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Biomedical subjects

R L Saunders

Publications and source records attributed to R L Saunders.

At least 19 recordsLinked to original sources
PubMed2000

Characterization of the spermiation response, luteinizing hormone release and sperm quality in the American toad (Bufo americanus) and the endangered Wyoming toad (Bufo baxteri).

Spermiation and LH release in response to several methods of LHRH administration were assessed in the American toad (Bufo americanus), and the most successful method was tested in the endangered Wyoming toad (Bufo baxteri). Specific objectives were to: (1) compare spermiation responses and plasma LH concentration after invasive and non-invasive LHRH treatments; (2) evaluate sperm production in response to different LHRH dosages; (3) characterize the timing of sperm release post LHRH treatment; and (4) assess sperm quality (motility, viability, morphology and acrosomal status). Male American toads were administered 4 microg LHRH by one of four routes: (1) intraperitoneal injection (i.p.); (2) subcutaneous injection (s.q.); (3) dorsal dermis absorption (d.d.a.); and (4) ventral dermis absorption (v.d.a.). Aspermic urine only was collected from saline-treated controls and d.d.a. animals. Several v.d.a. animals released spermic urine; however, all LHRH-injected toads released spermatozoa. I.p. animals produced higher sperm and LH concentrations than s.q. animals. The spermiation response in animals treated i.p. with 1 microg LHRH was similar to that in animals treated with 4 microg, but lower LHRH dosages tested produced inferior responses. Sperm production in responsive animals increased over time during the 12-h sampling interval. Regardless of treatment, most American toad spermatozoa were motile, viable, and acrosome-intact. Endangered Wyoming toads were treated i.p. with 4 microg LHRH, and spermic urine was collected. Although most spermatozoa were viable and acrosome-intact, a considerable percentage possessed structurally abnormal heads. A single i.p. injection of LHRH appears to be a reliable and safe method for controlling spermiation in toads and may be useful for assisting endangered amphibian propagation.

Acrosome↗
PubMed2000

Effects of pollen load size and composition on pollen donor performance in wild radish, Raphanus sativus (Brassicaceae).

A critical concern in the debate over the importance of sexual selection in plants is whether the nonrandom mating demonstrable in greenhouse crosses can occur in the field. Field populations likely experience smaller and more variable pollen load sizes than those that have been used in many greenhouse experiments. Therefore, we performed a greenhouse experiment in which we varied both pollen load size and composition in wild radish, Raphanus sativus, and examined the paternity of seeds. We used five maternal plants and four pairs of pollen donors. We were able to produce pollen loads of 40, 118, and 258 grains per stigma. The smallest of the pollen loads was scant enough to result in a slight, but significant reduction in seed number per fruit. While variation in pollen load composition significantly affected the proportions of seeds fathered by different donors, variation in pollen load size did not. The relative performance of different donors was constant across pollen load sizes, suggesting that, for this species, differential performance of pollen donors can occur at pollen load sizes that are likely to occur in field populations.

Journal Article↗
PubMed2000

Shoulder numbness in a patient with suprascapular nerve entrapment syndrome: cutaneous branch of the suprascapular nerve: case report.

OBJECTIVE AND IMPORTANCE: The ability to diagnose peripheral nerve disorders is dependent on knowledge of the anatomic course and function of the nerves in question. The classic teaching regarding the suprascapular nerve (SScN) is that it has no cutaneous branches, despite the fact that a cutaneous branch was first reported in the anatomic literature 20 years ago. CLINICAL PRESENTATION: We describe a case of a 35-year-old male patient who presented with right shoulder pain and atrophy and weakness of the right supra- and infraspinatus muscles. During the examination, he was also noted to have an area of numbness involving the right upper lateral shoulder region. Electrical study results were consistent with SScN entrapment at the suprascapular notch. INTERVENTION: The patient underwent surgical decompression 7 months after the onset of his symptoms. The patient noted resolution of his shoulder pain immediately after the procedure, and his shoulder sensory disturbance had improved by 2 weeks. At 9 months after surgery, he remained pain-free, his shoulder sensation was normal, and his motor abnormalities had improved significantly. CONCLUSION: This case provides clinical evidence for the presence of a cutaneous branch of the SScN, as described in cadaveric studies. Although shoulder numbness demands a search for alternative diagnoses, it does not necessarily exclude the diagnosis of SScN entrapment.

Adult↗
PubMed1998

Four-level cervical corpectomy.

STUDY DESIGN: Retrospective analysis of 31 cases of cervical spondylotic myelopathy treated by four-level subaxial cervical corpectomy. OBJECTIVE: To determine whether extremes of anterior decompression and fusion have inordinate or unique levels of morbidity. SUMMARY OF BACKGROUND DATA: There is a paucity of data on experience with four-level corpectomy. However, counsel against such surgery can be found. MATERIALS AND METHODS: The records and studies of 31 consecutive cases of cervical spondylotic myelopathy, treated by four-level corpectomy, were retrospectively analyzed. Patients in 26 cases were observed longer than 2 years. No hardware was used in the procedures. External orthosis, worn for 6 months, was a Philadelphia-type collar in 25 patients and a halo vest in 6. RESULTS: Three patients died within 3 weeks of surgery (9.7%). Delayed radiculopathy occurred in four patients after surgery, three had acute graft complications, and one had pseudomeningocele, for a morbidity rate of 25.8%. There was no infection or worsened myelopathy. CONCLUSIONS: No unique morbidity is associated with extremes of subaxial decompression when compared with surgery of lesser extent.

Aged↗
PubMed1997

Absence of tetrodotoxins in a captive-raised riparian frog, Atelopus varius.

Bufonid frogs of the genus Atelopus contain two classes of skin toxins, namely the steroidal bufadienolides and the water-soluble tetrodotoxins. Frogs of the Panamanian species Atelopus varius have now been raised in captivity and levels in skin extracts of bufadienolides and of tetrodotoxin-like compounds assessed, using inhibition of [3H]ouabain binding and inhibition of [3H]saxitoxin binding, respectively. Levels of ouabain equivalents, corresponding to bufadienolides, were comparable to those found in wild-caught frogs from the same population in Panama, while tetrodotoxin-like activity was undetectable. The results strongly implicate environmental factors, perhaps symbiotic microorganisms, in the genesis of tetrodotoxins in the skin of frogs of the genus Atelopus, while indicating that the frog itself produces the skin bufadienolides.

Amphibian Venoms↗
PubMed1997

Estimates of weight that subjects can lift frequently in functional capacity evaluations.

BACKGROUND AND PURPOSE: This study was designed to determine whether the maximum weight that can be lifted during 33% to 67% of a workday (weight lifted frequently) can be accurately predicted from other data gathered during a functional capacity evaluation (FCE). The best equations for estimating weight lifted frequently were also identified, and the interrater reliability for measurements obtained during a 6-day FCE was calculated. SUBJECTS: A retrospective chart audit was conducted of clients (36 female, 93 male) who completed 22-hour FCEs during a 6-day period. Ninety subjects had spinal problems, and 39 subjects had injuries not involving the spine. Subjects were randomly assigned to a model estimation group (n = 109) or a cross-validation group (n = 20). METHOD: A stepwise multiple regression analysis identified the best predictors of weight lifted frequently, with subjects lifting from four different heights. The resulting equations were used to predict the weight for the cross-validation group, and predicted weights were compared with observed weights using t tests and correlation coefficients. RESULTS: Regression equations explained between 27.3% and 93.0% of the variance in weight, with standard errors of estimation between 1.09 and 5.72. No differences between the mean observed and predicted scores were found when estimates were based on weight only occasionally lifted (maximum weight that could be lifted up to 33% of a workday). CONCLUSION AND DISCUSSION: Estimates of weight lifted frequently based on weight lifted occasionally can be made, but the usefulness of these estimates is questionable. Clinicians should use caution when using estimations of weight lifted for return-to-work recommendations. [Saunders RL, Beissner KL, McManis BG. Estimates of weight that subjects can lift frequently in functional capacity evaluations.

Adult↗
PubMed1996

Serum silicon levels are elevated in women with silicone gel implants.

The metabolic fate of silicone gel leaked into the body from an implant is unknown. In this study, serum from 72 women with silicone gel breast implants and 55 control women was blindly assayed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elemental silicon. Samples were processed using materials free of silicon. The mean silicon level in controls was 0.13 +/- 0.07 mg/l (range 0.06-0.35 mg/l), while in implant patients, the mean was significantly higher at 0.28 +/- 0.22 mg/l (range 0.06-0.87 mg/l) (P < 0.01, Student's t-test with correction for unequal variances). Using the mean of the control group + 2 SD as a cutoff for normal range (0.27 mg/l), 25/72 (34.7%) implant patients exceeded this value, compared with 2/55 (3.6%) controls. There was no significant correlation between past rupture of one or both implants, current rupture at the time of the blood draw or the number of years with implants and silicon levels. The results suggest that elevations of serum silicon are seen in many women with silicone gel breast implants. The kinetics of this elevation and the actual chemical species of the measured silicon remain to be determined.

Adult↗
PubMed1996

Factors related to successful work hardening outcomes.

BACKGROUND AND PURPOSE: The purpose of this study was to identify factors that predict successful work hardening outcomes. Two measures of success were used: return to work and case closure (ie, resolution of medical treatment issues). SUBJECTS: Persons with spine-related injuries who completed a work hardening program were the subjects. One hundred fifteen subjects participated in a 3-month follow-up survey, and 111 subjects participated in a 12-month follow-up survey. METHODS: Data were collected on subject characteristics, treatment history, job factors, program payer, and program factors. Subjects were contacted by telephone at 3 and 12 months after program completion to determine work status. Logit analysis was used to identify predictors of successful versus unsuccessful outcomes. RESULTS: Three months after program completion, 68% of the subjects had returned to work and 86% had successful case closure. Twelve months after program completion, 77% of the subjects had returned to work and 90% had successful case closure. The more treatment subjects received prior to entering the program, the less likely they were to be working or achieving case closure following treatment. Subjects' work status and initial time off of work were factors predicting early return to work, but not 12 months after program completion. Subjects who were working with an attorney were less likely to achieve case closure than those who were not working with an attorney. Subjects who were satisfied with the program were more likely to have achieved case closure or return to work than those who were not satisfied with the program. CONCLUSION AND DISCUSSION: Several factors have been identified that predict successful work hardening outcomes. This information can be used to identify clients who are unlikely to benefit from work hardening.

Adult↗
PubMed1995

Elevated serum silicon levels in women with silicone gel breast implants.

The metabolic fate of silicone gel leaked from an intact or ruptured prosthesis is unknown. In this study, serum was blindly assayed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elemental silicon in 72 women with silicone gel breast implants and 55 control women (mean age 48 yr, both groups). Blood was drawn and processed using silicon-free materials. The mean silicon level in controls was 0.13 +/- 0.07 mg/L (range 0.06-0.35 mg/L), whereas in implant patients, the mean was significantly higher at 0.28 +/- 0.22 mg/L (range 0.06-0.87 mg/L) (P < 0.01, Student's t-test with correction for unequal variances). Using the mean of the control group + 2 SD as a cutoff for normal range (0.27 mg/L), 25/72 (34.7%) implant patients exceeded this value, compared with 2/55 (3.6%) controls. There was no significant correlation between past rupture of one or both implants, current rupture at the time of the blood draw, or the number of years with implants and silicon levels. The results suggest that serum silicon levels are elevated in many women with silicone gel breast implants. The chemical species involved and kinetics of this elevation remain to be determined.

Breast Implants↗
PubMed1995

On the pathogenesis of the radiculopathy complicating multilevel corpectomy.

Postoperative fifth cervical radiculopathy has been described after cervical corpectomy. One explanation for this complication is thought to be the factor of traction on cervical roots caused by a shifting of the spinal cord consequent to decompression. This theory is supported by our experience with 176 patients undergoing corpectomies for whom a lesser width of decompression all but eliminated the complication.

Adult↗
PubMed1992

Continuous infusion of intrathecal morphine to control acquired immunodeficiency syndrome-associated bladder pain.

A 36-year-old man with acquired immunodeficiency syndrome had incapacitating dysuria and vesical pain secondary to interstitial cystitis. When medical management and suprapubic urinary diversion failed to control the symptoms the patient was started on subarachnoid morphine sulfate. Bupivacaine was added 1 year later via an implanted Therex M-3000 implantable continuous infusion pump, which has continued successfully for more than 18 months. We believe that subarachnoid narcotics and other analgesic agents, such as clonidine, bupivacaine hydrochloride and baclofen, may prove equally valuable in the treatment of bladder spasm and pain. Furthermore, implanted intrathecal ports and pumps may have less associated risk of infection than the percutaneous vascular access catheters presently used for the continuous delivery of medications in immunosuppressed patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Geniculate ganglion: anatomic study with surgical implications.

The geniculate ganglion and adjacent segments of the facial nerve were dissected in 11 human temporal bones to study the extent and distribution of ganglion cells. A histologic basis for the use of geniculate ganglionectomy as the treatment for geniculate neuralgia was sought. In 9 of 11 specimens (81.8%), the ganglion cell bodies appeared to be aggregated at the apex of the genu close to the origin of the greater superficial petrosal nerve. The mean ratio of the width of the ganglion cell cluster to the width of the facial nerve trunk at the level of the genu was 0.4. In two specimens, significant anatomic variation was present. One specimen showed extension of cell bodies into the labyrinthine segment of the facial nerve; another specimen showed a single ganglion cell in the region of the genu. These findings lead us to postulate that geniculate ganglionectomy may be ineffective as the sole treatment for certain cases of geniculate neuralgia, and that nervus intermedius section may also be required to achieve a more complete deafferentation.

Facial Nerve↗
PubMed1991

Neurosurgical complications after intranasal ethmoidectomy.

Intranasal ethmoidectomy is a common otolaryngological procedure. Despite the potential for serious intracranial complications, there is a paucity of reports describing the neurosurgical complications of the procedure. Two patients with intracranial complications of intranasal ethmoidectomy, and the relevant medical literature, are reviewed. The anatomy of the ethmoid air cells and their relation to the intracranial cavity are described. The importance of definitive, emergent repair with attention to the potential for vascular injury is discussed.

Aged↗
PubMed1991

Repair of a cerebrospinal fluid perilymph fistula primarily through the middle ear and secondarily by occluding the cochlear aqueduct.

A 35-year-old man had a 5-year history of fluctuating hearing loss in his only hearing ear. History and diagnostic tests indicated a perilymph fistula, a diagnosis subsequently confirmed by exploration. Primary and secondary repairs temporarily ameliorated symptoms. A spinal fluid to middle ear fluid pathway was identified by radioactive tracer. A patent cochlear aqueduct indicated on computed tomography scan was found and repaired through a posterior cranial fossa approach. Hearing was preserved, remaining relatively stable during the 2-year follow-up period.

Adult↗
PubMed1991

Central corpectomy for cervical spondylotic myelopathy: a consecutive series with long-term follow-up evaluation.

Since 1984, a consecutive series of patients with cervical spondylotic myelopathy has been treated by central corpectomy and strut grafting. This report focuses on 40 cases operated on between 1984 and 1987 and followed from 2 to 5 years. The perioperative complication rate was 47.5%, with a 7.5% incidence of persistent sequelae: severe C-5 radiculopathy in one patient, swallowing dysfunction in one, and hypoglossal nerve palsy in one. No single factor (age, duration of symptoms, or severity of myelopathy) was absolutely predictive of outcome; however, syndromes of short duration had the best likelihood of cure. Similar outcomes were associated, individually, with long duration of symptoms, age over 70 years, and severe myelopathy. After factoring a 5% regression of improvement, the long-term cure rate was 57.5% and the failure rate was 15%. Myelopathy worsening was not documented.

Cervical Vertebrae↗
PubMed1991

Geniculate neuralgia: the surgical management of primary otalgia.

Intractable, unexplained deep-ear pain presents a rare, albeit significant problem in otolaryngological and neurosurgical practice. The authors review their experience with 18 cases of primary otalgia during the past 15 years. A total of 31 surgical procedures were performed. Seventeen patients had sequential rhizotomies and one patient had microvascular decompression alone. Based on the clinical diagnosis, the nerves sectioned were singly or in combination: the nervus intermedius (14 patients), geniculate ganglion (10 patients), ninth nerve (14 patients), 10th nerve (11 patients), tympanic nerve (four patients), and chorda tympani nerve (one patient). Microvascular decompression of the involved nerves was undertaken in nine patients, in whom vascular loops were discovered. Adhesions (six patients), thickened arachnoid (three patients), and benign osteoma (one patient) were other intraoperative abnormalities noted. The overall success of these procedures in providing pain relief was 72.2%, and the mean follow-up period was 3.3 years (range 1 month to 14.5 years). There was no surgical mortality. Expected side effects were: decreased lacrimation, salivation, and taste related to nervus intermedius nerve section, and transient hoarseness and diminished gag related to ninth and 10th nerve section. Four patients developed sequelae consisting of sensorineural hearing loss, vertigo, and transient facial nerve paresis. One patient had a cerebrospinal fluid leak and another developed aseptic meningitis as postoperative complications. Except when primary glossopharyngeal neuralgia is the working diagnosis, a combined posterior cranial fossa-middle cranial fossa approach is recommended for adequate exploration and/or section of the fifth, ninth, and 10th cranial nerves as well as the geniculate ganglion and nervus intermedius.

Adult↗