Verification of a hyperthermia model method using MR thermometry

Simulation of hyperthermia induced power and temperature distributions is becoming generally accepted and finding its way into clinical hyperthermia treatments. Such simulations provide a means for understanding the complete three-dimensional temperature distribution. However, the results of the simulation studies should be regarded with caution since modelling errors will result in differences between the actual and simulated temperature distribution. This study uses a diffusion weighted magnetic resonance (MR) based technique to measure hyperthermia induced temperature distributions in a three-dimensional space in a non-perfused phantom. The measured data are used to verify the accuracy of numerical simulations of the same three-dimensional temperature distributions. The simulation algorithm is a finite element based method that first computes the electromagnetic induced power deposition then the temperature distribution. Two non-perfused phantom studies were performed and qualitatively the MR and simulated distributions agreed for steady-state. However, due to the long MR sampling time (approximately 4 min), poor agreement between the simulations and MR measurements were obtained for thermal transients. Good agreement between the simulations and fibreoptic thermometry measurements were obtained. The fiberoptic measurements differed from the simulations by 0.11 +/- 0.59 degrees C and -0.17 +/- 0.29 degrees C (mean +/- standard deviation for the two studies).

Epidemiology of cleft lip and cleft palate in Mississippi

We present an epidemiologic study of the cases of cleft lip and cleft palate in Mississippi from 1980 through 1989. Cases were stratified by race (white and nonwhite) but not by association with a major malformation. During this period, a total of 457 new patients with cleft lip or cleft palate were identified from a population of approximately 439,354 live births. The incidence of total clefts in live-born infants was 1.36/1,000 for whites and 0.54/1,000 for nonwhites. White boys had a higher incidence of cleft lip and palate than white girls; black boys had an extremely low incidence of cleft lip, whereas black girls showed a higher incidence of cleft palate alone. Examination of the rate of cleft malformations for each county in Mississippi revealed no clearly defined pattern, nor were we able to demonstrate that rates were increased in a major agricultural area of the state, in which use of potentially toxic products is high.

Evaluation of poly(isobutylcyanoacrylate) nanoparticles for mucoadhesive ocular drug delivery. I. Effect of formulation variables on physicochemical characteristics of nanoparticles

A factorial design was applied to evaluate the effect of formulation variables on physicochemical properties of poly(isobutylcyanoacrylate) nanoparticles. Formulation variables were dextran T40 or T70 and Pluronic F68 or Tween 20 acting as stabilizer and surfactant respectively, and three pH levels (2, 4 and 7). Nanoparticles possessed unimodal particle size distribution with significant effect of dextran, surfactant and pH. A wide range of molecular weight distribution was observed with significant effect of pH and dextran on average molecular weight. NMR studies revealed the presence of dextran, monomer and surfactants in the nanoparticles. Solid state surface analysis using X-ray photoelectron spectroscopy confirmed the presence of three chemical environments to the carbon envelope, O-C = O, C-O/C identical to N and C-C.

Mainstream and sidestream cigarette smoke exposure increases retinol in guinea pig lungs

We have studied in guinea pigs the effects of cigarette smoke exposure on vitamin A (retinol) levels in plasma, lung, lung lavage, and liver. Smoke was generated from 1R3F cigarettes in a smoke exposure instrument designed by University of Kentucky Tobacco and Health Research Institute. Three-week-old male guinea pigs were exposed to mainstream, sidestream, or sham smoke, generated twice daily from three cigarettes for 6 weeks. In addition, some animals were kept as room controls for some time. After 6 weeks of smoke exposure, some animals were allowed to recover for 6 weeks without smoke. After 6 weeks of smoking, the plasma retinol levels were lower in both smoke exposed groups when compared to the values in the sham group. Furthermore, in comparison to the sham group, the mainstream and sidestream smoke exposed groups showed a 7.6- and 8.3-fold increase in the levels of lung retinol, respectively. After the 6-week recovery period, plasma retinol of both smoke-exposed groups reached the control levels. In contrast, withdrawal of smoking did not show such an effect on the lung retinol level in both mainstream or sidestream groups. Electronmicroscopy of the lungs showed deleterious alterations in the morphology of the lungs in both mainstream and sidestream groups. Although the mechanism(s) involved in the elevation of retinol content of the lung due to smoke exposure remains to be elucidated, it is of interest that elevation of retinol content and alteration of lung morphology occurred not only in the mainstream smoke exposed but also in the sidestream group.

Neurosurgical considerations on the anatomy of the medial canthus in children

Craniofacial surgery and anterior skull base surgical techniques require an intimate knowledge of periorbital structures. The medial orbital anatomy is especially important for midline approaches to nasion encephalocele, midline trauma, surgery for hypertelorism as well as midline approaches to anterior skull base lesions. The medial canthal tendon is of primary importance in anchoring the eyelid medially in a cosmetic and functional fashion. This review will summarize the anatomic features of the medial canthus and its surrounding structures, including vascular and muscular components. The intimate relationship of the three components of the medial canthal tendon to the nasal lacrimal apparatus is emphasized. Techniques to prevent injury as well as to repair abnormalities in this area will be discussed.

A dose ranging study to evaluate dermatan sulphate in preventing deep vein thrombosis following total hip arthroplasty

Dermatan sulphate catalyses thrombin inhibition by heparin cofactor II; it has a lower haemorrhagic to antithrombotic ratio than that of heparin in animal models. Consecutive patients aged forty years or more, electively undergoing total hip replacement under general anaesthesia, were randomly allocated to one of three dosage regimens of dermatan sulphate (MF701, Mediolanum Farmaceutici) given intramuscularly. These were 200 mg once daily (n = 50), 200 mg twice daily (n = 52) and 300 mg twice daily (n = 51), administered from twenty-four hours pre-operatively until the tenth postoperative day. The overall incidence of DVT assessed by bilateral venography was 53%, 51% and 34% respectively (Chi-square test for trend p = 0.06). The incidence of major proximal DVT was 10.6%, 8.5% and 2.1% respectively. Pulmonary embolism (PE) and bleeding were assessed in all 153 patients. There was one case of PE in each dose group. The incidence of bleeding episodes, volume of blood lost and blood transfusion requirements were low and showed no increase with increasing dose. The patients were followed up 4-8 weeks after discharge. We conclude that the two lower doses were subtherapeutic in this population, however dermatan sulphate given 300 mg twice daily, proved to be efficacious with an incidence of proximal major DVT of 2.1% and a low incidence of bleeding complications. A trial of dermatan sulphate 300 mg twice daily compared to standard prophylactic agents is needed.

Beta-adrenoreceptors of multiple affinities in a clonal capillary endothelial cell line and its functional implication

beta-Adrenoreceptor has been studied in a clonal capillary endothelial cell line established from the vascular bed of the bovine adrenal medulla. [3H]Dihydroalprenolol ([3H]DHA) binding to the isolated plasma membranes from these cells has demonstrated the presence of beta-adrenoreceptors with two different affinities. The dissociation constants (Kd) have been found to be 0.27 +/- 0.09 x 10(-9) M and 2.96 +/- 0.31 x 10(-9) M, respectively with the corresponding Bmax of 5.1 +/- 0.05 and 70.0 +/- 0.2 pmol/mg protein, respectively. Inhibition of [3H]DHA binding to the beta-receptor by atenolol (a beta 1-antagonist) and ICI 118,551 (a beta 2-antagonist) has suggested that the IC50cor (= Ki) for atenolol and ICI 118,551 for high affinity site are 0.08 +/- 0.03 x 10(-12) M and 0.25 +/- 0.08 x 10(-12) M, respectively. This, therefore, indicates that both atenolol and ICI 118,551 are able to displace the bound ligand effectively but the beta 1-selective antagonist atenolol is 3 times more potent than its beta 2 counterpart, ICI 118,551. Displacement of [3H]DHA binding to the endothelial cell plasma membrane by the agonists isoproterenol, epinephrine and norepinephrine has established a relative order of Ki for these agents as isoproterenol (0.56 +/- 0.19 x 10(-9) M) < epinephrine (0.77 +/- 0.26(-9) M) > or = norepinephrine (0.71 +/- 0.24 x 10(-9) M) for the high affinity site. The corresponding values for the low affinity site, however, are 4.62 +/- 0.64 x 10(-9) M, 6.21 +/- 0.86 x 10(-9) M and 5.90 +/- 0.82 x 10(-9) M, respectively for the same agonists. Increased intracellular cAMP accompanied with cellular proliferation in the presence of isoproterenol has suggested not only the coupling of beta-adrenoreceptors to the adenylate cyclase system but also its involvement in endothelial cell proliferation.

Substituent effects on the genotoxicity of 4-nitrostilbene derivatives

4-Nitrostilbene and twelve of its derivatives (eleven E-stilbenes and two Z-stilbenes) were examined for possible quantitative structure-activity relationships of their in vitro and in vivo genotoxicity. Relative mutagenicity was studied with and without S9 activation in Salmonella strains TA98 and TA100, as well as in the nitroreductase deficient strains TA98/NR and TA100/NR. Chromosomal aberrations in the bone-marrow cells of mice following intraperitoneal administration of the nitrostilbenes were observed as an indicator of in vivo genotoxicity. All of the compounds were active in TA98 and TA100 without S9 activation, with the exception of 4-amino-4'-nitrostilbene in TA100. Mutagenic activity was greatly reduced or eliminated in the NR strains, which is consistent with metabolic activation of the compounds by bacterial reductase. The presence of S9 lowered the activity of most of the nitrostilbenes presumedly by enzymatic detoxication. Hammet values of substituents, partition coefficients and frontier orbital energies (ELUMO and EHOMO) were studied for correlations with mutagenicity of the eleven E-stilbenes. Correlations could be established between mutagenicity in TA98 without S9 activation and the Hammet values. The same mutagenicity could also be correlated to ELUMO. Rationales for these correlations include the concept that electron-withdrawing groups which lower ELUMO should facilitate the reduction of the nitro group, leading to the proximate mutagen hydroxylamine. The correlations are also explained by the concept that electron-withdrawing groups should help stabilize the hydroxylamine intermediate and make the ultimate mutagenic species, the nitrenium ions, more reactive toward DNA. The relationship between mutagenicity and electronic effects of substituent groups found in vitro could not be extended to the in vivo results. However, except for the dinitrostilbenes, where insolubility prevented their testing, all the nitrostilbenes produced a statistically significant increase in chromosomal aberrations compared to the negative solvent control.

Handigodu disease: a radiological study. A new variety of spondyloepi(meta)physeal dysplasia of the autosomal dominant type

Handigodu disease is a new syndrome of familial spondyloepi(meta)physeal dysplasia. It is inherited as an autosomal dominant trait. The disease is prevalent in a localised area of South India. On the basis of detailed clinical, anthropometric and radiological investigations of 234 affected individuals, it has been observed that different clinical presentations reflect variation in the severity of the disease. All of them could be explained as being caused by defective development of bones as a result of monogenic disorder.

Safety and decision support in oncology

The management of patients with cancer involves the administration of complex treatment protocols with frequent monitoring of the effects of treatment on the malignant disease as well as on the general health of the patient. The number and wide variety of protocols used in treatment trials, and the amount of clinical data generated suggest the need for computer-based support. The toxicity of many of the treatments used and the severity of the disease itself underline the safety-critical nature of all decisions made by oncologists, the physicians and surgeons who treat cancer patients. This paper presents recent work on the analysis of safety issues arising from the design and implementation of a prototype decision-support system for oncologists. It illustrates the benefits of combining both informal and formal approaches to the analysis and representation of safety, firmly based on a thorough and detailed study of the domain in cooperation with oncologists, pharmacists and medical informaticians.

Absence of HTLV-I infection in some Indian populations

A total of 946 adults belonging to ten population groups of Uttar Pradesh and West Bengal were screened for HTLV-I using a gelatin particle agglutination test. The percentage of seroreactive cases varied from 0 to 5.8 per cent. The overall prevalence of seroreactivity was 2 per cent. Of the 19 seroreactive cases, 15 were subjected to Western blot analysis, none could be confirmed. HTLV-I infection is, therefore, absent in these populations.

Low-molecular weight heparin versus aspirin and dipyridamole after femoropopliteal bypass grafting

Low-molecular weight heparin has theoretical advantages over aspirin and dipyridamole in maintaining vascular-graft patency by virtue of its better antithrombotic effect and antiproliferative activity on vascular, smooth-muscle cells. We tested the hypothesis that low-molecular weight heparin would be more effective than aspirin and dipyridamole in maintaining graft patency in patients undergoing femoropopliteal bypass grafting. Patients were randomised to receive either a daily injection of 2500 IU low-molecular weight heparin, or 300 mg aspirin with 100 mg dipyridamole 8 hourly for 3 months. 94 patients were randomised to low-molecular weight heparin and 106 to aspirin and dipyridamole. Patients were stratified according to indication for surgery and were followed up for 1 year. Kaplan-Meier estimate of graft patency showed 87% graft survival on low-molecular-weight heparin and 72% on aspirin and dipyridamole at 6 months. At 12 months, the respective figures were 78% and 64%. Stratified survival analysis showed that this benefit was confined to those having salvage surgery (log rank test p = 0.0006); for those having surgery for claudication there was no significant benefit. No major bleeding events occurred in either group. We conclude that low-molecular weight heparin is better than aspirin and dipyridamole in maintaining femoropopliteal-graft patency in patients with critical limb ischaemia undergoing salvage surgery. This treatment should have considerable cost benefits.

Differential regulation of heparin-binding epidermal growth factor-like growth factor in the adult ovariectomized mouse uterus by progesterone and estrogen

Expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) was studied in the adult ovariectomized mouse uterus in response to progesterone (P4) and/or 17 beta-estradiol (E2) using Northern blotting, in situ hybridization, and immunohistochemistry. A 2.5-kilobase transcript of HB-EGF messenger RNA (mRNA) was detected in total uterine RNA samples. Although low levels of this mRNA were detected in uterine samples of oil-treated ovariectomized mice (control), an injection of E2 promptly up-regulated the levels. The mRNA levels peaked at 2 h and returned to basal levels after 12 h. Injection of P4 alone did not influence the basal levels; however, coinjection of E2 with P4 caused a rapid, but transient, up-regulation of the mRNA. The levels peaked between 2-4 h and declined 6 h after the hormone injections. Coinjection of E2 with P4 after 1 day of P4 priming also resulted in peak levels of HB-EGF mRNA at 2 h; however, the levels were not sustained thereafter. Because P4 and E2 differentially regulate heterogeneous uterine cell types, in situ hybridization was performed to determine cell-specific expression of HB-EGF mRNA in the ovariectomized uterus before and after steroid treatments. In the oil-treated uterine sections, very low levels of autoradiographic signals were observed in the luminal epithelium. In contrast, an injection of E2 resulted in a marked accumulation of HB-EGF mRNA primarily in uterine epithelial cells within 2 h. Although specific hybridization signals could not be detected in any uterine cell types after P4 treatment, combined treatment with P4 and E2 resulted in an accumulation of HB-EGF mRNA in stromal cells. To determine whether uterine HB-EGF mRNA was translated, cellular distribution of HB-EGF protein was investigated by immunohistochemistry. In oil-treated uterine sections, an overall weak immunostaining was noted, whereas no staining could be detected in uterine sections after P4 treatment. In contrast, positive immunostaining was noted in epithelial cells after E2 treatment. Coinjection of P4 with E2 caused immunostaining in the stroma. These results are consistent with those of in situ hybridization. The present investigation establishes that in the adult ovariectomized mouse uterus, E2 regulates HB-EGF expression in the epithelium, whereas expression of HB-EGF in the stroma is regulated by P4 and E2.

A vaccine that prevents pregnancy in women

We report here results of clinical trials on a birth control vaccine, consisting of a heterospecies dimer of the beta subunit of human chorionic gonadotropin (hCG) associated noncovalently with the alpha subunit of ovine luteinizing hormone and conjugated to tetanus and diphtheria toxoids as carriers, that induces antibodies of high avidity (K(a) approximately 10(10) M-1) against hCG. Fertile women exposed to conception over 1224 cycles recorded only one pregnancy at antibody titers of > 50 ng/ml (hCG bioneutralization capacity). The antibody response declines with time; fertility was regained when titers fell to < 35 ng/ml. This study presents evidence of the feasibility of a vaccine for control of human fertility.

Expression of epidermal growth factor receptor in the preimplantation uterus and blastocyst of the western spotted skunk

The western spotted skunk is unique in that its blastocysts undergo a 180-220-day period of arrested development before implantation. We investigated the potential role of epidermal growth factor (EGF)-related growth factors in regulating uterine and embryonic development in this species by studying the status of EGF receptor (EGF-R) in these tissues during delayed implantation and resumption of embryonic development. The cell-specific distribution of EGF binding sites and the expression of EGF-R mRNA were assayed by autoradiography and Northern blot analysis, respectively. The size of EGF-R was determined by affinity cross-linking studies, and its bioactivity was examined by determining EGF-dependent subcellular protein tyrosine kinase (PTK) activity. EGF binding sites were localized in the uterine luminal and glandular epithelium, endometrial stroma, myometrium, and blood vessels during both stages of pregnancy. As examined by Northern blot hybridization, a cRNA probe specific to mouse EGF-R hybridized to poly(A)+ RNA of skunk uteri. Transcripts similar to those of mouse uterine EGF-R were identified. [125I]-EGF was cross-linked to a 170-kDa protein both in the uterus and in blastocysts collected during the delayed implantation and periimplantation periods. However, EGF-induced PTK activity was significantly elevated above background levels during the period of renewed embryonic development, but not during arrested embryonic development. The results suggest that EGF-related growth factors may play an important role in regulating embryonic development in this species and that a change in the number and/or functional status of the EGF-R may be a prerequisite for blastocyst activation and implantation in the spotted skunk.

Heparin-binding EGF-like growth factor gene is induced in the mouse uterus temporally by the blastocyst solely at the site of its apposition: a possible ligand for interaction with blastocyst EGF-receptor in implantation

Heparin-binding EGF-like growth factor (HB-EGF) is a newly discovered member of the EGF family of growth factors. HB-EGF can bind to two loci on cell surfaces, heparan sulphate proteoglycans and EGF-receptor (EGF-R), and either one or both of these interactions could play a role in cell-cell interactions. In the rodent, increased endometrial vascular permeability at the site of blastocyst apposition is considered to be an earliest discernible prerequisite event in the process of implantation and this event coincides with the initial attachment reaction between the blastocyst trophectoderm and uterine luminal epithelium. This investigation demonstrates that the HB-EGF gene is expressed in the mouse uterine luminal epithelium surrounding the blastocyst 6–7 hours before the attachment reaction that occurs at 2200–2300 hours on day 4 of pregnancy. It was further demonstrated that this gene is not expressed in the luminal epithelium at the site of the blastocyst apposition during the progesterone-maintained delayed implantation, but is readily induced in the luminal epithelium surrounding an activated blastocyst after termination of the delay by an estrogen injection. In vitro studies showed that HB-EGF induced blastocyst EGF-R autophosphorylation, and promoted blastocyst growth, zona-hatching and trophoblast outgrowth. These results suggest possible interactions between the uterine HB-EGF and blastocyst EGF-R very early in the process of implantation, earlier than any other embryo-uterine interactions defined to date at the molecular level.

Distribution of transforming growth factor alpha precursors in the mouse uterus during the periimplantation period and after steroid hormone treatments

Temporal and cell-type specific distribution of transforming growth factor alpha (TGF alpha) precursor (proTGF alpha) was examined in the mouse uterus during the periimplantation period, and after steroid hormone treatments of ovariectomized adult mice by immunohistochemistry using antibodies that recognize the precursor forms of the growth factor. These studies were complemented by immunoblot analysis of proTGF alpha in separated uterine cell-type preparations. The specificity of the antibodies used in these studies was confirmed by use of pancreas or lactating mammary glands from transgenic mice in which mutated proTGF alpha, lacking recognition sites for proteolytic cleavages, was targeted for expression under a tissue-specific enhancer/promoter. Analysis of histochemical studies revealed accumulation of immunoreactive proTGF alpha primarily in luminal and glandular epithelial cells on Day 1 of pregnancy or pseudopregnancy followed by little or no accumulation on Days 2 and 3. However, immunoreactive proTGF alpha started to reappear in the luminal epithelium on the morning of Day 4 and became more prominent in the afternoon. In pregnant mice, immunostaining persisted in these cells at the implantation sites during the time of attachment reaction (2130 h on Day 4), but disappeared by morning of Day 5. Immunostaining appeared to be situated at the apical border of the luminal epithelium. No positive immunostaining could be detected in the nonreceptive uterus on Day 5 or 6 of pseudopregnancy. Consistent with the immunohistochemistry results, Western blot analysis detected two species of precursor proteins (14.5 and 17 kDa) in isolated luminal epithelial cell-enriched preparations on Day 4, but not on Day 5, of pseudopregnancy. The results suggest that proTGF alpha accumulates in the luminal epithelium of the receptive uterus prior to implantation. The effects of ovarian steroids on uterine accumulation of proTGF alpha were examined in ovariectomized adult mice by immunohistochemistry and immunoblotting. Whereas an injection of estradiol-17 beta (E2) or progesterone (P4) had little or a modest effect on epithelial accumulation of proTGF alpha, P4 priming for several days resulted in distinct accumulation of proTGF alpha in epithelial cells. The superimposition of an E2 treatment on P4 priming showed a biphasic response, with an initial gradual loss of immunostaining through 12 h followed by a return by 24 h of E2 treatment. The combined hormone treatment schedule employed here is similar to the situation of inducing implantation with E2 in P4-primed delayed implanting mice. The results suggest a paracrine/"juxtacrine" role for this growth factor in implantation.

Development of pancellular toxicity in guinea pig lung by ingestion of oleylanilide

Toxic oil syndrome (TOS), characterized by widespread thromboembolism, vasculotoxicity, and ARDS, develops in humans ingesting denatured edible oils. The mechanism(s) involved in targeted vasculocentric damage in this multi-system disorder is not known. Oleylanilide (OA) was synthesized and fed to male, young adult guinea pigs by gavage for 30 days at doses of 35, 50, and 100 mg/kg/day in groups of six animals each respective to weight. Controls were fed olive oil. Oleylanilide fed animals gained less weight than controls. At the end of experiment, right lungs were inflation fixed in appropriate fixative for histology and transmission electron microscopy (TEM) and left lungs were frozen at -70 degrees C for biochemical analyses. The activity of glycerophosphate acyltransferase (GAT) and cholinephosphotransferase (CPT), two key enzymes involved in phospholipid biosynthesis, were decreased in lung due to OA ingestion. All doses of OA induced marked perivascular and peribronchoiolar monocytic infiltrates that often formed prominent nodules; segmental vascular smooth muscle cell proliferation and derangement of myocytic polarity, subendothelial foamy infiltrates, and edema; nuclear pyknosis and dropout in vascular and bronchial targetoid myocytes; and denudation of bronchiolar epithelial cells. Alveoli contained large numbers of monocytes, macrophages, red cells, edema, and debris. Transmission electron microscopy showed type I cell cytoplasmic ballooning and disintegration of type I cell; contracted and blebbed endothelial cells, fibrin thrombi in capillaries, intracellular megalamellar bodies in type II cells, and surfactant lamellae; and liposomes and fine granular precipitates within alveoli, and contraction and lift off of bronchiolar epithelial cells. Monocytes, mast cells, and eosinophils infiltrated bronchial walls. Furthermore, there was deposition of electron dense particles on the surface of the alveolar wall.(ABSTRACT TRUNCATED AT 400 WORDS)

Differential expression of epidermal growth factor receptor (EGF-R) gene and regulation of EGF-R bioactivity by progesterone and estrogen in the adult mouse uterus

The present study examined several aspects of epidermal growth factor receptor (EGF-R) in the mouse uterus during the peri-implantation period and after ovarian hormone treatment of adult ovariectomized mice. The cell-specific distribution, regulation of expression, and binding kinetics were assessed by immunohistochemistry, Northern blot analysis, and ligand binding assays, respectively. Affinity cross-linking studies ascertained the size of the EGF-R, and its bioactivity was examined by determining EGF-dependent subcellular protein tyrosine kinase activity and receptor autophosphorylation. In the intact uterus and separated cell types, EGF-R was detected in the stroma, deciduum, and myometrium, but not in the luminal or glandular epithelium. Uterine EGF-R mRNA transcript profiles showed some differences between pregnant and ovariectomized mice regardless of steroid hormone treatments. Two major [6.5- and 2.7-kilobase (kb)] and two less abundant (9.6- and 5.0-kb) transcripts were detected in pregnant uterine poly(A)+ RNA. Three additional transcripts (< 2.0 kb) were detected in decidual poly(A)+ RNA, and a larger transcript (8.0 kb) was detected in uterine poly(A)+ RNA isolated from ovariectomized mice. Scatchard analysis of EGF binding also revealed apparent differences in binding kinetics between pregnant and ovariectomized mice, although EGF was cross-linked to a 170-kilodalton protein under these conditions. Two classes (Kd, approximately 0.2 and approximately 2.0 nM) of binding sites were noted in pregnant mice, whereas a single class (Kd, approximately 1.0 nM) was found in ovariectomized mice. 17 beta-Estradiol (E2) caused a rapid transient upregulation of uterine EGF-R mRNA levels and increased the number of EGF-binding sites in ovariectomized mice, as did an injection of progesterone (P4). However, the bioactivity of EGF-R could not be detected in uteri of ovariectomized mice treated with oil or P4. E2 treatment was found to be essential for EGF-R bioactivity. Taken together, the results suggest that in the adult mouse uterus, EGF-R status is influenced by factors other than P4 and E2, the epithelium is not the direct target for the actions of EGF-related growth factors as thought previously, the mitogenic effects of these growth factors on epithelial cells in vivo are perhaps mediated by other uterine cell-types expressing EGF-R, and, lastly, these growth factors are not likely to be functional in the uterus in the absence of estrogen. The present observations are supportive of the concept of paracrine or juxtacrine interactions between EGF-related growth factor ligands of luminal epithelial origin and blastocyst EGF-R in the process of implantation.

Toxic effects of fatty acid anilides on the oxygen defense systems of guinea pig lungs and erythrocytes

Toxic oil syndrome (TOS) is caused by ingestion of denatured edible oils. Even though the etiology and pathogenesis of this disease are not fully known, it is quite clear that generation of free radicals caused by ingestion of fatty acid anilides is responsible for the pathogenetic mechanism in many TOS patients. Fatty acid anilides may also alter the free radical status of lungs and erythrocytes; this possibility may shed some light on understanding toxic oil syndrome. The present study describes the effects of oral administration of fatty acid anilides on the activities of major enzymes involved in the oxygen defense systems of lungs and erythrocytes. Feeding fatty acid anilides caused an increase in the superoxide dismutase (SOD) activity in erythrocytes, whereas it caused a decrease in the SOD activity in lungs. GSH-Px activity was not significantly changed in erythrocytes but was decreased in lungs. Although the activity of catalase was increased only by a higher dose in the erythrocytes, it was not affected in the lung at any dosage. Even though the ingestion of fatty acid anilides caused an increase in the SOD activity in the erythrocytes and a decrease in the SOD activity in the lungs, there was an increase in the lipid peroxidation in both cases. The increase in lipid peroxidation in erythrocytes is probably caused by the accumulation of H2O2, and that in the lungs is due to the accumulation of superoxide anion.

Substituent effects on the in vitro and in vivo genotoxicity of 4-aminobiphenyl and 4-aminostilbene derivatives

4-Amino-4'-substituted biphenyls and 4-aminostilbenes substituted in the 3' or 4' position were studied for their in vitro and in vivo genotoxicity. The in vitro mutagenicity of the biphenyls with and without S9 activation was established with Salmonella strains TA98 and TA100 and that of the stilbenes with the same strains plus TA98/1,8-DNP6. The in vivo genotoxicity assay with both series of compounds was for chromosomal aberrations in the bone-marrow cells of mice following intraperitoneal administration of the chemicals. Hammett values of substituents, partition coefficients and frontier orbital energies (ELUMO and EHOMO) of the compounds were used for correlations with mutagenicity. The Salmonella mutagenicity in TA98 and TA98/1,8-DNP6 with S9 was correlated to Hammett sigma + values for the 4-aminostilbene substituents, showing a strong trend of increasing mutagenicity with an increase in the electron-withdrawing capability of the substituent. Hydrophobicity of the stilbenes, however, had little effect on their relative mutagenicity. The 4-aminobiphenyls showed a correlation between their mutagenicity and Hammett sigma + values of their 4'-substituents in stain TA98 with S9, although the trend was not as strong as for the stilbenes. But unlike the stilbenes, TA98 mutagenicity of the biphenyls could also be correlated to hydrophobicity, and structure-activity correlations for the biphenyls was substantially improved when both sigma + and hydrophobicity data were included. For strain TA100 with S9, little correlation was found between mutagenicity of the stilbenes and any of the parameters. However, a limited correlation did exist between the mutagenicity of the biphenyls and their hydrophobicity. There was also limited correlations of the mutagenicity for the stilbenes in TA98 and TA98/1,8-DNP6 with S9 to ELUMO or EHOMO. The in vivo genotoxicity results for the biphenyls and stilbenes could not be correlated to electronic effects as for the in vitro results, nor could they be explained by hydrophobicity. However, it is interesting to note that 3'-substituted 4-aminostilbenes were all substantially more genotoxic in vivo than their corresponding 4'-substituted counterparts. The most genotoxic compound in vivo in either series was 4-aminostilbene which would not have been predicted from the in vitro results.

Current status of topical antithrombotic agents in microvascular surgery

Several technical advances over the years have allowed microsurgery to be successful. However, thrombosis, particularly at the anastomosis site, remains a complication of microvascular surgery. Various preventive measures, including drugs, have been used to improve microvascular surgical anastomotic patency rates. The purpose of this article is to review the literature and the current status of topical antithrombotic agents. From this review along with laboratory investigations it is concluded that a combination of topical as well as systemic agents offers the best patency rates. However, the "ideal" antithrombotic agent is yet to be discovered and investigations need to be continued in order to improve or eliminate the complication of microvascular thrombosis. But the importance of atraumatic technique cannot be overemphasized.