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Biomedical subjects

R L Goode

Publications and source records attributed to R L Goode.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effect of increased inner ear pressure on middle ear mechanics.

Velocity of malleus, umbo, and stapes footplate in response to stepwise increases up to +400 mm H2O in hydrostatic pressure of the inner ear was investigated in 10 fresh human temporal bones by using a laser Doppler interferometer. The sound-pressure input was 114 dB SPL, and the frequency range was 0.4 to 5.0 kHz. Static displacement of these sites was also measured by a video measuring system. When the inner ear pressure was increased, the malleus and stapes moved outward. Amplitude of umbo velocity decreased below 1.0 kHz with a slight increase around 2.0 kHz, whereas stapes velocity decreased at all frequencies with the major effect below 1.0 kHz. The phase angle of malleus umbo velocity advanced markedly in response to the increased inner ear pressure between 1.0 and 1.4 kHz. Change in the vibration of the umbo was thought to be primarily caused by an increased stiffness of the middle ear conduction system, and that of the stapes was caused by distention of the annular ligament and increased cochlear impedance produced by the increased inner ear pressure. These changes in TM vibration and its phase angle may help detect indirectly an elevation of inner ear pressure.

Aged↗
PubMed1997

Transcalvarial suture fixation for endoscopic brow and forehead lifts.

OBJECTIVE: To evaluate the safety and effectiveness of transcalvarial suture fixation during endoscopic repair of brow ptosis. DESIGN: Case series. SETTINGS: A private ambulatory surgicenter and a Veterans Affairs Hospital. PARTICIPANTS: Fifty patients with brow ptosis with minimum follow-up of 12 months. RESULTS: Patients had improvement in brow position in all cases. There were no adverse effects of performing cortical tunnels and suture fixation. CONCLUSION: Transcalvarial suture fixation can be performed safely with good to excellent results and avoids the need for screw or plate fixation.

Endoscopy↗
PubMed1997

Patient selection in the treatment of glabellar wrinkles with botulinum toxin type A injection.

OBJECTIVES: To determine the dose-response characteristics and side-effects profile of Clostridium botulinum type A exotoxin (Botox) used to treat glabellar wrinkles and develop guidelines for patient selection based on the nature and severity of the treated wrinkles. DESIGN: Prospective, nonrandomized pilot and electromyogram (EMG)-guided studies. SETTING: Two ambulatory care clinics at university hospitals. PARTICIPANTS: For the pilot study, volunteer samples of 23 patients with glabellar wrinkles; for the EMG-guided study, volunteer samples of 57 patients with glabellar wrinkles. INTERVENTIONS: For the pilot study, 23 patients were serially injected with up to 10.0 mouse units (MU) of Botox into each corrugator muscle; for the EMG-guided study, 57 patients were injected under EMG guidance with an initial dose of 10.0 MU of Botox into each corrugator muscle. Eleven patients with persistent corrugator activity were reinjected with 10.0 MU of Botox. MAIN OUTCOME MEASURES: For the pilot study, slide photographs were obtained before and 2 weeks after injection; for the EMG-guided study, slide photographs were obtained before and at 2 weeks and at 2 months after injection. Patients were asked to evaluate results numerically. RESULTS: For the pilot study, injection of up to 10.0 MU of Botox into each corrugator muscle produced a satisfactory improvement in 12 patients; for the EMG-guided study, 43 patients were satisfied with improvement after full abolition of corrugator or accessory lateral brow muscle activity. Women were more likely to achieve satisfactory results than were men (80% [40/50] vs 43% [3/7]; P < or = .03). Improvement was not age related. No significant side effects or complications were observed. CONCLUSIONS: Glabellar wrinkles may be satisfactorily treated with Botox injection into the corrugator supercilii muscles. Improvement is temporary, dose dependent, and may not be seen in some patients even with successful denervation of the treated muscles. Clinicians may begin treatment with a dose of 10.0 MU of Botox into each corrugator muscle, and may select candidates for injection by determining the type of wrinkle to be treated and its spreadability (glabellar spread test).

Adult↗
PubMed1997

Distortion of the auriculocephalic angle following rhytidectomy. Recognition and prevention.

Distortion of ear protrusion after rhytidectomy results in an aesthetically unfavorable appearance. We have seen cases in which the auriculocephalic angle has widened postoperatively, producing a noticeable deformity. Herein, we report 3 cases that resulted in abnormal postsurgical ear protrusion. We also discuss prevention through the use of conchal setback sutures.

Adult↗
PubMed1997

Contemporary management of the aging brow and forehead.

Management of the aging brow and forehead has recently evolved based on available innovative technologies. Likewise, procedure-specific indications have changed based on collective surgical experiences. No longer is the approach based solely on hair pattern or degree of brow ptosis. Patients require varying combinations of brow elevation (prior to blepharoplasty), correction of brow asymmetries, and hairline-preserving forehead elevation. Some may only require excisional or paralytic procedures of the frontalis muscle (horizontal forehead creases), corrugator supercilii muscles (vertical glabellar furrows), and procerus muscle (horizontal glabellar furrows). We present a 3-year experience using a problem-specific approach. This incorporates endoscopic technology, botulinum toxin type A purified neurotoxin complex (Botox, Allergan, Irvine, CA) intramuscular injection, and traditional procedures such as the coronal, pretrichial, midforehead, and direct browlift. Current indications, patient selection, and results are also discussed.

Aging↗
PubMed1997

Acoustic effect of malleus head removal and tensor tympani muscle section on middle ear reconstruction.

In the reconstruction of ears with a missing incus, an incus replacement prosthesis (IRP) is commonly used to connect malleus and stapes. In some cases, it is necessary to resect the malleus head and/or section the tensor tympani muscle (TTM) tendon. The acoustic effects of these maneuvers have not been well studied. We performed experiments in a temporal bone model to measure the effect of these maneuvers on middle ear sound transmission. Measurements of umbo and stapes displacement were made before and after malleus head removal and TTM section plus incus replacement with an IRP. After malleus head removal, there was a peak gain in stapes displacement of 6 dB below 0.5 kHz and 8 dB above 2.5 kHz. TTM section had a similar but lesser effect. A clinical example is described.

Acoustic Stimulation↗
PubMed1997

Serum-free keloid fibroblast cell culture: an in vitro model for the study of aberrant wound healing.

The purpose of this study was to develop an in vitro serum-free keloid fibroblast model. Keloid formation remains a problem for every surgeon. Prior evaluations of fibroblast characteristics in vitro, especially those of growth factor measurement, have been confounded by the presence of serum-containing tissue culture media. The serum itself contains growth factors, yet has been a "necessary evil" to sustain cell growth. The design of this study is laboratory-based and uses keloid fibroblasts obtained from five patients undergoing facial (ear lobule) keloid removal in a university-affiliated clinic. Keloid fibroblasts were established in primary cell culture and then propagated in a serum-free environment. The main outcome measures included sustained keloid fibroblast growth and viability, which was comparable to serum-based models. The keloid fibroblast cell cultures exhibited logarithmic growth, sustained a high cellular viability, maintained a monolayer, and displayed contact inhibition. Demonstrating model consistency, there was no statistically significant difference between the mean cell counts of the five keloid fibroblast cell lines at each experimental time point. The in vitro growth of keloid fibroblasts in a serum-free model has not been done previous to this study. The results of this study indicate that the proliferative characteristics described are comparable to those of serum-based models. The described model will facilitate the evaluation of potential wound healing modulators, and cellular effects and collagen modifications of laser resurfacing techniques, and may serve as a harvest source for contaminant-free fibroblast autoimplants. Perhaps its greatest utility will be in the evaluation of endogenous and exogenous growth factors.

Cell Division↗
PubMed1997

Surgical morbidity of neck dissection after chemoradiotherapy in advanced head and neck cancer.

The use of chemotherapy and irradiation for organ preservation attempts to eliminate the need for extensive surgery in patients with advanced squamous cell carcinoma of the head and neck (SCCHN). We sought to characterize the morbidity of surgery in patients who needed surgery after treatment with induction chemotherapy followed by simultaneous chemotherapy and radiotherapy (chemoradiotherapy). The surgical morbidity within the first 30 postoperative days of 17 patients treated in an organ preservation approach between July 1991 and December 1994 was compared with a control group of patients undergoing similar surgical procedures during the same period. The organ preservation study patients underwent surgical procedures consisting of 18 neck dissections and 5 resections of the primary site. Six patients in the organ preservation study group experienced 8 surgical complications within the first 30 postoperative days, and most complications were minor. There was no significant difference in the duration of surgery or length of hospitalization between study patients and matched controls. Our surgical complication rate (35.3%) was higher but not statistically different from that of the control group, and compared favorably to reports of surgical morbidity (44% to 61%) in the literature on patients treated with chemoradiotherapy. The lower complication rate seen in this study may be a reflection of early surgical intervention as part of our organ preservation study scheme, the preponderance of neck dissections performed, and the limited number of pharyngeal procedures performed.

Adult↗
PubMed1997

Effect of middle ear pressure change on middle ear mechanics.

The effect of graded variations in middle ear pressure on ossicular vibration was measured in 15 normal human temporal bone specimens. The displacement amplitude of the umbo and stapes head was measured at 16 frequencies between 0.2 kHz and 3.5 kHz at a constant sound pressure of 134 dB SPL at the tympanic membrane (TM) using a non-contacting video measuring system. Both negative and positive pressures decreased umbo and stapes vibration at low frequencies and slightly increased the vibration at higher frequencies. The effects were greater for negative pressure than for positive pressure. The change in stapes vibration was less than that of the umbo at low frequencies, but increased at higher frequencies. In some temporal bones, a small positive pressure produced improvement in stapes vibration at all frequencies. These effects were thought to be primarily due to an increased stiffness of the TM and a damping of ossicular vibration, due to stretching of the ossicular suspensory ligaments and the annular ligament of the footplate.

Aged↗
PubMed1997

Scanning laser Doppler vibrometry of the middle ear ossicles.

This paper describes measurements of the vibratory modes of the middle ear ossicles made with a scanning laser Doppler vibrometer. Previous studies of the middle ear ossicles with single-point laser Doppler measurements have raised questions regarding the vibrational modes of the ossicular chain. Single-point analysis methods do not have the ability to measure multiple points on the ossicles and, consequently, have limited ability to simultaneously record relative phase information at these points. Using a Polytec Model PSV-100, detailed measurements of the ossicular chain have been completed in the human temporal bone model. This model, when driven with a middle ear transducer, provides detailed three-dimensional data of the vibrational patterns of the middle ear ossicles. Implications for middle ear implantable devices are discussed.

Cadaver↗
PubMed1996

Combined use of superpulsed carbon dioxide laser and cryotherapy for treatment of facial rhytids.

OBJECTIVE: To compare the effect of superpulsed carbon dioxide (CO2) laser alone with that of cryotherapy in combination with CO2 laser in treatment of facial rhytids. DESIGN: A randomized prospective study. SETTING: Facial Plastic Surgery Clinic at Standford University Medical Center, Standford, Calif. PATIENTS: Twenty patients with perioral rhytids were randomized in the study, 11 in the laser group and 9 in the cryotherapy and laser group. INTERVENTION: Patients in the laser group were treated with superpulsed CO2 laser. Initially, the shoulders of rhytids were spot treated. The area was then wiped and rehydrated. The entire surface was then treated with a second pass. A third pass, if deemed necessary, was then used to treat the shoulders. Patients in the combined group underwent cryotherapy of the entire perioral region followed by CO2 laser treatment similar to that previously described. MAIN OUTCOME MEASURE: Improvement in facial rhytids with laser treatment alone was compared with improvement using cryotherapy and laser. A skin wrinkle grading system was used and patients were graded by 3 independent observers. Close-up photographs were obtained preoperatively and postoperatively. A questionnaire was filled out by each patient 1 month following treatment and was used to rate overall patient satisfaction. RESULTS: There was no statistically significant difference between the 2 groups regarding final outcome, amount of anesthetic agents required for each patient, or rate of complications. CONCLUSION: Superpulsed CO2 skin resurfacing alone is as effective as combined cryotherapy and superpulsed CO2 laser for treatment of perioral rhytids.

Cryotherapy↗
PubMed1996

Characterization of type I 5 alpha-reductase activity in DU145 human prostatic adenocarcinoma cells.

The conversion of testosterone (T) to dihydrotestosterone (DHT) has been demonstrated to be catalysed by at least two isoforms of human steroid 5 alpha-reductase, designated types I and II. Type II 5 alpha-reductase expression predominates in human accessory sex tissues, localized to the fibromuscular stromal compartment. The type I isoform predominates in skin, prostatic epithelia and, to a lesser extent, in prostatic fibromuscular stroma. The significance of the type I isoform to prostatic cellular growth and function remains undefined. In cultured DU145 cells, we evaluated the metabolism of [14C]-T and demonstrated the time-dependent formation of [14C]-DHT. Oxidative metabolism (conversion of [14C]-T to [14C]-androstenedione) and the formation of conjugated androgen metabolites occurred at a relatively low rate in the DU145 cells. Using human type I 5 alpha-reductase cDNA, Northern blot analysis of DU145 cell mRNA revealed high levels of type I isoform expression. Analogous probing of the DU145 cells with a human 5 alpha-reductase II cDNA failed to reveal expression of the type II isoform. The expression of functional type I activity has been confirmed pharmacologically using isoform-selective 5 alpha-reductase inhibitors. Reductive metabolism of [3H]-T in the DU145 cells was inhibited in a concentration-dependent manner by LY306089, a potent non-steroidal type I-selective inhibitor (IC50 = 10.0 nM). SKF105657, a steroidal type II-specific inhibitor was distinctly less active at inhibiting [3H]-DHT formation. LY306089 was a non-competitive inhibitor of type I 5 alpha-reductase in DU145 cellular homogenates with an apparent Ki value of 4.0 nM. These studies have identified and pharmacologically defined type I 5 alpha-reductase activity in an androgen-insensitive prostatic cancer cell line and provide the basis for additional investigations into the significance of type I 5 alpha-reductase to human prostatic pathophysiology.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1996

Responses of LNCaP prostatic adenocarcinoma cell cultures to LY300502, a benzoquinolinone human type I 5alpha-reductase inhibitor.

We evaluate the metabolic inhibitory, antiproliferative, and antisecretory effects of LY300502, a benzoquinolinone human-specific type I-selective steroid 5alpha-reductase inhibitor in LNCaP human prostatic adenocarcinoma cell cultures. Reductive metabolism of [3H-T] in the LNCaP cells was inhibited in a concentration-dependent manner by LY300502 (IC50 approximately 5.77 nM). The proliferative responses of LNCaP cells to LY300502 were examined in the presence of 0.1 NM testosterone (T), a concentration that stimulates maximal LNCaP cell numbers 40% above control levels. LY300502 significantly anatagonized T-induced stimulation of LNCaP cellular proliferation at concentrations greater that 10 nM (P<0.05), and at 1,000 nMcompletely blocked the mitogenic effects of T on LNCaP cells. In the absence of androgen, LY300502 had no effect on LNCaP cellular proliferation. In the presence of 100 nM T, an androgen concentration that maximally stimulates in vitro PSA production, LY300502 significantly antagonized T-induced PSA secretion at a concentration equal to or greater than 30 nM (P<0.05). These studies provide the basis for additional investigations into the pathophysiologic significance of type I 5alpha-reductase to prostatic cancer and the potential utility of selective inhibitors as therapeutic agents.

Adenocarcinoma↗
PubMed1996

Laser Doppler vibrometer (LDV)--a new clinical tool for the otologist.

We describe a laser Doppler system (LDS) that can be used clinically for the measurement of tympanic membrane (TM), malleus and prosthesis head displacement in response to sound inputs of 80-to 100-dB sound-pressure level (SPL). It also has the potential for use in the operating room to perform measurements of prosthesis and stapes displacement. The information provided by such testing gives the otologist knowledge of TM and ossicular function that is unique in evaluating middle ear function; it should help select the best type of reconstruction in a given case and direct us toward new and better methods of TM and ossicular reconstruction. The results of umbo displacement measurements in 95 human ears are reported. Examples are provided of LDS measurements in representative ears and how they can be of help to the clinician. The potential of multisite TM-displacement testing is demonstrated in two temporal bones, including before and after partial ossicular replacement prosthesis (PORP) insertion.

Audiometry, Pure-Tone↗
PubMed1995

Raloxifene (LY156758) produces antimetastatic responses and extends survival in the PAIII rat prostatic adenocarcinoma model.

The benzothiophene antiestrogen, raloxifene (LY156758), has selective estrogen pharmacological antagonist activity in rats. The PAIII rat prostatic adenocarcinoma model was used to evaluate the effects of this agent on the lymphatic and pulmonary metastasis and survival in tumor-bearing male Lobund-Wistar (LW) rats. Raloxifene was inactive against colony formation of PAIII cells in vitro. Similarly, following subcutaneous (s.c.) implantation of 10(6) PAIII cells in the tail, s.c. administration of raloxifene (2.0, 10.0, or 20.0 mg/kg/day) for 30 days failed to demonstrate cytoreductive activity against primary tumor growth in the tail. However, in these same animals, raloxifene administration produced significant (P < 0.05) inhibition of PAIII metastasis from the primary tumor in the tail to the gluteal and iliac lymph nodes (maximal responses = 89% and 81% from control values, respectively). PAIII metastasis to the lungs was significantly inhibited by raloxifene treatment. Numbers of pulmonary foci in PAIII-bearing rats were significantly (P < 0.05) reduced by raloxifene administration in a dose-related manner (maximal reduction = 97% from control values). In these animals, maximal regression of 20% for ventral prostate and 21% for seminal vesicle were also seen after raloxifene administration (P < 0.05 for both). Coadministration of E2B and raloxifene had no consistent antagonistic effect upon the antitumor responses produced by raloxifene. Raloxifene (40.0 mg/kg/day for 28 days) produced marked decreases in PAIII metastasis in the lymphatic and pulmonary components. Continued administration of the compound produced significant (P < 0.05) extension of survival of PAIII-bearing rats. Further studies are needed to define the maximal antitumor efficacy and the mechanism of action of raloxifene in urogenital solid tumor animal models. These data support the contention that raloxifene represents a class of active antimetastatic agents with potential efficacy in the treatment of hormone-insensitive human prostatic cancer.

Adenocarcinoma↗