Biomedical subjects

H W Baker

Publications and source records attributed to H W Baker.

At least 127 records · Page 7Linked to original sources

PubMed1987

Variable androgen receptor levels in infertile men.

Labeled methyltrienelone was used to determine androgen receptor (AR) levels in cultured pubic skin fibroblasts in 40 infertile men with primary seminiferous tubule disorders and 18 normal men. LH pulse patterns and mean serum LH levels were also determined by blood sampling at 10-min intervals for 6 h. The infertile men and the normal men had similar mean receptor levels [mean, 28.1 +/- 2.0 (+/- SEM) and 24.8 +/- 1.8 fmol/mg protein, respectively]. However, 5 men with chromosomal disorders had a higher mean AR level (41.3 +/- 6.2 fmol/mg protein) than the normal men, and 5 of the remaining infertile men (14.2%) had receptor levels that were less than the minimum value in normal men. In men with idiopathic oligospermia, 19.0% had low receptor levels. Although mean serum FSH and testosterone levels were similar in the infertile men with low AR levels and in the normal men, mean LH levels were significantly elevated in this group (7.1 vs. 3.6 IU/L), the higher values being a result of increased LH pulse amplitude (mean, 5.6 vs. 2.8 IU/L). The LH-testosterone product (an index of androgen resistance) was also elevated in these men. When infertile men with low AR levels were matched with infertile men with normal receptor levels, the mean LH values were significantly elevated in the former, as was the LH-testosterone product. Testosterone values were similar in the two groups of men. After excluding subjects with chromosomal disorders, there were no significant correlations between AR levels and other indices of androgen action, such as semen volume, seminal fructose, or sex hormone-binding globulin levels. We conclude that AR levels are higher in patients with severe testicular failure associated with X-chromosome disorders. Also, AR defects were found in 19.0% of infertile men with idiopathic oligospermia. Finally, elevation of mean LH levels in men with seminiferous tubule disorders may reflect resistance to androgen action.

Adult↗

PubMed1987

Mild to moderate abnormalities of semen do not affect pregnancy rates during ovulation induction with gonadotrophins.

One or more semen analysis results were available for 195 men whose wives responded to ovulation induction with gonadotrophins performed at The Royal Women's Hospital since 1963. Fifty-three men (27%) has subnormal semen analyses by conventional criteria: sperm concentration less than or equal to 20 X 10(6)/ml, motility less than or equal to 40% or normal morphology less than or equal to 50%. The lifetable pregnancy rates were not significantly different for those with subnormal and normal semen (chi 2 = 0.169), by six cycles 64% (s.e.m. = 7) with subnormal semen had conceived compared with 59% (s.e.m. = 5) with normal semen. It appears that lower limits of semen quality could be relaxed for women needing ovulation induction with gonadotrophins.

Female↗

PubMed1987

Spermatozoal nuclear chromatin decondensation in vitro: a test for sperm immaturity. Comparison with results of human in vitro fertilisation.

Human sperm immaturity was tested by nuclear chromatin decondensation (NCD) in 1% sodium dodecylsulphate (SDS) of spermatozoa used in 74 consecutive IVF treatments. NCD was significantly higher in the presence of 2 mmol/l dithiothreitol (DTT) and after washing sperm from semen with 6 mmol/l ethylenediaminetetraacetic acid (EDTA). NCD was significantly less in insemination suspensions prepared by the swim-up technique than in the original semen. NCD with DTT was inversely correlated with sperm motility and motility index but there were no significant relationships between NCD and other semen analysis variables. There was no significant correlation between any NCD test and the proportion of oocytes fertilised in vitro. The only factors being significantly correlated with the fertilisation rate were proportion of sperm with normal morphology (Kendall correlation, tau = 0.36, P less than 0.001) and sperm concentration (tau = 0.14, P less than 0.05). Logistic regression analysis of fertilisation rates showed that only percentage normal sperm morphology was significant. It is concluded that NCD does not provide additional useful clinical information about sperm fertilising ability in vitro.

Cell Nucleus↗

PubMed1987

Comparison of latex and polyacrylamide beads for detecting sperm antibodies.

The immunobead test is excellent for the routine screening of semen for sperm antibodies but the polyacrylamide beads currently used are of variable diameter (3-10 micron) which tends to obscure details of regional binding. Thus the use of smaller latex beads of more uniform diameter has been investigated. Latex beads were coated with IgG by exposure to anti D serum for a mixed antiglobulin reaction (MAR). Rabbit antihuman IgG and IgA antibodies were covalently bound to carboxylated latex microspheres (CLM) by the carbodiimide reaction. Polyacrylamide immunobeads (IBT) with antihuman IgG or IgA antibodies covalently attached were obtained commercially. The IgG IBT and MAR were compared in 55 samples. The MAR was positive in 15 of the 31 IBT positive samples but the proportion of sperm with attached beads was lower. CLM and IBT were compared in 106 samples. Both tests were positive in 34 samples with virtually identical proportions of motile sperm with beads attached and the patterns of attachment were similar. These results show that CLM microspheres give equivalent results to IBT and that as they are smaller and have a more uniform size they provide advantage in ease of detection of positive reactions and in determination of the regional blinding pattern.

Acrylic Resins↗

PubMed1986

In-vitro fertilization and embryo transfer. Prospects of pregnancy by life-table analysis.

Data have been analysed for 1775 laparoscopies that were undertaken for the collection of oocytes, and for 1401 embryo transfers that were undertaken for the treatment of infertility by in-vitro fertilization, by the Monash University in-vitro fertilization unit team. The cumulative success rates with multiple attempts were analysed by life-table analysis and life-table graphs were constructed. Almost half the patients were pregnant after five laparoscopies. These findings suggest that treatment should consist of multiple laparoscopies and that improvements should be aimed at decreasing the morbidity, stress and cost of multiple attempts.

Actuarial Analysis↗

PubMed1986

Thermoradiotherapy for persistent cancer in previously irradiated fields.

Among some 300 patients undergoing clinical trails with localized radiofrequency hyperthermia, 42 whose cancers had persisted or recurred after conventional radiotherapy were selected for additional limited radiation plus hyperthermia. There were 10 complete responses to therapy, 13 partial responses and one patient was considered nonevaluable. In the remaining 18 patients there was minor regression, stabilization or progression of the tumor. After completion of treatment, five of the tumors appeared operable and surgical resection was accomplished in four. The results of this study support the concept that hyperthermia has a potentiating effect when used in conjunction with radiation therapy.

Adenocarcinoma↗

PubMed1986

Biologic control of cancer. The James Ewing lecture.

There is abundant clinical and laboratory evidence that host defenses are a significant factor in the progression and the control of cancer. The host immune system plays the major role, primarily through cell-mediated responses to the neoplastic threat. Great progress has been made in evaluating immune competence, although the specific defects have not been identified in all patients. The history of immunotherapy includes numerous trials, with few successes and many failures. Advances in knowledge and technology, however, indicate that efforts to manipulate and strengthen host defenses have great potential in the fight against cancer.

Adult↗

PubMed1986

Cheek island flap for replacement of critical limited defects of the upper aerodigestive tract.

Our experience thus far indicates that the island cheek flap is a satisfactory reconstructive method for small but critical defects in the upper aerodigestive tract. The mucosal lining is an ideal replacement for the lining of the mouth, pharynx, and esophagus. Only a single stage procedure is required. The surgical technique is relatively simple and does not unnecessarily prolong an extensive operation for tumor resection. We have found the procedure to be reliable with no instances of flap loss or necrosis.

Cheek↗

PubMed1986

Aggressive surgical management of pyriform sinus carcinoma. A 15 year experience.

A total of 51 patients with pyriform sinus carcinoma were treated surgically. Fifty had pharyngolaryngectomy and radical neck dissection and 1 had a pharyngolaryngectomy. The surgical mortality was zero. No patients were lost to follow-up and all were followed for a minimum of 2 years. Stage IV patients had a 2 year survival rate of 15 percent and stage III patients, a 45 percent rate. Eighty-four percent of radical neck specimens contained involved nodes. The 2 year survival rates correlated with the number of pathologically involved nodes were as follows: 50 percent for those with zero to one node, 31 percent for two to three nodes, and 16 percent for four or more nodes. Perioperative radiotherapy increased the survival rate in those patients with zero to three involved nodes (47 percent survival rate with radiotherapy versus 25 percent without radiotherapy). Tumor recurrence was most frequent at the primary site (32 percent) and directly affected survival and control of disease elsewhere. Pyriform sinus carcinoma often presents with advanced local and nodal disease. Local control is essential, and adequate resection may require a cervical esophagectomy. Survival may be enhanced by the addition of radiotherapy in those patients with minimal nodal involvement.

Carcinoma, Squamous Cell↗

PubMed1986

Is there a specific abnormality of sperm morphology in men with varicoceles?

With the use of a case-control design, we have studied seminal cytology in 53 infertile men with large left varicoceles to determine whether they had a specific morphologic pattern. An equal number of infertile controls without varicoceles were matched for characteristics such as left testicular size, serum follicle-stimulating hormone levels, and sperm concentration to ensure similar degrees of testicular dysfunction. No significant difference in the morphologic patterns was observed, especially in the hallmarks of the "stress pattern": increased percentages of spermatozoa with tapering heads (1.8 +/- 2.6:1.9 +/- 4.0) and immature forms (8.1 +/- 5.4:6.4 +/- 2.9) in the varicocele and control groups, respectively. Assessment of morphologic characteristics was associated with wide errors (approximately 20% to 80%) among technicians working in the same laboratory. There does not appear to be a characteristic morphologic stress pattern in infertile men with large left varicoceles.

Adult↗

PubMed1986

The effect of serum on motility of human spermatozoa in culture.

The motility of spermatozoa was higher at 6-22 h in Ham's F10 culture medium supplemented with 20-30% human serum than with lower proportions of serum or with 1% human serum albumin. Heat treatment (56 degrees C, 1 h), charcoal extraction and dialysis (18,000 molecular weight cut-off) of the serum did not reduce sperm motility suggesting that high molecular weight components are responsible for maintenance of motility. Renewing the medium (Ham's F10 with 30% serum) at 7 h resulted in better sperm motility and velocity at 22 h. At 22 h the pO2, pCO2, pH and sodium concentrations were not different in replenished and control cultures, but the concentration of glucose was higher and that of potassium lower if the medium was changed. These results suggest that addition of 20-30% human serum and renewal of medium at intervals is beneficial for sperm culture and may be of use in in vitro fertilization.

Blood↗

PubMed1986

The contraceptive diaphragm. Is it an acceptable method in the 1980s?

A prospective study of diaphragm users at the Family Planning Association of Victoria was undertaken. Despite the women being well motivated and instructed the pregnancy rate was high (24 per 100 woman years) and the continuation rate was only 35% at 12 months. Three-quarters of the women who became pregnant admitted that they did not use a diaphragm on every occasion. Therefore emphasis must be placed on the committed use of the diaphragm every time coitus occurs. Even so, the diaphragm does not appear to be a very safe method of contraception, and may be better suited to family spacing rather than as a method when high efficacy is required.

Contraception Behavior↗

PubMed1986

Timing of ovulation by determination of the urinary luteinizing hormone surge with an enzyme-linked monoclonal antibody dipstick (OvuStick).

An enzyme-linked double monoclonal antibody dipstick for measuring luteinizing hormone in urine was tested for timing ovulation in thrice daily urine samples collected for several days around mid-cycle in 24 women undergoing artificial insemination. The assay produced information comparable to single daily serum LH measurements. The dipsticks could be used by untrained people to test their own urine as an aid to the detection of ovulation for the timing of artificial insemination or of sexual intercourse to promote or avoid conception.

Antibodies, Monoclonal↗

PubMed1986

Immobilization of sperm by condoms and their components.

Condoms and other rubber products immobilize sperm, but the mechanism is unknown. Sperm motility and eosin Y exclusion were measured following exposure of samples of semen to latex condoms of various types. Sperm motility was markedly reduced by exposure to all latex condoms, but eosin Y exclusion was unchanged. While there appeared to be some variability between semen samples and in time to complete immobilization of all sperm, condoms from one batch were similar. The immobilizing effect was not altered by prewashing the condom with buffer, chelating agent or acid. After immobilization, motility was not recovered by sperm washed in buffer, mixed with normal mid-cycle cervical mucus, or exposed to caffeine or adenosine triphosphate after demembranation with detergent. Studies with components of condoms indicated that raw latex and zinc dimethyl- and dibutyl-dithiocarbamate accelerators immobilized sperm within 30 min. In contrast, silicone rubber had no effect on sperm motility for up to 4 h. Enhancement of the sperm immobilizing effect might improve the contraceptive efficacy of condoms, while a useful non-toxic sperm collecting device for semen analysis, artificial insemination or in vitro fertilisation might be developed by omitting the toxic components from the rubber.

Contraceptive Devices, Male↗

PubMed1986

Partial gonadotrophin deficiency is infrequent in infertile men.

Hormone values and semen analyses were studied in 1761 men referred for evaluation of infertility to determine the frequency of isolated deficiency of either FSH, LH, or partial deficiency of both gonadotrophins. There were 17 men (1%) with oligospermia and FSH values at the lower end of the normal range. Without treatment, four pregnancies occurred in this group. Of the remainder, one was treated with gonadotrophin replacement therapy with no improvement in sperm concentration or motility. One man had possible isolated LH deficiency, but was subsequently found to have normal LH and testosterone values. No case of partial gonadotrophin deficiency was found. It was concluded that isolated deficiency of either FSH, LH, or partial deficiency of both gonadotrophins must be extremely rare as a cause of infertility.

Adult↗

PubMed1986

Requirements for controlled therapeutic trials in male infertility.

The majority of men who present with infertility have oligospermia or asthenospermia which renders them subfertile; pregnancies occur at lower than normal rates. Currently available treatments for this group are of uncertain value. This paper outlines an approach to controlled trials to test old and new methods for their ability to improve semen quality and increase pregnancy rates. As well as careful design, the need for control groups and large numbers of subjects is emphasized. Control groups are necessary because pregnancies and apparent or real spontaneous improvements in semen test results occur without treatment. Trials to evaluate differences in pregnancy rates need to be large because pregnancy rates are low and the margin for improvement narrow. Most untreated infertile couples have average pregnancy rates of less than 5% per month, whereas pregnancy rates in the general community average 20% per month. Under these circumstances, small trials with less than 20 pregnancies are unhelpful as they are not sensitive enough to detect less than threefold differences in pregnancy rates between groups. The number of subjects required for a trial can be calculated or determined from tables or graphs. A 50% difference in pregnancy rates in two groups given alternative treatments only has a high chance of being statistically significant if there are hundreds of subjects achieving a total of approximately 200 pregnancies in the trial. Such large trials can only be performed by several centres collaborating.

Actuarial Analysis↗

PubMed1986

Occupation-related male infertility: a review.

Male infertility is a significant health problem for which few aetiological factors have been identified. The role of occupational exposure is largely unknown but certain substances such as 1,2-dibromo-3-chloropropane, oestrogen, heat, lead and microwaves have been reported to impair spermatogenesis in workers. Other agents which interfere with reproductive performance in experimental animals such as cadmium, manganese, organophosphates and some solvents have not been studied sufficiently for their occupational risks to be fully known. Some occupational exposures, extensively studied, appear to convey little or no risk to male fertility including radiological exposure, anaesthetic gases and Agent Orange. It is clear that the range of substances potentially hazardous to male reproduction is great but the number of agents for which the evidence is unequivocal is very small.

Anesthetics↗

PubMed1986

Is conventional bacteriology useful in the management of male infertility?

An aetiological role for non-specific genital tract infection (GTI) in male infertility has long been postulated and has led to routine bacteriologic culture of semen in some laboratories. To assess the value of examination of various semen characteristics and conventional culture of semen as diagnostic criteria for GTI, frequencies of bacterial isolation and relationships with leukocytospermia and other abnormalities of semen were determined in 806 samples from 459 men seen over a 2 year period. Combinations of features suggestive of GTI were present in 19.6%. High leucocyte counts were found in 13.5% of specimens and evidence of possible accessory sex organ dysfunction in 57.7%. Significant numbers of bacteria were isolated from 19.5% of samples. Of the few pathogens cultured (46 specimens), 53% were Staphylococcus aureus, a possible contaminant. Furthermore, only one specimen had more than 10(6) pathogenic bacteria per ml, also Staph. aureus. There was a lack of correlation between the presence of bacteriospermia, leukocytospermia and semen changes possibly attributable to accessory sex organ dysfunction, shedding doubt on their relevance to identification of GTI. This was the case even in repeatedly culture-positive specimens. Conventional bacteriological examination of semen specimens is not merited as a routine procedure.

Bacteriology↗