Infection rate and colonization with antibiotic-resistant organisms in skilled nursing facility residents with indwelling devices.

The objective of this prospective surveillance study was to quantify colonization with antimicrobial-resistant organisms (AROs) and infections attributable to indwelling devices in skilled nursing facility (SNF) residents. The study was conducted in 15 SNFs in Southeast Michigan. Residents with (n=90) and without (n=88) an indwelling device were enrolled and followed for 907 resident-months. Residents were cultured monthly from multiple anatomic sites and data on infections were obtained. The device-attributable rate was calculated by subtracting the infection rate in the device group from the infection rate in the non-device group. A total of 197 new infections occurred during the study period; 87 in the device group (incidence rate [IR] =331/1,000 resident-months) and 110 infections in the non-device group (IR=171/1,000 resident-months), with a relative risk of 1.9 (95% confidence interval [CI]: 1.4-2.6). The attributable rate of excess infections among residents in the device group was 160/1,000 resident-months, with an attributable fraction of 48% (95% CI: 31-61%). Prevalence rates for all AROs were higher in the device group compared with the no-device group. The prevalence of the number of AROs per 1,000 residents cultured increased from no-device to those with only feeding tubes, followed by those with only urinary catheters and both these devices. In conclusion, the presence of indwelling devices is associated with higher incidence rates for infections and prevalence rates for AROs. Our study quantifies this risk and shows that approximately half of all infections in SNF residents with indwelling devices can be eliminated with device removal. Effective strategies to reduce infections and AROs in these residents are warranted.

Influence of early ICSI-derived embryo sHLA-G expression on pregnancy and implantation rates: a prospective study.

BACKGROUND: We have previously reported the retrospective observation that when at least one embryo, transferred on day 3, expressed sHLA-G above the geometric mean (sHLA-G+) 46 h post-ICSI, there was a marked improvement in both pregnancy (PR) and implantation (IR) rates. METHODS: The media surrounding individual embryos derived from ICSI performed on oocytes from 482 women < or =43 years of age were tested for sHLA-G expression by specific ELISA. RESULTS: We report here prospective results showing improved IVF results following the transfer of 'good quality' embryos (7-9 cells with <20% fragmentation) by preferentially including at least one sHLA-G+ embryos. PR and IR for women < or =38 years were 63% and 32% when one transferred embryo was sHLA-G+, and 69% and 36% when at least two embryos were sHLA-G+. When none of the embryos transferred was sHLA-G+, PR and IR were 25% and 13%, respectively. Comparable PR and IR for women 39-43 years were 29% and 11% when none of the transferred embryos were sHLA-G+; 38% and 15% when at least one sHLA-G+ embryo was transferred; and 61% and 26% when at least two 2 sHLA-G+ embryos were transferred. The data were stratified by patient age. CONCLUSIONS: PR and IR increased with the addition of each sHLA-G+ embryo, regardless of age. While there are significant barriers to routine embryo sHLA-G testing, we believe that if implemented, this would provide a mechanism for optimizing IVF PR while minimizing the risk of multiple pregnancies.

The Graduated Embryo Score (GES) predicts blastocyst formation and pregnancy rate from cleavage-stage embryos.

BACKGROUND: Embryo morphology and cleavage rates alone do not consistently identify embryos with high implantation potential following IVF. Blastocyst transfer has been reported to improve success rates by identifying potentially superior quality embryos. Algorithms for predicting IVF outcomes based on the presence of early developmental milestones have been proposed. Here we introduce the Graduated Embryo Score (GES). METHODS: Nucleolar alignment along the pronuclear axis, regular cleavage and degree of fragmentation at the first cell division, and cell number and morphology on day 3 were weighted to create a possible GES of 100 for each of 1245 fertilized embryos derived from 109 patients aged <40 years. The GES was correlated with IVF outcome. RESULTS: Of 983 embryos for extended culture, 349 (36%) developed to blastocyst and 180 (18%) were good quality (grade I-II). When ranked by cell number and morphology alone, 34% of embryos with > or =7 cells and <20% fragmentation formed good quality blastocysts. Using GES, embryos scoring 90-100 had 64% blastocyst formation compared with 31% scoring 70-85 and with 11% scoring 30-65. Embryos scoring 70-100 had 44% blastocyst development compared with 9% scoring 0-65. Fifty-six patients (51%) conceived on-going gestations from 294 transferred embryos. In patients with at least one transferred embryo scoring > or =70, the pregnancy rate was 59% compared with 34% if all embryos scored <70. The overall implantation rate was 28%. Among embryos scoring 70-100, an implantation rate of 39% was seen, compared with 24% among embryos scoring 0-65. CONCLUSIONS: Predicting which cleaved embryos will form blastocysts could permit the high success rates associated with blastocyst transfer to be achieved from day 3 embryo transfer.

Blastocyst-ET and monozygotic twinning.

PURPOSE: To examine the rate of monozygotic twinning associated with blastocyst transfer using commercially available, cell-free culture systems with unmanipulated blastocysts. METHODS: A retrospective analysis was conducted in multiple private and academic infertility centers throughout the United States, of 199 pregnant patients following in vitro fertilization (IVF) blastocyst embryo transfer (ET). Human embryos obtained through standard IVF stimulation protocols were cultured in commercially available, cell-free media systems and transferred as blastocysts. The main outcome measure was the rate of monozygotic twinning. RESULTS: A total of 199 blastocyst-ET pregnancies were achieved during the study period at the fertility centers examined. Monozygotic twinning was noted in 10/199 (5%) of these pregnancies. All were monochorionic diamnionic. CONCLUSIONS: Monozygotic twinning previously has been reported following IVF, especially in relation to assisted hatching. While blastocyst transfer has been available for many years using coculture, there have been no published multicenter reports of monozygotic twinning associated with unmanipulated blastocysts. In a multicenter analysis, a definite increase in monozygotic twinning was seen following blastocyst-ET. We believe this phenomenon is real and that this information should be considered when counseling patients for treatment.

Antibodies to phosphatidylethanolamine and phosphatidylserine are associated with increased natural killer cell activity in non-male factor infertility patients.

Antiphospholipid antibodies (APA) have been identified in patients with recurrent pregnancy loss and IVF failure. Of these, antiphosphatidylethanolamine (aPE) and antiphosphatidylserine (aPS) may have special significance. A link between increased natural killer cell activity (NKa+) and trophoblast cell apoptosis has also been reported. This study was undertaken to determine how the APA profile was associated with peripheral NK cell activity. We evaluated 197 female IVF candidates for APA and NKa. Eighty-nine patients (45%) were APA+ and of these, 51 (57%) were aPE/aPS+. Fifty-four patients (27%) had increased NK cell activity. Some 51% of APA+ and 78% of aPE/aPS+ patients had increased NK cell activity compared with 8% and 13% when APA and aPE/aPS tested negative respectively (P: < 0.0001). Non-male factor infertility patients were APA+ and NKa+ in 57% and 34% of cases respectively, compared with 19% and 13% if a pure male factor was present. Some 88% of aPE/aPS+, non-male factor patients had increased NK cell activity, compared with 12% who tested aPE/aPS negative (P: < 0.0001) and 25% of aPE/aPS+, isolated male factor patients (P: < 0.0001). These findings establish a direct relationship between APA (specifically aPE/aPS) and increased peripheral NK cell activity among non-male factor infertility patients. It is possible that APA do not directly cause reproductive failure but rather function as markers or intermediaries for an underlying, abnormal activation of cellular immunity.

Subcutaneous drain vs. suture in obese women undergoing cesarean delivery. A prospective, randomized trial.

OBJECTIVE: To determine if subcutaneous drain or closure of the subcutaneous layer decreases the incidence of wound complications in obese women undergoing cesarean delivery. STUDY DESIGN: Seventy-six obese women undergoing cesarean delivery and with at least 2 cm of subcutaneous fat were randomized to one of three groups: group 1 had suture closure of the subcutaneous tissue, group 2 had placement of a subcutaneous closed suction drain, and group 3 had neither suture closure nor drainage. RESULTS: Wound separation occurred in 12 (15.8%), seroma in 5 (6.6%) and infection in 3 (4%). There were no reports of wound hematoma. The overall incidence of any wound complication (infection, separation, seroma, hematoma) was higher in obese women who received neither subcutaneous suture nor drain as compared to obese women who received either subcutaneous suture closure or subcutaneous drain. The incidence of major wound complications (infection or separation) was also higher in obese women who received neither subcutaneous suture or drain compared to obese women who received either subcutaneous suture closure or subcutaneous drain. CONCLUSION: The use of closed suction drainage in the subcutaneous space may reduce the incidence of postoperative wound complications in obese women who have at least 2 cm of subcutaneous fat and undergo cesarean delivery.

Vaginal sildenafil (Viagra): a preliminary report of a novel method to improve uterine artery blood flow and endometrial development in patients undergoing IVF.

Endometrial growth is thought to depend on uterine artery blood flow and the importance of endometrial development on in-vitro fertilization (IVF) outcome has been previously reported. Nitric oxide (NO) relaxes vascular smooth muscle through a cGMP-mediated pathway and NO synthase isoforms have been identified in the uterus. Sildenafil citrate (Viagra), a type 5-specific phosphodiesterase inhibitor, augments the vasodilatory effects of NO by preventing the degradation of cGMP. In this preliminary report we describe the use of vaginal sildenafil to improve uterine artery blood flow and sonographic endometrial appearance in four patients with prior failed assisted reproductive cycles due to poor endometrial response. The uterine artery pulsatility index (PI) was measured in a mock cycle after pituitary down-regulation with Lupron. The PI was decreased after 7 days of sildenafil (indicating increased blood flow) and returned to baseline following treatment with placebo. The combination of sildenafil and oestradiol valerate improved blood flow and endometrial thickness in all patients. These findings were reproduced in an ensuing gonadotrophin-stimulated cycle. Three of the four patients conceived. Although greater numbers of patients and randomized evaluation are needed to validate this treatment, vaginal sildenafil may be effective for improving uterine artery blood flow and endometrial development in IVF patients with prior poor endometrial response.

Comparison of blastocyst transfer with day 3 embryo transfer in similar patient populations.

OBJECTIVE: To compare implantation and pregnancy rates (PRs) achieved with blastocyst transfer (BT) and day 3 ET in similar patient populations. DESIGN: Retrospective analysis. SETTING: Academic infertility center. PATIENT(S): One hundred consecutive patients <40 years undergoing IVF, each with more than three eight-cell embryos on day 3. INTERVENTION(S): Patients used their own eggs for IVF or IVF and intracytoplasmic sperm injection. Embryos were cultured in P1 medium (Irvine Scientific, Santa Ana, CA) until day 3, when they were either transferred or, in the case of embryos for BT, incubated in Blastocyst Medium (Irvine Scientific), followed by transferring on day 5. MAIN OUTCOME MEASURE(S): Implantation and PRs. RESULT(S): There were no statistically significant differences in patient age, FSH level, or number of oocytes or zygotes. The BT group had fewer embryos transferred (mean, 2.4) compared with the day 3-ET group (mean, 4.6). The viable PR (cardiac activity at 6-7 weeks was considered indicative of a viable pregnancy) was higher with BT (68%, 34/50) than with day 3 ET (46%, 23/50). The implantation rate was increased with BT (47%, 56 sacs/120 embryos) compared with day 3 ET (20%, 46 sacs/231 embryos). CONCLUSION(S): The BT group in our study had higher implantation and PRs compared with the day 3-ET group. Better embryo selection, improved embryo-uterine synchrony, and decreased cervical mucus on day 5 may have accounted for the enhanced outcome. Our data support the use of BT to limit the number of embryos transferred while improving PRs.

Two-blastocyst transfer has similar pregnancy rates and a decreased multiple gestation rate compared with three-blastocyst transfer.

OBJECTIVE: To examine the effect of the number of blastocysts transferred on pregnancy and multiple gestation rates. DESIGN: Retrospective study. SETTING: Academic infertility center. PATIENT(S): Patients < 40 years undergoing IVF, with FSH levels of < 15 mIU/mL and more than three eight-cell embryos. INTERVENTION(S): Embryos were cultured in P1 until day 3 and then transferred to blastocyst medium. A maximum of three blastocysts were transferred. MAIN OUTCOME MEASURE(S): Pregnancy, multiple gestation, and implantation rates. RESULT(S): All 55 patients developed blastocysts and underwent ET. Twenty-four patients had three embryos transferred and 29 patients had two embryos transferred. Two patients had only one embryo each for transfer. There was no difference in the viable pregnancy rate between the two-blastocyst transfer and three-blastocyst transfer groups (62% vs. 58%). In the two-blastocyst transfer group, 39% of pregnancies were multiple gestations (all twin gestations), compared with 79% of pregnancies in the three-blastocyst transfer group (50% twin gestations, 29% triplet gestations). The implantation rate was 47% in both groups. CONCLUSION(S): A commercially available, sequential culture system is highly effective for producing viable blastocysts. Two-blastocyst transfer eliminated the risk of triplets while maintaining the same high success rates seen with three-blastocyst ET.

Aspiration of a single dominant follicle leads to improved cohort development and pregnancy in a patient with poor response to in vitro fertilization treatment.

OBJECTIVE: To report improved follicular cohort development and a healthy ongoing pregnancy after midcycle aspiration of a single dominant ovarian follicle in a patient with poor response to IVF treatment. DESIGN: Case report. SETTING: University-based infertility center. PATIENT(S): A 39-year-old woman (gravida 1, para 0) with a borderline FSH level and four previous unsuccessful IVF attempts. INTERVENTION(S): A single 27-mm follicular cyst was aspirated after 13 days of treatment, while controlled ovarian hyperstimulation was continued. MAIN OUTCOME MEASURE(S): Number of follicles developed, number of oocytes retrieved, development of a clinical pregnancy. RESULT(S): In previous attempts, the patient had no more than two dominant follicles and a maximum of three oocytes retrieved. After midcycle aspiration of the single lead follicle, a new cohort of seven follicles developed and seven oocytes were recovered. Six embryos were replaced by tubal ET and an ongoing singleton gestation resulted. CONCLUSION(S): Midcycle aspiration of a single lead follicle in a patient with poor response to IVF treatment allowed the development of a larger secondary cohort of follicles during the same cycle and ultimately led to a viable pregnancy. This intervention may have future implications for the treatment of poor responders.

Sibling embryo blastocyst development correlates with the in vitro fertilization day 3 embryo transfer pregnancy rate in patients under age 40.

OBJECTIVE: To examine the IVF day 3-ET pregnancy rate in patients under 40 with sibling embryo blastocyst development, compared with similar patients without blastocyst formation. DESIGN: Retrospective analysis. SETTING: Academic infertility center. PATIENT(S): One hundred twenty-five IVF day 3-ET patients under 40 with sibling embryos for extended culture. INTERVENTION(S): Extended culture of nontransferred sibling embryos for blastocyst development. MAIN OUTCOME MEASURE(S): Pregnancy and multiple gestation rates, number of oocytes, embryos formed, and embryos transferred. RESULT(S): Thirty-eight percent of patients became pregnant. Forty-eight percent of patients had sibling embryos develop to blastocyst. The blastocyst group had more oocytes retrieved (17.4+/-6.6 versus 14.4+/-5.6), more embryos formed (11.2+/-4.2 versus 8.8+/-3.2), and a higher clinical pregnancy rate (60% versus 18%) than the group without blastocyst development. CONCLUSION(S): Blastocyst transfer has been shown to improve implantation rates and reduce the risk of multiple gestations from assisted reproductive technology. Sibling embryo blastocyst development may reflect superior embryo quality, as manifested by increased IVF-ET pregnancy rates. In addition to predicting pregnancy in the current cycle, sibling embryo blastocyst development may provide information about the potential for fresh blastocyst transfer in subsequent cycles and help to identify patients at risk for multiple gestations.

Medical management of interstitial ectopic pregnancy: a case report and literature review.

Recent reports describe successful treatment of interstitial ectopic pregnancies using methotrexate. While the number of reported cases is increasing, no consensus exists regarding the management of this complication of pregnancy. We present the successful use of combined systemic and direct intrasac injection of methotrexate for an interstitial pregnancy with the highest yet reported initial beta-human chorionic gonadotrophin concentration (102,000 mIU/ml). We also describe the use of Doppler ultrasound for monitoring treatment progression. Through a review of the current literature, we propose to facilitate management decisions and increase outcome success by summarizing previously reported treatment regimens and by describing enhanced parameters for patient selection and monitoring.

Enhancement of motility and acrosome reaction in human spermatozoa: differential activation by type-specific phosphodiesterase inhibitors.

Inhibition of sperm phosphodiesterase (PDE) has been shown to increase cAMP concentrations and stimulate motility and the acrosome reaction. While several PDE genes exist in mammals, little is known about the physiological role of PDE forms expressed in human spermatozoa. Using type-selective inhibitors, we identified two of the PDE forms expressed in human spermatozoa and studied their involvement in sperm function. Selective inhibitors of calcium-calmodulin-regulated PDE1 (8-methoxy-isobutyl-methylxanthine) and cAMP-specific PDE4 (RS-25344, Rolipram) were used to study PDE forms in human sperm extracts. 8-MeIBMX and Rolipram/RS-25344 inhibited sperm PDE activity by 35-40 and 25-30% respectively. Subcellular fractionation of the sperm homogenate suggests these pharmacologically distinct forms may be located in separate cellular regions. To evaluate the functional significance of different PDE forms, the effect of type-specific PDE inhibition on sperm motility and the acrosome reaction was examined. PDE4 inhibitors enhanced sperm motility over controls without affecting the acrosome reaction, while PDE1 inhibitors selectively stimulated the acrosome reaction. These data indicate at least two distinct PDE types exist in human spermatozoa. Our findings also support the hypothesis that PDE subtypes affect sperm function by regulating separate pools of cAMP and may ultimately offer novel treatments to infertile couples with abnormal semen parameters.

Vaginal ultrasound probe cover leakage: implications for patient care.

OBJECTIVE: To assess the risk of probe contamination following transvaginal ultrasonography. DESIGN: Prospective cohort study. SETTING: University Infertility Center. PATIENT(S): Women undergoing transvaginal ultrasonography. INTERVENTION(S): One physician obtained 840 consecutive transvaginal ultrasonograms over nine months. Latex condoms were used to cover the probe. Following examination, the condoms were removed and the probe was wiped with a germicidal disposable cloth and left to air dry for 5 minutes. Condoms were filled with water and examined for leaks. MAIN OUTCOME MEASURE(S): Number of perforations and distance from condom tip. RESULT(S): Seventeen (2%) of 840 condoms leaked. The mean distance from the tip to the point of leakage was 10.6 cm +/- 2.8 (mean +/- SD; range, 7-14). Sixty-five percent of the leaks were < or = 10 cm from the tip. In several instances, two leaking condoms were found within a few examinations of each other. No visual contamination of the probe was noted. CONCLUSION(S): Although only 2% of condoms leaked, 65% were at distances that could have led to probe soiling intravaginally. While no body fluids were grossly visible, microscopic contamination was still possible. Since perforations were noted in close, and even consecutive scans, this study underscores the need for routine probe disinfection between examinations.

Treatment of renal allograft acute rejection with methylprednisolone: effect of fixed dose versus dose per body mass index.

Considerable interpatient variability in steroid pharmacokinetics has been observed in renal transplant recipients. The purpose of this retrospective study is to evaluate the relationship between the dose of methylprednisolone (MP) used to treat acute rejection (AR) after renal transplantation and the response to treatment. 117 first AR episodes from 408 renal transplants were reviewed. The dose of MP used to treat AR was < 45 mg/kg/m2 in 60 patients and > and = 45 mg/kg/m2 in 57 patients. The correlation between fixed dose ( < 1.25 vs. > and = 1.25 g) and dose based on BMI was evaluated by simple linear regression analysis (r2 = 0.78, p < 0.0005). Response to treatment was as follows: MP successful (Group 1, n = 80); MP failed, OKT3 successful (Group 2, n = 17); MP and OKT3 failed (Group 3, n = 3) and MP failed, no further treatment (n = 17). No relationship was observed between the dose of MP, whether fixed or based on BMI, and (1) response to treatment of the first AR, (2) incidence of a second AR and (3) response to subsequent treatment with OKT3. Actuarial graft survival was higher in Group 1 compared to Group 2 (p < 0.0005), lower in Black recipients (p = 0.02) and higher when > and = 45 mg/kg/m2 of MP was used to treat AR (p = 0.06). In conclusion, no relationship between the dose of MP, whether fixed or based on BMI, and the response to treatment of AR was observed. MP dosage based on BMI may be a reasonable alternative to a fixed-dose regimen with the advantage of limiting steroid exposure and the consequent side-effects.

Erythromycin-induced clozapine toxic reaction.

Clozapine, used in the treatment of patients with schizophrenia resistant to other neuroleptic medication, is metabolized by the hepatic microsomal system to demethyl-clozapine and clozapine-N-oxide. Changes in clozapine serum concentrations have been documented after initiation of therapy with medications known to induce or inhibit liver microsomal enzymes. These interactions are of clinical importance when diminished efficacy or increased toxic effects of clozapine therapy occur. A 34-year-old schizophrenic man had increased clozapine serum concentrations, leukocytosis, and adverse effects as a result of concomitant erythromycin therapy given for suspected lower respiratory tract infection. Symptoms included somnolence, difficulty in coordination and ambulation, slurred speech, disorientation, and incontinence. The symptoms resolved after treatment with clozapine and erythromycin were discontinued, and treatment with clozapine was gradually resumed.

The self in psychotherapy.

This paper presents Kohut's position regarding the use of introspection and empathy as the predominant tools of observation for any approach to be called psychological. This translates into the need to maintain a consistent focus on the patient's self experience, and for interpretations to be "experience near." The concept of selfobject and the specific selfobject transferences are reviewed, and the model of Muslin and Val is used to differentiate supportive psychotherapy, psychoanalytic psychotherapy and psychoanalysis. A case illustration is presented demonstrating psychoanalytic psychotherapy where the therapeutic work focused on the patient's relationship outside the treatment, the "extra-transference object." The indications for and therapeutic value of this approach are discussed.

The renal hemodynamic response to endothelin in chronic cyclosporine-treated dogs.

Use of the immunosuppressive agent cyclosporine A (CyA) is limited by its associated nephrotoxicity, characterized by an increase in renal vascular resistance (RVR) and reductions in renal blood flow (RBF) and glomerular filtration rate (GFR). The vascular endothelium produces vasoactive substances including endothelium derived relaxation factor (EDRF) and endothelin (ET), which modulate vascular tone. Since CyA has been shown to damage the endothelium, we examined the renal hemodynamic response to intrarenal ET infusion (4 micrograms./kg./minute) in chronic cyclosporine-treated dogs. Prior to ET infusion, CyA-treated dogs had a lower RBF and a greater RVR than normal dogs. In normal dogs, after ET infusion RVR increased from 30.24 +/- 0.64 to 44.60 +/- 1.66 mmHg./ml./minute (p < 0.001), RBF decreased from 4.26 +/- 0.28 to 2.90 +/- 0.30 ml./min./g. (p < 0.001) and GFR decreased from 50.20 +/- 5.90 to 36.50 +/- 7.90 ml. per minute (p < 0.001). In contrast, there was no change in RBF, GFR and RVR after intrarenal ET infusion in CyA-treated dogs. Prior to ET infusion, arterial plasma ET concentration was 5.0 +/- 1.1 pg./ml. in CyA-treated dogs, similar to 7.5 +/- 1.4 pg./ml. in normal dogs, and was not significantly altered in either group after intrarenal ET infusion. We conclude that ET may not contribute to the increased RVR in chronic cyclosporine nephrotoxicity, and suggest a vascular toxicity of CyA, rendering renal vessels unresponsive to the vasoconstrictive effect of ET.

Circadian rhythm dependent kanamycin-induced hearing loss in rodents assessed by auditory brainstem responses.

An antimicrobial agent, kanamycin, has been shown to produce as an untoward effect, ototoxicity. The purpose of this study was to investigate differential effects of kanamycin ototoxicity as a function of Rx timing with regard to circadian rhythms. Four groups of comparable weight Sprague-Dawley rats received a daily subcutaneous dosage of 225 mg/kg kanamycin sulfate with each receiving the antibiotic at a different time: 8 AM (8A), 2 PM (2P), 8 PM (8P), and 2 AM (2A). The rats were housed in separate cages, in a room on a light-dark (12:12) illumination cycle with light between 6 AM and 6 PM. Hearing loss was assessed with the auditory brainstem response (ABR) using pure tone stimuli at 8, 16, 24, and 32 kHz. ABR measures were obtained before dosing began and 2, 4, and 6 weeks after the initial dosing. Kanamycin produced a hearing loss which reflected the total dosage given to each group. Significant differences in physiologic thresholds were observed for both timing of the daily dosage (p less than 0.05), and the 2, 4 and 6 week testings (p less than 0.001). After 2 weeks, the 8A group showed an average hearing loss of 11.5 dB at 32 kHz, with the other timed treatment groups exhibiting minimal effects (3.0-6.5 dB). For the 8A group at this frequency, the loss progressed at 4 (19.5 dB) and 6 (22.5 dB) weeks. The 2P group after 4 weeks exhibited similar losses as the 8A group for this frequency, with the loss at 6 weeks being even greater (34.0 dB). The 8P and 2A groups exhibited only slight losses over all frequencies.(ABSTRACT TRUNCATED AT 250 WORDS)