Pineal-gonadal relationship in the teleost Channa punctatus (Bloch): evidence for possible involvement of hypothalamic serotonergic system

In Channa punctatus, pinealectomy results in an accelerated growth (stimulatory effect) of the ovary in preparatory phase (March), but had no significant effect in prespawning (May-June) or postspawning (September) phases. Administration of melatonin (25 micrograms/fish or 0.4 mg/kg BW at 2-day intervals for 30 days) inhibits the stimulatory effect of a long photoperiod and high temperature (16L:8D; 22 +/- 1 degree C) on the ovary in the early preparatory phase (February). In the late preparatory phase (April), the administration of both melatonin (0.5 mg/kg BW at 2-day intervals) and parachlorophenylalanine (pCPA, a serotonin synthesis blocker; 100 mg/kg BW at 3-day intervals) for 30 days inhibits ovarian activity in comparison to that of the saline-treated control group. In the dose-response study, greater than or equal to 0.5 mg/kg BW of melatonin induced a significant increase in hypothalamic 5-HT content and greater than or equal to 10 mg/kg BW of pCPA decreased it significantly. In the time-course study, melatonin (2.0 mg/kg BW) elevates the 5-HT content significantly after an hr of the injection and maintained it up to 48 hrs. The administration of pCPA (200 mg/kg BW) had significantly inhibited the 5-HT content which was sustained for 72 hr. In another study, a single injection of melatonin (0.5 mg/kg BW) increased the 5-HT content significantly. A single injection of pCPA (100 mg/kg BW) decreased significantly both the content and activity of 5-HT. It is inferred that hypothalamic 5-HT may play a central role in photosexual mechanisms and mediate long photoperiodic effects on neuroendocrine-reproductive axis.

Changes in hypothalamic monoamine oxidase activity in relation to 17 beta-estradiol and clomiphene citrate treatments in the teleost Channa punctatus during three seasons

Hypothalamic monoamine oxidase (MAO) activity displayed biphasic responses to administration of estradiol-17 beta (E2) depending on season. Lower doses of 0.05 and 0.10 microgram/g BW of E2 had enhanced enzyme activity and higher doses (0.5 and 1.0 microgram/g BW) depressed it significantly in preparatory season. In prespawning phase, the lowest dose of 0.05 microgram/g BW of E2 was stimulatory and the higher doses were inhibitory to MAO activity. In postspawning season, lower doses (0.05 and 0.10 microgram/g BW) of E2 failed to elicit any significant change in enzyme activity whereas the higher doses (0.5 and 1.0 microgram/g BW) elevated it significantly. Administration of clomid (5, 10, and 20 micrograms/g BW) inhibited MAO activity in a dose-dependent manner during all the three seasons. The results show that E2 may participate in feedback control of gonadotropin secretion by modifying monoaminergic activity at the level of oxidative deamination by MAO.

Selective osmotic effect on diffusion of plasma membrane lipids in maize protoplasts

Osmotic levels in the range typically used during plant protoplast isolation and incubation were investigated with regard to effects on the lateral diffusion of lipid probes in the plasma membrane. The lateral diffusion coefficient of a fluorescent sterol probe in the plasma membrane of maize (Zea mays L.) root protoplasts in a medium containing 0.45 M mannitol was 4 times faster than when the medium contained 0.9 M mannitol. The lateral diffusion coefficient of a fluorescent phospholipid probe, however, did not change over this range of mannitol concentrations. Similar diffusion characteristics were observed when the medium contained trehalose instead of mannitol. Slower lateral diffusion of the sterol probe at higher osmolality was also observed when KCl/CaCl2-based osmotic media were used with protoplasts isolated by a mechanical, rather than by an enzymic, method. Extraction and quantitation of total lipids from protoplasts showed that both the phospholipid and sterol contents per protoplast decreased with increasing osmolality, while the sterol/phospholipid ratio increased. These results demonstrate that osmotic stress induces selective changes in both the composition and biophysical properties of plant membranes.

Prevalence of cryptosporidium in Rawalpindi/Islamabad a comparison of saline, iodine and stained preparations

Three hundred stool samples for routine ova and parasite examination were examined as saline and iodine wet preparations, the results were then compared with the Zeihl-Neelsen-modified Acid Fast staining (MAFS), as the oocysts are acid fast in character. Examination with saline preparation was unable to detect any oocyst, while iodine preparation yielded three oocyst and stained smears with MAFS revealed five positive stool samples.

Differential effects of photoperiod and temperature on hypothalamic monoaminergic activity in the teleost Channa punctatus (Bloch)

In Channa punctatus maintained under ambient photothermal conditions (10.5L:13.5D; 13 ± 2°C) in the postspawning season, hypothalamic dopamine (DA) and norepinephrine (NE) content varied diurnally, but serotonin (5-HT) and monoamine oxidase (MAO) did not. Exposure of the fish to high temperature (25 ± 2°C), with or without altering the photopheriod, increased the NE and DA content, and NE turnover but decreased DA turnover. Increasing the photoperiod (16L:8D) alone had no significant effect on catecholaminergic (CA) content or activity. When the fish were exposed to long photoperiod, with or without altering the temperature, a day-night variation in 5-HT content and activity was induced in the postspawning season. An increase in temperature alone had no significant effect on 5-HT content or activity. Hypothalamic MAO activity was elevated in fish exposed to high temperature alone, or in combination with long photoperiod, but was not affected significantly by long photoperiod treatment. These results indicate that CA activity is influenced largely by ambient high temperature, whereas serotonergic activity is controlled primarily by photoperiod, with high temperature having an additive effect. MAO activity seems to be influenced by both temperature and photoperiod in this species.

Induction of antigen-specific human cytotoxic T cells by Toxoplasma gondii

To further the understanding of the role of T cells in immunity to the parasite Toxoplasma gondii, antigen-specific T cell clones were generated using peripheral blood mononuclear cells from seropositive individuals. Whole parasites were used to stimulate a proliferative expansion of antigen-reactive cells, followed by limiting dilution cloning in the presence of irradiated, autologous PBMC and rIL-2. Three parasite antigen-specific T cell clones expressing the CD3+ phenotype were selected for further characterization. Phenotypic analysis with monoclonal antibodies revealed two clones reactive with CD8 (RTg1 and RTg3) while the other (RTg2) phenotyped as CD4+, CD8-. When tested in a proliferation assay using a panel of different T. gondii proteins, clone RTg1 reacted with a single large protein (Mr greater than 180,000) as well as smaller components (less than 12,000), clone RTg2 reacted with a protein of Mr = 28,000 and clone RTg3 reacted with a protein of 116,000 plus smaller components (less than 12,000). Only the 28,000 = Mr antigen recognized by RTg2 was reactive on Western blot with autologous donor antisera. All three clones produced IFN-gamma and IL-2 in varying amounts upon antigenic stimulation in the presence of irradiated APC. Moreover, one clone RTg1, exhibited direct parasite cytotoxicity, inhibiting extracellular T. gondii by greater than 70% when incubated at an effector/target ratio of 40:1. This clone was alpha, beta TCR heterodimer positive and exerted its cytotoxic parasiticidal activity in the apparent absence of MHC restriction. The results provide evidence for the existence of circulating antigen-specific cytotoxic T cells in normal humans who are toxoplasma antibody seropositive.

Effects of season, pinealectomy, and blinding, alone and in combination, on hypothalamic monoaminergic activity in the teleost Channa punctatus (Bloch)

In Channa punctatus, day-night variations in hypothalamic 5-HT (serotonin) and monoamine oxidase (MAO) activity were noticed in preparatory but not other phases (prespawning and postspawning) of the annual reproductive cycle. Hypothalamic MAO, 5-HT, and norepinephrine (NE) activity was found to be high in the prespawning phase and low in the postspawning phase. Dopamine (DA) activity, on the other hand, was high in the postspawning season and low in the prespawning phase. Pinealectomy caused season-dependent effects on hypothalamic monoaminergic activity, with a significant increase in serotonergic activity and a significant reduction in MAO activity at midscotophase during the preparatory phase (March) but not in the prespawning (May-June) or postspawning (September) phases. Hypothalamic catecholaminergic (CA) activity was not influenced by pinealectomy during any of the seasons. To determine whether or not the photoperiodic influences on daily variations of 5-HT and MAO in the preparatory phase are mediated via pineal and/or lateral eyes, fish were pinealectomized and/or blinded in January, when there is no rhythm, and sacrificed in February, when a day-night variation normally sets in. The day-night difference in 5-HT content and activity and MAO activity was not abolished by pinealectomy or blinding alone; but the combination (pinealectomy + blinding) obliterated the daily variation only in 5-HT content and in MAO activity. However, pinealectomy and blinding, alone or in combination, caused a significant elevation of 5-HT activity (not its level) and a significant decrease in MAO activity at midscotophase, with the combination having an additive effect. Hypothalamic CA content or activity was not affected by these regimes. The results show that photoperiodic influence on the daily pattern of 5-HT and MAO activity is mediated through and by the interaction of the pineal and lateral eyes.

Lateral diffusion in the plasma membrane of maize protoplasts with implications for cell culture

Plasma-membrane dynamics in live protoplasts from maize (Zea mays L.) roots were characterized and examined for relationships as to the ability of the protoplasts to synthesize new cell walls and develop to cells capable of division. The lateral diffusion-coefficients and mobile fractions of fluorescence-labeled plasma-membrane proteins and lipids were measured by fluorescence photobleaching recovery. Small but significant effects on the diffusion of membrane proteins were observed after treatments with oryzalin or amiprophosmethyl, microtubule-disrupting drugs that increased the mobile fraction, and after treatments with cytochalasins B or D, microfilament-disrupting drugs that decreased the diffusion coefficient. A number of parameters were tested for correlative effects on membrane dynamics and protoplast performance in culture. Protoplasts isolated with a cellulase preparation from Trichoderma viride showed faster membrane-protein diffusion and a lower frequency of development to cells capable of division than did protoplasts isolated with a cellulase preparation from T. reesei. Membrane proteins in maize A632, a line less capable of plant regeneration from callus, diffused with a smaller diffusion coefficient but a greater mobile fraction than did membrane proteins in maize A634, a line with greater regeneration capacity. The plasma membranes of A632 and A634 protoplasts also differed with regard to lateral-diffusion characteristics of phospholipid and sterol probes, although the presence of both rapidly and slowly diffusing lipid components indicated the apparent existence of lipid domains in both A632 and A634. The protoplasts of the two lines did not differ significantly, however, in either wall regeneration or frequency of development to cells capable of division.

Therapeutic and injurious characteristics of thermal and sulphurous springs

The dissolution of underground rocks by water, flowing underneath, makes the water rich with chemical compounds and ions. These chemical constituents with the heat of water, absorbed from the exothermic reactions of volcanic activities, gain the therapeutic properties to human sufferings or vice versa. The general history of sulphurous and thermal springs, their effects and causes are discussed below.

Induction of antigen-specific parasiticidal cytotoxic T cell splenocytes by a major membrane protein (P30) of Toxoplasma gondii

Infection with Toxoplasma gondii has become a major cause of morbidity in patients with AIDS. To investigate the mechanisms responsible for immune responses to toxoplasma Ag we used a highly purified membrane protein (P30) of T. gondii to stimulate an in vitro Ag-specific cytotoxic T cell response. P30 immune mouse splenocytes reduced extracellular T. gondii plaque-forming units by more than 50% when incubated at an E/T ratio of 10:1 or greater. By using a [3H]uracil radioisotope release assay, the effect of the immune splenocytes was determined to be a direct parasite lytic mechanism. The immune splenocytes were P30 Ag specific and of the Thy 1.2, Lyt2,3+ (CD4-, CD8+) phenotype, specific for mouse cytotoxic T cells. Opsonization of the parasites with monoclonal P30-reactive mAb did not enhance parasiticidal activity. Culture supernatants obtained during the 2-h cytotoxic assay were not parasiticidal, and anti-asialo-GM1 antibody plus C did not destroy the parasiticidal activity of the P30 responder cells. Accordingly, we have identified an Ag-specific subset of CD4-, CD8+, P30 responder T cells that are directly parasiticidal to extracellular T. gondii, and that exhibit cytotoxicity independent of antibody opsonization, lymphokine secretion, NK cell activity, and, apparently, MHC involvement as well.

Induction of antigen-specific parasiticidal cytotoxic T cell splenocytes by a major membrane protein (P30) of Toxoplasma gondii

Infection with Toxoplasma gondii has become a major cause of morbidity in patients with AIDS. To investigate the mechanisms responsible for immune responses to toxoplasma Ag we used a highly purified membrane protein (P30) of T. gondii to stimulate an in vitro Ag-specific cytotoxic T cell response. P30 immune mouse splenocytes reduced extracellular T. gondii plaque-forming units by more than 50% when incubated at an E/T ratio of 10:1 or greater. By using a [3H]uracil radioisotope release assay, the effect of the immune splenocytes was determined to be a direct parasite lytic mechanism. The immune splenocytes were P30 Ag specific and of the Thy 1.2, Lyt2,3+ (CD4-, CD8+) phenotype, specific for mouse cytotoxic T cells. Opsonization of the parasites with monoclonal P30-reactive mAb did not enhance parasiticidal activity. Culture supernatants obtained during the 2-h cytotoxic assay were not parasiticidal, and anti-asialo-GM1 antibody plus C did not destroy the parasiticidal activity of the P30 responder cells. Accordingly, we have identified an Ag-specific subset of CD4-, CD8+, P30 responder T cells that are directly parasiticidal to extracellular T. gondii, and that exhibit cytotoxicity independent of antibody opsonization, lymphokine secretion, NK cell activity, and, apparently, MHC involvement as well.

TLC and HPLC analysis of Echinacea pallida and E. angustifolia roots

The roots of ECHINACEA PALLIDA are characterized by TLC and HPLC fingerprints of the polyacetylenes, polyenes, and the caffeic acid derivatives. The fingerprints can also be used for the differentiation between E. PALLIDA and E. ANGUSTIFOLIA root extracts. The main constituents of E. PALLIDA roots are tetradeca-8 Z-ene-11,13-diyn-2-one ( 2), pentadeca-8 Z-ene-11,13-diyn-2-one ( 3), pentadeca-8 Z,13 Z-dien-11-yn-2-one ( 4), pentadeca-8 Z,11 Z,13 E-trien-2-one ( 5), pentadeca-8 Z,11 E,13 Z-trien-2-one ( 6), pentadeca-8 Z,11 Z-dien-2-one ( 7), and echinacoside ( 13). E. ANGUSTIFOLIA is usually void of these polyacetylenes and polyenes and is characterized by isobutylamides, echinacoside, and cynarine. The polyacetylenes of E. PALLIDA are very susceptible to autoxidation to the 8-hydroxy-9-ene derivatives. Thus, the chemical composition of the roots depends on the storage conditions.

Diurnal variations in hypothalamic monoamine levels in the teleostChanna punctatus (bloch) in response to melatonin under two photothermal conditions

Hypothalamic dopamine (DA), noradrenaline (NA) and 5-hydroxytryptamine (5-HT) levels exhibited marked day-night variations under ambient photoperiod and temperature (12L∶12D; 17±1°C) with peak values at mid-light phase. The 16L∶8D; 22±1°C treatment reversed the diurnal rhythm of 5-HT, but not that of DA and NA. However, there was an overall increase in the levels of the catecholamines on exposure to the long photoperiod and high temperature. The administration of melatonin in the fish held on 16L∶8D; 22±1°C regime restored the 5-HT rhythm to that of the 12L∶12D; 17±1°C control group, but with elevated mid-photophase value. However, there was no effect of the indole treatment on the 5-HT rhythm under the 12L∶12D; 17±1°C regime. Melatonin causes a significant reduction of NA level in both the groups, while DA level did not change in either group.

Production of gamma interferon by cultured human lymphocytes stimulated with a purified membrane protein (P30) from Toxoplasma gondii

Purified P30, the principal iodinatable membrane protein of Toxoplasma gondii, induced proliferation of peripheral blood mononuclear cells from seropositive individuals but not from seronegative individuals. Culture supernatants from stimulated cells of seropositive individuals blocked the growth of T. gondii in human fibroblasts, whereas those from antibody-negative individuals failed to do so. The anti-toxoplasmic effect of culture supernatants correlated with the induction of indoleamine 2,3-dioxygenase and the destruction of tryptophan, as previously described for fibroblasts treated with recombinant gamma interferon (IFN-gamma). The anti-toxoplasmic effect was blocked by monoclonal antibody to IFN-gamma. The protective effect correlated with the amount of IFN-gamma in the culture supernatant, as measured by inhibition of viral CPE. Thus, the level of IFN-gamma appears to be an important immune factor in protection against toxoplasmosis in humans.

Native-like intermediate on the folding pathway of Escherichia coli succinyl-CoA synthetase

The transition between the native and denatured states of the tetrameric succinyl-CoA synthetase from Escherichia coli has been investigated by circular dichroism, fluorescence spectroscopy, cross-linking by glutaraldehyde and activity measurements. At pH 7.4 and 25 degrees C, both denaturation of succinyl-CoA synthetase by guanidine hydrochloride and refolding of the denatured enzyme have been characterized as reversible reactions. In the presence of its substrate ATP, the denatured enzyme could be successfully reconstituted into the active enzyme with a yield of 71-100%. Kinetically, reacquisition of secondary structure by the denatured enzyme was rapid and occurred within 1 min after refolding was initiated. On the other hand, its reactivation was a slow process which continued up to 25 min before 90% of the native activity could be restored. Both secondary and quaternary structures of the enzyme, reconstituted in the absence of ATP, were indistinguishable from those of the native enzyme but the renatured protein was catalytically inactive. This observation indicates the presence of catalytically inactive tetramer as an intermediate in the reconstitution process. The reconstituted protein could be reactivated by ATP even 10 min after the reacquisition of the native secondary structure by the refolding protein. However, reactivation of the protein by ATP 60 min after the regain of secondary structure was significantly less, suggesting that rapid refolding and reassociation of the monomers into a native-like tetramer and reactivation of the tetramer are sequential events; the latter involving slow and small conformational rearrangements in the refolded enzyme that are likely to be associated with phosphorylation.

Seasonal and daily variations in hypothalamic monoamine levels and monoamine oxidase activity in the teleost Channa punctatus (Bloch)

In Channa punctatus, a significant daily variation in hypothalamic 5-HT level and monoamine oxidase (MAO) activity was noticed in preparatory phase (February), but not in prespawning (May) or postspawning (November) phases. Hypothalamic dopamine (DA) and noradrenaline (NA), on the other hand, showed marked daily variation in their levels during all the three seasons with peak values in the photophase. The overall activity of MAO (mean +/- SEM on 24-hr period) increased from November to May through February, whereas the 5-HT content which was high in November decreased during February and May. The NA and DA levels were low in November and February and high in May. The catecholamine (CA) content and MAO activity increased with increasing photoperiod and temperature which is indicative of an enhanced CA metabolism.

Induction of spermatogenesis and spermiation by a single injection of human chorionic gonadotropin in intact and hypophysectomized immature European eel (Anguilla anguilla L.)

Intact and hypophysectomized male silver eels (Anguilla anguilla) in fresh water received a single injection of human chorionic gonadotropin (hCG) (250 C) or solvent (0.15 M NaCl). No effect of solvent was observed. Spermatogonia proliferated in testis of hCG-treated intact or hypophysectomized eels. One month after the injection, primary and secondary spermatocytes were found. After 3 months, numerous spermatozoa were present. In hypophysectomized eels, hCG was also effective even though maturing germ cells were less numerous and spermiation was less frequent than in intact animals. Within 1 week after hCG injection, plasma levels of free and glucuroconjugated androgens (testosterone and 11-oxotestosterone) rose significantly in intact and hypophysectomized fish. The highest values were observed within 1 month, and then plasma levels decreased to pretreatment values. The most important changes were observed in the case of free 11-oxotestosterone. The long-term effects of hCG can be explained partly by the long half-life of this hormone. The effects of hypophysectomy on the response of testis to hCG caused us to think that some endogenous pituitary secretions must interfere in the intact fish so that maximal effects of hCG, especially on the induction of spermiation, are obtained.

Prognostic indices of typhoid perforation

Fifty-eight cases of typhoid perforation are presented. Each case was treated surgically, and the causes of the high post-operative mortality rate are discussed. In this series of patients, the chances of survival after typhoid perforation seem to depend on the following factors: Fever: There is a significantly better prognosis if the perforation occurs in the first week of fever. Period before surgical treatment: The longer the time interval between perforation and surgery, the worse is the prognosis. Serology: Patients giving a negative Widal result and showing a high 'H' antigen titre are more likely to survive. Size of perforation: A patient who has a perforation larger than 10 mm in diameter appears to have a poor chance of survival, but this is not statistically significant. Type of surgery: Resection of the ileum with end to end anastomosis apparently gives the best prognosis, and simple closure of the perforation seems the next best. Drainage of the peritoneum and ileostomy appear mainly ineffective, but these were only carried out in severe cases.