PMX2B,a new candidate gene for Hirschsprung's disease

Hirschsprung's (HSCR) disease is a congenital intestinal malformation of the enteric nervous system. It is a multigenic malformation and until now, eight genes have been involved in the etiology of this disease: genes encoding proteins of the RET signaling pathway (RET, GDNF and NTN), genes participating in the endothelin (EDN) type B receptor pathway (EDNRB, EDN3 and ECE-1), the SOX10 gene and the SIP1 gene that is mutated in syndromic forms of HSCR. Mutations of these genes are found in not more than 50-60% of affected individuals. Here, we report on the results of a molecular cytogenetic study performed in a girl who presented with a syndromic short segment HSCR associated with a de novo t(4;8)(p13;p22) translocation. A comparative genomic hybridization (CGH) study found a 4p12p13 deletion. A molecular characterization of this rearrangement showed that the 4p13 deletion was 5 Mb in length and included the paired mesoderm homeobox gene (PMX2B) (MIM 603851), a gene expressed in the human embryonic gut and essential for the development of autonomic neural crest derivatives. The present observation suggests that PMX2B haploinsuffciency might predispose to HSCR.     

Die Beurteilung des Kollagenstoffwechsels mittels Hydroxyprolin im Serum und Urin und der Serum-Kollagenpeptidase unter verschiedenen Diätformen

Zusammenfassung Zur Klärung der Frage, ob zwischen Bergleuten mit einer Silikose und Gesunden Unterschiede in der Ausscheidung von Hydroxyprolin (HP) im Sammelurin bestehen und ob diese Messung durch einfacher zu bestimmende Parameter ersetzt werden kann, wurden an insgesamt 34 Probanden HP-Bestimmungen im Sammelurin und im Blutserum sowie die Bestimmung der Serum-Kollagenpeptidase durchgeführt.Die HP-Bestimmungen im Urin und Serum unter verschiedenen Diätformen zeigen, daß eine 24stündige prolinarme Diät vor Beginn der Urinsammelperiode sowie die Weiterführung während der Sammelperiode genügt. Das peptidgebundene HP — bestimmt aus der Differenz von Gesamt-HP und dem ohne Hydrolyse gemessenen HP — weist keine Unabhängigkeit von der Diät auf. Zu den HP-Mengen im Sammelurin haben die Serumwerte eine enge Parallelität. Allein die Kollagenpeptidase ist von der Diät unabhängig und scheint ein geeignetes Maß zur Beurteilung der Aktivität des Kollagenstoffwechsels zu sein.Zwischen Bergleuten mit einer Silikose und Gesunden fanden sich keine Unterschiede.Mit finanzieller Unterstützung der Bergbau-Berufsgenossenschaft Bochum     

Mapping of sporulation-specific functions in the yeast syntaxin gene<Emphasis Type="Italic"> SSO1</Emphasis>

The yeast Saccharomyces cerevisiae has two closely related plasma membrane syntaxins, Sso1p and Sso2p, which together provide an essential function in vegetative cells. However, Sso1p is also specifically needed during sporulation; and this function cannot be provided by Sso2p. We used fusions between SSO1 and SSO2 to map the sporulation-specific function of SSO1. We found that the two N-terminal -helices Ha and Hb of Sso1p are important for sporulation, since it is reduced 8-fold for fusions where Ha and Hb are derived from Sso2p. In contrast, the C-terminal half of Sso1p does not seem to be specifically required for sporulation. Surprisingly, we further found that the 3 untranslated region (3UTR) of SSO1 is essential for sporulation. Western blots failed to reveal a preferential expression of Sso1p in sporulating cells, indicating that effects on gene expression are unlikely to explain why the SSO1 3UTR is needed for sporulation.Communicated by S. Hohmann     

The pregnancy-associated α2-glycoprotein (α2-PAG) A tumour marker?

Summary Long-term studies of 2-PAG in sera of patients with breast cancer, bronchial carcinoma, gynaecological carcinoma, melanoma and laryngeal carcinoma have proved that 2-PAG is a possible laboratory parameter for the assessment of recurrence of tumour and metastasis. The results published for trophoblastic tumour and gastrointestinal carcinoma are still divergent. Because of the large individual range of 2-PAG concentrations and the widely differing 2-PAG levels in men and women single determinations of this protein are without value. A detailed classification of the pathological mechanisms to which these proteins are submitted is still missing and consequently we have no fundamental knowledge of diseases that apart from pregnancy and neoplasia lead to changes in the physiological 2-PAG serum concentration.Dedicated to Prof. Dr. E. Schmiedt to his 60th birthday (20th of November 1980)     

Renovaskuläre Hypertonie

Zusammenfassung In der vorliegenden Untersuchung wurde das postoperative Blutdruckverhalten bei 35 Patienten mit renovaskulärer Hypertonie untersucht: 17 Patienten mit fibromuskulärer Dysplasie (FMD) und 18 mit arteriosklerotischen Gefäßwandveränderungen (ASS).Patienten mit FMD waren im Mittel jünger (31,8 Jahre), zeigten eine kürzere Hypertonieanamnese (1,8 Jahre) und waren prävalent weiblich (82%), während Patienten mit ASS deutlich älter waren (48,2 Jahre), eine längere Hypertoniedauer (2,6 Jahre) zeigten und bevorzugt männlich (78%) waren.In beiden Gruppen zeigte das intravenöse Pyelogramm einen vergleichbar hohen Anteil positiver Befunde (FMD=64%, ASS=61%).Postoperativ waren in der Gruppe mit FMD 47% (n=8) geheilt, 47% (n=8) gebessert und nur 6% (n=1) der Patienten geringgradig gebessert. Die vergleichbaren Werte für die Gruppe mit ASS betrugen 28, 55 und 17%. Für das Gesamtkollektiv war folglich ein guter Operationserfolg (geheilt und gebessert) in 88,5% der Fälle zu beobachten. Patienten mit ASS und postoperativ nur geringgradiger Besserung (n=3) zeigten eine auffallend lange Hypertonieanamnese (7,0±1,4 Jahre).Bei allen Patienten wurde präoperativ die seitengetrennte Bestimmung der Renin-Aktivität (PRA) im Nierenvenenblut durchgeführt und aus den Werten die PRA-Quotienten (PRA betroffene/nicht betroffene Seite) errechnet. Bei 27 Patienten wurde die Bestimmung 15 und 30 min nach intravenöser Stimulation mit 40 mg Furosemid wiederholt. PRA-Quotienten von 1,5 wurden als signifikant bezeichnet.Bei 31 Patienten mit einseitiger renovaskulärer Hypertonie wurde die Höhe des PRA-Quotienten zum postoperativen Blutdruckverhalten korreliert. Dabei zeigte sich zwischen der Gruppe der postoperativ Geheilten und der der postoperativ Gebesserten kein signifikanter Unterschied im mittleren PRA-Quotienten. Ferner ließen sich für das Gesamtkollektiv der 31 Patienten mit einseitiger renovaskulärer Hypertonie unter Ausgangs- und Stimulationsbedingungen keine signifikanten Korrelationen zwischen Höhe der PRA-Quotienten und postoperativem Blutdruckabfall ermitteln.Unsere Ergebnisse unterstützen nicht die weit verbreitete Ansicht, daß sich die seitengetrennte Bestimmung der PRA im Nierenvenenblut als Parameter für den zu erwartenden Operationserfolg bei Patienten mit einseitiger renovaskulärer Hypertonie eignet. Die Methode kann deshalb nach unserer Ansicht nicht mehr als obligater Bestandteile der präoperativen Diagnostik der renovaskulären Hypertonie empfohlen werden.     

Endokrin aktive Tumoren des Ovars

Zusammenfassung Die wichtigsten Vertreter der hormonal aktiven Ovarialtumoren sind in der Gruppe der Keimstrang-Stromatumoren zusammengefasst. Sie machen weniger als 5% der Ovarialgeschwülste aus. Die Mehrzahl der Keimstrang-Stromatumoren besitzt die Fähigkeit zur Biosynthese von Steroidhormonen. Die pathologische Hormonbildung bewirkt spezifische Effekte an den hormonsensitiven Organen. Die klinischen Befunde sind abhängig von Art und Intensität der Hormonproduktion und vom Lebensalter der Patientin. In der Dignität stehen die Keimstrang-Stromatumoren als fakultativ maligne Geschwülste zwischen den nichtinvasiven (Borderline-) und den invasiven epithelialen Tumoren des Ovars. Neben den speziellen zur Hormonbiosynthese befähigten Ovarialgeschwülsten (Keimstrang-Stromatumoren, Steroidzelltumoren) können benigne und maligne Ovarialtumoren verschiedenen Typs aufgrund einer Vermehrung und/oder Stimulation von nicht-neoplastischen Zellen im Ovarialstroma endokrine (östrogene oder androgene) Aktivität aufweisen.

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Induction of lymphokine-activated killer cells with low-dose interleukin 2 and interferon-γ in oral cancer patients

Lymphokine-activated killer (LAK) cells were induced with low-dose recombinant interleukin 2 (rIL-2) and recombinant interferon- (IFN-) in 28 oral carcinoma patients. The patients received daily intravenous injections of rIL-2 (1.2×10⁵ U/m²) and rIFN- (7.0×10⁴ U/m²), and both natural killer (NK) and LAK activities were periodically examined. A significant increase in CD16⁺CD57⁺ and CD16⁺CD57^– NK subsets was observed after the induction. An increase in the T-cell population was also found, with a significant increase in CD3⁺HLA-DR⁺, CD8⁺Leu8^–, and CD4⁺Leu8^– cells. Significant increases in NK activity, from the original level of 32.0±13.7 to 49.9±15.2%, and LAK activity, from 4.8±3.5 to 11.0±6.1%, at Day 7 were observed. Both activities were maintained at high levels during the cytokine injections, but greater enhancement of the killing activities could not be obtained subsequently. When NK and LAK activities were investigated in each subpopulation of CD3^– and CD16^– cells, no remarkable cytotoxic activity could be observed before induction in any subset without NK activity in CD3^– cells (31.1±14.3%). At Day 7, NK activity of CD16^– cells increased up to 21.4±14.9%, accompanied by an increase in CD3^–-cell activity (54.5±20.6%). LAK activities of both subsets were also enhanced, with activity at Day 7 of 6.5±5.6 and 9.4±6.6% in CD16^– and CD3^– cells, respectively. These increased activities were maintained at the same level during the induction. Phorbol myristate acetate-induced polymorphonuclear leukocyte (PMNL) O ₂ ^– generation was significantly increased, from the original 81.1±28.1 to 95.6±34.9 pmol/min/10⁴ cells, after 1 week of treatment. Protein kinase C activity in the cytosol decreased, and the activity in the membrane fraction conversely increased. No remarkable adverse effects except for mild fever were observed. Together with LAK induction ability and PMNL enhancement, with scarce toxicity, a combination of low-dose rIL-2 and rIFN- is thought to be useful in cancer treatments.     

Effects of the irreversible α-adrenoceptor antagonists phenoxybenzamine and benextramine on the effectiveness of nifedipine in inhibiting α 1- and α 2-adrenoceptor mediated vasoconstriction in pithed rats

Summary In pithed normotensive rats, i.v. injection of the selective ₁-adrenoceptor agonist cirazolien produced vasoconstriction which was largely resistant to inhibition by nifedipine. On the other hand, the pressor effects of the selective ₁-adrenoceptor agonists St 587 and Sgd 101/75 were much more effectively blocked by nifedipine, although not as effectively as the pressor effects to the selective ₂-adrenoceptor agonist B-HT 920. The sensitivity to inhibition of vasoconstriction in pithed rats to the different agonists increased in the order cirazoline St 587 ₁-, but not to ₂-adrenoceptor activation was dose-dependently enhanced. The potency of nifedipine to inhibit ₁-vasoconstriction by cirazoline, St 587 and Sgd 101/75 was increased maximally to the level of efficacy at which nifedipine antagonized B-HT 920-induced vasoconstriction. The dose of phenoxybenzamine required to maximally increase the potency and efficacy of nifedipine to antagonize vasoconstriction of the ₁-adrenoceptor agonists was inversely related to the level of sensitivity to blockade by nifedipine of the vasoconstriction they produced. In contrast, pretreatment of rats with the irreversible antagonist, benextramine (10 mg/kg, i.v., –100 to –60 min) did not increase the potency or efficacy of nifedipine to antagonize vasoconstriction to cirazoline, St 587, Sgd 101/75 or B-HT 920, despite irreversible blockade of ₁- and ₂-adrenoceptors. These data suggest that phenoxybenzamine, but not benextramine, selectively inhibits the ₁-adrenoceptor mediated vasoconstrictor mechanism that is independent of influx of extracellular calcium. Moreover, the results show that the existence of receptor reserve or the number of ₁-adrenoceptors activated does not determine the relative contribution of calcium influx-independent mechanisms in ₁-adrenoceptor-mediated vasoconstriction.Preliminary data were communicated at the Joint Meeting of the French and German Pharmacological and Toxicological Societies, Freiburg i. Br., September 19–22, 1983 (Timmermans et al. 1983a) and at the Winter Meeting of the British Pharmacological Society, London, January 1984 (De Jonge et al. 1984)     

The influence of molecular structure on the affinity and efficacy of some β-adrenoceptor agonists

Summary The affinity and efficacy of a number of sympathomimetic amines structurally related to prenalterol and the selective ₁-adrenoceptor agonist RO 363 were determined using a combination of radioligand binding and organ bath techniques. Affinity of the molecules (pK _D) was calculated from their ability to displace the radioligand [¹²⁵I]iodocyanopindolol ([¹²⁵I]CYP) from -adrenoceptor sites in left atrial (₁) and uterine (₂) membrane homogenates. These pK _D values were used to calculate efficacy from the positive inotropic and uterine relaxant responses elicited by the drugs in organ bath experiments. The drugs studied were either arylethanolamines i.e., (–)-isoprenaline (ISO), p-hydroxyisoprenaline (pOH-ISO), compounds XIV and XVI or aryloxypropanolamine-derivatives, i.e., oxymethylene-isoprenaline (OM-ISO), prenalterol and Compound XI which possessed ap-phenol or catechol ring and an isopropyl or a homoveratryl amine substituent. Only ISO, OM-ISO, pOH-ISO and Compound XVI were active as agonists in both tissue preparations. These drugs were partial agonists which exhibited a wide range of pD₂ values and did not display any marked selectivity for either -adrenoceptor subtype. Compound XI and prenalterol were inactive as agonists and together with the partial agonists behaved as competitive antagonists to ISO in the two preparations. All drugs tested displaced [¹²⁵I]CYP from -adrenoceptor sites, however, there was also a wide range of potency amongst the drugs.Analysis of the structure-affinity and structure-efficacy relationships indicated that removal of the 3-hydroxyl group from the catechol ring reduces both affinity and efficacy without altering the selectivity of the drug for either -adrenoceptor subtype. While aryloxypropanolamine derivatives have generally higher affinities than arylethanol-amines, especially at -adrenoceptor sites, their efficacies are generally reduced at both -adrenoceptors. The presence of a homoveratryl group in aryloxypropanolamines enhances slightly the affinity for ₁- and reduces affinity for ₂-adrenoceptors. With this amine group, efficacy is markedly reduced at ₂- as opposed to ₂-adrenoceptor sites.Thus for prenalterol, the small degree of cardioselectivity can be attributed to the oxymethylene group whilst its lack of agonist activity (i.e., efficacy) reflects a combined action of this group and the absence of the 3-hydroxyl group on the phenyl ring. In RO363 it can be deduced that the oxymethylene group, together with the homoveratryl substituent are responsible for the observed selective affinity of the drug for ₁- as opposed to ₂-adrenoceptors.