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Biomedical subjects

H C Hoover

Publications and source records attributed to H C Hoover.

At least 37 records · Page 2Linked to original sources
PubMed1989

Efficacy of adjuvant interleukin-2 after excision of BALB/c fibrosarcomas.

Interleukin-2 (IL-2) has been evaluated as a therapeutic agent in a number of metastatic tumor systems. We hypothesized that administration of IL-2 might be more effective as adjuvant therapy in the presence of a greatly diminished tumor burden after tumor excision. In this BALB/c methylcholanthrene-induced sarcoma model, excision of 0.3 to 0.4 gm tumors results in local recurrence rates of 50% to 70%. Administration of human recombinant IL-2 at a dose of 50,000 units three times daily for 5 days to animals with established tumors resulted in 100% mortality. IL-2 administration started at the time of tumor implantation had no effect on tumor growth. Mice receiving adjuvant IL-2 at 50,000 units per dose after surgery had prolonged survival compared with controls (79% vs. 32%, p = 0.007); addition of concanavalin A-activated lymphocytes to IL-2 therapy did not enhance survival over that with IL-2 alone. Therapy with lower doses of adjuvant IL-2 on the same treatment schedule resulted in improved survival at doses as low as 5000 units (86% vs. 51% for controls, p = 0.003). Although the exact mechanism of this therapeutic effect has not been determined, IL-2 may act by a variety of mechanisms, including a decrease in the immunosuppressive effects of anesthesia and surgery, the generation of endogenous IL-2-activated effector cells, and the augmentation of efflux of circulating effector cells from peripheral blood into the site of surgically induced inflammation.

Adjuvants, Immunologic↗
PubMed1987

Adenosquamous carcinoma of the colon presenting with hypercalcemia.

A rare adenosquamous carcinoma of the colon occurred in a 41-year-old patient. Its presentation with hypercalcemia, in the absence of osseous metastases, has not been described previously. The hypercalcemia in this case was due to the elaboration of a parathyroid hormone-like substance by the tumor. The general characteristics of primary adenosquamous and squamous cell carcinomas of the colon are presented. These tumors present with advanced disease, in younger patients, and follow a highly aggressive course, as compared with adenocarcinomas of the colon. The cause of the malignancies, in the light of current theories regarding their genesis, is discussed.

Adenocarcinoma↗
PubMed1986

Squamous cell carcinoma in congenital ichthyosis with deafness and keratitis. A case report and review of the literature.

The first case of invasive squamous cell carcinoma (SCC) arising in the skin of a patient afflicted with keratitis, ichthyosis, and deafness (KID) syndrome is reported. A 35-year-old man, diagnosed as having KID syndrome in early childhood, developed bilateral fungating lesions on his feet. The entire left foot became involved with a multinodular fungating mass which proved to harbor a SCC, necessitating a left below-knee amputation. Although rare, KID syndrome can be associated with SCC of the skin.

Adult↗
PubMed1985

Prospectively randomized trial of adjuvant active-specific immunotherapy for human colorectal cancer.

Over the last four years a guinea pig model of active-specific immunotherapy (ASI) with a syngeneic tumor cell:bacillus calmette-Guerin (BCG) vaccine was translated into a prospectively randomized, controlled clinical trial in patients with colorectal cancer. Primary tumors from patients undergoing standard surgical resection were dissociated enzymatically and cryopreserved by techniques that maintain cell viability. Patients with transmural extension of tumor or nodal metastases were randomized into groups treated by resection alone (control) or resection plus ASI. With a mean follow-up of 28 months (range, 14-24), only 3 of 20 treatment patients had recurrences and none have died, whereas 9 of 20 control patients had recurrences and 4 died. These differences are statistically significant and are sufficiently encouraging to warrant expansion of these studies into other research centers.

Adult↗
PubMed1985

Generation of tumor cell-reactive human monoclonal antibodies using peripheral blood lymphocytes from actively immunized colorectal carcinoma patients.

The use of human monoclonal antibodies (MCA) in the detection and treatment of human cancer has been limited by the apparent scarcity of MCA to tumor cell surface antigens. Using peripheral blood lymphocytes from autologous tumor-immunized patients, we isolated 36 MCA that react to sections of colorectal carcinoma. Twenty of these human MCA appear to be directed against cell surface antigens. Two-thirds of the human MCA-producing cell lines were diploid human B-cells rather than human-mouse heterohybridomas. Direct antibody-binding assays performed with the MCA indicated that they recognized antigenic determinants preferentially expressed on tumor cells. Experiments with paired specimens of air-dried, dissociated colon tumor cells and normal colonic mucosa cells suggested that the MCA bound significantly more to the cell surfaces of tumor cells than to the surfaces of normal colonic mucosa cells. Similarly, tests with a panel of cryostat sections of paired colon tumor and normal colonic mucosa showed that MCA bound to the tumor cells and not to the normal colonic mucosa. None of the MCA bound to cells from frozen sections of normal breast, stomach, liver, skeletal muscle, or skin. Furthermore, the human MCA did not react with carcinoembryonic antigen and human erythrocyte antigens as measured by various techniques. Our data also demonstrated that these transformed B-cells and hybridomas were stable producers of human MCA. Thus, our studies show that these tumor-specific human MCA may have the specificity and stability necessary for in vivo evaluation of their use in the detection and treatment of cancer.

Animals↗
PubMed1984

Desmoid tumors in Gardner syndrome: use of computed tomography.

Desmoid tumors are known to be associated with Gardner syndrome and, when located in the mesentery, can contribute to morbidity and mortality. Computed tomography (CT) was used to evaluate six patients with Gardner syndrome who, after colectomy, complained either of abdominal pain or of palpable masses. In five patients, desmoids of the mesentery, abdominal wall, and paraspinous muscles were diagnosed; four of these were later proven surgically. The sixth case, with both CT and subsequent surgery negative for desmoid lesions, is included to illustrate the ability of CT to replace exploratory surgery in certain instances. CT provides a relatively noninvasive means of assessing and following patients with Gardner syndrome after colectomy and delaying or preventing further surgery or, if necessary, providing a surgical "road map" to optimize unavoidable procedures.

Adult↗
PubMed1984

Delayed cutaneous hypersensitivity to autologous tumor cells in colorectal cancer patients immunized with an autologous tumor cell: Bacillus Calmette-Guérin vaccine.

The principles and procedures of active specific immunotherapy developed from studies with the inbred guinea pig hepatocarcinoma model were used as the basis of a randomized, controlled prospective trial of active specific immunotherapy of colorectal cancer patients. The goal was to determine whether colorectal cancer patients treated with vaccines made of autologous tumor cells plus Bacillus Calmette-Guérin as adjuvant would have an increased reaction to their autologous tumor cells as measured by delayed-type cutaneous hypersensitivity (DCH) responses. Our results demonstrate that the active specific immunotherapy significantly increased the DCH responses to autologous tumor cells in 16 of 24 patients (67%). The DCH response of immunized patients to autologous normal mucosa, used as a normal tissue control, did not increase significantly. Furthermore, no significant DCH responses against autologous tumor or mucosa cells were detected in a group of nonimmunized control patients. The induced DCH responses were not correlated with other factors, such as the presence of bacteria in the cell preparation or the protein concentration of the cell preparations. The qualitative and quantitative differences in DCH responses to tumor cells and to normal mucosa cells suggest that the immunizations are targeted mainly to tumor-associated antigens with tissue-associated antigens playing a secondary role.

BCG Vaccine↗
PubMed1983

Endorectal pull-through operation in adults after colectomy and excision of rectal mucosa.

Ileal endorectal pull-through can be performed in adults after abdominal colectomy and excision of rectal mucosa. The procedure requires a painstaking dissection of the mucous membrane of the rectum to ensure cure of the polyposis or ulcerative colitis for which it is carried out. Some cases of ulcerative colitis are inappropriate for this dissection, and Crohn's disease prohibits the use of this operation. Fifteen operations in adults are described herein. Certain technical maneuvers have been of help to us and these are described. We have favored a diverting ileostomy maintained for 3 months. A pouch, positioned in the rectum, has hastened the return toward normal control. Sphincter control and responses have been uniformly good. Dilatations and sphincter exercises are routinely employed. Strictures are not rare but are amenable to correction by digital stretching.

Adolescent↗
PubMed1982

Active specific immunotherapy of established micrometastases with BCG plus tumor cell vaccines: effective treatment of BCG side effects with isoniazid.

Intradermal vaccinations with Bacillus Calmette-Guérin (BCG) and viable but nontumorigenic syngeneic hepatocarcinoma cell vaccines were used successfully to treat micrometastatic disease experimentally induced in inbred guinea pigs at 100 times the minimal lethal dose. Several complications have been associated with the use of viable BCG organisms in the treatment of cancer patients and, in this animal model, intradermal administration of BCG uniformly results in severe ulceration and eschar formation at the injection sites leading to secondary microbial invasion and regional lymphadenopathy. We now report the use of isoniazid (Nydrazid) as part of an active specific immunization regimen. Incorporation of isoniazid into the immunization procedure for two weeks alleviates or reduces the side effects of BCG infection. Moreover, with proper consideration of BCG dosage, isoniazid does not impair the efficacy of the BCG plus tumor cell vaccines.

Animals↗
PubMed1982

Clinical trials of amniotic membranes in burn wound care.

Four test conditions of increasing complexity were used to evaluate the clinical efficacy of amniotic membranes as biologic dressings on donor sites and burn wounds in children. These were the clean-skin donor-site wound, the uncontaminated shallow partial-thickness burn wound, the bed of freshly excised full-thickness wounds, and the granulating surface of colonized burn wounds. The rate of epithelialization under amniotic membranes was the same as that under 5% scarlet red ointment or 0.5% silver nitrate solution dressings. Preservation of a healthy excised wound bed and maintenance of a low bacterial count in contaminated wounds paralleled the experience with human allograft dressings despite technical difficulties and the absence of vascularization of amniotic membrane and its fragile structure. Tentative conclusions are drawn as to the mechanisms by which biologic dressings exert their beneficial effects.

Bandages↗
PubMed1981

Immunological studies of ribonuclease C from human urine.

Antiserum to human urinary RNase C [ribonuclease (pancreatic), EC 3.1.27.5], developed in rabbits, was used to characterize this enzyme through studies of inhibition of RNase C-catalyzed poly(C) hydrolysis and of competition in a RIA. By either assay, the antiserum failed to cross react with human urinary RNase U (EC 3.1.27.-) or bovine pancreatic RNase A (EC 3.1.27.5). RNase C is immunologically identical to the poly(C)-active RNase in various human sera, including samples obtained from normal individuals, patients with pancreatic carcinoma, pancreatitis, or other malignant and nonmalignant diseases. This conclusion is based on the finding of superimposable antibody dose-inhibition curves for poly(C) hydrolysis and parallel competition RIA curves for RNase C and the various sera. There was a positive correlation (r = 0.73; p less than 0.001) between concentrations of RNase C as determined by poly(C) hydrolysis and competition RIA in serum samples from 102 patients. Therefore, the latter technique provides al alternative method for measuring RNase C in sera.

Antigen-Antibody Complex↗
PubMed1980

Nutritional benefits of immediate postoperative jejunal feeding of an elemental diet.

Positive nitrogen balance and preservation of body weight and total proteins were demonstrated in 26 patients undergoing extensive upper gastrointestinal operations who were randomized to receive elemental diet by a needle catheter jejunostomy. Infusions were started immediately after operation and continued for 10 days. In 26 patients receiving enteral feedings and 22 intravenous control patients, mean cumulative 10 day nitrogen balance was +11.7 +/- 5.4 and -44.7 +/- 6.5 g, respectively (p = 0.0001). Enterally fed patients lost only 0.02 +/- 0.5 kg of weight compared with 3.8 +/- 0.3 kg in control patients. The only complications were diarrhea in 34 percent of the study patients and one broken catheter. It is probable that the nitrogen and body weight preservation provided by enteral hyperalimentation equals or exceeds that demonstrated for total parenteral nutrition in postoperative patients.

Adult↗
PubMed1980

Femoral hernia with strangulated Meckel's diverticulum (Littre's hernia).

An unusual complication of a Meckel's diverticulum, a strangulated Littre's femoral hernia, is presented. The incidence and complications of Meckel's diverticulum are discussed. It is emphasized that most complications occur before age 30. Thus in an adult an incidentally discovered Meckel's diverticulum should not be resected.

Carcinoid Tumor↗