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Biomedical subjects

J M Baker

Publications and source records attributed to J M Baker.

At least 37 records · Page 2Linked to original sources
PubMed1997

A phase I comparative study of contraceptive vaginal films containing benzalkonium chloride and nonoxynol-9. Postcoital testing and colposcopy.

Benzalkonium chloride (BZK) has been shown in in vitro and in vivo studies to immobilize sperm, to be active against STD-causing organisms, and to penetrate and thicken cervical mucus. A US clinical study of a sponge containing 60 mg BZK showed life table pregnancy rates at 6 and 12 months of 11.7 and 18.9 per 100 women, respectively. BZK is not currently marketed in the US as a contraceptive. The present study aimed to assess 1) the ability of a new contraceptive vaginal film containing either of two doses of BZK to prevent the penetration of sperm into midcycle cervical mucus; 2) the effect of the film on the vaginal epithelium; and 3) the acceptability of the film. All results were compared with VCF, a currently marketed film containing nonoxynol-9 (N-9). Ten women underwent two baseline cycles of postcoital testing in which no film was used, followed by three test cycles in which Allendale-BZK film, a new film containing either 19 or 25 mg BZK, or VCF, containing 70 mg N-9, was used. The sequence of testing cycles was randomized. In each cycle, condoms were used prior to midcycle, then a midcycle cervical mucus specimen was examined to ensure midcycle characteristics and the absence of sperm. Each woman then had intercourse using either no film (baseline cycles) or a test film (test cycles) and returned 2-3 h afterwards. Cervical mucus was again assessed for adequacy and the presence of sperm. Each woman also underwent colposcopy, using a protocol developed by the World Health Organization. The average number of progressively motile sperm seen per high power field was as follows: first baseline cycle, 22.2; second baseline cycle, 22.1; test cycle with film containing 19 mg BZK, 0.2; test cycle with film containing 25 mg BZK, 0.0; and test cycle with VCF containing 70 mg N-9, 0.0. There was no significant difference between baseline cycles or among test cycles in the average number of progressively motile sperm seen (p = 0.78 and p > or = 0.75, respectively). The average number of progressively motile sperm seen in each test cycle did, however, differ significantly from the average number seen in either baseline cycle (p < 0.01). Colposcopy showed superficial de-epithelialization without underlying inflammation in 15-20% of baseline cycles, regardless of whether colposcopy was done before or after coitus; in 50% of cycles in which either dose of BZK was used; and in 69% of cycles in which VCF was used. In all cases women were asymptomatic. Erythema and petechiae were also seen on colposcopy although at a lower frequency than de-epithelialization. There was no difference in the acceptability of the films. A vaginal contraceptive containing either 19 or 25 mg BZK in a new film base appears to be comparable with VCF in preventing sperm from entering midcycle cervical mucus and may be somewhat less disruptive to the vaginal epithelium.

Administration, Intravaginal↗
PubMed1997

A phase I study of Femcap used with and without spermicide. Postcoital testing.

The objectives of the study were to assess the ability of the Femcap, a new vaginal contraceptive device made of silicone and designed to fit snugly around the cervix to prevent the penetration of sperm into midcycle cervical mucus when used with and without spermicide; and to compare it with the standard contraceptive diaphragm used with spermicide. Eight women underwent two baseline cycles of postcoital testing in which no device was used, followed by three test cycles in which Femcap with spermicide, Femcap with nonspermicidal lubricant (K'Y gel) or the Ortho All-Flex diaphragm with spermicide was used. The sequence of testing cycles was randomized. In each cycle, condoms were used prior to midcycle, then a midcycle cervical mucus specimen was examined to ensure midcycle characteristics and the absence of sperm. Each woman then had intercourse using either no device (baseline cycles) or the prescribed device (test cycles) and returned 2-3 h afterwards. Cervical mucus was again assessed for adequacy and the presence of spermatozoa. The average number of progressively motile sperm seen per high power field was as follows: first baseline cycle, 18.0; second baseline cycle, 17.8; test cycle with Femcap used with nonspermicidal lubricant, 0.1; test cycle with Femcap used with spermicide, 0.2; and test cycle with the diaphragm used with spermicide, 0.0. There was no significant difference between baseline cycles or among test cycles in the average number of progressively motile sperm seen (p > 0.05). The average number of progressively motile sperm seen in each test cycle did, however, differ significantly from the average number seen in either baseline cycle (p < 0.05). Femcap, used with either a spermicidal lubricant or a nonspermicidal lubricant, appears to be comparable with the diaphragm used with spermicide in preventing sperm from entering midcycle cervical mucus.

Cervix Mucus↗
PubMed1997

A phase I comparative study of three contraceptive vaginal films containing nonoxynol-9. Postcoital testing and colposcopy.

The objectives of this study were 1) to assess the ability of a new contraceptive vaginal film containing two doses of nonoxynol-9 (N-9) to prevent the penetration of sperm into midcycle cervical mucus, and 2) to determine the effect of the film on the vaginal epithelium. The novel formulation was compared with VCF (a currently marketed film also containing N-9). Ten women underwent two baseline cycles of postcoital testing in which no film was used, followed by three test cycles in which Allendale-N9 film, a new film containing either 100 or 130 mg N-9, or VCF containing 70mg N-9 was used. The sequence of testing cycles was randomized. In each cycle, condoms were used prior to midcycle, then a midcycle cervical mucus specimen was examined to ensure midcycle characteristics and the absence of sperm. Each woman then had intercourse using either no film (baseline cycles) or a test film (test cycles) and returned 2-3 h afterwards. Cervical mucus was again assessed for adequacy and the presence of sperm. Each woman also underwent colposcopy using a protocol developed by the World Health Organization. The average number of progressively motile sperm seen per high power field were as follows: average of the two baseline cycles, 19.3; test cycle with Allendale-N9 film containing 100 mg N-9, 0.6; test cycle with Allendale-N9 film containing 130 mg N-9, 0.9; and test cycle with VCF, 0.5. There was no significant difference between baseline cycles or between test cycles in the number of progressively motile sperm per high power field (HPF) seen (p = 0.31 and p > or = 0.50, respectively). The average number of motile sperm seen in each test cycle did, however, differ significantly from the number in either baseline cycle (p < 0.02). The majority of colposcopic examinations were normal. In one baseline cycle and eight test cycles, colposcopy showed superficial de-epithelialization without underlying inflammation. There was no apparent dose response and in all cases the volunteers were asymptomatic. A vaginal contraceptive containing either 100 or 130 mg N-9 in a new film base appears to be safe and comparable to VCF in preventing sperm from entering midcycle cervical mucus.

Administration, Intravaginal↗
PubMed1997

An evaluation of the amount of nonoxynol-9 remaining in the vagina up to 4 h after insertion of a vaginal contraceptive film (VCF) containing 70 mg nonoxynol-9.

The objectives of this study were to determine the amount of nonoxynol-9 (N-9) remaining in the vagina 30 min and 1, 1.5, 2, and 4 h after vaginal insertion of a single sheet of VCF containing 70 mg N-9 and to compare these results to the manufacturer's instructions for use of this product. A new method of vaginal lavage was used to obtain samples for N-9 determination. This was an open-label, noncomparative, pharmacokinetic study in 12 healthy women volunteers not at risk for pregnancy. The study consisted of a screening visit followed by five test visits approximately 1 month apart and a final visit 1 week after all test visits were completed. At each test visit, the investigator inserted a single sheet of VCF in the vagina of the volunteer at midcycle. The volunteer remained in the clinic and underwent vaginal lavage with normal saline after one of five specified time intervals had elapsed. The sequence of the intervals completed by each volunteer was determined by randomization. When undissolved film was found in the vagina, it was removed prior to lavage and assayed for N-9 content separately from that recovered in lavage fluid. It was assumed that the N-9 in undissolved film would not contribute significantly to sperm immobilization. Between 18.5 and 28.5 mg of N-9 were recovered in lavage fluid after intervals of 0.5, 1, 1.5, and 2 h. These levels did not differ statistically (p > 0.05). The amount of N-9 recovered dropped significantly at 4 h to 11.0 mg. If it is assumed that an N-9 concentration of 0.100 mg/mL is required to immobilize sperm in vitro, this study suggests that the amount of N-9 remaining in the vagina in the form of dissolved film up to 4 h after insertion of VCF is sufficient to immobilize sperm. The lavage procedure may not have recovered all N-9 remaining in the vagina. However, intercourse did not take place between insertion and lavage; if it had, the proportion of the film remaining undissolved and the total amount N-9 remaining in the vagina at the time of examination might have been affected.

Administration, Intravaginal↗
PubMed1997

A practical guide to surgical loupes.

Loupes are widely used in both surgical and dental procedures to enhance visualization of tissues and to facilitate optimal instrument placement. Most doctors, however, have limited knowledge of fundamental optical principals or of the various types of loupes available. This article reviews basic optical terminology and principles and highlights features of various commercially available loupes.

Equipment Design↗
PubMed1997

Steroid pretreatment improves graft recovery in a sheep orthotopic heart transplantation model.

BACKGROUND: Previous reports provide conflicting evidence concerning effects of steroids on recovery of cardiac function during procedures involving cardiopulmonary bypass. This study was designed to test the hypothesis that pretreatment of animals with steroids before heart transplantation improves graft hemodynamic function. METHODS: Four groups of sheep were studied: CON, nonsteroid-treated nontransplanted controls (n = 8); CON-S, steroid-treated nontransplanted controls (n = 5); TX, nonsteroid-treated transplanted animals (n = 5); and TX-S, steroid-treated transplanted animals (n = 5). Steroid-treated animals were given methylprednisolone 30 mg/kg immediately before surgery. Procedures for harvest and orthotopic transplantation were similar to those used clinically. Contractile function, left ventricular diameter, and cardiac output of control and transplanted hearts were measured for 6 hours. A 2 x 2 factorial repeated measures analysis of variance was used to determine statistical significance (p < 0.05). RESULTS: Steroid pretreatment produced significantly higher function in controls and transplanted animals compared with nonsteroid-treated animals. On average over 6 hours, significant steroid effects were observed for left ventricular peak systolic pressure, mm Hg (CON, 85 +/- 2; CON-S, 98 +/- 3; TX, 74 +/- 3; TX-S, 91 +/- 2); global stroke work, mJoule x cm(-2) (CON, 4.69 +/- 0.21; CON-S, 5.88 +/- 0.32; TX, 2.27 +/- 0.17; TX-S, 4.23 +/- 0.16); and peak rate of pressure relaxation (-dP/dt(max)), mm Hg/msec (CON, 1.23 +/- 0.05; CON-S, 1.44 +/- 0.08; TX, 0.60 +/- 0.03; TX-S, 2.04 +/- 0.13). Steroid pretreatment produced more stable recovery for transplanted animals. All five TX-S animals could be removed from inotropic support and had stable function for 6 hours. In contrast, 1 of 5 TX animals could not be removed from inotropic support, and 1 of 5 TX hearts failed 3 hours after transplant. Arterial blood PO2 values were significantly higher in steroid-treated animals than in nonsteroid treated animals. Blood systemic lactate, which was elevated after transplantation, returned to control level by 6 hours in the steroid-treated group but not in the nonsteroid-treated group. CONCLUSION: Steroid pretreatment of heart donors and recipients improved systolic and diastolic function and hemodynamic stability after transplantation. In addition, steroid pretreatment improved pulmonary gas exchange of control and transplanted animals.

Animals↗
PubMed1996

Idiom understanding in Australian youth: a cross-cultural comparison.

In this developmental study, idiom understanding was examined in Australian students from Grades 5 and 8 (n = 50 per group; mean ages = 10.7 and 13.8, respectively). Twenty-four idioms with familiarity ratings ranging from high to low (as judged by Australian adolescents) were each presented in a brief story context. The students read each story and selected the best interpretation of the idiom from a set of four answer choices. Results indicated that performance on the task improved as a function of increasing grade level and that idiom familiarity was significantly correlated to idiom understanding for both groups of students. These results, which were consistent with a previous study of American students of comparable educational levels (Nippold & Taylor, 1995), provide further support for the "language experience" hypothesis of figurative language development. In replicating the previous developmental study, evidence of external validity is provided.

Adolescent↗
PubMed1996

Hypnosis training in psychology intern programs.

The use of hypnosis is becoming increasingly common in clinical practice. This article examines hypnosis training in psychology internship programs. A survey was sent to all APA intern programs listed in the APPIC directory requesting information about opportunities for training and utilizing hypnosis during the intern year. Thirteen percent of responding programs (n = 424) reported regular seminars in hypnosis, while another 37% offer elective opportunities. However, of those programs that provide training, the average amount of time was approximately seven hours. The authors conclude that while training is provided to a significant percentage of interns, the amount of time is not enough to allow for its ethical use. It is suggested that as the use of hypnosis increases, training programs may want to consider opportunities for more adequate hypnosis training.

Curriculum↗
PubMed1996

A national survey of hypnosis training--its status in psychiatric residency programs: a brief communication.

Hypnosis training in psychiatric residency programs has not previously been well documented in the literature. This article examines the extent of such training in residency programs and the attitudes of residency directors to training and the use of hypnosis. A brief survey requesting information on hypnosis training was sent to all psychiatric residency directors in the United States. Sixty-three percent of responding program directors (n = 154) report offering either required or elective coursework in hypnosis. Of programs offering hypnosis training, the mean number of hours was 8, suggesting that many psychiatrists have only limited exposure to hypnosis during residency. The authors conclude that hypnosis training is widely variable within psychiatric residency programs and is dependent on the faculty and training director interests within individual programs.

Attitude of Health Personnel↗
PubMed1994

Loss of heterozygosity and decreased expression of NME genes correlate with teratomatous differentiation in human male germ cell tumors.

Embryonal carcinoma in the human male is a pluripotential germ cell tumor (GCT), which is suggested to further differentiate to teratoma which displays somatic differentiation representing all three germinal layers. In a panel of 37 GCTs we determined frequency of loss of heterozygosity (LOH) and the level of expression of nucleoside diphosphate kinase (NDPK) genes NME 1 and NME 2. The frequency of LOH in teratomas (86%) was found to be highly significant (P < 0.01) compared to embryonal carcinomas (17%). We also found that the NME encoded proteins are expressed at a 4-5 fold lower level in teratomas compared to embryonal carcinomas. These findings lead us to hypothesize that a critical level of NDPK may be necessary for suppression of aberrant somatic differentiation.

Gene Expression↗
PubMed1994

Crigler-Najjar disease in pregnancy.

BACKGROUND: Crigler-Najjar disease, a rare cause of maternal unconjugated hyperbilirubinemia in pregnancy, poses no threat to the mother, and the elevated bilirubin levels do not seem harmful to the fetus. However, the disease is expressed in two forms, one of which is fatal. CASE: The maternal total bilirubin (mostly unconjugated) was 8.5 mg/dL in the first trimester, fell to 5.0 mg/dL in the second, and rose again to 8.8 mg/dL at term. The infant was jaundiced at birth, with umbilical cord total bilirubin at 7.6 mg/dL. The jaundice resolved without treatment, and no sequelae of hyperbilirubinemia were present. CONCLUSION: Crigler-Najjar disease type II seems to pose no unique maternal risk during pregnancy. The fetus seems to be resistant to elevated maternal unconjugated bilirubin, but the neonate may required therapy for hyperbilirubinemia.

Adult↗
PubMed1990

Detection of primary colorectal cancer with indium 111 monoclonal antibody B72.3.

B72.3 is a murine monoclonal antibody of the immunoglobulin subclass IgG1 directed against TAG-72, a cell surface antigen present on colorectal carcinoma cells. We investigated the utility of scanning with indium 111-labeled B72.3 in 16 patients with a high clinical suspicion of or biopsy-proven primary colorectal cancer. Each patient received 1 or 2 mg of B72.3 monoclonal antibody labeled with 152 MBq of indium 111. Patients underwent scanning 2 to 3 days and 7 days after infusion by planar and emission computed tomography. Nineteen lesions were confirmed in 12 patients. Three patients with benign polyps had true-negative monoclonal antibody scans. Indium 111-labeled imaging of B72.3 detected nine of 19 lesions. Unsuspected tumor sites were identified by monoclonal antibody scan in three patients. By detection of additional abdominal disease and extra-abdominal spread, indium 111-labeled scanning of B72.3 directly affected treatment in 18% of patients.

Adenocarcinoma↗
PubMed1990

Are regular education classes equipped to accommodate students with learning disabilities?

This study examined educational practices in regular education classes in grades K-5 to determine changes required to facilitate a full-time mainstreaming program for students with learning disabilities. Data collected during the planning year of a mainstreaming project permitted a detailed analysis of the elementary school and the extent to which it accommodated individual differences. Data from informal and structured observations, interviews, and surveys of students, parents, and teachers suggested that fundamental changes in instruction are necessary for the regular education initiative to work in this school.

Achievement↗
PubMed1988

Fine-needle aspiration cytology monitoring of elective conversion from cyclosporin to azathioprine and prednisolone.

The elective conversion of renal allograft recipients from cyclosporin (CsA) to azathioprine and prednisolone has the advantage that the long-term risk of CsA nephrotoxicity is reduced, but it may precipitate a rejection episode. We have monitored this period by fine-needle aspiration cytology (FNAC) in 24 patients undergoing conversion of immunosuppression 6 months after transplantation. As expected the serum creatinine and alkaline phosphatase were significantly reduced and the mean creatinine clearance was significantly increased after conversion. FNAC exhibited increased mononuclear cellular infiltration in 13 of the 24 patients. In nine patients there was a transient infiltration of lymphocytes and monocytes without changes in the normal parameters of renal function. In four others 'blast' cell infiltration was evident in association with rejection episodes. All four responded to pulsed doses of methylprednisolone. However, two other patients had late rejection episodes (2 and 6 months after conversion) which were steroid resistant and required reintroduction of CsA. No grafts were lost (median follow-up 9 months). This study has shown that although overt rejection occurred in only 16.6% of patients, cellular infiltration was present in over 50% during conversion of immunosuppression. FNAC failed to identify clearly the patients at risk of rejection during conversion of therapy.

Adolescent↗
PubMed1987

Cerebellar metastases from epithelial ovarian carcinoma. A case report.

Central nervous system metastases are an unusual sequela of epithelial ovarian neoplasms, occurring in less than 1% of reported autopsy cases. A case of cerebellar metastatic disease occurred following combination chemotherapy and a negative second-look operation for a stage III poorly differentiated adenocarcinoma of the ovary. The single metastatic tumor was resectable, and the patient had resolution of her symptoms following surgery. This is the fourth report of an epithelial ovarian carcinoma metastatic to the cerebellum.

Aged↗
PubMed1986

Pharmacokinetics and metabolism of 14C-tinidazole in humans.

Following intravenous infusion of 800 mg of 14C-tinidazole during 30 min to two human subjects, a mean of 44% of the dose was excreted in urine during the first 24 h, increasing to 63% of the dose during five days: 12% of the dose was excreted in the faeces, indicating the possible involvement of biliary excretion and other secretory processes in the disposition of tinidazole. At 6 min after the end of the infusion, the mean plasma tinidazole concentration was 12 mg/l. Tinidazole was a major component in 0-120 h urine (about 32% of urinary 14C): the major metabolite in the 0-12 h urine examined was ethyl 2-(5-hydroxy-2-methyl-4-nitro-1-imidazolyl)ethyl sulphone (about 30% urinary 14C), the product of hydroxylation and nitro-group migration. These compounds were also present in the faeces. A minor urinary metabolite was 2-hydroxymethyltinidazole (about 9% urinary 14C), which was also present in plasma. The mean pharmacokinetic parameters obtained for tinidazole were similar to those reported in the literature; total clearance 51 ml/min, renal clearance 10 ml/min, volume of distribution 501 and half-life 11.6 h.

Adult↗
PubMed1984

Assay of cytotoxicity and mutagenicity of alkylating agents by using Neurospora spheroplasts.

A system relying on the use of Neurospora crassa spheroplasts has been developed for the assay of cytotoxicity and mutagenicity of chemical compounds. Mutagenicity was assayed by using reversion of alleles in the am gene selected to recognize certain specified transitions and also undefined point mutations. Cytotoxicity was quantified by measuring a 'cytotoxicity parameter', m, which appears in the exponential function that fits the survival/dose curve for each compound (under standard incubation conditions). Of the compounds tested, nitrogen mustard (Cl(CH2)2 NMe(CH2)2Cl) was cytotoxic and non-mutagenic, and ethyl nitrosourea was highly mutagenic but not cytotoxic. Of the remaining compounds tested, methyl nitrosourea, butadiene diepoxide, and cis platin (cis diammonia platinum II chloride) all showed comparable mutagenicity per survivor, although the values of m covered a wide range. Differences were found between the different compounds in the effects of the uvs-2 allele on survival and on the preponderance of G to A transitions.

Alkylating Agents↗