Molecular cloning of cDNA for pro-phenol-oxidase-activating factor I, a serine protease is induced by lipopolysaccharide or 1,3-beta-glucan in coleopteran insect, Holotrichia diomphalia larvae

Previously, we identified two pro-phenol oxidase-activating factors, named PPAF-I and PPAF-II, directly involved in the activation of the purified pro-phenol oxidase (pro-PO) from the hemolymph of the coleopteran, Holotrichia diomphalia larvae [Lee, S. Y., Kwon, T. H., Hyun, J. H., Choi, J. S., Kawabata, S. I., Iwanga, S, & Lee, B. L. (1998) Eur. J. Biochem. 254, 90-97]. Here, we report molecular cloning of cDNA for PPAF-I. Based on the sequence of the cloned cDNA, the PPAF-I gene appears to encode a member of serine protease zymogen consisting of 365 amino acid residues with a molecular mass of 40193 Da. The 109 amino acid residues preceding the amino-terminus Ile residue of the mature protein seem to constitute a prepro-sequence. The mature protein is a serine protease composed of 256 amino acids with a calculated molecular mass of 28009 Da. The overall structure is highly similar to that of Drosophila easter serine protease (42.9% identity), an essential serine protease zymogen for pattern formation in normal embryonic development. The locations of disulfide linkages in the pro-segment of PPAF-I were similar to those of Tachypleus proclotting enzyme and the mammalian neutrophil-derived defensin. Furthermore, [3H]diisopropylphosphate (iPr2P)-labeled PPAF-I was specifically produced from the crude preparation of PPAF-I zymogen by incubation with lipopolysaccharide or 1,3-beta-glucan, whereas [3H]iPr2P-labeled PPAF-I was not produced under the same conditions in the absence of these microbial polysaccharides. These results indicate that the pro-PO-activation system in H. diomphalia larvae may proceed with the activation of PPAF-I zymogen by microbial polysaccharides.

Fatigue of Cord—Rubber Composites: III. Minimum Stress Effect

The dependence of fatigue lifetime on the minimum cyclic stress was assessed for the rubber matrix composite of bias aircraft tire carcass reinforced by nylon cords as well as two model rubber composites reinforced by steel wire cables. At a given stress range, the use of higher minimum stress up to a certain level led to longer fatigue life of the composite laminate. When the minimum stress exceeded this critical level, an opposite trend of shorter fatigue life occurred with a higher level of minimum stress. The initial trend of longer fatigue life of angle-plied, cord—rubber composite laminates with a higher level of minimum stress stems from a nonlinear stress—strain relationship with a tendency of strain stiffening. Under stress-controlled fatigue loading, a shorter strain range was experienced for the same stress range when the level of minimum stress was raised. However, the increase of minimum stress raises the potential for damage initiation and accumulation. This effect of increased damage potential became dominant above the critical level of minimum stress. When the fatigue life data were plotted against the values of strain range to clarify the role of damage potential, a general trend of shorter fatigue life with a higher level of minimum stress was observed at a given strain range, in striking contrast to the trend of the stress range vs the number of cycles to failure (S-N) curve in a conventional form. The result again confirms that the damage initiation and eventual fatigue failure of angle-plied, cord—rubber composite laminates are “strain-controlled” processes, as demonstrated in our preceding paper. A modified form of the Goodman equation appears to be valid in predicting the relationship between the strain range (instead of stress amplitude) and minimum strain (instead of mean stress) for a given lifetime of a cord—rubber composite laminate.

Fatigue of Cord—Rubber Composites: II. Strain-Based Failure Criteria

Fatigue failure mechanisms under low-frequency loading and their dependence on the strain properties were assessed for the rubber matrix composite of bias aircraft tire carcass reinforced by nylon cords as well as two model rubber composites reinforced by steel wire cables. Under cyclic tension at constant stress amplitude, these angle-plied, cord—rubber composite laminates exhibited localized damage in the form of cord—matrix debonding, matrix cracking, and delamination. The process of fatigue damage accumulation in the cord—rubber composite laminate was accompanied by a steady increase of cyclic strain (dynamic creep) and moderate temperature changes. The fatigue life was found to be linearly proportional to the inverse of the dynamic creep rate, i.e., the time required to increase cyclic strain by a unit amount. Regardless of the associated level of stress amplitude or fatigue life, the gross failure under low-frequency loading occurred when the total strain accumulation, i.e., cumulative creep strain, reached the static failure strain. The use of higher stress amplitude resulted in a decrease of fatigue life by simply shortening the time to reach the critical level of strain for gross failure. This observation indicates that the damage initiation and eventual structural failure of angle-plied, cord—rubber composite laminates are “ strain-controlled” processes. These critical strain properties appear to be controlled by the process of interfacial failure between the cord and matrix. Under static tension, the strain levels for cord—matrix debonding and gross failure of composite laminates showed no significant dependence on the level of carbon black loading of the matrix compound, despite the fact that carbon black loading strongly affected the modulus, strength and strain properties of the matrix. Also the number of debonding sites around the cut ends of cords increased at almost the same rate as the static strain increased regardless of the variation of matrix properties.

Identification and characterization of novel antimicrobial decapeptides generated by combinatorial chemistry

Novel combinatorial libraries consisting of simplified amino acid sequences were designed to screen for peptides active against the Candida albicans membrane. A novel decapeptide, KKVVFKVKFK, that had a unique primary amino acid sequence was identified in this work. This peptide irreversibly inhibited the growth of C. albicans and showed a broad range of antibacterial activity but no hemolytic activity. Circular dichroism spectra revealed that the predominant secondary structure of this peptide strongly depended on the membrane-mimetic environments; the peptide preferred to form an amphipathic alpha-helical structure in the presence of 50% trifluoroethanol, while it preferred to adopt a distorted alpha-helical structure in the presence of sodium dodecyl sulfate micelles. Experiments in which dye was released from vesicles indicated that this novel antimicrobial peptide killed microorganisms through the action on the membrane as its primary target. Replacement of amino acids in this active decapeptide on the basis of information from the libraries could provide unique information about factors affecting its antimicrobial activity such as its secondary structure, net positive charge, and hydrophobicity.

A randomized comparison of the safety and efficacy of once-daily gentamicin or thrice-daily gentamicin in combination with ticarcillin-clavulanate

PURPOSE

The primary purpose of the clinical trial was to assess the safety and efficacy of once-a-day compared with three-times-a-day gentamicin in patients with serious infections who had protocol-determined peak serum aminoglycoside concentrations.

PATIENTS AND METHODS

A total of 249 hospitalized patients with suspected or proven serious infections were randomized in a 2:2:1 ratio to gentamicin given three times a day with ticarcillin-clavulanate (TC), gentamicin once a day with TC, or ticarcillin-clavulanate (TC) alone. The gentamicin once-a-day dosage for patients with estimated creatinine clearance values of > or =80 mL/min was 5.1 mg/kg. With lower creatinine clearance estimates, the mg/kg dosage of gentamicin was decreased, and the dosage intervals (once daily or three times a day) were maintained. Evaluability required documentation of achievement of protocol-defined peak serum gentamicin levels.

RESULTS

Of the total 175 evaluable patients, there were no significant differences found between treatment regimens with respect to clinical or microbiologic efficacy. Bedside audiometry proved impractical due to the frequency of altered mental state in ill patients. Based on the traditional increase in serum creatinine values from baseline values, no differences in renal toxicity between the treatment groups was identified. When changes in renal function were reanalyzed based on maintaining, as opposed to worsening, of renal function, preservation of renal function was better in the gentamicin once-a-day patients as opposed to the gentamicin three-times-a-day patients, P <0.01.

CONCLUSIONS

Gentamicin once a day plus TC, gentamicin three times a day plus TC, and TC alone had similar effects in seriously ill hospitalized patients. The incidence of nephrotoxicity was similar in the three treatment groups. Using a nonvalidated post-hoc analysis, renal function was better preserved in gentamicin once-a-day + TC and TC-only patients as opposed to gentamicin three-times-a-day + TC.

Identification and characterization of the antimicrobial peptide corresponding to C-terminal beta-sheet domain of tenecin 1, an antibacterial protein of larvae of Tenebrio molitor

An active fragment was identified from tenecin 1, an antibacterial protein belonging to the insect defensin family, by synthesizing the peptides corresponding to the three regions of tenecin 1. Only the fragment corresponding to the C-terminal beta-sheet domain showed activity against fungi as well as Gram-positive and Gram-negative bacteria, whereas tenecin 1, the native protein, showed activity only against Gram-positive bacteria. CD spectra indicated that each fragment in a membrane-mimetic environment might adopt a secondary structure corresponding to its region in the protein. The leakage of dye from liposomes induced by this fragment suggested that this fragment acts on the membrane of pathogens as a primary mode of action. A comparison between the structure and the activity of each fragment indicated that a net positive charge was a prerequisite factor for activity. To the best of our knowledge this is the first report in which the fragment corresponding to the beta-sheet region in antibacterial proteins, which consists of alpha-helical and beta-sheet regions, has been identified as a primary active fragment.

Isolation and characterization of a novel 98-kd Dermatophagoides farinae mite allergen

BACKGROUND

Exposure to allergens from house dust mites is a significant cause of immediate hypersensitivity. Thus far, the active mite allergens defined are low molecular weight (MW) proteins or glycoproteins. However, other important mite allergens remain to be investigated. In this study a high MW mite antigen with a high IgE-binding activity was characterized.

METHODS

An anti-Dermatophagoides farinae (Df) monoclonal antibody, mAb642, which recognized a 98-kd allergenic mite protein, was used for affinity chromatography. The purified Df642 was characterized biochemically and immunologically.

RESULTS

Competitive ELISA demonstrated that mAb642 was inhibited by the interaction between serum IgE from allergic patients and Df642 antigen in a dose-dependent fashion. The IgE reactivity to both 98-kd and 92-kd components was removed or diminished by preincubation of asthmatic sera with Df642-coated CNBr-activated cellulose-4B gel. Two-dimensional immunoblot analysis revealed that there are at least 4 isoforms of Df642 that represent a minor component in the crude mite extract. The allergenicity of Df642 was assayed by IgE immunoassay with a large panel of 67 sera from asthmatic patients with positive skin reactions, and Df 642 showed positive IgE reactivity with more than 80% of the sera tested. Thus it should be classified as an important allergen. In addition, amino acid sequence analysis revealed that Df642 shares more than 50% homology with paramyosin from invertebrates.

CONCLUSION

We have identified and characterized a 98-kd house dust mite allergen that showed greater than 80% IgE reactivity with sera from patients allergic to mites. This is the first high MW allergen characterized to date, and it shares high sequence homology with paramyosins in invertebrates.

Tamoxifen inhibits GH3 cell growth in culture via enhancement of apoptosis

OBJECTIVE

To investigate the antitumor effects of tamoxifen on pituitary tumor GH3 cells, which lack receptors for dopamine.

METHODS

GH3 cells were treated with tamoxifen (10(-7) mol/L), bromocriptine (10(-8) mol/L), or a combination of tamoxifen and bromocriptine in serum-free media. The cell number, bromodeoxyuridine (BrdU) labeling ratio, and apoptotic ratio were assessed. Prolactin (PRL) expression was examined using immunocytochemistry and Western blot analysis.

RESULTS

After tamoxifen treatment for 4 days, the cell number decreased to 53.0% of that of untreated control cells. The percentage of PRL-immunoreactive GH3 cells decreased to 2.9%, versus 8.6% of untreated control cells, which was compatible with the results of Western blot analysis for PRL. Apoptosis increased to approximately three times that of untreated control cells at Day 2 of treatment, whereas no significant change was shown in BrdU incorporation. These effects by tamoxifen were not observed in the simultaneous treatment with 17beta-estradiol. Bromocriptine did not change the cell number, BrdU incorporation, the apoptotic ratio, or the percentage of PRL-positive cells, and it was also shown that tamoxifen did not change the sensitivity of GH3 cells to bromocriptine treatment.

CONCLUSION

Tamoxifen, an antiestrogen, exerts its antitumor effect on GH3 cells in two ways: by suppression of cell growth and by causing a decrease in PRL. Apoptosis seems to contribute to the inhibition of GH3 cell growth.

The Glaucoma Symptom Scale. A brief index of glaucoma-specific symptoms

OBJECTIVE

To develop a brief symptom survey specific for persons with glaucoma, the Glaucoma Symptom Scale (GSS).

DESIGN

Cross-sectional study of symptoms, functional impairment, and vision-targeted health-related quality of life among persons with glaucoma.

PATIENTS

A sample of 147 persons with glaucoma among a broad range of treatment categories from 4 tertiary care glaucoma centers and 44 persons without eye disease enrolled from the same 4 centers.

MAIN OUTCOME MEASURES

Participants completed a modified version of the Ocular Hypertension Treatment Study 10-item symptom checklist. Participants also completed 2 vision-specific measures, the National Eye Institute Visual Function Questionnaire and the VF-14. Participants underwent a clinical evaluation, including ocular and medical history, dilated ophthalmic examination, and Humphrey 24-2 automated visual field testing.

RESULTS

The GSS has 2 underlying domains that demonstrate sufficient internal consistency reliability for between-group comparisons. The GSS discriminates well between persons with and without glaucoma. Additionally, tests of association with clinical markers of glaucoma severity support the clinical validity of the measure and tests of association with established vision-targeted measures provide evidence of construct validity.

CONCLUSION

The simplicity, brevity, and psychometric properties of the GSS support its use in clinical practice and research to quantify symptoms in patients with glaucoma and to assist in investigations concerning the effect of glaucoma and treatments.

In vitro activation of pro-phenol-oxidase by two kinds of pro-phenol-oxidase-activating factors isolated from hemolymph of coleopteran, Holotrichia diomphalia larvae

Previously, we purified and characterized a pro-phenol-oxidase (pro-PO) of 79 kDa from coleopteran insect, Holotrichia diomphalia larvae [Kwon et al. (1997) Mol. Cells 7, 90-97]. Here, we describe the identification of two pro-PO-activating factors (PPAF), named PPAF-I and PPAF-II, directly involved in the activation of the isolated pro-PO. When pro-PO was incubated with either PPAF-I or PPAF-II, no phenol oxidase activity was observed. However, incubation of pro-PO with both PPAF-I and PPAF-II specifically exhibited phenol oxidase activity. The purified PPAF-I with a molecular mass of 33 kDa on SDS/PAGE had characteristics of a serine protease. It exhibited amidase activity against fluorogenic peptide substrates, tert-butoxycarbonyl-phenylalanyl-seryl-arginyl-4-methylcoumaryl-7-amide being the best among the substrates examined. The activity was completely inhibited by 0.02 mM p-nitrophenyl-p'-guanidinobenzoate HCl and diisopropylflurophosphate. The NH2-terminal sequence of PPAF-I had significant sequence similarity to those of serine proteases. On the other hand, the purified PPAF-II had a molecular mass of 40 kDa on SDS/PAGE and 400 kDa determined by gel filtration, indicating an oligomeric protein. The NH2-terminal sequence of PPAF-II showed no similarity to known proteins. PPAF-II exhibited no amidase activity against the fluorogenic substrates. Reconstitution experiments and immunoblotting analysis using affinity-purified antibody against pro-PO demonstrated that PPAF-I first cleaves the intact pro-PO to an intermediate of 76 kDa with no phenol oxidase activity, and then, PPAF-I converts the intermediate to the active phenol oxidase of 60 kDa in the presence of PPAF-II. These results indicate that the activation of pro-PO system in hemolymph of H. diomphalia larvae is accomplished by at least two activating factors, a serine protease and a protein cofactor.

Plasma vitamins A, C and E in the general population of Singapore, 1993 to 1995

The National University of Singapore Heart Study measured cardiovascular risk factors, including selected plasma vitamins, on a random sample of the general population aged 30 to 69 years. Plasma vitamins A and E were normal and similar by ethnic group. Mean plasma vitamin A levels were: Chinese (males 0.68 and females 0.52 mg/L), Malays (males 0.67 and females 0.54 mg/L), and Indians (males 0.66 and females 0.51 mg/L). Mean plasma vitamin E levels were: Chinese (males 12.6 and females 12.6 mg/L), Malays (males 13.6 and females 13.3 mg/L), and Indians (males 12.9 and females 12.8 mg/L). No person had plasma vitamin A deficiency (< 0.01 mg/L) and only 0.1% had vitamin E deficiency (< 5.0 mg/L). In contrast, plasma vitamin C was on the low side and higher in Chinese than Malays and Indians. Mean plasma vitamin C levels were: Chinese (males 6.3 and females 8.4 mg/L), Malays (males 5.1 and females 6.4 mg/L), and Indians (males 5.7 and females 6.9 mg/L). Likewise, the proportions with plasma vitamin C deficiency (< 2.0 mg/L) were lower in Chinese (males 14.4 and females 0.7%), than Malays (males 19.7 and females 7.2%), and Indians (males 17.8 and females 11.0%). Relatively low levels of plasma vitamin C may contribute to the high rates of coronary heart disease and cancer in Singapore. In particular, lower plasma vitamin C in Malays and Indians than Chinese may contribute to their higher rates of coronary heart disease. However, plasma vitamin C does not seem to be involved in the higher rates of cancer in Chinese than Malays and Indians. The findings suggest a relatively low intake of fresh fruits and a higher intake is recommended. Also, food sources of vitamin C may be destroyed by the high cooking temperatures of local cuisines, especially the Malay and Indian ones.

Two hevein homologs isolated from the seed of Pharbitis nil L. exhibit potent antifungal activity

Two antifungal peptides (Pn-AMP1 and Pn-AMP2) have been purified to homogeneity from seeds of Pharbitis nil. The amino acid sequences of Pn-AMP1 (41 amino acid0 residues) and Pn-AMP2 (40 amino acid residues) were identical except that Pn-AMP1 has an additional serine residue at the carboxyl-terminus. The molecular masses of Pn-AMP1 and Pn-AMP2 were confirmed as 4299.7 and 4213.2 Da, respectively. Both the Pn-AMPs were highly basic (pI 12.02) and had characteristics of cysteine/glycine rich chitin-binding domain. Pn-AMPs exhibited potent antifungal activity against both chitin-containing and non-chitin-containing fungi in the cell wall. Concentrations required for 50% inhibition of fungal growth were ranged from 3 to 26 micrograms/ml for Pn-AMP1 and from 0.6 to 75 micrograms/ml for Pn-AMP2. The Pn-AMPs penetrated very rapidly into fungal hyphae and localized at septum and hyphal tips of fungi, which caused burst of hyphal tips. Burst of hyphae resulted in disruption of the fungal membrane and leakage of the cytoplasmic materials. To our knowledge, Pn-AMPs are the first hevein-like proteins that show similar fungicidal effects as thionins do.

Urinary homovanillic acid (HVA) and vanillymandelic acid (VMA) in workers exposed to manganese dust

The neurotoxicity of manganese (Mn) is well known, however, the neurochemical effect caused by this metal is less well investigated. In this study, urinary homovanillic acid (HVA) and vanillymandelic acid (VMA), two end products of catecholamine metabolism, were measured in 39 workers chronically exposed to Mn in a manganese smelting plant. The average duration of Mn exposure was 17.4 yr. Nineteen nonexposed workers were also studied. Concentrations of Mn in serum (MnS) and in urine (MnU) were measured by Zeeman graphite furnace atomic absorption spectrophotometry (ZAAS), and HVA and VMA determined by high performance liquid chromatography (HPLC). For Mn-exposed workers, the concentration of MnS was nearly 2.8 times (1.61 +/- 0.16 mg/L vs 0.56 +/- 0.16 mg/L) and MnU about 4.5 times higher (7.62 +/- 0.17 mg/L vs 1.69 +/- 0.16 mg/L) than the nonexposed. Although the geometric mean concentration of HVA in exposed workers was similar to that of the nonexposed (3.09 +/- 1.39 mg/g cre. vs 2.99 +/- 1.40 mg/g cre.), the VMA concentration was significantly higher (3.02 +/- 1.43 mg/g cre. vs 2.49 +/- 1.58 mg/g cre., p = 0.033). Multiple regression analysis showed that although there were no correlations between any of these parameters with the duration of exposure to Mn, both HVA and VMA showed significant correlations with increase in MnS and MnU. These data provide evidence that exposure to Mn was associated with measurable increase in catecholamine metabolites. This finding is compatible with recent observations in laboratory animals that Mn interferes with neurochemical metabolism.

Expression of 32/67-kDa laminin receptor in laminin adhesion-selected human colon cancer cell lines

Laminin promotes the malignant phenotype, and the expression of certain laminin receptors is increased in malignancy. Previously, we demonstrated that a laminin-adhesive subclone of a human colon cancer cell line showed increased tumorigenicity in nude mice and increased affinity of the beta1 integrin for laminin relative to the laminin-non-adhesive subclone. The total amount of either beta1 integrin protein or mRNA did not increase. As levels of the 32/67-kDa laminin receptor (67LR) correlate with malignancy, we examined 67LR expression in the laminin adhesion-selected human colon cancer cells. The laminin-adhesive subclone, which was more tumorigenic in both heterotopic and orthotopic locations than in a laminin-non-adhesive subclone, showed cell-surface membrane staining of 67LR, whereas the laminin-non-adhesive subclone showed cytoplasmic staining of 67LR. No difference in either the amount of 67LR mRNA or the amount of protein was observed in the parental cells than in the laminin-adhesive and non-adhesive subclones. When assayed on a laminin affinity column, more 67LR molecules bound to the column with cell extracts from the laminin-adhesive subclone than was observed with the non-adhesive subclone. These findings suggest that the increased tumorigenicity of laminin adhesion-selected tumour cells might be due to an alteration in the distribution and/or adhesiveness of multiple receptors including 67LR and beta1 integrin.

Comparative analysis of conjugated bile acids in human serum using high-performance liquid chromatography and capillary electrophoresis

This paper describes the analysis of conjugated bile acids in human serum using reversed-phase high-performance liquid chromatography (HPLC) and micellar electrokinetic capillary electrophoresis (CE). Samples of healthy subjects and patients with different hepatic diseases were pretreated with a simple preparation procedure using a solid-phase extraction technique. The optimal analytical conditions of both chromatographic methods were investigated for the convenience and reliability for routine analysis. Both HPLC and CE methods were found to be reliable and compatible. The recoveries of nine bile acid conjugates using both methods were generally >85% and reproducibility >90%. The day-to-day variation of retention time was <5% for HPLC, while the variation of migration time for CE was <3%. Although the detection limit of the HPLC method (1 nmol/ml) was five times more sensitive than that of the CE method, the CE method was considered to be more time and cost effective.

Detection of oxidative DNA damage in human sperm and the association with cigarette smoking

The present study aims to evaluate oxidative DNA damage in human sperm and the association with cigarette smoking. The level of 8-hydroxydeoxyguanosine (8-OHdG) in sperm DNA, cotinine concentration in seminal plasma, and conventional seminal parameters such as semen volume, sperm density, viability, motility, and normal morphology were determined in 60 healthy subjects. It was found that the sperm DNA of smokers contained a significantly higher amount of 8-OHdG than that of nonsmokers (6.19 +/- 1.71 vs. 3.93 +/- 1.33 8-OHdG/10(5) dG, P < 0.001). The level of 8-OHdG in sperm DNA was also closely correlated to seminal cotinine concentration (r = 0.38, P < 0.05). These findings suggest that cigarette smoking enhances the extent of DNA damage in sperm. In contrast, no significant difference was observed for conventional parameters between smokers and nonsmokers, suggesting that the level of 8-OHdG in sperm may reflect the deleterious effect of cigarette smoking on sperm quality more accurately than conventional seminal parameters. Further investigation is required to understand the exact biologic and pathologic significance of oxidative damage to sperm DNA and the possibility of using 8-OHdG for the assessment of sperm quality.

Hypopyon uveitis following panretinal photocoagulation

The authors describe the rare complication of hypopyon uveitis following panretinal photocoagulation. A 55-year-old man with a history of diabetes mellitus and previous repair of a retinal detachment by scleral buckle and vitrectomy was referred to the authors after a hypopyon uveitis developed following supplemental panretinal photocoagulation. The patient was treated with frequent topical steroids in addition to periocular injection of steroids with resolution of the inflammation. Risk factors for anterior segment ischemia, such as a history of a scleral buckle, may predispose diabetic patients to the complication of hypopyon uveitis following panretinal photocoagulation.

Structural modifications of interleukin-2 at positions 47 and 65

Interleukin-2 (IL-2) is a cytokine essential for the growth and proliferation of T-cells. The purpose of this research was to study the effects of altering the "kink" caused by Pro in an alpha-helix of the protein. The Pro-47 residue was chosen because it was originally, but mistakenly, traced to the kink of an alpha-helix [1]. Pro-65 is now recognized to be situated in the middle of helix B [2]. To study the significance of this Pro for the bioactivity and overall conformation of IL-2 it was mutated to Gly and Ala. We successfully obtained 17 different mutants at position 47 and two mutants at position 65. Certain amino acid substitutions representing different categories of amino acids, namely, acidic, neutral and helix stabilizing, were chosen for more thorough investigation. The results showed that Asn-47 and Asp-47 decreased the bioactivity of these mutants by 50- and 700-fold respectively, while the Kd to its high affinity receptors was increased 180- and 90-fold respectively, compared to IL-2. The intermediate binding affinity of Asn-47 and Asp-47 was decreased 8- and 37-fold, respectively. On the other hand, Gly-47, Gly-65 and Ala-65 showed less dramatic decreases in bioactivity and high affinity binding. The intermediate binding affinity of these mutants decreased from 5- to 3-fold and low affinity binding decreased approximately 4-fold suggesting some structural and conformational changes. From these observations, we conclude that Asn-47 or Asp-47 disrupt the hydrophobic packing of the core and thus changed the overall conformation of the protein, thereby giving rise to partial agonists. Although Pro-65 lies within the helix, it may be near the surface of the protein but may not be the actual binding site and thus any conservative mutation can be better tolerated.

Entoptic evaluation of diabetic retinopathy

PURPOSE

Studies using optimized entoptic viewing of the parafoveal retinal vasculature have shown that normal subjects see their own capillaries with greater detail in the fovea than seen typically in fluorescein angiography. The authors have extended these investigations to persons with diabetes to evaluate the sensitivity, specificity, and accuracy with which they can detect and locate their own parafoveal retinal defects untrained.

METHODS

A vascular entoptoscope using Maxwellian view optics creates a high-contrast entoptic view of retinal vasculature abnormalities in the parafoveal area. Using a double-masked protocol, 70 patients with diabetes and 29 control subjects described, drew, and quantified their entoptic image. These entoptic records were compared to angiograms and color photographs obtained immediately after the entoptic evaluation.

RESULTS

Angiograms or color photographs or both showed that 61 of 70 patients with diabetes had retinal defects (e.g., microaneurysms or exudates or both) within the field of view of the Vascular Entoptoscope (8.1 degrees or 11.6 degrees circular field depending on the Vascular Entoptoscope used: parafoveal area subtends approximately 9.7 degrees). Of these 61 patients with diabetes, 51% (31) observed dark "spots" or "blobs" in the entoptic field corresponding to retinal defects in the angiograms or photographs or both. Seven (18%) of the 38 patients (9 patients with diabetes and 29 control subjects without defects in the entoptic field) said they saw something when angiograms or photographs or both showed nothing (false-positive). Thus, the sensitivity and specificity (using angiograms or photographs or both as the gold standard) with which untrained patients with diabetes detect their own parafoveal area defects are 51% and 82%, respectively. Superimposition of the entoptic image (as drawn by the patient) and the angiograms or color photography or both often showed excellent correspondence. Most (22 of 29) of the control subjects and more than half (40 of 70) the patients with diabetes were able to quantify the size of their foveal avascular zone (FAZ) from the entoptic view, whereas only 22 of 70 of the capillary loops defining the FAZ were visible in the optimal frame of the capillary phase of the fluorescein angiogram. As reported previously in a smaller sample, large FAZs often were associated with poor visual acuity.

CONCLUSIONS

More than half the untrained patients with diabetes were able to visualize their own parafoveal retinopathy entoptically, and most untrained patients with diabetes and control subjects where able to quantify the size of their FAZ. Patients and control subjects without parafoveal defects rarely report defects not visible photographically. Patients can be trained to detect their defects. Clinical entoptic monitoring will require verification that patients can detect changes in their retinopathy. Entoptic testing is low cost, noninvasive, and can be performed as often as needed at no risk to the patient. It is, therefore, a promising research technique for subjective monitoring of the early natural history of parafoveal area disease processes.

Purification and characterization of prophenoloxidase from the hemolymph of coleopteran insect, Holotrichia diomphalia larvae

Prophenoloxidase (pro-PO), a precursor of phenol oxidase (PO), was purified from the hemolymph of coleopteran Holotrichia diomphalia larvae. The enzyme was purified to apparent homogeneity, in six steps of chromatography, using Sephadex G-100, CM-52, Dextran-sulfate Sepharose CL-6B, Phenyl Sepharose CL-4B, Sephacryl S-200, and a Mono-Q column. The preparation exhibited a single band on SDS-PAGE. The proenzyme had a molecular weight of 158 kDa, as estimated by gel filtration. On SDS-PAGE under reducing conditions, it gave a 79 kDa band, indicating that it forms a dimer of the 79 kDa protein. On the other hand, the purified pro-PO gave two well-separated peaks, named pro-PO-1 and pro-PO-2, on reverse-phase HPLC. Amino acid compositions of both proteins were indistinguishable, thereby suggesting the presence of an allelic variant or an isoprotein. On dextran-sulfate Sepharose CL-6B chromatography, a fraction containing prophenoloxidase activating enzyme(s) (PPAE fraction), free from pro-PO, was also separated. In reconstitution experiments, the activation of purified pro-PO by PPAE fraction, was observed in the presence of 5 mM Ca2+, with a specific limited proteolysis. The NH2-terminal sequence of generated PO was determined to be NH2-Phe-Gly-Glu-Asp-Asp-. The activated PO oxidized o-diphenols but did not oxidize mono-phenol and p-diphenol substrates. The purified pro-PO was not activated by trypsin, alpha-chymotrypsin, and SDS.

High-performance liquid chromatographic determination of dehydroabietic and abietic acids in traditional Chinese medications

In Asia, there is still a high usage of traditional Chinese medicament by the general population. Some patients with contact dermatitis to these medicaments have been found to be sensitive to colophony on patch testing. Dehydroabietic acid (DHAA) and abietic acid (AA) are the main components of colophony and believed to be the agents responsible for skin sensitization. This paper describes a reliable high-performance liquid-chromatographic method for determining these two resin acids in ointment samples. The samples were either pretreated with diethyl ether or treated with acetonitrile directly by ultrasonication for 30 min. One volume of this sample was added to an equal volume of water and purified by solid-phase extraction. The mobile phase used was methanol-water-phosphoric acid (87:13:0.02, v/v) and the flow-rate was 1 ml/min. DHAA and AA were detected at 4.3 and 6.3 men with ultraviolet detection at wavelength 200 and 239 nm, respectively. However, fluorimetric detection with an excitation wavelength of 225 nm and emission wavelength of 285 nm, provided more selective determination of DHAA. The detection limits for DHAA and AA were 1 ng. Analytical recovery generally exceeded 90%. We analyzed nine types of commonly used topical Chinese medicaments and two types of Western medical ointments in Singapore. The results showed that most of these medicaments contain colophony below 5 ppm (micrograms g-1). Only one Chinese medicament contained > 70 ppm of both allergens and one of the Western medical ointments contained 0.2% of DHAA and 2.2% of AA.

Chiasmal infarction and sudden blindness caused by mucormycosis in AIDS and diabetes mellitus

PURPOSE

To report rapidly progressive rhino-orbitocerebral mucormycosis in a 47-year-old woman with both diabetes mellitus and the acquired immunodeficiency syndrome (AIDS).

METHOD

Case report including postmortem examination of the eyes, orbit, and brain of a patient with rhino-orbitocerebral mucormycosis, diabetes mellitus, and AIDS.

RESULTS

Invasion by hyphae of the Rhizopus species produced an occlusive vasculitis and massive infarction of the optic chiasm. Fungal organisms were discovered in multiple granulomata of the optic nerve.

CONCLUSION

Infarction at the optic chiasm probably caused sudden blindness in this patient.

Autosomal-dominant anomalies of the iris pigment epithelium

PURPOSE

The authors document two families in which anomalies of the iris pigment epithelium occur as an autosomal dominant trait.

METHODS

Eyes of members of two families were examined for the presence of anomalies of the iris pigment epithelium.

RESULTS

In both families, anomalies characterized by iris pigment epithelial cysts and peripupillary ruffles were observed in successive generations. In one family, the proband was 3 months of age, and both cysts and ruffles were present in affected individuals.

CONCLUSIONS

Anomalies of the iris pigment epithelium can be inherited in an autosomal-dominant pattern. The cystic and ruffled phenotypes represent variable expressivity and may be evident in infancy.

Determination of heterocyclic amines in flame-grilled fish patty by capillary electrophoresis

A simple and reliable capillary zone electrophoretic (CZE) method for quantifying mutagenic and carcinogenic heterocyclic amines (HCAs) in cooked foods with UV-visible diode-array detection is described. The buffer system consisted of 50 mM disodium hydrogen phosphate, 30 mM sodium chloride, 20 mM citric acid and 26% methanol at pH 2.1. An uncoated silica tubing, 51 cm in length, was used for the CZE separation. The capillary tubing temperature was maintained at 25 degrees C with a constant voltage of 20 kV. The reproducibility of the method was over 95% for a five-replicate analysis of 10 micrograms/l-spiked 2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline (4,7,8-TriMeIQx) and the detection limit was in the low microgram/l range with coefficients of variation between 6 and 18%. An analytical run took only 15 min for 12 known HCAs. Using this procedure, up to 30 samples could be analysed in a single day. The method is reliable and can be used for screening of various HCAs. It has been applied to assess the concentrations of heterocyclic amines in otak-otak, a Malay-style grilled fish patty. The major mutagenic contaminant found in this foodstuff was 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2) (286-1068 micrograms/kg), followed by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (1.6-13.0 micrograms/kg) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (14.0-87.5 micrograms/kg). Two co-mutagens norharman (NH) and harman (H) were also detected in otak-otak at levels of 2.0-13.0 micrograms/kg and 12.8-21.3 micrograms/kg, respectively. The substantial amount of Glu-P-2 detected in otak-otak is probably a result of the ingredients used and the high temperature grilling process.