Polyphenolic-modified cellulose acetate membrane for bone regeneration through immunomodulation

To enhance the bioactivity of cellulosic derivatives has become an important strategy to promote their value for clinical applications. Herein, protocatechualdehyde (PCA), a polyphenolic molecule, was used to modify a cellulose acetate (CA) membrane by combining with metal ions to confer an immunomodulatory activity. The PCA-modified CA membrane has shown a significant radical scavenging activity, thereby suppressed the inflammatory response and created a favorable immune microenvironment for osteogenesis and mineralization. Moreover, addition of metal ions could further stimulate the osteogenic differentiation of stem cells and accelerate bone regeneration both in vitro and in vivo. This study may provide a strategy to promote the immunomodulatory activity of cellulose-based biomaterials for bone regeneration.

Polymeric antibacterial materials: design, platforms and applications

Over the past decades, the morbidity and mortality caused by pathogen invasion remain stubbornly high even though medical care has increasingly improved worldwide. Besides, impacted by the ever-growing multidrug-resistant bacterial strains, the crisis owing to the abuse and misuse of antibiotics has been further exacerbated. Among the wide range of antibacterial strategies, polymeric antibacterial materials with diversified synthetic strategies exhibit unique advantages (e.g., their flexible structural design, processability and recyclability, tuneable platform construction, and safety) for extensive antibacterial fields as compared to low molecular weight organic or inorganic antibacterial materials. In this review, polymeric antibacterial materials are summarized in terms of four structure styles and the most representative material platforms to achieve specific antibacterial applications. The superiority and defects exhibited by various polymeric antibacterial materials are elucidated, and the design of various platforms to elevate their efficacy is also described. Moreover, the application scope of polymeric antibacterial materials is summarized with regard to tissue engineering, personal protection, and environmental security. In the last section, the subsequent challenges and direction of polymeric antibacterial materials are discussed. It is highly expected that this critical review will present an insight into the prospective development of antibacterial functional materials.

pH-sensitive ternary nanoparticles for nonviral gene delivery

In this study, a ternary DNA delivery system with the charge conversional ability by deshielding the PEG layer at tumor acidity was designed.

Apoptosis induced by droloxifene and C-myc, Bax, Bcl-2 protein expression in corpus luteum of pregnant rats

AIM

To investigate the effects of droloxifene on apoptosis of luteal cells in pregnant rats, and analyze the possible relationships between the expression of C-myc, Bax, Bcl-2 protein in corpus luteum and apoptosis of luteal cells induced by droloxifene.

METHODS

Pregnant rats were treated orally with droloxifene 20 mg . kg-1 on d 2. Ovaries were collected on d 4 or d 8 for detecting the apoptosis of luteal cells by hematoxylin-eosin staining and terminal deoxyribonucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL), and observing the expression of C-myc, Bax, Bcl-2 protein in corpus luteum by immunohistochemistry. The ovarian fresh weight, protein contents, and serum progesterone levels were also determined on d 4 and d 8.

RESULTS

Apoptotic luteal cells appeared on d 4 and more apoptotic cells could be observed on d 8 in droloxifene treated rats. The ovarian fresh weight, protein contents, and serum progesterone concentration were found to be decreased significantly on d 8 as compared to the control group. In corpus luteum of droloxifene treated rats, the increased expression of C-myc and Bax protein could be observed on d 4 and d 8, respectively, whereas no obvious changes could be found in the expression of Bcl-2 protein.

CONCLUSION

Droloxifene could induce apoptosis of luteal cells of preimplantation in pregnant rats. An increased expression of C-myc protein and Bax/Bcl-2 ratio could be induced by droloxifene, which might be associated with the mechanisms of apoptosis of luteal cells induced by droloxifene.

Effects of droloxifene on apoptosis and Bax, Bcl-2 protein expression of luteal cells in pseudopregnant rats

AIM

To study the effects of droloxifene on apoptosis and the expression of Bax and Bcl-2 protein in corpus luteum of pseudopregnant rats.

METHODS

HE staining was used to examine the histological changes of ovaries. Apoptosis detection in situ was performed with TUNEL method. Expression of Bax and Bcl-2 protein was observed by immunohistochemistry analysis.

RESULTS

Apoptosis of luteal cells during the spontaneous regression of corpus luteum of pseudopregnant rats appeared on d 13 of pseudopregnancy, and the marked increase of apoptotic luteal cells could be observed on d 15. When pseudopregnant rats were treated with droloxifene 20 mg . Kg on d 2, apoptosis of luteal cells could be observed on d 8 and the duration of pseudopregnancy could be shortened from (15.5 +\- 1.1) d to (12.8 +\- 1.6) d. In pseudopregnant rats, the expression of Bax and Bcl-2 protein was found in the cytoplasm of luteal cells. However, no obvious differences in the intensity or localization could be found during various days of the pseudopregnancy, while an increase in Bax and a decrease in Bcl-2 protein expression could be induced by droloxifene treatment.

CONCLUSION

Droloxifene could facilitate apoptosis of luteal cells in pseudopregnant rats and shorten the period of pseudopregnancy. An increased Bax/Bcl-2 ratio might be involved in the facilitation of apoptosis induced by droloxifene in corpus luteum of pseudopregnant rats.

Inhibitory effect of nomegestrol acetate on steroidogenesis of cultured granulosa cells from rat ovary in vitro

AIM

To study the effect of nomegestrol acetate, a new synthetic progesterone on granulosa cells' viability and steroidogenesis function.

METHODS

Granulosa cells were cultured in McCoy's 5A medium. Trypan blue stain was used to measure viable cells. FSH and testosterone were added to stimulate the steroid secretion. Specific RIA assay was used to evaluate the estrogen and progesterone secretion respectively.

RESULTS

IC50 of nomegestrol acetate to damage cells is 6.85 mg/L (95 % confidence limits 5.36-8.75 mg/L). Nomegestrol acetate 0.45, 0.9, and 1.8 mg/L greatly inhibited the estrogen secretion from granulosa cells by 7.6 %, 12.5 %, 28.3 % in the presence of testosterone 0.5 micromol/L and FSH 10 U/L without affecting the number of viable cells. The secretion of progesteron were markedly decreased by 44.5 %, 53.3 %, and 62.0 % concurrently.

CONCLUSION

Nomegestrol acetate directly inhibited the steroidogenesis of granulosa cells.

Apoptosis induced by droloxifene and c-myc, bax and bcl-2 mRNA expression in cultured luteal cells of rats

Droloxifene is a tamoxifen derivative whose effects in the therapy of human breast cancer and postmenopausal osteoporosis have been studied widely. We had found that droloxifene could induce apoptosis of luteal cells of rat in vitro, but its mechanisms were unknown. In the present study, the expression of c-myc, bax and bcl-2 mRNA in cultured rat luteal cells during apoptosis induced by droloxifene was investigated and possible associations between these genes and apoptosis were analyzed. Cultured luteal cells of rats were incubated with droloxifene at various concentrations and with treatment durations. Occurrence of apoptosis was detected by terminal deoxyribonucleotidyl tranferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL), DNA staining and DNA electrophoresis. Expression of these genes' mRNA was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the c-myc and bax mRNA levels increased as concentrations or treatment durations of droloxifene increased, while the bcl-2 mRNA level exhibited no changes. A marked increase of c-myc and bax mRNA appeared respectively with 12 and 24 h of treatment, while a clear increase of apoptosis of luteal cells was found at 18 h. These results suggested that droloxifene could induce apoptosis of luteal cells of rat in vitro. The increase of c-myc mRNA expression might be one of the initiating factors and the elevated ratio of bax/bcl-2 mRNA was also probably involved in this effect.

Low dose gossypol for male contraception

AIM

To ascertain whether the side effects of gossypol, hypokalemia and irreversibility, could be avoided on dose reduction.

METHODS

Seventy-seven male volunteers were divided into 3 groups: control (22 cases), 10 mg gossypol (29 cases) and 12.5 mg (26 cases). Serum levels of testosterone, FSH and LH were measured by RIA and potassium by flame photometry. Sperm counts and motility were examined before and regularly after treatment for the evaluation of contraceptive efficacy.

RESULTS

The average sperm density and motility started to decrease significantly by the end of month 2 of medication and gradually reached the infertility levels (< 4 million/mL) in both treated groups. After that the 10 mg group was asked to take the same dose every other day for up to a total observation period of 16-18 months for the maintenance of infertility. Subjects in the 12.5 mg group did not take gossypol any more so as to observe the length of the loading dose required, but in a few, a maintenance dose of 12.5 mg every other day was instituted for a few more months. In both treated groups, none of the spouses was pregnant during the maintenance dose period. Serum levels of potassium, FSH, LH and testosterone were not significantly changed and not a single volunteer complained of myoasthenia. After cessation of drug administration, the semen data returned to pretreatment levels.

CONCLUSION

A regimen with 10 or 12.5 mg of gossypol as the daily loading dose and 35 or 43.75 mg as the weekly maintenance dose could induce infertility in male volunteers without developing hypokalemia or irreversibility.

[Genetic epidemiologic study of mitochondrial DNA 7445A-->G mutation among non-syndromic deafness in Chinese population]

OBJECTIVE

To study the Mitochondrial DNA 7445A-->G mutation in nonsyndromic deafness patients in Chinese population.

METHOD

Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to screen the mitochondrial DNA 7445A-->G mutation among 128 nonsyndromic deafness individuals from 32 pedigrees, 135 sporadic nonsyndromic deafness patients and 100 normal subjects.

RESULT

The 7445A-->G mutation did not appear in the experiment.

CONCLUSION

Incidence of the mitochondrial 7445A-->G mutation was lower than that of mtDNA 1555A-->G mutation in nonsyndromic deafness patients in China.

Gossypol blood levels and inhibition of spermatogenesis in men taking gossypol as a contraceptive. A multicenter, international, dose-finding study

The safety and efficacy of gossypol continues to be controversial. The aim of this study was to evaluate gossypol as a contraceptive pill for men at doses lower than those previously prescribed and in men from various ethnic origin. A total of 151 men from Brazil, Nigeria, Kenya, and China were divided into two groups. Both groups received 15 mg gossypol/day for 12 or 16 weeks to reach spermatogenesis suppression. Subjects were then randomized to either 7.5 or 10 mg/day for 40 weeks. In addition, 51 men were enrolled as a control group. In all, 81 subjects attained spermatogenesis suppression. Only one man discontinued treatment because of tiredness. Potassium levels fluctuated within the normal range. FSH increased consistently. Testicular volume decreased, but after discontinuation, values returned to levels not statistically different from admission. Of 19 subjects on the 7.5 mg/day dose group, 12 recovered sperm counts >20 million/mL within 12 months of discontinuing gossypol. In the 10 mg/day group, sperm counts recovered in only 10 of 24 subjects. Eight of the 43 patients remained azoospermic 1 year after stopping gossypol. All men diagnosed with varicocele failed to reverse spermatogenesis suppression. Gossypol blood levels indicated that sperm suppression occurs independently of concentration, whereas spermatogenesis recovery appears to be concentration-dependent. Gossypol may become a medical alternative to surgical vasectomy when the delay in onset of infertility is acceptable. When taken for 1 year, gossypol causes no reduction in sexual desire or frequency of intercourse. The possibility of reversal, occurring in 51% of the men on this regimen within 1 year after stopping gossypol, is an advantage of this compound as compared with surgical sterilization in many parts of the world.

[Nonsyndromic deafness and mitochondrial DNA mutation]

OBJECTIVE

To analysis whether there is any mtDNA 1555A-->G homoplasmic point mutation among familial nonsyndromic deafness.

METHOD

Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to screen the mutation 1555A-->G among four nonsyndromic deafness families.

RESULT

The same mutations were checked out in 4 of 5 individuals in 1 of 4 families.

CONCLUSION

The 1555A-->G change on mtDNA might be one of the multiple genetic defects and pathogenetic of familial nonsyndromic deafness.

Effects of tripchlorolide on the epididymides and testes of rats

AIM

To further evaluate the antifertility effects of tripchlorolide, a derivative of triptolide produced at the extraction procedure of Tripterygium wilfordii Hook. f., in male rats and to investigate its sites and possible mechanisms of action.

METHODS

In male rats, tripchlorolide was given by oral garage at a dose of 50 micrograms.kg-1.d-1 for 5 weeks, fertility was assessed by mating tests, and biochemical indices and light microscopic observation of the epididymides and testes were also performed.

RESULTS

Administration of tripchlorolide at 50 micrograms.kg-1.d-1 for 3 weeks did not influence the fertility of male rats, but 5-week treatment rendered the rats infertile. The density and motility of spermatozoa collected from cauda epididymides were reduced significantly. The epididymal weights, as well as the L-carnitine concentration and alpha-glucosidase content in the epididymal fluid were decreased. There were no significant differences in alpha-glucosidase and acid phosphatase (ACP) in caput epididymal homogenates between the control and the experimental rats. Obvious morphological changes were observed in the epididymal spermatozoa, mainly including head and tail separation or acrosome curving. Sloughed spermatids were found in the seminifeous and epididymal tubules. In testicular homogenates, tripchlorolide had no influence on the lactate dehydrogenase-C4 (LDH-C4) and hyaluronidase activities. No apparent lesions were observed in the seminiferous and epididymal epithelium.

CONCLUSION

At the dose level employed, tripchlorolide has a significant effect on the fertility in male rats and the primary sites of action may be spermatids and testicular and epididymal spermatozoa.

Effects of anordrin, droloxifene, nomegestrol, and mifepristone on cultured rat luteal cell apoptosis

AIM

To study the effect of four kinds of antifertility agents anordrin(Ano), droloxifene(Dro), nomegestrol (Nom), and mifepristone (Mif) on luteal cell apoptosis.

METHODS

Cultured rat luteal cells were incubated with different agents. HE stain was used to observe morphological changes. Extracted DNA was electrophoresed on agarose gel. Apoptotic cells were quantitated by flow cytometry.

RESULTS

All 4 drugs reduced cell viability. Dro induced apoptosis while the other 3 drugs induced necrosis. Typical DNA ladders were observed after cells were incubated with Dro and there were 15.4%, 75.4%, or 90.5% apoptotic cells after treatment with Dro 1.25, 2.5, or 3.75 mg.L-1, respectively.

CONCLUSION

Dro induced apoptosis while Ano, Nom, and Mif induced necrosis in cultured rat luteal cells.

[Effect of gossypol in combination with misoprostol on termination of early pregnancy in rats and mice]

Treatment of mice with misoprostol alone at doses ranging from 200 to 6400 micrograms.kg-1, qid on day 6-8 or bid on day 9 of gestation, the rate of effective early pregnancy interruption were low and showed no dose effect relation. When giving misoprostol 200-6400 micrograms.kg-1 bid on day 9 of gestation following administration of gossypol 50 mg.kg-1 qid on day 6-8, the rate of abortion increased as the dose of misoprostol increased, and the ED50 of misoprostol was 397.8 micrograms.kg-1. The ED50 of gossypol given orally on day 6-8 of gestation was 69.4 mg.kg-1. However, when gosyypol was given in combination with misoprostol 400, 800 or 1600 micrograms.kg-1 on day 9 bid, the ED50 of gossypol decreased to 63.2, 48.6 or 34.9 mg.kg-1, respectively. The results suggest that combination of gossypol and misoprostol showed synergistic effect on termination of early pregnancy in mice. Misoprostol obviously strengthened the uterine contraction of rats both in early pregnancy and estrus in vitro. The contraceptive intensity of contraction was increased as the dose of misoprostol increased from 10(-9), 10(-8) to 10(-7) mol.L-1, and the estrus group was higher than the early pregnancy group (P < 0.01). Gossypol(10(-5)-10(-6) mol.L-1) showed no effect on the uterine activity in rats, but the sensitivity of the uterus of the early pregnant rats to misoprosrol was found to be significantly increased by treatment with gossypol on day 6-8 of gestation (P < 0.01). Degeneration of the decidual was observed under light microscopy when gossypol 80 mg.kg-1.d-1, or misoprostol 800 micrograms.kg-1.d-1, or gossypol 40 mg.kg-1.d-1 combined with misoprostol 400 micrograms.kg-1.d-1 was given orally to rats on day 6-8 of pregnancy. The degeneration of cells was more remarkable when both drugs were given in combination. The assay of immunoreactivity for PR demonstrated that the distribution and content of PR in uterine decidua had no difference between the control group and the treated groups.

[Determation of strychnine and brucine in Strychnos by HPLC]

This paper describes the determination of strychnine and brucine in the seeds, root, stem and leaves of Strychnos species by HPLC. The analytical column used was ZY110 YNG-C18. The mobile phase was KH2PO4(0.01 mol.L-1)--MeOH(73:27), pH2.5, regulated by 10% H3PO4. Flow rate was 1.0 ml.min-1. The detection wavelength was 264 nm. The linear ranges of strychmine and brucine were 0.18-7.26 micrograms and 0.11-4.32 micrograms, respectively. The recoveries of strychnine and brucine were 98.27% and 98.04%, respectively. The analytical results showed that the contents of strychnine and brucine in samples showed great difference between different species. The contents of strychnine in the seeds of Strychnos wallichiana and S. ignatii were 5.6% and 3.9%, respectively. These results show that the two Strychnos species may be developed as the resources of strychnine.

[The effects of gossypol on rat luteal cells, human decidual cells and cytotrophoblasts]

The direct effects of gossypol on the serum-free primary cultures of rat luteal cells and cytotrophoblasts were observed. The results indicate that: (1) Gossypol affected the viability of the cultured rat luteal cells, LD50: 1.6 (0.4-2.9) micrograms.ml-1. (2) The basal secretions of progesterone were significantly inhibited at low and high concentrations. The activities of 3 beta-HSD, adenyl cyclase and hCG-stimulated progesterone production were inhibited by higher concentrations of gossypol. (3) Gossypol damaged cultured human decidual cells and cytotrophoblasts, the LD50 were 3.5(0.4-6.6) micrograms.ml-1 and 4.1(0.6-7.6) micrograms.ml-1, respectively. These results suggest that the luteolytic effect is the main mechanism of action for the termination of early pregnancy by gossypol, while the direct damaging effects on decidual cells and cytotrophoblasts may also play a role in the termination of early pregnancy.

Effect of DL111-IT on progesterone biosynthesis and viability of rat luteal cells in vitro

AIM

To study the influence of DL111-IT on progesterone biosynthesis of cultured luteal cells (LC).

METHODS

LC viability was assessed with trypan blue dye exclusion and progesterone concentration was measured with radioimmunoassay.

RESULTS

DL111-IT decreased the viability of LC after 24-h incubation, its ED50 being 7.7 (95% confidence limits: 7.1-8.5) mg.L-1. DL111-IT inhibited basal secretion of progesterone in a concentration-dependent manner, and 3 mg.L-1 decreased progesterone concentration by 25% vs control. DL111-IT 3 mg.L-1 also inhibited the stimulatory effect of forskolin (cAMP activator) 10 mumol.L-1 and pregnenolone [converted to progesterone by 3 beta-hydroxysteroid dehydrogenase-isomerase complex (3 beta-HSD)] 10 mumol.L-1 on progesterone production in cultured LC, and their inhibitory rates were 43% and 155%, respectively. At the same concentration, DL111-IT did not influence hCG-induced progesterone production.

CONCLUSION

DL111-IT inhibited progesterone synthesis by suppressing the conversion of pregnenolone to progesterone (inactivating 3 beta-HSD) and suppressed the activity of cAMP. DL111-IT 6-24 mg.L-1 decreased the viability of LC.

Results of a user satisfaction study carried out in women using Uniplant contraceptive implant

A study of the acceptability of Uniplant, a 12-month single implant of nomegestrol acetate, included 819 women from Africa, Latin America, and China, participating in a clinical trial of Uniplant. A standard, pre-coded questionnaire was specially designed for this purpose and applied at the moment of removal of implant, either at the end of 12 months of use or at the time of discontinuation for whatever reason. The level of satisfaction proved high when users' comparison with their previous contraceptive method, users' recommendation of Uniplant to others, users' intention to use the method in the future, and service satisfaction were taken into consideration. Uniplant was considered easy to use, safe (low risk of pregnancy), and also to cause fewer side effects than other methods. When asked about the least liked feature of Uniplant, almost half the respondents said that there was nothing that they disliked and about one-third mentioned the changes in their menstrual pattern. However, according to the clinical trial, over half of the Uniplant users have bleeding patterns similar to untreated cycles. The majority of respondents did not feel any discomfort during the procedure of insertion and removal of the implant. About 70% of patients in the study stated that they required contraception for more than one year and most of these women said that they did not mind having to change the implant every year.

Multicenter clinical trial on the efficacy and acceptability of a single contraceptive implant of nomegestrol acetate, Uniplant

Uniplant, a single Silastic implant containing nomegestrol acetate, provides contraceptive efficacy for one year. Uniplant use for one year was studied in 1,803 healthy women of reproductive age, enrolled from 10 centers in 9 countries, after informed consent. Implants were placed subdermally either in the upper arm or in the gluteal region. Two-hundred-seventy-six subjects discontinued prior to completing one year of study. Cumulative discontinuation rate at 12 months was 15.72%. Medical reasons for discontinuation were principally menstrual-related. Fifteen pregnancies occurred during the one year study period, resulting in a 12-month net cumulative pregnancy rate of 0.94%. Approximately 56% of subjects using Uniplant had bleeding patterns similar to normal menstruation. Results from this study confirm that Uniplant is an efficient, well tolerated, 12-month contraceptive implant, with the advantage of easier insertion and removal of the single implant compared to other multiple implant methods.

Comparative study on intermittent versus continuous use of a contraceptive pill administered by vaginal route

A multicenter, international, randomized, comparative trial was conducted to assess the acceptability, efficacy and safety of two different schedules of a contraceptive pill, containing 250 micrograms levonorgestrel and 50 micrograms ethinyl estradiol, administered by the vaginal route. One schedule of daily administration for 21 days with a seven-day interruption to allow withdrawal bleeding was compared to daily administration without interruption for bleeding. A total of 900 women were recruited in three countries, Brazil, Egypt and China; 7,090 women-months of vaginal pill use were recorded (3,364 using the pills intermittently and 3,726 continuously). Four undesired pregnancies occurred, one in Egypt and three in China, all four in women using the pills intermittently. There was a statistically significant difference (p = 0.486) in pregnancy rate between the two groups. There were no other significant differences in discontinuation rates despite marked differences in bleeding patterns, amenorrhea predominating in the continuous use group. Hemoglobin levels increased significantly in the two groups but hematocrit was significantly higher in the continuous use group.

Effects of repeated cocaine injections on cochlear function

The effects of repeated cocaine administration on cochlear function were evaluated by measuring amplitude-intensity and latency-intensity functions of the whole-nerve action potential of the auditory nerve. Whole-nerve action potential input/output functions obtained using tone-pips of 0.5, 1, 2, 4 and 8 kHz in a group of cocaine-treated subjects were compared with those obtained in saline-treated animals. All measurements were made 24 h after the last treatment. Amplitudes of whole-nerve action potentials were enhanced in the cocaine-treated animals compared to the control group. No statistically significant differences in latency-intensity functions were seen after cocaine treatment. The effect of chronic cocaine exposure also was examined on catecholamine innervation in the cochlea using immunohistochemical techniques. The density of adrenergic innervation was reduced in the cocaine-treated animals.

[The effects of injection salviae miltiorrhizae in preventing and treating fat embolism syndrome]

This study was to examine the effects and mechanisms of injectio salviae miltiorrhizae (ISM) in preventing and treating fat embolism syndrome (FES), which was simulated by intravenous injection of homologous bone marrow fat in 16 dogs. PaO2, free fatty acids (FFAs), TXA2/PGI2, SOD/MDA were measured in different times combined with X-ray, conjunctiva microcirculation observation, radioisotope scanning and histologic examination. It was found that in the control group there were a significant fall in PaO alpha and rise in FFAs and MDA; blood clot stained with oil red O showed many fat droplets; radioisotope scanning revealed mild hypoperfusion or perfusion defects. In the treatment group, arterial oxygen levels were maintained, serum level of FFAS and MDA was reduced significantly. It is concluded that there is damage induced by oxygen-derived radicals in FES, LSM is an effective therapy for the FES, and 99mTc radioisotope scanning is a promising technique for noninvasive identification of FES in the early stage.

Comparative study on the efficacy, acceptability, and side effects of a contraceptive pill administered by the oral and the vaginal route: an international multicenter clinical trial

The objective of this multicenter randomized clinical trial was to compare the efficacy, acceptability, and occurrence of side effects associated with the oral versus vaginal route of administration of contraceptive pills. Eight hundred nineteen healthy, parous women of reproductive age were recruited at family planning clinics and research centers, members of the South to South Cooperation in Reproductive Health, in seven countries of the developing world. These women were randomly assigned to use either oral or vaginal administration of the same contraceptive pill, which contained 250 micrograms levonorgestrel and 50 micrograms ethinyl estradiol. No statistically significant differences were found in discontinuation rates between the two groups after 1 year. Involuntary pregnancy rates after 1 year were not statistically significantly different between the two groups. The vaginal route of administration appears to be as acceptable and efficacious as the oral route.

Acute effects of cocaine on cochlear function

The effects of a single administration of cocaine on the cochlea was evaluated by measuring amplitude-intensity functions of the N1 response of the auditory nerve. Amplitude-intensity functions of the N1 response to tone-pips of 500 Hz, 1, 2, 4 and 8 kHz were obtained before and after intraperitoneal injection of either saline, 3 mg/kg or 25 mg/kg of cocaine. N1 amplitudes were decreased after the administration of cocaine and this reduction was found to be dose dependent. The influence of cocaine on cochlear blood flow (CBF) was examined in order to test the possibility that cocaine induced reductions in CBF underlie these electro-physiological changes. Corresponding decreases in cochlear blood flow after cocaine exposure were observed.

Differences in serum potassium concentrations in normal men in different geographic locations

Hypokalemia has been associated with the taking of gossypol, a potential oral antifertility drug for men. Because the frequency of this response differed in different parts of the world, this study was done to learn if "normal" serum [K+] also differed. [K+] was measured by flame photometry in serum from apparently normal men from Austria (n = 30), China (53), Brazil (100), the Dominican Republic (38), and the US (103), and in plasma from Nigerian men (82). The mean (SD) for [K+] in Chinese men, 3.82 (0.27) mmol/L, was lower than that in Brazilians [4.06 (0.29) mmol/L], Austrians [4.14 (0.44) mmol/L], Dominicans [4.37 (0.33) mmol/L], or Americans [4.38 (0.37) mmol/L]. Apparently there are regional differences in average serum [K+], with men in China having lower serum [K+] than men elsewhere. This may predispose them to hypokalemia.

Differences in serum potassium concentrations in normal men in different geographic locations

Hypokalemia has been associated with the taking of gossypol, a potential oral antifertility drug for men. Because the frequency of this response differed in different parts of the world, this study was done to learn if "normal" serum [K+] also differed. [K+] was measured by flame photometry in serum from apparently normal men from Austria (n = 30), China (53), Brazil (100), the Dominican Republic (38), and the US (103), and in plasma from Nigerian men (82). The mean (SD) for [K+] in Chinese men, 3.82 (0.27) mmol/L, was lower than that in Brazilians [4.06 (0.29) mmol/L], Austrians [4.14 (0.44) mmol/L], Dominicans [4.37 (0.33) mmol/L], or Americans [4.38 (0.37) mmol/L]. Apparently there are regional differences in average serum [K+], with men in China having lower serum [K+] than men elsewhere. This may predispose them to hypokalemia.

Effects of multiglycosides of Tripterygium wilfordii (GTW) on rat fertility and Leydig and Sertoli cells

Primary cultures of rat Leydig and Sertoli cells were used to evaluate the direct effects of GTW on testicular cells and to compare these to the effects of gossypol acetate. Both GTW and gossypol acetate can affect the survival of Leydig and Sertoli cells. But Sertoli cells are much more sensitive than Leydig cells, either to gossypol acetate or GTW. Leydig and Sertoli cells all died when they were exposed to gossypol acetate or GTW at a dose of 3.0 micrograms/ml or 30 micrograms/ml, respectively, for 24 hours. The cell survival-time course demonstrated that the cell numbers were decreased after 2 hours, and especially so after 8 hours. No significant changes were observed in testosterone production in Leydig cells after 24 hours of exposure to 1.0-20 micrograms/ml GTW. The forward motility of epididymal spermatozoa was completely lost and fertility of rat was significantly inhibited after the treatment of GTW in vivo. It is concluded that GTW does affect the fertility of rat and viability of cultured rat Leydig and Sertoli cells.

[Effects of pseudolaric acid B on blood flows of endometrium and myometrium in pregnant rats]

Effects of pseudolaric acid B (PB) on endo- and myo-metrial blood flows were measured by hydrogen gas clearance technique in 336 pentobarbital-anesthetized rats divided into control and 2 medicated groups (ig PB 20 and 30 mg.kg-1 on d 7-9 of pregnancy). Measurements of endo- and myo-metrial blood flows were done on d 7-14 of pregnancy. Results showed that the endo- and myo-metrial blood flows were reduced by 33-66% and 30-65% respectively, vs ig 1% CMC 0.5 ml (P less than 0.01). Uterine weight during d 10-14 of pregnancy stopped gain. The systemic arterial pressure remained relatively unchanged. It is concluded that PB causes a significant decrease of blood flow in both endo- and myometrium, which is accounted as the most important cause of embryo's death.

[Endocrine activity of pseudolaric acids A and B and their effects on sex hormones, prostaglandins, uteri, and fetuses]

Two novel diterpendoids, pseudolaric acids A and B (PA, PB) first isolated from the root of Pseudolarix kaempferi Gorden in China, have been reported to possess significant antifertile activities in rats, hamsters, rabbits, and dogs. The present study demonstrated that neither PA nor PB had estrogenic and antiestrogenic activities, they also did not inhibit deciduous formation. When an effective dose of PB 30 mg.kg-1 was given on d 6 of pregnancy and the hormonal determinations were done on d 8 and d 12 of pregnancy, the progesterone, estradiol and prostaglandins E, F levels in plasma and the uterine prostaglandin E, F levels were not significantly reduced vs those of the control rats. The human uterus was used as the experimental material in vitro. PA and PB 200 micrograms.ml-1 cultural medium (McCoy's 5a medium) damaged only a part of the decidual and trophoblast cells. In partially depolarized isolated uterine smooth muscles of early pregnant rats, PA and PB caused a decline in the contractile tension. A low dose of PB 2 mg.kg-1.d-1 was given ig on d 6-12 of pregnancy in rats caused the body weight and the length of fetuses and the placental weight value significantly lower than those of the control. Thus, ischemia due to the vasoconstrictor effect is probably of great, and sometimes of supreme, importance.

Relationship between hormone profiles and the restoration of spermatogenesis in men treated with gossypol

Gossypol acetic acid was administered orally to 35 male volunteers at a dose of 20 mg once a day for 52-70 days in the loading phase and twice a week for 22 months in the maintenance phase. Sperm counts and the serum concentrations of LH, FSH, prolactin, testosterone and oestradiol were monitored regularly during treatment and for a follow-up period of 12 months. At around 90 days after treatment, all treated participants approached or attained azoospermia and remained at this level throughout the maintenance phase. By the end of the follow-up phase, eight treated men were still azoospermic, while sperm counts in the other 27 men were restored to normal levels. The only hormone that changed significantly during and after the treatment was FSH. From the 6th month of the treatment to the end of the follow-up phase, serum concentrations of FSH in the eight participants that reached irreversible azoospermia were significantly higher than in the other 27 men or in controls. It is suggested that monitoring of FSH levels might be of diagnostic use for identifying those participants with irreversible azoospermia during gossypol treatment.

Observation on Corti's organ of entire cochlea in the guinea pig by scanning electron microscopy

The entire organ of Corti on guinea pigs were observed by SEM, which has a high resolving power and can be used for a three dimensional study on the fine structure of the cochlea. After the animals were sacrificed, primary perfusion with 3% glutaraldehyde through the oval and round windows was completed in 5 minutes and with 1% OsO4 for the next fixation. After microdissection, the entire organ of Corti was exposed and remained on the modiolus. The OTO technique and critical point drying were used to prepare SEM specimens. The organ of Corti of guinea pig was found to be very similar to that of human being. The basilar membrane widened from the base to the apex of the cochlea. The sensory hair cells, inner and outer, had different appearances marked by shallow U-shaped IHC and W-shaped OHC cilia. The longest layer of OHC cilia left imprints on the undersurface of the tectorial membrane. The relationship between the hair cells and supporting were cells shown. We conclude that the whole specimen of the organ of Corti is more advantageous than piece specimens in acoustic physiological and pathological research by integrated anatomical pattern.

Structure-activity relationships of pyrimidine nucleosides as antiviral agents for human immunodeficiency virus type 1 in peripheral blood mononuclear cells

The structure-activity relationships of several pyrimidine nucleosides related to 3'-azido-3'-deoxythymidine (AZT) were determined in human immunodeficiency virus type 1 (HIV-1) infected human peripheral blood mononuclear cells. These studies indicated that nucleosides with a 3'-azido group on the sugar ring exhibited the most potent antiviral activity. Substitution at C-5 with H, CH3, and C2H5 produced derivatives with the highest potency, whereas alkyl functions greater than C2, including bromovinyl substitution reduced the antiviral potency significantly. Changing the 3'-azido function to an amino or iodo group reduced the antiviral activity. Replacement of the uracil ring by cytosine or 5-methylcytosine produced analogues with high potency and low toxicity. Modification of the 5'-hydroxy group markedly reduced the antiviral activity. Similarly, various C-nucleoside analogues related to AZT and 2',3'-dideoxycytidine were inactive and nontoxic. From these systematic studies 3'-azido-2',3'-dideoxyuridine (5a), 3'-azido-5-ethyl-2',3'-dideoxyuridine (5c), and 3'-azido-2',3'-dideoxycytidine (7a) and its 5-methyl analogue (7b) were identified as potent and selective anti-HIV-1 agent in primary human lymphocytes.

4-bromo-7-hydroxyindan oxime--a new potent spermicidal agent

The spermicidal effect of eleven chelating agents with a ring structure was evaluated using human spermatozoa. All were potent spermicides in vitro. 4-Bromo-7-hydroxyindan oxime (S-11) was the most potent and its lowest effective concentration for immobilizing sperm within 20 sec was 0.02 mg/ml; its toxicity was also the lowest of the compounds tested with an acute LD50 of 2936 mg/kg. In rabbits, S-11 caused no local irritation to the conjunctiva or quadriceps femoris muscle at a concentration of 0.02 mg/ml. Heart, liver, kidney, spleen, lung and vagina showed no pathological changes when vaginal pessaries containing 1 or 10 mg of S-11 were administered daily, six times a week for 90 days. When vaginal pessaries of 8 or 40 mg S-11 were administered on days 7-15 after mating, no significant abnormality in general appearance, in the viscera or bone development of foetuses were found.