Informing patient contacts about iatrogenic Creutzfeldt-Jakob disease

The unanticipated diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) in a patient after previous neurosurgery can lead to difficult decisions regarding informing contacts. A patient developed sCJD 3 years after neurosurgery. There were 29 potential contacts and 26 were contacted. Twelve completed a questionnaire. The majority of patients wished to know about the contact and to be seen face-to-face, and their main concern was developing the disease despite verbal and written reassurance that this was unlikely. Informing patients of sCJD contact is difficult and can lead to significant patient anxiety. Face-to-face meetings, a helpline and follow-up can help.

Guidance for the decontamination of intracavity medical devices: the report of a working group of the Healthcare Infection Society

BACKGROUND

Intracavity medical devices (ICMDs) are used in a wide variety of healthcare settings. The approach to their decontamination and the resources available also differ widely. Their potential for infection transmission is considerable.

AIM

To produce a comprehensive risk assessment-based approach to the decontamination of ICMDs, accompanied by an adaptable audit tool.

KEY RECOMMENDATIONS

Congenital abnormalities and clinical features associated with Wilms’ tumour: A comprehensive study from a centre serving a large population

Altogether 156 children treated for Wilms' tumour (WT) between 1970 and 1998 were studied. Sixty-six children, selected only by their attendance at clinic, were carefully examined and the findings compared to those from a case note review of 90 children. Congenital abnormalities were present in 45% of the examined cohort, in 19% of the case notes review group and in 30% overall. Novel findings included the association of WT with Marshall Smith syndrome, developmental delay in 3 of 4 cases of WT (one bilateral) and 1 sibling from consanguineous Pakistani families and another sibling also had leukaemia. The possibility of rare DNA repair or cancer predisposing disorders among these 4 families requires further study. Careful examination and history taking of an unselected patient cohort revealed a higher than expected incidence of clinical abnormalities which may be overlooked if not specifically sought.

Patterns of arginine and nitric oxide in patients with sickle cell disease with vaso-occlusive crisis and acute chest syndrome

PURPOSE

Our objective was to evaluate L-arginine and nitric oxide metabolite (NOx) levels in children with sickle cell disease (SCD) at steady-state and during vaso-occlusive crisis (VOC). Because alterations in nitric oxide production may have an important role in the pathophysiology of SCD, our second aim was to determine if a relationship exists between these levels and vaso-occlusive crisis (VOC).

PATIENTS AND METHODS

Plasma L-arginine and serum NOx levels were examined in 36 patients with SCD with 39 episodes of VOC and 10 children with SCD at steady-state. Daily levels were obtained in children requiring hospitalization.

RESULTS

Steady-state L-arginine levels were normal in children with SCD. L-arginine levels were low, however, in children with VOC (37.4 +/- 2.7 vs. 53.6 +/- 4.6 micromol/L; P = 0.008) but returned to baseline during hospitalization. In contrast, NOx levels were normal at presentation but decreased during hospitalization for both patients with VOC and patients with acute chest syndrome (ACS) (21.1 +/- 2.0, 17.4 +/- 2.4, and 12.3 +/- 1.6 micromol/L, respectively; P < 0.05). In the patients with VOC who had ACS develop, L-arginine decreased to the lowest levels at the time of the ACS diagnosis, correlating with decreasing NOx levels.

CONCLUSION

These data suggest that there may be a relationship between the L-arginine-nitric oxide pathway and vaso-occlusion in SCD. Low arginine levels during VOC could reflect a state of acute substrate depletion that results in a decrease in nitric oxide production.

Arginine therapy: a novel strategy to induce nitric oxide production in sickle cell disease

To determine the effects of L-arginine (L-Arg) supplementation on nitric oxide metabolite (NOx) production, oral L-Arg was given to normal controls, sickle cell disease (SCD) patients at steady state and SCD patients hospitalized with a vaso-occlusive crisis (VOC). L-Arg (0.1 g/kg) increased NOx formation by 18.8 +/- 68% in normal controls, whereas steady-state SCD patients demonstrated a paradoxical decrease in NOx of -16.7 +/- 4% (P = 0.004). In contrast, patients with VOC demonstrated a dramatic increase in NOx production by +77.7 +/- 103%, a response that was dose dependent. L-Arg appears to be the rate-limiting step in NOx production during VOC. Oral arginine may therefore benefit SCD patients by inducing an increase in NO production during VOC.

Human eotaxin induces eosinophil extravasation through rat mesenteric venules: role of alpha4 integrins and vascular cell adhesion molecule-1

Eotaxin is a potent eosinophil-specific CC-chemokine, which has been shown to play a role in the selective induction of eosinophil accumulation in a number of allergic models of inflammation. Many aspects of the mechanism by which eotaxin induces eosinophil accumulation in vivo remain unresolved. In the present study, we investigated the direct effect of synthetic human eotaxin on leucocyte/endothelial cell interactions within rat mesenteric venules, as quantified by intravital microscopy. Topical eotaxin (30 pmol) induced rapid firm adhesion and extravasation of leucocytes within the rat mesentery, the extravasated leucocytes all being eosinophils, as determined by histological analysis. Whilst eotaxin was unable to stimulate the interaction of rat eosinophils with vascular cell adhesion molecule-1 (VCAM-1) under static conditions in vitro, eotaxin-induced responses in vivo were significantly suppressed by anti-alpha4 integrin and anti-VCAM-1 monoclonal antibodies (mAbs). The anti-alpha4 integrin mAb, HP2/1 (3.5 mg/kg), inhibited the eotaxin-induced firm adhesion and extravasation, 60 min postapplication of the chemokine, by 89% and 84%, respectively. In the same set of experiments, the anti-VCAM-1 mAb, 5F10 (3.5 mg/kg), inhibited leucocyte adhesion and extravasation by 61% and 63%, respectively. These results demonstrate that eotaxin-induced migration of eosinophils through rat mesenteric venules in vivo is dependent on an alpha4 integrin/VCAM-1 adhesion pathway, the significance of which may only be evident under flow conditions and/or following the ligation of other adhesion molecules expressed on eosinophils.

Regulation of the third member of the uncoupling protein family, UCP3, by cold and thyroid hormone

Uncoupling protein (UCP1) is a transmembrane proton transporter present in the mitochondria of brown adipose tissue (BAT), a specialized tissue which functions in temperature homeostasis and energy balance (Nicholls, D. G., and Locke, R. M. (1984) Physiol. Rev. 64, 2-40; Lowell, D. D., and Flier, J. S. (1997) Annu. Rev. Med.). UCP1 mediates the thermogenesis that is characteristic of BAT by uncoupling mitochondrial oxidation of substrates from ATP synthesis. Recently, two proteins related to UCP1 have been identified and designated UCP2 (Fleury, C., et al. (1997) Nature Genetics 15, 269-272) or UCP homolog (UCPH) (Gimeno, R. E., et al. (1997) Diabetes 46, 900-906) and UCP3 (Boss, O., et al. (1997) FEBS Lett. 408, 39-42; Vidal-Puig, A., et al. (1997) Biochem. Biophys. Res. Commun. 235, 79-82). We investigated the regulation in rats of UCP3, which is expressed primarily in skeletal muscle and BAT. Expression of rat UCP3 mRNA in BAT was upregulated by in vivo treatment with triiodothyronine (T3) and by exposure to cold, suggesting that UCP3 is active in thermogenesis and energy expenditure. In skeletal muscle, UCP3 mRNA was also upregulated by T3 but, surprisingly, not by cold exposure. A hypothesis is proposed to account for this differential regulation.

Nitric oxide synthase activity is elevated in inflammatory lung disease in humans

We have characterised nitric oxide (NO) synthase activity in lung samples from patients with inflammatory lung disease compared to that in normal donor lung. NO synthase activity was measured by the ability of tissue homogenates to convert L-arginine to L-citrulline. Higher levels of NO synthase activity were found in samples from patients with inflammatory lung disease (mild asthma, cystic fibrosis, obliterative bronchiolitis after lung transplantation) compared to samples from healthy donors. NO synthase activity in all samples was mainly dependent on the presence of extracellular Ca2+. The increased NO synthase activity in diseased-lung samples suggests a modulatory role for nitric oxide in lung inflammation.

RAR beta isoforms: distinct transcriptional control by retinoic acid and specific spatial patterns of promoter activity during mouse embryonic development

That both deficiency and excess of vitamin A lead to a wide spectrum of congenital abnormalities has strongly implicated the active metabolite, retinoic acid (RA), in normal embryonic development. There are 3 families of RA receptors (RARs), RAR alpha, RAR beta and RAR gamma, each having at least two isoforms derived from primary transcripts initiated at two promoters P1 and P2 (reviewed in Leid et al., 1992) Transcripts encoding all 4 isoforms of RAR beta (RAR beta 1 to RAR beta 4) accumulate in embryonal carcinoma (EC) cells in the presence of RA. It has been previously shown that the RA modulation of RAR beta 2/beta 4 transcripts is achieved at the level of transcriptional initiation via a RA response element (RARE) present in the P2 RAR beta 2/beta 4 promoter. In contrast, the mechanism by which RA up-regulates RAR beta 1/beta 3 transcripts has not yet been elucidated. We describe here the isolation of the P1 RAR beta 1/beta 3 promoter and characterization of its activity in transgenic animals. We find that RAR beta 1/beta 3 promoter activity, which is apparently confined to the embryonic CNS, is not modified by RA treatment, unlike that of the RAR beta 2/beta 4 promoter (Mendelsohn et al., 1991). Nuclear run-on transcription analysis in EC cells supports the conclusion that RAR beta 1/beta 3 transcript initiation is not modulated by RA, and that the RA-induced accumulation of RAR beta 1/beta 3 transcripts occur via a RA-dependent release of a block in RNA chain elongation.

Human papillomavirus 6, 11, and 16 in laryngeal papillomas

Twenty-seven cases of benign laryngeal papillomas, both single and multiple variants, were analysed for human papillomavirus (HPV) by DNA slot-blot hybridization chiefly to determine the pattern of infection in Hong Kong Chinese. DNA was extracted from paraffin blocks of formalin-fixed tissue and probed separately for HPV 6, 11, 16, and 18. Sixteen cases (59 per cent) showed the presence of at least one of these four HPV genomes. Thirteen cases (48 per cent) were positive for HPV 11 only. Three other cases (11 per cent) showed triple positivity for HPV 6, 11, and 16. None were positive for HPV 18. The predominance of HPV 11 infection contrasts with other series which have shown either an almost equal distribution of HPV 6 and 11 or a predominance of HPV 6. The finding of HPV 16 in three cases was unexpected. Using the polymerase chain reaction (PCR) with primers complementary to the upstream regulatory region of the HPV 16 viral DNA, the presence of HPV 16 genome was confirmed in all three cases. As the number of HPV 16-positive cases in this study is small, analysis of more cases using fresh biopsy material and a wider range of HPV type-specific PCR primers is warranted to determine the relative incidence of HPV subtypes in these benign laryngeal papillomas.

Interaction of neuropeptide Y and the sympathetic nervous system in vascular control in man

BACKGROUND

There is increasing evidence that neuropeptide Y (NPY) contributes to the autonomic control of the circulation. NPY coexists with noradrenaline in perivascular nerve terminals, may be released during sympathetic stimulation, and is a potent constrictor of the human coronary circulation and other vascular beds. In vitro studies show that NPY can act either directly on vascular smooth muscle or indirectly by modulation of the presynaptic release or the postsynaptic actions of noradrenaline. It is unclear to what extent these mechanisms operate in vivo.

METHODS AND RESULTS

The effect on forearm blood flow of intra-arterial NPY was studied in six volunteers during coinfusion of noradrenaline and during reflex sympathetic stimulation induced by lower-body negative pressure. NPY alone induced a dose-dependent reduction of forearm blood flow in all subjects studied, to a maximum of 49 +/- 6.1%. The reduction of flow during infusion of noradrenaline alone was 42 +/- 8%. The response to noradrenaline was unaffected by coinfusion of a threshold constrictor dose of NPY (50 pmol/min). Furthermore, the reflex sympathetic vasoconstrictor response to 20 cm H2O of lower-body negative pressure was similar in both the infused and control arms during the infusion of 50 pmol/min NPY. The response to noradrenaline was abolished by alpha-blockade with phentolamine, but the flow reduction induced by NPY was unaffected by alpha-blockade.

CONCLUSIONS

NPY is a potent constrictor of human forearm resistance vessels and has a direct effect independent of alpha-receptors. NPY has no detectable modulating effect in vivo on the action of endogenous or infused noradrenaline.

Long-term therapy with benazepril in patients with congestive heart failure: effects on clinical status and exercise tolerance

Benazepril hydrochloride (CGS 14824A) is an orally active, nonsulfhydryl compound that is transformed in vivo to a long-acting inhibitor of angiotensin-converting enzyme (ACE). Previous studies have shown benazepril to lower blood pressure in hypertensive patients and to confer acute hemodynamic benefits in patients with congestive heart failure (CHF). In the current multicenter investigation, 16 patients with chronic CHF due to left ventricular systolic dysfunction (ejection fraction less than 0.40 at rest) whose symptoms corresponded to New York Heart Association classes II to IV were given open-label benazepril once daily in ascending doses of 2 to 20 mg and followed biweekly for 12 weeks. Evaluation of the 15 subjects who completed the trial showed a progressive increase in treadmill exercise duration (from 7.65 +/- 3.64 [SD] minutes at baseline to 9.74 +/- 3.66 minutes at 12 weeks, P less than .001); augmentation of the mean left ventricular ejection fraction (from 0.266 +/- 0.133 at baseline to 0.292 +/- 0.136 at 12 weeks, P less than .025); relief of exertional dyspnea in 7 of the 15 patients (P less than .02); and improvement in global symptomatic status in 10 of the patients (P less than .01). These responses were accompanied by a reduction in serum ACE activity of 75% (from 27.2 +/- 10.5 IU/L at baseline to 6.7 +/- 1.9 IU/L at 12 weeks, P less than .001), which was independent of dose and duration of treatment. The magnitude of ACE inhibition did not correlate with changes in the efficacy variables. Aside from two instances of symptomatic hypotension (one of which was complicated by volume depletion), the drug was well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterisation of tissue-specific trans-acting factor binding to a proximal element in the rat growth hormone gene promoter

Using an exonuclease III protection assay, tissue-specific binding of rat pituitary tumour cell (GH3 cell) nuclear factors to a proximal region (-68 to -138) of the rat growth hormone gene promoter has been detected. The binding is particularly strong between the borders -68 to -102. The binding is eliminated in the presence of excess unlabelled rat growth hormone gene promoter sequences but also by proximal (-423 to +38) or distal (-1960 to -1260) rat prolactin gene promoter sequences and simian virus 40 enhancer/promoter sequences. Extracts of rat pituitaries showed identical binding characteristics. Methylation interference analysis indicated that the contact points between the pituitary-specific factor and the proximal rat growth hormone gene promoter-binding element (-65 to -95) are over a conserved sequence which occurs twice in the rat growth hormone gene promoter and at least eight times in the rat prolactin gene 5'-flanking sequences. This sequence has previously been proposed to constitute the binding site for the somatotroph/lactotroph tissue-specific transcription factor. Gel-retardation and exonuclease III competition analysis showed that three of the rat prolactin gene promoter elements (-46 to -71, -156 to -180 and -174 to -204) share the ability to bind the pituitary-specific factor. The binding to the most proximal rat prolactin gene promoter element (-46 to -71) was clearly more avid than to the rat growth hormone gene promoter (-65 to -95) proximal element. However, both these elements displayed the formation of two gel-retarded complexes while the more distal rat prolactin gene binding elements (-156 to -180 and -174 to -204) formed only the smaller of the two complexes. Finally, we demonstrated by co-transfection competition analysis that plasmids containing the most proximal rat prolactin gene promoter binding element completely inhibited transcription from the rat growth hormone gene promoter while rat growth hormone gene promoter sequences only partially inhibited transcription from the rat prolactin gene promoter. This suggests that the higher affinity for factor binding displayed by the proximal rat prolactin gene promoter binding site in vitro is reflected in factor binding activity in vivo.

Vasodilatation by calcitonin gene-related peptide and by substance P: a comparison of their effects on resistance and capacitance vessels of human forearms

A comparison has been made of the effects of the potent vasodilating peptide calcitonin gene-related peptide (CGRP) and substance P (SP) on resistance and capacitance vessels of normal subjects. Brachial artery infusion of 1.25 to 10 pmol/min CGRP and of 0.25 to 1.5 pmol/min SP produced maximal increases in forearm blood flow (177 +/- 75% and 198 +/- 50%, respectively), as measured by venous occlusion plethysmography. The vasodilation due to CGRP was prolonged, with a half-life of biological effect of approximately 18 min, while that due to SP was of short duration, with a half-life of biological effect of approximately 15 sec. There was rapid development of tachyphylaxis to the effects of arterial infusion of SP, but not of CGRP, during a prolonged infusion at one dose. CGRP did not alter the diameter of a superficial hand vein, either at rest or when the vein was constricted by a simultaneous infusion of norepinephrine or by the single deep breath reflex. In contrast, SP caused dilatation of veins preconstricted with norepinephrine, although the effect was only transient and dose-response curves could not be constructed. The venoconstrictor response to a single deep breath was abolished by SP. Simultaneous arterial infusion of both peptides produced at least additive, and possibly synergistic, effects on forearm blood flow. We propose that both CGRP and SP have a role in the regulation of vascular smooth muscle tone.

Coronary artery infusion of neuropeptide Y in patients with angina pectoris

Neuropeptide Y was infused into a coronary artery of 6 patients with typical angina but no significant coronary stenosis. 3 patients had transient myocardial ischaemia, shown by typical pain and electrocardiographic change, at doses of 0.2 pmol/kg per min in 2 patients and 1.0 pmol/kg per min in 1 patient. The arteriographic appearances suggested constriction of small vessels rather than constriction of epicardial coronary arteries. The ischaemia was completely reversed by intracoronary administration of isosorbide dinitrate with no adverse sequelae. This is the first demonstration of myocardial ischaemia in man induced by a peptide neurotransmitter.

Induction of coronary artery spasm by a direct local action of ergonovine

To investigate whether ergonovine acts directly on coronary arteries or via remote neurohumoral reflexes, we administered small titrated increments of intracoronary ergonovine up to a maximum cumulative dose of 50 micrograms to 15 patients. In six patients with variant angina (group 1), ischemic electrocardiographic ST changes, angina, and localized coronary spasm (local coronary diameter reduction of 87.8 +/- 18.9% [mean +/- SD]) followed after 6 to 50 micrograms (mean 20.7) cumulative intracoronary ergonovine. In nine patients with atypical chest pain, normal baseline coronary arteriograms, and no evidence of variant angina (group 2), there was no ischemic ST segment change or localized coronary spasm after 6 to 50 micrograms (mean 31.6) intracoronary ergonovine. Coronary diameter of proximal vessels of patients in group 2 was reduced by 16.2 +/- 6.5% and did not differ from the response of nonspastic vessels of comparable size of group 1 (20.5 +/- 13.8%; p = .7). There was no significant difference in the median effective dose values in the dose-response curves of the spastic and nonspastic segments between groups 1 and 2. Ergonovine causes coronary spasm by a direct local effect, which seems to be caused by localized arterial hyperreactivity rather than supersensitivity. Intracoronary delivery may be safer than intravenous administration because negligible drug recirculation may prevent perpetuation of spasm and selective coronary administration can avoid branches with critical stenoses.

Feasibility study of a statewide pathology-based cancer surveillance system in Minnesota. I. Information characteristics

The Minnesota Department of Health has completed a 2-year feasibility study comparing the completeness and accuracy of information from pathology-based cancer ascertainment with that of the traditional surveillance method based on hospital discharge records. Overall, for incident cancers, the primary site designation of the pathology-based system was correct for 94.5% of the cancers, and the histologic designation was correct for 97.0% of the cancers. For prevalent cancers the accuracy of both site and histology designation was inadequate at 81.0 and 76.8% respectively. Pathology-based ascertainment was more complete than discharge-based surveillance (98.4% vs. 96.6%), which reflected the growing number of cancers diagnosed in hospital outpatient departments and medical clinics. The major limitation of the pathology-based system was the inability to determine from written pathology reports whether the cancer was newly diagnosed. However, when asked, pathologists correctly determined the incidence status for approximately 75% of the cancers. In light of the results of the feasibility study, Minnesota is implementing a pathology-based system as a cost-effective, scientifically valid method to meet the state's current and future needs for cancer surveillance.

Calcitonin gene-related peptide: a potent dilator of human epicardial coronary arteries

To investigate the action of calcitonin gene-related peptide (CGRP) on human epicardial coronary arteries, six patients received intracoronary CGRP at doses of 50,100, and 200 ng/min. The effect of CGRP was measured angiographically with a computerized analysis system. A dose-dependent increase in coronary arterial diameter was observed. At the highest dose there were 34%, 7%, 38%, and 40% mean increases in the diameters of the circumflex, proximal, mid, and distal left anterior descending arteries, respectively. No further increase in diameter was found after a subsequent dose of 1 mg intracoronary isosorbide dinitrate. Prior infusion of CGRP did not prevent coronary arterial spasm induced by ergonovine in two patients with variant angina, but a subsequent bolus of CGRP partially relieved the spasm. We propose that CGRP has a role in the regulation of coronary vascular smooth muscle tone.