Laboratory data in healthy volunteers: reference values, reference changes, screening and laboratory adverse event limits in Phase I clinical trials

Objective: Laboratory data are key evaluation procedures for Phase I clinical pharmacology for two reasons. Firstly, laboratory data are used within the screening process to exclude subjects with asymptomatic diseases, which could result in increased danger to themselves or confuse interpretation of the study results. Secondly, during study implementation, safety evaluation and in particular maximum tolerated dose determination have to be done by a case-by-case analysis, sometimes using laboratory adverse events (LAEs). Thus, relevant limits are needed to discriminate between a usual common variation and a significant abnormality, which is considered to be a LAE. This report presents laboratory data distribution, reference values and reference changes and, based on previously published new methods, suggests inclusion limits at screening and laboratory adverse event limits for analysis during study implementation. Subjects and methods: Nine hundred and twenty-seven young healthy male volunteers were recruited in one centre (Association de Recherche Thérapeutique). A standard screening process was carried out. Protocols were approved by the local ethics committee. Blood sampling was performed in the same conditions. Reference values (at screening and at baseline) were determined by a non-parametric procedure selecting 2.5% and 97.5% of the distribution of data. Reference changes were also defined as the 2.5–97.5% interval of distribution of the variations between the end of treatment and baseline. Inclusion limit and LAE limit methods of determination used had been specified in previous articles. Results: Detailed results of laboratory data distribution, reference values at screening and at baseline, reference changes, inclusion limits and LAE limits are presented in tables with number of subjects, mean, median, standard deviation, minimal and maximal values and the 2.5–97.5% interval for each laboratory parameter. Conclusion: The key aims of this paper are to provide clinical pharmacologists with data, reference values or changes obtained in the real conditions of Phase I study implementation, and to propose relevant limits, either for screening as inclusion limits, or during studies as LAE limits. Thus, these data, reference values and specific limits improve the capacity to screen healthy volunteers and to analyse LAEs during Phase I studies. Received: 30 July 1998 / Accepted in revised form: 25 November 1998     

A loudspeaker-driven system for rapid and multiple solution exchanges in patch-clamp experiments

A new and inexpensive system allowing rapid and synchronized changes of solutions around a membrane patch or a cell under voltage-clamp conditions is described. Four plastic capillary tubings (OD 640 m; ID 430 m) were glued together horizontally and attached to a coil of a commercially available loudspeaker. Servo-control of the position of the coil allowed the mouth of any of the capillaries to be positioned near the pipette tip within 6 ms. A high flow speed of the test solution was crucial to achieve rapid solution exchange. At a flow speed of 5 cm/s, complete exchange of the external environment of a frog ventricular cell was achieved within 20–30 ms. The time course of solution change was found to be 3–5 times faster at the tip of an open patch pipette. To preserve the physical integrity of the cell, the cell was usually perfused by a control capillary at a slow velocity (0.2 –0.4 cm/s) and test solutions flowing out of adjacent capillaries at high velocity (4–5 cm/s) were applied to the cell only for short periods. Determination of the three-dimensional contamination profile around the mouth of the control capillary allowed the optimal conditions for the use of the system to be established and possible sources of contamination to be avoided between adjacent capillaries with unmatched flow speeds. Successive and multiple changes in external solutions could be easily synchronized with voltage-clamp depolarizations to examine the time course of the effect of drugs on voltage-operated ion channels. An example of this application is given with rapid applications of the dihydropyridine agonist (-)BayK 8644 to the L-type Ca²⁺ channel current in frog ventricular myocytes.     

Tubular and interstitial factors in the progression of glomerulonephritis

All recent studies of the outcome of different forms of progressive glomerulonephritis concur that a major factor, apparently determining outcome, is the presence and severity of tubulointerstitial changes, and not the degree of glomerular alteration. Moreover, at the time of biopsy, tubulointerstitial changes correlate much better with the glomerular filtration rate. These at first surprising findings are not only useful clinically, but should make us think about our models of how progression takes place in so-called glomerular nephritides. In fact, a major tubulointerstitial infiltrate of immune-competent cells is present in all forms of progressive glomerulonephritis, and again correlates with outcome. In addition, it is now clear the tubular epithelium is capable of synthesising and secreting a number of factors important in fibrogenesis, and of displaying major histocompatibility complex class II antigens and leucocyte-adhesion molecules. Tubular cells could thus present peptides to T helper cells and amplify, or maybe even initiate, immune reactions. Finally, fibrogenesis within the kidney is at last being studied, long after studies have been performed on liver and lung. In the past, too much attention has been paid to reversible inflammation and not enough to irreversible cirrhosis of the kidney.Abbreviations used Ig immunoglobulin, e. g. IgA, IgG, IgM etc. - TBM tubular basement membrane - GBM glomerular basement membrane - WHO World Health Organization - MHC major histocompatibility complex - CD cluster determinant - NK natural killer - IL-1 interleukin-1 - IL-2 interleukin-2 - TNF- tumour necrosis factor alpha - ADCC antibody-dependent complement mediated cytolysis - ACE angiotensin-converting enzyme - m macrophage - ICAM-1 intercellular adhesion molecule-1 - ELAM-1 endothelial leucocyte adhesion molecule-1 - VCAM-1 vascular cell adhesion molecule-1 - LFA leucocyte function associated molecule, e. g. LFA-1, LFA-3 - C complement e. g. C3=third component of complement, etc. - TGF- transforming growth factor beta - TGF- transforming growth factor alpha - PDGF platelet derived growth factor - PAS periodic acid Schiff - TCR T cell receptor - PTEC proximal tubular epithelial cell - GM-CSF granulocyte colony stimulating factor - M-CSF monocyte colony stimulating factor - FGF fibroblast growth factor     

Comparison of renal function and psychomotor performance in workers exposed to elemental mercury

Summary Renal function and psychomotor performance (eye-hand coordination, arm-hand steadiness) of a group of 43 workers exposed to mercury vapor were examined. Their mean age and average duration of exposure to mercury were 38 and 5 years, respectively. The results were compared with those obtained in a matched group of 47 control workers. Increased proteinuria and albuminuria were found slightly more prevalent in the Hg-exposed group than in the control workers. These results are in agreement with those found during a previous study carried out in another group of workers also exposed to elemental mercury (Bucket et al. 1980). The scores of the psychomotor tests were less satisfactory in the Hg workers than in the control workers, the arm-hand steadiness test being more discriminative than the eye-hand coordination test. Preclinical changes in psychomotor function can be detected independently of the presence of signs of renal dysfunction. No clear-cut relationships were found between the prevalence of abnormal psychomotor scores and the level of mercury in blood (HgB) or in urine (HgU). Increased prevalences of abnormal psychomotor scores seem however to occur for HgB between 1 and 2 g/100 ml and for HgU between 50 and 100 g/g creatinine. Therefore, a biologic threshold limit value of 50 g/g creatinine is proposed for urinary mercury to prevent the development of preclinical effects on the central nervous system. A similar critical HgU level based on renal dysfunction prevalences has been suggested in a previous study.This study was supported by a grant from the Commission of the European Communities     

Effect ofβ-adrenergic blockade on haemodynamic responses to dynamic and isometric exercise in angina pectoris

Summary The effect of treatment for 1–4 weeks with metoprolol, a ₁-selective blocking agent, or alprenolol, on the heart rate and blood pressure response to isometric exercise was studied in two groups of 12 patients with angina. Measurements were made during the peak effect of metoprolol 10, 40 or 50 mg, and alprenolol 200 mg as Aptin^® Durules^®. After 1 min of sustained handgrip at 50% of maximal voluntary contraction, systolic (6–15%) and diastolic (8–12%) blood pressure after both drugs was significantly lower than without any -blockade; Heart rate was decreased by 19–22% by metoprolol but not by alprenolol. The blood pressurerise during handgrip was not attenuated by either drug. The rise in heart rate was significantly reduced (by 36–50%) by metoprolol 40 and 50 mg and alprenolol 200 mg. No patient experienced angina during handgrip. In contrast, all but one were restricted by angina during bicycle exercise without treatment, at a level that produced the same increase in heart rate as the handgrip test, viz. 3 min at a load of 33 W). The cardiovascular response to sustained handgrip is too small to provide a useful challenge for determination of the anti-anginal efficacy of drugs. However, slight ECG changes of ischaemia did occur during handgrip, which were reversed by -blockade.     

Early postnatal maturation of GABAA-mediated inhibition in the brainstem respiratory rhythm-generating network of the mouse

It is well established that GABA_A‐mediated postsynaptic potentials are excitatory in many brain regions during embryonic and early postnatal life. The pre‐Bötzinger complex (PBC) in the brainstem is an essential component of the respiratory rhythm‐generating network, where GABA_A‐mediated inhibition plays a critical role in generating a stable respiratory rhythm in adult animals. In the present study, using the perforated patch technique, we investigated the maturation of GABA_A receptor‐mediated effects on rhythmically active PBC neurons and on the motor output in slice preparations from P0–15 neonatal mice. The reversal potential of GABA_A receptor‐mediated current (E_GABA‐A) switched from depolarizing to hyperpolarizing within the first postnatal week. E_GABA‐A was ?13.7 ± 9.8 mV at P0, then it changed to ?44.8 ± 7.0 mV at P2 and ?71.5 ± 6.8 mV at P4. Perfusion of bicarbonate‐free saline has no detectable influence on E_GABA‐A, indicating that a lack of Cl^– extrusion during P0–3 is mainly responsible for early GABA_A‐ergic excitation. At the network level, blockade of GABA_A receptors with bicuculline did not significantly change the frequency of rhythmic bursts recorded from hypoglossal nerve roots before P3, whereas it increased the coefficient of variation. After P3, bicuculline increased burst frequency with little effect on the coefficient of variation. Thus, chloride‐mediated inhibition, which appears in PBC neurons after P3, coincides with the appearance of GABA_A‐mediated modulation of the respiratory rhythm. GABA_A receptor‐activated inhibition may therefore be necessary for frequency modulation in the respiratory network beginning on the fourth postnatal day in the mouse brainstem.     

磷酯酶C对家兔血小板聚集和超微结构的影响

目的　应用电镜研究磷酯酶C(phospholipaseC ,PLC)对家兔血小板聚集和超微结构的影响 ,以探讨用药后PLC抗血小板聚集作用的机制。方法　家兔颈动脉插管取血 ,制备PRP ,将其分为 4组 :①空白对照组 ;②生理盐水组 ;③ 0 5UPLC组 ;④ 2 5UPLC组。 2～ 4组分别用ADP诱导聚集 ,测出其聚集抑制率 ,各组分别制成超薄切片样品进行电镜观察、摄片。结果　 0 5、2 5UPLC明显抑制血小板聚集反应 ,聚集抑制率分别为 86 0 3 %± 12 6%和 82 47%±5 49% ;0 5UPLC抑制血小板形成伪足 ,α颗粒和致密颗粒较多 ,OCS管腔较小 ,其超微结构较生理盐水组变化小 ;2 5UPLC处理血小板的形态结构和超微结构与空白对照组无差异 ,血小板呈圆形或椭圆形 ,边缘光滑 ,无伪足样突起 ,α颗粒、致密颗粒、OCS等正常分布于胞质中。结论　PLC明显抑制ADP诱导的血小板聚集反应及其超微结构的改变 ,这可能是PLC抗血小板聚集作用的重要原因之一     

Gorlin's syndrome: Diffuse appendicular skeletal involvement with scintigraphic correlation

Gorlin's syndrome (also known as basal cell nevus syndrome, Gorlin?Goltz syndrome, and nevoid basal cell carcinoma syndrome) is a rare, inherited disorder characterized by multiple basal‐cell epitheliomas, intracranial calcification, keratocysts of the mandible, and unusual and striking skeletal abnormalities. We present the interesting case of a 45‐year‐old woman who was informed that she had fibrous dysplasia of the extremity at another institution before extensive radiological work‐up showed a diffuse skeletal process. The skeletal abnormalities, in conjunction with the patient's history of multiple basal cell carcinomas, is consistent with the diagnosis of Gorlin's syndrome. We describe this unusual case of striking radiological and scintigraphic findings in a patient with Gorlin's syndrome.     

舌诊与血液流变学的研究

对２６６例慢性病患者以血液的红细胞压积、全血粘度等７项检测为指标，按舌诊中舌体、舌质、舌苔分类，比较舌象与血液流变学的关系。结果，胖大舌红细胞压积明显升高而全血粘度无明显改变，瘦小舌红细胞压积明显降低而全血还原粘度、全血粘度明显升高。发现暗淡舌、暗红舌、暗紫舌红细胞压积值及全血粘度均有不同程度的升高；随舌质由淡、红、紫色的加深，全血粘度质呈递增趋势。血液流变学的指标测定对阐明舌体、舌质的形成原理具有一定价值；舌象可以反映人体血液流变学的一些变化，为中医舌诊辨证的科学性提供了有力证据