Optimizing delivery of therapeutics: percutaneous technologies.

The purpose of this communications is to 1) demonstrate the potential of percutaneous drug-delivery on the example of female reproductive steroids, 2) point out the differences between transdermal and conventional drug dosing, and 3) outline new technologies and innovations that are looming on the horizon, specifically in the area of pain control. Transdermal delivery systems are of two basic types. The first ones employ principles of passive diffusion, and they are used for hormonal replacement therapy (HRT) and contraception. Patches for HRT, designed to release estradiol (E2) only, require a simultaneous dosing with oral progestogens. Patches employing both E2 and a progestogen release the combination either continuously or sequentially. In the latter method, estrogen-only patches are applied for 14 days, followed by a 14-day application of patches releasing both hormones. Both methods successfully cope with symptoms and signs of menopause, including bone loss. Contraceptive transdermal patches deliver ethinylestradiol in combination with the progestogen norelgestromin. This system provides high contraceptive protection with predictable withdrawal bleeding and without major adverse events and weight changes. Hormones delivered by the skin avoid first-pass liver metabolism. Other advantages include rapid onset and termination of action, self-administration, and attainment of therapeutic hormone levels with low daily doses. A disadvantage is the variable intra- and inter-individual percutaneous absorption. In some patients, patches can cause skin irritation. Active systems deliver therapeutics across intact skin non-invasively by means of an electric potential (electrotransport). A system consisting of tooth-like titanium microprojections that penetrate only the keratinized epidermis facilitates painless and needle-free transport of complex molecules to the capillaries of the dermis. Other devices use low frequency ultrasound. These systems enable precise dosage, delivery of large molecules, such as growth hormone and vaccines, and dosing of analgesics "on demand". Novel transdermal technologies are profoundly changing the current methods of pain management. (Fig. 6, Ref. 47.).

Safety of factor VIII inhibitor bypass activity (FEIBA): 10-year compilation of thrombotic adverse events.

Published and unpublished spontaneously reported thrombotic adverse events (AEs) in factor VIII inhibitor bypass activity (FEIBA(R)) recipients were compiled for the most recent 10-year period during which FEIBA(R) units equivalent to 3.95 x 105 typical infusions were distributed worldwide. A total of 16 thrombotic AEs were documented over the 10-year period, corresponding to an incidence of 4.05 per 105 infusions (95% CI, 2.32-6.58 per 105 infusions). Disseminated intravascular coagulation (n=7) and myocardial infarction (n=5) were the most frequent thrombotic AEs. One fatality occurred in an 87-year-old metastatic cancer patient. In 13/16 (81%) patients known risk factors were present, most commonly FEIBA(R) overdose in 8/16 (50%), obesity in 3/16 (19%) and serum lipid abnormalities in 2/16 (12%). These findings indicate that thrombotic AEs in FEIBA(R) recipients are very rare. Recognition of risk factors and avoidance of FEIBA(R) overdosage may avert thrombotic AEs.

Norgestimate. From the laboratory to three clinical indications.

This review of preclinical studies and clinical trials of efficacy and safety examines the relation between structure and function in the norgestimate (NGM) molecule, describes the pharmacologic characteristics of NGM and evaluates clinical experience with NGM in oral contraception (OC), treatment of hyperandrogenism in women and hormonal replacement therapy (HRT). NGM is a progestin of the 19-norsteroid series with an oxime group on C-3. In women, only low serum levels of NGM can be detected for five hours after ingestion. NGM is swiftly converted into its main metabolite, the 17-deacetylated norgestimate (norelgestromin), which carries the progestogenic properties of NGM. The metabolite reaches a mean peak concentration of 3,500 pg/mL 1.5 hours after intake and has a half-life of > 24 hours. The progestogenic potency of NGM and its main metabolite is comparable to that of progesterone. The doses of NGM in OCs effectively inhibit ovulation and control uterine bleeding. In the triphasic NGM/ethinyl estradiol (EE) OC, the total monthly load of progestin is only 4.5 mg. NGM has a low androgenic impact and does not interfere with the positive metabolic actions of estrogens, notably the estrogen-induced increase in high-density lipoprotein levels. OCs with NGM and EE increase the serum concentration of sex hormone binding globulin threefold, augmenting the binding of circulating testosterone and reducing free testosterone levels by 50%. Consequently, OCs with NGM are therapeutic for hyperandrogenic symptoms, such as acne. In a new type of HRT three-day dosing with 17 beta-estradiol (E2) alone is followed by three-day dosing with E2 plus NGM. This regimen treats vasomotor symptoms, protects the endometrium from hyperproliferation and is associated with a favorable lipid profile. NGM is a versatile progestin suitable for medical use from adolescence through the reproductive years to menopause.

OCP1, an F-box protein, co-localizes with OCP2/SKP1 in the cochlear epithelial gap junction region.

Immunohistochemical data indicate that OCP1 co-localizes exactly with OCP2 in the epithelial gap junction region of the guinea pig organ of Corti (OC). Despite the abundance of OCP1 in the OC, gaining access to its coding sequence -- and, in particular, the 5' end of the coding sequence -- proved unexpectedly challenging. The putative full-length OCP1 cDNA -- 1180 nucleotides in length -- includes a 67 nucleotide 5' leader sequence, 300 codons (including initiation and termination signals), and a 216 nucleotide 3' untranslated region. The cDNA encodes a protein having a predicted molecular weight of 33,700. The inferred amino acid sequence harbors an F-box motif spanning residues 52--91, consistent with a role for OCP1 and OCP2 in the proteasome-mediated degradation of select OC proteins. Although OCP1 displays extensive homology to an F-box protein recently cloned from rat brain (NFB42), clustered sequence non-identities indicate that the two proteins are transcribed from distinct genes. The presumptive human OCP1 gene was identified in the human genome databank. Located on chromosome 1p35, the inferred translation product exhibits 94% identity with the guinea pig OCP1 coding sequence.

[The health care revolution in the USA]. / Zdravotnícka revolúcia v USA.

The changes in medical care in the USA have not been completed yet. The government which will be established after the following presidential elections will be compelled to deal with the organisation of medical care in order to make the financial participation of the federal government manageable. The American medical workers must unite in their procedures in order to bring the negotiations with the government institutions, insurers and health maintaining institutions to a successful end. The struggle for medical independence is of great importance as it enables to suppress stereotypes and obsolete traditions, and leads to innovative procedures which represent the basis for progress in medical science. (Fig. 10, Ref. 16.)

The dihydrolipoyl acyltransferase (BCE2) subunit of the plant branched-chain alpha-ketoacid dehydrogenase complex forms a 24-mer core with octagonal symmetry.

Little is known of the plant branched-chain alpha-ketoacid dehydrogenase complex. We have undertaken a detailed study of the structure of the dihydrolipoyl acyltransferase (BCE2) subunit that forms the core of the complex, to which two other enzymes attach. Mature Arabidopsis thaliana BCE2 was expressed in Escherichia coli. The soluble recombinant protein was purified using a Superose 6 size-exclusion column to >90% homogeneity and was catalytically active. The recombinant protein formed a stable complex with a native molecular mass of 0.95 MDa and an S coefficient of 19.4, consistent with formation of a 24-mer. Negative-staining transmission electron microscopy of the recombinant protein confirmed that BCE2 forms a core with octagonal symmetry. Despite divergence of mammalian and plant BCE2s, there is clearly conservation of structure that is independent of primary sequence.

Influence of monovalent cations on rat alpha- and beta-parvalbumin stabilities.

The mammalian genome encodes both alpha- and beta-parvalbumin isoforms. The rat beta-parvalbumin (aka "oncomodulin") is more stable than the alpha isoform at physiological pH and ionic strength, despite its substantially higher charge density and truncated C-terminal helix [Henzl, M. T., and Graham, J. S. (1999) FEBS Lett. 442, 241-245]. Reasoning that solvent interactions could contribute to this unexpected finding, we have examined the stabilities of the Ca(2+)-free alpha- and beta-parvalbumins as a function of Na(+) and K(+) concentration. Differential scanning calorimetry data suggest that, at physiological pH and ionic strength, the beta isoform binds roughly 2 equiv of Na(+) or a single equivalent of K(+) with moderate affinity. Under comparable conditions, the alpha isoform apparently binds just 1 equiv of Na(+) and essentially no K(+). Isothermal titration calorimetry experiments suggest that the bound monovalent ions occupy the EF-hand motifs. In 0.15 M K(+), at pH 7.4, the stability of the apo-beta-parvalbumin exceeds that of the alpha isoform by approximately 2.6 kcal/mol at 37 degrees C and by approximately 3.0 kcal/mol at 25 degrees C. The latter value represents a substantial fraction of the difference in Ca(2+)-binding free energies measured in vitro for the two proteins. Significantly, however, these results do not completely explain the paradoxical stability of the beta isoform, which maintains its higher melting temperature under all conditions examined.

The alpha and beta subunits of the GA-binding protein form a stable heterodimer in solution. Revised model of heterotetrameric complex assembly.

We have studied the assembly of GA-binding protein (GABP) in solution and established the role of DNA in the assembly of the transcriptionally active GABPalpha(2)beta(2) heterotetrameric complex. GABP binds DNA containing a single PEA3/Ets-binding site (PEA3/EBS) exclusively as the alphabeta heterodimer complex, but readily binds as the GABPalpha(2)beta(2) heterotetramer complex on DNA containing two PEA3/EBSs. Positioning of the PEA3/EBSs on the same face of the DNA helix stabilizes heterotetramer complex binding. These observations suggest that GABPalphabeta heterodimers are the predominant molecular species in solution and that DNA containing two PEA3/EBSs promotes formation of the GABPalpha(2)beta(2) heterotetrameric complex. We analyzed the assembly of GABPalpha(2)beta(2) heteromeric complexes in solution by analytical ultracentrifugation. GABPalpha exists as a monomer in solution while GABPbeta exists in a monomer-dimer equilibrium (K(d) = 1.8 +/- 0.27 microM). In equimolar mixtures of the two subunits, GABPalpha and GABPbeta formed a stable heterodimer, with no heterotetramer complex detected. Thus, GABP exists in solution as the heterodimer previously shown to be a weak transcriptional activator. Assembly of the transcriptionally active GABPalpha(2)beta(2) heterotetramer complex requires the presence of specific DNA containing at least two PEA3/EBSs.

Butoconazole nitrate 2% for vulvovaginal candidiasis. New, single-dose vaginal cream formulation vs. seven-day treatment with miconazole nitrate. Gynazole 1 Study Group.

OBJECTIVE: To compare the safety and efficacy of a single vaginal dose of a butoconazole nitrate 2% bioadhesive, sustained-release cream* (butoconazole 1-BSR) with a seven-day schedule of miconazole nitrate vaginal cream 2% (miconazole 7). STUDY DESIGN: The clinical trial was conducted according to a randomized, parallel, investigator-blind, multicenter study design. The patients self-administered the respective creams to the posterior vaginal fornix. Two hundred twenty-three patients started the trial and were analyzed for safety. A total of 205 patients qualified for efficacy analysis, 101 receiving butoconazole 1-BSR and 104 using miconazole 7. Patients receiving butoconazole 1-BSR inserted one applicator full of medication once. Those assigned to receive miconazole 7 inserted one applicator full daily for seven days. Patients were evaluated 7-10 and 30 days after completion of therapy. RESULTS: Butoconazole 1-BSR rapidly relieved the signs and symptoms of vulvovaginal candidiasis. The proportion of patients with severe symptoms declined from the pretreatment 20% to 6% on the 1st day, to 3% on the 4th day, and to 2-1% on the 5th-7th day after single-dose application. Eight to ten days after treatment completion, clinical symptoms regressed in 92%, and fungal cultures were negative in 87% of patients. At the 30-day posttreatment visit, 88% of patients remained clinically cured, and 74% had negative fungal cultures. In the miconazole 7 group, the proportion of patients with severe symptoms declined from 23% to 19% after the first dose; thereafter, symptom relief proceeded more rapidly. Eight to ten days after treatment completion, clinical symptoms regressed in 92% and fungal cultures were negative in 87% of patients. At the 30-day follow-up examination, 86% patients were clinically cured, and 77% were culture negative. After single-dose butoconazole 1-BSR, severe symptoms receded faster than after the first dose of miconazole 7, and the difference was statistically significant (P = .01). In all other efficacy parameters, the differences between the two groups were not statistically significant. Neither treatment regimen caused significant adverse events. CONCLUSIONS: This clinical trial demonstrated that butoconazole 1-BSR is an effective and safe alternative to longer-term therapy with miconazole nitrate (seven days) for vulvovaginal candidiasis.

Conformational stabilities of the rat alpha- and beta-parvalbumins.

It is widely believed that beta-parvalbumin (PV) isoforms are intrinsically less stable than alpha-parvalbumins, due to greater electrostatic repulsion and an abbreviated C-terminal helix. However, when examined by differential scanning calorimetry, the apo-form of the rat beta-PV (i.e. oncomodulin) actually displays greater thermal stability than the alpha-PV. Whereas the melting temperature of the a isoform is 45.8 degrees C at physiological pH and ionic strength, the Tm for the beta isoform is more than 7 degrees higher (53.6 degrees C). This result suggests that factors besides net charge and C-terminal helix length strongly influence parvalbumin conformational stability. Extension of the F helix in the beta-PV, by insertion of Ser-109, has a modest stabilizing effect, raising the Tm, by 1.1 degrees. Truncation of the alpha-PV F helix, by removal of Glu-108, has a more profound impact, lowering the Tm by 4.0 degrees.

Reproductive medicine in the second half of the 20th century.

This communication reviews the most important achievements of human reproductive medicine during the last 50 years. The progress in this discipline has been so profound and unexpected that it has raised ethical questions of a fundamental character. Over the last 50 years of this century, new insight into reproductive processes enabled the following development: hormonal contraception, gonadotropin-releasing hormone (GnRH) and its agonistic and antagonistic analogues, prostaglandins: induction of labor and conquering dysmenorrhea, selective estrogen receptor modulators (SERM), assisted reproductive technologies (ART), and recombinant DNA technology and cloning. Currently, safe and effective contraceptive methods are available. Control of the world population growth is not a medical issue anymore: it is a political and social problem. Governments, and national and ideological leaders must share the responsibility for creating a social and economic milieu that facilitates women's education, provides access to birth control methods, and motivates the population to limit its own growth. At the same time, society must foster traditional family and moral values Vis a Vis sex. (Fig. 6, Ref. 22.)

Periovarian peritoneal adhesions in women with endometriosis. Structural patterns.

OBJECTIVE: To draw attention to the structural features of adhesions associated with pelvic endometriosis since they are less well studied than endometriosis proper. STUDY DESIGN: Sixty-two samples of periovarian adhesions were laparoscopically obtained from 24 infertile women 26-38 years of age and were prepared for detailed histologic analyses. RESULTS: Macroscopically, the adhesions were either velamentous or cordlike and grossly were free of endometriosis. Most adhesions were attached to the connective tissue of the ovarian tunica albuginea; in two cases they were attached to the corpus luteum. Upon microscopic analysis, velamentous adhesions consisted of fibrous sheets of collagen connective tissue, with the surface lined with single-layered coelomic epithelium. The cord-like adhesions consisted of "hyalinized" fibrous tissue and were either avascular or vascularized. Irregular cystic or tubular structures that could be regarded as endometriosis were found in four patients. Hyaline cartilage within the tissue of the adhesion was an unexpected finding in one patient. CONCLUSION: Microscopic analysis permitted grouping of the adhesions in the following way: (1) Connective tissue adhesions (23 patients) with the following subcategories: (A) fibrous, either avascular or encompassing degenerating blood vessels (6 patients); (B) vascularized, containing granulomatous tissue (12 patients); (C) vascularized with stromoglandular endometrioid cysts or tubules (4 patients); (D) rare types, such as that encompassing hyaline cartilage (1 patient). (2) Fibrin adhesions (1 patient). From the clinical point of view, the presence of endometrial tissue within adhesions raises the question of whether there is a need for removal, rather than just lysis, of adhesions to avoid persistent pain.

Human issues and medical economics of endometriosis. Three- vs. six-month GnRH-agonist therapy.

OBJECTIVE: To project the efficacy and economic consequence of short-term intranasal gonadotropin-releasing hormone agonist (GnRH-a) for diagnosis of and therapy for endometriosis. STUDY DESIGN: Multicenter, placebo-controlled clinical trials of GnRH-a comparing three vs. six months of treatment, three months of retreatment and three months of postoperative treatment for the symptoms and signs of laparoscopically diagnosed endometriosis. RESULTS: The reduction in symptoms and signs of endometriosis was similar at the end of three months to the relief at six months. Retreatment was as effective as initial treatment, and the return of symptoms after laparoscopic surgery plus postoperative treatment for three months was delayed by approximately 18 months as compared to surgery alone. The projected charges for the surgical approaches (laparoscopy or minilaparoscopy) to diagnosis and therapy were 50-60% greater than those for the medical approach. CONCLUSION: GnRH-a administration for three months could be a cost-effective approach to the presumptive diagnosis and treatment of endometriosis among women with chronic pelvic pain.

Interconversion of the ligand arrays in the CD and EF sites of oncomodulin. Influence on Ca2+-binding affinity.

The parvalbumin metal ion-binding sites differ at the +z and -x residues: Whereas the CD site employs serine and glutamate (or aspartate), respectively, the EF site employs aspartate and glycine. Although frequently indistinguishable in Ca2+- and Mg2+-binding assays, the CD and EF sites nonetheless exhibit markedly different preferences for members of the lanthanide series [Williams et al. (1984) J. Am. Chem. Soc. 106, 5698-5702], underscoring an intrinsic nonequivalence. This nonequivalence reaches its pinnacle in the mammalian beta-parvalbumin (oncomodulin). Whereas the oncomodulin EF site exhibits the expected Ca2+/Mg2+ signature, the Ca2+ affinity of the CD site is severely attenuated. To obtain insight into the structural factors responsible for this reduction in binding affinity, oncomodulin variants were examined in which the CD and EF site ligand arrays had been exchanged. Our data suggest that binding affinity may be dictated either by ligand identity or by the binding site environment. For example, the Ca2+ affinity of the quasi-EF site resulting from the combined S55D and D59G mutations is substantially lower than that of the authentic EF site. This finding implies that other local environmental variables (e.g., binding loop flexibility, electrostatic potentials) within the CD binding site supersede the influence of ligand identity. However, the CD site ligand array does not acquire a high-affinity signature when imported into the EF site, as in the D94S/G98D variant. Instead, it retains its Ca2+-specific signature, implying that this constellation of ligands is less sensitive to placement within the protein molecule. The D59G and D94S single mutations substantially lower binding affinity, consistent with removal of a liganding carboxylate. By contrast, the S55D and G98D mutations substantially increase binding affinity, a finding at odds with corresponding data collected on model peptide systems. Significantly, the Ca2+ affinity of the oncomodulin CD site is increased by mutations that weaken binding at the EF site, indicating a negatively cooperative interaction between the two sites.

OCP2 exists as a dimer in the organ of Corti.

OCP2 is one of the most abundant proteins in the organ of Corti (OC), comprising approximately 5% of the total protein in the supporting cell population. Although the very close homolog, Skp1p, has been implicated in regulating cell-cycle progression, the function of OCP2 in the terminally differentiated cochlea is presently unknown. We have purified recombinant OCP2 from Escherichia coli and examined the protein by analytical ultracentrifugation. Interestingly, sedimentation equilibrium data collected at 20 degrees C unequivocally indicate that, at the concentrations present in the OC, free OCP2 would exist as a dimeric species. The apparent sedimentation coefficient is independent of concentration at loading concentrations between 10 and 100 microM, indicating the absence of a significant monomer-dimer equilibrium in this concentration range. The functional significance of this finding is discussed.

Oncomodulin is expressed exclusively by outer hair cells in the organ of Corti.

Oncomodulin (OM) is a small, acidic calcium-binding protein first discovered in a rat hepatoma and later found in placental cytotrophoblasts, the pre-implantation embryo, and in a wide variety of neoplastic tissues. OM was considered to be exclusively an oncofetal protein until its recent detection in extracts of the adult guinea pig's organ of Corti. Here we report that light and electron microscopic immunostaining of gerbil, rat, and mouse inner ears with a monoclonal antibody against recombinant rat OM localizes the protein exclusively in cochlear outer hair cells (OHCs). At the ultrastructural level, high gold labeling density was seen overlying the nucleus, cytoplasm, and the cuticular plate of gerbil OHCs. Few, if any, gold particles were present over intracellular organelles and the stereocilia. Staining of a wide range of similarly processed gerbil organs failed to detect immunoreactive OM in any other adult tissues. The mammalian genome encodes one alpha- and one beta-isoform of parvalbumin (PV). The widely distributed alpha PV exhibits a very high affinity for Ca2+ and is believed to serve as a Ca2+ buffer. By contrast, OM, the mammalian beta PV, displays a highly attenuated affinity for Ca2+, consistent with a Ca2+-dependent regulatory function. The exclusive association of OM with cochlear OHCs in mature tissues is likely to have functional relevance. Teleological considerations favor its involvement in regulating some aspect of OHC electromotility. Although the fast electromotile response of OHCs does not require Ca2+, its gain and magnitude are modulated by efferent innervation. Therefore, OM may be involved in mediation of intracellular responses to cholinergic stimulation, which are known to be Ca2+ regulated. (J Histochem Cytochem 46:29-39, 1998)

Nafarelin vs. leuprolide acetate depot for endometriosis. Changes in bone mineral density and vasomotor symptoms. Nafarelin Study Group.

OBJECTIVE: To compare intranasal nafarelin and intramuscular leuprolide acetate (LA) depot in the management of endometriosis. STUDY DESIGN: A multicenter, prospective, randomized, double-placebo, double-blind study was conducted on subjects who had symptoms and signs of endometriosis and bone mineral density (BMD) within the age-appropriate normal range. For 6 months, 99 subjects received nafarelin, 200 micrograms twice daily, and placebo injections once monthly; 93 subjects received LA depot injections, 3.75 mg once monthly, and placebo nasal spray, twice daily. Subjects were followed throughout treatment and for six months after treatment. The main outcome measures were changes in endometriosis symptoms and signs, BMD measurements, subject-reported and objectively measured hot flushes and circulating estradiol concentrations. RESULTS: Nafarelin was as effective as LA depot in alleviating symptoms and signs of endometriosis. LA depot recipients lost significantly more BMD, had more days with subjective hot flushes and more objectively measured hot flushes than did nafarelin recipients. In the nafarelin group, estradiol levels were consistently higher than in the leuprolide depot group, with significant differences by month 3 of dosing. CONCLUSION: Nafarelin and LA depot were equally effective despite higher estradiol levels in nafarelin recipients. Nafarelin-treated subjects lost less BMD, had fewer days with hot flushes and had fewer objectively measured hot flushes.