PHA activation of encephalitogenic T cells: in vitro line selection overcomes splenic suppression

In this study we compared myelin basic protein (MBP) and phytohemagglutinin (PHA) for their ability to induce proliferation and experimental autoimmune encephalomyelitis (EAE) transfer activity in mixed cell cultures obtained from spleen and lymph nodes versus highly selected MBP-specific T cell lines and clones. Established MBP-specific cells derived initially from immune lymph nodes attained both proliferative and EAE-transfer activities after in vitro activation with either MBP or PHA. In contrast, PHA was unable to induce immune spleen cells to transfer EAE, in spite of its potent mitogenic activity. On the basis of these results, we evaluated the in vitro proliferation and differentiation responses of MBP-specific T cells during the line selection process using cells derived from both immune lymph node and immune spleen. During the initial selection process with MBP, proliferation of MBP-specific T cell precursors from immunized spleen populations was reduced relative to lymph node cells. After antigen-dependent selection the encephalitogenic cells from either organ exhibited identical in vitro response characteristics. Freshly isolated immune spleen cells were potent suppressors of MBP-specific T cell proliferation suggesting that the in vitro differences between the two organs was due to splenic suppression of the encephalitogenic cells.

Phosphatidylcholine synthesis in human spermatozoa

To clarify the mechanism of phospholipid synthesis in spermatozoa, fresh human spermatozoa were incubated with labeled fatty acids and 1-acyl-lysophosphatidyl choline (LPC) in the presence or absence of coenzyme A (CoASH). Both docosahexaenoic acid and palmitic acid were incorporated into phosphatidylcholine; however, this reaction was absolutely dependent upon the presence of CoASH in the incubation medium. The rate of incorporation of docosahexaenoic acid was 2.7-fold higher than that of palmitic acid, but more palmitic acid was incorporated into phosphatidylcholine in the absence of LPC. These data provide direct evidence for acyl transferase activity in human spermatozoa and may furnish a mechanism for phospholipid remodeling in sperm membranes. The different incorporation rates of these fatty acids into phosphatidylcholine may be due to the kinetics of the activation step, long chain fatty acid:CoASH ligase (AMP), or the substrate specificity of the acyl transferase.

Improved safety factor for triphasic defibrillator waveforms

Newly developed biphasic waveforms improve defibrillation efficacy both by reduction of defibrillation threshold and by amelioration of shock-induced dysfunction depending on the relative shape of the first and second pulses. Each of these independent effects improves the waveform's safety factor, the ratio between the shock intensity that produces a specific degree of postshock dysfunction and the shock intensity that produces defibrillation (or cellular excitation). Symmetrical waveforms reduce defibrillation threshold to about 60% that of the corresponding monophasic waveform, probably by reduction of excitation threshold for ischemic cells, but increase postshock arrhythmias. Biphasic waveforms with 10% "tails" reduce postshock arrhythmias. This study tests the hypothesis that these independent mechanisms for improvement of defibrillation efficacy can be combined into a single triphasic waveform that will have a higher safety factor than either of the two biphasic waveforms of which it is composed. Cultured myocardial cells were subjected to high-intensity electric-field stimulation with a control monophasic rectangular waveform, a symmetrical biphasic waveform, and a triphasic waveform consisting of the biphasic waveform with an added 10% "tail." Each waveform portion was 5 msec in duration. Photocell mechanograms monitored contractile activity. We found that the duration of postshock arrest of spontaneous contractile activity increased with stimulus intensity for all waveforms. The voltage gradient producing a 4-second arrest after the biphasic waveform shock was 80.6 +/- 1.3% that of the control waveform (100%), while the voltage gradient for the triphasic waveforms was 87.1 +/- 0.73% of control. The difference between biphasic and triphasic waveforms was significant (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

The administration of pharmacological doses of testosterone or 19-nortestosterone to normal men is not associated with increased insulin secretion or impaired glucose tolerance

Excess androgen secretion and exogenous androgen administration may decrease insulin sensitivity and impair glucose tolerance. We examined the responses to an oral glucose tolerance test in 30 normal men before and after 6 weekly injections of androgen administered in a double-blinded study design. The men were randomly assigned to 1 of 4 treatment groups: testosterone enanthate (TE), 100 or 300 mg/week, or 19-nortestosterone decanoate (ND), 100 or 300 mg/week. Serum testosterone levels, measured 2-3 days after the last dose, did not change in the men given 100 mg TE/week, increased 3-fold in those given 300 mg TE/week, and decreased in both ND groups. All four groups had comparable reductions in serum LH levels. Weight increased significantly in all except the 100 mg TE/week group, but there was no change in waist to hip ratio in any group. In spite of the demonstrated biological effects of the doses of steroid administered, androgen administration for 6 weeks did not increase fasting serum glucose or insulin concentrations. There was also no increase in peak serum insulin levels and areas under the insulin and glucose response curves after a 100-g oral glucose load. However, the mean serum insulin area under the curve decreased significantly in the men given 300 mg ND/week. In contrast to the results of studies of 17-alkylated androgens, our results demonstrate that pharmacological doses of testosterone and the administration of 19-nortestosterone for 6 weeks do not impair glucose tolerance or alter insulin secretion in normal men.

Oviductal, not oviducal

Both etymologically and in literal meaning the term "oviductal" is overwhelmingly preferable to "oviducal."

Selection of encephalitogenic rat T-lymphocyte clones recognizing an immunodominant epitope on myelin basic protein

Using the soft agar-cloning technique, we isolated 13 T-cell clones from guinea pig basic protein (GP-BP)-specific T-cell lines derived from Lewis rats. The clonal frequency was approximately 2.5 x 10(-5). Each of these clones had a similar but not identical pattern of response to a battery of synthetic peptides representing overlapping epitopes in the encephalitogenic region for Lewis rats (69-89 sequence). All clones responded to the minimal encephalitogenic sequence (residues 72-84) restricted by I-A but not I-E molecules, and all transferred clinical experimental autoimmune encephalomyelitis (EAE) and delayed-type hypersensitivity (DTH) reaction to naive rats. Phenotypically, the clones were W3/13+ (total T), W3/25+ (T helper), and OX-22+ (DTH associated). This report demonstrates for the first time the applicability of the soft agar-cloning technique for obtaining encephalitogenic T-cell clones. The exclusive recovery of 72-84-specific T-cell clones after only two rounds of stimulation with GP-BP indicates the immunodominance of this epitope and the power of the line selection technique for obtaining encephalitogenic T-cell specificities.

Immunohistologic demonstration of platelet-derived growth factor (PDGF) and sis-oncogene expression in scleroderma

Although the pathogenesis and mechanisms responsible for excessive connective tissue deposition are not known, it has been thought that specific growth factors may have an effect on scar formation by increasing the fibroblast population and by affecting the amount and types of matrix synthesized. In this regard, we explored the appearance and localization of TGF alpha, TGF beta, PDGF, and sis-onc expression in situ. Sections of skin biopsies from eight scleroderma patients were investigated using specific antibodies to TGF alpha, TGF beta, human PDGF, and sis-onc products for immunohistochemistry. Most significantly, deposition of PDGF was detected in the endothelial lining of small capillaries in association with certain mononuclear cells of the perivascular infiltrates. In particular, strong labeling was observed in the cytoplasm of macrophages. Smooth muscle also appeared to be specifically labeled. Similarly, sis-onc product localized in the same areas. No significant staining was observed with antibodies to TGF alpha. TGF beta was found rather diffusely throughout the dermal connective tissue and was only occasionally observed in capillaries of lesions. We conclude that the PDGF may play an important role in the pathogenesis of scleroderma.

Host Plants, Temperature and Seasonal Effects on Immature Development and Adult Size of Euploea-Core-Corinna (Lepidoptera, Danainae)

The suitability of four commonly used host plants of Euploea core, i.e. Cryptostegia grandiflora, Hoya australis, Nerium oleander and Parsonsia straminea, was measured in terms of developmental rates, pupal weight and adult wing length. The experimental temperature and seasonal quality of fresh shoots of the host plant affected all these variables. The results of development rates were inconsistent across host plants at different temperatures, but pupal weight and wing length of the butterfly were consistent. Despite great differences in the weight of pupae, pupal developmental rates appeared mainly affected by temperature. Fresh foliage produced in early spring gave significantly better growth of larvae than fresh foliage produced in late spring or autumn. Larvae coped with poor food quality in two distinct ways. One group moulted at approximately the right time, but at an unusually small size, the other group delayed moulting until it reached an appropriate size for moult. Losses were heavy in both groups. Overall, host plants in the Apocynaceae were more suitable for growth than those in the Asclepiadaceae, but whether the host plants were introduced or native, or whether they contained copious quantities of latex or not, did not seem to have a significant effect. The successful use of host plants in the Asclepiadaceae, like the C. grandiflora and ornamental H. australis, is therefore probably related to other factors, such as the frequency with which they produce fresh foliage and their common presence, overriding any minor differences in suitability. Key words: Euploea, developmental rates, host plants, seasonal effects.

Breast-feeding and post-partum amenorrhoea in Indonesia

The association between breast-feeding patterns and resumption of menses post-partum was examined in a prospective study in Indonesia. In order to examine these relationships directly in a longitudinal study, it was first necessary to distinguish among women who experienced infant mortality before menses resumed, women who weaned before menses resumed, and women who had return to menses while breast-feeding. Information on suckling patterns and menstrual status was collected by recall for 444 women at monthly visits for 2 years. Three main breast-feeding variables, minutes per episode, number of episodes per day, number of episodes per night, and other breast-feeding variables were derived for each woman, to give the average nursing pattern up to menses or the end of the study, which-ever came first. While high levels of nursing for each of these three main variables were found to be significantly related to delay in return of menses post-partum, the interactions between more minutes per episode, and more frequent day- and night-time feeds, were found to be the most important factors in the delay in onset of post-partum menstruation in those women whose menses resumed while still nursing or who remained amenorrhoeic and nursing at the end of the study.

Pulmonary granuloma formation in murine toxocariasis: transfer of granulomatous hypersensitivity using bronchoalveolar lavage cells

A major drawback to studying granuloma formation in murine toxocariasis is the ability of the second-stage larva of Toxocara canis to escape from a developing granuloma, migrate elsewhere, and initiate granuloma formation anew. In an attempt to circumvent this difficulty, 2 different T. canis-derived antigenic preparations were covalently attached to Sepharose 4B beads and embolized into the microvasculature of the lungs of CBA/J mice that had been infected 10 days previously with 25 T. canis ova. Both T. canis egg extract (TEE) and T. canis exoantigens (TEX) were able to elicit antigen-specific granulomas 6 days postembolization as determined by both histologic and morphologic criteria. Histologically, the eosinophil-rich granulomas forming around antigen-coated beads embolized into infected mice resembled the developing granuloma previously described forming around the second-stage larva. Attempts to transfer granulomatous reactivity in this model using either immune spleen cells or immune serum were unsuccessful. Successful transfer of granulomatous hypersensitivity was achieved using cells obtained by bronchoalveolar lavage of previously infected mice. The results suggest the feasibility of using this embolic model of granuloma formation in murine toxocariasis.

Gonadotropin-induced ovulation in a reptile (Anolis carolinensis): histological observations

Although much is known about morphological changes in the apex of the mammalian ovarian follicle prior to its rupture (ovulation), information about this process in nonmammalian vertebrates is limited to only a few species. We describe here the histological changes in the stigma of the lizard (Anolis carolinensis) ovarian follicle preceding FSH-induced ovulation. Females with a large vitellogenic follicle received two injections, separated by 7 hr, of either porcine FSH (25 micrograms) or saline, and then were sampled at 6, 9, 12, 15, 18, and 24 hr after the first injection. Thus, all but the 6-hr group received two injections. By 12 hr, about half of the FSH-treated females had ovulated, and most had ovulated by 15 hr. In contrast, only 1 of 40 control females ovulated. Large unovulated follicles were fixed and bisected through the circular stigma; one hemisphere was embedded in paraffin and stained with Mallory's trichrome, and the other was embedded in plastic and stained with toluidine blue. FSH treatment produced marked histological changes in the stigma region, as well as alterations in nonstigmal areas of the follicle. The membrana granulosa of control follicles consisted of a single layer of squamous, darkly staining granulosa cells. After FSH treatment, nonstigmal granulosa cells separated slightly, and their nuclei became more clear and assumed an oval shape; in the stigma, these cells became widely separated, with round, light-staining nuclei containing one or two prominent nucleoli. The nonstigmal theca of FSH-treated follicles was similar to that of control follicles except that collagen fibers were more dissociated. In the stigma, collagen fibers were widely dissociated, and the theca swelled, presumably due to accumulation of extracellular fluid. Abundant fluid accumulated in the stigma, especially between the granulosa cells and their basement membrane and between the tunica albuginea and the theca externa. These changes in the lizard stigma are similar to those reported in mammals except that no marked inflammatory response occurs in the lizard stigma. We hypothesize that the Anolis follicle undergoes preovulatory luteinization, and that the stigma exhibits ischemic necrosis before rupture.

Inhibition of sex hormone-binding globulin production in the human hepatoma (Hep G2) cell line by insulin and prolactin

Sex hormone-binding globulin (SHBG) production in humans has been thought to be stimulated by estrogens and thyroid hormone and inhibited by androgens. However, recent data indicate that SHBG production in vitro is stimulated by both androgens and estrogens. This study was designed to determine what other hormonal factors regulate SHBG production. Since hyperinsulinemia and hyperprolactinemia both occur in disease states in which low serum SHBG levels are found, the effects of insulin and PRL were compared to and/or studied in combination with estradiol (E2), T4, and testosterone (T) in a human hepatoma cell line (Hep G2). Hep G2 cells were grown to near confluence in medium including 10% fetal calf serum, and then 72-h experimental incubations were carried out which used only fetal calf serum-free medium. Compared to control incubations, both insulin (10(-8) mol/L) and PRL (10(-8) mol/L) decreased SHBG production from 65.0 +/- 0.6 (+/- SE) to 46.8 +/- 1.1 and 46.8 +/- 1.2 nmol/10(6) cells, respectively (P less than 0.01). Insulin also inhibited both E2 and T4-stimulated SHBG production. T stimulated SHBG production to the same degree as E2. Finally, both E2 and insulin significantly increased cell number, an important consideration when expressing the effect of a hormone on SHBG production in cultured cells. We conclude that insulin and PRL inhibit SHBG production and confirm that T4, T, and E2 stimulate SHBG production in vitro. These findings suggest that insulin and PRL may be important factors in the regulation of SHBG production in vivo.

[Immunohistochemical studies of the histogenesis of dermatofibrosarcoma protuberans]

Paraffin-embedded tissue sections taken from 16 patients with dermatofibrosarcoma protuberans were stained by means of the peroxidase-antiperoxidase technique using antibodies against S 100 protein, NSE, Leu 7, lysozyme, alpha-1 antitrypsin, alpha-1 antichymotrypsin, cytokeratin, desmin, vimentin, and factor VIII. Most of the tumor cells showed positive reactions to vimentin. Only 1-3% of the cells within the tumor area answered to the histiocytic markers lysozyme, alpha-1 antitrypsin, and alpha-1 antichymotrypsin. The remaining antibodies investigated did not react with the tumor cells. Our results support a fibroblastic, and contradict a neural or histiocytic, histogenesis of dermatofibrosarcoma protuberans.

Evidence for the regulation of fatty acid utilization in human sperm by docosahexaenoic acid

The effects of stearic (18:0), linolenic (18:3), and docosahexaenoic (22:6) acids on palmitoyl coenzyme A (CoA) formation by a long-chain fatty acid:CoASH ligase (adenosine monophosphate) (E. C. 6.2.1.3-enriched fraction from human spermatozoa were studied. Both 18:0 and 18:3 were competitive inhibitors for palmitic (16:0) acid activation with Kis of 17.7 and 5.7 microM, respectively. In contrast, 22:6 was a noncompetitive inhibitor demonstrating a Ki of 9.5 microM. These data coupled with previous studies support the conclusion that 16:0, 18:0, and 18:3 and other saturated and unsaturated fatty acids are activated by the same ligase enzyme in sperm. Although the kinetics and interactions of 22:6 are unique compared to the other fatty acids found in sperm phospholipids, we cannot discern from our data if it is activated by a separate enzyme. We propose that 22:6, or a metabolite of 22:6, may regulate free fatty acid utilization in human sperm and that this hypothesis may provide an enzymatic explanation for the changes observed in phospholipid-bound fatty acids during the epididymal maturation of sperm.

Characterization of cloned human leukocyte 5-lipoxygenase expressed in mammalian cells

5-Lipoxygenase has been expressed in a mammalian osteosarcoma cell line transfected with the cloned cDNA for human leukocyte 5-lipoxygenase. Two clonal cell lines derived from the transfected cells expressed the enzymatic activity. When incubated with arachidonic acid (100 microM), the major 5-lipoxygenase products of 10,000 X g supernatants from these cells were 5-hydroxyeicosatetraenoic acid (5-HETE), and the nonenzymatic hydrolysis products of leukotriene (LT)A4. The ratio of 5-HETE to LT (between 6:1 and 9:1) was similar to that observed in leukocyte supernatants. Furthermore, incubation of 10,000 X g supernatants from the transfected cells with 5-hydroperoxyeicosatetraenoic acid (5-HPETE) (75 microM) resulted in the synthesis of LTA4 hydrolysis products. Control osteosarcoma cell supernatants produced no 5-HETE or LT from arachidonic acid or 5-HPETE. Maximal activity of the expressed enzyme required Ca2+, ATP, and two cellular stimulatory factors prepared from human leukocytes. Immunoblot analysis of supernatants from the osteosarcoma cell clones revealed an immunoreactive 80,000-dalton band that was indistinguishable from the band observed in leukocyte supernatants. Therefore, the expressed enzyme was functional and exhibited characteristics that were identical to those of human leukocyte 5-lipoxygenase. When intact transfected osteosarcoma cells were challenged with ionophore A 23187, no 5-lipoxygenase products were formed. If arachidonic acid was added along with the ionophore, the cells synthesized 5-HETE and the nonenzymatic hydrolysis products of LTA4. These results verify that the cDNA used to transfect the osteosarcoma cells encodes for 5-lipoxygenase. Furthermore, these studies offer independent evidence that this single protein possesses both 5-lipoxygenase and LTA4 synthase activity, as has been reported previously from enzyme purification data.

Splenectomy in hematologic disorders. The ever-changing indications

A comparison between a series of splenectomies performed at the University of Virginia Medical Center for hematologic disorders between 1946 and 1962 (Series I) and 1963 and 1982 (Series II) is presented. Four hundred splenectomies (20 per year) were performed between 1963 and 1982 compared with 94 (5.5 per year) between 1946 and 1962. Also noted in Series II was a sharp decline in the number performed each year between 1974 and 1983. The major factor responsible for these observations was the evolution of the staging laparotomy for malignant lymphomas, particularly Hodgkin's disease, and the decline in the average annual incidence of staging laparotomies since 1974. Staging laparotomy currently is rarely done for non-Hodgkin's lymphomas. Also contributing to the changes noted was an increase in the total number but subsequent fall in the annual incidence of splenectomy for hereditary spherocytosis, idiopathic hypersplenism, and myeloproliferative disorders in Series II. The average number of splenectomies for idiopathic thrombocytopenic purpura increased from 1.1 per year in Series I to 3.6 per year in Series II; the annual incidence during the study period of Series II, however, remained constant. The total number of splenectomies for hairy cell leukemia and Felty's syndrome increased from zero in Series I to 12 and 17, respectively, in Series II, whereas the number of miscellaneous reasons dropped from 29 (1.7 per year) in Series I to 15 (0.75 per year) in Series II. The mortality rate in Series I was 6.3% compared with 4.0% in Series II. No deaths occurred in Series II after 1979. Indications for splenectomy in Series II were for diagnostic purposes in 3.2%, therapeutic in 56.5%, staging in 39.5%, and restaging in 0.8%. Accessory spleens were found in 49 (12.5%) in Series II.

Primary gastric lymphoma. Problems in staging and management

A retrospective review of 28 patients with primary gastric lymphoma was performed to determine the optimal treatment modality. The presenting signs and symptoms resembled peptic ulcer disease or gastric carcinomas. The majority of the lymphomas were of the diffuse histiocytic subtype. There was a 75 percent resectability rate in those patients operated on. Palliative resection produced a 5 year duration of survival of 28 percent and curative resection, 43 percent. Eighteen patients underwent a subtotal gastrectomy, and a total of 10 patients presented with stage I disease. The longest median duration of survival at last follow-up was 32 months for patients with stage IB disease compared with a median duration of survival of 8 months for those with stage III disease. Adjuvant radiotherapy and chemotherapy may improve survival after a curative resection is performed if there is serosal penetration or nodal involvement.

Cloning of the cDNA for human 5-lipoxygenase

The enzyme 5-lipoxygenase (5-LO) catalyzes the first two reactions in the pathway leading to the formation of leukotrienes from arachidonic acid. Leukotrienes are potent arachidonic acid metabolites possessing biological activities that suggest a role in the pathophysiology of allergic and inflammatory diseases. To obtain structural information about 5-LO for use in developing anti-inflammatory chemotherapeutic agents, the enzyme was purified from human polymorphonuclear leukocytes and the amino acid sequences were determined for several cyanogen bromide-derived peptides. A cDNA clone encoding a 674-amino acid protein containing all of the derived peptide sequences was isolated from a dimethyl sulfoxide differentiated HL60 cell cDNA library. The mRNA encoding 5-LO was detected only in differentiated HL60 cells and not in the undifferentiated cell line, indicating that the expression of 5-LO in this cell line is transcriptionally regulated. In addition, the human protein displays some amino acid sequence homology with several lipases and significant homology with the partial sequences of soybean and reticulocyte lipoxygenases. Thus, 5-LO appears to be a member of a larger family of related enzymes.

Improved cardiac cell excitation with symmetrical biphasic defibrillator waveforms

According to the most commonly accepted hypothesis, ventricular defibrillation is produced by exciting cells in a critical mass of the ventricle. For monophasic defibrillator waveforms, this hypothesis correctly predicts a direct correlation between defibrillation threshold in the transthoracic calf model and excitation threshold for extracellular field stimulation in the cultured cell model. To further test the hypothesis, we determined whether symmetrical biphasic waveforms, which reduce defibrillation threshold in the calf to approximately 65% of that of the corresponding monophasic waveform (14), decrease excitation threshold in the cultured cell model. Experiments were performed on 100- to 250-microns aggregates from 10- to 12-day-old chick embryos. Excitation threshold strength-duration curves obtained at extracellular potassium (Ko) = 6.5 mM and pacing interval of 1,000 ms showed a significant reduction for symmetrical biphasic rectangular waveforms, when compared with the corresponding monophasic waveforms for durations greater than 3 ms. At the rheobase, the threshold ratio between the biphasic and monophasic waveforms was 0.63 (SE = 0.02). Transmembrane potentials during stimulation showed that excitation takes place during the second portion of the biphasic waveform for intensities that are subthreshold for the monophasic waveform. The relative effectiveness of the biphasic waveform (5-ms duration) increases under "fibrillation conditions" of short pacing interval (300 ms) and high extracellular potassium (10.5 mM). These results show that symmetrical biphasic waveforms decrease excitation threshold in the cultured cell model and that the degree of threshold reduction is dependent on Ko and beat rate.

Use of bronchoalveolar lavage to compare local pulmonary immunity with the systemic immune response of Toxocara canis-infected mice

Following infection of mice with larvae of the canine roundworm Toxocara canis, there is a persistent pneumonitis. Heretofore, nothing was known about the immunologic potential of the cells that constitute this inflammatory exudate. By performing bronchoalveolar lavage (BAL), enough inflammatory cells were obtained to compare the local pulmonary immune response to T. canis infection with the systemic immune response as reflected in the peripheral blood and spleen cells of the same mice. Groups of C57BL/6J female mice were given 100 infective ova and BAL, peripheral blood, and spleen cells collected on days 8, 11, 14, and 17 postinfection. The percentage of eosinophils in the BAL averaged about 80% and was four to five times as great as that in the peripheral blood at all times assayed. Use of concanavalin A (ConA)-elicited lymphocyte blastogenesis to evaluate T-lymphocyte activity revealed that BAL T-cell activity was low on day 8 and peaked on day 11. When the B-cell mitogen lipopolysaccharide was used in the assay, there appeared to be far less BAL cell reactivity compared with BAL T-cell activity. Both B- and T-cell responses of the BAL cells were only a fraction of the responses seen concurrently in spleen cells. Use of Toxocara exoantigens in the blastogenesis assay revealed that Toxocara exoantigens could elicit between 20 and 95% of the ConA response in BAL cells, while in spleen cells Toxocara exoantigens could only elicit 1 to 5% of the ConA response. These results suggest that BAL is a useful method for recovering local inflammatory cells that possess detectable immunologic activity. In the case of pulmonary toxocariasis, eosinophils account for the majority of the cells that are present, with most of the remaining cells being T. canis antigen-specific T lymphocytes.

Conservation of delta-crystallin gene structure between ducks and chickens

A cloned chicken delta-crystallin cDNA was used to identify two putative delta-crystallin genes in the duck by Southern blot hybridization. A DNA fragment containing most of one of these genes was isolated from a library made in bacteriophage lambda Charon 28A containing genomic DNA from 14-day-old embryonic ducks. Electron microscopy, partial gene sequencing, primer extension analysis using duck mRNA, and comparison with the well-characterized chicken delta-crystallin genes suggest that our cloned duck delta-crystallin gene, like the chicken delta-crystallin genes, is 8-10 kb long and contains 17 exons. Hybridization and sequencing data show great similarity between the homologous 5' untranslated and coding exons of the duck and chicken delta-crystallin genes. Overall, the homologous introns also appear to have approximately 30% sequence similarity, and have been subject to deletion/insertion events. Our partial characterization of duck delta-crystallin gene sequences suggests that this avian and reptilian crystallin family has been conserved during evolution, as have the other crystallin gene families that are expressed in the eye lens.

Microlesion formation in myocardial cells by high-intensity electric field stimulation

Arrhythmias, S-T segment changes, immediate refibrillation, and other signs of dysfunction are often observed after clinical and experimental transthoracic defibrillation. In vitro studies suggested that shock-induced dysfunction is induced by sarcolemmal dielectric breakdown accompanied by ionic exchanges through transient, shock-induced microlesions in the sarcolemma. To test this hypothesis, cultured chick embryo myocardial cells were shocked in media containing fluorescein isothiocyanate-labeled dextrans (FITC-dextrans) ranging in molecular mass from 4 to 70 kDa, using electric field stimulation 5 ms in duration and ranging in intensity from 0 to 200 V/cm. Results showed that the percentage of cells incorporating 4- to 20-kDa dextrans increased in a dose-dependent manner. The 4- and 10-kDa dextrans were incorporated beginning at intensities of 50-100 V/cm. Dextran incorporation corresponded with shock intensities which produced a shock-induced arrest of spontaneous contraction lasting 1 min. The 20-kDa dextrans were incorporated following 150- and 200-V/cm shocks. Shocks of these intensities also produced a transient postshock contracture. Larger dextrans (40 and 70 kDa) were not incorporated. These results suggest the formation of transient sarcolemmal microlesions having a diameter of 45-60 A during high-intensity electric field stimulation.

Seasonal changes in the effects of arginine vasotocin and stretch on Anolis uterine contractions in vitro

We determined the effects of acute stretch on spontaneous and arginine vasotocin (AVT)-driven contractions of the Anolis carolinensis uterus in vitro. Whole uteri from reproductively inactive females (October) were placed in a bath of oxygenated 32 degrees C Anolis "Ringer's." Two initial tensions were utilized, 1.5 g or 15 g, the latter being an estimate of the tension on the wall of a uterine compartment. Uteri were then exposed to either saline or AVT (50 ng/ml), and spontaneous or AVT-driven contractions were recorded for 20 min with the use of a strain gauge and physiograph. A similar experiment was performed on uteri from reproductively active females in the summer (June). Our results indicate that the effects of acute stretch and AVT on uterine contractility were qualitatively similar in summer and fall. That is, AVT induced a tonic contraction; stretch decreased the duration of the tonic contraction; the saline-treated uteri exhibited spontaneous rhythmic contractions; AVT increased the amplitude of the rhythmic contractions, but only at the lower tension; there were no effects of AVT on the timing (contraction interval, duration, rest interval) of the rhythmic contractions; and stretch increased the frequency of the rhythmic contractions. Season greatly influenced the magnitude of these contractile phenomena. Uteri tested during the breeding season exhibited greater distensibility, an increase in the amplitude and duration of the AVT-driven tonic contraction, and an increase in the frequency of both spontaneous and AVT-driven rhythmic contractions because of a decrease in both contraction duration and rest interval.(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral renal artery embolism: a diagnostic and therapeutic problem

A case of bilateral renal artery embolism in a patient occurring after coronary artery bypass operation is reported, describing the diagnostic techniques and therapeutic aspects of management of this unusual disease. The diagnosis should be suspected in patients with underlying cardiovascular disease who have acute renal failure.

Expression and secretion in yeast of a 400-kDa envelope glycoprotein derived from Epstein-Barr virus

The major envelope glycoprotein (gp350) of Epstein-Barr virus has been expressed and secreted in the yeast Saccharomyces cerevisiae as a 400-kDa glycoprotein. This is the first example of the secretion of such a large, heavily glycosylated heterologous protein in yeast. Since gp350 proved highly toxic to S. cerevisiae, initial cellular growth required repression of the expression of gp350. Using temperature- or galactose-inducible promoters, cells could be grown and the expression of gp350 then induced. After induction, the glycoprotein accumulated both intracellularly as well as in the culture medium. Only the most heavily glycosylated form was secreted, suggesting a role for N-linked glycans in directing secretion. The extent of O-linked glycosylation of the yeast-derived protein was similar to that of the mature viral gp350. N-linked glycosylation varied slightly depending upon culture conditions and host strain used and was more extensive than that associated with the mature viral gp350. Although there is no evidence that more than a single mRNA for the glycoprotein was expressed from the recombinant plasmid, variously sized glycoproteins accumulated in yeast at early stages after induction, probably reflecting intermediates in glycosylation. The yeast-derived glycoproteins reacted with animal and human polyclonal antibodies to gp350 as well as with a neutralizing murine monoclonal antibody to gp350, suggesting that this glycoprotein retains several epitopes of the native glycoprotein.

Temperature, Development and Survival in Monophagous and Polyphagous Tropical Pierid Butterflies

Development rates and juvenile survival of seven species of pierid butterfly from the Australian tropics were examined in laboratory conditions at a range of temperatures between 15 and 32�C. We studied three monophagous species, Eurema brigitta, E. laeta and E. herla, and four oligophagous or poly- phagous species, E. hecabe, E, smilax, Catopsilia pomona and Pieris (Artogeia) rapae; the last of these is the predominantly temperate cabbage butterfly, which has established a small tropical population on the Atherton Tableland in north Queensland. Larval and pupal stages of all species survived poorly at temperatures above 30�C, and most showed reduced survival below 22�C. Within their optimal temperature ranges, smaller species tended to survive better than larger ones. Oligophagous and polyphagous species developed more rapidly than monophagous ones, even though three of the former are larger than the latter. Development thresholds were between 10�C (for P. rapae) and 15�C (for C. pomona). There was little correlation between development threshold and latitudinal distribution, and we suggest that selection for the ability to develop relatively rapidly at lower temperatures may be influenced by the seasonal timing of the breeding season as well as by geographic distribution.

Nonoperative management of isolated grade III collateral ligament injury in high school football players

In a prospective study, 24 high school football players with isolated Grade III injuries of the medial collateral ligament (MCL) of the knee were treated by conservative management. This included an active rehabilitation program, progressing from immobilization and controlled motion in an orthotic rehabilitation knee brace, to muscle strengthening and agility exercise. A stable knee was achieved in 22 cases; the average recovery time was 29 days. The athletes returned to competitive sports at a mean time of 34 days. These results confirm previous reports of successful nonoperative management of isolated Grade III MCL injuries.

Kinetics of human spermatozoa long-chain fatty acid: CoASH ligase

The kinetics of long-chain saturated fatty acid activation were studied in the supernatant obtained from Triton-treated human spermatozoa. Sperm long-chain fatty acid: CoASH ligase (AMP) (E.C. 6.2.1.3) was able to activate myristic, palmitic, and stearic acids, but was incapable of utilizing lauric, arachidic, and behenic acids. Peak activity was obtained with palmitic acid. Although the Kms for each fatty acid were similar (4.3 to 5.0 microM), the Vmax was several-fold higher for palmitate. In contrast, ligase from liver homogenates assayed under identical conditions activated lauric through stearic acids, with maximal rates being noted with myristic acid. When compared with nongerminal tissues, sperm ligase appears unique because of its narrower acyl substrate specificity.

Prophylaxis with cefamandole nafate in elective orthopedic surgery

A prospective, randomized, double-blind study was conducted to determine the efficacy of cefamandole nafate in reducing infections in general orthopedic procedures. Of 743 patients initially entered into the study, 715 (362 on cefamandole, 353 on placebo) fulfilled the requirements of the protocol. The infection rate was 1.6% for the cefamandole-treated group and 4.2% for the placebo group. In operations lasting longer than two hours, there were two infections in the cefamandole group and seven infections in the placebo group (p less than 0.05). Staphylococcus aureus and gram-negative bacilli were the common pathogens. Adverse side effects were limited to transient elevations in liver enzymes.

Tracheal reconstruction with autogenous jejunal microsurgical transfer

Tracheal defects due to stricture formation, tracheomalacia, and neoplasms can present difficult reconstructive problems. Tracheal defects were surgically created in 6 dogs and primarily reconstructed with microsurgical free tissue transfer of autogenous jejunal segments. Primary healing was accomplished in all dogs without severe air leakage or infection. Bronchoscopy demonstrated no substantial secretions or tracheal narrowing. Gross pathological examination of the trachea revealed no evidence of tracheal disruption or infection. Direct measurements revealed no major tracheal narrowing. Microscopic examination demonstrated normal jejunal mucosa with a minimal amount of inflammatory change at the margins of the reconstruction at 6 weeks. Microvascular free tissue transfer of jejunal segments to correct cervical tracheal defects can readily be accomplished with excellent healing and maintenance of the tracheal lumen in dogs.

Light-induced interaction between rhodopsin and GTP-binding protein leads to the hydrolysis of GTP in the rod outer segment

In the presence of exogenous GTP, vertebrate whole rod outer segments (ROS), with perforated plasma membranes in the "single particle" scattering range, elicit a light-induced light-scattering transient which we call the "G" signal. Here, we report on the characteristics of the "G" signal relative to the "binding" and "dissociation" signals reported by Kuhn and colleagues. Replacing GTP with guanylyl imidodiphosphate (GMP-PNP) does not give rise to the G signal. This indicates that hydrolysis of the terminal phosphate is required for the G signal and, in addition, GTP and GMP-PNP compete for the same binding site of the enzyme responsible for the G signal (i.e., GTP-binding protein). Also, neither GDP nor its nonhydrolyzable analogue, guanosine 5'-O-(2-thiodiphosphate), when present in ROS suspensions yield any light-scattering transient in the time period tested.

Thyrotoxicosis associated with distant metastatic follicular carcinoma of the thyroid

In a man with metastatic follicular carcinoma of the thyroid, thyrotoxicosis developed after total thyroidectomy and was successfully treated with antithyroid medications. Treatment with radioactive iodine decreased the size of the distant metastasis and eventually diminished thyroid hormone production. Follicular carcinoma complicated by hyperthyroidism requires vigorous control of the hypermetabolic state. Treatment with radioactive iodine can effectively reduce metabolic complications and tumor bulk, and yields a remission rate as high as 33%.

Further discussion concerning porphyria cutanea tarda and TCDD exposure

Past reports have correlated a diagnosis of porphyria cutanea tarda (PCT) with exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Re-examination of the literature, however, has caused us to question the conclusion of a relationship between acquired PCT and TCDD. The major considerations at issue were: (1) whether the diagnostic label of PCT was applied excessively to cases with findings that are nonspecific; (2) whether the clinical conditions suggestive of PCT were the likely results of exposure to another chemical, for example hexachlorobenzene (HCB); and (3) whether a causal link between PCT and TCDD is reasonably substantiated by the facts. Based on the re-evaluation of the literature, the known effects of HCB and TCDD, and the follow-up results from the chemical plant, we submit that HCB alone, or HCB in combination with other polychlorinated aromatic hydrocarbons, may have been responsible for the effects observed and the subsequent correlation to PCT.

Activation of palmitic acid by human spermatozoa

Human spermatozoa were studied to determine if a long chain fatty acid, CoASH ligase (AMP) (E.C. 6.2.1.3), was present. Ligase activity was measured with a radioligand millipore filter technique and was readily detectable in spermatozoa or in the protein fraction extracted with Triton X-100, but was not present in seminal plasma. The assay was optimized for pH, protein concentration, and incubation time. Activity was dependent upon palmitic acid, ATP, coenzyme A, and a divalent cation. Sperm ligase appeared similar to the ligase characterized from other tissues by sharing a common pH optimum (approximately 8.0-8.4), and a preference for magnesium over manganese in the incubation media.

Multiple sclerosis: abnormalities in luminance, chromatic, and temporal function at multiple retinal sites

Visual function was assessed in a group of patients with multiple sclerosis (MS) and in a group of matched normal controls. In these patients the disease was relatively mild. For each subject, measures of a range of psychophysical visual functions were carried out at multiple sites in each eye. Previous reports have only included some of these functions. Here, luminance threshold, two-flash resolution, perceptual latency, luminance critical flicker frequency (CFF), and chromatic CFF were all measured. Variabilities of these functions and correlation between chromatic and luminance CFFs were also evaluated. For both the MS group and the normal control group, the correlations between pairs of visual parameters were not overall significantly greater than chance level. The MS group did give a significantly reduced value relative to the normal group for luminance CFF and for the gradient of the plot of chromatic CFF against luminance CFF. This group was then subdivided according to history of visual involvement. The subgroup with previous visual symptoms had significant impairment for luminance threshold, variability of luminance threshold, luminance CFF, variability of two-flash resolution, and for the gradient of the plot of chromatic CFF against luminance CFF. The subgroup without previous visual symptoms showed no significant impairment for any individual parameter, although the gradient of the plot of chromatic CFF against luminance CFF was lower than normal.

Induction of oviposition in cycling Anolis carolinensis requires a beta-adrenoreceptor blocker and a high dosage of arginine vasotocin

In a previous study, a high dosage (2.0 micrograms) of arginine vasotocin (AVT), following 10 micrograms of dichloroisoproterenol, induced oviposition in Anolis carolinensis at the end of the breeding season. The present study determined if a lower dosage of AVT (0.25 microgram), comparable to that effective in other lizard species, would induce oviposition in cycling A. carolinensis. Only a high dosage of AVT (2.0 micrograms), following 10 micrograms of dichloroisoproterenol 15 min beforehand, induced oviposition. These results suggest that uterine smooth muscle of A. carolinensis is relatively insensitive to AVT.