-strand conformation

A 27-residue peptide, having a sequence corresponding to the transmembrane domain of the IsK protein with slow voltage-gated potassium channel activity, has been incorporated into synthetic saturated-chain phospholipid membranes. The peptide-lipid complexes have been characterized by attenuated-total-reflection Fourier-transform-infrared spectroscopy (ATR-FTIR), spin-label electron spin resonance (ESR) spectroscopy, 31P and 2H nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and low-angle X-ray diffraction. From FTIR spectroscopy, it is found that, when reconstituted into membranes by dialysis from 2-chloroethanol, the peptide has a predominantly beta-strand secondary structure in which the peptide backbone is oriented at an angle of approximately 56 degrees relative to the membrane normal in dry films of phosphatidylcholines. Hydration of the dry film in the gel phase does not appear to affect the orientation of the peptide backbone, and a relatively small change in orientation occurs when the bilayer undergoes the transition to the fluid phase. The ESR and NMR spectra from spin-labeled and 2H-labeled phospholipids, respectively, indicate that the incorporated peptide restricts the rotational motion of the lipids, without appreciably affecting the chain order, in a way similar to that found for integral membrane proteins. The characteristic two-component ESR spectra from spin-labeled lipids further indicate a selectivity in the interaction of anionic phospholipids with the peptide. The motional restriction of the chains of the spin-labeled phosphatidylcholine and the reduction in the enthalpy of the lipid chain-melting transition indicate that, on average, approximately two to three phospholipid molecules interact directly with each peptide monomer, which is consistent with a limited degree of aggregation of the beta-sheet structures. Both 31P NMR spectroscopy and X-ray diffraction indicate that the lipid-peptide complexes have a lamellar structure up to the highest peptide concentration studied (Rp = 0.2). The surface area occupied by lipid molecules (ca. 30 A2 per chain) in the peptide complexes, deduced from the lamellar repeat spacings at defined water content, is very similar to that in pure fluid lipid bilayers, consistent with the 2H NMR results. The additional membrane surface area contributed by the peptide is approximately 112 A2 per monomer. This large value for the peptide area in the fluid bilayer is consistent with the ATR studies of dry peptide/lipid films which suggest that the long axis of the beta-strand is strongly tilted with respect to the bilayer normal (56 degrees in the dry film).

Effect of an pyruvate-based peritoneal dialysis solution on the pH of a residual peritoneal dialysis fluid

An acidic (pH 5.2) pyruvate-based peritoneal dialysis solution or an equally acidic lactate-based counterpart was added to a residual fluid (i.e., peritoneal effluent) obtained from each of 6 continuous ambulatory peritoneal dialysis patients. It was found that the residual fluids were able to raise the pH of the resultant residual fluid/peritoneal dialysis solution mixture to a higher level in the case of the pyruvate-based solution than in the case of the lactate-based one.

Pharmacokinetic differences between ocular inserts and eyedrops

Controlled release ocular inserts have been found to increase the amount of drug which is absorbed into the aqueous humour when compared to eyedrops. Systemic absorption following delivery using a controlled release insert has been found to be dependent on the release rate of the insert. The objective of this study was to determine if ocular inserts affect drug absorption into other ocular tissues such as the conjunctiva and iris-ciliary body. Ocular absorption studies were performed using albino rabbits and ethylene-vinyl acetate controlled release devices containing timolol maleate. A compartmental model previously developed to simulate ocular absorption following eyedrop administration was modified and used to simulate these experiments. The conjunctival absorption coefficient calculated by the model and the AUC of the conjunctiva per mumol of delivered drug were found to be 2.7 and 42 times higher, respectively, for the ocular insert as compared to eyedrop administration. The increased conjunctiva absorption was likely the result of reduced tear mixing, which caused a high local concentration of timolol between the insert and the conjunctiva. The AUC of the iris-ciliary body per mumol of delivered drug was found to be 24 times higher for the ocular inserts as compared to eyedrop administration. The AUC of the iris-ciliary body was found to be 1.4 times higher than the AUC of the aqueous humour for eyedrop administration, but 9 times greater for delivery via the ocular inserts. Thus, the increased absorption into the iris-ciliary body and aqueous humour observed for ocular inserts is partially the result of an increase in the amount of drug which enters these tissues via penetration across the conjunctiva and sclera.

Tear EGF concentration following corneal epithelial wound creation

The effect of corneal epithelial wound creation on epidermal growth factor (EGF) concentration in tears was evaluated in order to better understand the effects of EGF on the wound healing process. The tears of New Zealand white rabbits were sampled by micropipette one day prior to wounding, immediately prior to the creation of a 7.5 mm diameter anterior keratectomy wound, immediately following wound creation, and at 1, 2, 3, 7, and 14 days following wounding. A volume of 50 microL was taken at each sampling time, and all tear samples were assayed for EGF by an enzyme linked immunosorbent assay (ELISA). The results demonstrated that the concentration of EGF in the tear layer rises dramatically immediately following wound creation. The basal measured EGF concentration was approximately 600 pg/mL; immediately following wound creation, this rose to approximately 1600 pg/mL. By 1 day following creation of the wound, the concentration of EGF in the tears had returned to the basal level. A second, marginally significant increase in the tear concentration was noted at 3 days post wounding. The EGF concentration in the tears were not significantly different at any other time. The measured dramatic rise in EGF concentration in the tears in response to the creation of a corneal epithelial wound provides further evidence of the importance of tear EGF in the wound healing process. The concentrations in all cases were on the order of ng/mL, suggesting that the intercellular concentrations in this range result in optimal cell stimulation.

A subconjunctival degradable implant for cyclosporine delivery in corneal transplant therapy

The effect of local cyclosporine therapy upon corneal transplant survival was investigated. A high risk rabbit model with vascularized corneas was used to assess the efficacy of subconjunctivally implanted degradable devices for cyclosporine therapy. Animals were divided into four groups, receiving either no therapy, a placebo PLGA device, or drug containing devices implanted either at the time of transplantation or two weeks previous. The mean survival times of animals in the control and placebo groups were statistically equivalent (21 +/- 4 days vs 18 +/- 4 days). Devices containing CsA improved the survival time of grafts. Predosing the animals with CsA improved the survival time to 28 +/- 7 days, and CsA devices implanted at the time of transplantation increased the survival time to 35 +/- 7 days. The improvement in survival times was consistent with the in vitro drug release profiles. No systemic CsA was detected, suggesting that the effect may have been local. Histological assessment indicated that devices were well tolerated.

Contribution of hypervariable domains to the conformation of a broadly neutralizing glycoprotein 120 epitope

Three of the five hypervariable domains (V1-V3) of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 have previously been shown to be dispensable for antigenic epitopes recognized by broadly neutralizing monoclonal antibodies. In this study, the influence of the V4 and V5 domains on an epitope recognized by a broadly neutralizing human monoclonal antibody, 1.5e, was investigated. In contrast with the V1, V2, and V3 domains of gp120, the V4 and V5 domains were found to be critical for binding to both CD4 and 1.5e. Our results suggest that V4 and V5 are in structurally less flexible regions of gp120 than V1, V2, and V3 and raises the question of whether variable domains V4 and V5 are also indispensable for other broadly neutralizing antibodies in the same class as 1.5e.

Identification of malaria-infected dried mosquitoes by biotinylated DNA probe

Dot-blot hybridization with cloned genomic DNA labeled with photobiotin as a probe is used to detect Plasmodium falciparum sporozoites in dried mosquitoes. The assay is sensitive enough to detect 2 pg Plasmodium parasite DNA, or one infected mosquito in a pool of 40 insects using DNA extraction samples, or one infected mosquito in a pool of 25 insects without DNA extraction. A single mosquito squashed directly on a nitrocellulose filter for the determination of parasites provides a simple method for the detection of sporozoites. The mosquitoes triturated in reduction buffer were efficient for the screening of malaria infection of mosquitoes in a large number of samples. The species specificity, sensitivity, and ease of performance of this assay as well as the stability of the reagents may make it a useful epidemiological tool.

A compartmental model for the ocular pharmacokinetics of cyclosporine in rabbits

Studies were conducted in rabbits to determine the ocular distribution and elimination of cyclosporine, with the objective of developing a comprehensive pharmacokinetic model. Following a bolus dose into the anterior chamber, drug levels were measured in the aqueous humor, cornea, iris/ciliary body, lens, sclera, and conjunctiva. Cyclosporine was rapidly eliminated from the aqueous, but drug levels in ocular tissues persisted for in excess of 48 hours, particularly in the cornea and iris/ciliary body. The terminal elimination half life from these tissues was 45 hr and 30 hr, respectively, providing evidence that these tissues could act as a reservoir for the drug. It was found that a compartmental model accurately described the experimental data. A single compartment was used for each of the tissues and fluids sampled, except for the cornea, which was subdivided into two compartments, representing its tissue and aqueous regions.