Noninvasive ultrasonic carotid angiography: prospective validation by contrast arteriography

A technique for the beat-by-beat measurement of stroke volume is described. Aortic blood velocity signals are obtained from a catheter-mounted electromagnetic velocity transducer and analysed by a purpose-built analog computer. The stroke volume is computed by integration of each period of systolic forward flow using the velocity signal as its sole input. Automatic compensation of flowmeter drift is incorporated and inappropriate triggering of integration by diastolic artefact is prevented by applying both amplitude and duration criteria for the recognition of systolic forward flow. Early diastolic reverse flow is excluded from integration. The cardiac output, mean aortic flow per beat, and interbeat interval are also computed from the velocity signal. With aortic pressure as an additional input signal the mean arterial pressure per beat and systemic vascular resistance can be computed. The computer outputs are calibrated by a manual method. Preliminary studies comparing values for the cardiac output measured by this system and the direct Fick technique have indicated an excellent correlation between the two methods.     

The effect of cryosurgical ablation of the prostate on erectile function

OBJECTIVE: To investigate the incidence and identify the possible cause of erectile dysfunction after cryoablation of the prostate. PATIENTS AND METHODS: Erectile function was examined prospectively in 15 sexually active men (aged 59-72 years) who underwent cryoablation of the prostate for clinically localized prostate cancer. Erectile function was assessed before and 6 months after treatment; after intracavernosal injection with 10 micrograms of prostaglandin E1 (PGE1), the degree and duration of erection, the size of the cavernosal arteries, the penile arterial blood flow velocity, and the time to achieve peak flow were evaluated using high-resolution ultrasonography and colour pulsed-Doppler spectral analysis. RESULTS: Post-operatively, all patients initially reported an inability to achieve an erection sufficient for vaginal intercourse. At 6 months' follow-up, erectile dysfunction persisted in nine, with minimal or no response to the intracavernosal PGE1 injections, there was a significant decrease in the peak velocity of blood flow within cavernosal arteries and a significant increase in the time to achieve peak arterial flow. CONCLUSION: Although many factors may contribute to erectile dysfunction after cryoablation of the prostate, vascular injury plays a major role.     

Visual laser ablation of the prostate for patients with acute urinary retention

Examination of the long-term relation of a single fibrinogen determination to initial and recurrent atherosclerotic cardiovascular events over 20 years of follow-up revealed a powerful and comparably independent impact on initial events in both sexes but an influence on recurrent events only in men.     

In vitro quantification of radiofrequency ablation lesion size using intracardiac echocardiography in dogs

It was shown that L-arginine (up to 0.5 mM) competitively inhibits the NADPH-diaphorase activity in drosophila melanogaster. The value of inhibition constant is equal to 103 microM. In the presence of higher concentration of L-arginine total NADPH-diaphorase activity includes not only the L-arginine inhibited component, but also the non-inhibited one.     

Catheter-free endoscopic laser ablation of the prostate using a 1-size prostatic stent

PURPOSE: Endoscopic laser ablation of the prostate is a safe alternative to transurethral prostatic resection. Recognized disadvantages include prolonged catheterization, postoperative discomfort and delayed symptomatic improvement. We assessed the role of a 1-size temporary prostatic stent in men undergoing endoscopic laser ablation of the prostate. MATERIALS AND METHODS: A total of 55 men a mean of 73 years old with outflow obstruction, including 9 who presented in urinary retention, underwent endoscopic laser ablation of the prostate and temporary stenting. Urinary flow rate, residual urine volume, symptom score and prostate specific antigen were measured preoperatively, and 6 weeks (with the stent in situ), 3 months (after stent removal) and 12 months postoperatively. Duration of hospital stay and complications were also recorded. RESULTS: Of the 55 men 37 (67%) voided immediately with the stent in situ, including 7 of the 9 in retention. At 6 weeks with the stent in place mean maximum urine flow was 17.3 ml. per second (preoperatively 8.7). Dysuria was reported by 3 patients. Stent related complications were rare. One stent migrated early, resulting in urinary retention, while 2 that migrated late were asymptomatic. No patient had acute urinary retention after stent removal. Maximum urinary flow rate measured at 6 weeks with the stent in situ was similar to that 1 year after endoscopic laser ablation of the prostate. CONCLUSIONS: The use of a 1-size, inexpensive plastic prostatic stent enabled catheter-free endoscopic laser ablation of the prostate in 67% of our patients. Early improvements in the urinary flow rate and a lower incidence of dysuria were additional benefits. The result of endoscopic laser ablation of the prostate at 1 year was comparable to that of transurethral prostatic resection.     

Comparison of three methods for relief of pain after ear canal ablation in dogs

This study compared three methods of pain relief in dogs that had total ear canal ablation with lateral bulla osteotomy. The hypothesis was that systemic opioids with preoperative local nerve blocks would provide superior pain relief. Thirty-one dogs with chronic otitis externa were included in the study. Dogs were randomly assigned to one of three protocols: systemic opioids alone (10 dogs, group 1), systemic opioids with bupivacaine splash block (11 dogs, group 2), and systemic opioids with preoperative local bupivacaine nerve blocks (10 dogs, group 3). Twenty-one dogs had bilateral ear ablation and 10 had unilateral ablation. Pain was assessed preoperatively, at extubation, 2 hours postextubation, and 1 day postoperatively by a single observer blinded to the analgesic protocol used. Pain scores were not significantly different within or between groups, nor did unilateral versus bilateral ablation have a significant effect on the score. Mean scores were less than 3 (scale 1 to 5) for all groups at all observation times. Rough recoveries were noted in 30% of group 1 dogs, 0% of group 2, and 20% of group 3 dogs. Ninety-four percent of dogs were moderately to heavily sedated at extubation. Sixty percent of group 3 dogs remained moderately to heavily sedated 2 hours postextubation. Rectal temperature, pulse rate, respiratory rate, and postoperative change in serum cortisol levels were not significantly different between groups. Postoperative increase in blood glucose was significantly higher in groups 1 and 3 compared with preoperative levels. Twenty-three percent of the dogs required additional analgesia or tranquilization after surgery, as determined by the anesthetist; 1 dog in group 1, 2 in group 2, and 4 in group 3. Each of the three analgesic protocols provided similar pain relief in dogs undergoing total ear canal ablation.     

Histological presence of viable prostatic glands on routine biopsy following cryosurgical ablation of the prostate

PURPOSE: Cryosurgical ablation of the prostate has recently received much attention as a therapeutic alternative for the treatment of localized prostatic adenocarcinoma. Biopsies after treatment reveal a variety of dysplastic changes as well as unaltered prostatic glandular epithelial elements. Prostate specific antigen (PSA) remains undetectable in the majority of men. However, in some PSA increases without demonstrable local recurrence. MATERIALS AND METHODS: A total of 383 patients underwent 447 procedures between June 1990 and January 1994. Of 358 biopsies performed at our institution, 317 (2,075 cores) were available for review. Each core was examined for unaltered prostatic glandular epithelial elements and then scored for the percentage of epithelial glandular involvement according to a scale of: 0-no, 0.5-less than 10%, 1-10 to 25%, 2-25 to 50%, 3-50 to 75% and 4-76 to 100% unaltered prostatic glandular epithelial elements. RESULTS: Of 317 biopsies 158 (49.8%) contained no unaltered prostatic glandular epithelial elements, while 185 (58.3%) and 206 (65%) had 1 core containing 10% and 10 to 25%, respectively, of such elements. Of 262 cases (82.6%) with a mean of 10% unaltered prostatic glandular epithelial elements per core 22 (8.4%) were positive for residual carcinoma. Among 55 cases with more normal epithelium per core 24 (43.6%) were positive for residual carcinoma. Patients with a positive biopsy had a median PSA of 2.02 ng./ml. (average gland/core score 0.54). Median PSA for men with negative biopsies was 0.2 ng./ml. (gland/core score 0.124). CONCLUSIONS: Cryosurgical ablation of the prostate has the ability to ablate prostatic tissue completely, thus rendering it free of glandular elements as determined by biopsy. Increasing PSA can indicate residual glandular elements. Increases in unaltered prostatic glandular epithelial elements with time are not paralleled by increased rates of local disease recurrence. undetectable serum PSA has a low risk of residual unaltered prostatic glandular epithelial elements and localized carcinoma. Results as measured by unaltered prostatic glandular epithelial elements and PSA improve with the surgical experience.     

Transurethral needle ablation of the prostate: a minimally invasive treatment for symptomatic benign prostatic hyperplasia

Transurethral needle ablation of the prostate, a relatively new minimally invasive treatment modality for patients with bladder outlet obstruction attributable to an enlarged prostate gland, has undergone extensive evaluation by numerous investigators worldwide. The results to date indicate that needle ablation is safe and effective for relieving symptoms in patients with benign prostatic hyperplasia, and the effect has been demonstrated to be durable for at least 2 years. Nevertheless, additional investigations with longer follow-up data are needed to address the important issues of extended durability (5 to 10 years) and biophysiologic mechanism of action. Comparisons between transurethral needle ablation of the prostate and transurethral resection of the prostate (TURP) have revealed that the subjective and objective measures of response are comparable, although TURP has consistently displayed a slight advantage over needle ablation for most variables analyzed, except quality of life score. The advantages of needle ablation over TURP are (1) performance in the office as an outpatient procedure, (2) no need for general or spinal anesthesia, (3) rapid recovery, (4) minimal side effects, and (5) one-time intervention. The following disadvantages exist with needle ablation: (1) it may not be indicated or effective in patients with large prostate glands (75 g or more); (2) no prostate tissue is available for histologic evaluation; and (3) no long-term efficacy or re-treatment rate data have been published. Overall, the available information indicates that transurethral needle ablation is a viable minimally invasive treatment that may be applicable in men with moderate to severe bladder outlet obstruction as a result of an enlarged prostate gland.     

Transrectal ultrasonic planimetry of the prostate in relation to age and lower urinary tract symptoms among elderly men in Japan

We investigated the responses to insect prey (dead houseflies) in 24 "derivative groups" of workers of the ant Formica polyctena created by taking sets of 25 workers out of nine larger "initial groups" kept in laboratory without queens and brood during the preceding five months. In the derivative groups the ants ceased to retrieve flies to their nests after a period ranging from few days to several weeks. The duration of that period did not depend on the present size of the derivative group (decreasing as a result of worker mortality), but was positively correlated with the estimated size of the initial group of the tested ants. The readiness to display venom spraying was higher in smaller derivative groups. These data demonstrate that responses of F. polyctena to insect prey are strongly influenced both by the present and the past size of their group.     

Holmium laser resection of the prostate versus neodymium:yttrium-aluminum-garnet visual laser ablation of the prostate: a randomized prospective comparison of two techniques for laser prostatectomy

Prospective studies were conducted at used-tire sites in Illinois during 1994-1995 in an effort to isolate arboviruses from mosquitoes, particularly Aedes albopictus (Skuse) and Aedes triseriatus (Say). Three isolates of Potosi virus were obtained from Ae. albopictus collected at a waste tire site in Jasper County during 1994 and 1995. Also, a single isolate of Cache Valley virus was obtained from Ae. albopictus collected at the Jasper County site during 1995. These are the first records of arbovirus isolations from Ae. albopictus in Illinois and the first isolate of Cache Valley virus from this mosquito species. During 1994, two isolates of La Crosse virus were made from Ae. triseriatus collected at a used-tire site in Peoria County in proximity to the residence of a human La Crosse encephalitis case. This is the first evidence in Illinois that indicates increased risk to humans living near used-tire sites, which may serve as foci for production of Ae. triseriatus, the vector of La Crosse virus. Tire removal and improved environmental sanitation at such sites may greatly reduce the abundance of vector mosquitoes, and, therefore, the risk of arbovirus transmission.     

Noninvasive electrodes for electrocochleography in the chinchilla

This study compares noninvasive vs invasive electrodes for electrocochleography in chinchillas. Summating potential (SP) amplitude, action potential (AP) amplitude, and AP threshold, recorded with five types of noninvasive electrodes, were compared with simultaneous bulla recordings. Noninvasive electrodes included a needle electrode over the bulla, gold Tiptrode (Etymotic Research, Elk Grove Village, Ill), Enhancer I (Nicolet Instrument Corp, Madison, Wis), Coats (Lifetech Inc, Austin, Tex) electrode, and a locally constructed tympanic membrane (TM) electrode. Stimuli included 100-microsecond clicks and 6000-Hz tone bursts (with a 1 millisecond rise/fall time and a 5 millisecond plateau). Stimuli were initially presented at 110 dB peak equivalent sound pressure level for the clicks and 100 dB peak equivalent sound pressure level for the tone bursts. Intensity was then decreased in 10-dB decrements until no replicable AP activity was observed. The TM damping for the TM electrode was measured with 0.5, 1, 2, 4, and 6 kHz and click stimuli. The AP was clear and replicable for all electrodes used in the study, although the amplitude was substantially less for the noninvasive electrodes as opposed to the invasive electrode. The invasive electrode provided the largest amplitude SP recording, but SP could generally be clearly recorded with the needle electrode, Enhancer I, and the Coats electrode. The TM electrode and gold Tiptrode provided SP recordings less consistently. The AP threshold could be recorded with all the electrodes in the study and was generally within 10 dB of threshold recorded invasively. Electrode variables, including ease of electrode placement and potential injury, were examined. The Tiptrode and Enhancer I electrodes posed relatively few problems during placement.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of a new non-steroidal 5 alpha-reductase inhibitor, FK143, on the prostate gland in beagle dogs

In most metazoans, the glutathione S-transferases (GST) are encoded by gene families, and are used to detoxify xenobiotics. We describe the structure of genomic loci coding for the GSTs in the housefly that have been implicated, by both genetic and biochemical means, in mediating insecticide resistance. In earlier work, we showed that one of the theta-class enzymes, MdGST-3, is overproduced in resistant flies and degrades certain insecticides. We used a fragment from a cDNA clone of MdGST-3 as a probe to screen a housefly genomic DNA bank in phage lambda. This probe detected multiple gst loci. Genes for GSTs were found in five different, nonoverlapping lambda clones, three of which carry multiple, closely linked gsts. Multiple genes for both MdGST-3 and MdGST-4 were found; some of which have introns in their 5' untranslated regions. In adults, the only MdGST-3 enzymes that are expressed are encoded by the intron-free genes. A new theta-class GST (called MdGST-5) was also discovered. Fusion genes comprising 5' MdGST-3 sequences and either MdGST-4 or MdGST-5 sequences in their 3' halves were encountered at three separate loci. The genes described here are found in both the ancestral sensitive strain and the insecticide-resistant strains.     

Mediastinoscopic subtotal removal of mediastinal cysts

We report a case of relapsing polychondritis with focal sensorimotor seizures, aseptic meningitis, and migratory leptomeningeal enhancement on contrast MRI. These abnormalities on imaging studies correlated accurately with laterality of the patient's seizures, facilitating early aggressive management of his neurologic symptoms.     

Apoptosis and other mechanisms in androgen ablation treatment and androgen independent progression of prostate cancer: a review

Patients with advanced prostate cancer commonly present with disseminated disease. For these patients, androgen ablation is a first-line treatment. This mode of therapy usually has an initially palliative effect on tumor-related symptoms and slows growth, although virtually all tumors eventually relapse to an androgen-independent, more aggressively growing phenotype. However, surprisingly little is known about the actions mediating the initial palliative effect as well as the initiation of androgen-independent tumor growth. In this review, some current concepts on mechanisms of androgen ablation treatment and androgen-independent progression of prostate cancer is highlighted. Special attention is given to the involvement of apoptosis in these processes.