Purification and properties of phenylalanine ammonia-lyase from leaf mustard

Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5), the first enzyme in phenylpropanoid biosynthesis, catalyzes the elimination of ammonium ion from L-phenylalanine. In the present study, PAL was purified through ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 chromatography, and Q-Sepharose chromatography from the cytosolic fraction of leaf mustard (Brassica juncea var. integrifolia). It consists of 4 subunits, each having an estimated molecular weight of about 40,000 on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH and temperature of the purified enzyme are 9.0 and 45 degrees C, respectively. Its activity is inhibited by Zn2+ ion, and it is strongly activated by caffeic acid. The purified PAL seems to have some characteristics different from those obtained with other PALs.

Ischemia induces significant changes in purine nucleoside concentration in the retina-choroid in rats

Adenosine, produced from the decomposition of adenosine triphosphate, is believed to provide protective effects during ischemia. On the other hand, adenosine metabolites may serve as precursors for oxygen free radical formation. The time course of formation of adenosine and its purine metabolites was studied during retinal ischemia in rats. Concentrations of adenosine and its purine nucleoside metabolites inosine, hypoxanthine, and xanthine in the retina-choroid of ketamine/xylazine-anesthetized rats were measured during retinal ischemia using high performance liquid chromatography. Quantitative measurements were made possible in the small tissue mass through the use of internal standards. Ischemia was induced by ligation of the central retinal artery. In each rat, one eye was ischemic while the other served as a non-ischemic control. Eyes were frozen in situ at 1, 5, 10, 20, 30, 60, and 120 min of ischemia. The retina-choroid was then removed from the frozen eyes and analysed. Significant increases in the concentrations of adenosine, inosine, and hypoxanthine in ischemic compared to control retina-choroid were detectable within 1 to 5 min of the onset of ischemia, and within 10 min for xanthine. Increase in adenosine concentration in ischemic relative to control retina-choroid plateaued at 30 min of ischemia, while inosine and hypoxanthine concentrations increased continuously. The increase in xanthine concentration was exponential throughout the measurement period. This study documented the time-related changes in purine nucleoside concentration during ischemia. Prolonged ischemia results in ongoing production of xanthine, which by serving as a precursor for oxygen free radical formation, could be a pathogenic factor in prolonged retinal ischemia.

Adenosine receptor blockade and nitric oxide synthase inhibition in the retina: impact upon post-ischemic hyperemia and the electroretinogram

We preformed this study to determine the effect on ocular blood flow and the electroretinogram of either nitric oxide synthase (NOS) inhibition, adenosine receptor blockade or the combination of both after 1 hr of ocular ischemia. Thirty-seven cats under general anesthesia were subjected to 1 hr of complete ischemia in one eye by raising the intraocular pressure above systolic blood pressure. The other eye in each animal served as a non-ischemic control. Arterial blood gas tension, systemic arterial pressure, body temperature, hematocrit, and anesthetic level were controlled in each experiment. Cats were divided into four groups. Group 1 received normal saline injections [intravenous (i.v.) and intravitreal], Group 2 adenosine receptor blockade (0.1 ml of 0.01 M 8-sulfophenyltheophylline intravitreal) and saline i.v., Group 3 NOS inhibition (30 mg/kg l-NG-nitroarginine-methyl-ester i.v.) and saline intravitreal, and Group 4 intravitreal adenosine receptor blockade and NOS inhibition i.v. A subset of Group 3 received l-arginine to investigate the reversibility of NOS inhibition, after the blood flow measurements were completed. Five minutes after the end of ischemia, blood flows in retina and choroid were measured using injections of radioactively labeled microspheres. Electroretinographic (ERG) studies were carried out before treatment, before ischemia, during ischemia, and 1, 2, 3, and 4 hr after ischemia ended. NOS inhibition significantly reduced basal blood flow in the choroid, and in the retina when combined with adenosine receptor blockade. Adenosine receptor blockade completely attenuated post-ischemic hyperemia in the retina, but retinal hyperemia reappeared when adenosine receptor blockade and NOS inhibition were combined. Adenosine receptor blockade had no effect on ERG recovery after ischemia. NOS inhibition led to a reduction of ERG a- and b-wave amplitudes in control eyes, that could be reversed by l-arginine. Nitric oxide (NO) appears to be a significant factor in the regulation of basal blood flow in the choroid. Adenosine appears to be a major mediator of retinal hyperemia after 60 min of ischemia. Since NOS inhibition appeared to have direct effects on ERG wave amplitudes, short-term ERG studies may be of limited use in assessing the role of NO in postischemic recovery of the retina. Our observations correlate well with the emerging role of NO as a neurotransmitter in the retina.

The zygomatic-sphenoid fracture line in malar reduction. A cadaver study

OBJECTIVE

To demonstrate the persistent malar displacement and distraction of the zygomatic-sphenoid fracture line that is possible after alignment of the frontozygomatic and infraorbital rim fractures of a displaced malar fracture.

DESIGN

Nonblinded cadaver study.

SUBJECTS

Three fresh cadaver heads and 1 representative clinical example.

INTERVENTION

The cadaver heads were subjected to blunt trauma to the malar eminence. Reduction of the malar unit was performed either with attention to the frontozygomatic and infraorbital rim fractures alone or with concomitant inspection of the zygomatic-sphenoid fracture line. The representative case was repaired with a trans-conjunctival approach for inspection of the zygomatic-sphenoid fracture line.

RESULTS

Persistent malar asymmetry is possible after the reduction of displaced malar fractures when only the frontozygomatic and infraorbital rim buttresses are used for reference. In each case in our study, the zygomatic-sphenoid fracture line remained distracted. Alignment of the zygomatic-sphenoid fracture restored premorbid malar position.

CONCLUSION

Inspection of the zygomatic-sphenoid fracture line can contribute significantly to the precise 3-dimensional reduction of displaced malar fractures.

Effect of chronic administration of alcoholic beverages and seasoning containing alcohol on hepatic ethanol metabolism in mice

Five-week-old male mice, C3H/HeNCrj (C3H/He), were given a 5% (v/v) ethanol solution, commercial alcoholic beverages (Japanese sake (sake) or red wine) or a Japanese seasoning (mirin [containing ethanol and a large amount of glucose]) ad libitum for 45 d, and were then examined for changes in the hepatic enzymes related to ethanol metabolism 2 h after oral administration of 5 g of ethanol/kg body weight. The specific activity of aniline hydroxylase (ANH) in the hepatic microsome increased significantly in all groups chronically administered ethanol solution, sake, red wine or mirin, and the greatest increase was in the hepatic microsome of mirin-administered mice. The cytochrome P-450 (CYP) 2E1 increased in the hepatic microsome of the mice administered ethanol solution, red wine or mirin where accompanied by high ANH activity. The immunoreactive band for CYP1A1 showed high specificity in the microsome of mice given sake, red wine or mirin. It was assumed that CYP1A1 was induced by unknown component(s) other than ethanol in these solutions. In the cytosolic fraction, following the chronic administration of sake and mirin, the total aldehyde dehydrogenase (A1DH) activity with high-Km decreased significantly. In the mitochondrial fraction, the activity of high-Km A1DH increased significantly in the mirin-administered mice which drank a large amount of ethanol, whereas that in the red wine-administered group tended to decrease. These results indicate that the enzyme activities related to the oxidation of both ethanol and acetaldehyde in the cytosolic, mitochondrial and microsomal fractions of the liver were affected by either the action of ethanol or its interaction with other constituents of sake, red wine and mirin.

Isolation and characterization of the cDNA encoding the prophenoloxidase of fall webworm, hyphantria cunea

Two kinds of cDNA clones encoding prophenoloxidases (ProPO; zymogen of phenoloxidase (monophenol, L-dopa: oxygen oxydoreductase, EC 1.14.18.1)) were isolated by polymerase chain reaction (PCR) followed by screening of cDNA library that was prepared from whole larvae of the fall webworm, Hyphantria cunea (Lepidoptera, Arctiidae). The cDNAs encode 681 and 697 amino acids with molecular masses of 78.2 and 80.2 kDa, respectively. Deduced amino acid sequence homology between the two H. cunea ProPOs are only 49% whereas the homology against other insect ProPOs ranged from about 40 to 72%. The phylogenic analysis showed that the insect ProPOs are grouped mainly into two families. A putative proteolytic cleavage site for enzyme activation was identical to other insect ProPOs. The conserved copper binding sites were 84-62% homologous to arthropod ProPOs. Two additional highly conserved regions were found in the carboxy terminal. Furthermore, like other insect prophenoloxidases, hydrophobic signal peptide sequences were absent in the deduced ProPOs from H. cunea. Southern blot analysis indicated that the H. cunea ProPO1 is present as a single copy in the genome. Northern blot analysis showed that the expression of the ProPO genes were concentrated in mid-instar larvae, but were much lower in other developmental stages.

Reconstructive rhinoplasty

Reconstructive rhinoplasty for larger nasal defects requires a three-dimensional perspective using many of the aesthetic and functional techniques commonly employed in rhinoplasty. There are numerous ways of addressing a deficiency of the internal lining and each technique is detailed. Structural grafting is imperative in order to resist the contracture and collapse of the reconstructive nose. These grafts are also used to enhance contour and definition. Resurfacing of large cutaneous defects is frequently achieved through the midline forehead flap. There are many subtle maneuvers which can significantly impact the final aesthetic outcome and these are discussed below. This article highlights the three-layered approach to subtotal and total reconstructive rhinoplasty.

New approaches in clinical chemistry: on-line analyte concentration and microreaction capillary electrophoresis for the determination of drugs, metabolic intermediates, and biopolymers in biological fluids

The use of capillary electrophoresis (CE) for clinically relevant assays is attractive since it often presents many advantages over contemporary methods. The small-diameter tubing that holds the separation medium has led to the development of multicapillary instruments, and simultaneous sample analysis. Furthermore, CE is compatible with a wide range of detectors, including UV-Vis, fluorescence, laser-induced fluorescence, electrochemistry, mass spectrometry, radiometric, and more recently nuclear magnetic resonance, and laser-induced circular dichroism systems. Selection of an appropriate detector can yield highly specific analyte detection with good mass sensitivity. Another attractive feature of CE is the low consumption of sample and reagents. However, it is paradoxical that this advantage also leads to severe limitation, namely poor concentration sensitivity. Often high analyte concentrations are required in order to have injection of sufficient material for detection. In this regard, a series of devices that are broadly termed 'analyte concentrators' have been developed for analyte preconcentration on-line with the CE capillary. These devices have been used primarily for non-specific analyte preconcentration using packing material of the C18 type. Alternatively, the use of very specific antibody-containing cartridges and enzyme-immobilized microreactors have been demonstrated. In the current report, we review the likely impact of the technology of capillary electrophoresis and the role of the CE analyte concentrator-microreactor on the analysis of biomolecules, present on complex matrices, in a clinical laboratory. Specific examples of the direct analysis of physiologically-derived fluids and microdialysates are presented, and a personal view of the future of CE in the clinical environment is given.

Concentrations of adenosine and its metabolites in the rat retina/choroid during reperfusion after ischemia

PURPOSE

Little is known about the nature of biochemical disturbances during reperfusion after retinal ischemia. Previous studies have suggested that adenosine is responsible for regulation of retinal blood flow soon after ischemia has ended. Therefore, in this study we measured concentrations of adenosine and its metabolites in the rat retina/choroid after brief (10 min) or prolonged (60 min) periods of ischemia, and the functional consequences of inhibiting adenosine metabolism.

METHODS

Ischemia was produced in anesthetized rats by ligation of the central retinal artery. The eyes were frozen in situ and purine nucleoside concentration was determined by high performance liquid chromatography. The functional effects of pre-ischemic inhibition of xanthine dehydrogenase/xanthine oxidase were assessed by measurement of the electroretinogram before, during, and up to 7 days following 60 min ischemia.

RESULTS

Changes in the concentrations of adenosine and its metabolites were significant early in the reperfusion period, and were greater in magnitude and occurred earlier in prolonged, compared to brief, ischemic periods. Concentrations of adenosine, inosine, and hypoxanthine remained elevated for 30 min following the end of 60 min ischemia, and xanthine concentration was significantly elevated until 60 min after the end of either 10 or 60 min of ischemia. The onset of its peak value after ischemia was delayed in comparison to that of adenosine. Ischemia-evoked increases in xanthine concentration were attenuated by inhibition of adenosine deaminase or xanthine oxidase/xanthine dehydrogenase. Pre-ischemic inhibition of xanthine oxidase/xanthine dehydrogenase by oxypurinol (40 or 80 mg/kg intraperitoneally [IP]) resulted in a significant improvement in recovery of the a and b waves of the electroretinogram in comparison to a saline-treated control group.

CONCLUSIONS

These results indicate that adenosine is a major component of the biochemical changes that occur after retinal ischemia. Long-lasting increases in xanthine concentration during reperfusion after ischemia could be a source of oxygen free radicals that may contribute to delayed injury of the retina, attempts to decrease xanthine concentration would ideally be initiated within one hour after the end of ischemia.

Protein purification and cDNA cloning of a cecropin-like peptide from the larvae of fall webworm (Hyphantria cunea)

A proteinous antimicrobial substance was purified from the bacteria-challenged larvae of the fall webworm, Hyphantria cunea. It is a cecropin-like antibacterial peptide which exhibits antibacterial activity against Gram-negative and Gram-positive bacteria, and known as Hyphantria cecropin A. The cDNA clones corresponding to this peptide were isolated from a cDNA library constructed from the bacteria-challenged larvae and obtained complete nucleotide sequences. In addition to the Hyphantria cecropin A sequence, we obtained three other cDNAs exhibiting high sequence similarity with Hyphantria cecropin A. We synthesized the C-terminally amidated peptide of 35 residues based on the deduced sequence of the isolated cDNA of Hyphantria cecropin A. The synthetic peptide exhibited strong antibacterial activity against several microbes including medically important bacteria such as Salmonella, Shigella, and fungus such as Candida. A Southern blot experiment using these cloned cDNAs as probes predicted the existence of multiple forms of Hyphantria cecropin genes.

Pollen tube guidance by the female gametophyte

In flowering plants, pollen grains germinate on the pistil and send pollen tubes down the transmitting tract toward ovules. Previous genetic studies suggested that the ovule is responsible for long-range pollen tube guidance during the last phase of a pollen tube's journey to the female gametes. It was not possible, however, to unambiguously identify the signaling cells within an ovule: the haploid female gametophyte or the diploid sporophytic cells. In an effort to distinguish genetically between these two possibilities, we have used a reciprocal chromosomal translocation to generate flowers wherein approximately half the ovules do not contain a functional female gametophyte but all ovules contain genotypically normal sporophytic cells. In these flowers, pollen tubes are guided to the normal but not to the abnormal female gametophytes. These results strongly suggest that the female gametophyte is responsible for pollen tube guidance, but leave open the possibility that the gametophyte may accomplish this indirectly through its influence on some sporophytic cells.

Primary structure of 6.5k-arginine/glutamate-rich polypeptide from the seeds of sponge gourd (Luffa cylindrica)

The amino acid sequence of 6.5k-arginine/glutamate rich polypeptide (6.5k-AGRP) from the seeds of sponge gourd (Luffa cylindrica) has been determined. The 6.5k-AGRP consists of a 47-residue polypeptide chain containing two disulfide bonds, and a molecular mass calculated to be 5695 Da, which fully coincides with a value of [M+H]+ = m/zeta 5693.39 obtained by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). The mass spectrometric evidence indicated that 6.5k-AGRP is also present partially truncated at the C-terminus. In our preparations, approximately half of the polypeptide molecules have the C-terminal sequence Arg-Arg-Glu-Val-Asp; the other half lack Val-Asp and end with the glutamic acid, making a total of 45 residues in the polypeptide chain. The two disulfide bonds connect Cys12 to Cys33 and Cys16 to Cys29. Comparison of the amino acid sequence of 6.5k-AGRP with those of the other known proteins included in the PIR protein sequence database showed that it is related to the amino acid sequence of the N-terminal region encoded by the first exon of the cocoa (Theobroma cacao) and cotton seeds vicilin genes, sharing a characteristic two Cys-Xaa-Xaa-Xaa-Cys motif.

In vitro neutralization of hepatitis B virus by monoclonal antibodies against the viral surface antigen

In vitro HBV infection and neutralization were assayed using an anti-preS1 murine monoclonal antibody (1B3) and anti-preS2 (H69K) and anti-S (CS131A) murine-human chimeric antibodies. The 1B3 (IgG1) and H69K (IgG1) was constructed previously and the CS131A was constructed for this study by expressing stably the chimeric heavy and light chains in Chinese hamster ovary cells and purifying from the culture supernatant. Previous study showed that the H69K and CS131A recognize known virus-neutralizing epitopes, while the 1B3 does not. For the assays, adult human hepatocyte primary culture was infected with the adr or ayw subtype of HBV, and the infectivity and subsequent replication was confirmed both by measuring the kinetics of HB-sAg secretion by the infected cells and detecting the intermediate replicative form of HBV DNA in the cells. Next, the hepatocytes were infected with the adr or ayw subtype of the virus that had been preincubated with various concentrations of each of the antibodies and the neutralization of HBV was analyzed. The results showed that the anti-preS2 and anti-S chimeric antibodies exhibited neutralizing activity against both the adr and ayw subtypes of the virus, with approximately 1,000 and 2,000 times higher specific activity than polyclonal hepatitis B immune globulin, respectively, but the anti-preS1 antibody scarcely neutralized the infection. The neutralizing activities of the antibodies were consistent with their epitope specificity and antigenbinding affinity, suggesting that this neutralization assay is specific. The in vitro neutralization assay will be useful for evaluating the neutralizing activity of anti-HBV antibodies before in vivo testing in chimpanzees.

Role of cytochrome P450 enzyme induction in the metabolic activation of benzo[c]phenanthrene in human cell lines and mouse epidermis

The environmental contaminant benzo[c]phenanthrene (B[c]Ph) has weak carcinogenic activity in rodent bioassays; however, the fjord region diol epoxides of B[c]Ph, B[c]Ph-3,4-diol 1,2-epoxides (B[c]PhDE), are potent carcinogens. To determine the role of cytochrome P450 isozymes in the activation of B[c]Ph in MCF-7 cells and the low activation of B[c]Ph in mouse skin, cells of the MCF-7 and the human hepatoma HepG2 cell lines were treated with the potent Ah receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) prior to exposure to B[c]Ph for 24 h. Mice were treated topically with 1 microg of TCDD or vehicle (control) for 73 h and then with 2 micromol of B[c]Ph for 24 h. In MCF-7 cells, TCDD exposure increased B[c]PhDE-DNA adduct levels more than 3-fold with a 10-fold increase in the (-)-B[c]PhDE-2-dA(t) adduct. Treatment of HepG2 cells with TCDD prior to B[c]Ph application did not increase B[c]PhDE-DNA binding. Total B[c]PhDE-DNA adducts increased 3-fold in TCDD-treated mouse epidermis: the majority of the increase resulted from (+)-B[c]PhDE-1-dA adducts. Analysis of P450 enzymes by Western blotting detected a large increase of P4501B1 but almost no increase in P4501A1 in MCF-7 cells exposed to 10 microM B[c]Ph for 24 or 48 h. In HepG2 cells, there were no detectable levels of P4501A1 or P4501B1 after treatment with 10 microM B[c]Ph for 24 h. In contrast, topical application of 2 micromol of B[c]Ph to mouse skin for 48 or 72 h increased P4501A1, but no P4501B1 was detected. As a measure of P450 activity, the metabolism of 7,12-dimethylbenz[a]anthracene (DMBA) was analyzed in microsomes prepared from MCF-7 and HepG2 cells exposed to 0.1% DMSO, 10 microM B[c]Ph, or 10 nM TCDD for 24 or 48 h and from mouse epidermis treated with 1 microg of TCDD, or vehicle control for 72 h, or 2 micromol of B[c]Ph for 48 h. The levels of DMBA metabolites were low or undetectable in microsomes from B[c]Ph-treated MCF-7 and HepG2 cells, but a metabolite pattern consistent with P4501A1 metabolism of DMBA was present in B[c]Ph-exposed mouse epidermal microsomes. TCDD-treated MCF-7 cells, HepG2 cells, and mouse epidermis had DMBA metabolism patterns characteristic of P4501A1 activity. Microsomes from TCDD-treated human cells formed a higher proportion of the proximate carcinogenic metabolite DMBA-3,4-dihydrodiol (16% of total identified metabolites) than TCDD-treated mouse epidermis (2%). In mouse epidermis, the weak ability of B[c]Ph to increase hydrocarbon-metabolizing activity and the increase in mainly P4501A1, leading to formation of the less carcinogenic stereoisomer B[c]PhDE-1, may explain the low carcinogenic activity of B[c]Ph. In a human mammary carcinoma cell line, treatment with B[c]Ph increases mainly P4501B1 and results in formation of a higher proportion of the more carcinogenic B[c]PhDE-2. This indicates that cells in which B[c]Ph treatment increases P4501B1 levels effectively activate B[c]Ph to potent carcinogenic metabolites.

Catalysis of the cysteine conjugation and protein binding of acetaminophen by microsomes from a human lymphoblast line transfected with the cDNAs of various forms of human cytochrome P450

We have previously found that for acetaminophen kinetic differences exist between the hepatic microsomal catalyzed protein binding and cysteine conjugation. We have also observed that the protein binding of acetaminophen is only to intralumenal proteins. Together these data suggested that two pools of the reactive metabolite, N-acetyl-p-benzoquinone imine (NABQI), are formed during the oxidative metabolism of acetaminophen: one on the cytosolic surface and the other within the lumen of the microsomes. This would indicate that some of forms of cytochrome P450 (CYP) catalyzing NABQI formation have their active site on the cytosolic surface and others on the lumenal surface. We have examined this question by comparing the rates of cysteine conjugation and protein binding of acetaminophen by microsomes from lymphoblasts transfected with the cDNAs for human CYPs. We found that CYP2D6 catalyzed only cysteine conjugation; CYP1A2 and 3A4 catalyzed only protein binding; CYP2E1 catalyzed both; and CYP1A1, CYP2A6 and CYP2B6 catalyzed neither. These data suggest that CYP2D6 has its active site only on the cytosolic surface; CYP1A2 and CYP3A4 only on the lumenal surface; and CYP2E1 has catalytic sites on both the lumenal and cytosolic surfaces of the membrane. In mouse studies we have found that ethanol administration increased acetaminophen protein binding by 265% but cysteine conjugation by only 61%. CYP2E1 and CYP2B increased, whereas CYP3A decreased and the others did not change. These data suggest that in control mice CYP2E1 catalyzes the bulk of protein binding, whereas CYP2D catalyzes slightly more cysteine conjugation than does CYP2E1.

Cartilage Viability with Interpolated Skin Flaps: An Experimental Study

Although composite cartilage grafts are often used in conjunction with a midline forehead flap to repair full-thickness nasal defects, the timing of pedicle division, which optimizes cartilage viability, has yet to be determined. A rabbit animal model was designed to investigate this question. The skin flap pedicle was divided at 0 days, 4 days, 3 weeks, 6 weeks, and 10 weeks in each of five groups of five animals. Although early pedicle division led to partial skin flap necrosis, the cartilage grafts tolerated this ischemic period better. Cartilage viability was approximately 70% and did not differ significantly between the five groups. It is concluded that a larger composite graft and better definition of the skin flap's critical period are needed to determine optimum timing for pedicle division in this animal model.

Cartilage viability with interpolated skin flaps: an experimental study

Although composite cartilage grafts are often used in conjunction with a midline forehead flap to repair full-thickness nasal defects, the timing of pedicle division, which optimizes cartilage viability, has yet to be determined. A rabbit animal model was designed to investigate this question. The skin flap pedicle was divided at 0 days, 4 days, 3 weeks, 6 weeks, and 10 weeks in each of five groups of five animals. Although early pedicle division led to partial skin flap necrosis, the cartilage grafts tolerated this ischemic period better. Cartilage viability was approximately 70% and did not differ significantly between the five groups. It is concluded that a larger composite graft and better definition of the skin flap's critical period are needed to determine optimum timing for pedicle division in this animal model.

Primary structure and allergenic activity of trypsin inhibitors from the seeds of buckwheat (Fagopyrum esculentum Moench)

The complete amino acid sequences of two trypsin inhibitors BWI-2a and BWI-2b from the seeds of buckwheat (Fagopyrum esculentum Moench) were determined. BWI-2b consists of 51 amino acid residues containing two disulfide bonds. BWI-2a shares all amino acids with BWI-2b except for the C-terminal tripeptide: BWI-2a lacks Glu-Gly-Asn and ends with the Asp residue, making a total of 48 residues in the chain. The two disulfide bonds connect Cys11 to Cys32 and Cys15 to Cys28. BWI-2b shows no relatedness to the other buckwheat trypsin inhibitor reported [Belozersky et al. (1995) FEBS Lett. 371, 264-266]. Sequence comparison of BWI-2b with those of the other proteins included in PIR showed that BWI-2b is significantly homologous to the N-terminal region of storage proteins classified in the vicilin family. Furthermore, the allergenic activity of BWI-2b and the other buckwheat trypsin inhibitor BWI-1 was examined using the radioallergosorbent test. The result indicated that both inhibitors BWI-2b and BWI-1 have IgE binding activity, albeit to a low extent, suggesting that they might be minor allergenic proteins in buckwheat seeds.

Magnetic resonance imaging in hemospermia

PURPOSE

We evaluated the prostate and seminal tract with magnetic resonance imaging (MRI) in patients with hemospermia.

MATERIALS AND METHODS

To evaluate the prostate and seminal tract in 17 patients 20 to 59 years old (mean age 44) with hemospermia we performed transrectal ultrasound and MRI using an endorectal surface coil with a 1.5 tesla unit. Mean duration of hemospermia was 32 months (1 week to 16 years).

RESULTS

Abnormalities were noted on transrectal ultrasound in 15 of the 17 patients (88%) and on MRI in all. Of the 12 cases of hemorrhage 10 involved the seminal vesicle and 2 involved the ejaculatory duct. There were 12 cystic lesions, including 7 in the müllerian and 5 in the ejaculatory ducts. Of 19 cases calculi were detected in the prostate in 5, seminal vesicle in 8, and ejaculatory and müllerian duct cysts in 4 and 2, respectively. There was 1 case of prostatic atrophy and 1 wolffian duct anomaly associated with an ejaculatory duct cyst, ectopic ureterocele and absence of the left kidney.

CONCLUSIONS

MRI with an endorectal surface coil is a powerful modality for evaluating the seminal tracts of patients with hemospermia. It can be performed clinically when transrectal ultrasonography is not satisfactory.

Protein purification and nucleotide sequence of a lysozyme from the bacteria-induced larvae of the fall webworm, Hyphantria cunea

A protein with lytic activity against Micrococcus luteus was purified from the hemolymph of the fall webworm, Hyphantria cunea, larvae challenged with live E. coli. A bacteriolytic protein of about 14,000 daltons in mass was purified by cation exchange chromatography and reverse-phased HPLC. The optimum pH and optimum temperature range for activity were around pH 6.2 and 50 degrees C, respectively, in a 100 mM phosphate buffer. The amino-terminal amino acid sequence of this protein was determined and the corresponding cDNA was isolated and analyzed. The deduced protein of 142 amino acid residues was composed of a putative leader sequence of 20 residues and the mature enzyme of 122 residues. The cloned lysozyme gene was strongly induced in response to bacterial injection, implying that the enzyme is a part of the immune response of H. cunea. Comparison with other known lysozyme sequences shows that our lysozyme belongs to the chicken lysozyme.

Generation and characterization of a humanized antibody with specificity for preS2 surface antigen of hepatitis B virus

For the prevention of hepatitis B virus (HBV) infection, monoclonal antibodies (mAbs) against the surface antigens of HBV would offer several advantages over the current human polyclonal antibody. We have developed a humanized antibody with specificity for the preS2 surface antigen of HBV and evaluated the neutralizing activity of the humanized antibody. The complementarity-determining regions of the heavy and light chains of a murine monoclonal antibody (H8) were grafted onto the variable regions of a highly homologous human anti-Sm antibody, which were then combined with the constant regions of human gamma 1 and kappa, respectively. The affinity of the resulting humanized antibody (Z6B) was about one tenth that of the chimeric antibody. The new version (ZP39) of the humanized antibody, which was constructed by substituting the heavy-chain framework residue at position 94 of the Z6B with original mouse residue, showed almost the same affinity as that of the chimeric antibody. The evaluation of the HBV neutralizing activity of ZP39 using in vitro infection of adult human hepatocyte primary culture by HBV showed that it had a specific activity that was approximately 1000 times higher than commercially available polyclonal hepatitis B immune globulin. We expect that the present humanized antibody will be useful in the prevention of HBV infection.

The liposhaver in facial plastic surgery. A multi-institutional experience

OBJECTIVE

To report a multi-institutional clinical experience with the liposhaver in facial plastic surgery.

DESIGN

Nonrandomized, nonblinded, multi-institutional evaluation of the liposhaver in a clinical setting in patients presenting for cosmetic facial liposuction.

INTERVENTIONS

Cosmetic facial surgery with the liposhaver was performed in 19 patients (21 procedures) who underwent submental lipectomy, facelift with defatting beneath the facelift flap, and/or correction of deep nasolabial folds. Standardized preoperative and postoperative photographs were obtained. Fat obtained from the abdomen of 1 patient was also studied histologically. This fat was excised sharply and was then liposhaved at varying oscillation speeds.

OUTCOME MEASURES

Subjective evaluation by the operating surgeons.

RESULTS

The liposhaver was used successfully in all cases. The fat was cleanly shaved and the contour results were even, without dimpling or asymmetry. Operative time was comparable to that for conventional liposuction. Preferred cannula sizes and settings were determined. There were no cases of facial nerve injury, no evidence of increased bleeding intraoperatively, and no hematomas in the immediate postoperative period. One patient developed a small hematoma on postoperative day 5 that was effectively treated with needle aspiration and a pressure dressing. Histologic evaluation of liposhaved abdominal fat showed normal fat cells and well-preserved architecture.

CONCLUSIONS

The liposhaver offers a precise alterative to conventional liposuction. It may be less traumatic because it requires low suction pressures and does not rely on the potentially bruising, vigorous, back-and-forth motion for fat extraction typical of conventional liposuction.

Measurement of purine nucleoside concentration in the intact rat retina

Adenosine, produced from the decomposition of adenosine triphosphate, is believed to provide protective effects during ischemia. On the other hand, adenosine metabolites may serve as precursors for oxygen free radical formation. These substances have not been previously measured in intact vertebrate retina, where adenosine and its metabolites may play a role in the pathogenesis of ischemic injury. The small tissue mass of the retina, particularly in rats, renders these measurements challenging. Furthermore, accurate measurement of purine nucleosides requires immediate cessation of ongoing adenosine metabolism. Concentrations of adenosine and its purine nucleoside metabolites inosine, hypoxanthine, and xanthine in the retina of ketamine/xylazine-anesthetized rats were measured after in situ freezing using high-performance liquid chromatography. The retina was removed from the frozen eyes and analyzed. Quantitative measurements were made possible through the use of an internal standard. Ischemia was induced by ligation of the central retinal artery. Retinal purine nucleoside concentrations did not differ between the two eyes of the rat under control conditions, and there was no effect of placement of the ligating suture itself compared to completely unmanipulated eyes. Use of two different in situ freezing methods yielded comparable results. To evaluate the impact of a period of ischemia, one retina of each rat was ischemic for 30 min, and the other, non-ischemic. Our measurements were associated with a high degree of reproducibility and minimal variability, and significant changes in purine nucleoside concentrations were detectable in the retina after 30 min of ischemia. Our method may be used to assess the role of adenosine and its metabolites in the pathogenesis of ischemic neuronal injury, including in the retina.

Metabolism of phenytoin by the gingiva of normal humans: the possible role of reactive metabolites of phenytoin in the initiation of gingival hyperplasia

Gingival hyperplasia is a well-known complication of therapy with cyclosporine, calcium channel blockers, and phenytoin. It is characterized by the presence of inflammation and a marked fibrotic response. The mechanism of this adverse reaction is unknown. We propose that it may be initiated by the metabolic activation of these drugs to form reactive metabolites. These then cause cellular injury and lead to the gingival hyperplasia. To evaluate this hypothesis we examined phenytoin metabolism and the cytochrome P450 contents of gingival tissues from 10 patients undergoing surgery for various periodontal conditions. We found that microsomes obtained from the gingiva show significant phenytoin hydroxylase activity as determined by the production of 5-(4'-hydroxyphenyl)-5-phenylhydantoin (HPPH) (range, 12.8 pmol HPPH/min.mg microsomal protein to 276.9 pmol HPPH/min.mg microsomal protein; rat control, 133.7 +/- 11.5 pmol HPPH/min.mg microsomal protein). We also found that CYP1A1, CYP1A2, CYP2C9, CYP2E1, and CYP3A4 were present in these microsomes. We detected no CYP2B6 or CYP2D6. We believe that these data support our hypothesis that the proliferative inflammation observed with drugs such as phenytoin, nifedipine, and cyclosporine may be initiated by the formation of reactive metabolites and that the formation of these metabolites may be catalyzed by one or more CYPs found in the gingiva. These metabolites may then cause cellular injury and induce a reactive inflammatory response, followed by fibroblastic proliferation. This proliferation leads to the excess collagen deposition observed with gingival hyperplasia.

Role of ischemic gradient in neovascularization of interpolated skin flaps

OBJECTIVES

To investigate the significance of the ischemic gradient between interpolated skin flaps and the recipient bed and to determine its role in flap viability.

DESIGN

Bilateral interpolated skin flaps were elevated in 10 pigs and intravenous fluorescein was used to define a border of pedicle perfusion. Flaps were assigned to 1 of 2 groups: proximal flaps, which were contained within the fluorescein border, or distal flaps, which extended 3 cm beyond the fluorescein border. Flaps were then transferred to an adjacent cutaneous defect and pedicles were divided after 2 weeks. The flap and pedicle portions were evaluated separately and viability was quantified.

SUBJECTS

Ten adolescent pigs with bilateral flaps. None were withdrawn.

INTERVENTION

Intravenous fluorescein (20 mg/kg) to determine extent of perfusion in the flaps.

RESULTS

Proximal flaps (n = 10) maintained excellent viability with the pedicles attached. After pedicle division, however, partial flap and pedicle necrosis developed. Distal flaps (n = 10) promptly showed signs of ischemia and congestion but soon showed improved vascularity. A statistically significant improvement was seen in mean percent viability of the distal group compared with the proximal group (P < .05) (Student t test).

CONCLUSION

The more ischemic flap-pedicle complex resulted in greater viability after pedicle division. The ischemic gradient seemed to represent a potent angiogenic stimulus to the recipient bed.

Effect of transforming growth factor-beta on plasminogen activator production of cultured human uveal melanoma cells

PURPOSE

Human uveal melanoma cells have been shown to produce plasminogen activator (PA), an enzyme which can enhance tumor metastasis by promoting degradation of extracellular matrix. This study used cultured human uveal melanoma cells to determine whether the PA production of uveal melanoma cells could be modulated by transforming growth factor-beta2 (TGF-beta2), a mitogen present in the uvea.

METHODS

Five different cell lines of human uveal melanoma of differing cellular morphology (2 spindle, 2 epithelioid, 1 mixed) derived from tumors from different locations in the eye (3 choroidal, 1 ciliochoroidal, 1 orbital) were grown in serum-free media, in the presence or absence of TGF-beta2 (1ng/ml to 100ng/ml). After 24 hrs, the conditioned media were collected and quantitated for PA activity by measuring the radial diffusion in fibrin-agarose clot and for total PA concentration using an enzyme-linked immunoassay.

RESULTS

Among the cell lines studied, all produced PA. Cell lines derived from intraocular tumors secreted tissue-type PA (tPA), and TGF-beta2 stimulated tPA activity and secretion of cell lines containing epithelioid cells but had no effect on spindle cells. In contrast, tumor cells isolated from an orbital tumor secreted urokinase (uPA), activity and secretion of which was inhibited by TGF-beta2.

CONCLUSIONS

We conclude that cultured human uveal melanoma cells produce either tPA or uPA, and TGF-beta2 can have a variable effect on PA production of these cells.

CYP2E1-dependent bioactivation of 1,1-dichloroethylene in murine lung: formation of reactive intermediates and glutathione conjugates

We investigated the cytochrome P450-dependent metabolism of 1,1-dichloroethylene (DCE) in murine lung microsomal incubations. The metabolites were identified as their glutathione conjugates or hydrolyzed products, analyzed by HPLC and quantified with [14C]DCE. We determined the relative quantities of DICE metabolites formed in lung microsomal incubations and compared them to those produced in liver. Furthermore, we used antibody inhibition experiments to investigate the CYP2E1-dependent metabolism of DCE in lung. Our results demonstrated that reactive intermediates were generated from DCE in the lung microsomal incubations. The DCE epoxide (12.6 +/- 1.4 pmol/mg protein/min) was the major metabolite formed and was identified as two glutathione conjugates, 2-(S-glutathionyl) acetyl glutathione and 2-S-glutathionyl acetate. Lower levels of the acetal of 2,2-dichloroacetaldehyde (3.6 +/- 0.25 pmol/mg protein/min) were detected. The ratio of acetal to DCE epoxide was higher in lung (0.30 +/- 0.04) than in liver (0.12 +/- 0.02). Preincubation of microsomes with a CYP2E1-inhibitory monoclonal antibody resulted in a maximum inhibition of 50% in the formation of both the acetal and the glutathione conjugates derived from the DCE epoxide. These data demonstrated that lung CYP2E1 metabolizes DCE to reactive intermediates of which the DCE epoxide is both the major metabolite formed and an efficient scavenger of glutathione, implicating it as an important toxic species mediating DCE-induced lung cytotoxicity.

Effects of nitric oxide (NO) synthesis inhibition on antitumor responses during interleukin-2 (IL-2) treatment of mice

OBJECTIVES

To evaluate if L-arginine: NO pathway is activated in tumor tissues during IL-2 therapy and to evaluate whether IL-2 induced NO synthesis represents an antitumor effector mechanism or an inhibitory factor against therapeutic effects of IL-2.

METHODS

Four groups [untreated control, NG-monomethyl-L-arginine (MLA) therapy only, IL-2 therapy only, IL-2/MLA therapy groups] of BALB/c mice were injected intraperitoneally with 2 x 10(8) Meth A tumor cells on day 0. MLA was administered subcutaneously with Alzet continuous infusion pumps on day 2. IL-2 therapy (180,000 IU s.c. every 12h for 5 days) was started on day 3. NO production within ascites tumors was assessed by measuring nitrite concentrations in cultures of ascites cells harvested on day 8. Survival and the rate of body weight increment of the mice were measured to evaluate therapeutic responses. Daily urinary nitrate excretion was monitored to demonstrate the effectiveness of MLA in inhibiting NO synthesis.

RESULTS

Nitrite production in supernatants of Meth A ascites cell cultures was 63 +/- 14 microM in IL-2 treated mice and 3.2 +/- 1.5 microM in untreated controls (p < 0.001). MLA prevented the IL-2 therapy induced increase in nitrite production. IL-2 therapy did not decrease the rate of body weight increment and marginally prolonged mean survival to 18.2 days, compared to 16.6 days in control mice (p = 0.255). MLA administration decreased the rate of body weight increment and prolonged mean survival of IL-2 treated mice (21.8 days, p = 0.001 versus IL-2 alone). Interestingly, the MLA treatment increased the rate of body weight increment and diminished the survival of control mice to 11.6 days (p = 0.003). MLA administration via Alzet continuous infusion pumps achieved approximately 60% suppression of urinary nitrate excretion by control mice. Subcutaneous IL-2 treatment strongly induced nitric oxide synthesis (up to 3.5 mumoles of urinary nitrate/ mouse/day). MLA also effectively suppressed IL-2 induced NO production.

CONCLUSION

L-arginine: NO pathway can be activated in malignant ascites by IL-2 therapy and NO synthesis functions as an inhibitory mechanism against IL-2 induced anti-tumor effects.

Immunosuppression induced by acute exposure to cocaine is dependent on metabolism by cytochrome P-450

The primary objective of this paper was to characterize the role of metabolism in immunosuppression by acute exposure to cocaine. beta-Ionone has been used to study the role of metabolism in hepatotoxicity associated with acute exposure to cocaine, and was shown to produce a greater effect than other cytochrome P-450 (P-450) inducers. When beta-ionone (600 mg/kg s.c.) was pretreated 72 and 48 hr before the acute administration of cocaine (30 mg/kg i.p.) in B6C3F1 female mice, the antibody response to sheep red blood cells was significantly suppressed. Exposure to cocaine alone produced little or no suppression. The immunosuppression in cocaine + beta-ionone-treated mice was accompanied by a decrease in thymus weight and an increase in liver weight. Administration of metyrapone (40 mg/kg i.p.) 30 min before cocaine administration (40 mg/kg) blocked completely the suppression of the antibody response by cocaine in beta-ionone-pretreated mice. The reversal by metyrapone was additional evidence that a P-450 pathway was the critical metabolic pathway of cocaine to be immunosuppressive, and the inhibitory effect of metyrapone on cocaine N-demethylase was confirmed in liver microsomes. The inductive effects of beta-ionone were also characterized further. Cocaine N-demethylase activity was significantly induced by beta-ionone. The induction of P-450IIB1/2, the only isozyme shown previously to be associated with the hepatotoxicity by cocaine, was demonstrated by Western immunoblotting to be induced by beta-ionone at doses as low as 300 mg/kg; but was less than the induction associated with phenobarbital. Studies confirmed that acute exposure to cocaine also was immunosuppressive in phenobarbital-pretreated mice. Taken together, our present results suggest that the immunosuppression by acute exposure to cocaine is associated with the increased metabolism of cocaine to toxic metabolites by P-450, probably P-450IIB1/2, as demonstrated previously for its hepatotoxicity.

Induction and suppression of renal and hepatic cytochrome P450-dependent monooxygenases by acute and chronic streptozotocin diabetes in hamsters

The acute and chronic effects of streptozotocin diabetes on kidney and liver microsomal monooxygenases were studied using hamsters 2 days and 6 weeks following treatment with the diabetogen, respectively. Acute diabetes increased aniline hydroxylation and N-nitrosodimethylamine demethylation, decreased pentoxyresorufin O-dealkylation, without affecting benzo(a)pyrene hydroxylation and 7-ethoxycoumarin O-deethylation in kidney and liver microsomes. The effects of chronic diabetes on the microsomal monooxygenases were similar to the effects of acute diabetes, except that the chronic diabetic condition markedly decreased benzo(a)pyrene and 7-ethoxycoumarin oxidations in kidney microsomes. Total cytochrome P450 content and NADPH-cytochrome P450 reductase activity in kidney and liver microsomes of the diabetic hamsters were similar to the controls. Gel electrophoresis of microsomes from control and streptozoptocin treated hamster tissues revealed that diabetes enhanced the intensity of protein band(s) in the P450 molecular weight region. Immunoblotting of microsomal proteins showed that acute and chronic streptozotocin diabetes induced proteins immunorelated to P450s 2E1 and 1A in kidney and liver. In marked contrast, the acute and chronic diabetic conditions decreased the level of a P450 2B-immunorelated protein(s) in kidney and liver. The present study demonstrates that acute and chronic streptozotocin diabetes has the ability to induce P450 2E1 and 1A and suppress P450 2B in hamster kidney and liver and that the hamster monooxygenase responds to diabetes differently from the rat enzyme.

Visual-field deficits associated with proton beam irradiation for parapapillary choroidal melanoma

PURPOSE

A large series of patients treated with proton irradiation for parapapillary choroidal melanoma were reviewed retrospectively to determine the frequency of radiation papillopathy and visual-field loss after treatment.

METHODS

Among 249 patients with proton irradiation for parapapillary choroidal melanoma, the authors identified 59 patients who had visual-field testing performed before treatment and at least 18 months after treatment. The visual fields, color fundus photographs, and charts were reviewed to determine the prevalence of radiation papillopathy and visual-field loss after treatment.

RESULTS

Nineteen of the 59 patients reviewed (31%) received a clinical diagnosis of radiation papillopathy. Progressive visual-field loss, defined as enlargement of absolute scotoma of greater than [corrected] or equal to 30 degrees as compared with the pretreatment visual field, was noted in 67% of patients with radiation papillopathy and 73% of patients without papillopathy. In both groups, visual-field loss correlated with the area of the retina predicted to be exposed to irradiation in the majority of patients.

CONCLUSIONS

Progressive visual-field loss is common after proton irradiation for parapapillary choroidal melanoma. However, the scotoma usually correlates with the area of the retina exposed to irradiation. The development of radiation papillopathy does not appear to be associated with additional visual-field defects in most cases.

Immunohistochemical properties of dipyrone-induced cytochromes P450 in rats

1. Rat hepatic cytochrome P450s induced by dipyrone were studied enzymatically, immunochemically and immunohistochemically. 2. Dipyrone administered to male Wistar rats increased pentoxyresorufin O-depentylation (PROD), ethoxyresorufin O-deethylation (EROD) and 7-ethoxycoumarin O-deethylation (ECOD) activities up to 44-, 1.9-, and 2.6-fold, respectively. Aryl hydrocarbon hydroxylase (AHH) activity was not affected. 3. Immunoinhibition with the monoclonal antibody (Mab) 2-66-3 (to CYP2B1/2) markedly decreased PROD and EROD activities, but not AHH activity. The Mab 1-7-1 (to CYP1A1/2) was without effect. 4. Histochemically, the Mab 2-66-3 gave a strong and uniform staining in livers from dipyrone-treated rats, whereas the Mab 1-7-1 gave a positive reaction in a narrow perivenous strip. 5. The induction pattern as well as inhibition by the Mabs convincingly demonstrate the predominant production of CYP2B1/2 in the induction spectrum of dipyrone. The increase in enzyme activities other than PROD may be due to the overlapping substrate specificity of CYP2B1/2 enzymes. The immunohistochemical analysis also indicated the participation of CYP1A1/2.

Ethanol induces CYP2E1 by protein stabilization. Role of ubiquitin conjugation in the rapid degradation of CYP2E1

In the present study, we demonstrate that ethanol induces CYP2E1 by protein stabilization in vivo. The control half-life of CYP2E1 was determined to be 6-7 h followed by a slower secondary phase. The half-life of ethanol-stabilized CYP2E1 was calculated to be 38 h. The mechanism underlying the rapid degradation of CYP2E1 was also investigated and appears to involve the ubiquitin-proteasome proteolytic pathway. An in vitro assay using the cytosolic fraction was developed to further characterize CYP2E1 degradation. Using this assay, 40-50% loss of CYP2E1 was observed in 1 h, coincident with the formation of high M(r) ubiquitin-CYP2E1 conjugates. At concentrations approximating those found in vivo, ethanol protects CYP2E1 from cytosolic degradation. No loss of CYP2B1/2 was observed under identical conditions, suggesting that this reaction is specific for certain P-450s which are rapidly turned over.

The soft-tissue shaving procedure for removal of adipose tissue. A new, less traumatic approach than liposuction

OBJECTIVE

To introduce the soft-tissue shaving cannula, a new, precise alternative to conventional liposuction that embodies an entirely different method of soft-tissue extraction and that appears to be less traumatic and more precise than methods currently used in liposuction.

DESIGN

Nonrandomized, nonblinded comparison of the soft-tissue shaver and conventional liposuction devices in fresh cadavers, followed by clinical use of the liposhaver in selected patients undergoing cosmetic facial liposuction.

INTERVENTIONS

Conventional liposuction devices and the soft-tissue shaving cannulas in fresh cadavers (< 8 hours old). A submental lipectomy and a melolabial fold liposhaving were performed in a clinical setting.

OUTCOME MEASURES

Subjective evaluation by the operating surgeons.

RESULTS

The fat was cleanly shaved and the contour result was even, without dimpling or asymmetry.

CONCLUSIONS

Our early experiences suggest that this new liposhaving technique may offer a precise, less traumatic alternative to conventional liposuction. Fat can be shaved in an open fashion under direct vision. It does not rely on a vacuum seal. The soft-tissue shaving cannula shaves fat one layer at a time. The depth of each layer removed, the depth of soft-tissue injury, and the optimal settings and sizes for various procedures remain to be reported.

Tissue-engineered cartilage for implantation and grafting

Facial plastic and reconstructive surgeons are continually faced with the dilemma of what material to use for implantation and grafting. Tissue-engineered cartilage is a relatively new and exciting concept which utilizes chondrocytes and cultures them on a three-dimensional biodegradable template. This template/cell complex is first briefly incubated in vitro, then implanted into a recipient host. In situ the template resorbs and is replaced with new cartilage that is viable, compatible, and mature. This paper discusses the biochemical composition of cartilage, the concept of tissue engineering, advances in template quality, and cartilage immunogenicity. Future clinical applications of this type of graft research include microtia repair, facial reconstruction, rhinoplasty, and other facial cosmetic procedures.

The epithelial 'turn-in' flap in nasal reconstruction

OBJECTIVES

To evaluate the epithelial "turn-in" flap for reconstruction of the internal lining in full-thickness nasal defects. Highlighted are its indications, technique, complications, and clinical success, particularly in comparison with the other common modalities for reconstructing this nasal lining. Also, to determine how the random flap withstands vigorous thinning.

DESIGN

A retrospective chart review and clinical follow-up of all patients with full-thickness nasal defects of the nose.

SETTING

The patient pool comes from a tertiary care center that draws from a large geographic area in the Northwest. Both urban and rural demographics are represented.

PATIENTS

Fifty-six patients with large full-thickness nasal defects were reviewed, 18 of which were reconstructed with the epithelial turn-in flap. The causes of the original defect were varied.

INTERVENTION

Full-thickness nasal defects were reconstructed in a layered fashion. The turn-in flaps were aggressively thinned to the subdermal plane to minimize flap bulk and airway compromise.

MAIN OUTCOME MEASURES

Attention was made to the size and precise location of the defect, the mode of reconstruction, flap viability, and nasal function.

RESULTS

Eighteen patients had turn-in flaps for reconstruction of the internal lining. Sixteen patients (89%) had 100% viability of their flaps. Seventeen (94%) reported normal nasal function.

CONCLUSIONS

The epithelial turn-in flap is a robust flap that provides dependable and functional results. One of the major advantages of this flap over other methods is that often there is no donor site morbidity. For many select defects, the turn-in flap remains a method of choice for repair of the internal lining.

Effect of intravitreal dexamethasone in treatment of pneumococcal endophthalmitis in rabbits

PURPOSE

To investigate whether corticosteroid therapy would decrease the inflammation and tissue damage associated with pneumococcal endophthalmitis.

METHODS

Albino rabbits were injected intravitreally with 1000 live organisms of Streptococcus pneumoniae and randomized after 24 hours to treatment with intravitreal vancomycin hydrochloride alone (n = 10), combination intravitreal vancomycin and intravitreal dexamethasone (n = 10), or no treatment (n = 10). After 2 weeks, the eyes were examined clinically and enucleated for histopathologic examination.

RESULTS

Eyes treated with vancomycin and dexamethasone had significantly less intraocular inflammation and more preservation of retinal tissue than untreated eyes or eyes treated with vancomycin alone (P < .05, Fisher's exact test). Untreated and vancomycin-treated eyes were indistinguishable on clinical and histologic examination. Marked anterior and posterior segment inflammation with total retinal necrosis was noted in eyes from both groups.

CONCLUSION

Intravitreal corticosteroid therapy may play an important role in minimizing the inflammation and tissue damage associated with pneumococcal endophthalmitis.

Inhibition of benzo[a]pyrene metabolism by insulin, FITC-insulin and an FITC-insulin-antibody conjugate in the human hepatoma cell line HepG2

Benzo[a]pyrene (BaP) can be metabolically activated to an ultimate carcinogen, (+)-anti-BaP-7,8-dihydrodiol-9,10-epoxide [(+)-anti-BaPDE] by cells in culture. This activation involves oxidation by specific isoforms of cytochrome P450s such as CYP1A1. The human hepatoma cell line, HepG2, was used to examine the effect of inhibition of CYP1A1 activity by anti CYP1A1 specific antibodies on BaP metabolism. Metabolism of BaP to water-soluble metabolites by HepG2 cells in culture was 50% lower in fluorescein isothiocyanate (FITC)-insulin-CYP1A1-antibody-conjugate-treated cells than in control cells. However, FITC-insulin (lacking anti CYP1A1 conjugates) or insulin alone also decreased BaP metabolism by 50%. This insulin-induced inhibition of BaP metabolism was observed for cultures treated with a concentration range of FITC-insulin from 50-1000 nM. FITC-conjugated gamma-globulin showed no significant binding to HepG2 cells by fluorescence microscopy, however, FITC-insulin-antibody conjugates bound extensively, suggesting that FITC-insulin conjugates still retain the ability to bind insulin receptors. These results demonstrate that free insulin, FITC-insulin or FITC-insulin conjugated to antibodies are effective inhibitors of BaP metabolism in cells in culture.

Idiopathic subglottic stenosis

OBJECTIVE

To review our patients with subglottic stenosis and describe a rare subclass of patients in whom the cause of subglottic scarring and narrowing remains unknown.

DESIGN

A retrospective chart review and clinical update were performed on all patients seen with the diagnosis of subglottic stenosis.

SETTING

The patient pool represents a collection of primary care patients within a suburb of Boston, Mass, and tertiary referrals from community and out-of-state otolaryngologists.

PATIENTS

The charts of 80 patients were reviewed, and 10 of the 80 patients fulfilled the criteria for idiopathic subglottic stenosis.

INTERVENTION

Diagnostic and therapeutic intervention ranged from laboratory tests, topography, flexible bronchoscopy, rigid endoscopy and biopsy, laser-assisted dilation, and resection and repair of the lesion.

MAIN OUTCOME MEASURES

Attention was directed toward the character of the lesion, treatment modality, and clinical outcome.

RESULTS

From 1985 to 1992, 10 patients with idiopathic subglottic stenosis were treated at the Lahey Clinic, Burlington, Mass. Eight patients required therapy for exertional dyspnea. Endoscopic laser incision and dilation were performed in all eight patients, with good initial results. Four patients were treated successfully with endoscopy alone: three required only one dilation, and the fourth required a second dilation. The remaining four patients, who had longer and more complex stenoses, have had repeated restenosis at intervals ranging from 1.5 to 12 months. Two of these patients have undergone laryngotracheal resection and reconstruction and were without evidence of restenosis 10 and 20 months after surgery.

CONCLUSIONS

There exists a subclass of patients with subglottic stenosis of unknown cause. Symptomatic idiopathic subglottic stenosis may be treated successfully with laser incision and dilation if the stenosis is simple and short. More complex, longer stenoses are prone to recurrence and are more definitively managed by resection and reconstruction of the narrowed area.