Rapid and reversible humidity-dependent colour change by water film formation in a scaled springtail

Colour is often not a static trait but can change over time either through biotic or abiotic factors. Humidity-dependent colour change can occur through either morphological change (e.g. to feather barbules in birds) or by the replacement of air by water causing a shift in refractive index, as seen in arthropod multi-layer cuticles or scales. The scaled springtail Lepidocyrtus cyaneus has scales that produce colour largely via thin film interference from their lamina. We observed a marked colour change from golden to violet/purple coloration in humid conditions. Light microscopy, micro-spectrophotometry, contact angle goniometry and optical modelling indicate that the formation of a thin film of water on top of the hydrophilic scales increases their laminar thin film thickness, causing a shift towards violet/purple colour. Evaporation of the water film causes the metallic golden colour to return. This constitutes a remarkably rapid colour change (in the order of seconds), only limited by the speed of water film condensation and evaporation, that may serve as inspiration for new dynamically coloured materials and sensors.

An updated checklist of Collembola in Taiwan, with DNA barcoding of Papirioidesjacobsoni Folsom, 1924 (Symphypleona, Dicyrtomidae)

From urban green space to pristine forest, Collembola is one of the most numerous and species-rich members of the soil fauna around the world. However, due to lack of taxonomic expertise and research, its diversity is poorly understood, especially in tropical and subtropical regions. Collembola biodiversity studies in Taiwan have not seen much progress since 1981, when Hsin Chi reviewed 26 species belonging to 20 genera and eight families. Additionally, reports of new records in Taiwan in the last 40 years are scattered amongst several publications and not easily accessible to most end-users. Thus, a concise summary of related research is urgently needed. In this study, we updated the checklist of Collembola in Taiwan, based on published papers as well as images recorded in 2020-2022. We concluded that 58 species of Collembola belonging to 31 genera and 12 families have been reported in Taiwan, including 13 newly-recorded species. This species richness marks a 123% increase from the 1981 review. The results have been made publicly available in the Catalog of Life in Taiwan database and the images recorded have been used to update species information in collembola.org. We also characterised morphological and genetic variations in the globular springtail species Papirioidesjacobsoni Folsom, 1924 using DNA barcodes and highlighted potential research directions.

Springtail coloration at a finer scale: mechanisms behind vibrant collembolan metallic colours

The mechanisms and evolution of metallic structural colours are of both fundamental and applied interest, yet most work in arthropods has focused on derived butterflies and beetles with distinct hues. In particular, basal hexapods-groups with many scaled, metallic representatives-are currently poorly studied and controversial, with some recent studies suggesting either that thin-film (lamina thickness) or diffraction grating (longitudinal ridges, cross-ribs) elements produce these colours in early Lepidoptera and one springtail (Collembola) species. Especially the collembolan basal scale design, consisting of a single lamina and longitudinal ridges with smooth valleys lacking cross-ribs, makes them an interesting group to explore the mechanisms of metallic coloration. Using microspectroscopy, Raman spectroscopy, electron microscopy and finite-difference time-domain optical modelling, we investigated scale colour in seven springtail species that show clear metallic coloration. Reflectance spectra are largely uniform and exhibit a broadband metallic/golden coloration with peaks in the violet/blue region. Our simulations confirm the role of the longitudinal ridges, working in conjunction with thin-film effects to produce a broadband metallic coloration. Broadband coloration occurs through spatial colour mixing, which probably results from nanoscale variation in scale thickness and ridge height and distance. These results provide crucial insights into the colour production mechanisms in a basal scale design and highlight the need for further investigation of scaled, basal arthropods.

Stopping nucleos(t)ide analogue treatment in Caucasian hepatitis B patients after HBeAg seroconversion is associated with high relapse rates and fatal outcomes

BACKGROUND

Stopping nucleos(t)ide analogues (NA) after hepatitis B e antigen (HBeAg) seroconversion is associated with high relapse rates in Asian patients, but data in Caucasian cohorts are scarce. Clinical course, outcomes and immunological aspects of chronic hepatitis B infections differ substantially between distinct ethnicities.

AIM

The aim of this study was to determine relapse rates, factors predicting relapse and clinical outcomes after nucleos(t)ide analogue cessation in a large, predominantly Caucasian cohort of chronic hepatitis B patients with nucleos(t)ide analogue-induced HBeAg seroconversion.

METHODS

This is a nationwide observational cohort study including HBeAg positive, mono-infected chronic hepatitis B patients with nucleos(t)ide analogue-induced HBeAg seroconversion from 18 centres in Belgium.

RESULTS

A total of 98 patients with nucleo(s)tide analogue-induced HBeAg seroconversion were included in the study. Of the 62 patients who stopped treatment after a median consolidation treatment of 8 months, 30 relapsed. Higher gamma-glutamyl transferase levels at both treatment initiation (HR 1.004; P = 0.001 per unit increment) and HBeAg seroconversion (HR 1.006; P = 0.013 per unit increment) were associated with an increased risk of clinically significant relapse in a multivariate Cox regression model. Treatment cessation led to liver-related death in 2 patients, of whom one showed a severe flare. Of the patients who continued treatment after HBeAg seroconversion, none relapsed or developed severe hepatic outcomes.

CONCLUSION

Treatment withdrawal in Caucasian chronic hepatitis B patients after nucleos(t)ide analogue-induced HBeAg seroconversion results in viral relapses in more than half of patients with potential fatal outcomes. These real-world data further lend support to preferentially continue NA treatment after HBeAg seroconversion until HBsAg loss.

Hepatic schistosomiasis with massive splenomegaly: a case report and literature review

Schistosomiasis is a parasitic disease caused by Schistosoma species. Intestinal and hepatic schistosomiases are the most common forms of chronic disease. We describe a case of a 26-year old patient from Eritrea who was referred to our hospital with abdominal pain and diarrhea. The diagnosis of hepatosplenic schistosomiasis was made by liver biopsy and the patient was treated with praziquantel. Hepatic schistosomiasis is characterised by deposition of schistosomal eggs in the liver which results in a host cell immune response and leads to granuloma formation and neoangiogenesis. This is hallmarked by different grades of periportal fibrosis with portal hypertension leading to splenomegaly. Normal liver architecture is preserved and periportal fibrosis can be reversible if treated adequately and timely. With a recent native schistosomiasis cluster report from France and the expected influx to Europe of persons from regions endemic for schistosomiasis, increased awareness of this disease in healthcare practitioners is needed. We review the epidemiology, pathogenesis, clinical presentation and treatment of schistosomiasis.

[Prolapse and urinary incontinence in women : place of the general practitioner]

The ageing of the population, having access to good quality of care, will result in an increase in the prevalence of pelvic floor diseases. Those persons, often in good general health, may experience difficulties in accepting functional pathologies, associated with loss in quality of life. One out of 2 women will have a pelvic floor problem and 1 out of 9 will have a surgical perineal procedure before the age of 80 years. The unitary character of the pelvic floor, a complex functional anatomic region, is often forgotten, essentially because the patients complain about one main pathology like urinary incontinence, genital prolapse, constipation and sexual disorders or chronic pain and will consult one specific specialist. Our role as health care professionals is to be aware of those associated pathologies and to obtain an optimal quality of care. The actual evolution towards specific clinical pathways with the integration of office provided care outside the hospital, needs to become the new standard of care. We try to give an overview of the different preventive, diagnostic and therapeutic options, available in a general practitioner's office. Taking care of the pelvic floor needs to be done in a global and pluridisciplinar setting. Referring towards specialised centres as well as the integration of the general practitioner, especially for the more complex cases, is essential.

The risk of early occurrence and recurrence of hepatocellular carcinoma in hepatitis C-infected patients treated with direct-acting antivirals with and without pegylated interferon: A Belgian experience

Recently, concerns were raised of high rates of HCC recurrence in patients treated with direct-acting antivirals (DAA) for hepatitis C infection. We investigated the HCC occurrence and recurrence rates within 6 months after treatment with DAA with or without pegylated interferon (PEG-IFN) in real life. This is a retrospective, multicenter cohort trial, executed in 15 hospitals distributed across Belgium. Populations were matched based on fibrosis score (Metavir F3-F4). Patients with a Child-Pugh score ≥ B were excluded. In total, 567 patients were included, of whom 77 were treated with PEG-IFN+DAA between 2008 and 2013 and 490 with DAA without PEG-IFN between 2013 and 2015. Patients treated with PEG-IFN+DAA (53±9y) were younger than patients treated with DAA without PEG-IFN (59±12y) (P=.001). 47% of patients treated with PEG-IFN+DAA were in the F4 stage vs 67% of patients treated with DAA without PEG-IFN (P=.001). Screening was inadequate in 20% of both patient groups (P=.664). The early occurrence rate of HCC was 1.7% and 1.1% in patients treated with DAA with and without PEG-IFN, respectively (P=.540). The early recurrence rate was 0% in patients treated with PEG-IFN+DAA and 15.0% in patients treated with DAA without PEG-IFN (P=.857). There is no difference in early occurrence of new HCC between patients treated with DAA with and without PEG-IFN. We did observe a high early recurrence rate of HCC in patients treated with DAA without PEG-IFN. However, these patients were at baseline more at risk for HCC. Finally, in 20%, screening for HCC was inadequate.

Thoracic aortic aneurysm complicated by secondary aortoesophageal fistula after thoracic endovascular aortic repair : a case report

This is a case report of a patient with a thoracic aortic aneurysm (TAA) presenting with dysphagia and weight loss as primary symptoms. She was treated via thoracic endovascular aortic repair (TEVAR). The procedure was complicated with a secondary aortoesophageal fistula (AEF) for which open surgical repair of the esophageal defect was done. Long term (i.e. more than 30 days) antibiotics were given. The recovery was uneventful.

Dual Alleviation of Acute and Neuropathic Pain by Fused Opioid Agonist-Neurokinin 1 Antagonist Peptidomimetics

Herein, the synthesis and biological evaluation of dual opioid agonists-neurokinin 1 receptor (NK1R) antagonists is described. In these multitarget ligands, the two pharmacophores do not overlap, and this allowed maintaining high NK1R affinity and antagonist potency in compounds 12 and 13. Although the fusion of the two ligands resulted in slightly diminished opioid agonism at the μ- and δ-opioid receptors (MOR and DOR, respectively), as compared to the opioid parent peptide, balanced MOR/DOR activities were obtained. Compared to morphine, compounds 12 and 13 produced more potent antinociceptive effects in both acute (tail-flick) and neuropathic pain models (von Frey and cold plate). Similarly to morphine, analgesic tolerance developed after repetitive administration of these compounds. To our delight, compound 12 did not produce cross-tolerance with morphine and high antihyperalgesic and antiallodynic effects could be reinstated after chronic administration of each of the two compounds.

Belgian experience with triple therapy with boceprevir and telaprevir in genotype 1 infected patients who inject drugs

No data have been reported yet on treatment outcome in persons who inject drugs (PWID) infected with hepatitis C virus treated with boceprevir or telaprevir in combination with peginterferon (Peg IFN) and ribavirin (RBV). Additionally, there are concerns about the safety of boceprevir and telaprevir in some subgroups of patients with hepatitis C (HCV). In a cohort of HCV patients infected with genotype 1 in Belgium, treatment outcome of patients infected due to IV drug use was analyzed and compared with patients who have no history of substance use. The study population consisted of 179 patients: 78 PWID and 101 controls treated with boceprevir (n = 79) or telaprevir (n = 100) additional to Peg IFN and RBV; 53 (30%) had advanced disease (F3, F4) and 79 (44%) had an antiviral therapy previously. There were no significant differences in the baseline characteristics between both groups, except that PWID patients were more frequently infected with genotype 1a (67% vs 21%), were younger and were predominantly male. Psychiatric complaints during follow-up occurred more frequently in the PWID patients: 24% versus 11% (P = .02). Treatment failure for other reasons than absence of viral response was 70% and 64% in PWID and non-PWID respectively. The sustained viral response (SVR) rates were similar in both groups (71% in PWID vs 72% in non-PWID); with a non-inferiority test with -5% margin there is a difference of -1% (95% CI [-15%, 13%]) and P = 0.30. There are no reasons to exclude PWID from treatment with boceprevir, telaprevir and novel antiviral therapies.

Experimental studies to improve the reliability and validity of regulatory judgments on health care in the Netherlands: a randomized controlled trial and before and after case study

RATIONALE, AIMS AND OBJECTIVES

We examined the effect of two interventions on both the reliability and validity of regulatory judgments: adjusting the regulatory instrument and attending a consensus meeting.

METHOD

We adjusted the regulatory instrument. With a randomized controlled trial (RCT) we examined the effect of the adjustments we made to the instrument. In the consensus meeting inspectors discussed cases and had to reach consensus about the order of the cases. We used a before and after case study to assess the effect of the consensus meeting. We compared the judgments assigned in the RCT with the unadjusted instrument with the judgments assigned with the unadjusted instrument after the consensus meeting. Moreover we explored the effect of increasing the number of inspectors per regulatory visit based on the estimates of the two interventions.

RESULTS

The consensus meeting improved the agreement between inspectors; the variance between inspectors was smallest (0.03) and the reliability coefficient was highest (0.59). Validity is assessed by examining the relation between the assigned judgments and the corporate standard and expressed by a correlation coefficient. This coefficient was highest after the consensus meeting (0.48). Adjustment of the instrument did not increase reliability and validity coefficients.

CONCLUSIONS

Participating in a consensus meeting improved reliability and validity. Increasing the number of inspectors resulted in both higher reliability and validity values. Organizing consensus meetings and increasing the number of inspectors per regulatory visit seem to be valuable interventions for improving regulatory judgments.

Reducing interrater variability and improving health care: a meta-analytical review

OBJECTIVES

In the scientific literature about reliability, the main approach to increasing reliability seems to involve increasing the number of observers and improving the instrument used. Other aspects for improving reliability - like the training of raters - seem to receive less notice. It is worth asking whether this technical approach could be complemented by training the user of the instrument. A systematic meta-analytical review of the research literature was performed to answer this question and examine the effectiveness of planned interventions for improving interrater reliability of health care professionals.

METHOD

The databases of PubMed (MEDLINE), Embase, Omega and PsycINFO were searched. The inclusion criteria were met by 57 studies. Details extracted from the studies included the study design, the number of observers and the number of observed cases, the intervention, the type of instrument (whether or not it was highly technical), and statistical information about the agreement before and after the intervention. Interventions were categorized into three groups: training of professionals, improving the diagnostic instrument and a combination of training and improving the instrument. A meta-analysis was performed by means of linear regression.

RESULTS

The interventions were arranged according to their effectiveness in improving the diagnostic instrument (mean change: β = 0.13), training combined with improving the instrument (mean change: β = 0.10) and training (mean change: β = 0.09).

CONCLUSION

On average, although all types of interventions are effective, improving the diagnostic instrument seems to be the most effective. Especially when highly technical instruments were concerned, improvement proved to be very effective (β = 0.52). Because instrumental variables constitute a major source of error, improving the instrument is an important approach. However, this review offers solid arguments that can complement the literature and practice, with a focus on training the user of the instrument.

Hepatic amyloidosis increases liver stiffness measured by transient elastography

Liver stiffness values in transient elastography (TE) have to be interpreted with caution. Steatosis, congestion, acute inflammation and extrahepatic cholestasis can indeed influence measurements. Obtained stiffness values in the cirrhotic range can also be present in the absence of fibrosis as in hepatic amyloidosis. Here we report two cases of systemic amyloidosis with hepatic involvement where high stiffness values were measured at TE. In fact, deposits of amyloid may increase the rigidity of the liver parenchyma resulting in higher liver stiffness values. Therefore, results of TE should always be interpreted in their clinical context and if inconsistent, the performance of a liver biopsy might be necessary.

Selection of a respiratory syncytial virus fusion inhibitor clinical candidate, part 1: improving the pharmacokinetic profile using the structure-property relationship

We previously reported the discovery of substituted benzimidazole fusion inhibitors with nanomolar activity against respiratory syncytial virus (Andries, K.; et al. Antiviral Res. 2003, 60, 209-219). A lead compound of the series was selected for preclinical evaluation. This drug candidate, JNJ-2408068 (formerly R170591, 1), showed long tissue retention times in several species (rat, dog, and monkey), creating cause for concern. We herein describe the optimization program to develop compounds with improved properties in terms of tissue retention. We have identified the aminoethyl-piperidine moiety as being responsible for the long tissue retention time of 1. We have investigated the replacement or the modification of this group, and we suggest that the pKa of this part of the molecules influences both the antiviral activity and the pharmacokinetic profile. We were able to identify new respiratory syncytial virus inhibitors with shorter half-lives in lung tissue.

Norpiperidine Imidazoazepines as a New Class of Potent, Selective, and Nonsedative H1 Antihistamines

Clinical doses of available H(1) antihistamines are limited mainly by sedative side effects. However, higher doses are often required to obtain optimal therapeutic activity, especially in dermatology. We report the synthesis of three norpiperidine imidazoazepines representative of a new class of selective and nonsedating H(1) antihistamines. The compounds were at least as potent as cetirizine and loratadine as measured by H(1) receptor binding affinity, by protection against compound 48/80- and histamine-induced lethality in rats and guinea pigs, respectively, and by skin reaction tests in rats, guinea pigs, and dogs. The compounds, in particular 3a, were less prone than the reference compounds to penetrate the brain and to occupy central H(1) receptors, suggesting absence of sedative side effects. In vitro and in vivo cardiovascular safety tests showed that 3a had no intrinsic potential to prolong ventricular repolarization or induce cardiac arrhythmias. Compound 3a has been selected for further clinical development, mainly for application in dermatology.

Ureteral ectopy in the seminal vesicle associated with cyst formation and renal dysplasia: contribution of 3D-MRI

A case of a congenital anomaly of the urinary tract in a 25-year-old Caucasian male is presented. Preoperative and pathologic findings demonstrated an ectopic ureter which terminated in a seminal vesicle cyst. Both structures formed an abortive common duct at the bladder base. The ipsilateral kidney was dysplastic. Findings on voiding cytourethrography, spiral CT, and MRI are discussed and correlated with pathologic findings. The authors suggest that MRI, especially with the use of 3D sequences, is the examination of choice in the evaluation of a complex congenital urogenital anomaly as presented.

Substituted benzimidazoles with nanomolar activity against respiratory syncytial virus

A cell-based assay was used to discover compounds inhibiting respiratory syncytial virus (RSV)-induced fusion in HeLa/M cells. A lead compound was identified and subsequent synthesis of >300 analogues led to the identification of JNJ 2408068 (R170591), a low molecular weight (MW 395) benzimidazole derivative with an EC(50) (0.16 nM) against some lab strains almost 100,000 times better than that of ribavirin (15 microM). Antiviral activity was confirmed for subgroup A and B clinical isolates of human RSV and for a bovine RSV isolate. The compound did not inhibit the growth of representative viruses from other Paramyxovirus genera, i.e. HPIV2 and Mumps Virus (genus Rubulavirus), HPIV3 (genus Respirovirus), Measles virus (genus Morbillivirus) and hMPV. Efficacy in cytopathic effect inhibition assays correlated well with efficacy in virus yield reduction assays. A concentration of 10nM reduced RSV production 1000-fold in multi-cycle experiments, irrespective of the multiplicity of infection. Time of addition studies pointed to a dual mode of action: inhibition of virus-cell fusion early in the infection cycle and inhibition of cell-cell fusion at the end of the replication cycle. Two resistant mutants were raised and shown to have single point mutations in the F-gene (S398L and D486N). JNJ 2408068 was also shown to inhibit the release of proinflammatory cytokines IL-6, IL-8 and Rantes from RSV-infected A549 cells.

Peliosis hepatis presenting as a multifocal hepatic pseudotumor: MR findings in two cases

Two cases of pseudotumoral peliosis hepatis are presented with emphasis on MRI findings. One patient had four individual lesions, the other had two. Image characteristics in both were: heterogeneic signal intensity on T1-weighted images (T1WI) with areas of high-, intermediate, and low signal intensity; heterogeneic signal intensity on T2WI with presence of numerous intralesional "cystic" hyperintense areas with a hypointense border. Signal intensities on T1WI were iso- to hypointense in one case and mild central hyperintensities were demonstrated in the other case, probably due to intra-lesional hemorrhage or diffuse accumulation of fresh clotting within the sinusoids. One case demonstrated early enhancement of the peripheral borders in the arterial phase, and both demonstrated enhancement in the portovenous and late phases. One case was studied with Gd-BOPTA and iron oxides and demonstrated enhancement with both products, suggestive for the presence of hepatocytes and Kupffer cells. This is the first report of the use of hepato-specific contrast agents in this entity. Spontaneous regression of the lesions was demonstrated on a follow-up MR examination in one case.

Proximal pulmonary artery aneurysm

The authors report on a case of proximal pulmonary artery aneurysm detected on a routine chest X-ray. The scintigraphic and angiographic features of the condition are described and the importance of including the entity in the differential diagnosis of lung masses is stressed.

Midgut volvulus in an adult patient

The authors report on a case of midgut volvulus in a 27-year-old man who presented with bilious vomiting and acute abdominal pain. US demonstrated a reversal of the normal relationship between the superior mesenteric artery (SMA) and superior mesenteric vein (SMV). A clockwise whirlpool sign, diagnostic for midgut volvulus, was not visualised. In a further assessment, upper gastrointestinal series demonstrated obstruction in the second part of the duodenum highly suspicious of Ladd's bands. Malpositioning of bowel structures, as already suggested by the reversal of the SMA and SMV on ultrasound, and a distinctive whirl pattern due to the bowel wrapping around the SMA was demonstrated on CT. Furthermore angiography revealed focal twisting of the SMA. US is the first imaging modality to perform in suspicion of midgut volvulus. When inconclusive, CT is in our opinion the next stage in the diagnostic work-up.

Renal macronodular tuberculoma: CT and MR findings in an asymptomatic patient

We present the case of a 50-year-old man with a solitary mass lesion in the right kidney. Characteristics on ultrasound were a thick irregular hypoechoic wall and a slightly hyperechoic center. Computed tomography depicted the lesion as spontaneously hyperdense at its base. After administration of intravenous iodinated contrast only partial enhancement in the peripheral wall was seen. On MR imaging the lesion was hypointense on T1-weighted images, and T2-weighted images demonstrated a thick irregular hypointense peripheral wall and an intralesional fluid debris level. Gadolinium-chelates were not administered.

Pharmacological profile of (2R-trans)-4-[1-[3,5-bis(trifluoromethyl)benzoyl]-2-(phenylmethyl)-4-piperidinyl]-N-(2,6-dimethylphenyl)-1-acetamide (S)-Hydroxybutanedioate (R116301), an orally and centrally active neurokinin-1 receptor antagonist

In comparison with a series of reference compounds, (2R-trans)-4-[1-[3,5-bis(trifluoromethyl)benzoyl]-2-(phenylmethyl)-4-piperidinyl]-N-(2,6-dimethylphenyl)-1-acetamide (S)-Hydroxybutanedioate (R116301) was characterized as a specific, orally, and centrally active neurokinin-1 (NK(1)) receptor antagonist with subnanomolar affinity for the human NK(1) receptor (K(i): 0.45 nM) and over 200-fold selectivity toward NK(2) and NK(3) receptors. R116301 inhibited substance P (SP)-induced peripheral effects (skin reactions and plasma extravasation in guinea pigs) and a central effect (thumping in gerbils) at low doses (0.08-0.16 mg/kg, s.c. or i.p.), reflecting its high potency as an NK(1) receptor antagonist and excellent brain disposition. Higher doses blocked various emetic stimuli in ferrets, cats, and dogs (ED(50) values: 3.2 mg/kg, s.c.; 0.72-2.5 mg/kg, p.o.). Even higher doses (11-25 mg/kg, s.c.) were required in mice (capsaicin-induced ear edema) and rats (SP-induced extravasation and salivation), consistent with lower affinity for the rodent NK(1) receptor and known species differences in NK(1) receptor interactions. R116301 inhibited the ocular discharge (0.034 mg/kg) but not the dyspnoea, lethality, or cough (>40 mg/kg, s.c.) induced by [betaALA(8)]-neurokinin A (NKA) (4-10) in guinea pigs, attesting to NK(1) over NK(2) selectivity. R116301 did not affect senktide-induced miosis (>5 mg/kg, s.c.) in rabbits, confirming the absence of an interaction with the NK(3) receptor. R116301 was inactive in guinea pigs against skin reactions induced by histamine, platelet-aggregating factor, bradykinin, or Ascaris allergens (>10 mg/kg, s.c.). In all species, R116301 showed excellent oral over parenteral activity (ratio, 0.22-2.7) and a relatively long duration (6.5-16 h, p.o.). The data attest to the specificity and sensitivity of the animal models and support a role of NK(1) receptors in various diseases.

The role of MR imaging for the assessment of complicated duplex kidneys in children: preliminary report

OBJECTIVE

To determine whether MR imaging, including MR urography, is able to assess complicated duplex kidneys and to determine the possible role of MRI compared to other imaging techniques in such uropathies.

MATERIAL AND METHODS

Twenty consecutive patients (age 1 month-11 years) presenting with a suspicion of a complicated duplex kidney were prospectively studied with MRI and MR urography. The examinations were performed on a 0.5-T machine using routinely available sequences that were optimised to the patient's age and size. MR images were reviewed separately by two observers blinded to the patient history. They were asked to assess the presence of a duplex kidney, the presence of an abnormality that may require surgery and to indicate the type of the inferior ureteric insertion. A qualitative gradation of these results was performed on the basis of the final diagnosis provided at endoscopy (n = 6) or surgery (n = 14). MR results were compared to those provided by US examinations and excretory urography, when available, and a non-parametric statistical analysis was performed.

RESULTS

MRI differentiated well between the upper and the lower poles of the kidneys and correctly answered the three questions in all 20 patients. The two observers agreed completely in all the 20 patients. MR was statistically superior to both US and excretory urography in the evaluation of the distal ureter (P < 0.05).

CONCLUSIONS

MRI provides a precise assessment of the complications associated with duplex kidneys. Its optimal role seems to be the assessment of ectopic extra-vesical ureteric insertions and whenever an occult upper pole is suspected.

Recombinant human growth hormone treatment in short children with chronic renal disease, before transplantation or with functioning renal transplants: an interim report on five European studies

Growth retardation is common in children with chronic renal disease. Final adult height is often reduced, even in children with a functioning renal transplant. The five European studies considered here aim to investigate the efficacy and safety of recombinant human growth hormone therapy (rhGH) in two groups of short children with chronic renal disease. The first group comprises 29 prepubertal children with preterminal chronic renal failure (i.e. before renal transplantation), and the second group comprises 39 prepubertal and pubertal children with functioning renal transplants. The median bone age retardation in the groups at the start of treatment was between 2.2 and 3.7 years; this did not change during the first year of treatment. This interim report concentrates on patients who have been treated for at least 1 year (i.e. 22 children from the first group, and 28 children from the transplant group (15 prepubertal and 13 pubertal children). The median height velocity increased from 4.8 cm/year to 10.0 cm/year in the first group (the chronic renal failure group), from 2.6 cm/year to 6.2 cm/year in prepubertal children with renal transplants and from 3.8 cm/year to 6.7 cm/year in pubertal children with renal transplants. The corresponding changes in height velocity SDS were from -1.3 to 5.1 for the chronic renal failure group and -2.8 to 2.3 for the prepubertal children with renal transplants. Renal function declined in the chronic renal failure group but this decline corresponded to expected progression of the disease. Some of the children with renal transplants showed a decreased renal function, which in most cases was explained by non-compliance or chronic rejection.

Synthetic 1,4-disubstituted-1,4-dihydro-5H-tetrazol-5-one derivatives of fentanyl: alfentanil (R 39209), a potent, extremely short-acting narcotic analgesic

The synthesis of a series of N-1,4-disubstituted-1,4-dihydro-5H-tetrazol-5-one piperidinyl derivatives of fentanyl, carfentanil, and sufentanil is described. The 1-substituted tetrazolinones 2 were essentially prepared via the addition reaction of aluminium azide to isocyanates or acid chlorides in tetrahydrofuran. Alkylation of 2 under neutral or weakly basic conditions afforded almost exclusively the 1,4-disubstituted tetrazolinone isomer 3. N-Alkylation of the piperidine derivatives 4 with 3 in dimethylformamide yielded 9a-v. The morphinomimetic activity in rats, after intravenous injection of the compounds, was evaluated in the tail withdrawal reflex test. The fentanyl analogues 9a-c (R4 = H) are inactive at the measured dose of 2.5 or 10 mg/kg (iv). For the carfentanil analogues (R4 = COOCH3) maximal narcotic activity is found when R1 represents a lower alkyl group (9d-f) or a thienylethyl group (9n). The sufentanil analogues (R4 = CH2OCH3) show the same structure-activity relationship (SAR) profile as the carfentanil derivatives (R4 = COOCH3). The structural requirements for optimal activity are in good agreement with earlier observations in the series of 10-12. From the series the ethyl tetrazolinone derivative 9r, alfentanil (R 39209), was selected for clinical investigation. As an analgesic in rats, 9r is 140 times more potent than pethidine 15 and 72 times more potent than morphine 14. Alftentanil reaches its peak effect within 1 min after injection, and its duration of action is very short; at 2 times its MED50, 9r has a duration of action of 11 min. This duration is 30 min for 10 and 90 min for 14. Compared to 10, alfentanil 9r is about 4 times faster but 3 times shorter acting. Structurally, 9r shows most resemblance to sufentanil 12, since it differs only by substitution of a 4-ethyltetrazolinone ring for the thiophene ring. The considerable differences in their pharmacological profiles were explained in terms of marked variations in physicochemical and, hence, pharmacokinetic properties.

New antihistaminic N-heterocyclic 4-piperidinamines. 2. Synthesis and antihistaminic activity of 1-[(4-fluorophenyl)methyl]-N-(4-piperidinyl)-1H-benzimidazol-2-a mines

The synthesis of a series of 1-[(4-fluorophenyl)methyl]-N-(4-piperidinyl)-1H-benzimidazol-2-ami nes and the preliminary evaluation of their in vivo antihistamine activity are described. The title compounds were obtained starting from either 1, 4, 10, or 55 by different synthetic methods. Substitution on the phenyl nucleus of the benzimidazole ring (84-87) was achieved by two different approaches. The in vivo antihistamine activity was evaluated by the compound 48/80 induced lethality test in rats and the antihistamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. The duration of action was studied in the guinea pig for three compounds (4, 51, and 55). Compound 51, "astemizole", was also studied in histamine- and serotonin-induced cutaneous reaction and for mydriatic activity in the rat and tested for peripheral and central effects not related to histamine antagonism in a variety of systems. Astemizole has been selected for clinical investigation.

New antihistaminic N-heterocyclic 4-piperidinamines. 3. Synthesis and antihistaminic activity of N-(4-piperidinyl)-3H-imidazo[4,5-b]pyridin-2-amines

To study the bioisosteric replacement of a 2-pyridyl ring for a phenyl nucleus in astemizole, a series of N-(4-piperidinyl)-3H-imidazo[4,5-b]pyridin-2-amines was synthesized and evaluated. The title compounds were obtained starting from either 8a or 8b by four synthetic methods. The in vivo antihistamine activity was evaluated by the compound 48/80-induced lethality test in rats and the histamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. Compound 37, the isostere of astemizole, showed the most potent antihistaminic properties in the rat. However, astemizole is superior to 37 as to duration of action and total potency.

New antihistaminic N-heterocyclic 4-piperidinamines. 1. Synthesis and antihistaminic activity of N-(4-piperidinyl)-1H-benzimidazol-2-amines

The synthesis of a series N-(4-piperidinyl)-1H-benzimidazol-2-amines and the preliminary evaluation of their in vitro and in vivo antihistaminic activity are described. Cyclodesulfurization of (2-aminophenyl)thioureas with mercury(II) oxide resulted in 2-aminobenzimidazole intermediates, which were monoalkylated on the endo-nitrogen atom. After deprotection of the piperidine nitrogen atom with 48% aqueous hydrobromic acid solution, the title compounds were obtained by three different methods, viz. alkylation, reductive amination, or oxirane ring-opening reactions. The in vivo antihistaminic activity was evaluated by the compound 48/80 induced lethality test in rats and histamine-induced lethality test in guinea pigs after oral and/or subcutaneous administration. The duration of action, for a selected number of compounds, was studied in the guinea pig. The phenylethyl derivatives showed the most potent antihistamine properties after oral administration in both animal species.

In vivo pharmacology of astemizole, a new type of H1-antihistaminic compound

Astemizole (R 43 512), a chemically novel compound, has been studied for its in vivo histamine H1-antagonizing properties in laboratory animals. The test models used were: in rats, protection from compound 48/80-induced lethality and inhibition of histamine-induced skin reactions; in guinea-pigs, protection from histamine-induced fatality and bronchoconstriction and in dogs, inhibition of histamine-and Ascaris allergen-provoked skin oedema formation. When compared to standard antihistamines, astemizole showed a higher oral potency and a longer duration of action in all animal models studied. Astemizole's activity was highly specific: it exerted only weak antiserotonin and no anticholinergic actions. Behavioral and drug interaction studies showed that it was devoid of depressant or stimulatory effects on the central nervous system (CNS). Astemizole was very atoxic: safety margins were greater than 25,000 in rats and mice, 30,800 in guinea-pigs and greater than 2000 in dogs. The data of this study indicate that astemizole can be described as a potent, exceptionally long-acting and selective histamine H1-antagonist, free of central and toxic effects.