Biomedical subjects

H B Neel

Publications and source records attributed to H B Neel.

At least 55 records · Page 3Linked to original sources

PubMed1983

Thermal considerations in murine tumor killing using hematoporphyrin derivative phototherapy.

Tumor cell killing utilizing hematoporphyrin derivative (HPD) phototherapy was studied in a murine tumor model to assess the relative importance of intratumor temperature in causing the tumoricidal effect. Temperature measurements and tumor killing without HPD strongly suggest that HPD phototherapy as reported previously by other workers has at least partially a hyperthermic effect. Also, it is shown that, in this tumor model, tissue light attenuation restricts the radius of action of the light-HPD interaction to approximately 4 mm.

Adenocarcinoma↗

PubMed1983

Current thinking on tonsillectomy and adenoidectomy.

Tonsillectomy and adenoidectomy, though less frequently performed now than in the 1930s, remain among the most common surgical procedures in the United States. The need for and benefits of tonsillectomy and adenoidectomy have been a source of controversy for several decades. Nonetheless, there are situations in which these procedures definitely are beneficial. Tonsillectomy and adenoidectomy are two distinct procedures with separate indications, and they are performed concurrently only when the specific indications for each coexist. Tonsillectomy is indicated by recurrent tonsillitis, peritonsillar abscess, chronic tonsillitis, tonsillar neoplasm, or tonsillar hypertrophy that is obstructive to the upper aerodigestive tract (respiratory distress, dysphagia, or interference with performance of an adenoidectomy). Adenoidectomy is indicated for nasal airway obstruction due to adenoidal enlargement from hypertrophic or inflammatory processes. Although correlation exists among obstructive adenoids, mouth breathing, and dentofacial anomalies, present evidence is not sufficient to justify adenoidectomy solely on the basis of craniofacial or dentofacial abnormalities. Today, elimination of an occult source of infection (once called focal infection) in patients with disorders such as rheumatic fever or serous otitis media is not a valid indication for either operation. Contraindications to tonsillectomy and adenoidectomy include bleeding disorders, familial anesthetic intolerance, velopharyngeal insufficiency, and concurrent disease that may enhance operative risks. Like all surgical procedures, tonsillectomy and adenoidectomy entail morbidity and risk of mortality. The most frequent complication of these operations is hemorrhage. Risk of mortality is approximately 0.006%. Mortality and morbidity can be minimized by appropriate preoperative evaluation, complete control of the airway with endotracheal anesthesia, and meticulous surgical technique.

Adenoidectomy↗

PubMed1983

Implants of Gore-Tex.

Pieces of an expanded, fibrillated, polytetrafluoroethylene material (Gore-Tex), were evaluated as implants for application in facial plastic augmentation and reconstructive surgery. The Gore-Tex cylinder material, which has an average internodal spacing of 30 microns, became permeated with viable connective tissue. Few histiocytes and giant cells accumulated at the implant site, a sign that little chronic inflammation and foreign-body reaction were present. Mature connective tissue around the implant appeared to form a strong supporting envelope for the material, yet the implant could be easily dissected from the subcutaneous tissue and could be removed en bloc without difficulty. Gore-Tex is a versatile material that seems to have a favorable future in facial plastic and reconstructive surgery. Clinical studies will define that potential more clearly.

Animals↗

PubMed1981

IgA antibody, antibody-dependent cellular cytotoxicity and prognosis in patients with nasopharyngeal carcinoma.

Immunoglobulin fractions containing antibodies to the Epstein-Barr virus (EBV) were isolated from different sera and tested in the antibody-dependent cellular cytotoxicity (ADCC) assay. All cytotoxic activity resided in the IgG fraction. IgA antibodies were not cytotoxic in this assay against cells expressing the EBV-induced membrane antigen complex. However, IgA antibodies were able to block the IgG-mediated ADCC reaction, indicating that the IgA and IgG antibodies recognized the same EVB-specific antigenic determinants. This was supported by results from radioimmune precipitation experiments. Our findings suggest that low ADCC titers previously identified in the sera of patients with nasopharyngeal carcinoma (NPC) who had a poor prognosis could be due to the blocking activity of IgA antibodies. The results further suggest that IgA antibodies are detrimental to the patient with this disease, if one assumes that ADCC functions in vivo in immunity to this tumor

Antibodies, Viral↗

PubMed1981

Chronic sinusitis.

Patients with chronic sinusitis often have a paucity of symptoms. However, patients may have exacerbations of acute sinusitis superimposed on the chronic disease, which may cause sinus pain, fever, and malaise. More often, though, patients seek evaluation for nasal stuffiness, hyposmia or cacosmia, and purulent nasal and postnasal secretions. Antibiotics seldom eradicate the disease; sinus drainage is the immediate goal of treatment. In maxillary sinusitis, construction of a nasoantral window is the best form of definitive treatment.

Aged↗

PubMed1981

Dissection of dizziness: with emphasis on labyrinthine vertigo.

The three most common types of vertiginous episodes area benign positional vertigo, postural vertigo, and endolymphatic hydrops. One of these conditions will be found in more than 90% of patients who present with vertigo as their main complaint. A clear understanding of the differences among these three entities will enable the physician not only to prescribe appropriate effective medical treatment but also to counsel and educate the patient about his or her particular condition.

Dizziness↗

PubMed1981

Managing ear infection in children.

Serous or suppurative middle ear effusion in children 2 years of age or older is common and is relatively easy to diagnose and treat. However, assessing and managing apparent ear infection in younger children--particularly infants--are more difficult tasks, and in many of these young patients the middle ear is found to be normal.

Child↗

PubMed1981

Tonsillectomy and adenoidectomy. Are there any indications?

Tonsillectomy and adenoidectomy have become quite controversial within the past two decades. Physicians disagree about the need for and benefits derived from these procedures, and well-designed studies to resolve the matter have been lacking. The authors describe conditions for which they believe each surgery is indicated.

Abscess↗

PubMed1981

The reliability of IgA antibody to Epstein-Barr virus (EBV) capsid antigen as a test for the diagnosis of nasopharyngeal carcinoma (NPC).

Since patients with nasopharyngeal carcinoma were first reported to have elevated levels of IgA antibody to Epstein-Barr virus (EBV) in their sera, workers in a number of countries have studied the possibility that this assay could be used in the diagnosis and monitoring of patients with this disease. In the United States, a collaborative project involving seven centers has been established to investigate the potential value of IgA antibody to EBV viral capsid antigen (VCA) as a clinical tool. In this report, we will summarize the results obtained from three studies: a comparison of EBV serology in three laboratories; a retrospective study of 37 nasopharyngeal carcinoma (NPC) patients and controls, and a prospective study of 126 NPC patients and 683 controls, including 149 patients with other malignancies involving the head and neck. The study of testing comparability in three laboratories demonstrated the feasibility of using this assay in a number of laboratories. The retrospective study confirmed the difference in IgA antibody titers between NPC patients and matched controls. The prospective study showed a relationship between IgA antibody titers and histopathology but not disease stage. IgA antibody titers were elevated more frequently in patients with nonkeratinizing or poorly differentiated types of NPC than for the well-differentiated squamous cell carcinomas. While IgA antibodies to EBV VCA appear to be of value in the early detection and diagnosis of NPC, it is possible that additional serologic tests for immunity to EBV, such as IgG antibody to VCA or early antigen (EA), will improve even further the clinical value of EBV serology in the management of NPC.

Antibodies, Viral↗

PubMed1980

Sarcomas of the larynx.

From 1949 to 1974, 17 patients with sarcomas of the larynx were treated at the Mayo Clinic. Histologically, the sarcomas were classified as fibrosarcoma (six tumors), chondrosarcoma (seven tumors), rhabdomyosarcoma (three tumors), and osteosarcoma (one tumor). Patients with chondrosarcomas tended to differ from patients with other sarcomas in respect to origin of the sarcoma and length of survival free of disease.

Adolescent↗

PubMed1980

Immunotherapeutic effect of cryosurgical tumor necrosis.

It is clear, then, that cryosurgery augments immunity that is specifically directed against the tumor in several murine tumor systems. Both cell-mediated and humoral immunity are involved. The degree of augmentation of immunity is greater than that following a period of tumor growth and cold-knife excision and that following electrocoagulation of tumor. The degree of tumor-specific immunity after cryosurgery is not sufficient to alter growth rates of recurrent tumors, however. Although immunity is not markedly potentiated, it is sufficiently augmented to be effective in protecting against small doses of tumor cells of up to 10(6) cells, and presumably in the presence of minimal residual disease. It is possible that immunity could be potentiated further by the injection of accessible tumors with a nonspecific immunoadjuvant one to five days before cryosurgery.

Animals↗

PubMed1980

Cryosurgery for the treatment of cancer.

Cryosurgery is that branch of cryobiology and surgery which deals with the therapeutic application of cold at profoundly low temperatures (those below 0 degrees C) for the purpose of destroying tissues in selected target sites. The freezing process induces coagulation necrosis and is confined to the tissues within the region of the probe application and the ice ball. The degree and extent of tissue destruction depend largely on the size of the ice ball and the temperatures within it. Various types of equipment and probes are commercially available for cryosurgery, but it was only after the development of reliable, versatile cryosurgical systems cooled by liquid nitrogen that numerous applications for cryosurgery were proposed, including therapy for cancer. In the treatment of cancer, clinical success with cryosurgery has led to the more wide-spread application of this modality in selected patients. Cryosurgery has been used for readily accessible lesions in specific anatomic areas, most frequently the skin and oral cavity. It is an attractive alternative to extirpative surgery, particularly in the head and neck, where removal of large portions of the mandible or maxilla are often required to control cancer. Therefore, it is not surprising that many of the pioneering efforts in the treatment of cancer have been conducted by otorhinolaryngologists. The full theoretic potential of cryotherapy was somewhat slow to be realized because many early endeavors were directed toward palliation, especially of accessible tumors of the skin and oral cavity, after failure of tumor control by radiation or surgery or both. This limited application during the early period of evaluation reflected a naturally timorous course that was taken by those who introduced the new modality into clinical practice. This period paralleled the development of new apparatus, early clinical trials, and the assessment of the clinical potential of cryosurgery in patients with incurable cancer--those whose conditions were deemed hopeless. Today, cryosurgery is selectively applied for the treatment of patients with tumors involving structures such as bone, oropharyngeal mucosa, temporal bone, skin, brain, retina, prostate, uterine cervix, and tracheobronchial tree. Although general guidelines for the application of cryosurgery to cancer can be gleaned from various clinical reports, the optimal conditions of freezing have not been specially defined. Animal experiments are necessary to study the variables methodically and in detail. The temporal and physical conditions for cryogenic necrosis of cancer require delineation so that cell death can be predictably and consistently reproduced. This is the thrust of this paper.

Adult↗

PubMed1980

Anti-EBV serologic tests for nasopharyngeal carcinoma.

Sixty-three serum specimens from American patients with nasopharyngeal carcinoma were examined for antibodies to antigens associated with Epstein-Barr virus (EBV) and compared with 98 specimens from patients with other head and neck cancers, 133 from patients with benign head and neck diseases, and 96 from healthy donors. The level of antibody titers to EBV-associated antigens was correlated with nasopharyngeal carcinoma. The anti-EBV profile of elevated antibody titers directed against viral capsid antigen and early antigen was seen in undifferentiated and nonkeratinizing tumors but usually not in squamous cell tumors. Titers tended to rise with large increases in total tumor burden caused by distant metastases, often before clinical evidence of metastases. At the time of diagnosis, antibody-dependent cellular cytotoxicity testing was performed on serum samples from 46 of the patients with nasopharyngeal carcinoma. Pretreatment titers were usually low in patients in whom recurrence developed and were high in most of the patients who had a good response to treatment and have remained free of recurrence.

Adolescent↗

PubMed1980

Transplantation of fresh allografts (homografts) of crushed and uncrushed cartilage and bone: a 1-year analysis in rabbits.

Fresh allografts (homografts) of cartilage and bone, crushed and uncrushed, were transplanted in 53 rabbits. Each material was implanted into the auricle and concomitantly into the subdermis of the face. Postoperative assessment was every 1 to 3 days; sacrifice was at 6 weeks, 6 months, and 1 year for microscopic evaluation. Uncrushed cartilage allografts remained viable, and no significant resorption occurred. Crushed cartilage was significantly resorbed by 6 weeks but changed little after that. Resorption of uncrushed bone was moderate and appeared to be ongoing. Total resorption by 1 year occurred in the absence of contact with perichondrium or periosteum. Crushed bone, like crushed cartilage, was largely resorbed. These data document the fact that uncrushed cartilage is superior to crushed cartilage, crushed bone, or uncrushed bone for fresh allograft transplantation in the rabbit and that uncrushed cartilage is probably superior to all other fresh allografts for use in the clinical setting.

Animals↗

PubMed1980

Malignant melanoma of the oral cavity: review of 10 cases.

Oral malignant melanoma is uncommon, comprising less than 1% of all malignant melanomas. Consequently, few cases have been reported from any one institution. We report 10 cases of malignant melanoma of the oral cavity seen at the Mayo Clinic between 1905 and 1979. The site of the primary tumor was the hard palate in 4 patients, the soft palate in 2 patients, the lower alveolus in 2 patients, and the upper alveolus and the retromolar trigone in 1 patient each. Eight of these tumors occurred in men, and 8 patients were older than 60 years of age. Presenting symptoms were a pigmented mass in 9 patients, pain in 5 patients, and bleeding in 3 patients. In 4 patients, the tumor occurred in an area of preexisting hyperpigmentation. The treatment of choice in this disease is surgery; it is the only form of therapy with curative potential. Radiation therapy produced tumor regression in one patient in whom the tumor was considered inoperable, although there was no effect on eventual survival. Chemotherapy was ineffective in producing tumor regression. The prognosis of patients who have malignant melanoma of the oral cavity is dismal; the median survival time in this series was 16 months after diagnosis. Early diagnosis of pigmented lesions in the mouth and adequate tumor resection may improve the prognosis in this disease; however, once the tumor recurs, there is essentially no possibility of prolonged survival.

Adult↗

PubMed1979

Autografts of uncrushed and crushed bone and cartilage. Experimental observations and clinical implications.

This study evaluated autografts of bone and cartilage, uncrushed and crushed, in the perichondrial space of the ear and subcutaneously in the paraspinal region in rabbits six weeks and six months after transplantation. The results support the belief that in a clinical setting it is important to preserve perichondrium because it facilitates growth of new cartilage. This study suggests that when autogenous tissue is to be used for subcutaneous augmentation, it is best to use crushed or uncrushed cartilage or uncrushed bone because they remain viable. In the perichondrial space, crushed and uncrushed cartilage grafts not only remain viable but also induce growth of new cartilage and bone. Autogenous crushed bone does not survive in the perichondrial space of the rabbit ear.

Animals↗

PubMed1979

Implants of Supramid, Proplast, Plasti-Pore, and Silastic.

Four types of synthetic materials were implanted in 54 rabbits: Supramid, Proplast, Plasti-Pore, and Silastic. Each material was implanted into the auricle and concomitantly into the subdermis of the face. Postoperative assessment was every one to three days, while killing was done at six weeks, six months, and one year postoperatively for microscopic evaluation. Supramid mesh contains black pigment, which became incorporated within the histiocytes and giant cells around the implanted mesh by six weeks; at one year, the soft tissues were pigmented microscopically. Proplast was not extruded despite an intense and persistent histiocytic and giant-cell reaction; its black color constituted a major drawback for implantation beneath thin skin. The Plasti-Pore used in these studies was rigid and somewhat difficult to sculpture, and it induced a persistent but minor cellular reaction. Silastic was easily displaced.

Animals↗

PubMed1979

Immunotherapeutic effect of tumor necrosis after cryosurgery, electrocoagulation, and ligation.

Tumor necrosis in situ by cryosurgery, electrocoagulation, or ligation generally induces or augments some increase in tumor-specific transplantation immunity (TSTI) as compared with excision. Excision of the tumor 24 hours after it has been rendered ischemic by either ligation or cryosurgery seems to produce TSTI that is significantly greater than that after excision of viable tumor without prior ligation or cryosurgery; the degree of this immunity is similar to that seen after the tumor is left in situ indefinitely after treatment. These data suggest that most of the immunization following tumor necrosis in situ occurs within 24 hours of treatment. The experimental findings support the clinical reports of putative immunologic potentiation after tumor necrosis in situ.

Animals↗