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Biomedical subjects

L Hoover

Publications and source records attributed to L Hoover.

27 records · Page 2Linked to original sources
PubMed1986

Prefabricated ossicular homografts in middle ear reconstructions.

This paper is a review of 132 cases of ossicular reconstruction utilizing prefabricated homografts by clinical staff members of the UCLA Division of Head and Neck Surgery (specializing in ear surgery) in their private practice over the past decade. Another 20 cases completed over the past 2 1/2 years in the UCLA teaching programme are also reviewed. Although ossicular homografts have been used for some time in middle ear reconstruction, this report presents the innovation of prefabricating homografts into specific shapes that lend themselves appropriately to reconstruction problems. In such an ossicular bank, a variety of different shapes, in a number of sizes, is maintained for quick selection. This greatly decreases operating room time and, in addition, provides an effective method for ossicular reconstruction that has already been applied to a resident training programme. The cases in this review can be divided into 3 basic categories: (1) mastoidectomy ossicular reconstruction; (2) exploratory tympanotomy with reconstruction; (3) stapedectomy. This study indicates that ossicular homografts are very well tolerated in their new transplanted positions. Our very low extrusion rate, extremely rare evidence of absorption, and lack of foreign body reaction to these ossicles coincides with the experience of others. This is an advantage over plastic prostheses. In addition to pre- and postoperative air conduction level data, analysis of changes in bone conduction and speech discrimination scores are also presented to evaluate possible neurosensory damage related to manipulation in placing these ossicles.

Adult↗
PubMed1986

Larynx and hypopharynx: MR imaging with surface coils.

Forty patients with disorders of the larynx or hypopharynx were studied with magnetic resonance (MR) imaging. Axial, coronal, and sagittal sections, 4 mm thick, were obtained. Twenty-eight of the patients underwent computed tomography (CT) scanning; 17 underwent surgery, and specimens were obtained for organ sectioning. Correlation was made between these three studies as well as with clinical history, physical examination, and endoscopic photography. In 13 patients who underwent all three studies, the depiction of cartilage invasion, adenopathy, and intraorgan and extraorgan spread of disease was compared. MR consistently showed superior soft-tissue definition and extent of disease compared with CT. Neither CT nor MR was able to depict histologic detail or microscopic spread of disease. Both studies were also less effective in the postoperative or postirradiated neck. The use of direct coronal and sagittal imaging planes on MR allowed the visualization of intrinsic laryngeal musculature, which was important in the recognition of subtle tumor extension. For these reasons, surface coil MR imaging is currently the imaging study of choice at our institution for disorders of the larynx and hypopharynx.

Carcinoma, Squamous Cell↗
PubMed1985

Cervical mycobacterial lymphadenitis. Medical vs surgical management.

After years in its decrease, cervical mycobacterial adenitis is once again an increasing problem in Los Angeles County. We reviewed 54 cases of cervical lymphadenopathies treated over ten years. Twenty-five (46%) of these patients were found to have mycobacterial cervical lymphadenitis. Medical approaches often failed to conclusively diagnose this disease. In our series, none of the patients with cervical adenopathies (36%) treated only medically regressed, even after an average time of 18 months of antituberculosis drug treatment. The treatment of choice seems to be surgical excision and long-term antituberculosis drugs. Surgery provides a rapid tissue diagnosis and confirms the bacterial type, including atypical mycobacterium. This approach is simple, shortens hospitalization, is cost-effective, and carries a low morbidity.

Adolescent↗
PubMed1984

Use of the MMPI to identify subtypes of delinquent adolescents.

Assessed the utility of the MMPI to identify and distinguish among subtypes of delinquent adolescents (N = 50). Behavior ratings were used as the criterion of classification into three delinquent subtypes--conduct problem, anxious-withdrawn, and a group with neither of those features. Only the Hs scale differed significantly between the first two groups. Results were disappointing in that they failed to support a previous study that had found differences, but that had used less rigorous classification criteria.

Adolescent↗
PubMed1981

Differentiation of pyriform sinus cancer from supraglottic laryngeal cancer by computed tomography.

Nine pyriform sinus tumors and 16 supraglottic laryngeal lesions were studied by computed tomography. The pyriform sinus tumors had a much higher incidence of thyroid cartilage invasion (five of nine patients) and involved the posterolateral margins of the cartilage. Only two of 16 supraglottic tumors reached the thyroid cartilage, involving the midline or more inferior margins. The supraglottic tumors grew in a circumferential pattern, and when the pre-epiglottic space was involved, extension was bilateral. Lesions of the pyriform sinus more frequently showed unilateral involvement. Lymph node metastases were seen in an approximately equal proportion of patients in the two groups, and they correlated more with the size of the primary tumor than with its site of origin. Posteroinferior invasion of the space between the thyroid and cricoid cartilage was seen only with pyriform sinus lesions.

Carcinoma, Squamous Cell↗
PubMed1975

A classification of transplantable tumors in Nb rats controlled by estrogen from dormancy to autonomy.

Transplantable tumor lines were previously established from a variety of estrogen-induced tumors in Nb rats, including tumors of the adrenal cervix, salivary gland, and pancreas, a lymphoma, and a liposarcoma. Spontaneous tumors, however, were found to arise in untreated females and showed the same characteristics. Tumor growth was dependent upon or influenced by estrogen when assessed in estrogenized and unconditioned hosts. Intermitten estrogenization was effective, but tumor growth took place more slowly. The type of response observed led to a new classification of five types of hormone-responsive tumors including tumors inhibited by estrogen. Estrogen-dependent tumor cells might remain dormant indefinitely and not grow in unconditioned animals until stimulated to grow by estrogen. The growth rate of hormone-dependent adrenal carcinomas was related to the amount of estrogen. Tumor growth started more rapidly in the presence of low estrogen dose levels in old rats used as hosts than it did in young rats. Breast carcinomas required the largest amount of estrogen for growth, whereas ovarian thecomas would grow in normal females but not in males. The growth rate in conditioned hosts of most transplanted tumors (some have maintained hormone dependency over 10 years) increased over successive generations. Progression, however, towards a more autonomous state after repeated transplantations was remarkably slow, and a sudden change to autonomy was rarely noted. In contrast, transplants of 9,12-dimethylbenz(a)anthracene-induced mammary carcinomas progressed rapidly to autonomy. Fould's concept of progression (2, 3) has been discussed but the described classification of tumors under hormone influence apparently allows a more detailed analysis of definition of different types of progression.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Fine needle aspiration in the evaluation of testicular leukemic infiltration.

Prior to the era of effective therapy for acute leukemia, a finding of occult testicular involvement at autopsy was not uncommon. With the advent of effective induction of remission, clinically evident testicular infiltration has been seen as a manifestation of relapse. A case is reported demonstrating the use of fine needle aspiration along with frozen section in the evaluation of testicular involvement as a manifestation of leukemic relapse.

Adult↗