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Biomedical subjects

M J Shikowitz

Publications and source records attributed to M J Shikowitz.

At least 19 recordsLinked to original sources
PubMed1992

Clinical effects of photodynamic therapy on recurrent laryngeal papillomas.

Thirty-three patients with moderate to severe recurrent laryngeal papillomatosis underwent photodynamic therapy at our institution. All received 2.5 mg/kg of dihematoporphyrin ether intravenously either 48 or 72 hours prior to photoactivation with an argon pump dye laser system. Photosensitivity was the only side effect seen. Statistical analysis showed a significant decrease, by approximately 50%, in the average rate of laryngeal papilloma growth following treatment. The response was especially pronounced in patients with the worst disease. In addition, three patients have now remained free of disease for extended periods following photodynamic therapy. Latent infection with human papillomavirus continues to persist in clinically normal tissue following photodynamic therapy. The results and potential of this exciting new therapy for laryngeal papillomatosis are described.

Adolescent↗
PubMed1992

Comparison of pulsed and continuous wave light in photodynamic therapy of papillomas: an experimental study.

Papillomavirus infection of the upper aerodigestive tract is a serious and potentially life-threatening disease which can result in complete respiratory obstruction. Papillomas are the most common benign neoplasm of the larynx in children but have been shown to have an equal propensity to occur in adults. The hallmark of this disease is one of multiple recurrences despite adequate surgical removal, often resulting in a frustrating and prolonged clinical course. Multiple treatment modalities have been used throughout the years, unfortunately with limited success. Recent reports on the treatment of virally induced lesions with photodynamic therapy (PDT) using hematoporphyrin derivative (HPD) or its newly purified form dihematoporphyrin ether (DHE) as photosensitizing agents have appeared in the literature. The successful treatment of papillomas in both the animal model and humans holds great promise. The most commonly used activating light source has been the argon pumped-dye laser (ADL) which produces a continuous wave of coherent light at 630 nm. Although the ADL has proved efficacious in most studies, its cost, size, special cooling water requirements, and large electrical power requirements with limited power output have made it a less than desirable clinical tool. The gold vapor laser (GVL) has been recently proposed as a possible alternate light source for PDT. This laser appears to be more efficient and offers greater power output while requiring less electrical energy than the ADL. The GVL does not produce the same continuous wave light as the ADL but emits pulsed light with high peak power pulses. Some reports have shown a greater tumor response using the GVL at 628 nm, possibly because of greater tissue penetration from the high-peak power pulses. At this time, no studies have investigated the effects of pulsed light during PDT on virally induced papillomas. The present study was conducted to evaluate the efficacy of pulsed light from a GVL as compared to continuous wave light of the ADL in the treatment of papillomas with DHE phototherapy. Statistical analysis of the rate of tumor response, histological changes, and molecular analysis of viral DNA from the involved tissues were performed. Results have shown that the GVL did produce a greater initial rate of tumor response during the first 3 weeks after PDT but did not improve the overall cure rate. Histological and molecular analysis of the treated tissues demonstrated that similar results were obtained when either the ADL or GVL were used as activating light sources.

Animals↗
PubMed1991

Sudden sensorineural hearing loss.

Hearing is one of our most important senses and its sudden loss can be frightening and frustrating for the patient and his or her physician. Despite multiple reports of sudden SNHL over the years, we still do not have a universally accepted definition. This has led to further confusion in reporting and evaluating the treatment and prognosis of this disease. We generally define any SNHL occurring over 3 days as sudden SNHL. The overall incidence of this disease appears to be low. However, the true incidence may be higher, because those patients who spontaneously recover may never seek medical attention. The etiology is often difficult to identify, leaving a large population of patients labeled as idiopathic SNHL. Before accepting the idiopathic label, the physician must maintain a high level of suspicion to be sure that the SNHL is not a symptom of a larger underlying systemic disorder. Several theories have been proposed to try to explain SNHL. These include the infectious theory, vascular theory, and rupture theory. In addition to these, metabolic imbalances, drug toxicity, and various disease entities may contribute to sudden SNHL. Over the years, many treatment protocols have appeared in the literature, each claiming various rates of success. Unfortunately, they are often based on emotional and empiric considerations, because an exact etiology is unknown. Drugs have been chosen from several categories including the following: vasodilators, diuretics, anticoagulants, plasma expanders, corticosteroids, and contrast material. These medications have been used singly or in combination therapies. One must always be aware of the potential side effects. One factor that appears to be constant in each reported therapy is that those patients who seek medical attention early do better. The type of hearing loss also seems to play a role in the outcome of sudden SNHL; patients with low-frequency hearing losses or upward-sloping audiograms have a better prognosis. The patient must take the first step in seeking medical attention. Once the problem has been recognized, prompt attention by the physician to the medical workup and timely initiation of therapy will offer the patient the best possible chance for recovery. Time is often the greatest factor in the overall recovery, and the physician should reassure the patient that everything is being done to speed this along. However, patience may be the greatest healer of all.

Clinical Protocols↗
PubMed1991

Endolaryngeal jet ventilation: a 10-year review.

Jet ventilation for microsurgery of the larynx has been in common use at our institution since 1978. There were 942 cases performed, with ages ranging from 7 days to 90 years. A specially modified laryngoscope with multiple ports into which a 14- or 16-gauge ventilation needle can be advanced just distal to the vocal cords simplifies this form of anesthesia and ventilation. Jet ventilation has been advocated in place of conventional ventilation methods during carbon dioxide laser surgery because it eliminates the potential fire hazard of the endotracheal tube and allows superior visibility of the vocal cords. Despite these advantages, it is still not in common use. We will review the airway mechanics and special anesthesia considerations that make jet ventilation a safe and time-proven technique.

Adolescent↗
PubMed1990

Dihematoporphyrin ether-induced photosensitivity in laryngeal papilloma patients.

Twenty-six patients with recurrent laryngeal papillomatosis received 2.5 mg/kg of Dihematoporphyrin Ether (DHE) intravenously prior to photodynamic therapy. All patients experienced some degree of photosensitivity, the only known side effect of DHE. Reported reactions included mild erythema and inflammation (88%), swelling (58%), blistering (23%), ocular discomfort (61.5%), pruritus (38%), and skin hyperpigmentation (46%). Length of sensitivity ranged from 4-17 weeks, with an average duration of 9 weeks. No long-term debilitating sequelae were noted. Degree of skin reaction mainly depended on how compliant the patient was in following precaution instructions. Although restrictive precautions were often difficult to strictly adhere to, most patients felt the potential benefits of the therapy far outweighed any inconvenience.

Adolescent↗
PubMed1989

Biodistribution of indium 111-labeled dihematoporphyrin ether in papillomas and body tissues. Relevance to photodynamic therapy.

Hematoporphyrin derivative and its newly purified form, dihematoporphyrin ether, have been shown to localize selectively in malignant tissues and virally induced papillomas. Its use as a probe to distinguish tumors from normal tissues has been largely based on its fluorescence when activated by UV light. These findings are largely subjective, and a direct correlation to its use as a photosensitizing agent to selectively kill transformed cells when activated by an appropriate wavelength of light could not be made. The efficacy of dihematoporphyrin ether photodynamic therapy to selectively kill papillomavirus-transformed cells is based on the increased localization of dihematoporphyrin ether within these tissues as compared with normal tissues. Using cottontail rabbit papillomavirus, cutaneous papillomas were induced on the backs of Dutch belted rabbits. Dihematoporphyrin ether was labeled with indium 111 and intravenously injected into the rabbits. The animals were scanned twice daily for indium 111 activity on a large-field-of-view gamma camera. At 50 hours after injection, the rabbits were killed and papillomas, skin, and major organs collected for biodistribution studies. The results of this study and their relationship to dihematoporphyrin ether photodynamic therapy for the treatment of virally induced papilloma disease is discussed.

Animals↗
PubMed1988

The pathologic effects of photodynamic therapy on the larynx. Experimental study.

Using an argon pump dye laser at a wavelength of 630 nm, varying amounts of energy (10 to 170 J/cm2) were delivered to the presensitized (hematoporphyrin derivative) canine larynx. There appear to be four energy zones that result in progressive degrees of tissue response. Between 10 and 40 J/cm2 the larynx appears normal, with only mild erythema noted at 60 J/cm2. Above 100 J/cm2 moderate to severe erythema and edema were seen, with two upper-airway deaths observed. Transmission pattern analysis revealed that by either increasing the total energy applied and/or positioning the cylindrical diffuser tip at different levels of the larynx, the entire structure including the undersurface of the vocal cord and subglottic region could be exposed to red light.

Animals↗
PubMed1988

Histological and molecular analysis of cottontail rabbit papillomavirus-induced papillomas treated with hematoporphyrin derivative photodynamic therapy.

The clinical regression of cottontail rabbit papillomavirus-induced cutaneous papillomas on Dutch-belted rabbits following treatment with hematoporphyrin derivative photodynamic therapy was recently reported. Those papillomas that underwent total regression failed to recur at 18 months. Tissues from totally regressed papillomas and adjacent sites failed to reveal the presence of papilloma on histological examination. These findings were confirmed by the absence of viral DNA following analysis by Southern blots for cottontail rabbit papillomavirus viral copy number and DNA restriction pattern. Partially regressed papillomas and untreated papillomas revealed histologically typical papillary features with approximately equal amounts of viral DNA.

Animals↗
PubMed1988

Anatomic reconstruction and functional rehabilitation of oromandibular defects with rigid internal fixation.

Fifteen consecutive patients undergoing extensive surgery for head and neck cancer involving the oral cavity and oropharynx were reconstructed using the technique of rigid internal fixation combined with various vascularized flaps. The follow-up ranged from 6 to 18 months. Modifications in various myocutaneous or vascularized free flaps combined with an analysis of the radiation physics necessary to make this procedure a viable alternative for immediate and delayed mandibular reconstruction will be discussed. Consistently satisfactory functional and cosmetic results have been achieved.

Adult↗
PubMed1987

Thermal effects of photodynamic therapy on the larynx. Experimental study.

Whether cell death in carcinoma of the larynx during photodynamic therapy is due to singlet oxygen formation or mild hyperthermia is not resolved. When various experimental tumors were previously heated within the range of 41 degrees C to 43 degrees C, selective destruction was found. A canine model was used by placing a thermocouple probe into the vocal cord and then varying the total energy (10 to 150 J/cm2), using a 630-nm dye laser; a temperature rise of only 0.5 degrees C to 2.1 degrees C was found. Thus, the thermal effects generated within the larynx (final temperature, 34.9 degrees C to 37.1 degrees C) should be insufficient to act alone in achieving a therapeutic response in either tumor tissue or destruction of normal epithelium.

Animals↗
PubMed1987

Supraglottic hemangioma during pregnancy.

A 37-year-old woman, gravida 10, para 1-0-8-1, presented in her second trimester of pregnancy with complaints of frequent sore throats, change in voice quality, and recumbent dyspnea. These symptoms were noted initially during her previous pregnancy, and resolved after delivery. She was found to have a supraglottic hemangioma which occluded 40% of her upper airway. This lesion was noted to dramatically involute beginning at 36 weeks' gestation. The supraglottic hemangioma is a very rare cause of dyspnea in pregnancy. Its growth during pregnancy and regression postpartum is possibly related to the effects of estrogen and progesterone.

Adult↗
PubMed1986

Hematoporphyrin derivative therapy of papillomas. Experimental study.

Hematoporphyrin derivative has been shown to selectively localize in malignant tissues and chemically induced animal papillomas. It is a powerful photo-sensitizing agent that can cause destruction and death of tissues in which it has localized by the generation of singlet oxygen when activated by light of the appropriate wavelength (photodynamic therapy [PDT]). Laryngeal papillomas are rapidly growing benign epithelial neoplasms with a clinical course marked by multiple recurrences after surgical removal. Before considering PDT as a therapeutic modality in the treatment of this debilitating disease we developed an animal model for experimentation. Using the cottontail rabbit papillomavirus, sometimes referred to as the Shope papillomavirus, large cutaneous papillomas were induced on the backs of Dutch Belted rabbits. Following intravenous administration of hematoporphyrin derivative, PDT was delivered with white light. Marked regression of the papillomas was noted with replacement by normal hair-bearing skin. The clinical implications of this work to the control of laryngeal papillomatosis is discussed.

Animals↗
PubMed1986

Cardiac complications of suspension laryngoscopy. Fact or fiction?

A nonselective, prospective study of 100 consecutive patients undergoing suspension laryngoscopy was undertaken to observe the cardiac ischemic changes related to pharyngeal and laryngeal manipulation. Blood pressure, heart rate, rhythm, and cardiac response were monitored before, during, and after surgery. No significant changes were observed in normal, hypertensive, or high-risk patients. These findings differ from those previously reported.

Adult↗
PubMed1986

Bilateral vocal cord paralysis following endotracheal intubation.

Bilateral vocal cord paralysis following endotracheal intubation is an uncommon cause of respiratory obstruction. We report one case, adding to ten previously identified. We dissected eight human cadaver larynges and noted the path of the anterior ramus of the recurrent laryngeal nerve. It appeared to be particularly vulnerable to compression injury as it passed between the arytenoid cartilage and the thyroid lamina. This point was confirmed by histologic sections of intubated larynges.

Aged↗
PubMed1986

Squamous metaplasia in the trachea: the tracheotomized rabbit as an experimental model and implications in recurrent papillomatosis.

Squamous metaplasia following tracheotomy has been well documented. Most studies have dealt primarily with changes at--or adjacent to--the cuff site and have failed to evaluate its effect in the distal trachea. We have used rabbits as experimental models for the induction of tracheal squamous metaplasia, using uncuffed tracheotomy tubes. Rabbits were routinely killed 24, 36, 48, 72, 120, and 168 hours posttracheotomy, and the entire larynx, trachea, and main-stem bronchi were step-sectioned for histologic examination. Patchy areas of squamous metaplasia were found in all rabbits with tracheotomy equal to or longer than 48 hours. The metaplasia appeared to increase with time of intubation. Induction of squamous metaplasia (following tracheotomy as a contributing factor to the spread of laryngeal papillomatosis) is discussed.

Animals↗
PubMed1986

Sphenoid sinus mucocele masquerading as a skull base malignancy.

Mucoceles of the sphenoid sinus are rare. Only occasional reports have appeared in the medical literature since they were first described by Berg in 1889. The sphenoid sinus lies deep within the skull at the crossroads of 13 sensitive structures. The presence of a sphenoid sinus mucocele may be accompanied by a wide variety of signs and symptoms depending upon which of these structures are involved. The majority of these lesions are initially misdiagnosed as malignancies leading to increased patient morbidity and possible mismanagement. We present two cases of sphenoid sinus mucoceles which presented with a variety of neurological signs and symptoms. The radiographic findings were felt to be consistent with skull base malignancies. The diagnosis was corrected only after surgical exploration of the sphenoid sinus revealed a mucocele.

Diagnostic Errors↗