Correction of genu recurvatum by the Ilizarov method

The Ilizarov apparatus was used to carry out opening-wedge callotasis of the proximal tibia in ten patients who had suffered premature asymmetrical closure of the proximal tibial physis and subsequent genu recurvatum. In four knees, the genu recurvatum was entirely due to osseous deformity, whereas in six it was associated with capsuloligamentous abnormality. Preoperatively, the angle of recurvatum averaged 19.6 degrees (15 to 26), the angle of tilt of the tibial plateau, 76.6 degrees (62 to 90), and the ipsilateral limb shortening, 2.7 cm (0.5 to 8.7). The average time for correction was 49 days (23 to 85). The average duration of external fixation was 150 days (88 to 210). Three patients suffered complications including patella infera, pin-track infection and transient peroneal nerve palsy. At a mean follow-up of 4.4 years, all patients, except one, had achieved an excellent or good radiological and functional outcome.

Cyclin D1 overexpression is an indicator of poor prognosis in resectable non-small cell lung cancer

Cyclin D1 is one of the G1 cyclins that control cell cycle progression by allowing G1 to S transition. Overexpression of cyclin D1 has been postulated to play an important role in the development of human cancers. We have investigated the correlation between cyclin D1 overexpression and known clinicopathological factors and also its prognostic implication on resected non-small-cell lung cancer (NSCLC) patients. Formalin-fixed and paraffin-embedded tumour tissues resected from 69 NSCLC patients between stages I and IIIa were immunohistochemically examined to detect altered cyclin D1 expression. Twenty-four cases (34.8%) revealed positive immunoreactivity for cyclin D1. Cyclin D1 overexpression is significantly higher in patients with lymph node metastasis (50.0% vs 14.4%, P = 0.002) and with advanced pathological stages (I, 10%; II, 53.8%; IIIa, 41.7%, P = 0.048; stage I vs II, IIIa, P = 0.006). Twenty-four patients with cyclin D1-positive immunoreactivity revealed a significantly shorter overall survival than the patients with negativity (24.0 +/- 3.9 months vs 50.1 +/- 6.4 months, P = 0.0299). Among 33 patients between stages I and II, nine patients with cyclin D1-positive immunoreactivity had a much shorter overall survival (29.7 +/- 6.1 months vs 74.6 +/- 8.6 months, P = 0.0066). These results suggest that cyclin D1 overexpression is involved in tumorigenesis of NSCLCs from early stage and could be a predictive molecular marker for poor prognosis in resectable NSCLC patients, which may help us to choose proper therapeutic modalities after resection of the tumor.

Intravitreal dexamethasone effect on intravitreal vancomycin elimination in endophthalmitis

OBJECTIVE

To determine whether intravitreal dexamethasone administration can alter the elimination of intravitreal vancomycin hydrochloride in rabbit eyes with experimental Streptococcus pneumoniae endophthalmitis.

METHODS

Albino rabbits were infected with an intravitreal inoculum of S pneumoniae (2 x 10(3) colony-forming units) and randomized after 24 hours to treatment with intravitreal vancomycin hydrochloride (1 mg), alone or in combination with intravitreal dexamethasone (400 microg). For comparison, uninfected eyes were similarly treated. All eyes were enucleated 24, 48, or 72 hours after treatment, and vitreous levels of vancomycin were quantitated using a fluorescence polarizing immunoassay.

RESULTS

The half-life of intravitreal vancomycin in infected eyes was prolonged from 48 to 84 hours when eyes were treated with dexamethasone. Conversely, such treatment shortened the half-life in uninfected eyes from 56 to 42 hours.

CONCLUSIONS

Intravitreal dexamethasone administration reduces the elimination of intravitreal vancomycin in rabbit eyes with pneumococcal endophthalmitis, whereas an opposite effect is noted in uninfected eyes.

CLINICAL RELEVANCE

In patients with eyes having endophthalmitis caused by virulent organisms, the elimination of intravitreal vancomycin may be reduced when intraocular inflammation is minimized with corticosteroid therapy. This may enhance the efficacy of intravitreal vancomycin therapy in treating the infection.

Powered instrumentation for rhinoplasty and septoplasty

Advances in surgical instrumentation are generally intended to allow the performance of a surgical maneuver more efficiently and accurately. Powered instrumentation may allow improved precision and ease in certain aspects of rhinoplasty and septoplasty. Through improved precision, tissue trauma can be minimized.

Protective effect of chlormethiazole, a sedative, against acetaminophen-induced liver injury in mice

OBJECTIVES

The hepatotoxicity of acetaminophen is not a result of the parent compound but is mediated by its reactive metabolite N-acetyl-p-benzoquinone imine. Cytochrome P4502E1 (CYP2E1) is the principal enzyme of this biotransformation, which accounts for approximately 52% of the bioactivation in human microsomes. Recently, chlormethiazole a sedative drug, is reported to be an efficient inhibitor of CYP2E1 activity in human beings. In this study we wished to evaluate whether chlormethiazole, an inhibitor of CYP2E1, could prevent acetaminophen-induced liver injury in mice.

METHODS

Acetaminophen, at doses ranging from 200 to 600 mg/kg, was injected into the peritoneum of female C57BL/6 inbred mice fasted for four hours. Chlormethiazole (60 mg/kg) or 5% dextrose water was given 30 min before or 2 h after acetaminophen. Serum aminotransferase activities, histologic index score, survival rate and hepatic malondialdehyde levels were compared.

RESULTS

Pretreatment with chlormethiazole 30 min before 400 mg/kg of acetaminophen completely inhibited acetaminophen-induced liver injury (median 118.5 U/L, range 75 to 142 vs. 14,070 U/L, range 5980 to 27,680 for AST; 49 U/L, range 41 to 64 vs. 15,330 U/L, range 13,920 to 15,940 for ALT). In mice receiving chlormethiazole 2 h after acetaminophen, the mean AST and ALT levels were also less elevated, reaching only 20% of the value of acetaminophen-only group. These protective effects were confirmed histologically. Whereas more than 50% of mice died at 500 mg/kg of acetaminophen, all the mice pretreated with chlormethiazole survived at the same dose.

CONCLUSION

Chlormethiazole effectively reduces acetaminophen-induced liver injury in mice. Further studies are needed to assess its role in humans.

A 3-year multi-institutional experience with the liposhaver

OBJECTIVE

To report a 3-year multi-institutional clinical experience with the liposhaver in facial plastic surgery.

DESIGN

Nonrandomized, nonblinded, multi-institutional evaluation of the liposhaver in a clinical setting.

INTERVENTIONS

Seventy-two patients who presented for facial plastic surgical procedures underwent surgery with the liposhaver. Seventy-six liposhaving procedures and 74 concomitant procedures were performed. Standardized preoperative and postoperative photographs were obtained.

OUTCOME MEASURE

Subjective evaluation by the surgeons who performed the procedures.

RESULTS

The liposhaver was used successfully in all cases. The fat was cleanly shaved and the contour results were even, without dimpling or significant asymmetry. Operative time was comparable to that of conventional liposuction. There were no cases of facial nerve injury and no evidence of increased bleeding intraoperatively. Two male patients had small postoperative hematomas in the immediate postoperative period that were successfully treated with conservative measures. An additional patient developed a small hematoma on postoperative day 5 that was effectively treated with needle aspiration and a pressure dressing.

CONCLUSION

This 3-year multi-institutional report suggests that the liposhaver continues to offer a precise alternative to conventional liposuction.

Combined effects of ethanol and garlic on hepatic ethanol metabolism in mice

The combined effects of ethanol and components in fresh garlic on ethanol metabolism were investigated in the livers of mice. Male, 11-wk-old C3H/HeNCrj mice were intragastrically administered 2 g ethanol/kg body weight after being administered fresh garlic juice for 8 d (garlic group), and changes in the concentrations of ethanol, acetaldehyde and acetate in the serum, and changes in the activity of hepatic enzymes related to ethanol metabolism in mice were examined. The increases in the concentrations of acetaldehyde and acetate in the serum after ethanol administration tended to be diminished following garlic administration. The microsomal ethanol-oxidizing system (MEOS) in the livers of the garlic groups was significantly lower than that of the control microsomes at 2 h after ethanol administration. It therefore seems that the decrease of MEOS in hepatic microsomes caused a smaller increase in the acetaldehyde concentration in the serum of the garlic groups because cytosolic alcohol dehydrogenase showed no significant difference between the control and garlic groups. After ethanol administration, the content of cytochrome P-450 in the hepatic microsomes of the control groups increased, while that of the garlic groups did not change although cytochrome P-450 (CYP) 2E1 and 1A2 in the hepatic microsomes of the garlic groups increased. These results indicate that the induction of isozymes of cytochrome P-450 other than CYP 2E1 and 1A2 was inhibited following garlic administration. Cytosolic high Km and total aldehyde dehydrogenase (AIDH) in the liver of the garlic groups tended to be lower than those activities of the control groups at 1 and 2 h after ethanol administration. It therefore seems that the decreases of AIDH in the hepatic cytosols diminished the increase of acetate in the serum of the garlic groups after ethanol administration. These results suggest that the ethanol metabolism in the mouse liver is controlled by components in fresh garlic juice.

Expression of differentiation markers during fetal skin development in humans: immunohistochemical studies on the precursor proteins forming the cornified cell envelope

The cornified cell envelope is formed during the terminal differentiation of epidermis through cross-linking of specific proteins by transglutaminases. The specific arrangement of individual protein in the cornified cell envelope and participation of individual protein in the cornified cell envelope at different regions of skin, i.e., palm, foreskin, lips, etc. are not clearly understood. In order to understand the pattern and expression schedule of each individual precursor protein during the differentiation and formation of cornified cell envelope, the expression of precursor proteins in developing human fetal skins from the first to the third trimester were examined by immunohistochemical studies. Involucrin was found in the periderm and intermediate layer from 14 wk estimated gestational age, while loricrin and small proline-rich protein 1 were found in the periderm from 16 wk estimated gestational age. Filaggrin and trichohyalin that are absent in the adult cornified cell envelope were found in the granular and horny layers from 24 wk estimated gestational age. The precursor proteins except trichohyalin did not change their patterns after the onset of initial expression during development. Trichohyalin was transiently expressed in the granular and horny layers of the epidermis from 24 wk estimated gestational age with peak expression at 27 wk estimated gestational age, but was not detected in adult skin. In hair follicles, trichohyalin expression was stable without change from 20 wk estimated gestational age. These findings suggest that fetal skin may have different sets of barriers from the second trimester; the immature cornified cell envelope is formed in the early second trimester and the mature cornified cell envelope is formed in the late second or early third trimester when filaggrin and trichohyalin appear.

Vesicular ATPase-overexpressing cells determine the distribution of malaria parasite oocysts on the midguts of mosquitoes

In Plasmodium-infected mosquitoes, oocysts are preferentially located at the posterior half of the posterior midgut. Because mosquitoes rest vertically after feeding, the effect of gravity on the ingested blood has been proposed as the cause of such a biased distribution. In this paper, we examined the oocyst distribution on the midguts of mosquitoes that were continuously rotated to nullify the effect of gravity and found that the typical pattern of oocyst distribution did not change. Invasion of the midgut epithelium by ookinetes was similarly found to be biased toward the posterior part of the posterior midgut. We examined whether the distribution of oocysts depends on the distribution of vesicular ATPase (V-ATPase)-overexpressing cells that Plasmodium ookinetes preferentially use to cross the midgut epithelium. An antiserum raised against recombinant Aedes aegypti V-ATPase B subunit indicated that the majority of V-ATPase-overexpressing cells in Ae. aegypti and Anopheles gambiae are localized at the posterior part of the posterior midgut. We propose that the typical distribution of oocysts on the mosquito midgut is attributable to the presence and the spatial distribution of the V-ATPase-overexpressing cells in the midgut epithelium.

Differential expression of mouse Disabled 2 gene in retinoic acid-treated F9 embryonal carcinoma cells and early mouse embryos

Using a differential display PCR, we identified a differentially expressed cDNA fragment which was detectable in retinoic acid (RA) treated F9 embryonal carcinoma (EC) cells but not in untreated F9 cells. A homology search of the Gene Bank indicated that the cDNA fragment is part of the mouse homolog of the Drosophila Disabled (mDab2) gene. Aggregate cultures of F9 EC cells grown in the presence of the RA differentiated into nonmalignant cells resembling the visceral endoderm of the mouse embryo. Upon induction of endodermal differentiation with 10(-7) M RA, the gene expression of mDab2 was increased gradually during the first 96 h. Neither undifferentiated F9 cells, nor the undifferentiated aggregate cells without RA expressed mDab2. Whole-mount in situ hybridization and quantitative RT-PCR also showed that the temporal expression pattern of the mDab2 gene coincides with the initiation pattern of RA synthesis that occurs during mouse embryogenesis. Also, two alternative splicing messages of mDab2 were detected in a tissue specific manner. All the data indicate that mDab2 may play an important role in RA-induced signal transduction during mouse development.

Clinical application of the M-numbers of aortic cannulas during hypothermic cardiopulmonary bypass in pediatric patients

A standardized system to describe the pressure-flow characteristics of a given cannula has recently been proposed and has been termed the M-number system. Using 3 different sizes of aortic cannulas in 50 pediatric cardiac patients on hypothermic cardiopulmonary bypass, we analyzed the correlation between experimentally and clinically derived M-numbers and found it to be positive. Clinical M-numbers were typically 0.35 to 0.55 greater than experimental M-numbers and correlated inversely with a patient's temperature change; this was most probably due to increased blood viscosity arising from hypothermia. This inverse relationship was more marked in higher M-number cannulas. The clinical data obtained in this study suggest that the experimentally derived M-number correlates strongly with the clinical performance of the cannula and that the influence of temperature is significant.

Surgery for the dysfunctional nasal valve. Cadaveric analysis and clinical outcomes

OBJECTIVES

To quantify changes in the cross-sectional area of the nasal valve after placement of spreader grafts and flaring sutures and to review clinical outcomes after nasal valve surgery.

DESIGN

The minimal cross-sectional area of cadaveric nasal valves was measured after placement of spreader grafts and flaring sutures. Clinical outcomes for patients undergoing functional rhinoplasty were retrospectively reviewed.

SETTING

Academic medical center.

SUBJECTS

Six fresh cadaver heads and a review of patients from September 1994 through May 1998.

INTERVENTION

Acoustic rhinometry was performed after placement of spreader grafts, flaring sutures, and the two together. Clinically, a site-specific repair was performed with spreader grafts and flaring sutures for statically narrowed internal nasal valves and cartilaginous battens for dynamic collapse.

MAIN OUTCOME MEASURE

Cross-sectional areas of cadaveric valves. Functional and aesthetic results were determined by nasal patency scores from 1 (complete obstruction) to 10 (complete patency) and a rating of postsurgical cosmetic changes.

RESULTS

Spreader grafts improved the cadaveric minimal cross-sectional areas by 5.4% (P > .05), flaring sutures by 9.1% (P > .05), and spreader grafts combined with flaring sutures by 18.7% (P < .05). Mean nasal patency scores improved from 3.4 to 6.5 (P < .01) with the combination of spreader grafts and flaring sutures. Cartilaginous battens improved scores from 2.7 to 6.3 (P < .01).

CONCLUSIONS

The combination of flaring sutures and spreader grafts has the greatest impact on the cadaveric nasal airway. Either technique alone failed to have a statistically significant impact on the minimal cross-sectional area of the nasal valve. Clinical review confirms significant improvement in nasal function using this combination technique.

Functional nasal surgery

Functional nasal surgery is designed to repair nasal obstruction frequently caused by previous reduction rhinoplasty or blunt nasal trauma. Distinguishing the statically narrowed nasal valve from the weak sidewall with dynamic collapse is an important part of the preoperative evaluation. Our workhorse for repair of static obstruction is the combination of spreader grafts and flaring sutures, which together create a significant increase in the intranasal valve area. Dynamic collapse of the sidewall is corrected with cartilaginous batten grafts designed to increase sidewall rigidity. Less common causes of valve obstruction, such as tip ptosis, facial paralysis, cicatricial stenosis, Mohs reconstruction, and paradoxical lateral crura, are repaired by more individualized techniques.

A novel Bacillus subtilis gene, antE, temporally regulated and convergent to and overlapping dnaE

A Bacillus subtilis promoter, Px, that functions in a convergent manner with the sigA operon promoter P3 has been found in the sigA operon. Promoter Px is turned on at the same time as promoter P3 during early sporulation. The transcript from promoter Px codes for a small protein with partial homology to the OmpR protein from Escherichia coli and also carries an untranslated sequence at its 3' end that is complementary to the 5' end of the P3 transcript, which codes for the ribosome binding site of dnaE. The gene controlled by Px has been called antE. The expression of antE does not require sigmaB, sigmaE, or sigmaH. Px was transcribed in vitro by the sigmaA holoenzyme and is the seventh promoter to be recognized in the sigmaA operon. A possible role for the antE gene during early sporulation is proposed.

Isolation and characterization of immune-related genes from the fall webworm, Hyphantria cunea, using PCR-based differential display and subtractive cloning

Following injection of bacteria into the hemocoel of the fall webworm, Hyphantria cunea, several inducible genes were identified and characterized using PCR-based differential display (DD-PCR) and subtractive cloning. Ten immune-related cDNA clones (Hdd1, Hdd2, Hdd3, Hdd11, Hdd13, Hdd15, Hdd17, Hdd23, Hs106, Hs302) were isolated and characterized. The deduced amino acid sequence of Hdd2 was shown to be a member of the copper, zinc superoxide dismutase (Cu-Zn SOD) family. The H. cunea Cu-Zn SOD is novel in that it is up-regulated following a bacterial challenge and has a putative signal peptide suggesting its secretion and involvement in the insect immune response. Hdd3 was found to encode a new member of the serpin (serine protease inhibitor) family. The putative lectin corresponding to Hdd15 is of a different kind in that it has two lectin C domains in a single molecule. These two lectin C domains show significant homology to the lectin C domain of Periplaneta lipopolysaccharide binding protein (LPS-BP). Three cloned genes, Hdd17, Hs106 and Hs302, encode a homologue to Bombyx mori Gram negative binding protein, a hemolin-like protein and a attacin-like protein, respectively. The deduced amino acid sequences from Hdd11 showed weak homology with a Locusta migratoria hemolymph protein. On the contrary, Hdd1, Hdd13 and Hdd23 did not reveal any significant homology with known proteins. All of the 10 genes were clearly inducible by E. coli and M. luteus injection. Injection of distilled water only slightly induced mRNA levels. Comparison of temporal mRNA expression following E. coli injection showed three types of expression patterns.

Prevalence of specific antibodies to Chlamydia pneumoniae in Korea

To clarify the endemic status of Chlamydia pneumoniae in Korea, the incidence of antibodies in 564 serum samples from healthy individuals, patients with respiratory infection, and cord blood specimens was evaluated. We conclude that C. pneumoniae infection is highly endemic in Korea and that this infection is associated with acute respiratory diseases.

Two-step autocatalytic processing of the glutaryl 7-aminocephalosporanic acid acylase from Pseudomonas sp. strain GK16

The glutaryl-7-aminocephalosporanic acid (GL-7-ACA) acylase of Pseudomonas sp. strain GK16 is an (alphabeta)2 heterotetramer of two nonidentical subunits. These subunits are derived from nascent polypeptides that are cleaved proteolytically between Gly198 and Ser199 after the nascent polypeptides have been translocated into the periplasm. The activation mechanism of the GL-7-ACA acylase has been analyzed by both in vivo and in vitro expression studies, site-directed mutagenesis, in vitro renaturation of inactive enzyme precursors, and enzyme reconstitution. An active enzyme complex was found in the cytoplasm when its translocation into the periplasm was suppressed. In addition, the in vitro-expressed GL-7-ACA acylase was processed into alpha and beta subunits, and the inactive enzyme aggregate of the precursor was also processed and became active during the renaturation step. Mutation of Ser199 to Cys199 and enzyme reconstitution allowed us to identify the secondary processing site that resides in the alpha subunit and to show that Ser199 of the beta subunit is essential for these two sequential processing steps. Mass spectrometry clearly indicated that the secondary processing occurs at Gly189-Asp190. All of the data suggest that the enzyme is activated through a two-step autocatalytic process upon folding: the first step is an intramolecular cleavage of the precursor between Gly198 and Ser199 for generation of the alpha subunit, containing the spacer peptide, and the beta subunit; the second is an intermolecular event, which is catalyzed by the N-terminal Ser (Ser199) of the beta subunit and results in a further cleavage and the removal of the spacer peptide (Asp190 to Gly198).

Hyperbaric oxygen for the management of radionecrosis of bone and cartilage

OBJECTIVES

To review the use of hyperbaric oxygen in the management of radionecrosis of the head and neck.

STUDY DESIGN

A retrospective analysis of patients utilizing chart review and telephone interviews. All patients diagnosed with osteoradionecrosis and chondroradionecrosis of the head and neck and treated with hyperbaric oxygen at the University of Virginia are included.

METHODS

Demographics, pretreatment data, and precipitating events were recorded. Outcomes were evaluated using a grading scale of symptomatology and physical examination as determined by the patient and physician.

RESULTS

Sixteen patients with osteoradionecrosis and five with chondroradionecrosis were reviewed. All patients showed clinical improvement with decreased pain following HBO therapy. None of the patients with chondroradionecrosis required laryngectomies, and two of the four who were tracheotomy dependent were successfully decannulated. The patient and physician grading scores demonstrated moderate to significant improvement in both groups following therapy.

CONCLUSION

The successful use of hyperbaric oxygen for the management of radionecrosis of the head and neck is supported. The unusual prevalence of chondroradionecrosis may be an early reflection of changes in treatment protocols for patients with head and neck cancer.

Effects of motorcycle exhaust on cytochrome P-450-dependent monooxygenases and glutathione S-transferase in rat tissues

The effects of motorcycle exhaust (ME) on cytochrome P-450 (P-450)-dependent monooxygenases were determined using rats exposed to the exhaust by either inhalation, intratracheal, or intraperitoneal administration. A 4-wk ME inhalation significantly increased benzo[a]pyrene hydroxylation, 7-ethoxyresorufin O-deethylation, and NADPH-cytochrome c reductase activities in liver, kidney, and lung microsomes. Intratracheal instillation of organic extracts of ME particulate (MEP) caused a dose- and time-dependent significant increase of monooxygenase activity. Intratracheal treatment with 0.1 g MEP extract/kg markedly elevated benzo[a]pyrene hydroxylation and 7-ethoxyresorufin O-deethylation activities in the rat tissues 24 h following treatment. Intraperitoneal treatment with 0.5 g MEP extract/kg/d for 4 d resulted in significant increases of P-450 and cytochrome b5 contents and NADPH-cytochrome c reductase activity in liver microsomes. The intraperitoneal treatment also markedly increased monooxygenases activities toward methoxyresorufin, aniline, benzphetamine, and erythromycin in liver and benzo[a]pyrene and 7-ethoxyresorufin in liver, kidney, and lung. Immunoblotting analyses of microsomal proteins using a mouse monoclonal antibody (Mab) 1-12-3 against rat P-450 1A1 revealed that ME inhalation, MEP intratracheal, or MEP intraperitoneal treatment increased a P-450 1A protein in the hepatic and extrahepatic tissues. Protein blots analyzed using antibodies to P-450 enzymes showed that MEP intraperitoneal treatment caused increases of P-450 2B, 2E, and 3A subfamily proteins in the liver. The ME inhalation, MEP intratracheal, or MEP intraperitoneal treatment resulted in significant increases in glutathione S-transferase activity in liver cytosols. The present study shows that ME and MEP extract contain substances that can induce multiple forms of P-450 and glutathione S-transferase activity in the rat.

A second form of phenylalanine ammonia-lyase from leaf mustard

Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) catalyzes the elimination of ammonium ion from L-phenylalanine in a variety of plants and fungal species. PAL was previously purified and characterized from leaf mustard in our laboratory. In the present study, we purified a second phenylalanine ammonia-lyase (PAL II) from leaf mustard by a combination of ion exchange chromatography and gel filtration. PAL I and PAL II migrate at a different rate on native polyacrylamide gel electrophoresis. It consists of four subunits, each having the molecular mass of about 37,000 Da. Its isoelectric point and Km value for L-phenylalanine were found to be 5.4 and 3.8 x 10(-5)M, respectively. The purified enzyme has an optimum pH and temperature of 8 and 45 degree C, respectively. It is activated about 2-fold by caffeic acid (1 mM), whereas it is inhibited to 15% by Zn2+ (1 mM). However, the physiological role of PAL II remains unknown.

Gene frequencies of eight human platelet-specific antigens in Koreans

Human platelet-specific antigens (HPAs) are found on platelet membrane glycoproteins and are the target of platelet alloantibodies that mediate platelet destruction in neonatal alloimmune thrombocytopenia (NAIT), post-transfusion purpura (PTP) and refractoriness to platelet transfusion therapy. The biallelic polymorphism of all HPA systems is known to be due to a substitution of a single base pair. This study was performed to investigate the frequency of the HPA genes in Koreans, based on these substitutions. The genotypes of eight HPA systems were determined by polymerase chain reaction using sequence-specific primers (PCR-SSP) for HPA-1, -2, -4, -5, and -8 and restriction fragment length polymorphism (RFLP) for HPA-3, -6, and -7. The gene frequencies obtained from 200 unrelated Koreans were 0.99 and 0.01 for HPA-1a and -1b, 0.92 and 0.08 for HPA-2a and -2b, 0.55 and 0.45 for HPA-3a and -3b, 0.99 and 0.01 for HPA-4a and -4b, 0.98 and 0.02 for HPA-5a and -5b, and 0.98 and 0.02 for HPA-6a and -6b. All the individuals tested were homozygotes for HPA-7a and HPA-8a. It has been reported that the HPA-1b antigen is extremely rare (less than 0.3%) in Oriental populations, but this study suggests that the frequency of this antigen in Koreans (2.0%) is higher than in Japanese and Chinese populations.

Autogenous tissue-engineered cartilage: evaluation as an implant material

OBJECTIVES

To determine whether autogenous tissue-engineered cartilage grafts can be synthesized in predetermined shapes, to compare tissue-engineered cartilage with native cartilage with respect to histological characteristics and biomechanical properties, and to demonstrate how multiple transplantations affect tissue-engineered cartilage.

DESIGN

Controlled, prospective animal study.

SUBJECTS

Twenty New Zealand white rabbits, 3 weeks old.

INTERVENTIONS

Autogenous chondrocytes were seeded onto biodegradable polyglycolic acid-poly-L-lactic acid copolymer templates in 1 of 3 shapes (cross, nasal tip graft, or auricle). Grafts and controls of sculpted cartilage were divided among 3 groups: short-term implantation (4 or 8 weeks), long-term implantation (6 or 12 months), and a reimplantation group. The gross morphological features, histological findings, and tensile strength of grafts were assessed.

RESULTS

Production of tissue-engineered cartilage was confirmed in 30 of 31 implants. Histological evaluation demonstrated characteristic cartilaginous matrix, but with prominent vascular and fibrous tissue ingrowth. In long-term implantation grafts (n=4), foci of osteoid were evident by 6 months. In the subset of transplanted grafts (n=7), 5 of 7 demonstrated significant loss of cartilage viability. Tensile strength measurements demonstrated values 24% and 41% of those of controls at 4 and 8 weeks, respectively.

CONCLUSIONS

Tissue-engineered autogenous cartilage can be reliably produced, and predetermination of graft shape is possible. Histologically, grafts represent composites of mature cartilage infiltrated by vasculature and fibrous tissue, with delayed osteoid formation. Graft viability is compromised by early transplantation, and tensile strength is less than that of native cartilage. These results demonstrate the feasibility of tissue-engineered cartilage as a future graft material.

Immunohistochemical localization of ganciclovir in the human retina

PURPOSE

To localize ganciclovir in the retina of human eyes treated with intravenous or intravitreal ganciclovir for cytomegalovirus (CMV) retinitis.

METHODS

Paraffin-embedded five-micron sections of autopsy eyes were obtained from seven patients as follows: two patients with CMV retinitis treated with intravenous ganciclovir; two patients with CMV retinitis treated with an intravitreal sustained-release ganciclovir device; one patient with CMV retinitis treated with intravenous foscarnet; and two patients with AIDS without CMV retinitis who did not receive any anti-CMV therapy. The paraffin was removed from the sections, and indirect immunofluorescent staining was performed, using an antiserum to ganciclovir.

RESULTS

Bright fluorescent staining was noted in the retinal pigment epithelium (RPE) and photoreceptor outer segments of eyes treated with intravenous or intravitreal ganciclovir, but not in eyes treated with foscarnet or without CMV retinitis. In addition, patches of bright fluorescent staining of the internal limiting membrane was noted in eyes treated with intravitreal ganciclovir.

CONCLUSIONS

Ganciclovir is detected in the outer retina of patients with CMV retinitis treated with intravenous or intravitreal therapy. The drug is detected also in the internal limiting membrane in eyes treated with the intravitreal sustained-release ganciclovir device.

Dopamine transporter density measured by [123I]beta-CIT single-photon emission computed tomography is normal in dopa-responsive dystonia

The clinical distinction between dopa-responsive dystonia (DRD) and juvenile Parkinson's disease JPD) can pose a diagnostic challenge. Both conditions are dopa responsive. However, long-term L-dopa benefit is very different between the two. The difference in the prognosis is due to presence or absence of nigral cell loss. In JPD, there is degenerative nigral cell loss, whereas there are enzymatic defects in dopamine synthesis without cell loss in DRD. Mutations have been found in the GTP cyclohydrolase I (GCH-I) and tyrosine hydroxylase genes in DRD. As the discovered mutations are multiple and more are expected to be found, it is difficult to confirm or exclude DRD by mutation studies. Measurement of cerebrospinal fluid (CSF) neopterin will detect DRD from mutations in the GCH-I gene but not from mutations in tyrosine hydroxylase. The dopamine transporter (DAT) is a protein in the dopaminergic nerve terminals. (1R)-2beta-Carbomethoxy-3beta-(4-[123I]iodophenyl)tropane ([123I]beta-CIT) is a ligand for the DAT, and it was shown to be a useful nuclear imaging marker for neurons that degenerate in Parkinson's disease (PD). As DRD was shown to have a normal DAT without nigral cell loss in a postmortem study, we predicted that the DAT measured in vivo by nuclear imaging will be normal in DRD and will differentiate DRD from JPD. Therefore, we performed [123I]beta-CIT single-photon emission computed tomography ([123I]beta-CIT SPECT) in clinically diagnosed DRD, PD, and JPD, and examined whether DAT imaging can differentiate DRD from PD and JPD. We then examined whether DAT imaging can provide a screening tool for molecular genetic studies, by studying mutations in the candidate gene GCH-I and measuring CSF neopterin. Five females (4 from two families, and 1 sporadic) were diagnosed as DRD based on early-onset foot dystonia and progressive parkinsonism beginning at ages 7 to 12. All patients were functioning normally on L-dopa 100 to 250 mg/day for up to 8 years. SPECT imaging was obtained after intravenous injection of [123I]beta-CIT; 15 healthy volunteers served as normal control, and 6 PD and 1 JPD as disease controls. [123I]beta-CIT striatal binding was normal in DRD, whereas it was markedly decreased in PD and JPD. Gene analysis showed a novel nonsense mutation in the GCH-I gene in one family. No mutation was found in the other family or in the sporadic case. CSF neopterin was markedly decreased in the 4 tested patients. [123I]beta-CIT SPECT is a sensitive method for probing the integrity of nigrostriatal dopaminergic nerve terminals. A normal striatal DAT in a parkinsonian patient is evidence for a nondegenerative cause of parkinsonism and differentiates DRD from JPD. Finding a new mutation in one family and failure to demonstrate mutations in the putative gene in other cases supports the usefulness of DAT imaging in diagnosing DRD.

A simulation of subtractive hybridization

Various strategies employed in genomic DNA cloning by subtractive hybridization have been examined by computer simulations, with the comparison between the predictions and the published results. The result shows that the efficiency of target sequence enrichment and the sensitivity to experimental conditions depend strongly on the enrichment strategy employed. The strategy selecting only tester/tester after hybridization can be very efficient to enrich targets. For successful target enrichment, however, the strategy requires a highly efficient subtraction method and proper hybridization conditions. The strategy also requires that the selected DNA be amplified by polymerase chain reaction (PCR) after each or each alternate subtraction. By contrast, the strategy selecting tester/tester plus single-stranded tester is less sensitive to various experimental factors, compared with the strategy selecting only tester/tester. However, it is not as efficient. With this strategy, the tester DNA selected may or may not be amplified by PCR before the next round. In the case of the strategy selecting single-stranded tester, the target DNA can be successfully enriched only when the selected DNA is directly used without PCR amplification in the next round. The strong features of existing methods can be combined to develop a protocol that is more efficient and more reliable.

Measurement of cell proliferation by labeling of DNA with stable isotope-labeled glucose: studies in vitro, in animals, and in humans

A method for measuring DNA synthesis and, thus, cell proliferation, in vivo is presented. The technique consists of administering [6,6-2H2]Glc or [U-13C]Glc, isolating genomic DNA, hydrolyzing enzymatically to free deoxyribonucleosides, and derivatizing for GC-MS analysis of dA or dG isotopic enrichments, or both. Comparison of dA or dG to extracellular Glc enrichment (with a correction for intracellular dilution) reveals the fraction of newly synthesized DNA, by application of the precursor-product relationship. Thus, the technique differs from the widely used [3H]thymidine or BrdUrd techniques in that the de novo nucleotide synthesis pathway, rather than the nucleoside salvage pathway, is used to label DNA; the deoxyribose rather than the base moiety is labeled; purine rather than pyrimidine deoxyribonucleosides are analyzed; and stable isotopes rather than radioisotopes are used. The method is applied here in vitro to the growth of HepG2 and H9 cells in culture; in animals to proliferation of intestinal epithelium, thymus, and liver; and in humans to granulocyte turnover in blood. In all instances, measured cell proliferation kinetics were consistent with expected or independently measured kinetics. The method has several advantages over previously available techniques for measuring cell turnover, involves no radioactivity or potentially toxic metabolites, and is suitable for use in humans. The availability of a reliable and safe method for measuring cell proliferation in humans opens up a number of fundamental questions to direct experimental testing, including basic problems related to cancer, AIDS, and other pathologic states.

Identification of functionally important residues of human thrombopoietin

Thrombopoietin (TPO) is a megakaryocyte growth and differentiation factor. It consists of a characteristic two domain structure. The amino-terminal domain of TPO has a sequence homology with erythropoietin and is required for the binding and activation of its receptor c-Mpl. To determine the functionally important regions interacting with its receptor, a series of site-directed mutants of TPO were constructed based on a three-dimensional model of the amino-terminal domain. Two strategies of mutagenesis were employed: 1) nonnative N-linked glycosylation scan of 12 residues predicted to be on the surface, and 2) alanine replacement scan of mostly charged 44 amino acid residues. Each TPO mutein was transiently expressed in COS7 cells, and the specific bioactivity of the TPO protein secreted into the culture medium was measured using a recombinant BaF3 cell line expressing human c-Mpl. Four alanine substitutions at Arg10, Pro42, Glu50, and Lys138 nearly or completely abolished the activity, whereas the mutation at Arg14 slightly decreased the activity, suggesting that these residues are functionally important in interacting with its receptor. These residues mapped to helix A, loop AB, and helix D. Sequence comparison between human TPO and other mammalian TPO showed that the identified residues are completely conserved among the species. However, unlike the recent report on the mutational analysis of TPO, alanine substitutions at Lys52, Lys59, Arg136, and Arg140 did not affect the TPO activity significantly in our system. The identified receptor binding regions of TPO are analogous to those of human growth hormone and erythropoietin. Based on the similarity of these three cytokines, we propose that Lys138 of helix D and Pro42 and Glu50 of loop AB may constitute one binding region, whereas Arg10 and Lys14 of helix A may constitute the other binding region to dimerize the receptors.

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.