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Biomedical subjects

D Kay

Publications and source records attributed to D Kay.

At least 19 recordsLinked to original sources
PubMed1992

Health effects of white-water canoeing.

There is little quantitative information on the relation between water quality and disease attack rates after recreational activities in fresh water. We conducted a prospective cohort study to measure the health effects of white-water and slalom canoeing in two channels with different degrees of microbial contamination. Site A, fed by a lowland river, showed high enterovirus concentrations (arithmetic mean 198 pfu per 10 litre and moderate faecal coliform concentrations (geometric mean 285/dl); at site B, from an upland impoundment, all samples were free of enteroviruses and the geometric mean faecal coliform concentration was 22/dl. Between 5 and 7 days after exposure canoeists using site A had significantly higher incidences of gastrointestinal and upper respiratory symptoms than canoeists using site B or non-exposed controls (spectators). Like seawater bathers, fresh-water canoeists can be made ill by sewage contamination. The hazard of fresh water may be best measured by counting of viruses rather than bacteria.

Adult↗
PubMed1991

Development of intrapancreatic transplantable model of pancreatic duct adenocarcinoma in Syrian golden hamsters.

Intrapancreatic and subcutaneous (SC) inoculation of cultured pancreatic cancer cells, derived from an induced primary pancreatic cancer in a Syrian hamster, resulted in tumor take in all recipient hamsters. The intrapancreatic allografts grew rapidly, were invasive, and metastasized into the lymph nodes and liver in 2 of 9 cases. In comparison, SC tumors grew relatively slower and formed a large encapsulated mass without invasion and metastases. Histologically, tumors of both sites showed fairly well-differentiated adenocarcinomas of ductal/ductular type resembling the induced primary cancer. Similar to the primary induced pancreatic cancers, tumor cells of both allografts expressed blood-group-related antigens, including A, B, H, Le(b), Le(y), Le(x), and tumor-associated antigen TAG-72. The tumor cells did not express Le(a), CA 19-9, 17-1A, or DU-PAN-2. The expression of these antigens was retained in the metastases and presented the same patterns of reactivity as the allografts. Thus intrapancreatic transplantation provides a rapid model for production of pancreatic cancer with morphologic similarities to human pancreatic cancer.

Adenocarcinoma↗
PubMed1989

Idiotypic cascades in cancer patients treated with monoclonal antibody CO17-1A.

We have previously shown that gastrointestinal cancer patients treated with monoclonal antibody CO17-1A (Ab1) developed anti-idiotypic antibodies (Ab2) to the Ab1. We now demonstrate that patients produce anti-anti-idiotypic antibodies (Ab3) to their autologous Ab2. Ab3 were demonstrated in culture supernatants of peripheral blood mononuclear cells from five Ab1-treated patients after stimulation of the cells with heterologous Ab2 that functionally mimicked the tumor antigen (Ag) defined by Ab1 and immunologically cross reacted with the patients' Ab2. Ab3 shared idiotopes with Ab1 and were Ab1-like in their binding specificities to tumor cells, Ag, and Ab2. Such antibodies were also elicited by stimulating cells with Ag. However, they were not produced by stimulating posttreatment mononuclear cells with control proteins or by stimulating pretreatment cells with either Ag or Ab2. Our results demonstrate idiotypic cascades in cancer patients treated with monoclonal antibody. Ag-specific Ab3 responses may underlie delayed clinical responses often observed in cancer patients treated with monoclonal antibodies of various specificities.

Adenocarcinoma↗
PubMed1989

Bronchopulmonary sequestration.

Bronchopulmonary sequestration is a rare lesion making up less than 10% of all congenital pulmonary malformations. The two classic types, extralobar and intralobar, can be distinguished by whether or not the sequestered pulmonary tissue is enclosed by a separate visceral pleural lining. A case of intralobar bronchopulmonary sequestration is presented. At present, aortography is necessary to establish the diagnosis, but other imaging modalities including computed tomography, ultrasound, and magnetic resonance imaging offer the potential for additional useful information.

Adult↗
PubMed1988

Plantar fasciitis. Mechanics and pathomechanics of treatment.

An excessive amount and/or a prolonged duration of pronation is the most common mechanical cause of structural strain resulting in plantar fasciitis. Temporary relief of pain can be achieved by customary antiinflammatory drugs or therapy; long-term relief is achieved by adequate remedy of the aggravating pronation factors. A semirigid, custom-molded orthosis reduces excessive plantar fascial strain by supporting the first metatarsal bone and by controlling calcaneal position when in conjunction with a firm posterior counter shoe. A clinical environment with physician and orthotist together allows ideal evaluation and treatment of patients.

Fasciitis↗
PubMed1988

Primary lymphoma of the central nervous system in children with acquired immunodeficiency syndrome.

Three children with acquired immunodeficiency syndrome and primary lymphoma of the CNS are described. All three children had clinical signs of focal mass lesions and progressive neurologic deficits. In one child the deterioration was extremely rapid. New lesions appeared on serial CT scans every few days, simulating an infectious process and leading to death within 3 weeks. Results of neuroradiologic studies in these patients demonstrated multicentric lesions that were often periventricular. On CT scans, the lesions were hyperdense before contrast and were enhanced with contrast medium. Double-dose delayed contrast CT scans and magnetic resonance imaging studies were more sensitive in indicating additional lesions. Histologically, all three tumors were B cell neoplasms; two lymphomas were large cell type, whereas one was small cell, noncleaved (Burkitt-like). Primary CNS lymphoma occurred with an incidence of 1/26 (4%) in our autopsy series and 3/100 (3%) of all pediatric cases of human immunodeficiency virus-type 1 infection, living and dead, that have been seen at the Children's Hospital of New Jersey. By comparison, opportunistic and reactivated latent CNS infections were less common in this same population and never appeared clinically as mass lesions. Therefore, in our experience, primary lymphoma is the most common cause of focal or multifocal mass lesions in the brains of children with acquired immunodeficiency syndrome. This tumor may be radiosensitive. In most cases, early biopsy is probably necessary to establish the diagnosis.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Pain in rheumatoid arthritis: relationship to demographic, medical, and psychological factors.

Our purpose was to investigate the relationship among demographic, medical, and psychological factors and self-reported pain in 135 patients with classic or definite rheumatoid arthritis (RA). Patients were examined using the systemic index, articular index, McGill Pain Questionnaire, Symptom Checklist-90-R, and a pain visual analogue scale. Multiple regression analyses found no significant relationships between pain and the medical variables. However, age, income, and selected psychological variables were significantly correlated with pain reports. The greatest pain management challenge occurred in patients who were middle-aged, living on limited incomes, and experiencing major stresses in everyday life. These high risk pain patients were also worry-prone and felt isolated and lacking in social support. Attention to these related psychosocial problems is recommended as an important pain management strategy in RA.

Arthritis, Rheumatoid↗
PubMed1987

A malaria protein exported into a new compartment within the host erythrocyte.

A Plasmodium falciparum protein which is exported into a new compartment in the host erythrocyte has been located. This protein, exp-1, has a variable region recognized by a monoclonal antibody. Naturally occurring mutants of this region have been characterized. All mutants studied so far have the same A----G transition abolishing the target for the antibody. The exp-1 gene has a complex structure containing two introns. It is highly conserved in five independent, genetically defined parasite lines, suggesting that exp-1 has an important function. We discuss the possible role of exp-1 in P. falciparum infections.

Amino Acid Sequence↗
PubMed1987

The head-tail linker protein of bacteriophage T5: genetic and immunological studies.

We investigated the properties of amber mutants of coliphage T5 defective in a late stage of phage assembly. The non-functional heads synthesized by mutants am25 or am158 were unable to combine with functional tails to produce viable phage particles. These mutants were shown to lack a single protein, designated the head-tail linker protein (HTLp), which was identified by polyacrylamide gel electrophoresis and Western blot analysis and had an Mr of 18,000. An extract containing the HTLp, when added to the HTLp-deficient heads, restored their ability to combine with functional tails.

Electrophoresis, Polyacrylamide Gel↗
PubMed1986

The characterization of a set of amber mutants of bacteriophage T5.

A collection of amber mutants of bacteriophage T5 was analysed using an in vivo complementation test and assigned to 21 complementation groups. The incomplete phage structures produced by T5 amber mutant infection of the non-permissive host were examined. The mutants were allocated to four phenotypic types, as defined by an in vitro complementation test: those which produced functional heads, H; those which produced functional tails, T; those which produced inactive heads and functional tails, HI + T; and those which did not synthesize either heads or tails, 0. Functional heads and inactive heads were indistinguishable in shape and size in the electron microscope. Four different patterns of DNA metabolism were observed when different amber mutants were grown under non-permissive conditions. They were the wild-type pattern (D+) in which host DNA degradation was followed by synthesis of phage DNA, host DNA degradation without phage DNA synthesis (D0), neither host DNA degradation nor phage DNA synthesis (DD0) and host DNA degradation with slight DNA synthesis (DS). Upon infection of the non-permissive host with representatives of different complementation groups of mutants either normal lysis occurred or bacterial growth ceased without subsequent lysis. The phenotypic characteristics of the amber mutants were used for partial elucidation of the functions of the affected genes.

Bacteriolysis↗
PubMed1986

Sonographic characterization of carotid plaque: detection of hemorrhage.

By careful evaluation of the sonographic characteristics of carotid plaques, two patterns can be identified: a homogeneous pattern containing uniform echoes corresponding to dense fibrous tissue and a heterogeneous pattern containing mixed echoes and anechoic areas that represent intraplaque hemorrhage pathologically. A prospective study was conducted of 50 patients to determine the accuracy of identifying these different forms of plaque. The patients' carotid arteries were examined by a high-resolution duplex scanner before carotid endarterectomy. The plaques were evaluated carefully by vascular surgeons and pathologists for the presence of intraplaque hemorrhage. In this study, the accuracy of identifying the presence or absence of intraplaque hemorrhage with sonography was 90% (48 of 54); sensitivity, 94% (17 of 18); and specificity, 88% (27 of 31). High-resolution sonography appears to be an accurate means of identifying intraplaque hemorrhage and may ultimately be useful in identifying patients at risk for embolic disease.

Aged↗
PubMed1979

Nonfunctional and functional occlusal contacts: a review of the literature.

A review of the literature on occlusal contacts emphasizes the following points. 1. Contacts in centric occlusion do not correspond to any ideal occlusal diagram. 2. Canine protection and group function appear to correspond to two successive states of the evolving dentition under the effect of abrasion. In most lateral occlusions, two maxillary teeth, of which one is the canine, are involved. 3. During mastication, tooth contacts exist. They occur most often during a sliding movement in which the direction and the origin are variable. This justifies the concept of an occlusal field of mastication. 4. During unilateral mastication, the chewing of the food is performed by working as well as nonworking contact. This imposes the distinction between the chewing and nonchewing sides (functional) and the working and nonworking sides (kinematic). 5. Centric occlusion is the occlusion most often used during mastication. It is also the occlusion for which the masticatory forces are the greatest. 6. The bibliographic data concerning occlusal contracts during swallowing are largely contradictory. It nevertheless seems that the occlusal contacts obey laws nearly the same as those governing the occlusal contact during mastication (sliding on an occlusal field of deglutition, and the importance of centric occlusion).

Deglutition↗
PubMed1976

Wall structure of the Neurospora hyphal apex: immunofluorescent localization of wall surface antigens.

Antisera have been raised in rabbits against three wall fractions from Neurospora crassa. Fractions were separated according to Mahadevan & Tatum (1965), i.e. fraction I, glucan-peptide-galactosamine complex; fraction III, laminarin-like glucan; and fraction IV, chitin. Distinct patterns of immunofluorescent staining were obtained using an indirect staining method. Hyphae stained with antiserum to fraction I showed maximum fluorescence in the apical and/or subapical regions: in both cases, fluorescence showed a sharp decrease with distance behing the subapical region. Hyphae stained with antiserum to fraction III showed faintly fluorescent tips with fluorescence increasing with distance from the tip. Hyphae stained with antiserum to fraction IV showed faint fluorescence, equivalent to levels of autofluorescence, except at the sites of hyphal fractures. Antisera were also raised against whole walls from 24 and 120 h cultures. Hyphae stained with antisera against whole walls which had previously been absorbed to remove antibodies to fractions I, III, and IV showed preferential staining of apices. The uncharacterized tip antigen(s) thus revealed was also demonstrated on immunodiffusion plates. This pattern of immunofluorescence was compared to the fluorescence of apices after staining with an optical brightener. Enzymic dissection procedures did not generally give reliable results with apices from 24 h cultures. Untreated apices appeared amorphous, while a drastic chemical treatment revealed randomly oriented microfibrils which were shown to be alpha-chitin. The apical hyphal walls were significantly thinner than those from more mature hyphal regions.

Antigens, Fungal↗
PubMed1976

Acremonium falciforme as a cause of mycetoma in California.

Three cases of mycetoma were studied in the San Francisco Bay area of northern California during the period from 1960 to 1973. In each case the causal agent was identified on the basis of the histological structure of the granules and by isolation of the etiological agent in pure culture. The fungus in all cases was found to be Acremonium falciforme. This is the first report of A. falciforme occurring as a disease agent in the United States.

Adult↗