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Biomedical subjects

P A Richardson

Publications and source records attributed to P A Richardson.

18 recordsLinked to original sources
PubMed2004

Rapid identification of Phytophthora ramorum using PCR-SSCP analysis of ribosomal DNA ITS-1.

AIMS: The primary objectives of this study were to determine if a single-strand conformation polymorphism (SSCP) analysis can be used for rapid identification of Phytophthora ramorum, an important quarantine plant pathogen worldwide, and to further assess the potential of the SSCP technique as a taxonomic tool for the genus Phytophthora. METHODS AND RESULTS: SSCP of ribosomal DNA internal transcribed spacer 1 was characterized for 12 isolates of P. ramorum, using a recently reported protocol. The SSCP patterns of this species then were compared with those of 18 closely related Phytophthora species. Phytophthora ramorum had a unique pattern and was easily distinguished from genetically, morphologically and ecologically close relatives. CONCLUSION: An immediate benefit of this study is provision of a highly effective and efficient identification tool for P. ramorum in the quarantine process. SIGNIFICANCE AND IMPACT OF THE STUDY: This study also provides additional evidence demonstrating that the SSCP is an ideal DNA marker for species differentiation within the genus Phytophthora.

DNA, Ribosomal Spacer↗
PubMed2001

The role of diabetes in hepatocellular carcinoma: a case-control study among United States Veterans.

OBJECTIVE: Diabetes mellitus (DM) has been reported to increase the risk of hepatocellular carcinoma (HCC). We carried out a case-control study to examine the role of DM while controlling for several known risk factors of HCC. METHODS: All hospitalized patients with primary liver cancer (PLC) during 1997-1999 were identified in the computerized database of the Department of Veterans Affairs, the Patient Treatment File. Controls without cancer were randomly assigned from the Patient Treatment File during the same time period. The inpatient and outpatient files were searched for several conditions including DM, hepatitis C virus (HCV), hepatitis B virus (HBV), alcoholic cirrhosis, autoimmune hepatitis, hemochromatosis, and nonspecific cirrhosis. Adjusted odds ratios (OR) were calculated in a multivariable logistic regression model. RESULTS: We identified 823 patients with PLC and 3459 controls. The case group was older (62 yr [+/-10] vs 60 [+/-11], p < 0.0001), had more men (99% vs 97%, 0.0004), and a greater frequency of nonwhites (66% vs 71%, 0.0009) compared with controls. However, HCV- and HBV-infected patients were younger among cases than controls. Risk factors that were significantly more frequent among PLC cases included HCV (34% vs 5%, p < 0.0001), HBV (11% vs 2%, p < 0.0001), alcoholic cirrhosis (47% vs 6%, p < 0.0001), hemochromatosis (2% vs 0.3%, p < 0.0001), autoimmune hepatitis (5% vs 0.5%, p < 0.0001), and diabetes (33% vs 30%, p = 0.059). In the multivariable logistic regression, diabetes was associated with a significant increase in the adjusted OR of PLC (1.57, 1.08-2.28, p = 0.02) in the presence of HCV, HBV, or alcoholic cirrhosis. Without markers of chronic liver disease, the adjusted OR for diabetes and PLC was not significantly increased (1.08, 0.86-1.18, p = 0.4). There was an increase in the HCV adjusted OR (17.27, 95% Cl = 11.98-24.89) and HBV (9.22, 95% CI = 4.52-18.80) after adjusting for the younger age of HCV- and HBV-infected cases. The combined presence of HCV and alcoholic cirrhosis further increases the risk with an adjusted OR of 79.21 (60.29-103.41). The population attributable fraction for HCV among hospitalized veterans was 44.8%, whereas that of alcoholic cirrhosis was 51%. CONCLUSION: DM increased the risk of PLC only in the presence of other risk factors such as hepatitis C or B or alcoholic cirrhosis. Hepatitis C infection and alcoholic cirrhosis account for most of PLC among veterans.

Carcinoma, Hepatocellular↗
PubMed1995

Therapeutic imagery and athletic injuries.

The rehabilitation process of an injured athlete can be accelerated if clinicians will use an imagery model in conjunction with existing therapeutic care. There is sufficient evidence to suggest a positive relationship between imagery and the healing process. Thus, we provide athletic trainers and practicing clinicians with basic information relating to the use of imagery in rehabilitation. Specifically, a sample imagery program is discussed incorporating the following prescribed steps: introducing imagery to the athlete, evaluating the athlete's imaging ability, assisting the athlete in developing basic imagery skills, and providing tips on the adjunctive use of imagery in a rehabilitation program.

Journal Article↗
PubMed1988

Hormonal profiles and embryo quality in women with severe endometriosis treated by in vitro fertilization and embryo transfer.

A study was undertaken comparing the outcomes of 30 women with infertility due to untreated severe (grade IV) pelvic endometriosis with a comparable series of 28 women whose infertility was caused solely by irreversible tubal disease. There were no significant differences in either the follicular phase or luteal phase hormonal profiles of estradiol and progesterone, but there was a significantly reduced pregnancy rate in those women with severe endometriosis. In part, this was due to the recovery of fewer oocytes from the endometriosis patients (P less than 0.001) despite the fact that the peak estradiol levels and ovarian accessibility were similar in the two groups. However, there were no significant differences in the proportion of oocytes that fertilized or the number that demonstrated normal embryo growth and high-grade embryo quality. There also appears to be an implantation inhibitory factor in patients with severe endometriosis as the pregnancy rate/embryo transferred and number of gestational sacs identified/embryo transferred were significantly reduced (P less than 0.05).

Embryo Transfer↗
PubMed1988

The treatment of normospermic infertility by gamete intrafallopian transfer (GIFT).

Gamete intrafallopian transfer (GIFT) was applied in 207 treatment cycles in 73 couples. The pregnancy rate in cycles with only one (2/21, 9.5%) or two (2/29, 6.9%) oocytes transferred was significantly less than that in which four oocytes (36/116, 31.0%) were replaced. The collection of more than four oocytes did not influence the pregnancy rate in that treatment cycle. The overall pregnancy rate was 24.2% (50 of 207) and was similar in the four infertility groups studied (non-occlusive tubal disorders, endometriosis, cervical factor and unexplained infertility) with 28 (56%) of the pregnancies delivered at greater than or equal to 20 weeks. The pregnancy wastage included 4 (8%) ectopic pregnancies and 3 (6%) late pregnancy losses. The 12 multiple pregnancies occurred following the transfer of three and four oocytes.

Fallopian Tubes↗
PubMed1987

The role of gamete intrafallopian transfer (GIFT) in the treatment of oligospermic infertility.

Gamete intrafallopian transfer (GIFT) was used to treat 32 couples where the male partner was oligospermic (less than 12 X 10(6) motile spermatozoa per milliliter of semen). Initially, 100,000 motile spermatozoa were transferred per fallopian tube and no pregnancies were achieved in 11 cases. The technique was then modified so that a maximal number of motile spermatozoa were transferred (range, 0.11 to 0.90 X 10(6) spermatozoa) and 6 of 21 (29%) pregnancies resulted, with 325,000 spermatozoa being the lowest number associated with pregnancy. It appears that the modified GIFT technique, whereby an increased number of motile spermatozoa are replaced with the oocytes, is an effective therapy in the treatment of oligospermic infertility.

Fallopian Tubes↗
PubMed1987

Pregnancies following pronuclear stage tubal transfer.

Pronuclear stage tubal transfer (PROST) is a technique that involves in vitro fertilization (IVF) of oocytes, followed by the transfer of pronuclear oocytes into the fallopian tubes. It has been developed for its prognostic value of confirming fertilization in couples with oligospermia or asthenospermia and enabling fertilization in cases with antispermatozoal antibodies (ASAB). PROST has provided useful diagnostic information in the management of couples who have failed to conceive in other treatment programs and has particular advantages over IVF for those receiving fresh donated oocytes for ovarian failure. Fourteen pregnancies resulted from 52 transfers, providing a pregnancy rate of 27% per transfer. The pregnancy rates were higher than a matched IVF series in the male factor and female ASAB groups and reached statistical significance for the ovum donation group. It is anticipated that both pregnancy rates and fetal wastage will be improved over conventional IVF and embryo transfer for the described infertility groups.

Antibodies↗
PubMed1982

Percutaneous nephrostomy in a child with obstructive uropathy.

The advantages of percutaneous nephrostomy include (1) achieving rapid, safe drainage of an obstructed collecting system with use of local anesthesia and sedation rather than general anesthesia, and (2) facilitating use of antegrade pyelography under fluoroscopic guidance to determine the cause of the obstruction. In addition, during temporary diversion the functional status of the obstructed kidney can be evaluated. If function is adequate, a pyeloplasty or reimplantation of a ureter may supplant nephrectomy. Use of percutaneous nephrostomy is a relatively new technique for treatment of obstructive uropathy in children. In the case reported here of an 8-year-old girl with a duplicated right collecting system and distal obstruction of the upper pole ureter, the procedure offered a rapid and safe alternative to surgical insertion of a nephrostomy tube.

Child↗