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S B Shah

Publications and source records attributed to S B Shah.

At least 19 recordsLinked to original sources
PubMed2001

Sarcomere number regulation maintained after immobilization in desmin-null mouse skeletal muscle.

The serial sarcomere number of skeletal muscle changes in response to chronic length perturbation. The role of the intermediate filament desmin in regulating these changes was investigated by comparing the architectural adaptations of the tibialis anterior, extensor digitorum longus (EDL) and soleus from wild-type mice with those of homozygous desmin knockout mice after hindlimb immobilization. After 28 days, serial sarcomere number increased significantly in the lengthened wild-type tibialis anterior (by approximately 9%) and EDL (by approximately 17%). Surprisingly, muscles from desmin knockout mice also experienced significant serial remodeling, with the serial sarcomere number of the tibialis anterior increasing by approximately 10% and that of the EDL by approximately 27%. A consistent result was observed in the shortened soleus: a significant decrease in sarcomere number was observed in the muscles from both wild-type (approximately 26%) and knockout (approximately 12%) mice. Thus, although desmin is not essential for sarcomerogenesis or sarcomere subtraction in mouse hindlimb muscles, the results do suggest subtle differences in the nature of sarcomere number adaptation. We speculate that desmin may play a role in regulating the optimal arrangement of sarcomeres within the muscle or in sensing the magnitude of the immobilization effect itself.

Animals↗
PubMed2000

Laser in situ keratomileusis to correct residual myopia and astigmatism after radial keratotomy.

PURPOSE: To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) in selected post-radial-keratotomy (RK) eyes with residual myopia and astigmatism. SETTING: TLC-The Brea Laser Eye Center, Brea, California, USA. METHODS: Nine eyes of 6 patients who had had RK but had residual myopia and/or astigmatism had LASIK. All RK eyes had 8 radial incisions, were more than 1 year post-RK, had no epithelial inclusion cysts or corneal disease, and had had no subsequent ocular surgery. Follow-up was a minimum of 13 months, at which time uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, cycloplegic refraction, keratometry, central and peripheral pachymetries, intraocular pressure, and a subjective assessment of visual function were obtained. RESULTS: At the last follow-up, the mean spherical equivalent (SE) was -0.156 diopter (D) +/- 0.174 (SD). All eyes treated for distance vision had a UCVA of 20/25 or better. No patient lost BCVA. No intraoperative or postoperative complications occurred. Seven eyes had morning and evening measurements. The mean change in manifest SE from morning to evening was -0.143 D. Six of the 7 eyes (86%) had 0 to 1 Snellen line change in UCVA from morning to evening. The subjective questionnaire revealed a high degree of satisfaction with overall vision, minimal glare, and less fluctuation in daily vision than before LASIK. CONCLUSION: Laser in situ keratomileusis is safe and efficacious for reducing residual myopia and astigmatism in properly selected RK patients.

Astigmatism↗
PubMed2000

Chronic rhinosinusitis: allergy and sinus computed tomography relationships.

The management of chronic or recurrent rhinosinusitis problems is multifaceted and should include consideration of contributory and potentially correctable medical and anatomic factors. To date, the relationship between allergy and rhinosinusitis has not been clearly defined. The purpose of this study is to improve understanding of the relative roles of perennial and seasonal allergens in the cause of chronic rhinosinusitis. A retrospective review of 200 consecutive patients was carried out on patients who had chronic rhinosinusitis refractory to medical therapy and who subsequently underwent functional endoscopic sinus surgery. All of these patients had allergy testing for common perennial and seasonal inhalant allergens before surgery. Each patient had sinus CT imaging before undergoing the surgery. The CT scans of each patient were staged according to a validated, standardized grading system by investigators blinded to allergic profile. Allergy testing indicated that 84% of all patients tested positive for allergies. Moreover, 60% of all patients had significant allergic sensitivity; 52% of all patients had multiple allergen sensitivities. Furthermore, there was a predominance of perennial allergens, especially house dust mite over seasonal allergens. The vast majority of our patients undergoing functional endoscopic sinus surgery had concomitant allergy. This study highlights the potential contribution of perennial allergies to the development of rhinosinusitis. Given this direction, future studies may reveal that in the care of patients with perennial allergic rhinitis, early intervention with identification of the offending allergen(s), and subsequent treatment through avoidance, pharmacotherapy, and/or immunotherapy may help in the prevention of recurrent and chronic rhinosinusitis.

Animals↗
PubMed1999

Transverse/sigmoid sinus dural arteriovenous fistulas presenting as pulsatile tinnitus.

OBJECTIVE/HYPOTHESIS: Transverse/sigmoid sinus dural arteriovenous fistula (TSDAVF) is a diagnostically elusive entity that is critical for the otologist to account for, when confronted by pulsatile tinnitus in the face of normal otoscopy. Left untreated, TSDAVF may result in catastrophic outcome. We have previously proposed a grading system specifically for TSDAVF based on venous restrictive disease. Our objective was to assess the validity of this grading system for clinical severity and therapeutic outcome. METHODS: Through a retrospective review of 41 patients with TSDAVF, we evaluated clinical presentation, diagnostic evaluation, therapy, and outcome. Patients were classified into four grades based on the severity of venous restrictive disease as determined by superselective angiography. Our treatment algorithm combined compression therapy, transarterial embolization, and for more severe grades, surgery. RESULTS: Pulsatile tinnitus was the chief complaint of all the patients in this series, and of 90% of all cases of TSDAVF treated at our institution. While angiography remains the gold standard, magnetic resonance imaging/magnetic resonance arteriography is far superior to computed tomography scanning in detecting dural arteriovenous fistulas. As normal venous outflow gives way to aberrant cortical venous drainage in higher grades, there is a dramatically increased risk for adverse consequences with therapeutic intervention. Using our treatment algorithm, 82% of patients achieved clinical resolution of symptoms. Half of these patients had complete angiographic obliteration of their TSDAVF. CONCLUSIONS: The TSDAVF-specific grading system for the severity of venous restrictive disease is reflective of clinical presentation, fundamental in planning treatment, and predictive of therapeutic outcome.

Adolescent↗
PubMed1999

Transmucosal fine-needle aspiration diagnosis of intraoral and intrapharyngeal lesions.

OBJECTIVES: The effectiveness of fine-needle aspiration biopsy (FNAB) for the diagnosis of neck, thyroid, and salivary gland masses is well documented. Very few reports explore the potential of an intraoral FNAB approach for the diagnosis of submucosal lesions. We describe our technique and present case examples of pertinent differential diagnostic entities. We recommend an expanded role for FNAB of the oral cavity and oropharynx. STUDY DESIGN: Retrospective review. METHODS: A uniform technique was employed for transmucosal FNAB of 76 patients with intraoral masses. In applicable cases, cytology results were compared with traditional biopsy methods and permanent histopathologic specimens for accuracy. RESULTS: Our experience demonstrates the high sensitivity (93%) and specificity (86%) of intraoral FNAB when compared with biopsy by conventional means. FNAB provides distinct advantages for the cytologic diagnosis of submucosal lesions, which may be difficult to reach and adequately sample through conventional biopsy. FNAB of the tonsil and tonsillar fossa provides a safe and effective means of diagnosing both lymphoma and squamous cell cancer. Transmucosal FNAB via the mouth led to rapid diagnosis of a number of benign and malignant lesions. Applying this uniform FNAB technique, we had no significant complications. CONCLUSION: We recommend transmucosal FNAB as an effective means for highly accurate diagnosis of submucosal lesions of the oral cavity and oropharynx. CLINICAL RELEVANCE: Traditional biopsy techniques in the oral cavity may require anesthesia and may have diagnostic difficulties, particularly for submucosal lesions. Transmucosal FNAB overcomes these shortcomings by providing a minimally invasive means to rapid diagnosis of intraoral lesions.

Adult↗
PubMed1998

Perioperative management of von Willebrand's disease in otolaryngologic surgery.

von Willebrand's disease (VWD) is the most common hereditary bleeding disorder. Unchecked or improperly managed, VWD-associated hemorrhage can lead to catastrophic surgical outcome. Based on the authors' recent experience with 21 procedures in 12 patients, a contemporary protocol for successful perioperative management of VWD in otolaryngologic surgery is presented. In patients with VWD type 1 or 2a, desmopressin, a synthetic vasopressin analog, is administered both pre- and postoperatively to release von Willebrand factor (VWF) from storage sites. In type 2b or 3, a factor VIII concentrate rich in VWF is administered. In addition, a 10- to 14-day course of intravenous and/or oral Amicar (Immunex Corp., Seattle, WA) may be prescribed postoperatively. Intraoperatively, the surgical laser is used to further decrease blood loss and augment hemostasis. This medical and surgical protocol minimizes the risk of hemorrhage and of transfusion-related complications through the judicious use of preoperative and postoperative coagulation replacement products. Using these guidelines in a variety of otolaryngologic cases, the authors have had no bleeding complications at their institution.

Adenoidectomy↗
PubMed1998

Facial nerve surgery in the 19th and early 20th centuries: The evolution from crossover anastomosis to direct nerve repair.

The historical aspects of facial nerve (FN) anatomy and of Bell's palsy have long been favorite topics of otologic historians. Little attention has been paid, however, to the evolution of FN surgery, a subject with a remarkably rich and engaging history. In the early 13th century, Roland, an Italian surgeon, used a red hot iron to coapt severed nerve endings. In the 17th century, Ferrara, another Italian, sutured injured nerves with tortoise tendon dipped in hot red wine. It was not until the late 19th century that peripheral nerve suture became a subject of serious scientific study. Although it is ironic, the course of events suggests that the evolution of FN repair was greatly stimulated by the development of the modern mastoid operation. Whereas the simple mastoid operation practiced by Wilde (1853) and others carried little risk of FN injury, more adventuresome procedures such as radical mastoidectomy (Kessel, 1885) carried a much greater risk. The abundance of iatrogenic palsies during this era undoubtedly did much to motivate surgeons to seek a better means of restoring facial animation. Most surgeons would be surprised to learn that crossover anastomoses predated direct nerve repair by nearly half a century. In 1879, the German surgeon Drobnik performed the first facial-spinal accessory anastomosis. Over the next two decades, numerous articles were written (most notably by Sir Charles Balance and Harvey Cushing) on crossovers between the FN and cranial nerves IX, X, XI, and XII. Although a few tentative attempts at reapproximating severed FNs took place in the first two decades of this century, it was not until 1925 that an actual suture repair of an intratemporal injury was undertaken. This feat was first accomplished by the famous hand surgeon Sterling Bunnell and shortly thereafter by the otolaryngologist Robert Martin. The evolution of FN surgery in the days predating the operating microscope is a rich tapestry of colorful personalities and clashing egos, which saw promising advances relegated to obscurity and some previously obscure techniques become progressively more promising.

Anastomosis, Surgical↗
PubMed1997

Implants in rhinoplasty.

A variety of materials have been employed in rhinoplasty for augmentation and reconstruction. While autogenous tissue remains the mainstay of nasal implants and are the clear choice for structural and augmentation grafting of the nasal tip, limited availability and unpredictable resorption or remodeling have made homologous and synthetic implants important considerations for dorsal augmentation grafting. This section discusses categories of graft materials, their physical properties, harvesting and preparation technique, and advantages and disadvantages. An algorithm for nasal implants for specific indications in support and augmentation is presented.

Biocompatible Materials↗
PubMed1997

Misexpression of chick Vg1 in the marginal zone induces primitive streak formation.

In the chick embryo, the primitive streak is the first axial structure to develop. The initiation of primitive streak formation in the posterior area pellucida is influenced by the adjacent posterior marginal zone (PMZ). We show here that chick Vg1 (cVg1), a member of the TGFbeta family of signalling molecules whose homolog in Xenopus is implicated in mesoderm induction, is expressed in the PMZ of prestreak embryos. Ectopic expression of cVg1 protein in the marginal zone chick blastoderms directs the formation of a secondary primitive streak, which subsequently develops into an ectopic embryo. We have used cell marking techniques to show that cells that contribute to the ectopic primitive streak change fate, acquiring two distinct properties of primitive streak cells, defined by gene expression and cell movements. Furthermore, naive epiblast explants exposed to cVg1 protein in vitro acquire axial mesodermal properties. Together, these results show that cVg1 can mediate ectopic axis formation in the chick by inducing new cell fates and they permit the analysis of distinct events that occur during primitive streak formation.

Animals↗
PubMed1997

Acoustic neuroma surgery: outcome analysis of patient-perceived disability.

OBJECTIVE: Numerous studies have investigated the outcome of acoustic neuroma (AN) treatment using classical medical measures. In an effort to describe the long-term lifestyle consequences of AN removal from the patient's perspective, patients filled out detailed questionnaires concerning their functional status. STUDY DESIGN: This was a retrospective survey. SETTING: This study was performed at a tertiary referral center. PATIENTS: A total of 130 late postoperative acoustic neuroma patients were surveyed a minimum of 6 months following surgery (average, 39 months). Survey response rate was 65% (130/200). MAIN OUTCOME MEASURES: The main outcome measures were the patient's perception of their hearing, balance, facial expression, and eye function in relation to its impact upon the activities of daily life. A comparison of pretreatment with long-term posttreatment functional levels. RESULTS: When asked to designate their "most significant" symptom, hearing loss was by far most prevalent (61.3%), followed by balance troubles (14.3%) and facial weakness (10.1%). The relatively low incidence of facial weakness as the patient's dominant complaint was somewhat surprising. When considering the incidence of each symptom, women were more likely to complain of facial weakness, dry eye, and headache, whereas men had a marginally higher incidence of hearing loss and imbalance. Patient age had no apparent influence upon either the distribution or severity of symptomatic complaints. Both hearing in the tumor ear and overall auditory function (e.g., the ability to understand in a restaurant) tended to worsen following surgery. One finding, which was both unanticipated and intriguing, was the improvement in sound localization ability reported by 57% of patients following surgery. Although the proportion of patients complaining of frequent tinnitus increased postoperatively, the number of patients who found the tinnitus troublesome decreased markedly. In terms of balance function, only 31% preoperatively and 15% postoperatively described themselves as free of balance difficulties. An aid to ambulation (e.g., cane, walker) was needed in five patients (4%) preoperatively, two of whom regained the ability to walk independently following tumor removal. CONCLUSIONS: These functional outcome data provide much useful information to both patient and clinician to consider when contemplating the optimal course of AN management. Although virtually all acoustic neuroma patients have some degree of persistent symptoms over the long-term, the data indicates that most of these are attributable to the tumor itself as opposed to the after effects of its surgical removal. The relatively slight differences between preoperative and late postoperative symptom profiles was a rather unanticipated finding. As the degree of disability tends to increase with larger tumor sizes, these data tend to support a policy of early intervention.

Adolescent↗
PubMed1997

Socioeconomic impact of acoustic neuroma surgery.

OBJECTIVE: This study aimed to assess the impact of acoustic neuroma (AN) surgery on socioeconomic function. STUDY DESIGN: This study was a retrospective postal survey. SETTING: The study was performed at a tertiary referral center. PATIENTS: One hundred thirty late postoperative AN patients were surveyed a minimum of 6 months after surgery (average 39 months). The survey response rate was 65% (130 of 200). MAIN OUTCOME MEASURES: These included effect of AN surgery on employability, income, activities of daily living, social involvement, and psychological well-being. RESULTS: When comparing preoperative occupational status with latest follow-up, 2 of 125 (1.6%) became unemployed from their usual occupations. An additional 15 of 125 (12%) retired, attributing their retirement to the effects of the tumor itself (3), an aftermath of surgery (2), and causes unrelated to their AN (10). After AN removal, two formerly unemployed patients became employed. Among those remaining employed, there was no significant impact of surgery on either income or work responsibility. Return to normal activity was gradual: < or = 6 weeks, 31%; < or = 3 month, 64%; and < or = 6 months, 84%. Among activities of daily living, the tasks most often impaired (both before and after tumor removal) were ladder climbing and night driving, whereas dressing and bathing were seldom problematic. Overall, patients reported a minor decline in ability to perform routine daily activities after tumor removal. Social function (contact with friends, community involvement, and participation in sports) changed little after surgery. The incidence of both stress and depression decreased slightly after tumor removal. CONCLUSIONS: The economic, social, and psychological impact of AN and its surgical management appears to be relatively minor, with few individuals having life altering consequences.

Activities of Daily Living↗
PubMed1996

Structural changes in oocyte nucleoli of Xenopus laevis during oogenesis and meiotic maturation.

Immunoelectron microscopy with anti-nucleolin defined substructures within the multiple nucleoli of biosynthetically active stage II-III oocytes and within the nucleoli of relatively quiescent stage VI oocytes of Xenopus laevis. Dense fibrillar components (DFCs) of nucleoli from stage II-III oocytes consisted of nucleolonemas that radiated from a continuous DFC sheath surrounding fibrillar centers (FCs). Discernible granular regions (GRs) were absent in these same nucleoli. Conversely, stage VI oocyte nucleoli displayed compacted DFCs and prominent GRs. Immunofluorescence microscopy then tracked fibrillarin, nucleolin, and condensed DNA through oogenesis and into progesterone-induced meiotic maturation and nuclear breakdown. In stage II-III oocyte nucleoli, fibrillarin was enriched near the FC-DFC boundaries, while nucleolin was distributed throughout these same DFCs. Both proteins were enriched within the compacted DFCs of stage VI oocyte nucleoli. Staining with (DAPI) 4',6-diamidino-2-phenylindole showed condensed DNA within nucleolar FCs of both stage II-III and stage VI oocyte. Upon nuclear breakdown, we found fibrillarin and nucleolin in small particles and in the surrounding cytoplasm. Although we saw no trace of fibrillarin or nucleolin in nuclear remnants prepared just minutes later, DAPI-stained particles remained within these preparations, thus suggesting that FCs were at least slow to disassemble.

Animals↗
PubMed1995

Enhanced preservation of the auditory nerve following cochlear perfusion with nerve growth factors.

Survival of auditory neurons in the cochlea is thought to be an important factor in the success of cochlear implantations. Damage to the cochlear end-organ often produces loss of dendrites in the osseous spiral lamina. The authors have established a method that delivers water soluble pharmacologic agents to the cochlea using a mini osmotic pump with a polyethylene cannula that is inserted into the scala tympani via cochleostomy. The cannula is filled with an ototoxic agent, neomycin, that destroys the end-organ over the first 24 hours after insertion. Nerve growth factor (NGF), or a control substance, is placed in the pump reservoir and is pumped into the cochlea over a 2-week period. In this study, auditory nerve fibers in the osseous spiral lamina were counted in the apical, middle, and basal turns of the cochlea in 16 guinea pigs. At each location, fiber counts were significantly higher when neomycin was followed by perfusion with NGF, than when it was followed by infusion with control substances. The study demonstrates that NGF confers some protection against ototoxic induced degeneration of the auditory nerve in vivo.

Animals↗
PubMed1995

An extended study: protective effects of nerve growth factor in neomycin-induced auditory neural degeneration.

Intracochlear survival of auditory neurons is thought to be a factor contributing to the success of cochlear implantations. Damage to the cochlear end-organ is frequently associated with loss of neurites in the osseous spiral lamina. The authors have previously reported a model for long-term intracochlear administration of pharmacologic agents using a technique and device analogous to a cochlear implant. These studies suggest that nerve growth factor (NGF) protects the auditory nerve from the immediate neurotoxic effects of neomycin. The intent of the present investigation is to determine whether NGF can protect auditory neural elements from neomycin-induced degeneration after several weeks have elapsed between the neomycin perfusion and the administration of NGF. Neomycin was infused over 24 hours through an indwelling, intracochlear cannula attached to a mini osmotic pump to unilaterally destroy the cochlear end-organ. The pump perfused the cochlea with artificial perilymph for 2 weeks. Then, the pump reservoirs were surgically replaced; the new reservoirs delivered either NGF or artificial perilymph for an additional 2 weeks. Spiral ganglion cell densities were measured along Rosenthal's canal in the basal, middle, and apical cochlear turns. This investigation revealed that NGF prevented auditory nerve degeneration over the 2-week period, when compared to controls, and that the protective effect was greatest in the neural elements closest to the source of NGF.

Animals↗
PubMed1994

A model for long-term intracochlear administration of pharmacologic agents.

A technique is described that provides a method to study the effects of intracochlear pharmacologic agents on the degenerating auditory nerve. The model involves implanting a guinea pig with an osmotic minipump that allows slow perfusion of the cochlea over a period of hours to days with up to two water soluble substances. Neomycin and horseradish peroxidase, whose histopathologic effects on the cochlea are well known, are used in the present study to validate the efficacy of the system.

Animals↗
PubMed1991

Doubting atopy?

Sera of 37 patients attending the allergic clinic and of 10 normal healthy non-allergic controls were collected and in a double blind manner they were tested using phadiatop RIA for differentiation of patient's symptoms as due to atopy or otherwise without performing other troublesome investigations. It is an easy, less time consuming and reliable technique.

Double-Blind Method↗
PubMed1990

Pyruvicacidemia.

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Biotin↗