Influence of the concentration of metipranolol eye drops on the drug concentration in human aqueous humour

The concentration of the metabolite of the beta-blocker metipranolol was determined in the aqueous humour of 89 cataract patients. At 1, 2 or 5 h before surgery, they received one drop (30 l) of a 0.1 % or 0.3% solution of the drug. At 1, 2 or 5 h after the application of 0.1 % metipranolol eye drops, desacetylmetipranolol concentrations of 624.55, 235.29 and 88.02 ng/ ml, respectively, were measured. At the same intervals after the instillation of 0.3% metipranolol eye drops, the respective values of 1289.20, 1120.88 and 327.36 ng/ ml were found. The metabolite concentration in the eye drops and the values measured show no consistent correlation.Offprint requests to: H. Bleckmann     

Urine test strips: reliability of semi-quantitative findings under tropical conditions

Semi-quantitative urinalysis with urine reagent strips (URS) for erythrocyturia (EU), leucocyturia (LU) and proteinuria (PU) was performed in Congolese and Sudanese school children withSchistosoma haematobium and/orS.mansoni infection. Quantitative urinalysis was performed on the same specimen using microscopy and a Neubauer counting chamber for EU and LU and the Coomassie blue dye-binding assay for PU. Microscopically detectable EU of more than 10 cells/l was found in 63% of all samples and LU of more than 20 cells/l was found in 60% of all samples. With the Coomassie blue method, PU of more than 150 mg/l was detected in 51% of all samples. URS gave positive results of grade 1–3 for EU in 69% of all samples, for LU in 63% of all samples and for PU in 66% of all samples. The sensitivity and specificity of URS compared with standard reference methods were as follows: EU 95% and 75%, LU 81% and 81% and PU 90% and 56%. When the results of all three test were combined, URS differentiated abnormal from normal urine specimens with a sensitivity of 94% and a specificity of 70%. Median quantitative results showed a good correlation with semiquantitative URS readings for all parameters, but there was a wide range of URS scores.We concluded that URS sensitively detect urinary abnormalities and thus may be used as a general screening method under field conditions when more specific methods cannot be performed. In the hospital laboratory,urine microscopy with a counting chamber would be preferred to URS as a sole method for EU and LU detection; URS is useful for the detection of PU in the tropical hospital laboratory where an appropriate quantitative method with a better specificity may not be available.     

Short time delays change pattern induced flicker colors (PIFCs)

Subjects decided on whether the colors of the rings on a modified Benham's top were the same or different. The cause of color differences was a variable time delay. Δt, of the black and white stimulus pattern on the disc. Time delays of Δt = 50 μsec and less caused detectable changes in color and brightness.     

An in vitro model for videoimaging of human bladder smooth muscle cell contractions

Knowledge regarding human bladder smooth muscle cell (SMC) physiology is very limited. Only a few specific medical therapies for bladder disorders have therefore been established. The objective of this study was to develop a model for videomicroscopy of bladder SMC contractions. Cells were isolated from human cystoprostatectomy specimens and cultured in a modified EMEM medium. These cells were identified as SMCs by means of immunohistochemistry. For videomicroscopy, the culture flasks were coated with a viscous agent to allow cell contraction. Contractions were visualized by means of a cell culture microscope with a time-lapse videosystem. For cholinergic stimulation of the cells, acetylcholine, in concentrations ranging from 100 μM to 10 mM, was applied. The percentage of contracting cells within the observation field was evaluated for quantitative analysis. In control experiments without contractile stimulant 6% of the cells were observed to contract. Stimulation with acetylcholine induced a significant dose-dependent increase to 47% in contracting cells. These results demonstrated that videomicroscopy is an appropriate tool to investigate the contraction mechanisms of bladder SMCs. This model offers the possibility of studying drug effects on the human detrusor in vitro. Received: 16 September 1999 / Accepted: 1 May 2000     

Hyperglycemia and retinopathy of prematurity in very low birth weight infants.

OBJECTIVE: Retinopathy of prematurity (ROP) remains a leading cause of morbidity in the very low-birth-weight (VLBW) infant. This study investigates a possible association between serum/blood glucose and the development of ROP. METHODS: A retrospective case-control study of all infants born between 1992 and 1997 at the Johns Hopkins Hospital with birth weights less than 1000 g who developed Stage 3 or 4 ROP was conducted. Controls either had Stage 1 ROP or no eye disease and were matched 2:1 with ROP patients for gestational age, birth weight and year of birth. Odds ratios (ORs) of ROP were calculated for multiple exposures over the first month after birth, including oxygen concentration (FiO(2)), blood glucose levels, vitamin E, mean airway pressure and mean blood pressure. RESULTS: In a simple logistic regression analysis, we found an increased ROP risk for: (1) each 10 mg/dl increase of mean glucose (OR 1.96; 95% CI 1.13 to 3.42), (2) each 1% increase of mean FiO(2) (OR 1.06; 95% CI 1.004 to 1.13), (3) history of dopamine infusion (OR 5.4; 95% CI 1.16 to 25.2) and (4) intraventricular hemorrhage Grade 3 or 4 (OR 7.3; 95% CI 1.53 to 34.7). Using a multiple regression model, we found an increased ROP risk for each 10 mg/dl increase of mean glucose (OR 2.7; 95% CI 1.003 to 7.27). Each IU/kg/day of vitamin E supplementation reduced ROP risk (OR 0.37; 95% CI 0.16-0.86). CONCLUSION: In this study, we could demonstrate that glucose levels in the first month of life are associated with the development of ROP. Further studies have to determine if this association is causal or if hyperglycemia is just an expression of severity of illness.     

Prognostic impact of ANX7-GTPase in metastatic and HER2-negative breast cancer patients.

PURPOSE: ANX7-GTPase located on chromosome 10q21 is significantly altered and associated with hormone-refractory metastatic prostate cancers. Therefore, we investigated whether levels of ANX7 correlate with breast cancer progression and survival EXPERIMENTAL DESIGN: A diagnostic tumor tissue microarray containing 525 human breast tissue specimens at different stages of the disease was assayed for ANX7 using immunocytochemical methods with ANX7 monoclonal antibody. A separate prognostic tumor tissue microarray containing 553 human breast tissue specimens annotated with clinicopathological parameters was assayed for ANX7, HER2, estrogen receptor, progesterone receptor, and p53 protein. RESULTS: We report here for the first time that the expression of ANX7-GTPase is significantly enhanced and associated with the presence of metastatic disease (P < 0.0001) in the 525 human breast tissue specimens analyzed. Furthermore, using a separate 553 case retrospective prognostic tumor tissue microarray, we found that increased ANX7 expression is also significantly associated with poor overall patient survival (P < 0.014). This is particularly true when restricted to patients in whom the BRE clinical grade is 2 (P < 0.001) or for whom there is a lack of HER2 expression (P < 0.002). Finally, Cox regression analysis shows that as the expression of ANX7 rises, the probability of survival decreases by more than 10-fold for those patients with HER2-negative tumors. These latter patients represented 66% of the population affected with breast cancer in this study. CONCLUSIONS: High levels of ANX7 in tumor correlate strongly with poor survival of HER2-negative patients and the most aggressive forms of breast cancer. This is the first study to demonstrate that ANX7 antibody has the potential for development into an in vivo diagnostic and therapeutic tool. This simple and reliable immunohistochemical assay may therefore become an important biomarker for metastatic breast cancer diagnosis and management of HER2-negative breast tumor patients.     

Immunomagnetic enrichment, genomic characterization, and prognostic impact of circulating melanoma cells.

PURPOSE: The finding of melanoma cells in the peripheral blood, thus far mainly inferred from the PCR-based demonstration of tyrosinase mRNA, has been associated with metastatic melanoma. Neither the malignant nature nor the prognostic significance of circulating cells could be established. To address this question, we analyzed immunomagnetically isolated circulating melanoma cells for chromosomal aberrations and performed a clinical follow-up study of the enrolled patients. EXPERIMENTAL DESIGN: In a prospective study, blood samples were taken from 164 melanoma patients and 50 donors without malignant disease. Circulating melanoma cells were enriched by immunomagnetic cell sorting using a murine monoclonal antibody against the melanoma-associated chondroitin sulfate proteoglycan. To prove the malignant origin of the positive cells and to define their chromosomal aberrations, we analyzed the genomes of 15 individually isolated cells from seven patients by single-cell comparative genomic hybridization (SCOMP). RESULTS: Absolute and relative frequencies of circulating melanoma cells were associated with stage and with the presence or absence of detectable tumor. The detection of two or more cells correlated significantly with a reduced survival of patients with metastatic melanoma. All of the cells that were analyzed by SCOMP displayed multiple chromosomal changes and carried aberrations typical for melanoma. CONCLUSIONS: Immunomagnetic enrichment enables isolation and genomic characterization of circulating melanoma cells. The prognostic impact on survival of metastatic patients apparently reflects the aggressiveness of an ongoing tumor spread. Direct genomic analysis of the enriched and isolated cells will help to clarify the molecular-genetic basis of the establishment of generalized melanoma.     

A comparison of forward and inverse treatment planning for intensity-modulated radiotherapy of head and neck cancer.

BACKGROUND AND PURPOSE: To compare intensity-modulated treatment plans of patients with head and neck cancer generated by forward and inverse planning. MATERIALS AND METHODS: Ten intensity-modulated treatment plans, planned and treated with a step&shoot technique using a forward planning approach, were retrospectively re-planned with an inverse planning algorithm. For this purpose, two strategies were applied. First, inverse planning was performed with the same beam directions as forward planning. In addition, nine equidistant, coplanar incidences were used. The main objective of the optimisation process was the sparing of the parotid glands beside an adequate treatment of the planning target volume (PTV). Inverse planning was performed both with pencil beam and Monte Carlo dose computation to investigate the influence of dose computation on the result of the optimisation. RESULTS: In most cases, both inverse planning strategies managed to improve the treatment plans distinctly due to a better target coverage, a better sparing of the parotid glands or both. A reduction of the mean dose by 3-11Gy for at least one of the parotid glands could be achieved for most of the patients. For three patients, inverse planning allowed to spare a parotid gland that had to be sacrificed by forward planning. Inverse planning increased the number of segments compared to forward planning by a factor of about 3; from 9-15 to 27-46. No significant differences for PTV and parotid glands between both inverse planning approaches were found. Also, the use of Monte Carlo instead of pencil beam dose computation did not influence the results significantly. CONCLUSION: The results demonstrate the potential of inverse planning to improve intensity-modulated treatment plans for head and neck cases compared to forward planning while retaining clinical utility in terms of treatment time and quality assurance.     

Expression, localization, and function of the carnitine transporter octn2 (slc22a5) in human placenta.

L-carnitine is assumed to play an important role in fetal development, and there is evidence that carnitine is transported across the placenta. The protein involved in this transfer, however, has not been identified on a molecular level. We therefore characterized localization and function of the carnitine transporter OCTN2 in human placenta. Significant expression of OCTN2 mRNA was detected in human placenta applying real-time polymerase chain reaction technology. Confocal immunofluorescence microscopy using an antibody directed against the carboxy terminus of OCTN2 protein revealed that it is predominantly expressed in the apical membrane of syncytiotrophoblasts. This was confirmed by the costaining of organic anion-transporting polypeptide B and MRP2, which are known to be expressed mainly in the basal and apical syncytiotrophoblasts membrane, respectively. To further support this finding, we performed transport studies using basal and apical placenta membrane vesicles. We could demonstrate that the carnitine uptake into the apical vesicles was about eight times higher compared with the basal ones. Moreover, this uptake was sodium- and pH-dependent with an apparent K(m) value of 21 muM and inhibited by verapamil, which is in line with published data for recombinant OCTN2. Finally, experiments using trophoblasts in cell culture revealed that expression of OCTN2 paralleled human choriogonadotropin production and thus is modulated by cellular differentiation. In summary, we show expression and function of OCTN2 in human placenta. Moreover, several lines of evidence indicate that OCTN2 is localized in the apical membrane of syncytiotrophoblasts, thereby suggesting a major role in the uptake of carnitine during fetal development.