Cutaneous Estradiol Permeation, Penetration and Metabolism in Pig and Man

AIM AND METHODS

Drug development in dermatotherapy and also development of transdermal therapeutic systems (TTS) demand high-predictive in vitro models to estimate drug levels in skin and systemic uptake. Here we compare three ready-to-use models, reconstructed human epidermis, split porcine skin and the perfused porcine forelimb. 17beta-Estradiol (E(2)), which is highly metabolized by skin cells, serves as model drug since E(2) application is of high relevance in hormone replacement therapy while topical E(2) may promote wound healing. E(2) TTS, gel and an ethanolic solution were investigated for cutaneous penetration, permeation and metabolism.

RESULTS

E(2) TTS enabled an E(2) uptake of 42.9% of the applied dose accompanied by a high percentage of E(2) metabolism (30% of the penetrated dose) in the perfused porcine forelimb. In Franz cell experiments with reconstructed human epidermis and split porcine skin, the gel allowed an E(2) uptake of 41.7 and 22.9% of the applied dose accompanied by a high E(2) metabolism (42.6 and 28.6% of the penetrated dose). Due to toxic effects of the vehicle, this was not true with an ethanolic solution, then E(2) permeation and metabolism were clearly diminished. Most importantly, the in vitro models proved to be predictive with respect to the E(2)/estrone ratio in female plasma under transdermal hormone replacement therapy.

CONCLUSION

In vitro tests should reduce the need for both animal and human studies for cutaneous uptake and metabolism in the future.

Anti-genotoxic and free-radical scavenging activities of extracts from (Tunisian) Myrtus communis

The effect of extracts from leaves of Myrtus communis on the SOS reponse induced by Aflatoxin B1 (AFB1) and Nifuroxazide was investigated in a bacterial assay system, i.e. the SOS chromotest with Escherichia coli PQ37. Aqueous extract, the total flavonoids oligomer fraction (TOF), hexane, chloroform, ethyl acetate and methanol extracts and essential oil obtained from M. communis significantly decreased the SOS response induced by AFB1 (10 microg/assay) and Nifuroxazide (20 microg/assay). Ethyl acetate and methanol extracts showed the strongest inhibition of the induction of the SOS response by the indirectly genotoxic AFB1. The methanol and aqueous extracts exhibited the highest level of protection towards the SOS-induced response by the directly genotoxic Nifuroxazide. In addition to anti-genotoxic activity, the aqueous extract, the TOF, and the ethyl acetate and methanol extracts showed an important free-radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. These results suggest the future utilization of these extracts as additives in chemoprevention studies.

Preventing diseases of the prostate in the elderly using hormones and nutriceuticals

The prostate has only one function, namely to secrete fluid containing substances that are needed for reproduction. This requires an extremely high concentration of androgens in the tissues. Benign prostatic hypertrophy (BPH) seems to be related to the long-term exposure of the prostate to the strong androgen 5alpha-dihydrotestosterone (DHT) and, possibly, to estrogens. The relation between prostate cancer and androgens is suggested to be U-shaped, with both extremes of androgen concentrations being associated with increased risk of invasive cancer. In the treatment of patients with BPH, the lipidic liposterolic extracts of Serenoa repens were as effective as the pharmaceutical inhibitors of the 5alpha-reductase enzyme or alpha1-adrenergic blockers in relieving urinary symptoms. In addition to moderately inhibiting the 5alpha-reductase activity, Serenoa seems to exert anti-inflammatory and complementary cellular actions with beneficial effects on the prostate. Unlike the pharmaceutical 5alpha-reductase inhibitors, finasteride and dutasteride, Serenoa does not suppress serum PSA, facilitating the follow-up and the early detection of prostate cancer. We suggest a strategy to prevent prostate cancer that aims at providing men with partial androgen deficiency correct testosterone substitution with a sustained release buccal bio-adhesive tablet. In addition, food supplementation with extracts of Serenoa repens and a combination of the antioxidants selenium, (cis)-lycopene and natural vitamin E, together with fish oil rich in long-chain polyunsaturated essential fatty acids of the omega-3 group seems warranted. Clearly, a holistic approach including careful clinical and biological monitoring of the aging man and his prostate remains mandatory.

294EFFECTS OF LONG DAYLIGHT ON CAPRINE SCROTAL CIRCUMFERENCE AND SEMEN QUALITY

Seasonal variation of the reproductive activity of small ruminants in the southern USA is controlled by photoperiod. We tested the hypothesis that artificial manipulation of photoperiod has an effect on caprine testicular activity and semen quality. The objective of this study was thus to determine the effects of photoperiod on caprine scrotal circumference and semen parameters during the nonbreeding season. Ten Saanen and Alpine bucks, two to three years old, raised at the Small Ruminant Research and Extension Center of Fort Valley State University (latitude 32°37′ N, longitude 83°39′ W), were used in the study. Throughout the study, the bucks were fed a concentrate diet containing 16% crude protein, and 2.7 Mcal/Kg of digestible energy. Two groups of bucks randomly selected were exposed to long daylight (16L:8D; n=5) or ambient daylight (12L:12D, control;; n=5) for a period of three weeks during the month of March. Scrotal circumference measurements and semen collection were conducted on each buck twice a week for a total of five trials. Semen samples were collected using an artificial vagina and an electroejaculator. Samples were immediately transferred to the laboratory for further evaluation. Data were analyzed as a completely randomized design with repeated measures using SAS program (SAS, 1990). When means were significant by ANOVA (P<0.05), they were separated by least significant difference. Results are presented as the least square means±SEM. Long daylight did not affect semen volume (mL), % motility, sperm concentration (billions/mL), % viability, or % abnormality(P>0.05). However, semen motility, sperm concentration, and abnormality were influenced by treatment in trials 3, 1, and 5, respectively (P<0.05). The least square means±SEM values for these parameters were 35±15, 0.58±0.1, and 20.0±3.7 for long daylight-treated bucks v. 87±15, 0.13±0.1, and 7.8±3.7 for the control, respectively. Further, long daylight affected scrotal circumference (P<0.05). Scrotal circumferences were decreased in trials 1, 2, and 5 (P<0.05). Long daylight decreased scrotal circumference without affecting semen quality in this study.

Chronic prostatitis and male accessory gland infection--is there an impact on male infertility (diagnosis and therapy)?

The aim of this article was to discuss by means of a review of the literature and own study material the multifactorial aetiology of male infertility, extrapolate this hypothesis to male accessory gland infection (MAGI) and relate it to chronic prostatitis and its treatment. Infertility is a multifactorial disease and diagnosis and therapy must be oriented as such. Although the relationship between prostatitis and infertility remains unclear, bacteria, viruses, leucocytes, reactive oxygen species, cytokines, obstruction and immunological abnormalities must be seen as cofactors in the development of infertility in patients with MAGI and prostatitis. Infection, trauma, allergy, neurogenic damage, chemical or mechanical factors can lead to a long-lasting inflammation of the prostate or pelvic organs even after eradication of the aetiological agent, and is potentially related to infertility through cytokines. In relation to treatment of infertility, antibiotics play a role in bacterial prostatitis whereas in abacterial prostatitis other treatments like antioxidants, sacral nerve stimulation and anti-inflammatory treatment are worth to be studied in the future.

Quantitative descriptors of corneal topography that influence soft toric contact lens fitting

PURPOSE

Empirical soft toric contact lens fitting based on manifest refraction and keratometry often presents unanticipated fitting and power errors upon initial lens dispensing. However, corneal topography may provide features that influence soft toric lens performance, flexure, and back vertex power in situ, which may assist in improved fitting guidelines. In this study, quantitative topographic descriptors were generated and analyzed as potential variables in predicting soft toric fitting success.

METHODS

One hundred five eyes of 54 patients were empirically fit with back surface toric, prism ballasted, soft contact lenses after videokeratography was performed with the EyeSys 2000 (v. 4.0) or Humphrey Atlas (v. A6) instrument. Custom software was written to generate 54 separate quantitative descriptors of shape and astigmatism from the raw data files. A logistic regression was used to determine which variables significantly contributed to a successful or failed fit.

RESULTS

Two types of empirical fitting failures were identified: loose fit (n = 15) and power errors (n = 17). The following variables were associated with a fitting failure: flat simulated keratometry (SimKf2b) within the central 3 mm zone, steep simulated keratometry (SimKs2b) within the central 3 mm zone, a difference between central and peripheral flat meridian axis (DIFFAXIS), and a difference between central and peripheral astigmatism (DIFFASTIG). For fitting failures caused by power errors, a larger steep SimKs2b (p< 0.01) and smaller DIFFAXIS (p< 0.05) were associated with a failed fit. For failures caused by physical fit of a selected base curve, a smaller DIFFAXIS (p< 0.05), larger steep SimKs2b (p< 0.05), and larger DIFFASTIG (p< 0.01) were associated with a failed fit.

CONCLUSIONS

Novel quantitative descriptors of corneal shape and toricity derived from topography are associated with empirical soft toric contact lens fitting failures. Future algorithms or recommendations for improved soft toric lens selection may be derived from such indices to develop a predictive model for successful soft toric lens fitting using corneal topography data.

Fading renal hyperfiltration in children following liver transplantation

In a prospective longitudinal study, we investigated the renal function (RF) of 23 children before and after orthotopic liver transplantation (OLT). The aim was to assess both the outcome of pretransplant hyperfiltration and the clinical nephrotoxic effects of cyclosporin A (CsA); children with decreased RF prior to OLT were therefore excluded. The RF study of the 13 remaining patients included glomerular filtration rate (GFR) and effective renal plasma flow (RPF) measured by inulin (Cin: mL/min/1.73 m2) and para-amino hippurate (Cpah: mL/min/1.73 m2) clearances, respectively. Hyperfiltration prior to OLT was observed in six children, i.e. Cin>170 [range 172-230] and Cpah>800 [808-1,133]. A significant decrease in RF was noted as soon as 6 months after OLT: Cin (mean+/-SD)=107+/-23 vs. 158+/-46 (p<0.003); Cpah=583+/-119 vs. 791+/-243 (p<0.004). This was due to loss of hyperfiltration in the six children, as there was no significant difference in RF before and 6 months after OLT in the other seven children. With a 36-month follow-up, there was no correlation between CsA trough blood level and RF. In conclusion, following OLT, RF underwent early changes owing to loss of prior hyperfiltration in children without impaired RF before OLT. In addition, no evidence of CsA nephrotoxicity was found and RF remained stable during follow-up.

A comparative study of propolis and saline application on human dentin. A SEM study

The purpose of this study was to compare the texture changes of dentinal surfaces after the application of propolis and saline. Twenty-four recently extracted human premolar teeth were obtained from the Division of Oral and Maxillofacial Surgery, King Saud University, College of Dentistry, Riyadh. The teeth were classified as sound, periodontally involved and with recession. Forty-eight, 3 x 3 mm dentin disc specimens were prepared and only 24 specimens were treated with propolis (pH 8.5) and saline (pH 6). They were treated in 4 categories i.e.: (1) no application of any material (control); (2) propolis for 60 seconds; (3) propolis for 120 seconds and (4) saline for 60 seconds. All experimental specimens were burnished with cotton pellet with propolis and saline for the prescribed time. All specimens were prepared for scanning electron microscopy (SEM) with sputter technique, (Blomlof and Lindskog, 1995), and examined in the SEM (Jeol, Japan) operated at 25 KV with a tilt angle between 0-30 degrees. The bar was 10 mm and magnification 2000x. There were dentinal tubules occlusion in all three groups of dentin treated with propolis for 120 seconds. The propolis was better than saline in occluding dentinal tubules. It may be suggested that further research is needed for double blind clinical trials of propolis in patients with dentinal hypersensitivity.

[A strategy for the prevention of male infertility]

Since 1990 there has been a simultaneous reduction of natality in Flanders (by approximately 12%) with increased demand for assisted reproduction, while sperm quality, mostly motility and morphology, have clearly deteriorated over recent decades. This evolution has been ascribed to the deleterious effects of hormone disrupting substances in the environment, synergistically enhancing unfavorable influences from life style and possible genito urinary diseases that can impair the function of the testes and accessory sex glands. It is probable that this synergistic effect is exerted through the intermediate of free oxygen radicals (also called reactive oxygen species) that damage both the sperm membrane and sperm DNA, which could allow certain minimal inborn genetic defects (such as point lesions) to come to expression. Both pseudo- or xeno-estrogens (such as certain organo chlorides, alkyl phenols, phthalates, etc.) and anti-androgens are held responsible for prenatal testicular damage and increased prevalence of testicular carcinoma and oligozoospermia, for anatomical malformations, as well as postnatal depression of testicular function and spermatogenesis. However, methods presently available to detect hormone disrupters are tedious and not fully adequate. A first strategic goal is to develop a simple method for the detection of these substances so that environmental pollution can be mapped. Fazing out the production and application of hormone disrupters, and removing them from the environment are the second strategic step. Also, a health food is being developed that will inhibit the absorption of these chemicals from the intestinal tract. In addition it is projected to detect and treat common genital diseases that can cause infertility, such as varicocele and infection of the urinary tract and accessory sex glands. The first could be organized to take place during medical examinations at school, whereas the second requires correct medical treatment of any cysto urethritis in adolescents. Non surgical treatment of varicocele by means of transcatheter embolization offers a cost effective approach, with minimal risk and complications, and high level of efficacy. Improving food quality and educational efforts aimed at a healthier life style should score high priority. The suggested strategy uses several entries in order to address the multifactorial mechanisms involved in the pathogenesis of male infertility. Preliminary epidemiological and biological data suggest that the proposed strategy can, indeed, be successful within a relatively short lapse of time.

Homohemodialysis: a technique of dialysis for the uremic animal

As an alternative to kidney transplantation in conditions of renal failure, an in situ kidney of a healthy individual may be used. The present study utilizes the kidney of a healthy rabbit as a hemoperfusion unit for another, uremic, animal. The study comprised 17 experimental models, each of which consisted of 2 adult New Zealand rabbits. One animal of each model was rendered uremic by means of bilateral nephrectomy. The blood chemistry (urea, creatinine, sodium, potassium, pH and base deficit) was examined pre- and 4-hourly post-operatively. When after 48 hours post-nephrectomy, the blood chemistry had reached a level sufficient to endanger the animal's life, homohemodialysis was performed. The anticoagulated blood was circulated from the uremic animal to the normal one and then back to the uremic animal through the femoral vessels using a tube system. The blood chemistry was determined every 10 minutes and pH and base deficit every 30 minutes. All animals died or were sacrificed within 21 hours after shunting was started, and autopsy was done. Serum sodium was the first to normalize within the first 10 minutes post-shunting, followed by serum potassium and pH in 30 minutes. Blood urea and creatinine reached normal levels in 40 minutes and base deficit in 60 minutes post-shunting. The pathologic examination of specimens from the vital organs of both the normal and uremic animals showed different degrees of cellular damage probably due to hypotension or acute effects of the unbalanced animal homeostasis. The cellular damage was much less in the normal than in the uremic animals. In conclusion, homohemodialysis proved to be effective in normalizing the concentrations of the different substances retained in the blood of uremic animals within only 60 minutes of dialysis.

Laparoscopic control of bleeding liver laceration

The role of laparoscopy in the management of solid-organ intraabdominal injuries has still not been fully elucidated. The following is a case report of successful laparoscopic control of a bleeding liver laceration, grade III (following CT-guided liver biopsy), after unsuccessful attempts at angiographic embolization.

Mechanisms of sperm deficiency in male accessory gland infection

The presence of 2 million or more peroxidase-positive white blood cells per ml of semen, or the diagnosis of male accessory gland infection, is associated with important biochemical and biological changes in semen plasma and in the spermatozoa, reducing their fertilizing potential in vitro and in vivo (e.g., during intra-uterine insemination). In addition to the effects of reactive oxygen species, and its influence on the essential fatty acid composition of the sperm membrane, potentially unfavourable effects can occur through the intermediate of increased concentrations of certain cytokines, and decreased activity of enzymes such as alpha-glucosidase. In contrast, lower numbers of white blood cells may exert beneficial effects on spermatozoa thanks to the increased production of hepatocyte growth factor/scatter factor (a tissue repairing substance), and the stimulation of immuno-competent cells by particular cytokines (e.g., Interleukin-6).

Axial vibration of threaded external fixation pins: detection of pin loosening

The hypothesis of this study was that a nondestructive vibrational method could detect bone lysis at the external fixation pin-bone interface prior to current clinical and radiographic methods. In vitro models were used to simulate changes observed during pin loosening in vivo. Fixation pin axial natural frequency decreased with decreasing tensile modulus of the material into which it was implanted. In a live animal study the right tibia of 12 dogs was fractured and stabilized with a four-pin unilateral external fixation frame. The axial natural frequency of each pin was measured and radiographs were taken at 0, 2, 4, 6, 8, and 10 weeks after surgery. The natural frequency did not change when the first radiographic changes around the interface were observed. Pins were palpably stable at this point. As loosening progressed, the natural frequency did decrease. Frequency and quasistatic tests of dissected pin-bone structures revealed a good correlation between natural frequency and pin-bone interface stiffness. In addition, the measurement of natural frequency was more sensitive to bone structure changes at the pin-bone interface than low-load quasi-static stiffness. Therefore, a nondestructive vibration technique could be used instead of low-load quasistatic tests for assessing the pin-bone interface ex. vivo.