Biomedical subjects

M Henzl

Publications and source records attributed to M Henzl.

At least 19 recordsLinked to original sources

PubMed1995

Effects of a gonadotropin-releasing hormone agonist on the calcium-parathyroid axis and bone turnover in women with endometriosis.

OBJECTIVE: Our purpose was to investigate the effects of nafarelin on bone turnover and mass (bone mineral density, in grams per square centimeter) in women with endometriosis. STUDY DESIGN: We monitored 22 young women with endometriosis during and 6 months after 6 months of nafarelin treatment. We compared the bone mineral density status of these women with that of healthy controls undergoing sequential bone mineral density measurement. RESULTS: Subjects had a 2.2% loss in L2-4 bone mineral density by 6 months, increasing 3 months later to 3% and returning toward baseline by 6 months after treatment. Radius bone mineral density did not change in the treatment group. Bone mineral density did not change in controls. Serum and urinary calcium levels rose during treatment. Hydroxyproline excretion increased and remained elevated 6 months after treatment. A rise in serum osteocalcin persisted 3 months after therapy but normalized by 6 months. CONCLUSIONS: Bone mineral density deficits with nafarelin are reversible. Increased bone turnover persists 6 months beyond treatment, demonstrating the need for careful monitoring of women receiving prolonged or repeated treatment.

Adult↗

PubMed1986

Intranasal nafarelin: an LH-RH analogue treatment of gonadotropin-dependent precocious puberty.

The agonistic analogues of luteinizing hormone releasing hormone decrease biochemical findings and clinical signs of gonadotropin-dependent precocious puberty. We tested a new analogue, nafarelin acetate, in 15 girls with gonadotropin-dependent precocious puberty. The hydrophobic nature and potency of this compound allow it to be administered by intranasal inhalation. Laboratory assessment of vaginal cytology, estradiol and urinary gonadotropin levels, and growth velocity revealed that nafarelin acetate 800 to 1200 micrograms/day diminished these values during a 6-month treatment period. These results suggest gonadotropin-dependent precocious puberty in girls can be treated with intranasal administration of nafarelin acetate.

Administration, Intranasal↗

PubMed1985

Treatment of endometriosis with a potent agonist of gonadotropin-releasing hormone (nafarelin).

Administration of superactive agonistic analogs of gonadotropin-releasing hormone (GnRH) has been shown to induce a paradoxic and reversible suppression of gonadotropins, resulting in suppressed gonadal steroid concentrations. Because there currently is no uniformly successful and acceptable medical therapy for endometriosis, we examined the effects of 6 months of nasal administration (500 micrograms every 12 hours) of the agonistic analog of GnRH, nafarelin, on clinical signs and symptoms and hormonal profiles in eight women with endometriosis. All patients had prompt and near-complete relief from their painful symptoms of endometriosis. Laparoscopy or laparotomy, performed both before and after treatment in seven of the women, revealed complete resolution of active endometriotic lesions in five patients and only a single, small cul-de-sac implant in a sixth woman. A large ovarian endometrioma decreased slightly in response to treatment in the seventh woman. Serum luteinizing hormone and follicle-stimulating hormone concentrations, after a transitory stimulation at the onset of treatment, declined and were suppressed (P less than 0.001) during the remainder of treatment. Serum estradiol concentrations fell to approximately menopausal levels (less than 30 pg/ml) after 1 to 4 weeks. Reversibility of drug effect was prompt, with ovulatory menses returning 47 +/- 8 days (+/- standard deviation) after treatment. Thus, nasal administration of agonistic analogs of GnRH may represent a new treatment modality for endometriosis.

Administration, Intranasal↗

PubMed1984

Nuclear proteins that become part of the mitotic apparatus: a role in nuclear assembly?

A structure located at the poles of the mitotic spindle is described, which may function as a centre for post-mitotic nuclear assembly. Evidence in support of this function is incomplete, but comes from two different kinds of experiments, which are reviewed here. First, fluorescence microscopy studies show that mitotic chromosomes at telophase or late anaphase are drawn into juxtaposition with this polar structure and second, the structure is made up in part of a non-histone chromosomal protein that in interphase cells can be detected only in the nucleus. Studies of this nuclear-mitotic apparatus protein (NuMA protein) are reported here. Monoclonal antibodies specific for the NuMA protein have been used in immunofluorescence studies to visualize the prenucleus-like polar structure and to identify the NuMA protein by immunoblotting after electrophoretic separation. The NuMA protein is a non-histone chromosomal protein of molecular weight 250000 relative to standard protein molecular weight markers in sodium dodecyl sulphate/polyacrylamide gel electrophoresis. Experiments are described that indicate several difficulties in studying the possible affinity and association of NuMA protein with mitotic chromosomes. Metaphase chromosomes isolated by the polyamine procedure of Lewis and Laemmli have bound NuMA protein detectable by immunofluorescence or by immunoblotting, but measurements made at different stages of chromosome purification show that most of the NuMA protein is separated from the chromosomes using this purification procedure. Chromosomes purified from mixtures of human and Chinese hamster cells (the latter have none of the human form of NuMA recognized by a monoclonal antibody) have human NuMA protein bound to the hamster chromosomes. Results suggest that in cell extracts exchange reactions of NuMA protein can occur, which must be avoided in the study of its natural function.

Animals↗

PubMed1983

Plasma levels and pharmacokinetics of norethindrone and ethinylestradiol administered in solution and as tablets to women.

Twenty-four normal adult female volunteers were dosed orally with a solution and tablet formulation containing the contraceptive combination of norethindrone (NET, 1.0 mg) and ethinylestradiol (EE2, 0.12 mg) in a crossover bioequivalence study. Blood was sampled sequentially following single oral doses and the plasma separated for analysis of NET and EE2 by specific radioimmunoassays. Comparisons of both drugs following a dose in solution and tablets were made with respect to the following parameters: (a) plasma concentrations at each sample time; (b) maximum plasma concentration (Cpmax); (c) time to maximum plasma concentration (Tmax); (d) total area under the plasma concentration vs. time curve (AUC), and (e) plasma half-life (t1/2). It was found that the tablet and solution doses were bioequivalent with respect to EE2 absorption. However, absorption of NET from solution and tablet doses exhibited significant differences with respect to plasma levels at certain time points as well as AUC (which were higher following the tablet dose), but Cpmax, Tmax and t1/2 were not significantly different. Pharmacokinetic analysis of both drugs following the tablet dose was carried out using a two-compartment open model. The absorption rate constant (ka) and peripheral to central compartment transfer rate constant (k21) were similar for NET and EE2, but statistically significant differences were observed with respect to the distribution rate constant (alpha), the central to peripheral transfer rate constant (k12), the overall elimination rate constant (ke1), and volume of distribution (V1/F). The elimination rate constant (beta) for both drugs showed a difference of borderline statistical significance.

Adolescent↗

PubMed1971