Biomedical subjects

K Erb

Publications and source records attributed to K Erb.

At least 37 records · Page 2Linked to original sources

PubMed1997

Pilot scale purification of human monoclonal IgM (COU-1) for clinical trials.

No standard procedure is available for the purification of human monoclonal antibodies for human i.v. administration. Here we describe the procedure developed for pilot scale purification of the human IgM monoclonal antibody COU-1 directed against a cancer-associated antigen. The hybridoma cells were grown in protein-free medium and purification from the clarified culture supernatant was carried out in 4 simple chromatographic steps: (1) hydroxylapatite chromatography; (2) hydrophobic interaction chromatography on phenyl-Sepharose: (3) cation-exchange chromatography on sulphonyl-Sepharose; and (4) anion-exchange chromatography on tetraethylamino-Sepharose. The product was substantially pure with regard to protein after step 3, but contained DNA which was removed in step 4. The average recovery of the IgM was 54% with a range of 40-65%. Importantly, the ability of the antibody to bind to its antigen in ELISA was fully maintained during the purification. Subsequently, the purified antibody was isotope labelled and successfully used for in vivo detection of colon, rectal and pancreas carcinomas in patients. The purification procedure described appears to compare favourably with previously published methods, but a critical comparison is not possible due to the lack of necessary information in the available literature.

Antibodies, Monoclonal↗

PubMed1997

Spinally delivered nociceptin/orphanin FQ reduces flinching behaviour in the rat formalin test.

The aims of this study were to investigate the dose-dependent effects of spinally delivered nociceptin (0.3, 1, 3.3 and 10 nmol) on flinching behaviour in the rat formalin test and whether these effects were influenced by the concomitant systemic administration of naloxone (3 mg/kg, i.p.). The effect of the highest nociceptin dose differed statistically from vehicle, 0.3 and 1 nmol nociceptin. Following the administration of 1, 3.3 or 10 nmol nociceptin mean total flinches decreased dose-dependently. The effects of 10 nmol nociceptin were not reversed by a high dose of naloxone. We observed a decrease in flinching behaviour with intrathecally to the lumbar enlargement delivered nociceptin and conclude that nociceptin has antinociceptive effects in the rat formalin test.

Animals↗

PubMed1997

No evidence for decreasing semen quality in four birth cohorts of 1,055 Danish men born between 1950 and 1970.

OBJECTIVE: To compare the quality of semen in 1,055 Danish men born between 1950 and 1970 who are assumed to represent a random sample of the Danish male population of fertile age. DESIGN: Retrospective review of data on semen quality at the time of the female partner's first IVF treatment. SETTING: The Fertility Clinic, Odense University Hospital, Odense, Denmark. PATIENT(S): One thousand fifty-five male partners of women with tubal infertility who were referred for IVF treatment consecutively during the period 1990-1996. INTERVENTION(S): Analysis of the semen samples delivered and used in connection with the couples' first IVF treatment. MAIN OUTCOME MEASURE(S): Year of birth, age at time of sample collection, sperm concentration, and semen volume. RESULT(S): The mean sperm concentration (+/- SD) was 183.7 x 10(6) mL and the mean semen volume (+/- SD) was 3.9 mL. A considerable variation in both parameters was found from year to year, but no significant change occurred in either parameter throughout the entire period. When four birth cohorts were compared, a later year of birth was not associated with any change in sperm concentration or semen volume. CONCLUSION(S): Sperm concentration and semen volume were not related to year of birth, indicating that sperm quality has not changed in the Danish male population during the last 20-30 years.

Adult↗

PubMed1997

Reduced in vitro fertilization of human oocytes correlates with raised circulating FSH levels during ovarian stimulation in normogonadotropic women downregulated with GnRH-analogues.

PURPOSE: The possible effects of circulating FSH levels as used during IVF treatment on oocyte maturation and subsequent preembryo development were evaluated. METHODS: Serum levels of FSH and LH on days 1 and 8 of ovarian stimulation and on the day of oocyte retrieval (OR) were correlated with subsequent preembryo development in vitro. After pituitary downregulation, 244 normogonadotropic women followed a fixed protocol for the first 7 days of stimulation. RESULTS: The average FSH concentration on day 8 of stimulation was 11.5 IU/L and exceeded the expected midcycle surge of FSH by more than 25%. In contrast, levels of LH were below an average of 2 IU/L throughout the stimulation period. The concentration of FSH on day 8 and on the day of OR showed a significant inverse correlation with cleavage rate, whereas levels of LH, age, and body mass index showed no such correlation. CONCLUSIONS: Supraphysiologic levels of FSH seems to affect oocyte maturation negatively. Premature resumption of meiosis, leading to retrieval of postmature oocytes with a reduced developmental potential, is suggested as the underlying mechanism.

Adult↗

PubMed1997

Evaluation of the noninvasive estimates of cardiac output by Doppler aortoechography according to test-theoretical principles.

The usability of noninvasive methods can be quantified by a formal assessment of empirical quality criteria based on test-theoretical principles. The ACVF Doppler aortoechography is a pulsed dual-beam ultrasound technique with online estimates of cardiac output (CO) based upon the measurement of the mean Doppler shift frequency across the ascending aorta, its estimated cross-sectional area and the cycle's heart rate. The method has a relatively high reliability, sensitivity, and pharmacosensitivity (for inodilatory changes in particular), but tends to underestimate cardiac output. Furthermore, the method lacks objectivity because it is highly observer-dependent. Precise method description and stringent standardization thus are required. Because of the method specificity of its estimates, data should not be combined with those of other methods. The inherently poor validity of its CO estimates, using this method, call for caution in the mechanistic interpretation of its observations.

Adult↗

PubMed1996

Murine epidermal Langerhans cells do not express inducible nitric oxide synthase.

In Leishmania-infected macrophages (M phi), the formation of reactive nitrogen intermediates by the inducible isoform of nitric oxide synthase (iNOS) is critical for the killing of the intracellular parasites. We have recently shown that, in addition to M phi, epidermal Langerhans cells (LC) can phagocytose Leishmania major, but they do not allow parasite replication. Therefore, we analyzed whether LC and M phi display the same leishmanicidal effector mechanism. Unlike M phi, stimulation of unselected epidermal cells with interferon-gamma/lipopolysaccharide did not lead to the release of nitric oxide (NO), and inhibition of NO production had no effect on the rate of infection of LC. iNOS mRNA was clearly detectable in M phi as well as unselected epidermal cells (the majority of which consists of keratinocytes) after stimulation with different cytokines. In contrast, pure LC obtained by single-cell picking from cytokine-activated or L. major-infected epidermal cells did not express iNOS mRNA. Addition of the NO donor S-nitroso-N-acetylpenicillamine to already-infected LC did not alter their rate of infection, indicating that LC do not utilize exogenous NO for the control of intracellular Leishmania. These results suggest that in the L. major-infected skin, activated M phi and keratinocytes, but not LC have the ability to express iNOS activity. Therefore, an as yet unidentified, NO-independent mechanism appears to be responsible for the control of parasite replication in LC.

Animals↗

PubMed1996

Influence of antihypertensive therapy with cilazapril and hydrochlorothiazide on the stiffness of the aorta.

The purpose of this study was to examine the effects of the angiotensin-converting enzyme (ACE) inhibitor cilazapril on the elastic properties of the aorta. A standard diuretic antihypertensive drug, hydrochlorothiazide, served for comparisons. Increased aortic stiffness leads to a reduction of the buffering windkessel function and is a major component in the pathophysiology of systolic hypertension, inducing an increase in left ventricular afterload and arterial pulsatile stress as well as a decrease in the subendocardial blood supply. Stiffness of arteries increases with age and blood pressure, and depends on the functional elastic structures of the aortic wall. ACE inhibitors have been shown to directly influence elastic properties of peripheral arteries. Seventeen patients with mild to moderate essential hypertension (age 45-67 years) were treated for 3 months double-blind randomized with either cilazapril (C) 5 mg daily (n = 9) or hydrochlorothiazide (HCTZ) 25 mg daily (n = 8). Aortic elastic properties were noninvasively assessed by measurement of pulse wave velocity along the aorta at rest and during isometric handgrip stress. Accelerated pulse wave velocity indicates elevated arterial stiffness and vice versa. A pressure standardized index of aortic cross-sectional distensibility (2 m) was calculated from arterial mean pressure and pulse wave velocity. Compared with pretreatment values, both therapies significantly reduced blood pressure and pulse wave velocity at rest (C: 9.4 +/- 0.9 vs. 7.7 +/- 0.7 m/sec; HcTZ: 8.9 +/- 0.3 vs. 7.8 +/- 0.4 m/sec; means +/- SEM p < 0.05). During isometric stress only C showed a significant decrease in pulse wave velocity (C: 11.3 +/- 0.8 vs. 9.1 +/- 0.8 m/sec; HCTZ: 9.9 +/- 0.5 vs. 9.0 +/- 0.5 m/sec; means +/- SEM p < 0.05). The index 2m at rest and during handgrip increased significantly (p < 0.05) after C but not after HCTZ. With cilazapril we obtained steeper slopes for the treatment-induced reductions in blood pressure and pulse wave velocity for both rest and handgrip stress values. Correlation of the data at rest and during stress revealed a direct relationship between blood pressure and pulse wave velocity. HCTZ linearly extended the relation observed before treatment toward lower values of blood pressure and corresponding pulse wave velocity without changing the relation per se. Cilazapril, in contrast, moved the relation between these variables and decelerated the pulse wave velocities to a greater extent than would have been expected from the corresponding blood pressure reduction (delta approximately 1 m/sec). These results in patients with mild to moderate essential hypertension support the idea that ACE inhibitors, in addition to reducing blood pressure, may exert an additional hemodynamic effect in improving the elastic properties of the aorta.

Adult↗

PubMed1996

Cutaneous leishmaniasis: a model for analysis of the immunoregulation by accessory cells.

In the mammalian host, Leishmania are obligate intracellular parasites and invade macrophages and Langerhans cells. The accessory functions of both types of host cells are important for regulation of the specific cellular immune response and involve the following activities: infiltration into the site of infection, initiation of a T cell response, maintenance of immunity and the effector mechanisms that control intracellular parasite replication.

Animals↗

PubMed1996

Leishmania major infection in major histocompatibility complex class II-deficient mice: CD8+ T cells do not mediate a protective immune response.

In order to evaluate the role of CD8+ T cells in cutaneous leishmaniasis, major histocompatibility complex (MHC) class II-deficient mice of C57BL/6 background lacking functional CD4+ T cells were infected with Leishmania major. In contrast to C57BL/6 wild-type mice which are resistant to infection with L. major, these mice developed severe skin lesions that did not heal. In comparison to susceptible BALB/c mice, however, lesion development in MHC class II-deficient mice was very much retarded, even though the increase in the parasite load in lymphoid organs was only slightly delayed. Lymph node cells from L. major-infected MHC class II-deficient mice produced very low levels of interferon-gamma upon stimulation with L. major antigen, whereas the response to the mitogen concanavalin A was not impaired. Interestingly, they did not release lymphokines associated with disease exacerbation (interleukin 4 and interleukin 10) either, suggesting that the delayed lesion development is caused by the lack of disease-promoting CD4+ cells rather than by the presence of protective CD8+ cells. The lack of L. major-reactive immunoglobulins in the serum of infected MHC class II-deficient mice indicates that B cells also cannot respond to parasite antigens in the absence of MHC class II-mediated helper signals. The data demonstrate that MHC class II-deficient mice are unable to restrict the spreading of L. major, although they contain highly increased proportions of CD8+ T cells. Thus, MHC class II-restricted immune responses, most likely mediated by functional CD4+ T cells, are essential for the control of primary infections with L. major.

Animals↗

PubMed1996

The effect of human menopausal gonadotrophin and highly purified, urine-derived follicle stimulating hormone on the outcome of in-vitro fertilization in down-regulated normogonadotrophic women.

It has been suggested that the luteinizing hormone (LH) activity of human menopausal gonadotrophin (HMG) preparations used for ovarian stimulation in in-vitro fertilization (IVF) may have adverse effects on reproductive outcome. In the present prospective, randomized trial of 218 infertile couples this notion was investigated. A total of 114 women were treated with Pergonal (HMG group) and 104 with Fertinorm HP (HP-FSH group). The two groups were comparable with regard to duration of infertility, cause of infertility, age and number of previous IVF attempts and all had normal basal gonadotrophin concentrations before treatment was started. A standard hormonal treatment consisting of pituitary down-regulation with gonadotrophin-releasing hormone analogue (GnRHa) for 14 days starting on cycle day 21, followed by either HMG or highly purified follicle stimulating hormone (HP-FSH), three ampoules (225 IU) per day for 7 days, was used in all cases. The daily hormone dose was thereafter individualized according to the ovarian response. A maximum of two pre-embryos were transferred after 3 days of culture. Luteal support with progesterone (300 mg per day intravaginally) was used in all cases. Serum concentrations of oestradiol, FSH and LH were measured on days 1 and 8 of stimulation and on the day of oocyte retrieval. The mean number of days of stimulation, mean number of ampoules of HMG or HP-FSH used, mean total motile sperm count on the day of oocyte retrieval and mean numbers of oocytes retrieved (13.4 versus 13.7) or pre-embryos transferred (1.8 versus 1.8) were similar for both groups. Significantly (P < 0.05) more cycles in the HP-FSH group (17 = 16%) were cancelled due to complete failure of fertilization than in the HMG group (7 = 6%). The mean fertilization rate was significantly (P < 0.05) higher in the HMG group (56%) than in the HP-FSH group (50%), and significantly more transferable pre-embryos were obtained in the HMG than in the HP-FSH group (mean: 4.0 versus 3.2; P < 0.01). Serum hormone concentrations were similar to the two groups on stimulation day 1, but differed significantly with regard to FSH, LH and oestradiol on stimulation day 8. The clinical outcome was similar in the two groups, with an ongoing pregnancy rate (> 12 weeks of gestation) per started cycle of 33% in the HMG group and 29% in the HP-FSH group. The clinical abortion rates were similar (10 and 14%), and the implantation rate was 30% in each group. In conclusion, no detrimental effect of the LH activity of HMG on the clinical outcome of IVF in GnRHa down-regulated normogonadotrophic women was found. To the contrary, some beneficial effects of HMG on fertilization rates and pre-embryo development as compared with HP-FSH were demonstrated. These effects, as well as the differences in serum hormone concentrations during ovarian stimulation, may be caused by differences in LH content and/or in the composition of FSH isoforms of the HMG and HP-FSH preparations.

Adult↗

PubMed1996

Transfer of different nonsteroidal antiinflammatory drugs via the lymphatic system in the rat.

The motility of lymphatic vessels is regulated by arachidonate metabolites and can, therefore, be altered by cyclooxygenase blockers such as nonsteroidal antiinflammatory drugs (NSAIDs). To investigate the transfer of different NSAIDs via the lymphatic system, pharmacokinetics in plasma and lymph after peroral administration of three model compounds (namely, racemic ibuprofen, tenoxicam, and nabumetone) were investigated in rats. Microsurgical cannulation of the thoracic duct allowed cumulative sampling of lymph fluid up to 48 hr (N = 16). Pharmacokinetic parameters in plasma were determined in a control group (N = 12). Concentrations of R-ibuprofen, S-ibuprofen, tenoxicam, nabumetone, and the metabolites OH-ibuprofen, COOH-ibuprofen and 6-methoxy-2-naphthylacetic acid (6MNA; a metabolite of nabumetone) were monitored in lymph and plasma by HPLC. The observed peak concentrations in lymph of the investigated drugs are likely to produce different biological effects with regard to cyclooxygenase-1 inhibition. To quantify the appearance in lymph fluid, a "lymphatic clearance" of the investigated compounds was defined by dividing the amount recovered in lymph by the corresponding area under the plasma concentration-time curve. The "lymphatic clearance" differed substantially between the investigated compounds (mean +/- SD: R-ibuprofen, 19.8 +/- 9.4; S-ibuprofen, 9.6 +/- 3.6; tenoxicam, 32.5 +/- 31.3; nabumetone, 133.6 +/- 75.2; 6MNA, 18.3 +/- 8.5 microliters/min/kg). Overall recovery of the investigated compounds in lymph did not exceed 5% of the doses given. The known fact that lymphatic drainage is regulated by arachidonate metabolites suggests that NSAIDs differing in their transfer via the lymphatic system could result in different responses of lymphatic vessels to an inflammatory fluid load.

Animals↗

PubMed1996

Differentiation of inodilatory responses by non-invasive measures of cardiovascular performance in healthy man.

The cardiovascular responses to various inodilatory interventions were investigated noninvasively in healthy man by monitoring heart rate (HR), blood pressure (SBP/DBP, according to Korotkoff I and IV criteria), systolic time intervals (PEP, VET and QS2) and impedance cardiographic estimates of stroke volume (SV) and cardiac output (CO). The following inodilatory interventions were evaluated and compared: the i.v. infusion of adrenaline (1 microgram/min), the i.v. infusion of isoprenaline (1 microgram/min) with and without pretreatment with 100 mg talinolol (a beta 1-selective beta-adrenoceptor antagonist), the p.o. administration of 1200 mg celiprolol (a beta 1-adrenoceptor antagonist with ancillary beta-adrenergic agonistic properties at the chosen dose level), the p.o. administration of 0.4 mg bimakalim (a K+ channel activator without direct cardiac effect) with and without pretreatment with 5 mg bisoprolol and the p.o. administration of the PDE-III inhibitors meribendan and isomazole. The extent of the inodilatory rise of HR, shortening of PEP, rise of SV and CO relative to the associated reduction of the calculated total peripheral resistance (TPR) proved a powerful tool to differentiate inodilatory properties: adrenaline, isoprenaline after beta 1-selective beta-adrenoceptor blockade and celiprolol led to similar ancillary adrenaline-like cardiovascular changes relative to the vasodilatation; bimakalim led to similar associated changes except for a relatively larger rise in HR, which could be blocked by bisoprolol; isoprenaline induced clearly larger associated changes, for which HR, VET, and QS2c were particularly sensitive; meribendan and isomazole resulted in the largest ancillary changes, characterized by a critical shortening of the ejection time VET, so that the rise of CO was almost exclusively defined by the rise of HR. These differences could be detected and differentiated sufficiently and adequately by HR, SV, CO, TPR, PEP, and VET. There seems little value in using more assumptive variables such as HR-corrected VETc and QS2c, the Weissler index and the impedance cardiographic Heather index.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1995

Clinical pharmacological equivalence of a novel FCH-free GTN spray with low ethanol content vs a FCH-containing GTN spray.

The overall therapeutic equivalence of a fluorochlorohydrocarbon (FCH)-free glyceryl trinitrate (GTN) pump spray with a low ethanol content (TL) was investigated relative to an FCH-containing GTN spray (Nitrolingual; R), in terms of: (1) pharmacokinetic bioavailability, (2) pharmacodynamic responses as assessed by digital plethysmography (DPG), and (3) clinical perception upon application. Pharmacokinetically, the time courses of the plasma concentrations of GTN and its dinitrate metabolites, 1,2- and 1,3-GDN, subsequent to the sublingual administration of 0.8 mg GTN showed somewhat lower bioavailability of GTN and its metabolites than to the reference. Pharmacodynamically, the changes in the DPG signals after the application of 0.8 mg GTN with TL were biostatistically equivalent with R (estimated ratio TL/R for the maximum decrease of the ratio between the systolic a wave and c incisure: 0.98; 90% CI: 0.84-1.14; and for the average decrease of the c: a ratio: 0.97; 90% CI: 0.80-1.16). The time of occurrence of the maximum effect of TL was not significantly different from that of R (estimated difference TL-R: -2.25 min; 95% CI:-9.5 min to 2 min). In contrast, after the administration of an FCH-free GTN spray with a higher ethanol content (TH, active control), the effect had a slightly earlier onset (TH-R: -6 min, 95% CI:-9.5 to -2 min) and there was a higher average response (TH/R: 1.12: 90% CI: 0.95 to 1.34). However, TH was consistently judged to cause an extremely unpleasant burning sensation in the mouth and thus was perceived as distinctly different from R. In contrast, TL was well tolerated and could not be distinguished from R.

Adult↗

PubMed1994

Immunoscintigraphy of colon cancers with the human monoclonal antibody COU-1.

The human monoclonal immunoglobulin M (IgM) antibody, COU-1 is obtained from a human-human hybridoma, which is derived by fusion between a human B-lymphoblastoid cell line and lymphocytes obtained from mesenteric lymph nodes from a patient with colorectal cancer. COU-1 recognizes a 43 kilodaltons intracellularly located cytokeratin-like protein, strongly expressed by adenocarcinoma tissue as compared to normal tissues. In tumor-bearing nude mice, antibody COU-1 labeled with 125I has been shown to accumulate in human colon cancer grafts when compared to human melanoma grafts and the normal mouse tissues. The observed accumulation was sufficient to be detected externally by immunoscintigraphy. Antigen-binding fragments of the antibody were also prepared and were shown to accumulate in colon cancer grafts. Improved tumor to normal tissue ratio was seen with the half-monomeric fragment, and the time required was reduced. In the clinic, five patients with suspected colorectal cancer were given 2 mg of 131I-labeled COU-1. No adverse effects were detected in any of the patients. Planar images were obtained on days 1, 2, 3, 5, and 7 after administration. The best images were obtained on days 5 and 7. Tumors were localized by immunoscintigraphy in four of the patients. Of these patients, surgery revealed that three of them had primary colorectal cancers located in the cecum, the ascending colon, and the rectum, respectively, while one patient had a pancreatic cancer. The smallest lesion observed had a diameter of 3 cm. In one of the patients, otherwise undiagnosed multiple liver metastases were revealed by the immunoscintigraphy and confirmed at surgery. An x-ray of the colon performed on the fifth patient had shown a stricture in the descending colon suspected to be caused by cancer. The tumor scintigraphy showed no accumulation of the antibody. Surgery revealed that the stricture was caused by adherence and not cancer. These findings are encouraging for further studies of this human monoclonal antibody in cancer patients.

Adenocarcinoma↗

PubMed1994

Review of studies on the clinical pharmacodynamics of cilazapril.

Several studies were performed to evaluate the degree of inhibition of angiotensin-converting enzyme (ACE) by an ACE inhibitor by assessing the blood pressure response to a continuous i.v. infusion of increasing doses of angiotensin I in healthy volunteers. We assessed pharmacokinetic and pharmacodynamic interactions of the ACE inhibitor cilazapril and the beta-blocker propranolol in healthy volunteers and patients with essential hypertension. We also evaluated the effect of cilazapril on aortic compliance in hypertension by pulse-wave velocity along the aorta. We showed that single oral doses of cilazapril 4 mg, captopril 25 mg, or enalapril 10 mg shifted the angiotensin I dose-effect curve to the right and determined a pharmacologic half-life of about 4 h for cilazapril. Increasing single oral doses (1.25, 3.75, 10, and 30 mg) of cilazapril reduced diastolic blood pressure dose-dependently and shifted the angiotensin I dose-response curves to the right. The dose representing 50% inhibition of ACE activity (apparent Ki dose) was about 0.6 mg 3 h after cilazapril administration. Cilazapril and propranolol did not exhibit significant pharmacokinetic interaction in healthy volunteers; each drug reduced diastolic and systolic blood pressure by about 7 mm Hg, and this was doubled by the combination. Monotherapy with each drug reduced blood pressure, and combined administration enhanced the antihypertensive effect. The reduction in cardiac output and the increase in total peripheral resistance induced by propranolol were attenuated by the cilazapril-propranolol combination.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1994

[Pharmacodynamic equivalence and clinical trial of a new fluorocarbon-free glycerol trinitrate pump spray with low ethanol content in comparison to a fluorocarbon-containing reference spray and a fluorocarbon-free pump spray with high ethanol content].

The pharmacodynamic equivalence of a fluorohydrocarbons-(FCH)-free glyceryl trinitrate (GTN, CAS 55-63-0)-containing pump spray with low ethanol content (Nitrolingual-Spray N; TL) versus a conventional FCH-containing GTN spray (Nitrolingual-Spray, R) as reference and a FCH-free GTN pump spray with high ethanol content (TH) was investigated by digital plethysmography (DPG) in a double-blinded, placebo-controlled (TL-matched placebo spray), randomized, period-balanced, 4-way cross-over design. Additionally the clinical tolerability (as perceived by the subjects and reported to the treatments-administrating investigator) was determined. The DPG-changes (cla; ratio of c-incisure and systolic a-wave) after the sublingual (s.l.) administration of 0.8 mg GTN of TL were biostatistically equivalent with R: the confidence intervals (CI) of the point estimates of the maximal decrease in cla (TL/R: 0.98, 90%-CI: 0.84 to 1.14) and the area-weighted average decrease in cla (TL/R: 0.97, 90%-CI: 0.80-1.16) were well in a 80-125% tolerance range. The time of occurrence of the maximal DPG-effect of TL was not different from R (distribution-free estimate of the difference TL-R: -2.25 min, 95%-CI: -9.5 min to 2 min). In contrast the maximal DPG-effect of TH after the s.l. administration of 0.8 mg GTN had a statistically significant earlier onset (TH-R: -6 min, 95%-CI: -9.5 min to -2 min) and a higher area-weighted average response (TH/R: 1.12, 90%-CI: 0.95 to 1.34). TH consistently caused an utterly unpleasant burning sensation in the mouth, thus this perceived local discomfort was distinctly different compared to all other treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Sublingual↗

PubMed1993

Tumor detection with 131I-labeled human monoclonal antibody COU-1 in patients with suspected colorectal carcinoma.

A major factor limiting the use of rodent monoclonal antibodies for diagnosis and therapy of cancer is the development of human anti-mouse immunoglobulin antibodies. Here we report a phase I/II immunodetection study of a human monoclonal antibody, COU-1, labeled with 131I. COU-1 is produced by a human-human hybridoma and recognizes a M(r) 43,000 cytokeratin-like protein strongly expressed by adenocarcinomas of the colon, breast, and ovary. Ten patients were given an i.v. infusion of 2 mg of antibody COU-1 labeled with 185 MBq of 131I. No adverse effects or toxicity were detected by conventional clinical tests nor by a complement activation assay for C3d. None of the patients developed antibodies against antibody COU-1 as determined by enzyme-linked immunosorbent assay and agglutination analysis. Tumor detection was successful in 7 of 9 cancer patients. The tenth patient proved to be a true negative. In several instances immunoscintigraphy gave additional or more correct information than conventional detection techniques. Tumors were most clearly outlined at days 5 and 7 after infusion. Primary colorectal carcinomas were detected by planar imaging in the cecum, ascending colon, and rectum with the smallest lesion measuring 3.0 cm in diameter. Immunoscintigraphy revealed multiple liver metastases in 1 of 3 patients. However, the livers of all 3 patients contained significantly more radioactivity (P < 0.005) than tumor-free livers of the other patients. Pharmacokinetics was evaluated in all patients. The clearance of 131I-labeled COU-1 from the circulation followed a triphasic pattern; an initial phase [t1/2 = 0.4 +/- 0.4 (SD) h] cleared 23% of the radioactivity followed by a rapid phase with a half-life of 13 +/- 3.8 h. The third phase (beta-phase) exhibited a half-life of 119 +/- 36 h, which is similar to the half-life reported for normal IgM. The human monoclonal antibody COU-1 directed against a predominantly intracellular cancer-associated antigen does not produce toxicity or induce antibody formation and seems to be a promising agent for detecting tumors with immunoscintigraphy.

Animals↗

PubMed1993

Preparation of antigen-binding monomeric and half-monomeric fragments from human monoclonal IgM antibodies against colorectal cancer-associated antigens.

The large size of human IgM monoclonal antibodies (MAbs) may impede the tumor-localizing capacity. A procedure is described for the preparation of antigen-binding monomeric (IgMm) and half-monomeric (IgM1/2m) fragments from two human IgM MAbs, COU-1 and D4213. The fragments retained binding activity against colon carcinoma. Six different reducing reagents (dithiothreitol, 2-mercaptoethanol, 2-mercaptoethylamine, L-cysteine, metabisulphite, ascorbic acid) were investigated over a range of concentrations, pHs, and incubation periods. The reduced IgM preparations were alkylated with iodoacetamide and fractionated by high-performance gel permeation chromatography. The fractions were directly collected on ELISA plates coated with extracts of colon cancer cells. Antigen-binding IgMm and IgM1/2m fragments were obtained after treatment with mercaptoethanol, mercaptoethylamine, metabisulphite, and cysteine. IgMm and IgM1/2m fragments were also obtained after dithiothreitol treatment. These fragments were, however, nonreactive. The pH during the reduction was important for optimal yields of the fragments. The fragments obtained with 2-mercaptoethanol and mercaptoethylamine were most effective in binding to the cancer cell extract. The association constants per binding site for intact, monomeric, and half-monomeric COU-1 were by competitive inhibition assays estimated at 1.5 x 10(8) M-1, 3.1 x 10(8) M-1 and 4.0 x 10(6) M-1, respectively. The reduction of human IgM MAbs to IgMm and IgM1/2m fragments may facilitate the tumor localization when these are used in the diagnosis and therapy of cancer patients.

Alkylation↗