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Biomedical subjects

H M Hayes

Publications and source records attributed to H M Hayes.

At least 19 recordsLinked to original sources
PubMed2006

Late humoral rejection in a cardiac transplant recipient treated with the anti-CD20 monoclonal antibody rituximab.

Humoral or vascular rejection results from a B cell-mediated production of immunoglobulin (Ig) G antibody against a transplanted organ, producing immune complex deposition on the vascular endothelium, activation of the complement cascade, generation of endothelial dysfunction, and regional ischemic injury. Antibody-mediated rejection, which may be accompanied by hemodynamic compromise, is associated with reduced long-term graft survival. Patients believed to be at an increased risk of developing humoral rejection include women, particularly those with high levels of panel reactive antibodies, cytomegalovirus seropositivity, and positive cross matches, and subjects with prior sensitization to OKT3. Treatment options for humoral rejection include plasmapheresis to lower the circulating immunoglobulin levels followed by high-dose cyclophosphamide to reduce the B-cell population. Other modalities include total lymphoid irradiation, photophoresis, splenectomy, and, for treatment failures, retransplantation. Rituximab is a chimeric humanized monoclonal antibody directed against the pan B-cell surface molecule, CD20. It is approved for the treatment of low-grade B-cell non-Hodgkin's lymphoma. It has also been used successfully for the treatment of posttransplant B-cell lymphoproliferative disease. We report a case of late humoral rejection successfully treated with rituximab.

Antibodies, Monoclonal↗
PubMed2001

Comparability of national death index plus and standard procedures for determining causes of death in epidemiologic studies.

PURPOSE: To determine whether causes of death obtained through National Death Index (NDI) Plus are comparable to those obtained by requesting death certificates from state vital statistics offices and having deaths coded by contractor nosologists. METHODS: The authors compared underlying cause of death codes obtained from NDI Plus with those assigned by contractor nosologists for a sample of 250 known decedents. RESULTS: The underlying cause of death codes differed for 18 (7%) of 249 successful matches. Independent coding by an expert National Center for Health Statistics (NCHS) nosologist trainer revealed that seven of these had an NDI Plus code that matched the code provided by the NCHS nosologist and a contractor nosologist code that did not match the NCHS nosologist code, seven had a contractor nosologist code that matched the NCHS nosologist code and an NDI Plus code that did not match the NCHS nosologist code, and four had both an NDI Plus and a contractor nosologist code that did not match the NCHS nosologist code. The level of disagreement with the NCHS nosologist and the organ systems involved were similar for NDI Plus and the contractor nosologist. CONCLUSIONS: The authors report that NDI Plus provides comparable information within a substantially shorter time period for most states and, for known decedents, at about half the cost of standard procedures.

Cause of Death↗
PubMed1995

On the association between canine malignant lymphoma and opportunity for exposure to 2,4-dichlorophenoxyacetic acid.

In response to criticisms raised regarding a case-control study of canine malignant lymphoma, the results of several ancillary analyses are reported. The case-control study demonstrated a significant association between risk for canine malignant lymphoma and the opportunity for exposure to 2,4-dichlorophenoxyacetic acid herbicides. It is demonstrated that risk estimates do not vary by type of control group (i.e., tumor control or nontumor control group), by method of response (i.e., self-administered or telephone interview), or by geographic area. Questions related to the potential for referral bias, supposed inconsistencies in subject responses regarding frequency of herbicide use, and ambiguities regarding exposure classification are also examined.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1995

A cohort study of the effects of Vietnam service on testicular pathology of U.S. military working dogs.

Using histopathologic diagnoses made on necropsy material from 3,024 military working dogs (MWDs) who died from 1968 to 1973, we analyzed the effect of military service in the Republic of Vietnam on testicular pathology. Among 1,048 MWDs that died in Vietnam and had no reported developmental risk factors for testicular disease, significant excesses of testicular hemorrhage, epididymitis/orchitis, sperm granuloma, testicular degeneration, and seminoma were evident. Among 126 MWDs with prior Vietnam service who died at other duty stations outside Vietnam from 1968 to 1973, significant excesses of testicular degeneration and seminoma were likewise evident. Among 136 MWDs with prior Vietnam service that later died from 1974 to 1980, seminoma continued to be diagnosed in significant excess. In each instance, the odds ratio for the association between Vietnam service and seminoma was 2.0 or greater. Analysis of ever service by Corps Tactical Zones showed significant excesses of seminoma with each Corps area of service compared to Vietnam-era MWDs, but risk was highest in I Corps, particularly at Da Nang Port and Da Nang Air Base. This finding with respect to I Corps is consistent with certain human studies in Vietnam veterans and points to the need for further investigation of possible environmental exposures, particularly those associated to a greater extent with service in I Corps.

Animals↗
PubMed1994

U.S. military working dogs with Vietnam service: definition and characteristics of the cohort.

We verified and corrected inaccuracies in descriptive profile information on military working dogs (MWDs) that died from 1965 to 1980 and were reported in the Armed Forces Institute of Pathology Registry of Veterinary Pathology. Using other available military records, we determined which dogs served in Vietnam. Identified were 3,895 MWDs with a unique identity tattoo that served in Vietnam, of which 2,389 served exclusively with U.S. military forces and died in Vietnam. Another 479 Vietnam veteran MWDs completed their service elsewhere. This overall effort resulted in signalment corrections, generally age at death, in 21% of the Registry MWD accessions during the study period. The improved definition and characterization of the Vietnam cohort will lead to greater precision in epidemiologic investigations of the health effects from the Vietnam experience in U.S. military working dogs.

Animals↗
PubMed1991

Case-control study of canine malignant lymphoma: positive association with dog owner's use of 2,4-dichlorophenoxyacetic acid herbicides.

A hospital-based case-control study of companion dogs examined the risk of developing canine malignant lymphoma associated with the use of chemicals in and about the home. Information from a self-administered owner questionnaire and/or a telephone interview of about 491 cases, 466 nontumor controls, and 479 tumor controls indicated that owners in households with dogs that developed malignant lymphoma applied 2,4-dichlorophenoxyacetic acid (2,4-D) herbicides to their lawn and/or employed commercial lawn care companies to treat their yard significantly more frequently than control owners (odds ratio = 1.3). In addition, the risk of canine malignant lymphoma rose to a twofold excess with four or more yearly owner applications of 2,4-D. The findings in this study are consistent with occupational studies in humans, which have reported modest associations between agricultural exposure to 2,4-D and increased risk of non-Hodgkin's lymphoma, the histology and epidemiology of which are similar to those of canine malignant lymphoma. The present study suggests that human health implications of 2,4-D exposure in the home environment should receive further investigation.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1990

Excess of seminomas observed in Vietnam service U.S. military working dogs.

During the Vietnam War, US military working dogs served with their companion dog handlers in close proximity, sharing common exposures to war-related activity, many zoonotic infectious agents, chemical pesticides, phenoxy herbicides, and extensive use of therapeutic drugs. To gain insight into the effects of the Vietnam experience, we investigated the occurrence of neoplasms in military working dogs based on standard necropsy examination by the Armed Forces Institute of Pathology. We observed that these dogs experienced significant elevated risks for testicular seminoma and, independently, testicular dysfunction. Experimental evidence shows testicular dysfunction and impaired spermatogenesis in laboratory animals exposed to phenoxy herbicides, dioxin, or tetracycline, and antibiotic used extensively in military working dogs in Vietnam. Because an unexplained significant decrease in sperm quality in Vietnam veterans has been observed by the Centers for Disease Control, further research is warranted if we are to clarify military service in Vietnam as a risk factor for testicular dysfunction. The testis should be made a priority site in the study of Vietnam experience-related cancers.

Animals↗
PubMed1987

Effects of ear type and weather on the hospital prevalence of canine otitis externa.

A retrospective study of 8975 dogs seen at 15 university veterinary medical teaching hospitals in North America (1975 to 1978) found that dogs with pendulous ears and heavy ear canal hair had significantly (P less than 0.01) more otitis externa than dogs with other ear types. Dogs with erect ears, regardless of the amount of ear canal hair, had less risk (P less than 0.01) of the disease than mongrel dogs. Direct evidence is available for the first time showing that monthly variations in ambient temperature, rainfall and relative humidity explain, to a large extent, the monthly variations in the hospital prevalence of canine otitis externa in different geographic regions.

Animals↗
PubMed1986

Hospital incidence of hypospadias in dogs in North America.

A review of medical records from 17 North American university veterinary medical teaching hospitals identified 66 dogs with hypospadias. Males predominated (15:1) and cryptorchidism was the most commonly diagnosed second anomaly, often associated with intersexuality. Fifteen cases, diagnosed at 10 different university hospitals, were Boston terriers, strongly suggesting that this breed has a familial predisposition for hypospadias. Male mongrels, as a group, were seen in approximately the same proportion as their representation in the hospital population, suggesting other components in the aetiology of the condition. If maternal histories are obtained as new cases are identified, a better understanding of the factors associated with the aetiology of the condition may be possible.

Animals↗
PubMed1986

Epidemiological features of 5009 cases of equine cryptorchism.

Data from 16 North American veterinary university teaching facilities, 5009 cryptorchid horses, were analysed using relative risk methodology. In five breeds (Thoroughbred, Standardbred, Morgan, Tennessee Walking horse and Arabian), cryptorchism was diagnosed significantly (P less than 0.05) less frequently than expected by their representation in the hospital population. Three breeds, (Percheron, American Saddle horse and American Quarterhorse), plus ponies (as a group) and crossbred horses were significantly over-represented within the series. The over-representation of Quarter-horses was evident at each veterinary teaching facility. Other developmental defects and testicular tumours diagnosed in cryptorchid horses were presented. Analysis of the frequency of diagnosis of second anomalies among cryptorchids showed testicular hypoplasia to occur significantly more often, and inguinal and umbilical hernias less often, than expected (P less than 0.05).

Animals↗
PubMed1985

Canine cryptorchism and subsequent testicular neoplasia: case-control study with epidemiologic update.

A retrospective study of 2,912 cryptorchid dogs identified 14 breeds with significantly high risk. Among six distinct closely interrelated breed groups (e.g., toy, miniature, and standard poodles), the risk in the smaller breed was always greater than that in the larger relative, suggesting that genetically influenced maldescent could be, in part, related to physical size or the rate of growth of the involved structures. Testicular tumors were diagnosed in 5.7% of the cryptorchid dogs; half had only Sertoli cell tumors, one-third had only seminomas. The relative risk for Sertoli cell tumor or seminoma was not directly related to a familial risk for cryptorchism. Using the health experience of a control population composed of male dogs with anal sac disease (N = 4,184), there is an estimated relative risk of 9.2 in cryptorchid dogs to develop a testis tumor (95% confidence interval, 5.9-14.3) and 4.2 in dogs with inguinal hernia (95% confidence interval, 1.8-9.5). Considering that the anatomical development of the genital tract, testis descent, and tunic relationships in dog are very similar to that in man, and that the associations of cryptorchism and inguinal hernia with testis neoplasms are also similar, the dog should be an excellent model system to further investigate the causes of human cryptorchism.

Animals↗
PubMed1983

Juvenile renal disease in Doberman Pinscher dogs.

Renal failure was diagnosed in 22 young Doberman Pinscher dogs. The clinical findings were anorexia, weight loss, vomiting, lethargy, polydipsia, polyuria, and dehydration. Laboratory findings were azotemia, hyperphosphatemia, lymphopenia, nonregenerative anemia, hypercholesterolemia, and proteinuria. The kidneys were characterized pathologically by glomerular sclerosis, cystic glomerular atrophy, tubular dilatation, tubular atrophy, mononuclear interstitial inflammation, interstitial fibrosis, interstitial mineralization, and hyperplasia of the collecting duct epithelium.

Age Factors↗
PubMed1983

Canine biliary carcinoma: epidemiological comparisons with man.

A retrospective study of abstracted data representing 1.1 million hospital examinations of dogs at veterinary university teaching facilities identified 77 with bile duct carcinoma. Using the hospital population, based on patient years at risk, as the expected frequency of particular zoographic characteristics, there was a suggestion of a familial (breed) predisposition in Labrador retrievers and limited evidence of a sex differential. Because mongrel dogs displayed about the same frequency of bile duct cancer as all breeds combined, other causal factors, besides genetics, are implied. A possible association was detected between canine cholangiocarcinoma and host infection by canine hookworms and/or whipworms. Human infection from hookworms (Necator americanus) and whipworms (Trichuris trichiura) is common in the southern rural areas of the U.S.A. (e.g. Appalachia), and tropical and sub-tropical countries of Africa, Central and South America, where there have been unexplained high rates reported for human biliary cancer. It is possible that the presence of these blood-letting nematodes, like a number of other parasites (ascarids, flukes and protozoa), may be related to the occurrence of human cholangiocarcinoma.

Animals↗