Dietary (n-3) polyunsaturated fatty acids exert antihypertensive effects by modulating calcium signaling in T cells of rats

After 10 wk of feeding an experimental diet enriched with (n-3) polyunsaturated fatty acids (PUFA), i.e., eicosapentaenoic acid [EPA, 20:5(n-3)] and [DHA, 22:6(n-3)] (EPAX), blood pressure in spontaneously hypertensive rats (SHR), but not in normotensive Wistar-Kyoto (WKY) rats was reduced relative to rats fed an unsupplemented control diet. Concanavalin A-stimulated T-cell proliferation was diminished in both strains of rats fed the PUFA/EPAX diet. The experimental diet lowered secretion of interleukin-2 in SHR, but not in WKY rats compared with rats fed the control diet. To determine whether there was a defect in calcium homeostasis in T cells during hypertension, we employed the following agents: caffeine, which recruits calcium from the cytosolic Ca(2+)-induced Ca(2+)-release pool; ionomycin, which at low concentrations opens calcium channels; and thapsigargin (TG), which mobilizes [Ca(2+)]i from the endoplasmic reticulum (ER) pool. Caffeine-induced increases in [Ca(2+)]i were not modified by the PUFA/EPAX diet. The ionomycin-induced increases in [Ca(2+)]i in T cells from SHR were greater than in those from WKY rats; consumption of the PUFA/EPAX diet did not modify Ca(2+) influx in cells of either strain. The TG-induced increases in [Ca(2+)]i in T cells from SHR were greater than those in cells from WKY rats. Interestingly, consumption of the experimental diet reduced TG-evoked increases in [Ca(2+)]i in T cells from SHR and increased those in T cells from WKY rats, indicating that the PUFA/EPAX diet could reverse the calcium mobilization from the ER pool in T cells. These results suggest that (n-3) PUFA exert antihypertensive effects and modulate T-cell calcium signaling during hypertension in rats.

Docosahexaenoic acid modulates phorbol ester-induced activation of extracellular signal-regulated kinases 1 and 2 in NIH/3T3 cells

Phosphorylation of extracellular signal-regulated kinases (ERK1/ERK2) has been implicated in cell proliferation of mammalian cells. In the present study, we investigated the role of docosahexaenoic acid (DHA) in the modulation of ERK1/ERK2 phosphorylation, stimulated either with phorbol 12-myristate 13-acetate (PMA) or transforming growth factor-alpha (TGFalpha) in NIH/3T3 cells. We observed that both PMA and TGFalpha induced ERK1/ERK2 phosphorylation within 5 min of stimulation. PMA acts upstream of MEK and via activation of protein kinase C (PKC), as GF109203X, a potent PKC inhibitor, and U0126, a MEK inhibitor, abolished its actions on ERK1/ERK2 phosphorylation. TGFalpha did not act via PKC because GF109203X failed to curtail the degree of ERK1/ERK2 phosphorylation in these cells. DHA alone failed to induce the phosphorylation of these mitogen-activated protein (MAP) kinases; however, this fatty acid significantly curtailed the PMA- but not TGFalpha-induced MAP kinase enzyme activity and phosphorylation in NIH/3T3 cells. Furthermore, we observed that DHA significantly inhibited PMA-induced translocation of two PKC isoforms, PKC alpha and PKC epsilon, from cytosol to plasma membrane. Interestingly, DHA failed to inhibit the PMA-induced translocation PKC delta isoform in these cells. Furthermore, DHA decreased PMA-induced proliferation of NIH/3T3 cells. In this study, we show for the first time that DHA inhibits MAP kinase ERK1/ERK2) activation and proliferation of NIH/3T3 cells via its inhibitory action on PKC alpha and epsilon isoforms.

Yield and costs of screening growth-retarded infants for torch infections

Many infants with intrauterine growth retardation (IUGR) are screened for TORCH infections. The yield and costs of such a practice may not be justifiable. Medical charts of infants with IUGR who had a workup for toxoplasmosis, other (infections), rubella, cytomegalovirus (infection), and herpes (simplex) (titer) (TORCH) infections were reviewed for the presence of clinical findings, laboratory and head ultrasound abnormalities associated with intrauterine infections. Maternal charts and reports of placental pathology were reviewed for identifying maternal illnesses and placental causes associated with IUGR. Seventy-five out of 182 infants (41%) with IUGR had a workup for TORCH infection. Maternal conditions associated with IUGR included: pregnancy-induced hypertension (19%), tobacco use (43%), alcohol abuse (21%), illicit drug use (24%), chronic hypertension, diabetic vasculopathy or collagen vascular disease (12%), and multiple gestation (3%). Placental pathology was available in 53/75 cases. Thirty-six of fifty-three (67%) placentae had abnormalities associated with IUGR: placental infarcts (22 of 36), vasculitis/villitis (15 of 36), placenta previa (1 of 36), abruptio placenta (2 of 36), and velamentous insertion of umbilical cord (1 of 36). Clinical findings among infants included hepatosplenomegaly, cataract or rash (1 of 75), thrombocytopenia and/or neutropenia and/or direct hyperbilirubinemia (11 of 75). Seven out of 75 infants had dysmorphic features. None of the infants (0 of 75) had positive IgM titers for toxoplasma, rubella, cytomegalovirus (CMV), or herpes simplex virus (HSV). No infants (0 of 43) had elevated total IgM titers; one infant (1 of 57) had a positive urine culture for CMV. One infant had evidence of calcifications on head ultrasound and a second infant had hydrocephalus (2 of 43). The costs associated with workup for TORCH infections among 75 infants included: TORCH titers determination: $17,816, total IgM titers: $1318, urine culture for CMV: $5734, and head ultrasound: $28,165. The yield of workup for TORCH infection among infants with IUGR is poor and does not justify the incurred costs.

Proteases as markers for differentiation of pathogenic and nonpathogenic species of Acanthamoeba

Acanthamoeba keratitis is a vision-threatening infection caused by pathogenic species of the genus Acanthamoeba. Although not all Acanthamoeba spp. can cause keratitis, it is important to differentiate pathogenic species and isolates from nonpathogens. Since extracellular proteases may play a role in ocular pathology, we used colorimetric, cytopathic, and zymographic assays to assess extracellular protease activity in pathogenic and nonpathogenic Acanthamoeba. Colorimetric assays, using azo-linked protein as a substrate, showed extracellular protease activity in Acanthamoeba-conditioned medium and differentiated pathogenic and nonpathogenic Acanthamoeba. Monolayers of immortalized corneal epithelial cells in four-well plates were used for cytopathic effect (CPE) assays. Pathogenic Acanthamoeba isolates exhibited marked CPE on immortalized corneal epithelial cells, while nonpathogenic isolates did not exhibit CPE. Protease zymography was performed with Acanthamoeba-conditioned medium as well as with Acanthamoeba- plus epithelial-cell-conditioned medium. The zymographic protease assays showed various banding patterns for different strains of Acanthamoeba. In pathogenic Acanthamoeba isolates, all protease bands were inhibited by phenylmethylsulfonyl fluoride (PMSF), suggesting serine type proteases, while in nonpathogenic strains only partial inhibition was observed by using PMSF. The pathogenic Acanthamoeba strains grown under typical laboratory conditions without epithelial cells exhibited one overexpressed protease band of 107 kDa in common; this protease was not observed in nonpathogenic Acanthamoeba strains. The 107-kDa protease exhibited activity over a pH range of 5 to 9.5.

Isolation of Acanthamoeba-specific antibodies from a bacteriophage display library

Acanthamoeba causes opportunistic eye infections in humans, which can lead to severe keratitis and may ultimately result in blindness. Current methods for identifying this organism rely on culture and microscopy. In this paper, we describe the isolation of antibody fragments that can be used for the unequivocal identification of Acanthamoeba. A bacteriophage antibody display library was used to isolate antibody fragments that bind specifically to Acanthamoeba. Individual clones were studied by enzyme-linked immunosorbent assay, flow cytometry, and immunofluorescence. Four antibody clones that specifically bind to Acanthamoeba spp. were identified.

Influence of nitric oxide synthase II gene disruption on tumor growth and metastasis

The relationship between nitric oxide (NO) synthase II (NOS II) expression and the metastatic ability of tumor cells is inconclusive. We determined the role of host NOS II expression in the growth and metastasis of the B16-BL6 murine melanoma and M5076 murine ovarian sarcoma cell lines. The cells were either s.c. or i.v. injected into syngeneic wild-type (NOS H+/+) and NOS II-null (NOS H-/-) C57BL/6 mice. Both cell lines produced slightly larger s.c. tumors in NOS H-/- mice than in NOS II+/+ mice. However, B16- BL6 cells produced more and larger experimental lung metastases in NOS II+/+ mice than in NOS II-/- mice, whereas M5076 cells produced fewer and smaller experimental lung metastases in NOS II+/+ mice than in NOS II-/- mice. After activation with IFN-gamma and lipopolysaccharide, macrophages isolated from NOS II+/+ C57BL/6 mice produced NO-dependent cytotoxicity in sarcoma cells, whereas macrophages from NOS II-/- C57BL/6 mice did not. In contrast, activated macrophages produced little to no NO-mediated cytotoxicity in melanoma cells. Immunostaining analyses indicated that NOS II expression was apparent in the metastases growing in NOS H+/+ mice and correlated with increased cell proliferation in B16-BL6 lung metastases but with decreased cell proliferation in M5076 liver metastases. Our data suggest that disruption of host NOS II expression enhanced the growth and metastasis of NO-sensitive tumor cells but suppressed the metastasis of NO-resistant tumor cells, proposing that host-derived NO may differentially modulate tumor progression.

Regulation of calcium signalling by docosahexaenoic acid in human T-cells. Implication of CRAC channels

We elucidated the role of docosahexaenoic acid (DHA) on the increases in free intracellular calcium concentrations, [Ca(2+)]i, in human (Jurkat) T-cell lines. DHA evoked an increase in [Ca(2+)]i in a dose-dependent manner in these cells. Anti-CD3 antibody, known to stimulate increases in Ca(2+) from endoplasmic reticulum (ER) via the production of inositol trisphosphate, also evoked increases in [Ca(2+)]i in Jurkat T-cells. We also used thapsigargin which inhibits Ca(2+)-ATPase of the ER and, therefore, increases Ca(2+) in the cytosol. Interestingly, addition of DHA during the thapsigargin-induced peak response exerted an additive effect on the increases in [Ca(2+)]i in human T-cells, indicating that the mechanisms of action of these two agents are different. However, the DHA-induced calcium response was not observed when this agent was added during the anti-CD3-induced calcium peak, though its addition resulted in a prolonged and sustained calcium response as a function of time, suggesting that DHA recruits calcium, in part, from the ER pool and the prolonged response may be due to Ca(2+) influx. In the medium containing 0% Ca(2+), the DHA-evoked response on the increases in [Ca(2+)]i was significantly curtailed as compared to that in 100% Ca(2+) medium, supporting the notion that the response of the DHA is also due, in part, to the opening of calcium channels. Furthermore, preincubation of cells with tyrphostin A9, an inhibitor of Ca(2+) release-activated Ca(2+) (CRAC) channels also significantly curtailed the DHA-induced sustained response on the increases in [Ca(2+)]i in these cells. These results suggest that DHA induces an increase in [Ca(2+)]i via the ER pool and the opening of CRAC channels in human T-cells.

Use of unconventional methods of therapy by cancer patients in Pakistan

Most of the studies related to the use of unconventional methods of therapy by cancer patients have been carried out in the developed countries. This study was conducted to ascertain the frequency, type, and duration of use of unconventional methods of therapy by cancer patients in Pakistan. We also wanted to identify individuals who are most likely to use these methods and to compare the findings with those reported from the developed countries. Between 1 April and 30 May 1994, all patients with histologically proven cancer who visited the oncology unit were interviewed. A printed questionnaire with questions and options was used as an interview guide. Informed consent was obtained. One hundred and ninety-one patients were interviewed, on average, for 25 minutes each. Use of unconventional methods of therapy by cancer patients was widespread (54.5% of all patients). The majority (83.7%) were influenced by family members to use these methods. Traditional herbal medicines (70.2%) and homeopathy (64.4%) were the most commonly employed methods. Thirty-six percent of the users employed these methods before receiving any conventional therapy. Only 15% used these methods after conventional therapeutic options had been exhausted. Patients generally perceived these methods as useful, non-toxic and inexpensive. Age, marital status, socio-economic background, education level and status of underlying neoplasm did not influence the frequency of use of unconventional methods. The use, however, was influenced by gender, family size, and type of underlying malignancy. Patients aware of their diagnosis were less likely to use these methods. This study suggests that use of unconventional methods by cancer patients in Pakistan is widespread. Unlike western countries, these methods are often employed before receiving any conventional therapy. This probably results in a significant delay which can be expected to adversely influence the subsequent disease management and survival. Public education, reduction of cost and easy availability of conventional therapy may be helpful in reducing the use of methods which otherwise may have no proven value.

Methemoglobinemia induced by topical anesthesia: a case report and review

Topical anesthetic drugs are widely used by clinicians during hospital and outpatient procedures and are also available to the public in a variety of over-the-counter preparations. Although generally safe, they may cause potentially life-threatening methemoglobinemia. We describe a patient who developed repeated episodes of severe methemoglobinemia after administration of topical Cetacaine spray (a proprietary mixture of benzocaine, tetracaine, and butamben) employed for pharyngeal anesthesia before endotracheal intubation, and briefly review the etiology and pathophysiology of this disorder. Cautious interpretation of oxyhemoglobin saturation values obtained by pulse oximetry or estimated from arterial blood gas analysis is crucial lest the diagnosis of severe methemoglobinemia and the resulting hypoxemia are overlooked. If necessary, the condition is usually readily corrected by intravenous administration of methylene blue.

Ionotrophic 5-hydroxytryptamine type 3 receptor activates the protein kinase C-dependent phospholipase D pathway in human T-cells

The present study was undertaken to investigate the role of the 5-hydroxytryptamine (5-HT) ionotrophic receptor 5-HT(3) in the activation of human Jurkat T-cells. 5-HT and 2-methyl-5-HT (2Me-5-HT), an agonist of the 5-HT(3) receptor, induced increases in intracellular free Na(+) concentrations, [Na(+)](i), via opening of the ionotrophic receptor in these cells. These two serotonergic (5-hydroxytryptaminergic) agents potentiated phytohaemagglutinin (PHA)-induced T-cell activation. However, they failed to potentiate dioctanoglycerol-plus-ionomycin-stimulated T-cell blastogenesis. Interestingly, an inhibitor of protein kinase C (PKC), GF 109203X, curtailed significantly 5-HT and 2Me-5-HT-potentiated T-cell activation. These results demonstrate that the opening of the 5-HT(3) ionotrophic receptor is implicated in T-cell activation via the PKC pathway. Furthermore, 5-HT and 2Me-5-HT stimulated phospholipase D (PLD) activity, as measured by the production of phosphatidylethanol and phosphatidylbutanol at the expense of phosphatidic acid (PA). GF 109203X significantly curtailed the 5-HT- and 2Me-5-HT-induced PLD activity and T-cell activation. The PLD/PA pathway stimulated by these two serotonergic agents resulted in the production of 1,2-diacylglycerol (DAG) mass in Jurkat T-cells. These results altogether suggest that 5-HT and 2Me-5-HT potentiate T-cell activation via increases in [Na(+)](i) and the activation of the PKC-dependent PLD pathway.

5-HT3 receptor-channels coupled with Na+ influx in human T cells: role in T cell activation

The study was conducted on a human (Jurkat) T cell line, loaded with a Na+ fluorescent probe, SBFI/AM. Serotonin and an agonist of 5-HT3 receptor-channels, 2-methyl-5HT, evoked Na+ influx, whereas the agonists of other serotonergic receptor subtypes, i.e., 5-HT1A and 5-HT1B receptors, failed to induce Na+ influx in these cells. By using 3H-BRL43694, an agonist of 5-HT3 receptor-channels, we characterized 5-HT3 lymphocyte receptors which exhibited a density (Bmax) of 300 +/- 20 fmol/10(6) cells and a Kd of 30 nM in Jurkat T cells. The T-cell 5-HT3 receptor-channel is not regulated either by the protein kinase C or by the free intracellular calcium concentrations as the agents known to activate the PKC and to induce increases in intracellular free calcium concentrations failed to influence the free intracellular Na+ concentrations, [Na+]i, in these cells. Furthermore, an increase in [Na+]i, induced by 2-methyl-5HT, via 5-HT3 receptor-channels seems to stimulate T-cell activation by facilitating the progression of T cells from S to G2/M phase of the cell cycle.

Characterisation of serotonin transport mechanisms in rainbow trout peripheral blood lymphocytes: role in PHA-induced lymphoproliferation

In this study, we investigated the serotonin transport mechanisms in rainbow trout (Oncorhynchus mykiss) peripheral blood Lymphocytes. We have observed that the transport of serotonin is a membrane transport process that have the properties of a secondary active transport system. The binding isotherm of [3H]-paroxetine, a serotonin transport blocker, demonstrated a high-affinity binding site with a positive type of cooperativity, Hill coefficient being higher than unity. Known specific inhibitors of the mammalian serotonin transporter significantly inhibited the uptake process in fish lymphocytes. In order to demonstrate the physiological relevance of the serotonin transporter in T-cell activation, we conducted experiments on lymphocytes activated or not by phytohemagglutinin (PHA), a T-cell mitogen. We have observed that addition of PHA for 24hrs, increased the Vmax but not the Km of this transporter. Serotonin uptake inhibitors diminished the PHA-activated proliferation of fish lymphocytes. The intracellular concentrations of cAMP were found to regulate the serotonin uptake and the PHA-stimulated proliferation as the agents known to augment cAMP stimulated serotonin uptake, and inhibited the lymphoproliferation. Inhibitory effects of increased cAMP on the proliferation were reversed by the addition of the nanomolar concentrations of 8-OH-DPAT, a 5-HT1A receptor agonist which is known to diminish the intracellular cAMP concentrations, suggesting that serotonin also regulates PHA-induced proliferation via 5-HT1A membrane receptors in an autocrine manner. These results all together demonstrate that fish lymphocytes possess an active serotonin transporter that is implicated in the proliferation of these immunocompetent cells.

Body mass index (BMI) in the Saudi population of Gassim

In a total cross-sectional population survey of the Faizia East Primary Health District of Buraidah, Gassim region of Saudi Arabia, 6,044 (2727 male and 3317 females) subjects out of a de facto population of 7695 got their BMI computed because infants and restless or bedridden subjects could not be examined. Mean (+/- SD) and percentiles (25th & 75th) were calculated in the conventional 5-year age cohorts as well as in functional age groups, namely, 0-5, 6-12, 13-49, 50-69 and 70+ years. 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles were computed only for the functional age groups. In general, the trend was for BMI to increase with age in both genders but the curve pattern showed some plateauing from about the age of 50 with slight decline in later life. Females had significantly higher indices than males, this becoming quite prominent from the 10-14 year age cohort. This difference persisted irrespective of the types of age grouping or residential location. Overall means (+/- SD) were 20.14 +/- 5.98 vs 22.22 +/- 7.21 for males and females respectively; df: 5771; p = 0.0000; 95% CI: -2.43, -1.735. Subjects in the urban living environment had significant higher indices than their rural counterpart: (21.666.92 vs 20.446.33: df: 5771; P = 0.0000; 95% CI: 1.595, -0.840). From the age of 15 about one quarter of females are overweight (BMI at the 75th percentile > 25) and from 30 years the same proportion are frankly obese (BMI > 30). Both systolic and diastolic blood pressure were significantly positively correlated with BMI in both genders: male SBP: r = 0.22, P < 0.0001; male DBP: r = 0.21, P < 0.00001; female DBP: r = 0.18, P < 0.00001.

Studies of preventive nephrology: self-urinalysis as a feasible method for early detection of renal damage

The ever expanding pool of ESRF patients is exerting considerable strain on the health care resources of all nations of the world. Rationing, in one form or the other has therefore become the norm for most countries. Because dialysis prolongs life and is more readily available, and because ethically acceptable donor kidneys remain in short supply, thus limiting the potential of renal transplantation, this rather exasperating situation is bound to continue unless the entry point into the pool can be actively tacked. As part of our initial effort in this direction, we have examined the feasibility of self urinalysis by the general population as an epidemiological tool for detecting evidence of early renal damage by a total population cross-sectional survey of Faizia East Primary Health District (FEPHD) of Buraidah, capital city of the Gassim region of Saudi Arabia. Out of a de facto population of 7,695, 75.37% (5,800) cooperated fully. Majority of those who could not cooperate (881 [11.44%]) were infants and children. A total of 969 subjects (12.59%), mostly males at work, were not available. Only 45 (0.58%) subjects refused to participate. Housewives were significantly more amenable to the organisation of family self-urinalysis than head of the family (92.2% vs 61.4%; chi square = 321.78; df: 3; P < 0.0001). The mean family size was 7.82 (+/- SD: 3.82). Above the age of 4 years, 66.5% of males (2108/3170) as against 81.7% of females (2,641/3232) were able to carry our self-urinalysis. 11.76% of boys and 8.5% of girls below the age of 5 years were able to carry out self-urinalysis. Only 0.05% of male subjects and 0.03% of females failed to interpret colour change for proteinuria correctly. Similar remarkable competence was demonstrated for glycosuria by the population. We conclude that self-urinalysis is quite feasible in the general population, even if illiterates, if young. It can form a sound foundation, if properly harnessed, for a renal registry.

Some aspects of the pattern of systemic hypertension in the adult population of Gassim, Saudi Arabia: age distribution of the subsets of hypertensives

As part of our studies in prevent nephrology, we have recorded causal blood pressure during a total population cross-sectional survey of the Faizia East Primary Health District of Buraidah (FEPHD), capital of Gassim region of Saudi Arabia. Out of 5671 subjects whose blood pressure could be recorded, 2222 were above 19 years of age and constituted our adult population. For this report, hypertension have been defined as equal to and greater than 140/90 mm Hg. Total hypertensive population had been divided into three subsets, based on this basic definition, namely combined systolic and diastlic hypertension (S/DHPN), isolated systolic hypertension (ISHPN) and isolated diastolic hypertension (IDHPN), a format which is not generally clear in previous studies on the subject. The overall prevalence of systemic hypertension was found to be 23.58%, which is lower than the figure of 36% for USA (pre-primary prevention intensive campaign). It is assumed that all the three subsets mentioned above have been used in calculating the latter. Although males tended to be more hypertensive than females (OR = 1.22; Chi Square = 3.89; P = 0.05; C.I.: 1.00 < OR < 1.49), the marginal difference (25.7% vs 22.10%) was largely due to the IDHPN subset (OR = 1.73; Chi Square = 4.48; P = 0.034; C.I.: 1.01 < OR < 2.96). In both the S/DHPN and ISHPN: statistical significance was not achieved. Significantly, ISHPN subset constituted the bulk--56.68%--of the hypertensive population while IDHPN constituted the least--11.64%. When analysed into 10-year-age cohorts, ISHPN showed the steepest rise in prevalence with age. Rather suprisingly, the IDHPN did not rise with advancing age while the S/DHPN slope was in between the two. We are unable to identify this pattern in our literature search on the subject. We cannot assess its significance by this study, but we wonder whether or not it carries any prognostic significance in terms of target organ damage. It is possible that this pattern may be peculiar to the sub-region but it certainly is not spurious and in our view deserves further scrutiny. We wish to suggest that clear definition of the three subsets of hypertensive population should be mandatory when defining prevalence. This may provide some further clues in the prognosis and pathogenesis of target organ damage.

Blood pressure pattern in Saudi population of Gassim

Blood pressure pattern for the Kingdom of Saudi Arabia has not been defined. In a total cross-sectional population survey of the Faizia East Primary Health District of Buraidah, capital of Gassim region, Saudi Arabia, 5671 subjects out of a de facto population of 7695 got their blood pressure recorded. The study district consisted of an urban section and a rural sector. Mean systolic and diastolic blood pressure were computed for the total population in conventional 5-year age cohorts as well as in an arbitrary functional age groups. The curve pattern and trends of the percentiles, were defined. Mean blood pressure (systolic and diastolic) was found to rise with age in both genders (male SBP: r = 0.66, P < 0.000001: female SBP: r = 0.58, P < 0.00001; male DBP: r = 0.53, P < 0.00001; female DBP: r = 0.45, P < 0.00001) and to correlate significantly with BMI. Both systolic and diastolic values were consistently higher in females than males. Overall means (+/- SD) were: for SBP, male 109.9 (+/- 21.57) vs female 114.33 (+/- 21.22) mm Hg; df: 5669: P < 0.00000; CI: -5.5, -2.0; for DBP, male 62.85 (+/- 16.89) vs female 64.67 (+/- 14.99) mm Hg; df: 5669; P < 0.0000; CI: -2.65, -0.989. Proteinuria (macroalbuminuria) was found to correlate positively and very significantly with both systolic and diastolic blood pressure: for SBP: r = 0.074, P < 0.0001; DBP: r = 0.055, P < 0.0001. Perhaps more significantly, in the context of preventive nephrology, is the observation that the intercept of the regression line with blood pressure was below the level conventionally regarded as hypertensive, suggesting that nephron damage may have occurred at this lower level. Overall mean diastolic blood pressure but not systolic was found to be significantly higher in the rural environment than the urban setting: mean rural DBP: 66.43 (+/- 15.699) vs urban: 62.78 (+/- 78); P < 0.00001; rural SBP: 113.71 (+/- 23.95) vs urban: 112.69 (+/- 19.87), P = NS. No discernible effect of consanguinity in marriage on blood pressure could be detected in this study but we believe that further details are required before a definite statement can be made on this important subject. The percentiles presented can only be regarded as foundation figures requiring further validation before they can be useful in determining cut-off levels for hypertension for the Saudi population.

The anti-stress activity of a gem-containing Unani formulation against diverse stressors

Drugs of mineral origin, especially gems, are extensively used in Tibb-e-Unani (Unani Medicine), both as single drugs and as compound formulations. But such drugs have not yet been adequately studied scientifically. Jawahir Mohra (JM) is one such, as yet unstudied, anti-stress Unani preparation, containing a few herbal and animal ingredients also. Therefore in the present study, a modified JM preparation was investigated for its anti-stress activity against physical, chemical and metabolic stimuli. The non-gem complement (NGC) of JM was also studied for action against physical stress. In albino rats stressed by swimming and subsequently tested for motor function by Rota rod (muscle coordination), activity wheel (forced motor activity) and photoactometer (spontaneous motor activity), JM treatment for 7 days produced a striking and significant increase in activity. The NGC also increased the activity significantly which was however less than JM. JM also produced a striking increase in cold swimming endurance and in the latency of post-anoxia convulsions, while pentylentetrazol (PTZ)-induced defecation and urination in an open field arena under continuous stimulation by intense light and sound was significantly decreased. Therefore, the present investigation indicates that the gem-containing Unani compound JM has significant anti-stress activity of a non-specific type against diverse stressors. This could be due to adaptogenic activity of the preparation. The study also shows that the gems in JM contribute significantly to its anti-stress activity.

Contrasting influence of the living environment and gender on systemic hypertension in Saudi population of Gassim, Saudi Arabia

In a cross-sectional total population survey of Faizia East Primary Health District of Buraidah, which is divided into an "urban" and "rural" sections, casual blood pressure was recorded in 5671 subjects. 2222 (910 males) were adults (> 19 years). 3299 (1561 males) were between 3-18 years, making the paediatric/adolescent cohort of the population. The rest were below 3 years and were not included for calculations in this report. For adults, HPN was defined as > or = 140/90 mm Hg and P/A it was > or = 95th percentile for the age cohorts 3-5, 6-9, 10-12, 13-15 and 16-18 years as recommended by The Task Force for Blood Pressure Control in Children (1987). Each of the three subsets of HPN were derived from these basic definitions without modification. In the adults population, overall prevalence (S/DHPN + ISHPN + IDHPN) was 23.58% (524/2222) and gender prevalence was marginal in favour of males (25.71 vs 22.1% for males and females respectively; OR: 1.22, chi square = 3.89; p = 0.05; CI: 1.00 < OR < 1.49). By contrast, overall HPN prevalence in P/A was 10.64% (351/3299) and in all the age cohorts, girls were very significantly more hypertensive than boys. Overall figures were 13.06 vs 7.94% respectively for girls and boys; OR: 0.57; chi square = 22.65; p < 0000019; CI: 0.45 < OR < 0.73. Only in severe HPN (> or = 99th percentile) in 16-18 year age cohort did male preponderance become obvious. When the influence of the living environment was examined, in adult population (urban: 40,001; rural: 1670 subjects), for all age cohorts the rural environment which is largely inhabited by the unsophisticated Bedouins living close to their livestock, significantly predisposed to HPN as compared to the urban setting. Overall figures are 19.95 vs 32.60%, urban vs rural respectively: OR: 0.52; chi square = 40.4; p < 0.000000; CI: 0.42 < OR < 0.64. On the other hand, in the P/A population (2301 urban, 998 rural) for the age cohorts 3-5 and 6-9 years the urban environment significantly predisposed to HPN. At 10-12 years the prevalence was virtually even (12.65 vs 12.71%; OR: 0.99; p: NS). Thereafter, i.e. 13-15, 16-18 year cohorts, the rural environment became more dominant, just like the adult pattern. In other words whatever the factors in the unsophisticated Bedouin "rural" setting which predisposes to HPN does not become operative until after childhood--after 12 years. This contrasting gender and environmental influence in our study population seems unique, being reported for the first time. It may be pointing us in new direction in the elucidation of the pathogenesis of HPN and should deserve further studies.

Doppler echocardiography in cardiac transplant patients: allograft rejection and its relationship to diastolic function

Right ventricular endomyocardial biopsy has been the traditional gold standard for determining cardiac transplant rejection. Although endomyocardial biopsy has proved useful in guiding rejection therapy, this procedure is not without risk. The objective of the present study was to determine whether a noninvasive method for assessing cardiac diastolic function would be of value in predicting biopsy scores. Doppler echocardiographic indices of left ventricular function were compared with biopsy scores in 43 studies from 23 patients (age 50 +/- 8 years). The average time from transplant to echocardiographic study was 1.5 years. Standard clinical indices of diastolic function failed to predict biopsy results. The A-Ar interval, evaluated in 36 studies, was found to significantly decrease (p < 0.003) with increasing biopsy scores. Preliminary results suggest that this echocardiographic parameter may prove useful in predicting biopsy results.

5-Hydroxytryptamine-induced calcium-channel gating in rainbow trout (Oncorhynchus mykiss) peripheral blood lymphocytes

The present study was conducted on peripheral blood lympho-cytes of rainbow trout (Oncorhynchus mykiss) to assess the role of 5-hydroxytryptamine (5-HT; 'serotonin') in calcium signalling. 5-HT-induced increases in intracellular free calcium concentrations, [Ca2+]i, and its action was mediated by 5-HT receptor subtype 3 (5-HT3), but not by 5-HT receptor subtype 1A (5-HT1A) or subtype 2 (5-HT2) in these cells. In Ca2+-containing medium (1 mM CaCl2), 5-HT and 2-methyl-5-HT (5-HT3 receptor agonist) induced increases in [Ca2+]i, whereas in Ca2+-free medium (0 Ca2+, 1 mM EGTA), these two agents failed to evoke increases in [Ca2+]i in these cells, demonstrating that 5-HT mobilizes Ca2+ from the extracellular environment. Furthermore, 5-HT-induced increases in [Ca2+]i are not contributed to by the intracellular endoplasmic reticulum (ER) pool, as thapsigargin, an agent that recruits Ca2+ from ER stores, had additive effects on 5-HT-induced [Ca2+]i responses in fish peripheral lymphocytes. 5-HT-induced increases in [Ca2+]i were mediated by 5-HT3 receptors via gating the calcium through L-type, but not N-type, calcium channels in trout lymphocytes.

Mucous membrane plasmacytosis of the upper aerodigestive tract. A case report with effective treatment

We present a case of plasmacytosis of the mucous membrane of the upper aerodigestive tract. This is a rare benign condition characterized by plasma cell infiltration of the mucosa, with only nine cases described previously (Ferreiro et al., 1994). The lesions, which have a cobblestone appearance, cause throat discomfort, dysphonia and mild dyspnoea. All the cases described previously failed to respond to antibiotics, systemic steroids, or to surgical resection. The present case has however responded favourably to intensive and prolonged treatment with beclamethasone oral spray and Corsodyl mouthwashes.

Identification of lymphocyte 5-HT3 receptor subtype and its implication in fish T-cell proliferation

In the present study, we identified the serotonergic receptor of type 3 (5-HT3) on the lymphocytes of a teleost fish, Oncorhynchus mykiss. In the pharmacological studies on the binding of [3H]serotonin to membrane receptor sites, 2-methyl-5-HT, an agonist of 5-HT3 receptors, displaced the binding of [3H]serotonin to fish lymphocytes, indicating the presence of 5-HT3 receptors on these cells. The known antagonists of the mammalian 5-HT3 receptor, ICS-205-930 and metoclopramide, failed to displace [3H]serotonin binding to lymphocytes during the period of association equilibrium (8 min); however, these antagonists progressively displaced [3H]serotonin binding from 10 to 40 min of incubation. These results suggest that fish 5-HT3 lymphocyte receptors may differ pharmacologically from mammalian receptors. As mammalian 5-HT3 receptors are coupled with Na+ inward movements, we undertook a study on Na+ influx by using SBFI/AM, a fluorescent probe. In SBFI/AM loaded fish lymphocytes, 2-methyl-5-HT leaked Na+ inward movements. Prior incubation of lymphocytes for 30 min in the presence of 5-HT3 antagonists, ICS-205-930, metoclopramide and MDL-72222, curtailed significantly the Na+ influx evoked by 2-methyl-5-HT, demonstrating that Na+ is leaked into fish lymphocytes via the 5-HT3 receptor-channel whose functioning is blocked by these antagonists. Furthermore, 2-methyl-5-HT exerted immunosuppressive effects in a dose dependent manner on fish T-lymphocytes stimulated by phytohaemagglutinin (PHA). Serotonin and 2-methyl-5-HT blocked the cell cycle progression of PHA-stimulated T-cells from G0/G1 to S phase. The immunosuppressive effects of 2-methyl-5-HT on T-cells were partially reversed by the antagonists, metoclopramide and ICS-205-930; however, the latter antagonist at high concentrations synergized with the immunosuppressive effects of 2-methyl-5-HT. These results demonstrate that the fish lymphocyte 5-HT3 receptor, which may be pharmacologically different from mammalian receptor subtype, is functionally implicated in fish T-cell proliferation.

Studies on preventive nephrology: Systemic hypertension in the pediatric and adolescent population of Gassim, Saudi Arabia

Casual blood pressure was recorded for subjects of Faizia East Primary Health District during a cross-sectional population survey. Valid information was obtained from 5671 subjects, out of which 3299 (1561 males and 1738 females) were between the ages of three and 18, constituting therefore the pediatric/adolescent (P/A) sector of our study population. The prevalence of hypertension (HPN), defined as A(3) 95th percentile for total HPN population (mild and severe) and A(3) 99th percentile for severe, was calculated for the three-year age cohorts suggested by the Task Force on Blood Pressure Control in Children (1987). The three subsets of HPN were derived from the suggested cut-off levels without any modifications. Overall prevalence of HPN was, for the P/A, found to be 10.65% (351/3299). Females in all the age cohorts were significantly more hypertensive than males, overall gender prevalence being 7.94% (124/1561) for males against 13.06% (227/1738) for females: P=0.0000019; CI: 0.45<OR7lt;0.73. One hundred and twenty-eight subjects (3.88%) had severe HPN, again with gender difference in favor of females (2.57 versus 5.06%), P=0.00022; CI: 0.33<OR<0.74). Sixty-seven and a half percent (237/351) of the HPN population were in the six to 12 year age group, with the significant gender difference persisting (P=0.000407; CI: 0.41<OR<0.74). Ninety-four of these (73.44%) had the severe HPN, with similarly significant gender difference (P=0.0018; CI: 0.31<OR<0.79). Significantly, 67% of gross proteinuria for the entire population has been found in the same age cohort with the same significant gender difference. ISHPN was found to constitute 51.57% (181/351) of the HPN population, followed by IDHPN with 32.48% (114/351) and S/DHPN the least with 15.95% (56/351). The significant gender difference in favor of females noted seems to be unique to the Saudi population. Similarly, the preponderance of ISHPN subsets is, to our knowledge, being recorded from the first time in literature. When coupled with the pattern of proteinuria, we believe that, in the context of preventive nephrology, greater attention will need to be devoted to the pediatric population, especially females.

Ca2+/calmodulin and protein kinase C regulation of serotonin transport in human K562 lymphocytes

This study was conducted on human K562 lymphocytes to investigate the mechanisms implicated in the regulation of the serotonin transport process. The uptake of serotonin in these cells was saturable (Km, 3.37 microM; Vmax, 2.03 nmol/10(6) cells) and Na+ dependent; isoosmotic replacement of Na+ with choline chloride in the assay medium resulted in the decreased uptake process. Augmentation of intracellular free calcium, [Ca2+]i, by thapsigargin decreased the uptake of serotonin in these cells. Similarly, addition of calcium ionophores (A23187) and ionomycin also inhibited serotonin transport. In Fura-2-loaded cells, these agents increased the [Ca2+]i contents. These results suggest that an increase in [Ca2+]i is implicated with a decrease in serotonin transport. Since an increase in [Ca2+]i is known to activate calmodulin (CaM), we employed CaM antagonists. Calmodulin antagonists W-7 (N-[6-aminohexyl]-5-chloro-1-naphthalene-sulfonamide) and mellitin inhibited serotonin uptake in K562 cells, suggesting that CaM is involved in serotonin transport regulation. Furthermore, acute exposure of K562 cells to known protein kinase C (PKC) activators, phorbol-12-myristate-13-acetate (PMA) and sn-1,2-dioctanoylglycerol (DiC8), curtailed serotonin uptake by these cells. However, staurosporine (a PKC inhibitor) failed to abolish the inhibitory effects of PMA on serotonin transport in these cells, indicating that the target of PMA is not PKC. Nonetheless, the PMA-induced inhibitory effects are specific as 4 alpha-phorbol-12,13,didecanoate (a phorbol ester known not to activate PKC) failed to mimic PMA-like actions on serotonin transport in K562 cells. DiC8 not only exerted higher inhibitory effects than PMA but also had additive effects in the presence of the latter on serotonin transport. These results suggest that in addition to PKC, there are other cellular targets (of PMA) implicated in serotonin transport regulation.

Putrescine modulation of depolarization-induced [3H]serotonin release from fish brain synaptosomes

In this study, we investigated the effects of putrescine, a precursor of polyamine metabolism, on depolarization (potassium chloride, KCl)-induced [3H]serotonin (5-hydroxytryptamine (5-HT)) release from brain synaptosomes of rainbow trout (Oncorhynchus mykiss). An irreversible inhibitor of polyamine metabolism, difluoromethyl-ornithine (DFMO), inhibited the KCl-induced [3H]serotonin efflux, and addition of putrescine (PUT) reversed the inhibitory effects of the former in synaptosomal preparations. In Fura-2/AM loaded synaptosomes, KCl stimulated Ca2+ influx. Hence, prior addition of EGTA abolished the KCl-induced Ca2+ responses, indicating that KCl-induced depolarization recruited Ca2+ from extracellular medium. The DFMO curtailed the KCl-evoked Ca2+ influx, and addition of PUT reversed the inhibitory effects of DFMO. Furthermore, fish brain was found to contain polyamines in high amounts (e.g. putrescine from 600 +/- 20 to 850 +/- 30 nmol/g protein). These results suggest that polyamine putrescine, present in fish brain, might be involved in [3H]serotonin efflux via Ca2+ influx mechanisms.

Serotonin modulation of lymphocyte proliferation via 5-HT1A receptors in rainbow trout (Oncorhynchus mykiss)

In this study, the effects of serotonin (5-HT) on in vitro lymphoproliferation in rainbow trout (Oncorhynchus mykiss) are investigated. Serotonin exerted immunosuppressive effects on lipopolysaccharide (LPS) and phytohemagglutinin (PHA)-stimulated proliferation of fish peripheral blood lymphocytes (PBL). 8-OH-DPAT (an agonist of 5-HT1A receptors) mimicked the inhibitory effects of serotonin on lymphocyte proliferation, whereas addition of spiperone (an antagonist of 5-HT1A and 5-HT1B receptors) reversed these inhibitory effects, indicating that 5-HT1A receptors may be implicated in serotonin-induced immunosuppression. Furthermore, in this study the serotonergic receptors present on fish peripheral lymphocytes were characterized. A Scatchard plot of serotonin binding to fish lymphocytes followed the 'bell' shape curve with a Bmax of 0.63 microM and a Kd of 1.54 x 10(-8) M/10(6) cells. These results demonstrate the presence of positive-type co-operation among receptor populations. In a displacement study, serotonin inhibited the binding of 3H-5HT to the receptor sites both in resting and LPS/PHA-stimulated trout lymphocytes. Interestingly, the agonists (8-OH-DPAT and buspirone) and antagonist (NAN-190) of the 5-HT1A receptor subtype failed to displace 3H-5HT binding to receptor sites in resting cells, whereas these agents inhibited 3H-5HT binding in LPS- and PHA-stimulated lymphocytes significantly, suggesting that after mitogenic stimulation, 5-HT1A receptors are expressed on lymphocytes. CGS-12066B (an agonist of 5-HT1B receptors) failed to influence significantly 3H-5HT binding to receptor sites both in resting and mitogen-stimulated lymphocytes, indicating that the 5-HT receptor subpopulation is not expressed either on resting or on LPS- or PHA-stimulated lymphocytes. Taken together, these results suggest that trout peripheral blood lymphocytes express functional serotonergic receptors, and 5-HT1A receptors, which are not expressed by resting lymphocytes, are expressed after mitogenic stimulation and implicated in the inhibition of mitogenic (LPS and PHA) responses.

Male sexual behaviour not abolished after medial preoptic lesion in adult rats

N-methyl-D-aspartic acid (NMDA) was injected into the medial preoptic area (mPOA) of 10 rats to destroy the neurones in this region. Male sexual behaviour was scored before, and on days 2, 6, 10, 17, 24 and 31 after the administration of NMDA. The neurones in the injection site were destroyed in all the rats, but male sexual behaviour was only transiently reduced in the animals with lesions largely restricted to the mPOA. These findings are in contrast to the earlier reports of permanent suppression of sexual behaviour after electrolytic lesion, with damage to the neurones and fibres of passage. The present study shows that the mating behaviour could be expressed even after the destruction of the neurones in the mPOA.

Exophthalmos and facial swelling: a case of limited Churg-Strauss syndrome

We report a case of vasculitis causing facial swelling and exophthalmos which on clinical and histological grounds is thought to be limited Churg-Strauss syndrome. An excellent response was achieved to high doses of systemic steroids and cyclophosphamide.

Magnetic resonance imaging of NMDA-induced lesion of the medial preoptic area and changes in sleep, temperature and sex behaviour

Destruction of the medial preoptic area (mPOA) neurons of rat brain, induced by intracerebral injection of N-methyl D-aspartic acid (NMDA), has been studied by employing the non-invasive Magnetic Resonance Imaging (MRI) technique. Changes in the MRI images are compared and correlated with the functional changes after the mPOA lesion. The progress of the lesion at the injected site has been monitored (using MRI) from 15 min to 1 month after the stereotaxic microinfusion of NMDA (5 micrograms in 0.2 microliter). This study shows that the localised hyperintense (bright) area starts appearing at the mPOA from 3 h after NMDA injection, and the brightness increases progressively for about 2 days. The size and brightness of hyperintense area decrease thereafter. It has not been possible to locate the lesion site after 3 days, using MRI, except in one rat where a vacuole-like area was seen at the NMDA injected site on postmortem histological examination. The reduction in sleep after the mPOA lesion does not show any correlation with the changes in MRI, as it persists throughout the 3 weeks of recording. On the other hand, the initial drastic reduction in male sex behaviour and the increase in body temperature correlated to some extent with the increased brightness in MRI at the site of lesion. The size and location of the hyperintense area, observed during the first 2 days, match with the lesioned area which was histologically identified after 1 month of NMDA administration. Control administration of normal saline into the mPOA did not produce any alteration in the brightness of the MRI image and practically no loss of neurons at the injected site. Though some functional changes have correlation with the alteration in MRI, this cannot be used to interpret the changes in all the physiological parameters. This study also demonstrates that the disappearance of the brightness in MRI should not be taken to indicate a positive prognosis. Though the lesion could not be seen in MRI within 2 hours, its detection after 3-4 h (but within 3 days) after NMDA lesion would give very valuable information for long term studies.

Studies on preventive nephrology: pattern of the subsets of hypertension in the paediatric, adolescent and adult population of Gassim, Saudi Arabia

As part of our studies in preventive nephrology, we have recorded the casual blood pressure during a total population cross-sectional survey of the Faizia East Primary Health District (FEPHD). A total of 5671 subjects had adequate records. Of these 2222 were adults (> 19 years). The prevalence of systemic hypertension (HPN) was calculated, using as cut-off levels, > or = 140/90 for the adult population and > or = 95th percentile as recommended by the Task Force for Blood Pressure Control in Children (1987) for the paediatric and adolescents (3-18 years). Using these definitions without modification, the three subsets of HPN viz. combined systolic/diastolic (S/DHPN), isolated systolic (ISHPN) and isolated diastolic (IDHPN) were derived for each of the age cohorts studied-10-year age cohorts for the adults and the Task Force 3-year age cohorts for the paediatric/adolescent (P/A) population. In both adult and P/A population ISHPN constituted the bulk of the hypertensive population (56.68% for the adults and 51.57% for P/A). the IDHPN subset was the least for adults making up 11.64% while the S/DHPN was in between constituting 31.68%: For the P/A population S/DHPN was the least, 15.95% and IDHPN (32.48%) was in between. When distributed into 10-year age cohorts for the adults, ISHPN showed the steepest gradient depicting increasing prevalence with advancing age. On the other hand, IDHPN did not rise with age; if at all, it tended to fall. The slope for S/DHPN was sandwiched in between. For the P/A population, for all the 3-year age cohorts, and for all the three subsets, there was an initial peak in childhood followed by a decline in adolescence. However, some variations were discernible in each subset. ISHPN in girls peaked at 10-12 before declining but in boys it virtually followed an even keel. IDHPN, in both boys and girls peaked sharply at 6-9 before a rapid decline in prevalence into adolescence. S/DHPN also peaked at 6-9 but both the upward slope and the subsequent decline were more gentle than the other subsets. When viewed together for our study population, assuming equivalence in cut-off levels for HPN, both ISHPN and S/DHPN seem to exhibit a bimodal curve, with one peak in childhood and a second rise in adulthood continuing into old age. IDHPN showed a unimodal curve, with the one peak in childhood followed by a continuing decline through adolescence into adulthood to virtual disappearance in old age. We believe these slopes may have prognostic significance which are not entirely clear at the moment but our findings reinforce the importance of the systolic blood pressure and that diastolic blood pressure alone should no longer be used as the index treatment or complication of high blood pressure.

Determination of erythrocyte polyamines as a predictive method in tumour diagnosis. An animal study with chemically induced tumours

There have been numerous attempts in the past to use polyamine determinations in body fluids for tumour diagnosis. Since spermidine (Spd) and spermine (Spm) are mainly transported in blood by erythrocytes, this study was concerned with the diagnostic possibilities of red blood cell (RBC) polyamine determinations. In tumour-grafted animals we observed that RBC polyamine levels correlated with the tumour mass progression and increased before the tumour was palpable. Discrepancies between the evolution of RBC polyamine levels in tumour-grafted animals and in cancer patients were probably due to the non-continuous growth of the tumours in patients. Therefore, an animal model was sought which mimicked the clinical situation. In the present experiments, ethylnitrosourea induced tumours were used which, in analogy to the clinical situation, had an undetermined time of the appearance in a non-predetermined proportion of the animals. RBC polyamines were determined over a period of 7 months in 154 rats. A total of 2,290 RBC polyamine determinations were performed during this study. The data clearly demonstrate the appearance of elevated Spd concentrations in advance of tumour diagnosis by conventional clinical methods. In 71% of the rats which later developed a tumour, abnormal Spd levels (> 40 nmol/8.109 RBC) preceded, by 35 +/- 31 days, the first clinical symptoms for the presence of a tumour. In 29% of the animals, abnormal RBC Spd concentrations were observed at the time of tumour diagnosis. Elevation of Spm concentrations (> 6 nmol/8.10(9) RBC) was less frequent. RBC polyamine levels did not allow discrimination between malignant and non malignant tumours. This confirms earlier findings that RBC polyamines are markers of the cell proliferation rate, but not for the presence of a malignant tumour. Elevated RBC polyamine concentrations are an index of the intensity of hyperplastic processes, which can be clinically used for the early detection of proliferative phases of tumours, thus allowing timely therapeutic measures.

Serotonin-induced calcium signaling via 5-HT1A receptors in human leukemia (K 562) cells

In this study, serotonin (5-HT) was found to diminish the intracellular calcium, [Ca2+]i, concentrations in a dose-dependent manner in Fura-2-loaded human leukemia (K 562) cells. Prior addition of verapamil (a calcium channel blocker) to the cells abolished the serotonin-induced response, suggesting that the diminution of free [Ca2+]i contents was due to the opening of calcium channels. Thapsigargin (an agent which increases [Ca2+]i via its action on endoplasmic reticulum) augmented the [Ca2+]i contents. Addition of serotonin before or after thapsigargin (THAP) curtailed the THAP-stimulated increases in [Ca2+]i, supporting the notion that 5-HT acts on the calcium channels and that it empties, in part, the THAP-stimulated calcium contents. Spiperone and NAN-190, antagonists to 5-HT1A receptor subtype, abolished the serotonin effects on calcium signaling, whereas an agonist to 5-HT1A receptor, 8OHDPAT, mimicked the serotonin-like action on the diminution of the intracellular calcium contents. These results indicate that the 5-HT response is mediated via 5-HT1A serotonergic receptors in these cells. Furthermore, we characterized the 5-HT receptors in K 562 cells. The specific binding of serotonin to these cells was saturable and hyperbolic. The Kd and the Bmax of serotonin binding were 100 nM and 1690 fmol/10(6) cells, respectively. 8-[3H]OH-DPAT also labeled these cells with a Bmax of 2.8 fmol/10(6) cells and a Kd of 20 nM. The specific binding of 8-[3H]OH-DPAT to K 562 cells was displaced by serotonin, 8OH-DPAT, and NAN-190. These results suggest that K 562 cells possess functional 5-HT1A receptors coupled with calcium signaling.

The role of the anti-sperm autoantibodies in the management of patients with primary infertility

The role of antibody mediated infertility in patients with primary/secondary unexplained infertility is the subject of current interest worldwide. A prospective study was conducted to study the role of anti sperm antibodies in Pakistani patients with infertility. Patients reporting in the outpatient clinic of a local gynaecology department with problem of infertility were subjected to a detailed scrutiny by history and clinical examination including post-coital test and hysterosalpingography. Hormonal profile consisting of serum FSH, LH, Prolactin and Progesterone was assessed. Most of the ladies also underwent a pelviscopic examination. A total of 117 patients were selected where post-coital test was abnormal, semen analysis was not satisfactory or who had unexplained infertility. Tests were performed on the serum specimen from the husbands, wives and in some cases on the seminal plasma as well, for the measurement of the anti sperm agglutinating and anti-sperm immobilizing antibodies by the microagglutination technique. Fifteen of these patients were found positive for these antibodies, 7 were positive for the agglutinating antibody, 6 for the immobilizing antibody and two for both types. These results indicate that immunomodulation may be responsible for some cases of infertility in our population.

Three dimensional culture of pineal cell aggregates: a model of cell-cell co-operation

Three dimensional (3-D) cultures of pineal cell aggregates were obtained by constant gyratory shaking the heterogenous cell populations, obtained from the rat pineals, in the DMEM (Dulbecco's modified Eagle's medium). Within 4 days, the pineal cells became organized into a tissue like configuration appearing as a compact ball, evidenced by the scanning electron microscopy. The 3-D aggregates seemed to be mainly composed of pinealocytes (round-oval cells), glial (elongated cells) and other unknown cells. The heterogenous cells were separated by intercellular spaces. The ultrastructural characteristics revealed by transmission electron microscopy exhibited the presence of granular lysosomes, typical of pinealocytes actively involved in the secretion. These pineal cell aggregates secreted melatonin and other indole amines i.e. 5-methoxytryptamine (5-MT), indole acetic acid (IAA), 5-methoxy-3-indole acetic acid (5-MIAA), tryptophol (TOL) and 5-methoxytryptophol (5-MTL) in the culture medium, indicating the functional aspect of pinealocytes. The 3-D aggregates cultures had advantages over the pineal monolayer cultures as, after 4 days of culture, the amounts of indole amines secreted by 3-D aggregates were higher than those secreted by monolayer cultures. Besides, the 3-D aggregates remained functional till 24 days in the gyratory culture conditions. In the continuous perifusion system, the 3-D aggregates secreted melatonin while challanged with isoproterenol. This 3-D model of pineal cell aggregates might be useful, in future, to perform other kinetic studies of the release of indole amines in perifusion experiments as this system allows the maintenance of pineal cells for a long period of time.

Structure-activity relationship of phenolic compounds (phenol, pyrocatechol and hydroquinone) on natural lymphocytotoxicity of carp (Cyprinus carpio)

We have tested the effects of phenol and two diphenols (pyrocatechol and hydroquinone) on a non-specific immune response, i.e. the natural cytotoxic activity, of the carp. After a 12-day exposure of fish, at a concentration of 0.1 mg/l, hydroquinone appeared to exert the most immunotoxic effect in vivo. In vitro, after a preincubation of 1 h, phenol (10(-2) M), pyrocatechol (4.25 x 10(-4) M) and hydroquinone (4.25 x 10(-5) M) decreased the natural cytotoxic activity of lymphoid cell suspension. In vivo and in vitro experiments show that hydroquinone is the most toxic compound, whereas diphenols are more toxic than phenol. These results demonstrate that the study of immune systems can reveal the presence of toxic substances with varying degrees of toxicity. Also, the position of a second hydroxic group on the benzonic nucleus seems to influence the compound toxicity.

Rat pineal cell aggregates: ultrastructural and functional characteristics

The aggregates were obtained by constant gyratory shaking of suspension cells freshly isolated from adult rat pineal glands. Their sizes ranged from 60 to 120 microns. Within 4-5 days, the aggregates formed by pinealocytes, astrocytes, and other unidentified cells became organized in a tissue-like configuration. There was no proliferation of the fibroblast cells. Ultrastructural characteristics of the aggregates were revealed by the presence of granular lysosomes, which are typical of pinealocytes, and are actively involved in the secretion. Functional characteristics were studied in static incubation. The aggregates secreted melatonin and other indole amines in culture medium. Basal melatonin release was detected until Day 24 of culture. This secretion was stimulated 230% with Isoproterenol (beta-adrenergic agonist), 725% with Epinephrine (alpha- and beta-adrenergic agonists), and 140% with Vasoactive Intestinal Peptide after 5 days in culture, then > 1200% with Forskolin 9 days later (14-day-old aggregates). The results indicate that three-dimensional aggregates obtained from isolated pineal gland cells were the functional multicellular structures with in vivo characteristics.

Immunophysiology: the immune system as a multifunctional physiological unit

In this review, the immune system is described as a physiological system in its functions and relations with other organs. Hence, communications are mediated by common receptors and cytokines. The immunophysiology is a bidirectional system where the immune system is influenced by endocrine apparatus and vice versa. At the cellular level, we have attempted to define this "cross-talk" by proposing one- or two-signal models, where the first signal is mediated via binding of hormones or neurohormones to the lymphocytes and the second signal is generated by binding of the antigen to the recognition sites or of cytokines to their lymphocyte receptors. The physiological reality of these interrelationships is discussed.

First cleft branchial fistula in a child--a modified surgical technique

Congenital first branchial cleft fistulae, their embryology, anomalies, varied relationships to the facial nerve and surgical techniques for their excision have been well described in the literature. We report a case of a type II first cleft fistula in a three-year-old child which required a modification of the standard surgical approach to achieve safe and complete excision with identification and preservation of the facial nerve.

Internalization of metformin is necessary for its action on potentiating the insulin-induced Xenopus laevis oocyte maturation

In this study, metformin (N, N1 dimethylbiguanide) was found to potentiate insulin-induced Xenopus laevis oocyte maturation, a phenomenon of transition from late G2 to M phase of the cell cycle. These cells also accumulated exogenous metformin (130 +/- 6.5 nmol/oocyte). Metformin covalently-coupled to Sepharose 4B beads failed to potentiate the insulin-induced oocyte maturation which suggests that these cells did not take up metformin from the extracellular medium. Addition of metformin alone to Xenopus laevis oocytes did not induce the maturation process, though these cells took up exogenous metformin. Micro-injection of metformin (120 nmol/oocyte) to oocytes accelerated the insulin-induced maturation, but it was lower than in cells which were incubated with free metformin together with insulin. Interestingly, insulin had no effect on metformin uptake by the oocytes. Methylglyoxal-bis(guanylhydrazone), MGBG, an apparent analogue of metformin, induced oocyte maturation. Addition of metformin, either free or Sepharose-bound, did not influence the MGBG-induced 60% maturation of Xenopus laevis oocytes. These results suggest that the internalization of metformin is necessary for its action and its effects are specific on insulin activity.

Transport and metabolism of polyamines in wild and multidrug resistant human leukemia (K 562) cells

Multidrug resistance (MDR) can be defined as the resistance of cancer cells not just to chemotherapeutic agents to which they have been exposed but also to other apparently unrelated compounds. This MDR phenotype is commonly associated with the high expression of levels of 170 kDa P-glycoprotein, encoded by MDR genes. In the present study, the uptake kinetics of polyamines and their biosynthesis were studied in wild and multidrug resistant (MDR) K 562 cells in culture. The rate (Vmax) of polyamine uptake was significantly lower in MDR cells than that in wild type cells, whereas the Km for the uptake was not significantly different in these cells, suggesting that polyamine transporter is not modified in MDR cells, though their different physiological state influences the uptake process. In a 32 h chase, the transported radioactive polyamines were gradually interconverted. [14C]putrescine was converted into [14C]spermidine following between 15 min and 32 h of culture, and into [14C]-spermine after 16 h of culture, in both the cell types; however, the levels of interconverted radioactive polyamines were always lower in MDR cells as compared with wild type cells. Similarly, internalized [14C]spermidine was converted into [14C]spermine, but not into [14C]putrescine in both the cells types. [14C]spermidine is metabolized into [14C]spermine after 4 h of culture in wild type cells, whereas in MDR cells the interconversion of [14C]spermidine into [14C]spermine is seen only after 16 h of culture. Blocking of the transmembrane drug efflux pump, expressed in the MDR cells, by preincubation in the presence of verapamil, did not influence the uptake of either of the two polyamines (putrescine and spermidine) by MDR cells. On the contrary, this kind of preincubation of wild type cells in the presence of verapamil significantly increased the uptake of these two polyamines. The levels of intracellular polyamine contents in MDR cells were always lower than those in the parental cell line. These results demonstrate that MDR cells are defective in both the uptake of polyamines and their biosynthesis as compared with wild type cells.

Management of orthotopic heart transplant recipients at Brooke Army Medical Center

Advances in heart transplantation and post-operative rejection therapy have given new hope to patients with end-stage congestive heart failure and cardiomyopathies. The growing numbers of pre- and post-transplant patients and the complexity of their care underscore the need for a multispecialty approach to patient management. This study examines the success of a multi-service program at Brooke Army Medical Center which offers pre- and post-transplant care to active duty, dependent, and retired military personnel.

Cellular origins of tenascin in the developing nervous system

We have used in situ hybridization and reverse transcriptase polymerase chain reaction (PCR) to study the origins of the extracellular matrix glycoprotein tenascin during the development of the central and peripheral nervous systems. Previous studies have shown that neural crest cells migrate along pathways that are lined with tenascin. In situ hybridization, PCR, and western blotting reveal that these cells themselves are a major source of tenascin both in vitro and in the embryo. Thus, tenascin is probably not acting as a guidance molecule but is more likely to be promoting neural crest cell motility in a more general way. Similarly, subpopulations of proliferating and migrating glia make tenascin in the developing central nervous system, as do the radial glia that are used as a substratum for migrating neuronal cell bodies. In the adult, tenascin continues to be expressed in the cerebellum by Golgi epithelial cells. This expression, as well as the expression of tenascin in connective tissue, indicates that this molecule may also be playing a role in regulating differentiation. Finally, the distribution of tenascin transcripts in the developing brain and spinal cord is similar to the distribution of mRNAs encoding receptors for platelet-derived growth factor-AA and basic fibroblast growth factor. In vitro studies indicate that both of these factors are potential regulators of tenascin expression.

Polyamine transport regulation by calcium and calmodulin: role of Ca(2+)-ATPase

The study was conducted on human leukemia (K 562) cells to characterize the mechanisms implicated in the regulation of the polyamine spermidine (Spd) transport process. The antagonists of calmodulin, trifluoperazine (TFP), W-7 (N-[6-aminohexyl]-5-chloro-1-naphthelenesulfonamide), or mellitin inhibited significantly polyamine Spd uptake in these cells. The translocation of calmodulin towards plasma membrane and a concomitant decrease in its contents in cytosol were directly correlated with the time course increases similar to that of Spd uptake, indicating that calmodulin is recruited towards plasma membrane during the Spd transport process. Diminution of free intracellular calcium, (Ca2+)i, by preincubating the cells in BAPTA (bis[2-amino-5-methylphenoxyl]-ethane-N,N,N',N',-tetraacetate) buffer inhibited Spd transport significantly. Addition of lanthanum (LAN), a molecule known to inhibit Ca2+ efflux via Ca(2+)-ATPase, curtailed Spd uptake by these cells. LAN inhibited Vmax, but not the Km, of Spd uptake, indicating that the former does not directly interact with the polyamine transporter; rather it regulates the transport process, probably via its action on Ca(2+)-ATPase. Calmodulin-stimulated uptake of 45Ca2+ by inside-out vesicles of K 562 cells, a measure of Ca(2+)-ATPase activity. Furthermore, addition of LAN inhibited both basal and calmodulin-stimulated activity of Ca(2+)-ATPase. Thapsigargin (THAP), a molecule known to elevate (Ca2+)i due to its action on the endoplasmic reticulum, increased Spd transport whereas addition of LAN inhibited THAP-stimulated Spd transport activity. THAP increased free (Ca2+)i in these cells, and a pre-addition of LAN to these cells curtailed the THAP-stimulated increases of (Ca2+)i concentrations. Addition of Spd brought about elevations in (Ca2+)i contents. Caffeine also increased (Ca2+)i in these cells; however, it failed to stimulate significantly the Spd uptake process, indicating that (Ca2+)i which is involved in the regulation of polyamine transport pathways does not belong to the calcium-induced calcium-release (CICR) pool. Replacement of Ca2+ from the incubation medium (i.e., 0% Ca2+) resulted in higher uptake activity as compared to that in 100% Ca2+ medium, demonstrating that in 100% Ca2+ medium the calcium efflux process is quickly compensated by calcium refilling/influx from the extracellular medium, while in 0% Ca2+ medium there is perpetual efflux of (Ca2+)i which contributes to higher Spd uptake process. The results of this study suggest that an increase in free (Ca2+)i and its release from the cells via Ca(2+)-ATPase, and concomitant activation of calmodulin, which controls Ca(2+)-pump activity, are involved in the regulation of the Spd uptake process in human leukemia cells.

Characterization of metformin transport system in NIH 3T3 cells

The biochemical properties of the metformin transport system were studied in NIH 3T3 cells. 14C-metformin uptake appeared to be a sodium dependent process. Iso-osmotical replacement of Na+ by choline chloride in the assay medium resulted in a decrease of metformin uptake. Amiloride (200 microM) inhibited the metformin transport by 35% in these cells. Gramicidin, a channel ionophore, was the most effective in inhibiting the metformin transport as compared to valinomycin, a mobile ion carrier, and Ca2+ ionophore (A 23187). Loading of cells with asparagine, ornithine, or polylysine did not influence the uptake process. However, the addition of lysine or arginine significantly stimulated the metformin uptake by NIH 3T3 cells. Similarly, the addition of metformin stimulated the arginine uptake by these cells, suggesting that metformin shares the y+ transport system. Metformin inhibited competitively the uptake of 14C-spermidine, a molecule of the polyamine family, by NIH 3T3 cells, whereas the latter failed to influence the uptake of the former significantly by these cells. Incubation of NIH 3T3 cells in the presence of difluoromethyl-ornithine (a suicidal inhibitor of polyamine biosynthesis) stimulated the spermidine, but not the metformin, uptake by these cells. Interestingly, a prolonged incubation of these cells in the presence of metformin failed to down-regulate the spermidine transport process. The spermidine- and methylglyoxal-bis(guanylhydrazone), MGBG-transport deficient (3T3MG) cells which do not accumulate exogeneous spermidine or MGBG, took up 14C-metformin. However, 14C-metformin uptake by 3T3MG cells was lower than that by normal NIH 3T3 cells.

Protein kinase C inhibitor (H-7) potentiates antiproliferative effects of a polyamine biosynthesis inhibitor

In this study, a protein kinase C inhibitor, H-7, was found to potentiate the antiproliferative effects of difluoromethyl ornithine (DFMO), inhibitor of the polyamine biosynthesis, on NIH 3T3 and 3T3/SV40 cells in culture. Incubation of the cells with DFMO inhibited the cell growth, whereas the addition of polyamine spermidine to these cells restored the normal rate of cell proliferation with the fact that these cells took up the polyamine from the extracellular medium to compensate the intracellular needs. The addition of H-7 to both the 3T3 and 3T3/SV40 cells, inhibited the cell proliferation, though the level of inhibition was always lower than in those treated with the DFMO alone. The addition of H-7 to the DFMO containing cells potentiated the antiproliferative effects of the latter with the fact that the former inhibited the uptake of the spermidine, though there might be additional targets, like the protein kinase C, involved in the inhibition process.

Phorbol esters augment polyamine transport by influencing Na(+)-K+ pump in murine leukemia cells

In this report, we elucidate the role of Na(+)-K+ pump in the regulation of polyamine spermidine (Spd) transport in murine leukemia (L 1210) cells in culture. Ouabain, known to bind extracellularly to the alpha-subunit of the Na(+)-K+ pump, inhibits the pump activity. The L 1210 cells were found to possess ouabain binding sites at 7.5 fmol/10(6) cells. Ouabain significantly inhibited the Spd uptake in a dose-dependent manner. The maximum inhibition of Spd uptake by ouabain was observed beyond 200 microM. Spd transport was inversely correlated with the [3H]ouabain binding to L 1210 cells: an increase in the saturation of ouabain binding to L 1210 cells resulted in a decrease of the Spd uptake process. Treatment of L 1210 cells with protein kinase C activator phorbol esters increased the Spd transport and, also, ouabain-sensitive 86Rb+ uptake, a measure of the activity of the Na(+)-K+ pump. H-7, a protein kinase C inhibitor, significantly inhibited the ouabain-sensitive 86Rb+ uptake by L 1210 cells. Phorbol esters stimulated the level, but not the rate, of 22Na+ influx. Addition of H-7 to L 1210 cells inhibited the 22Na+ influx process. A concomitant phorbol ester-induced increase in 22Na+ influx, [14C]Spd uptake, together with the functioning of Na(+)-K+ pump, indicates the role of the "Na+ cycle" in the regulation of the polyamine transport process.