Behavioral and neuroendocrine responses in shy children

Previous research has shown that infants who display a high frequency of motor activity and negative affect at 4 months of age are likely to be behaviorally inhibited toddlers. We examined social behaviors, maternal report of temperament, salivary cortisol, and baseline startle responses at age 4 in a sample of children, some of whom displayed a high frequency of motor activity and negative affect at 4 months of age. Infants who displayed this temperamental profile were reported by their mothers as more shy at age 4 compared with other children. We also found that 4-year-olds who displayed a high frequency of wary behavior during peer play exhibited relatively high morning salivary cortisol, were reported as contemporaneously shy by their mothers, and were behaviorally inhibited at 14 months of age. There were no significant relations found between baseline startle and morning salivary cortisol and measures of shyness at age 4. We speculate that high levels of cortisol in shy children may induce changes in the amygdala, exacerbating their fearfulness.

In vitro adrenaline and collagen-induced mobilization of platelet calcium and its inhibition by naftopidil, doxazosin and nifedipine

AIMS

The aim of the study was to obtain further information regarding the modes of action of doxazosin, naftopidil and nifedipine on platelet function.

METHODS

We conducted an in vitro study of drug influences on adrenaline and collagen-induced mobilization of platelet calcium.

RESULTS

In the presence of fibrinogen (300 micrograms ml-1) both collagen (5 micrograms ml-1) and adrenaline (16 microM) stimulated the aggregation of washed platelets. Collagen induced a transient rise (+4.97 +/- 0.63 microM) in platelet Ca2+ concentration, [Ca2+]i, as measured using the photoprotein aequorin, which coincided with the onset of aggregation. Adrenaline induced a smaller rise (+3.6 +/- 0.96 microM) which, however, occurred after the onset of aggregation. Naftopidil, an alpha 1-adrenoreceptor antagonist produced a concentration-dependent inhibition of collagen-induced Ca2+ mobilization, maximum inhibition (22.9 +/- 4%, P < 0.05) occurring with 40 microM naftopidil. The inhibition of Ca2+ mobilization was not reflected by a concentration-dependent inhibition of platelet aggregation, although 40 microM naftopidil produced statistically significant inhibition (23.3 +/- 11.7%, P < 0.05). The adrenaline-induced rise in [Ca2+]i was inhibited dose dependently by naftopidil (e.g. 40 microM naftopidil, 100 +/- 0%, P < 0.05), as was aggregation (40 microM naftopidil, 100 +/- 0%, P < 0.05). Doxazosin, another alpha 1-adrenoreceptor blocker, inhibited Ca2+ mobilization induced by collagen to similar extents as for naftopidil (30 microM doxazosin, 17.4 +/- 2.5%, P < 0.05), but did not inhibit platelet aggregation. It also inhibited the adrenaline-induced rise in [Ca2+]i in a concentration-dependent manner (30 microM doxazosin, 37.6 +/- 13.7%, P < 0.05), significant inhibitions of platelet aggregation also being produced (30 microM, 49.6 +/- 17.2%, P < 0.05). As expected, the calcium channel blocker nifedipine produced concentration-dependent inhibitions of both collagen-induced Ca2+ mobilization (e.g. 28 microM nifedipine, 47.8 +/- 2.7%, P < 0.05) and aggregation (28 microM, 55.1 +/- 9.2%, P < 0.05).

CONCLUSIONS

These data indicate that the alpha 1-adrenoreceptor blockers, naftopidil and doxazosin, inhibit Ca2+ mobilization, this mechanism being possibly the means whereby these drugs inhibit platelet aggregation.

Opportunistic group G streptococcus infection of both prosthetic knee joints

A case of polyarticular sepsis from group G streptococcus is described in a patient with rheumatoid disease and decubitus ulcers. This is a rare condition which is often associated with a mosaic of predisposing factors and requires prompt and aggressive antimicrobial therapy.

Reduced platelet serotonin content and release in familial hypercholesterolaemia

Plasma and platelet serotonin (5-HT) concentrations, and resting and collagen-induced 5-HT release in platelet-rich plasma were studied in normal and familial hypercholesterolaemic (FH) subjects. Platelet 5-HT concentrations were significantly reduced (-37%, P < 0.01) in FH patients whilst mean plasma concentrations, although increased, were not significantly different from those in normal subjects. Platelet 5-HT correlated negatively with plasma cholesterol when the data for normal subjects and FH, patients were combined (r = -0.48, P = 0.005). It also correlated negatively with low-density lipoprotein (LDL) (FH data, r = -0.59, P = 0.03; normal and FH data, r = -0.49, P = 0.004) but positively with high-density lipoprotein (HDL) (FH r = 0.79, P = 0.001; normal and FH, r = 0.37, P = 0.03). Collagen (5-160 micrograms/ml) stimulated platelet 5-HT release occurred in a concentration-dependent manner. In FH patients stimulated 5-HT release was reduced (10 micrograms/ml collagen, -40%, P < 0.05) and accompanied by increased collagen EC50 values (P < 0.02). Resting 5-HT release was increased substantially in FH patients but not significantly. Our data provide evidence for a relationship between circulating cholesterol and platelet serotonergic mechanisms. It is proposed that abnormalities relating to platelet-plasma 5-HT dynamics, perhaps due to enhanced platelet activity or decreased platelet uptake, may contribute to the cardiovascular complications in FH.

Behavioral and neuroendocrine responses in shy children

Previous research has shown that infants who display a high frequency of motor activity and negative affect at 4 months of age are likely to be behaviorally inhibited toddlers. We examined social behaviors, maternal report of temperament, salivary cortisol, and baseline startle responses at age 4 in a sample of children, some of whom displayed a high frequency of motor activity and negative affect at 4 months of age. Infants who displayed this temperamental profile were reported by their mothers as more shy at age 4 compared with other children. We also found that 4-year-olds who displayed a high frequency of wary behavior during peer play exhibited relatively high morning salivary cortisol, were reported as contemporaneously shy by their mothers, and were behaviorally inhibited at 14 months of age. There were no significant relations found between baseline startle and morning salivary cortisol and measures of shyness at age 4. We speculate that high levels of cortisol in shy children may induce changes in the amygdala, exacerbating their fearfulness.

Necrotizing sarcoid granulomatosis with extrapulmonary involvement

Pulmonary lesions, with sarcoid-like granulomas exhibiting noncaseous necrosis, with associated granulomatous arteritis fulfil the diagnostic criteria of necrotizing sarcoid granulomatosis (NSG). We report the case of a woman who presented with recurrent headaches, transient right hemipareses and left-sided ophthalmoplegia. An excised left retro-orbital lesion demonstrated sarcoid like changes, and the illness responded to steroid therapy. Twelve years later, the patient developed a tumour in the right lung. The resected specimen showed the histological hallmarks of NSG, and careful review of the retro-orbital lesion, removed 12 years previously, revealed similar histology. Extrapulmonary involvement in NSG is rare and has been histologically proven on only one previous occasion. The presentation of necrotizing sarcoid granulomatosis in two different systems 12 years apart is unusual and was considered worth reporting.

Parenteral ganciclovir treatment of acute CMV infection in the immunocompetent host

The treatment with ganciclovir of two non-compromised patients who required hospitalisation with acute cytomegalovirus (CMV) infection is described. Ganciclovir has rarely been used in such circumstances but, in four previously reported patients and in the patients described here, a rapid response to therapy was seen. In contrast to previous reports, relatively short courses of treatment (3-5 days) were given to our patients. The drug was well tolerated in each case and may have a role to play in the treatment of severe acute CMV infection in the normal host.

Adverse drug reactions in a hospital general medical unit meriting notification to the Committee on Safety of Medicines

1. We have retrospectively analysed data collected by a local adverse drug reactions reporting scheme in an acute hospital medical setting and have determined the numbers and types of reactions that would have merited notification as yellow card reports according to the guidelines of the Committee on Safety of Medicines. 2. The data related to 20,695 consecutive acute general medical admissions on seven general medical wards (140 beds) and were collected over 3 years, from April 1990 to March 1993. 3. Over 3 years there were 1420 reports of suspected adverse drug reactions, a rate of 68.7 per 1000 admissions. 4. If the guidelines for reporting issued by the Committee on Safety of Medicines had been strictly followed, 477 yellow cards would have been sent (23.1 per 1000 admissions). In 357 of these reports (74.8%), the reaction had caused admission to hospital. Only 31 of the 477 potential cards (6.5%) involved black triangle drugs and 10 of these were for minor reactions. 5. Only 30 of the 477 potential yellow cards (6.3%) were known to have been sent. The majority of those reactions not reported were for drug-related admissions, most of which were for well-known reactions to established drugs. 6. We have confirmed and quantified the extent of under-reporting of serious suspected adverse drug reactions to the Committee on Safety of Medicines from our hospital medical unit.

Plasma nitrate concentration in infective gastroenteritis and inflammatory bowel disease

BACKGROUND

In subjects on a low nitrate diet, plasma nitrate concentration and urinary nitrate excretion are thought to reflect endogenous nitric oxide (NO) production, and have been reported to increase during infective and inflammatory bowel disease.

AIMS

To compare the extent of NO production in patients with infective versus non-infective forms of bowel dysfunction.

SUBJECTS

Four groups: 20 healthy, volunteer clerical and laboratory staff, 12 patients with irritable bowel syndrome, 19 patients with inflammatory bowel disease, and 20 patients with infective gastroenteritis.

METHODS

The plasma nitrate concentration was determined with a copper coated cadmium column and spectrophotometry. Mean and median plasma nitrate concentrations were calculated and compared within the four groups. Mann-Whitney distribution free rank testing was used to compare the median values.

RESULTS

Median plasma nitrate concentrations in the four groups were: controls 32.7 mumol/l; irritable bowel syndrome 35.5 mumol/l; inflammatory bowel disease 35.1 mumol/l; and gastroenteritis 117.9 mumol/l (p < 0.001 gastroenteritis v all other groups).

CONCLUSIONS

Plasma nitrate concentration could serve as a discriminant between infective and inflammatory or functional bowel disease in patients presenting with diarrhoea. It is not clear why there is considerable difference in endogenous nitrate synthesis in these two conditions, which are both characterised by severe gut inflammation.

Evidence for separate serotonin and catecholamine compartments in human platelets

Serotonin (5-HT) and the catecholamines (CA), noradrenaline (NA) and adrenaline (Ad), are platelet dense-granule constituents which influence platelet activity and vessel tone. Platelets accumulate 5-HT via an active process whilst CA uptake occurs mainly by passive diffusion. The platelet contents and collagen-stimulated efflux of 5-HT, NA and Ad were examined in normal individuals to establish whether relationships exist between these monoamines. Regression analysis revealed that platelet 5-HT was not related to platelet NA or Ad levels. Platelet NA, however, correlated positively with Ad (r = 0.61, P < 0.01). Collagen-induced release of all three monoamines occurred in a dose-dependent manner. The collagen EC50 values for 5-HT and CA release, however, differed and were greater for 5-HT release: 9.6 +/- 0.8 vs. 3.8 +/- 0.2 microgram/ml collagen, 5-HT vs. NA, P < 0.001; 9.6 +/- 0.8 vs. 3.9 +/- 0.5 microgram/ml, 5-HT vs Ad, P < 0.001. These data may reflect differences regarding the triggering mechanisms for 5-HT and CA release and provide evidence for separate compartments of intra-platelet 5-HT and CA and possibly distinct populations of 5-HT and CA containing dense granules and/or platelets.

ATP and SH3 binding sites in the protein kinase of the large subunit of herpes simplex virus type 2 of ribonucleotide reductase (ICP10)

The large subunit of herpes simplex virus type 2 ribonucleotide reductase (ICP10) is a multifunctional protein. It consists of a ribonucleotide reductase and a serine/threonine protein kinase (PK) domain, which has three proline-rich motifs consistent with SH3-binding sites at positions 140, 149, and 396. We used site-directed mutagenesis to identify amino acids required for kinase activity and interaction with signaling proteins. Mutation of Lys176 or Lys259 reduced PK activity (5-8-fold) and binding of the 14C-labeled ATP analog rho-fluorosulfonylbenzoyl 5'-adenosine (FSBA) but did not abrogate them. Enzymatic activity and FSBA binding were abrogated by mutation of both Lys residues, suggesting that either one can bind ATP. Mutation of Glu209 (PK catalytic motif III) virtually abrogated kinase activity in the presence of Mg2+ or Mn2+ ions, suggesting that Glu209 functions in ion-dependent PK activity. ICP10 bound the adaptor protein Grb2 in vitro. Mutation of the ICP10 proline-rich motifs at positions 396 and 149 reduced Grb2 binding 20- and 2-fold, respectively. Binding was abrogated by mutation of both motifs. Grb2 binding to wild type ICP10 was competed by a peptide for the Grb2 C-terminal SH3 motif, indicating that it involves the Grb2 C-terminal SH3.

Platelet 5-hydroxytryptamine is decreased in a preliminary group of depressed patients receiving the 5-hydroxytryptamine re-uptake inhibiting drug fluoxetine

1. In view of the importance of 5-hydroxytryptamine in coronary thrombosis, we wanted to know whether a potentially protective decrease in platelet 5-hydroxytryptamine could be achieved by treatment with an inhibitor of 5-hydroxytryptamine uptake, fluoxetine. 2. We studied 15 patients treated for psychiatric indications with fluoxetine, and compared the findings with those obtained with blood from 18 patients treated with amitriptyline and 13 controls previously treated for affective disorders. 3. Platelet-rich plasma 5-hydroxytryptamine levels were significantly decreased in the fluoxetine group (P < 0.005) but not in the amitriptyline group compared with the control group. 4. Collagen-induced aggregation in whole blood anticoagulated with hirudin was measured by sequential single platelet counting. The contribution of 5-hydroxytryptamine was assessed from the effect of adding the 5-hydroxytryptamine specific antagonist ICI 170809. This contribution was significantly decreased in the fluoxetine group but not in the amitriptyline group compared with the control group. 5. It is concluded that platelet 5-hydroxytryptamine is indeed decreased by fluoxetine, and we would predict a protective effect of fluoxetine against coronary thrombosis.

Antimicrobial effect of acidified nitrite on gut pathogens: importance of dietary nitrate in host defense

Dietary intake of nitrate generates salivary nitrite, which is acidified in the stomach, leading to a number of reactive intermediates of nitrogen, among which are the potentially carcinogenic N-nitrosamines. Acidified nitrite, however, also has antimicrobial activity which coincides with the formation of nitric oxide. The present study examines the antimicrobial effect in vitro of acidified nitrite on Salmonella enteritidis, Salmonella typhimurium, Yersinia enterocolitica, Shigella sonnei, and Escherichia coli O157. First-order regression plots showed a linear inverse relationship of log-transformed proton and nitrite concentrations with MICs and MBCs after 30 min, 2 h, and 24 h of exposure (P < 0.001 for all antibacterial activities). Susceptibility to the acidified nitrate solutions ranked as follows: Y. enterocolitica > S. enteritidis > S. typhimurium = Shigella sonnei > E. coli O157 (P < 0.05). Addition of SCN-, but not that of CI-, increased the antibacterial activity (paired t testing, P < 0.001). Generation of salivary nitrite from dietary nitrate may provide significant protection against gut pathogens in humans.

The protein kinase activity of the large subunit of herpes simplex virus type 2 ribonucleotide reductase (ICP10) fused to the extracellular domain of the epidermal growth factor receptor is ligand-inducible

The gene coding for the large subunit of herpes simplex virus type 2 ribonucleotide reductase (RR) (ICP10) has a unique 5' terminal domain the product of which has a serine/threonine (Ser/Thr) protein kinase (PK) catalytic domain preceded by a transmembrane (TM) segment. Because ICP10 localizes on the cell surface and is internalized by the endocytic pathway like an activated growth factor receptor (Hunter et al., 1995, Virology 210, 345-360), we asked whether it is ligand-inducible in order to examine whether it has intrinsic transphosphorylating activity. We constructed a chimeric expression vector that contains the extracellular and TM domains of the epidermal growth factor receptor (EGFR) joined to the intracellular PK and RR domains of ICP10 (pCH5) and established constitutively expressing cell lines in NIH3T3 2.2 cells that do not express EGFR. The chimeric protein, designated p210 CH5, localized to the surface of these cells as determined by immunofluorescent staining with MAb EGFR, and it bound 125I-EGF.p210 CH5 coprecipitated with protein species p170, p120, p88, p60, p44, p34, and p25. EGF treatment activated the PK activity of p210 CH5, resulting in its autophosphorylation and the phosphorylation of the p120, p88, and p34 species. Immunoprecipitation/immunoblotting with anti-ras-GAP antibody and phosphoamino acid analysis indicated that p120 is ras-GAP and it is phosphorylated on Ser/Thr residues. The identities of the phosphorylated p88 and p34 are still unknown. The data indicate that when fused to a ligand-regulated extracellular domain (EGFR), the ICP10 PK auto- and transphosphorylating activities are ligand-inducible. These findings support the interpretation that the ICP10 PK activity is intrinsic and indicate that ras-GAP is one of its phosphorylation substrates.

Community-acquired toxigenic Clostridium difficile diarrhoea in the normoxaemic elderly who have received no antimicrobials: soft evidence for ischaemic colitis?

We report three examples of community-acquired toxigenic Clostridium difficile diarrhoea in elderly patients who had neither received antimicrobial therapy nor been institutionalised. These cases stimulated interest in the non-antimicrobial changes which might predispose the host to C. difficile-related disease and raised the spectre of bowel ischaemia as a possible aetiological factor.

Hippocampal 5-HT1A receptor binding site densities, 5-HT1A receptor messenger ribonucleic acid abundance and serotonin levels parallel the activity of the hypothalamo-pituitary-adrenal axis in rats

We have previously demonstrated that susceptibility of the Lewis rat to inflammatory disease, compared to the relatively resistant Fischer F344 rat, is related to a hyporesponsive hypothalamopituitary adrenal axis to inflammatory and other stress mediators. Since 5-HT and the 5HT1A receptor are important stimulators of this axis, we have investigated the levels of 5-HT1A receptor binding sites and encoding mRNA, 5-HT and 5-hydroxyindole acetic acid in various brain regions of Lewis, Harlan Sprague Dawley and Fischer F344 rats. Lewis rats expressed significantly less hippocampal and frontal cortical 5-HT1A receptor binding sites and mRNA than Harlan Sprague-Dawley and Fischer F344 rats. Adrenalectomy increased the number of 5HT1A receptor binding sites and mRNA expression in the hippocampus of all three strains. The levels of hippocampal 5-HT in Fischer F344 rats were significantly greater than levels detected in the same regions for the other two strains. Hypothalamic 5-HT and 5-hydroxyindole acetic acid levels in Harlan Sprague-Dawley rats were higher than the same area from the other two strains. Adrenalectomy increased the levels of 5-hydroxyindole acetic acid in the hypothalamus of all three strains. We conclude that hippocampal 5-HT1A receptor densities and 5-HT levels in the rat parallel the the activity and responsiveness of the hypthalamopituitary-adrenal axis. We have published these data in an earlier report.

Intracellular internalization and signaling pathways triggered by the large subunit of HSV-2 ribonucleotide reductase (ICP10)

The large subunit of the HSV-2 ribonucleotide reductase (RR) (ICP10) is a chimera consisting of a serine threonine (Ser/Thr) protein kinase domain at the amino terminus and the RR domain at the carboxy terminus. Transformed human cells that constitutively express ICP10 (JHLa1) were stained with anti-LA-1 antibody (recognizes ICP10 amino acids 13-26) and immunogold-conjugated goat anti-rabbit IgG and were examined by electron microscopy. ICP10-associated gold particles were observed on the cell surface and in structures with ultrastructural characteristics of endocytic vesicles, multivesicular bodies, and lysosomes, consistent with endocytic internalization. ICP10 was also associated with the cytoskeleton fraction of JHLa1 cells and, at least in part, it colocalized with actin filaments. This was evidenced by immunoprecipitation of [35S]methionine-labeled cell fractions and immunofluorescent staining of Triton-treated cells with anti-LA-1 antibody and phalloidin. Endocytic localization of gold particles was not seen in cells that constitutively express the ICP10 transmembrane (TM)-deleted mutant p139TM (JHL15). p139TM did not associate with the cytoskeleton and was almost entirely localized within the cytoplasm. raf and Erk evidenced decreased mobility consistent with an activated state in JHLa1, but not JHL15, cells, and chloramphenicol acetyl transferase (CAT) expression from a c-fos/cat hybrid construct was significantly increased in JHLa1 but not JHL15 cells. The data indicate that effector molecules downstream of ras are activated in JHLa1 cells and the ICP10 TM segment plays a critical role in ICP10 intracellular localization and its ability to activate signaling pathways. This behavior is analogous to that of an activated growth factor receptor kinase.

Plasma nitrate concentration and urinary nitrate excretion in patients with gastroenteritis

The concentration of nitrate (the stable oxidation product of nitric oxide) in plasma and its excretion in urine was measured in 20 patients with a diagnosis of gastroenteritis. On day 1 of the illness plasma nitrate concentration was significantly elevated compared with a healthy control population (92.7 +/- 17.0 mumol/l vs. 33.1 +/- 1.6 mumol/l; P < 0.001) and continued to be elevated on days 2 and 3. Urinary nitrate excretion was also elevated. The plasma nitrate concentration correlated with disease severity as assessed by stool frequency and plasma urea concentration. Plasma nitrate concentration may be a sensitive and clinically useful indicator of severity of gastroenteritis.

Ecstasy induced hepatitis mimicking viral hepatitis

Three cases of jaundice after ingestion of 3,4-methylenedioxymetamphetamine (MDMA), known as 'ecstasy', are reported and the complications associated with the misuse of this drug, which was initially misrepresented as 'safer than alcohol' are described. Ingestion of 'ecstasy' should be considered when investigating unexplained jaundice in younger patients.

The potentiation of adrenaline-induced in vitro platelet aggregation by ADP, collagen and serotonin and its inhibition by naftopidil and doxazosin in normal human subjects

1. Aggregation in platelet-rich plasma from normotensive men was induced by adrenaline (0.25-16 microM), ADP (0.25-16 microM), collagen (0.25-8 micrograms ml-1) or serotonin (10 microM) alone, or by previously sub-threshold concentrations of adrenaline (0.03-1 microM) in combination with sub-threshold concentrations of serotonin (2.5 microM), ADP (0.5 microM) or collagen (0.125 micrograms ml-1). The effects of the alpha 1-adrenoceptor blockers naftopidil and doxazosin on platelet aggregation were investigated. 2. The dose-response curves for collagen and ADP were unaffected by either drug. However, naftopidil (40 microM) inhibited serotonin-induced platelet aggregation (23.9%, 95% confidence interval (CI) 10.7 to 37.1%; P < 0.01) and caused a slight shift to the right of the adrenaline dose-response curve with a mean increase in the EC50 value of 0.5 microM (95% CI 0.07 to 0.93 microM; P < 0.05). Doxazosin had no effect on serotonin or adrenaline-induced aggregation. 3. A marked potentiation of the aggregation induced by subthreshold concentrations of adrenaline resulted from the prior addition of low concentrations of ADP, collagen or serotonin. 4. These potentiated responses were inhibited in a dose-dependent manner by naftopidil and to a lesser extent doxazosin. The maximum inhibitions (%) produced by naftopidil (40 microM) on the responses of adrenaline potentiated by ADP were 58.3% (95% CI 36.8 to 79.8%; P < 0.001), serotonin 58.9% (95% CI 40.0 to 77.8%; P < 0.001), and collagen 70.9% (95% CI 52.5 to 89.3%; P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Accumulation of 3-(phenylamino)alanine, a constituent in L-tryptophan products implicated in eosinophilia-myalgia syndrome, in blood and organs of the Lewis rats

3-(Phenylamino)alanine (PAA), a newly discovered impurity in case-associated L-tryptophan tablets, has been investigated as a possible contributing factor in the etiology of eosinophilia-myalgia syndrome (EMS). We have studied distribution and elimination of PAA in rats which were administered a single 5 mg/kg dose of PAA by gastric gavage. PAA concentrations in blood, brain, kidney and liver were measured by high-performance liquid chromatography (HPLC) with electrochemical detection. The concentration of PAA in each tissue reached a maximum at 5 h, and then gradually declined. A high level of PAA still remained at 24 h, indicating gradual elimination. The concentration of PAA in brain at 5 h was 2139 ng/g tissue, demonstrating passage through the blood-brain barrier. Consecutive administration of PAA (5 mg/kg) for 4 days resulted in approximately double the concentration in all tissues. Chronic treatment using PAA incorporated into food pellets for 6 weeks resulted in similar accumulations in each tissue, and following 12 days on a PAA free diet, levels of this drug were still detectable in all tissues.