Cutaneous injury and Vibrio vulnificus infection.
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Adult↗
Biomedical subjects
P H Chung
Publications and source records attributed to P H Chung.
Consumption of viscera as the most important risk factor in the largest outbreak of shellfish poisoning in Hong Kong, 2005.
Poisoning from shellfish toxins is associated with significant morbidity worldwide. During 10-15 March 2005, 36 clusters of shellfish poisoning related to consumption of fresh scallops (Atrina vexillum) were reported to the Center for Health Protection, Department of Health Hong Kong. We conducted a case-control study to identify the risk factors associated with shellfish poisoning. Detailed demographic, clinical, shellfish consumption data of these subjects were collected using standardized questionnaires. Fifty-eight cases and 44 controls were identified. The mean age for the cases was 37.5 years (range 10-81 years); 45% (n=26) were male. Ninety-five percent had onset of symptoms within 12 hours of consumption of scallops (range: 10 minutes to 30 hours, median: 45 minutes). Dizziness (87.9%) and blurred vision (53.4%) were the predominant symptoms. The mean number of pieces of scallop meat and viscera taken by the cases were 3.7 and 3.6, respectively, significantly higher than that for the controls, which were 1.6 (p<0.001) and 0.5 (p<0.001), respectively. Forty-two percent (n=22) and 19% (n=7) of cases and controls, respectively, took soup/sauce from the same dish that was cooked with the scallops (p=0.02). Consumption of scallop viscera was identified as the only significant risk factor (Adjusted OR=9.93, p=0.001) after adjusting for other risk factors. The result show that consumption of scallop viscera is an important risk factor for shellfish poisoning. The public should be warned specifically in health education messages to avoid eating viscera of scallops.
Adolescent↗
HIV-1 genotypic zidovudine drug resistance and the risk of maternal--infant transmission in the women and infants transmission study. The Women and Infants Transmission Study Group.
OBJECTIVES: Although the treatment of pregnant women and their infants with zidovudine (ZDV) has been remarkably effective in preventing the perinatal transmission of human HIV-1, many potentially preventable infections still occur. To examine whether the risk of perinatal infection is increased among women who carry ZDV-resistant HIV-1, the role of genotypic ZDV resistance in perinatal transmission was evaluated. METHODS: The reverse transcriptase (RT) region of clinical isolates from culture supernatants of 142 HIV-1-infected women enrolled in the Women and Infants Transmission Study (WITS), who had been treated with ZDV during pregnancy was sequenced. Results from genotypic sequencing were linked to demographic, laboratory, and obstetrical databases, and the magnitude of association of having consensus drug-resistant HIV-1 RT mutations with transmission was estimated. RESULTS: Twenty-five per cent (34/142) of maternal isolates had at least one ZDV-associated resistance mutation. A lower CD4 cell percentage and count (P= 0.0001) and higher plasma HIV-1 RNA (P=0.006) were associated with having any ZDV resistance mutation at delivery. Having any RT resistance mutation [odds ratio (OR): 5.16; 95% confidence interval (CI): 1.40, 18.97; P=0 0.01], duration of ruptured membranes [OR: 1.13 (1.02, 1.26) per 4 h duration; P= 0.02], and total lymphocyte count [OR: 1.06 (1.01, 1.10) per 50 cells higher level; P=0.009] were independently associated with transmission in multivariate analysis. CONCLUSION: Maternal ZDV resistant virus was predictive of transmission, independent of viral load, in these mothers with moderately advanced HIV-1 disease, many of whom had been treated with ZDV before pregnancy.
Anti-HIV Agents↗
Reconstruction of human hard-palate mucosal epithelium on de-epidermized dermis.
Artificial hard-palate mucosa equivalents were reconstructed using keratinocytes derived from normal human hard-palate and de-epidermized dermis. Reconstructed hard-palate mucosal epithelium formed in three-dimensional culture was compared to native hard-palate mucosal epithelium and reconstructed oral buccal mucosal epithelium with regard to keratin expression. Artificial hard-palate mucosal epithelium reconstructed in medium with delipidized serum showed a differentiation pattern similar to that of hard-palate epithelium in vivo. The present study also confirmed that keratinocytes derived from hard-palate mucosa are intrinsically different from those of nonkeratinizing oral surfaces.
Cell Communication↗
An analysis of the effect of age on implantation rates.
PURPOSE: To evaluate implantation rate as a function of age. METHODS: A total of 1621 consecutive cycles of IVF were evaluated for implantation as a function of age at The New York Hospital/Cornell Medical Center. RESULTS: An overall implantation rate of 23.3% (1328/5691) was found. The implantation rate as a function of age decreased in a nonlinear fashion. Implantation remained constant until the age of 35 and then decreased in a significantly, linear fashion by 2.77% per year (P < 0.001, R2 = 0.975). A formula to predict implantation rates for a given age was developed: Implantation rate = -119.352 + (9.985 x Age - (0.164 x Age2)). CONCLUSIONS: We have demonstrated that implantation rates remain constant until the age of 35 at which time a linear decrease of 2.77% per year is observed.
Adult↗
Selective vertical transmission of HIV-1 antiretroviral resistance mutations.
OBJECTIVE: To examine the patterns of vertical transmission of zidovudine (ZDV) resistance mutations. DESIGN: HIV-1 reverse transcriptase codons 10-250 were sequenced from 24 pairs of ZDV-exposed women and their HIV-infected infants as part of the Women and Infants Transmission Study. METHODS: Viral RNA was extracted from tissue culture supernatants and sequenced using fluorescent dye-primer chemistry and an automated sequencer. RESULTS: For 17 of these pairs, maternal and infant sequences were identical to one another and lacking known ZDV resistance mutations. The remaining seven maternal sequences contained known mutations associated with ZDV resistance at reverse transcriptase codons 70, 210, 215 and 219. In each case where the maternal HIV isolate showed a pure mutant species, the infant sequence was identical. When the maternal sequence showed the presence of a sequence mixture at codon 70 or 219, the infant's virus showed only wild-type sequence even when the ZDV-resistant mutant was quantitatively dominant in the mother. The single maternal HIV isolate showing mixed sequence at codon positions 210 and 215 transmitted an unmixed mutant to the infant at both positions. When maternal mixtures were present at sites not associated with ZDV resistance, only the dominant species appeared in the infant. CONCLUSIONS: When maternal HIV isolates contained mixed wild-type and ZDV-resistant subpopulations, only a single component of the mixture could be detected in the infected infants. Resistance mutants without the codon 215 mutation were not transmitted from mixtures, even when the mutants formed the majority of circulating maternal virus. In perinatal HIV transmission, specific ZDV-resistant HIV genotypes circulating in the maternal virus pool may influence whether infection in the infant will be established by a wild-type or ZDV-resistant HIV strain.
Anti-HIV Agents↗
The use of intracytoplasmic sperm injection with electroejaculates from anejaculatory men.
Electroejaculation has been successfully used for sperm procurement in anejaculatory men desiring fertility. However, electroejaculates typically have normal sperm numbers but poor motility, morphology, and functional deficiencies. Here we report the pregnancy outcome of a series of couples undergoing combined electroejaculation and in-vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). In all, 13 couples underwent a total of 18 cycles. The aetiologies of anejaculation included history of retroperitoneal lymph node dissection for testicular cancers, spinal cord injury and psychogenic causes. ICSI was performed on 192 oocytes, resulting in a fertilization rate of 75.5%. A total of 15 embryo transfers were performed using a total of 51 embryos. Clinical pregnancy rate, as defined by positive fetal heart rate(s) using vaginal sonography, was 55.6% per retrieval; implantation rate was 33.3% per embryo. These rates appear to be similar to those obtained in standard IVF for non-male factor infertility, or ICSI for male factor infertility. The use of ICSI for electroejaculates undoubtedly provides these couples with the highest chance of pregnancy.
Ejaculation↗
Hormone and prostaglandin F2 alpha regulation of messenger ribonucleic acid encoding steroidogenic acute regulatory protein in human corpora lutea.
Steroidogenic acute regulatory (StAR) protein mediates the rapid increase in steroid hormone biosynthesis in response to tropic hormones by facilitating transport of cholesterol into the inner mitochondrial membrane. Although our laboratory has recently reported on the hormonal regulation of StAR mRNA in the rat ovary, the same regulation in the human corpus luteum requires analysis. To this end, a human StAR complementary DNA (cDNA) probe of 858 bp was generated using reverse transcriptase-PCR and RNA from human corpora lutea. The StAR sequence was confirmed by dideoxy chain-termination sequence analysis. Northern blot analysis using the StAR cDNA probe on human corpora lutea mRNA showed that the probe hybridized to a major 1.6-kb transcript and a minor 4.4-kb transcript. Examination of corpora lutea of different luteal phases revealed that the basal expression of the 1.6-kb transcript was significantly more abundant in the early (days 15-19) luteal phase than in the middle (days 20-23) or late (days 24-28) phases. To examine the hormonal regulation of StAR mRNA, corpora lutea were treated in vitro with increasing concentrations of human chorionic gonadotropin (hCG) or prostaglandin F2 alpha (PGF2 alpha). Following hCG stimulation, both 1.6- and 4.4-kb StAR transcripts were increased. A statistically significant increase of 2.2- and 1.8-fold in the 1.6-kb transcript was seen with hCG concentrations of 50 and 100 mIU/mL, respectively. This increase was coupled with a significant elevation in media progesterone levels. In contrast, PGF2 alpha treatment significantly decreased both StAR messenger ribonucleic acid (mRNA) expression and media progesterone levels at concentrations of 500 and 5000 ng/mL. This investigation demonstrated that StAR mRNA is regulated by tropic hormones and prostaglandins in the human corpus luteum. The parallel change in StAR mRNA in conjunction with a change in progesterone levels further supports StAR's putative role in the regulation of steroidogenesis.
Adult↗
Gamete intrafallopian transfer. Comparison of epidural vs. general anesthesia.
OBJECTIVE: To investigate the reproductive outcome of laparoscopic gamete intrafallopian transfer (GIFT) performed under epidural vs. general anesthesia. STUDY DESIGN: Retrospective analysis of 110 consecutive laparoscopic GIFT procedures performed under general or epidural anesthesia. All patients underwent controlled ovarian hyperstimulation employing human menopausal gonadotropin and gonadotropin releasing hormone agonist, given either in the midluteal or early follicular phase. Data were retrieved concerning age, diagnosis, estradiol levels and maximum follicular diameter at the time of human chorionic gonadotropin injection, percentage of mature oocytes retrieved and number of oocytes transferred. These variables were compared using the independent means t test. Pregnancy rates and outcome between the general and epidural anesthesia groups were compared with the chi 2 test. RESULTS: Of the 110 procedures, 84 were performed under general anesthesia, whereas 22 were done using epidural anesthesia. Four procedures started with epidural anesthesia and were converted to general anesthesia because of upper abdominal discomfort. The success rate of epidural anesthesia, therefore, was 85% (22/26). There were no significant differences in the confounding variables between the general and epidural anesthesia groups. However, patients receiving epidural anesthesia had a significantly higher pregnancy rate, 59.1%, and a live birth rate of 40.9% as compared to 31.0% and 21.4%, respectively, for the general anesthesia group. CONCLUSION: Laparoscopic GIFT can be performed safely under epidural anesthesia. Because of the higher pregnancy and live birth rates, epidural is the anesthetic of choice for GIFT. However, a prospective, randomized study is needed to confirm the above observation.
Adult↗
The expression of the low affinity nerve growth factor receptor in long-term denervated Schwann cells.
Schwann cells in the distal stump of injured peripheral nerves synthesize the low affinity nerve growth factor receptor (p75). In this study we used short-term (1 week) and long-term (1-12 months) transected distal sciatic nerves of rats to determine the variations of p75 expression by using immunocytochemistry and in situ hybridization. Semi-quantitative analysis revealed that the synthesis of the protein product of the p75 gene is rapidly enhanced to reach a peak within the 1 month after denervation. After that it gradually decreased and was barely detectable 6 months following denervation. Double immunocytochemistry for p75 and the S100 protein revealed that p75 immunoreactivity is confined to the Schwann cells. Quantitative analysis of our in situ hybridization experiments revealed that the upregulation of the p75 mRNA parallels the enhanced synthesis of the corresponding protein and reaches a peak within 1 month, which is maintained until the second month after the transection and declines thereafter to reach background levels at 4 months. The electron microscopic observations reveal that the increase in the number of nuclei in the distal stump belong to severely atrophied Schwann cells and fibroblasts. Since the presence of p75 in the Schwann cells is necessary for reinnervation, our results indicate that, based on the expression of p75, the Schwann cells will provide a most suitable environment for the regenerating axons up to the first month. At later stages the ability of the Schwann cells to synthesize p75 and cell adhesion proteins such as N-CAM and GAP 43 decreases which may be one of the factors that contribute to poor functional recovery if the regenerating axons reach the distal stump after long periods of time.
Animals↗
Correlation between semen parameters of electroejaculates and achieving pregnancy by intrauterine insemination.
OBJECTIVE: To investigate whether any parameter in the routine semen analysis of electroejaculates is correlated with success in achieving pregnancy by IUI. DESIGN: Retrospective observational study. SETTING: An Assisted Reproductive Program at a tertiary care university center. PATIENT(S): Twenty-seven anejaculatory men with spinal cord injury (n = 24) or history of retroperitoneal lymph node dissection (n = 3), thirteen of whom attempted conception with their wives. INTERVENTION(S): Anejaculatory men underwent rectal probe electroejaculation and electroejaculates were used for IUI. MAIN OUTCOME MEASURE(S): Statistical correlation of semen parameters between electroejaculates that resulted in pregnancy and those that did not. RESULT(S): Seven pregnancies resulted from 56 IUIs using electroejaculates (pregnancy rate = 12.5% per IUI). The total motile sperm count and percentage of normal morphology were significantly higher in the specimens that resulted in pregnancies than those that did not. However, there was no statistically significant difference observed in pH, sperm concentration, or percentage of motility between the two groups. Swim-up techniques used to process electroejaculates significantly improved the motility of the specimens. No pregnancy occurred beyond the fifth IUI attempt. Repeated electroejaculation and duration of spinal cord injury had no effect on the quality of the ejaculates. CONCLUSION(S): The total motile sperm count and the percentage normal morphology of electroejaculates correlate with success in achieving pregnancy by IUI. Because repeated electroejaculation does not improve quality of ejaculate, the initial semen analysis of electroejaculates is not only useful in counseling couples undergoing such treatment program but should be planned for use as an inseminate.
Adult↗
Gamete intrafallopian transfer. Does smoking play a role?
OBJECTIVE: To investigate the effects of active and passive cigarette smoking on the outcome of gamete intrafallopian transfer (GIFT). STUDY DESIGN: A retrospective analysis of 98 patients who had laparoscopic GIFT was performed. Data were retrieved concerning age, diagnosis, amount of human menopausal gonadotropins (hMG) used for controlled ovarian hyperstimulation (COH), and number of oocytes retrieved and transferred. A detailed smoking history, if any, of patients and household members was obtained from chart review and an additional telephone survey. Pregnancy rates and outcome in active and passive smokers were compared to those of non-smokers. RESULTS: No difference was observed among active smokers (n = 19), passive smokers (n = 13) or nonsmokers (n = 66) regarding diagnosis, age percentage of mature oocytes retrieved or number of oocytes transferred during GIFT. However, active, but nor passive, smokers consumed a higher amount of hMG for COH as compared to nonsmokers. More important, pregnancy and live birth rates for active smokers (15.8% and 10.5%, respectively) were significantly lower than those for passive smokers (46.2% and 23.1%) and nonsmokers (45.5% and 33.3%). No difference, however, was noted between the latter two groups. CONCLUSION: Our results show that active, but not passive, smoking has a negative impact on GIFT pregnancy rates and outcomes. It is important to counsel patients against cigarette smoking prior to GIFT, but whether smoking cessation will improve the outcome needs further study.
Adult↗
Recurrent miscarriage: causes and management.
The workup is a challenge, as genetic, anatomic, endocrine, or immunologic factors may be involved. Although 60% of patients will have a successful pregnancy even without intervention, correctable causes should be sought.
Abortion, Habitual↗
Electroejaculation and assisted reproductive techniques for anejaculatory infertility.
OBJECTIVE: To report our experience with electroejaculation combined with intrauterine inseminations (IUI) and other assisted reproductive technologies. METHODS: Anejaculatory men desirous of fertility were evaluated in our Assisted Reproductive Program. Between March 1991 and December 1994, 26 men (age 24-48) underwent a total of 84 electroejaculations. Causes of anejaculation included spinal cord injury (n = 23) and retroperitoneal lymph node dissection (n = 3). Female partners were super-ovulated to improve the pregnancy rate. The success in sperm retrieval and pregnancy rates were determined, and the quality of electroejaculates was evaluated. RESULTS: Seventy-seven of 84 (92%) electroejaculations were successful, defined by retrieval of more than 10 x 10(6) total and more than 10(6) motile spermatozoa. Mean sperm count was 65 million/mL (range 0-569), but mean motility was only 16% (range 0-66). Mean normal morphology was 27% (range 0-71). Ten couples attempted conception. Fifty cycles of IUIs were performed, resulting in four normal term infants and one spontaneous abortion (pregnancy rate 10% per IUI). One patient failed to conceive with eight cycles of IUIs but became pregnant with in vitro fertilization-embryo transfer with micromanipulation using electroejaculates; she delivered a set of healthy twins. Two couples elected donor sperm insemination after failing to conceive by IUI with electroejaculates; both became pregnant. CONCLUSION: Electroejaculation offers an encouraging pregnancy opportunity for anejaculatory men who otherwise are considered infertile. Marked asthenospermia is observed in electroejaculates, the etiology of which remains obscure. Further studies to elucidate the cause may improve pregnancy rates.
Adult↗
Determination of HIV-1 susceptibility to reverse transcriptase (RT) inhibitors by a quantitative cell-free RT assay.
BACKGROUND: Mutations in the human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) gene confer resistance to antiviral drugs acting on RT. Current methods employed to detect such resistance require time-consuming culture techniques during which selective pressures may affect the outcome of the test. OBJECTIVES: We sought to determine whether drug-susceptible and drug-resistant HIV-1 derived from clinical specimens could be distinguished by the effects of the active form of the drug on the enzyme activity in a quantitative, cell-free RT assay. STUDY DESIGN: Polyethylene glycol (PEG)-precipitated virus was obtained from 7-day culture supernatants. RT activity in the lysed viral extracts was measured in the presence of increasing concentrations of the active form of the drug being tested. IC50 (50% inhibitory concentration) values were determined by application of the median effect equation. RESULTS: Assays from nine post-nevirapine therapy isolates gave IC50 values at least 2 logs greater than pre-nevirapine isolates. The method also correctly distinguished between isolates sensitive and resistant to 2',3'-dideoxyinosine (ddI), but not between the ZDV-sensitive and ZDV-resistant isolates tested. The results agreed with data obtained by sequencing and by culture-based susceptibility assays.
Cell-Free System↗
Human corpus luteum function in normal and abnormal pregnancy states.
Investigators have shed new light on the precise manner by which human chorionic gonadotropin rescues and regulates corpus luteum function in normal and abnormal pregnancy states. It has also been shown using ultrasound that both an undetectable or shrinking corpus luteum volume are predictive of poor pregnancy outcomes. Ultrasound and transvaginal color Doppler sonographic findings do not, however, correlate with either progesterone or 17-hydroxyprogesterone serum levels and, therefore, these imaging modalities alone are not reflective of corpus luteum function in early pregnancy.
Corpus Luteum↗
Assisted fertility using electroejaculation in men with spinal cord injury--a review of literature.
OBJECTIVE: To review the effectiveness of rectal probe electroejaculation in terms of pregnancy in treatment of anejaculatory males due to spinal cord injury. The characteristics of electroejaculates also are examined. DATA IDENTIFICATION: All English language studies reporting pregnancies as a result of electroejaculation from men with spinal cord injury and related publications on electroejaculation were identified through MEDLINE search and manual scanning of recent relevant journals. RESULTS: Electroejaculation has become an accepted mode of semen procurement in anejaculatory individuals, with a success rate of approximately 60% to 90% varying among different centers. In general these electroejaculates exhibit high sperm counts but low motility and poor sperm function. Retrograde ejaculation is also common. Pregnancies using electroejaculates have been documented since 1975 in the form of case reports and small series. Assisted reproductive technology recently has been used in conjunction with electroejaculation. Although results are encouraging, pregnancy rates, however, cannot be accurately estimated because of the lack of large series in the literature. CONCLUSIONS: An increasing number of spinal cord-injured patients desiring fertility can achieve pregnancy through combined use of electroejaculation and assisted reproductive techniques. Larger series are needed to establish an accurate pregnancy rate. Elucidation by further studies on etiology of sperm dysfunction of these individuals may improve their prognosis.
Ejaculation↗
Acute maternal obstructive renal failure in a twin gestation despite normal physiological pregnancy-induced urinary tract dilation.
Obstructive renal failure due to an overdistended uterus is a very rare complication of pregnancy. Most previously reported cases have involved twin gestations, the majority occurring in the presence of polyhydramnios. We describe a patient with a twin gestation who developed acute obstructive renal failure despite only very mild physiological pregnancy-induced dilation of the urinary collecting system in the absence of polyhydramnios. This case suggests that acute obstructive uropathy should be considered as a rare cause of acute renal failure even in cases with seemingly normal pregnancy-induced physiological urinary tract dilation.
Acute Kidney Injury↗