Traumatic inflammatory response: pathophysiological role and clinical value of cytokines

Severe trauma is an intractable problem in healthcare. Patients have a widespread immune system response that is complex and vital to survival. Excessive inflammatory response is the main cause of poor prognosis and poor therapeutic effect of medications in trauma patients. Cytokines are signaling proteins that play critical roles in the body's response to injuries, which could amplify or suppress immune responses. Studies have demonstrated that cytokines are closely related to the severity of injuries and prognosis of trauma patients and help present cytokine-based diagnosis and treatment plans for trauma patients. In this review, we introduce the pathophysiological mechanisms of a traumatic inflammatory response and the role of cytokines in trauma patients. Furthermore, we discuss the potential of cytokine-based diagnosis and therapy for post-traumatic inflammatory response, although further clarification to elucidate the underlying mechanisms of cytokines following trauma is warranted.

[Investigation and analysis on the detection of IgG antibodies against the rubella virus among rural childbearing-age women in preconception period in Yunnan Province from 2013 to 2019]

A study was conducted on rural women of childbearing age aged 20-49 who underwent the National Free Preconception Health Examination Project (NFPHEP)in Yunnan Province from 2013 to 2019. Descriptive analysis was conducted to determine the negative rate of IgG antibodies against the rubella virus and its differences among various socio-demographic characteristics. Among the 1 511 203 study subjects, the negative rate of IgG antibodies against the rubella virus was 24.36%. Only 2.64% of the population had received rubella virus vaccine. The negative rate of IgG antibodies among rural childbearing-age women in the preconception period in Yunnan Province decreased with age and educational level (Ptrend<0.001). The negative rate of IgG antibodies in ethnic minority women of childbearing age in the preconception period (25.19%) was higher than that of Han women (23.88%). Among the 22 ethnic groups with over 1 000 participants, the negative rates of IgG antibodies in women of childbearing age from the Blang (32.85%), Bouyei (31.03%), Zhuang (31.01%), and Miao (30.70%) ethnic groups were higher than those of women from other ethnic groups. Among the 16 states (cities) in Yunnan Province, the negative rate of IgG antibodies in pregnant women of childbearing age in Wenshan Zhuang and Miao Autonomous Prefecture (38.06%) and Lincang City (32.63%) was higher than that in other states (cities). The negative rate of serum IgG antibodies in women who reported having received rubella virus vaccine (18.60%) was lower than that in other non-vaccinated populations (24.52%). The proportion of rural women of childbearing age in Yunnan Province who were susceptible to the rubella virus before pregnancy was still high. It is necessary to promote rubella vaccination among people susceptible to rubella, especially pregnant women, to prevent rubella virus infection and reduce the incidence rate and disease burden of rubella people.

[Analysis of prognostic factors of extranodal NK/T-cell lymphoma treated with pegaspargase/L-asparaginase: a multicenter retrospective study]

Objective: To explore the prognostic factors of extracellular NK/T cell lymphoma (ENKTL) treated with pegaspargase/L-asparaginase. Methods: The clinical data of 656 ENKTL patients diagnosed at 11 medical centers in the Huaihai Lymphoma Working Group from March 2014 to April 2021 were retrospectively analyzed. The patients were randomly divided into two groups: a training set (460 cases) and a validation set (196 cases) at 7∶3, and the prognostic factors of the patients were analyzed. A prognostic scoring system was established, and the predictive performance of different models was compared. Results: Patients' median age was 46 (34, 57) years, with 456 males (69.5% ) and 561 nasal involvement (85.5% ). 203 patients (30.9% ) received a chemotherapy regimen based on L-asparaginase combined with anthracyclines, and the 5-year overall survival rate of patients treated with P-GEMOX regimen (pegaspargase+gemcitabine+oxaliplatin) was better than those treated with SMILE regimen (methotrexate+dexamethasone+cyclophosphamide+L-asparaginase+etoposide) (85.9% vs 63.8% ; P=0.004). The results of multivariate analysis showed that gender, CA stage, the Eastern Cooperative Oncology Group performance status (ECOG PS) score, HGB, and EB virus DNA were independent influencing factors for the prognosis of ENKTL patients (P<0.05). In this study, the predictive performance of the prognostic factors is superior to the international prognostic index, Korean prognostic index, and prognostic index of natural killer lymphoma. Conclusion: Gender, CA stage, ECOG PS score, HGB, and EB virus DNA are prognostic factors for ENKTL patients treated with pegaspargase/L-asparaginase.

[Research progress of ocular manifestations and treatments of human immunodeficiency virus and syphilis co-infection]

Acquired immune deficiency syndrome caused by human immunodeficiency virus (HIV) infection is a fatal disease involving multiple systems. Syphilis is a systemic chronic infection disease caused by treponema pallidum infection. In recent years, the incidence of the two infectious diseases in China has been on the rise. Both of them have the same high-risk population and similar transmission routes, and co-infection is increasing day by day. They can influence each other. Syphilis significantly increases the risk of HIV infection, and HIV is able to change the natural course of syphilis. HIV and syphilis co-infection leads to diverse ocular manifestations which are not typical or specific. This condition results in not only a high rate of missed diagnosis and misdiagnosis, but also a high rate of treatment failure and recurrence. There is a high correlation between ocular syphilis and neurosyphilis in HIV-positive patients. Many patients with HIV/syphilis co-infection visit eye clinics for the initial symptom. In order to provide reference for clinical diagnosis, treatment and research, this article reviews the recent advances on the studies of the co-infection of HIV and syphilis, including epidemiological characteristics, ocular manifestations and treatments. (Chin J Ophthalmol, 2021, 57: 865-870).

[Retinal toxicity study of intravitreal ganciclovir in albino rabbit]

Objective: To elevated the retinal toxicity of intravitreal ganciclovir in albino rabbit eyes. Methods: Experimental study. Twenty-four New Zealand albino rabbits (forty-eight eyes) were divided into four groups by random. Three groups were prepared for ganciclovir experiment, named A, B, C. Each group received intravitreal injection ganciclovir dose at 400 μg/0.05 ml, 2 mg/0.05 ml and 5 mg/0.05 ml respectively. The other group named D served as a control accepted intravitreal injection 0.9% normal saline 0.1 ml. Before and after 1, 2 and 4 weeks, flicker full field electroretina gram (ERG) was recorded. After 1, 2 and 4 weeks light and electron microscopic tests were recorded for further toxicity study. Results: There was significant difference in amplitude of maximal combined response a wave in one week(χ(2)=8.319, P=0.04), and pairwise comparison the 5 mg group (140.50 μV) was significantly lower than the control group (165.00 μV) (χ(2)=-2.830, P=0.028). Maximal combined response b wave in four weeks(χ(2)=-10.626, P=0.014), and pairwise comparison the 5 mg group (261.50 μV) was significantly lower than the control group (398.00 μV) (χ(2)=-2.973, P=0.018). 30 Hz flicker response in one, two and four weeks(χ(2)=17.589, 8.225, 8.997, P=0.001, 0.042, 0.02), and pairwise comparison the 5 mg group (71.3μV, 106.00μV, 63.60μV) was significantly lower than the control group (118.50μV, 129.00μV, 116.50μV) (χ(2)=-4.142, -2.826, -2.713, P=0.000, 0.028, 0.040). There was no histologic retinal toxicity evidence of group 400 μg and control group observed by light microscopy in any stage of the study. Histologic changes of group 2 mg four week later, group 5 mg two and four week later include inner nuclear layer loose arranged, nuclear of ganglia were widened and outer plexiform layer stained less in four week later. By electron microscopic observation, the ultrastructure of retina changed to different degrees and became worse in each experimental group with significant mitochondrial swelling and hydropic changes were seen in the inner segments of photoreceptors, loosely arranged and disordered in the outer segment of photoreceptors four weeks later. Conclusions: The retinal function and morphology were normal in group 400 μg. Group 2 mg and 5 mg had retinal toxicity, and 5 mg was more severe. Therefore, the clinical application of ganciclovir in the treatment of acute retinal necrosis (ARN) should select the minimum effective dose to avoid the occurrence of retinal toxicity. (Chin J Ophthalmol, 2020, 56:279-285).

[Advance study of rhinocerebralmucormycosis]

Mucormycosis is a rare, rapidly progressive life threatening opportunistic fungal infection, with rhinocerebral mucormycosis being the most common type. Rhinocerebral mucormycosis usually presents symptoms similar to sinusitis and orbital cellulitis during its early stage,which often leads to a misdiagnosis at the very beginning,and progresses rapidly to endophthalmitis,blindness,sclera perforation, eyeball atrophy, and even gets the central nervous system involved, thus leading to death. Mucormycosis is particularly common in patients with poor glycemic control, ketoacidosis and immunosuppression. The purpose of this review is to highlight the predisposing factors, infection pathway, pathogenesis, clinical presentations, diagnosis, and management of rhinocerebral mucormycosis, hence further promote the early diagnosis and immediate treatment of the disease. (Chin J Ophthalmol,2019,55:629-633).

[Pathophysiology and therapeutic progress of diabetic macular edema]

Diabetic macular edema (DME) is the leading cause of vision loss in diabetics. The destruction of blood retinal barrier is the primary pathological feature. At present, a large number of animal experiments and clinical studies show that DME not only has abnormal vascular structure, but also is an inflammatory disease. A variety of inflammatory media and chemokine are involved in the process of DME. With the extensive clinical application of anti-vascular endothelial growth factor (VEGF), the treatment of DME got a revolutionary breakthrough. However, unlike proliferative diabetic retinopathy (PDR), DME patients response intensively to anti-VEGF agents and couldn't resolve completely despite of multiple injections. Therefore, in addition to VEGF, other possible therapeutic targets and clinical trials of new drugs are also widely carried out. This article reviews the therapeutic process of DME. (Chin J Ophthalmol, 2018, 54: 625-630).

[The relationship between optical coherence tomography performance and visual acuity of acute retinal necrosis]

Objective: To analyze the relationship between optical coherence tomography(OCT) performance and visual acuity of patients with acute retinal necrosis (ARN). Methods: Retrospective analysis was performed on the patients diagnosed with ARN at the ophthalmology department of Peking union hospital during October 2011 and May 2016. Fourteen patients (15 eyes), 9 males and 5 females, whose anterior and posterior inflammation disappeared and the retinal necrosis lesion in the fundus of the eye subsided were included. The mean age was (41.6±12.2) years. All patients underwent careful examinations including best corrected visual acuity (BCVA), slit-lamp microscope, indirect ophthalmoscope, color fundus picture, fundus fluorescein angiography (FFA) and OCT (results of their last consultations). Results: BCVA: 8 eyes were increased, 2 eyes were unchanged and 5 eyes were decreased at the last visit; light perception (LP) 1 eye, finger count (FC) 1 eye, 3 eyes of 0.01 to 0.1, 6 eyes of 0.15 to 0.25. The inflammatory reaction in the anterior segment of 14 eyes disappeared, while the inflammatory reaction of the remaining 1 eye was relieved. The fundus lesions of all 15 eyes disappeared. According to OCT results: five eyes (5/15) exhibited normal macula area, among the 5 eyes, 4 eyes are of 0.15 to 0.25 visual acuity, and 1 eye is of 0.5 visual acuity;macular epiretinal membrane is present in three eyes (3/15), of which the visual acuity is 0.02, 0.25 and 0.3 respectively macula edema is present in three eyes (3/15), among the 3 eyes, 1 eye (visual acuity of 0.01)showed thickening of neurosensory retina, cystoid change of fovea and several fluid dark areas, the other 2 eyes (visual acuity of 0.02 and 0.5 respectively) showed small diffuse fluid dark area in the neurosensory retina;atrophy of neurosensory retina and absence of IS/OS was found in four eyes (4/15), among the 4 eyes, the visual acuity of 3 is below 0.01, and the other 1 eye is of 0.08 visual acuity. Conclusions: The OCT performance of stationary phase of ARN tends to be positively correlated with the visual acuity of patients. The prognosis of visual acuity of the patients whose OCT results showed atrophy of neurosensory retina and absence of IS/OS is poor. (Chin J Ophthalmol, 2018, 54: 369-374).

[Research on the surgery treatment and etiology of fungal endophthalmitis]

Objective: To evaluate the efficacy of vitrectomy and etiological diagnosis in the treatment of fungal endophthalmitis. Methods: A retrospective survey was done on the clinical manifestation, etiological diagnosis and treatment efficacy of 15 patients (15 eyes) who had been diagnosed with fungal endophthalmitis at the inpatient department of Peking Union Medical College Hospital during 2002-2015. A total of 15 eyes of 15 patients, 3 male and 12 female patients, were included in this study. The mean age of the patients was (45.8±15.3) years. Among the 15 eyes, 12 (12 patients) were diagnosed with endogenous fungal endophthalmitis and 3 (3 patients) were diagnosed with exogenous fungal endophthalmitis. Fourteen eyes have been misdiagnosed with uveitis, systematic or local application of glucocorticoid and/or immunosuppressor have been conducted on the patients which resulted in exacerbation. Baseline visual acuity: light perception in 2 eyes, hand movement for 12 eyes, and 1 eye of 0.1. Six eyes showed slight inflammatory reaction in anterior chamber, four eyes showed moderate inflammatory reaction in anterior chamber, while five eyes showed severe inflammatory reaction with hypopyon in anterior chamber. B-Scan ultrasound examination showed inflammatory vitreous opacity in all 15 eyes, combined proliferative vitreoretinopathy (PVR) were found in 11 eyes, retinal detachment were found in 10 eyes, which include 6 cases of tractional retinal detachment, 1 case of exudative retinal detachment, and 3 cases of retinal and choroid detachment. Forty eyes underwent vitrectomy, 1 eye underwent intravitreal injection. Nine eyes were processed with silicone oil tamponade, one eye was processed with C(3)F(8) tamponade. At the beginning of the operation, vitreous fluids were collected for preparing smears which were later used for fungus culture and drug susceptibility testing. Results: According to the smear results of vitreous fluid, fungal hyphae and spores were found in 10 eyes. The fungus culture indicated positive results in 12 eyes, including candida albicans in 6 eyes, fusarium, candida parapsilosis, paecilomyces lilacinus, asoergullus terreus, mulan candida and aspergillus in 1 eye respectively. Based on etiological diagnosis, 14 eyes received amphotericin B intraocular injection during operation, and 9 patients received fluconazole (venous transfusion or oral administration), 2 patients received voriconazole through venous transfusion or oral administration, one patient received itraconazole through oral administration. All 15 eyes received local application of amphotericin B eyedrop or fluconazole eyedrop. The intraocular inflammations in all 15 eyes were mitigated. The visual acuity improved in 6 eyes, remained unchanged in 4 eyes, and reduced in 5 eyes. Postoperative visual acuity achieved 0.1 to 0.15 in 2 eyes, 0.01 to 0.04 in 2 eyes, CF in 2 eyes, HM in 4 eyes, LP in 2 eyes, and NLP in 3 eyes. The retina of 5 eyes remained in position, the retina of 2 eyes reattached, the retina of 2 eyes failed to reattach. Recurrent retinal detachment happened in the other 6 eyes, 5 of which received reoperation. Eventually, the retina of 10 eyes reattached, and the retina of the 5 eyes failed to reattach. Conclusions: Vitrectomy is an effective method for treatment of fungal endophthalmitis. The positive rates of vitreous smear and fungus culture were really high. Application of sensitive anti-fungal drugs based on etiological diagnose can improve therapeutic level. (Chin J Ophthalmol, 2018, 54: 270-276).

[Research progress on the diagnosis and treatment of acute retinal necrosis]

Acute retinal necrosis is an uncommon but devastating and potentially blinding ophthalmopathy featured with unfavorable prognosis as the lesions tend to develop rapidly in a circumferential way in few days. Therefore timely diagnosis and early treatment are of great significance. The polymerase chain reaction test on intraocular fluid can improve specificity and sensitivity of the etiological detection for acute retinal necrosis. Etiology results included in the diagnostic criteria is favorable for etiological diagnosis. Current treatment for acute retinal necrosis is generally based on systemic antiviral therapy, and supported by hormone and antithrombotic drugs, while surgical treatment should be considered when the disease progresses. This article reviews the research progress on the diagnosis and treatment of acute retinal necrosis in an effort to improve the diagnosis and treatment performance of acute retinal necrosis. (Chin J Ophthalmol, 2018, 54: 306-311).

[Current research of sympathetic ophthalmia]

Sympathetic ophthalmia (SO) is a rare, bilateral, non-necrotizing, granulomatous uveitis that usually occurs after open ocular injury or intraocular surgery. The pathophysiology is not clearly understood, but generally SO is an immediate hypersensitivity mediated by T lymphocytes which are related to ocular tissue antigens. The main histopathological features are granulation tissues composed of lymphocytes, macrophages and multinucleated giant cells. The clinical manifestations are different from person to person, which might be mild or severe. Although it could be presented with anterior uveitis, intermediate uveitis and posterior uveitis, panuveitis is the most common sign. The ophthalmic examinations, such as fundus fluorescein angiography, optical coherence tomography and B-scan, could be used to observe the patients' conditions and monitor the therapeutic effect. The main treatment of SO is medical therapy with corticosteroids, immunomodulators and biomodulators. Topical drug administration, including intravitreal injection of triamcinolone acetonide and implantation of a fluocinolone acetonide implant, can be considered. There is controversy about whether enucleation or evisceration is more appropriate and when the procedure should be done. The prognosis of SO could be poor. SO is liable to deteriorate and may lead to blindness. This article reviews the etiology, mechanisms, histopathology, clinical characteristics, diagnosis and treatment of SO. (Chin J Ophthalmol, 2017, 53:778-782).

[The ocular manifestations of human immunodeficiency virus and syphilis coinfection]

Objective: To investigate the ocular manifestations of human immunodeficiency virus (HIV) and syphilis coinfection. Methods: A retrospective analysis of the ocular manifestations was carried out in 27 patients (54 eyes) diagnosed as syphilis and HIV coinfection by the Department of Infectious Medicine in Peking Union Medical College Hospital during the years of 2006-2017. The research included 26 males and 1 female, aging from 24 to 76 years old, with a mean age of 40.40±12.94 years old. Ocular anterior segments were examined with slit-lamp microscope. Fundus examinations were conducted with papillary dilation, fundus photography. Results: At the first visit, there were 2 eyes without light perception, 4 eyes with light perception, 1 eye with hand movement, 1 eye with finger counting, 2 eyes with 0.01-0.09 eyesight, 8 eyes with 0.1-0.2 eyesight, 12 eyes with 0.25-0.4 eyesight, 15 eyes with 0.5-0.9 eyesight, 9 eyes with 1.0-1.5 eyesight. Among the 27 patients (54 eyes) coinfected with HIV and syphilis, keratic precipitates were identified in 20 eyes, aqueous flare positive in 20 eyes, float positive in 15 eyes, and iris posterior synechias in 7 eyes. Nineteen eyes were diagnosed as syphilis uveitis, including 2 eyes with syphilis anterior uveitis and 17 eyes with syphilis panuveitis, among which, vitreous inflammatory opacity was observed in all 19 eyes, disk atrophy in 2 eyes, optic edema in 1 eye, vitreous hemorrhage in 1 eye, retinal detachment in 2 eyes, retinal hemorrhage and white vein in 1 eye. In addition, 8 eyes were diagnosed as HIV retinopathy, all manifested as cotton-wool spot. Among the 8 eyes, 4 were diagnosed as cytomegalovirus retinitis, 3 showed retinal yellow-white lesions, and 1 was in late phase which showed retinal pigmentation. The incidence of both HIV and syphilis coinfection patients and male homosexuality population increased. The most common ocular manifestation of HIV and syphilis coinfection was syphilis panuveitis. Six patients first visited the Department of Ophthalmology, and were then diagnosed as HIV and syphilis coinfection. Conclusions: The ocular manifestations of HIV and syphilis coinfection are diversified, which can be manifested as fundus necrotic lesions as well as anterior and posterior inflammatory. For HIV positive patients, syphilis serologic test should be routinely performed. The same, syphilis positive patients should be tested for HIV serum antibodies, in order to improve the diagnosis level of HIV/syphilis coinfection and give timely etiological treatment, which is of vital importance for saving visual acuity. (Chin J Ophthalmol, 2019, 55:267-272).

[The necessity of artificial kidney seeper in the ultrasonography-guided percutaneous nephrolithotomy: a randomized controlled study]

Objective: To investigate the necessity of artificial kidney seeper which made through inserting a ureteral tube in the ureter to the ultrasonography-guided percutaneous nephrolithotomy (PCNL). Methods: This was a randomized prospective study. Patients who conformed to the inclusion and exclusion criteria were enrolled at Department of Urology, Frist Affiliated Hospital of Wenzhou Medical University from January 2016 to May 2017. Totally 291 patients were included in the study. Patients were randomly assigned into two groups (artificial kidney seeper group and non-artificial kidney seeper group) in different kidney seeper level (5 to <10 mm, 10 to 20 mm) respectively. The artificial kidney seeper group was inserted by a ureteral cathedral, then were underwent the ultrasonography-guided PCNL in prone position. The non-artificial kidney seeper group were underwent the ultrasonography-guided PCNL in prone position directly. The t test, χ(2) test, repeated measure analysis was used to data measurement, respectively. Results: Four patients who diagnosed pyonephrosis were excluded. On the 5 to <10 mm level, fever rate (14.6% vs. 4.8%, χ(2)=5.07, P=0.03), operation time ((65.7±9.9)min vs. (50.3±7.4)min, t=11.47, P=0.00), cost ((18 327±903) yuan vs. (14 583±784) yuan, t=24.50, P=0.00) about artificial kidney seeper group and non-artificial kidney seeper group had statistical differences. And on the 10 to 20 mm level, fever rate (14.5% vs. 3.39%, χ(2)=4.53, P=0.03), operation time ((66.0±9.9)min vs. (52.4±8.9)min, t=8.30, P=0.00), cost ((16 548±537) yuan vs. (13 102±629) yuan, t=32.10, P=0.00) about artificial kidney seeper group and non-artificial kidney seeper group had statistical differences. And there were no statistical differences in the success rate of puncturing, the failures of the treatment to the stone pieces falling into the ureter and clearance rate of the stone and so on. In this study, 2 cases recovered after received transfusion and digital subtraction angiography artery embolization treatments; D-J tube was indwelled into 4 cases guiding by super smooth thread; 4 cases were finished the surgeries with the help of ureteroscopy, because the stone pieces fell into the ureter during the surgeries. And there was no patients developing septic shock, adjacent viscera injury or other serious complications. Conclusion: For seasoned doctors, there is no necessity of regularly artificial kidney seeper for PCNL when the pre-operation seeper ranging from 5 to 20 mm.

[The fundus manifestations and SD-OCT findings of patients with acute Vogt-Koyanagi-Harada disease]

Objective: To conclude the characteristics of fundus appearance and spectral domain optical coherence tomography(SD-OCT) findings of patients with acute Vogt-Koyanagi-Harada (VKH) disease. Methods: The clinical data of 17 patients (34 eyes) diagnosed of acute VKH in Peking Union Medical College Hospital from Jan. 2012 to Dec. 2014 were studied retrospectively.Examinations included visual acuity, slit lamp, fundus, color fundus pictures, FFA and SD-OCT. Results: Eight men and 9 women were enrolled with mean age of (40.5±11.6) years old ranging from 26.0 to 62.0 years old. Vision acuity of their first consultations were as follows: 14 eyes (41.2%) were below 0.01-0.09, 17 eyes(50%) were among 0.1-0.3, 3 eyes (8.8%) were among 0.4-0.7. All patients were divided into 3 groups according to their fundus appearance: 14 eyes (41.2%) were optic disc swelling-type, 10 eyes (29.4%) were retinal detachment type and 10 eyes(29.4%)were mixed type. Subretinal fluid and serous retinal detachment appears in SD-OCT of all 34 eyes, with highly reflective signals in detached area. Other common characters were also noticeable, suh as RPE folds(19 eyes, 55.9%), subretinal septa (16 eyes, 47.1%) and internal limiting membrane(ILM) fluctuation (8 eyes, 23.5%). In addition, SD-OCT features were in accordance with multilobular dye pooling at late period of FFA. Conclusion: SD-OCT of acute VKH presents some typical features: subretinal fluid and serous retinal detachment, RPE folds, ILM fluctuation, and subretinal septa.(Chin J Ophthalmol, 2017, 53: 436-439).

[Application of optical coherence tomography angiography in ophthalmology]

Optical coherence tomography angiography (OCTA) is a new technology of angiography in recent years. It has advantages of the optical coherence tomography (OCT), moreover, it can hierarchically observe the vascular morphology of the retina and choroid. By using the pseudo-color, abnormal vascular structure can be distinguished from normal vascular structure of the retina. With the fusion of the OCTA image and the regular OCT image, the structure and blood flow information can be obtained at the same time. This technology provides another method of examination for clinical ophthalmology, especially for the diagnosis of retinal diseases. This review will analyze and summarize the operating principle of OCTA, its application in ophthalmology, as well as its advantages and limitations. (Chin J Ophthalmol, 2017, 53: 65-72).

Correlation analysis on total lymphocyte count and CD4 count of HIV-infected patients

OBJECTIVE

To determine the relationship between CD4 count and other blood indices and to explore the prediction of total lymphocyte count (TLC) for CD4 count in HIV-infected patients.

METHODS

Cross-sectional study was performed for the prediction of TLC and other indices for CD4 count, and historical cohort study was performed for the TLC changes as a surrogate for CD4 changes of patients on antiretroviral therapy (ART) to further understanding the utility of TLC changes for AIDS patients' management.

RESULTS

In our cross-sectional study, both TLC and white blood corpuscle count positively correlated to CD4 count, but differed in these patients. For patients on ART, the prediction of TLC for CD4 count is better than that of patient without ART. Further investigation of historical cohort study indicated that, among AIDS patients on highly active antiretroviral therapy, their TLC and haemoglobin changes also positively correlated to CD4 change, with a total correlation coefficient of 0.31 (p < 0.01) and 0.19 (p < 0.01) respectively. The prediction of TLC change for CD4 change differed each time point when patients underwent ART.

CONCLUSIONS

Total lymphocyte count and its change can be used as alternative in conjunction with other indices to CD4 count and its change in the management of HIV-infected individuals in China.

Increasing TB case detection through intensive referral of TB suspects by village doctors to county TB dispensaries

OBJECTIVE

To explore new approaches to increase the detection of tuberculosis cases (TB).

DESIGN

Thirty counties participated in the study. Patients with TB symptoms were surveyed and referred by trained village doctors to county dispensaries, designated township health centres or general hospitals for free sputum examination. TB patients and suspects notified by general hospitals were traced by TB staff if they defaulted during the transfer.

RESULTS

A total of 12,091 new smear-positive TB cases were detected. The registration rate of new smear-positives increased from 36.2 per 100,000 population before the project to 49.9/100,000 after the project, and the case detection rate under the DOTS strategy reached 86%. Of 43,464 registered TB suspects, 15,363 (35.3%) were referred by village and hospital doctors. The referral rate increased significantly (P < 0.01). Of the 15,363 referred patients, 3870 were diagnosed as new smear-positive TB cases. Among three different microscopy centres, there was a statistically significant difference in the sputum examination rates of TB suspects and in the smear-positive rates among the suspects examined. The follow-up rate was 70.9%, but the follow-up success rate was only 33.1%.

CONCLUSIONS

Intensive referral of patients with TB symptoms by village doctors to TB dispensaries is an effective way of increasing detection. At the same time, incentives are necessary for patients and village doctors.

Anti-aromatase activity of phytochemicals in white button mushrooms (Agaricus bisporus)

White button mushrooms (Agaricus bisporous) are a potential breast cancer chemopreventive agent, as they suppress aromatase activity and estrogen biosynthesis. Therefore, we evaluated the activity of mushroom extracts in the estrogen receptor-positive/aromatase-positive MCF-7aro cell line in vitro and in vivo. Mushroom extract decreased testosterone-induced cell proliferation in MCF-7aro cells but had no effect on MCF-10A, a nontumorigenic cell line. Most potent mushroom chemicals are soluble in ethyl acetate. The major active compounds found in the ethyl acetate fraction are unsaturated fatty acids such as linoleic acid, linolenic acid, and conjugated linoleic acid. The interaction of linoleic acid and conjugated linoleic acid with aromatase mutants expressed in Chinese hamster ovary cells showed that these fatty acids inhibit aromatase with similar potency and that mutations at the active site regions affect its interaction with these two fatty acids. Whereas these results suggest that these two compounds bind to the active site of aromatase, the inhibition kinetic analysis indicates that they are noncompetitive inhibitors with respect to androstenedione. Because only conjugated linoleic acid was found to inhibit the testosterone-dependent proliferation of MCF-7aro cells, the physiologically relevant aromatase inhibitors in mushrooms are most likely conjugated linoleic acid and its derivatives. The in vivo action of mushroom chemicals was shown using nude mice injected with MCF-7aro cells. The studies showed that mushroom extract decreased both tumor cell proliferation and tumor weight with no effect on rate of apoptosis. Therefore, our studies illustrate the anticancer activity in vitro and in vivo of mushroom extract and its major fatty acid constituents.

Transcriptional regulation of the mouse PNRC2 promoter by the nuclear factor Y (NFY) and E2F1

PNRC2 (Proline-rich Nuclear Receptor Coactivator 2) was previously identified through its interaction with SF1 (steroidogenic factor 1) and has been demonstrated to be a novel coactivator for multiple nuclear receptors. In this study, PNRC2 was found to be widely expressed in mouse tissues with a strong expression in lung, spleen, ovary, thymus, and colon. Alignment of mouse genomic sequence with mouse cDNA sequence (BC006598), using mouse genome browser, defines that PNRC2 gene, located on chromosome 4, contains 3 exons: 166 bp-exon I, 205 bp-exon II, and 1526 bp-exon III. The translational start site is located in exon III. The first two exons are not translated. The 420 bp coding sequence in exon III encodes a 140 amino acid protein. To understand the molecular mechanisms that regulate the expression of PNRC2 gene, we have cloned and characterized the 5'-flanking region of the gene. Potential transcriptional start sites were determined by 5' RACE analysis. Functional analysis of the 5' flanking region of the mPNRC2 gene by deletion mutagenesis, transient transfection and luciferase assays revealed that the -67/+53 region is the minimal promoter of the mouse PNRC2 gene in HeLa cells. Within this sequence we identified two putative binding sites (inverted CCAAT box) for the transcription factor NFY (nuclear factor Y), a factor mediating cell type-specific and cell-cycle regulated expression of genes, and one binding site for E2F1, a founding member of the E2F family that displays the properties of both an oncogene and a tumor suppressor gene. Mutating each individual CCAAT site or changing the orientation of the CAATT box led to a 5-fold decrease in PNRC2 promoter activity in transient transfection experiments. Gel shift, supershift assay, and ChIP analysis demonstrated the specific binding of NFY and E2F1 proteins to the mouse PNRC2 promoter. Transient transfections and luciferase assays further revealed that overexpression of NFY enhanced-promoter activity of PNRC2 gene in a dose-dependent manner while overexpression of E2F1 strongly repressed the activity of the PNRC2 promoter. Since most genes regulated by E2F1 or NFY play a regulatory role in the cell cycle, the finding that the PNRC2 promoter is activated by NFY and repressed by E2F1 indicates that in addition to functioning as nuclear receptor coactivator, PNRC2 may also play a role in the cell cycle.

[Diagnosis and treatment of Sturge-Weber syndrome associated with retinal detachment]

OBJECTIVE

To access the diagnosis and treatment of Sturge-Weber syndrome at late stage.

METHODS

The male patient aged 65 visited the eye clinic with presenting symptom of visual loss of the left eye for 2 months. Ocular examination disclosed a facial hemangioma with the size of 2 cm x 3 cm on the nasal side of the left upper eyelid associated with engorged bulbar conjunctival and episcleral vessels in the upper nasal quadrant. Ophthalmoscopy revealed total detachment of the retina. Esotropia was measured as 10 degrees. Intraocular pressure was 24 mmHg. Electroretinogram (ERG) demonstrated an indistinguished pattern. Posterior trans-scleral and ciliary body cryocoagulation was applied followed by external release of the subretinal fluid.

RESULTS

The retina became reattached with visual acuity of 0.3 and intraocular pressure was 15 mmHg of the left eye at 5 months postoperatively. Fluorescein angiographical findings were consistent with diffuse hemangioma of the choroid. Follow-up study for 6 years revealed that the retina remained attached with visual acuity of 0.8 and essentially normal electroretinogram.

CONCLUSION

The small facial hemangioma was the clue for the diagnosis of Sturge-Weber syndrome and cryocoagulation was the procedure of choice for the treatment of retinal detachment with favorable visual outcome.

Performance evaluation and planning for patient-based quality control procedures

In a recent publication, the effect of the length of time between the routine testing of quality-control (QC) samples on QC performance was studied using a newly proposed performance measure: the average number of patient samples that contain unacceptable analytic error due to an out-of-control error condition (ANPTE). We show that ANPTE also perfectly suits the evaluation of patient-based QC procedures. We used ANPTE to study the effect of the number of patient results averaged and the width of the truncation limits on an average of normals QC procedure. Estimates of ANPTE were obtained by using computer simulations that use actual patient result distributions. Based on ANPTE, the conclusions about the effects of truncation limits and number of patient results averaged on the performance of an average of normals QC procedure are substantially different from those described by others using the probability of error detection to characterize QC performance.

High-level expression of eukaryotic polypeptides from bacterial chromosomes

Attractive economics and short development timelines have often been cited as reasons for using bacteria to express eukaryotic proteins on a commercial scale. Nevertheless, routine techniques for bacterial expression of heterologous proteins are beset by a variety of technical and legal difficulties. In particular, the use of plasmids to express foreign proteins, popular promoter systems, protein fusion partners, and histidine tags and the recovery of proteins from inclusion bodies are affected by a host of issued patents. Chromosomally encoded leaderless fusions (CELF) offer a variety of technical and legal advantages over existing bacterial expression systems. In this study, we show that CELF can be used to produce a wide assortment of eukaryotic proteins at 10-liter fermentation scale.

Regulation of sugar uptake via the phosphoenolpyruvate-dependent phosphotransferase systems in Bacillus subtilis and Lactococcus lactis is mediated by ATP-dependent phosphorylation of seryl residue 46 in HPr

By using both metabolizable and nonmetabolizable sugar substrates of the phosphoenolpyruvate-dependent phosphotransferase system (PTS), we show that PTS sugar uptake into intact cells and membrane vesicles of Lactococcus lactis and Bacillus subtilis is strongly inhibited by high concentrations of any of several metabolizable PTS sugars. Inhibition requires phosphorylation of seryl residue 46 in the phosphocarrier protein of the PTS, HPr, by the metabolite-activated, ATP-dependent protein kinase. Inhibition does not occur when wild-type HPr is replaced by the S46A mutant form of this protein either in vesicles of L. lactis or B. subtilis or in intact cells of B. subtilis. Nonmetabolizable PTS sugar analogs such as 2-deoxyglucose inhibit PTS sugar uptake by a distinct mechanism that is independent of HPr(ser-P) and probably involves cellular phosphoenolpyruvate depletion.

Identification of an anaerobically induced phosphoenolpyruvate-dependent fructose-specific phosphotransferase system and evidence for the Embden-Meyerhof glycolytic pathway in the heterofermentative bacterium Lactobacillus brevis

Heterofermentative gram-positive bacteria are believed to metabolize sugars exclusively via the pentose phosphoketolase pathway following uptake via sugar:cation symport. Here we show that anaerobic growth of one such bacterium, Lactobacillus brevis, in the presence of fructose induces the synthesis of a phosphotransferase system and glycolytic enzymes that allow fructose to be metabolized via the Embden-Meyerhof pathway.

Properties of two sugar phosphate phosphatases from Streptococcus bovis and their potential involvement in inducer expulsion

Streptococcus bovis possesses two sugar phosphate phosphatases (Pases). Pase I is a soluble enzyme that is inhibited by the membrane fractions from lactose-grown cells and is insensitive to activation by S46D HPr, an analog of HPr(ser-P) of the sugar phosphotransferase system. Pase II is a membrane-associated enzyme that can be activated 10-fold by S46D HPr, and it appears to play a role in inducer expulsion.

Purification and characterization of a small membrane-associated sugar phosphate phosphatase that is allosterically activated by HPr(Ser(P)) of the phosphotransferase system in Lactococcus lactis

In the Gram-positive bacterium, Lactococcus lactis, nonmetabolizable cytoplasmic sugar phosphates, accumulated by the phosphoenolpyruvate:sugar phosphotransferase system, are rapidly dephosphorylated and expelled from the cell upon addition of glucose (inducer expulsion). Our recent studies have established that a metabolite-activated, ATP-dependent protein kinase that phosphorylates serine-46 in HPr of the phosphoenolpyruvate:sugar phosphotransferase system activates a sugar phosphate phosphatase, thus initiating the inducer expulsion process. A membrane-associated, HPr(Ser(P))-dependent phosphatase has been identified, solubilized from the membrane, separated from other cellular phosphatases, and purified to near homogeneity. It exhibits a low subunit molecular mass (10 kDa) and behaves on gel filtration columns like a monomeric enzyme. It has broad substrate specificity, optimal activity between pH 7.0 and 8.0, is dependent on a divalent cation for activity, and is not inhibited by fluoride. It is stimulated more than 10-fold by HPr(Ser(P)) or a mutant derivative of HPr, S46D HPr, in which the regulatory serine is changed to aspartate, which bears a permanently negative charge as does phosphate. Stimulation is due both to an increase in the maximal velocity (Vmax) and a decrease in the Michaelis-Menten kinetic constant (Km) for sugar phosphate. The enzyme exhibits a Ka for S46D HPr of 15 microM. Although the enzyme is thermally stable, activation by HPr(Ser(P)) is heat sensitive.

Protein phosphorylation and regulation of carbon metabolism in gram-negative versus gram-positive bacteria

Bacteria impose regulatory mechanisms on metabolic processes to ensure that the needs of the cell are met but not exceeded. Here, we discuss the basic features of a mechanism by which carbohydrate catabolism in Gram-positive bacteria is regulated. Although the physiological consequences of this regulation are the same as in Gram-negative bacteria, the mechanism is entirely different. These regulatory processes evidently evolved late, after the divergence of Gram-negative bacteria, even though the targets of regulation are universal.

Allosteric regulation of the glucose:H+ symporter of Lactobacillus brevis: cooperative binding of glucose and HPr(ser-P)

Lactobacillus brevis transports glucose and the nonmetabolizable glucose analog 2-deoxyglucose via a proton symport mechanism that is allosterically inhibited by the seryl-phosphorylated derivative of HPr, the small phosphocarrier protein of the phosphotransferase system. We have demonstrate that S46DHPr, a mutant analog of HPr which conformationally resembles HPr(ser-P) but not free HPr, specifically binds to membranes derived from glucose-grown L. brevis cells if and only if a substrate of the glucose permease is also present.

Cooperative binding of lactose and the phosphorylated phosphocarrier protein HPr(Ser-P) to the lactose/H+ symport permease of Lactobacillus brevis

Lactobacillus brevis accumulates lactose and nonmetabolizable lactose analogues via sugar/H+ symport, but addition of glucose to the extracellular medium results in rapid efflux of the free sugar from the cells due to the uncoupling of sugar transport from proton transport. By using vesicles of L. brevis cells, we recently showed that these regulatory/effects could be attributed to the metabolite-activated ATP-dependent protein kinase-catalyzed phosphorylation of serine-46 in the phosphocarrier protein HPr [HPr(Ser-P)] of the phosphotransferase system and that a mutant form of HPr with the serine-46-->aspartate replacement ([S46D]HPr) is apparently locked in the seryl phosphorylated conformation. We here demonstrate that [S46D]HPr binds directly to inside-out membrane vesicles of L. brevis that contain the lactose permease. Sugar substrates of the permease markedly and specifically stimulate binding of [S46D]HPr to the membranes while certain transport inhibitors such as N-ethylmaleimide block binding. The pH dependency for binding follows that for transport. Wild-type HPr and the [S46A]HPr mutant protein did not appreciably compete with [S46D]HPr for binding to the permease. These results provide evidence for the direct interaction of HPr(Ser-P) with an allosteric site on the lactose/proton symporter of L. brevis for the purpose of regulating sugar accumulation in response to the metabolic needs of the cell.

Regulation of 2-deoxyglucose phosphate accumulation in Lactococcus lactis vesicles by metabolite-activated, ATP-dependent phosphorylation of serine-46 in HPr of the phosphotransferase system

Lactococcus lactis takes up glucose and the nonmetabolizable glucose analogue 2-deoxyglucose (2DG) via the phosphotransferase system and extrudes the accumulated sugar phosphates in a process apparently dependent on a cytoplasmic sugar-phosphate phosphatase. Uptake of 2DG into L. lactis vesicles was shown to be dependent on an energy source, effectively provided by intravesicular phosphoenolpyruvate (PEP). 2DG phosphate (2DG-P) accumulation in these vesicles was not inhibited, and preaccumulated 2DG-P was not released from them, upon electroporation of fructose 1,6-diphosphate (FDP), gluconate 6-phosphate or 2-phosphoglycerate into the vesicles. Intravesicular but not extravesicular wild-type HPr of Bacillus subtilis alone stimulated uptake, but in the presence of any one of these metabolites, it prevented accumulation of 2DG-P. Intravesicular H15A mutant HPr inhibited uptake and allowed further inhibition of 2DG-P accumulation in the presence of the intravesicular metabolites. Intravesicular S46A mutant HPr stimulated uptake but could not promote inhibition in the presence of the phosphorylated metabolites. The S46D mutant HPr protein promoted regulation, even in the absence of a metabolite. The Vmax but not the Km value for 2DG uptake was affected. Accumulation of the natural, metabolizable substrates of the lactose, glucose, mannose and ribose permeases was inhibited by wild-type HPr in the presence of FDP or by S46D mutant HPr. The results establish that HPr serine phosphorylation by the ATP-dependent, metabolite-activated HPr kinase selectively determines the levels of sugar accumulation via the glucose and lactose permeases in L. lactis.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of the glucose:H+ symporter by metabolite-activated ATP-dependent phosphorylation of HPr in Lactobacillus brevis

Lactobacillus brevis takes up glucose and the nonmetabolizable glucose analog 2-deoxyglucose (2DG), as well as lactose and the nonmetabolizable lactose analoge thiomethyl beta-galactoside (TMG), via proton symport. Our earlier studies showed that TMG, previously accumulated in L. brevis cells via the lactose:H+ symporter, rapidly effluxes from L. brevis cells or vesicles upon addition of glucose and that glucose inhibits further accumulation of TMG. This regulation was shown to be mediated by a metabolite-activated protein kinase that phosphorylase serine 46 in the HPr protein. We have now analyzed the regulation of 2DG uptake and efflux and compared it with that of TMG. Uptake of 2DG was dependent on an energy source, effectively provided by intravesicular ATP or by extravesicular arginine which provides ATP via an ATP-generating system involving the arginine deiminase pathway. 2DG uptake into these vesicles was not inhibited, and preaccumulated 2DG did not efflux from them upon electroporation of fructose 1,6-diphosphate or gluconate 6-phosphate into the vesicles. Intravesicular but not extravesicular wild-type or H15A mutant HPr of Bacillus subtilis promoted inhibition (53 and 46%, respectively) of the permease in the presence of these metabolites. Counterflow experiments indicated that inhibition of 2DG uptake is due to the partial uncoupling of proton symport from sugar transport. Intravesicular S46A mutant HPr could not promote regulation of glucose permease activity when electroporated into the vesicles with or without the phosphorylated metabolites, but the S46D mutant protein promoted regulation, even in the absence of a metabolite. The Vmax but not the Km values for both TMG and 2DG uptake were affected. Uptake of the natural, metabolizable substrates of the lactose, glucose, mannose, and ribose permeases was inhibited by wild-type HPr in the presence of fructose 1,6-diphosphate or by S46D mutant HPr. These results establish that HPr serine phosphorylation by the ATP-dependent, metabolite-activated HPr kinase regulates glucose and lactose permease activities in L. brevis and suggest that other permeases may also be subject to this mode of regulation.

Inhibition of the phosphoenolpyruvate:lactose phosphotransferase system and activation of a cytoplasmic sugar-phosphate phosphatase in Lactococcus lactis by ATP-dependent metabolite-activated phosphorylation of serine 46 in the phosphocarrier protein HPr

Lactococcus lactis takes up lactose and the nonmetabolizable lactose analogue, thiomethyl-beta-galactoside (TMG), via the phosphoenolpyruvate:sugar phosphotransferase system (PTS) which couples sugar transport to sugar phosphorylation. Earlier studies had shown that TMG-phosphate, previously accumulated in L. lactis cells, is rapidly dephosphorylated in the cytoplasm and effluxes from the cells upon addition of glucose and that glucose inhibits further uptake of TMG. We have developed a vesicular system to analyze this regulatory mechanism and have used electroporation to shock proteins and membrane-impermeable metabolites into the vesicles. Uptake of TMG was dependent on an energy source, effectively provided by intravesicular phosphoenolpyruvate at low concentrations or extravesicular phosphoenolpyruvate at high concentrations. TMG uptake into osmotically shocked vesicles was only weakly inhibited, and expulsion of preaccumulated TMG was only slightly stimulated upon addition of glucose. Intravesicular (but not extravesicular) wild-type HPr of Bacillus subtilis completely restored the regulatory behavior observed in vivo when glucose was present in the external medium. Glucose could be replaced by intravesicular (but not extravesicular) fructose 1,6-diphosphate, gluconate 6-phosphate, or 2-phosphoglycerate, but not by other phosphorylated metabolites, in agreement with the allosteric activating effects of these compounds on HPr(Ser) kinase measured in vitro. Intravesicular mutant HPr(S46A) protein could not promote regulation of lactose permease activity when electroporated into the vesicles regardless of the presence or absence of glucose or the various phosphorylated metabolites, but the HPr(S46D) mutant protein promoted regulation, even in the absence of glucose or a metabolite, and HPr(H15A) was more effective than the wild-type protein in promoting regulation. Intravesicular wild-type and H15A HPrs, but not the S46A or S46D mutant proteins, were found to be phosphorylated by ATP under the conditions which promoted TMG efflux. In toluenized vesicles, the conditions which promoted TMG efflux also promoted TMG-P hydrolysis. These results establish for the first time that HPr serine phosphorylation by the ATP-dependent metabolite-activated HPr kinase regulates the expulsion of intracellular sugar-phosphate as well as the uptake of sugar via the PTS in L. lactis.

ATP-dependent phosphorylation of serine-46 in the phosphocarrier protein HPr regulates lactose/H+ symport in Lactobacillus brevis

Lactobacillus brevis takes up lactose and the nonmetabolizable lactose analogue thiomethyl beta-galactoside (TMG) by a permease-catalyzed lactose/H+ symport mechanism. Earlier studies have shown that TMG, previously accumulated in L. brevis cells, rapidly effluxes from the cells upon addition of glucose, and that glucose inhibits further uptake of TMG. We have developed a vesicular system to analyze this regulatory mechanism and have used electroporation to shock proteins and membrane-impermeant metabolites into the vesicles. Uptake of TMG was dependent on an energy source, effectively provided by intravesicular ATP or extravesicular arginine. TMG uptake into these vesicles was not inhibited, and preaccumulated TMG did not efflux from them upon addition of glucose. Intravesicular but not extravesicular wild-type phosphocarrier protein HPr of Bacillus subtilis restored regulation. Glucose could be replaced by intravesicular (but not extravesicular) fructose 1,6-bisphosphate, gluconate 6-phosphate, or 2-phosphoglycerate, but not by other phosphorylated metabolites, in agreement with the allosteric activating effects of these compounds on HPr(Ser) kinase measured in vitro. Intravesicular serine-46-->alanine mutant HPr cold not promote regulation of lactose permease activity when electroporated into the vesicles with or without glucose or the various phosphorylated metabolites, but the serine-46-->aspartate mutant HPr promoted regulation, even in the absence of glucose or a metabolite. HPr(Ser-P) appears to convert the lactose/H+ symporter into a sugar uniporter. These results establish that HPr serine phosphorylation by the ATP-dependent metabolite-activated HPr kinase regulates lactose permease activity in L. brevis. A direct allosteric mechanism is proposed.

Ca2+/Na+ exchanger and Na+,K+ 2Cl- cotransporter in lens fiber plasma membrane vesicles

When the Ca(2+)-sensitive fluorescent probe, Fura-2, or the Na(+)-sensitive probe, SBFI, in their cell permeable forms or the Cl(-)-specific probe, SPQ, were incubated with plasma membrane vesicles prepared from dogfish and bovine lenses fibers, there was a selective accumulation of the ion-specific probes within the vesicles. The SBFI and Fura-2 fluorescent excitation ratios of 340 nm to 380 nm (em: 505 nm) in the presence of an outwardly-directed Na+ gradient across the vesicles membrane, indicate that the influx of Ca2+ is increased by 152.5% and 147.4% for dogfish and bovine vesicles, respectively. The Na+ influx into the vesicles is also enhanced by 154.1% for dogfish and 149.1% for bovine lens when an outwardly-directed Ca2+ was present. This stimulation is not affected when either 50 microM valinomycin, or 50 mM K+ is present. The activity of this bidirectional Ca2+/Na+ exchanger could be inhibited by 100 microM bepridil or 200 microM La3+. The entrance behaviour of Cl- as monitored by the SPQ fluorescent signal indicates that, the Cl- influx is Na(+)-dependent. The Cl- influx is stimulated 152.8% and 187.6% for dogfish and bovine lens, respectively, when an inwardly-directed Na+ gradient is present, and is further enhanced when a K+ gradient is also present. The stoichiometry of Na+ to Cl- entering the vesicles was 1:2. This Na+,K+ 2Cl- cotransporter is not affected by 20 microM valinomycin or 50 mM K+. However, the transporter is completely inhibited by 50 microM furosemide.(ABSTRACT TRUNCATED AT 250 WORDS)

A Na+/H+ exchanger and its relation to oxidative effects in plasma membrane vesicles from lens fibers

The existence of a Na+/H+ exchange mechanism and its role in the regulation of lens fiber cell intracellular pH, as well as the effect of oxidants and antioxidants, have been examined in vesicular preparations from spiny dogfish and bovine eyes. The fluorescent probes, SBFI (sodium-binding benzofuran isophthalate) for Na+ and SNARF-1 (seminaphthorhodafluor-1) for H+, were used to determine fluorescent ratios in a dual-wavelength spectrofluorimeter. The results show that: (1) the plasma membrane vesicles can be purified from lens fiber (52.5% of the vesicles were in the right-side out orientation for the fish eyes and 56.3% for the bovine eyes, show enrichment for the membrane marker activities and have an average size of 0.2-0.5 microns); (2) the influx of Na+ was dependent on an outwardly directed pH gradient with the uptake of Na+ sensitive to 500 microM amiloride but not affected by 50 microM valinomycin and 50 mM K gluconate; (3) when the pHo (extravesicular pH) of the vesicles was set at 8.1 and pHi (intravesicular pH) to 6.1, an inwardly directed Na+ gradient caused an increase in intravesicular pH by about 0.3 pH unit, and in bovine lens fiber vesicles the Na+ influx is highly dependent on the intravesicular pH (or on the pHo/pHi gradient); (4) 50 microM H2O2 increases the Na+/H+ exchange rate by 174% in the vesicles derived from fish lens fibers. Similarly, 100 microM H2O2 stimulates the Na+/H+ exchange rate by 194% in bovine eye fibers. This activation is prevented by preincubation with GSH (reduced glutathione) but not with GSSG (oxidizing glutathione). We conclude that a Na+/H+ exchange mechanism is present in the lens fiber membranes. This exchange possibly regulates intracellular pH and controls the intracellular Na+ concentration. The sensitivity of the Na+/H+ exchanger to the oxidant, hydrogen peroxide (H2O2) and the protection by the antioxidant GSH suggests a possible role for the Na+/H+ exchange mechanism in the formation of cataracts.

A clinical study on diabetic retinopathy

A clinical research on the diabetic retinopathy(DR) is reported. In the 662 cases of diabetes mellitus examined, the prevalence of DR was 51.3%, of which 7.6% were preproliferative and 7% proliferative. The study showed that when the disease progressed to the preproliferative and proliferative DR, laser photocoagulation could be the best treatment of choice, and panretinal photocoagulation was also quite effective in the treatment of pregnant patients with proliferative diabetic retinopathy.

Specificity of acidic phospholipids (CL & PA) in the activation of mitochondrial F0F1 ATPase by Mg2+

The interaction of Mg2+ with native F0F1 ATPase was studied. The hydrolytic activity of F0F1 ATPase could be competitively activated by Mg2+, but the preincubation of F0F1 ATPase with cholate eliminated the Mg2+ effect. The result from the comparison of the effect of Mg2+ on F0F1 ATPase with that on soluble F1 ATPase, and the fact that the activation of Mg2+ on cholate-treated F0F1 ATPase could be reconstituted only by divalent acidic phospholipid cardiolipin, indicate that there exists a specificity between the acidic phospholipids of the mitochondrial inner membrane and Mg2+ enhancement of ATP-hydrolyzing activity of F0F1 ATPase.

The effect of Mg2+ on mitochondrial F0.F1 ATPase and characteristics of the nucleotide binding sites

The interaction of Mg2+ with nucleotide-washed F0.F1 ATPase from pig heart was studied. Mg2+ had no effect on nucleotide-washed F0.F1 ATPase, but it competitively inhibited the hydrolytic activity of washed F0.F1 ATPase preincubated with ADP and slightly activated the hydrolytic activity of washed F0.F1 ATPase preincubated with ATP. In the last two cases, it revealed negative cooperativity. The effect of Mg2+ on F0.F1 ATPase is therefore closely related to the characteristics of the nucleotide binding sites on mitochondrial F0.F1 ATPase.