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Biomedical subjects

K Porter

Publications and source records attributed to K Porter.

At least 55 records · Page 3Linked to original sources
PubMed1992

An analysis of conditions presenting to a dental hospital emergency clinic.

A retrospective analysis of 1,000 consecutive patients was undertaken to determine the frequency and types of common dental problems presenting to the Emergency and Oral Medicine Clinic at Bristol Dental Hospital. The results show that most attenders presented with problems readily manageable by dental practitioners, but providers of emergency dental services should be aware that rare, but serious, conditions can occur. Information presented in this paper should be incorporated into the design of undergraduate curricula and emergency dental services.

Dental Service, Hospital↗
PubMed1992

Effect on the canine Eck fistula liver of intraportal TGF-beta alone or with hepatic growth factors.

Transforming growth factor-beta canceled the hepatocyte proliferation caused by transforming growth factor-alpha when the two substances were mixed and administered through a disconnected central portal vein branch after creation of an Eck fistula. In contrast, transforming growth factor-beta had no antidotal action on the stimulatory effects of insulin or full test doses of insulinlike factor-2, hepatocyte growth factor, epidermal growth factor or triiodothymanine. A minor antidotal effect on hepatic stimulatory substance activity could be detected, but only with hepatic stimulatory substance was given in doses smaller than those known to cause maximum stimulatory response. These results suggest a highly specific pharmacological and physiological interaction between transforming growth factor-alpha and transforming growth factor-beta in the modulation of liver growth control.

Animals↗
PubMed1991

Travel, heterosexual intercourse and HIV-1 infection.

One hundred and seventy AIDS cases and 547 HIV-1 antibody positive reports of infection in persons who are presumed to have become infected by sexual intercourse between men and women abroad are reviewed. Eighty three percent of people with AIDS and 99% of HIV-1 infected persons were reported to have been exposed in countries where heterosexual spread of HIV infection is well documented (i.e. WHO patterns II or I/II - see below). African countries were commonly cited. The group that had been exposed heterosexually in pattern II or I/II countries was young, and males slightly outnumbered females. Persons who are presumed to have become infected with HIV-1 through heterosexual contact abroad make up a heterogeneous group of travellers which includes holiday makers, business persons, students, refugees and immigrants. Research is needed to identify travellers whose high risk behaviour makes them vulnerable to HIV-1 infection, and to develop effective health education measures for them.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Screening for candidate hepatic growth factors by selective portal infusion after canine Eck's fistula.

Completely diverting portacaval shunt (Eck's fistula) in dogs causes hepatocyte atrophy, disruption of hepatocyte organelles, fatty infiltration and low-grade hyperplasia. The effect of hepatic growth regulatory substances on these changes was assessed by constantly infusing test substances for four postoperative days after Eck's fistula into the detached left protal vein above the shunt. The directly infused left lobes were compared histopathologically with the untreated right lobes. In what has been called an hepatotrophic effect, stimulatory substances prevented the atrophy and increased hepatocyte mitoses. Of the hormones tested, only insulin was strongly hepatotrophic; T3 had a minor effect, and glucagon, prolactin, angiotensin II, vasopressin, norepinephrine and estradiol were inert. Insulin-like growth factor, hepatic stimulatory substance, transforming growth factor-alpha and hepatocyte growth factor (also known as hematopoietin A) were powerfully hepatotrophic, but epidermal growth factor had a barely discernible effect. Transforming growth factor-beta was inhibitory, but tamoxifen, interleukin-1 and interleukin-2 had no effect. The hepatotrophic action of insulin was not altered when the insulin infusate was mixed with transforming growth factor-beta or tamoxifen. These experiments show the importance of in vivo in addition to in vitro testing of putative growth control factors. They illustrate how Eck's fistula model can be used to screen for such substances and possibly to help delineate their mechanisms of action.

Animals↗
PubMed1991

Injuries to dental patients and visitors.

Reports were studied of all incidents of injury and accidents involving outpatients or visitors to Bristol Dental Hospital between 1980 and 1988 inclusive. Seventy-two incidents were reported, two-thirds of which occurred during or just after dental treatment, and usually involved oral soft tissues or teeth. Few accidents that occurred at this time could be attributed to faulty equipment. One-third of accidents occurred outside the treatment area, the resultant injuries were usually minor, although one injury was considered serious enough to warrant legal action to be taken against the Health Authority. Hence, it is important that the provisions of the Health and Safety at Work etc. Act (1974) are implemented in all parts of a dental practice to avoid injury to patients.

Accidents↗
PubMed1991

Synthesis and biological activity of 5-amino- and 5-hydroxyquinolones, and the overwhelming influence of the remote N1-substituent in determining the structure-activity relationship.

A series of 5-amino- and 5-hydroxyquinolone antibacterials substituted at C7 with a select group of common piperazinyl and 3-aminopyrrolidinyl side chains was prepared. These 5-substituted derivatives were compared to the analogous 5-hydrogen compounds for antiinfective activity by using DNA gyrase inhibition, minimum inhibitory concentrations against a variety of bacteria, and in vivo efficacy in the mouse infection model. The influence on the structure-activity relationships of varied substituents at C8 (H, F, Cl) and N1 (ethyl, cyclopropyl, difluorophenyl) was also studied. The results showed that several of the structure-activity conclusions regarding side-chain bulk at C7, the effect of halogen at C8, and the effect of the C5-amino group were greatly influenced by the choice of the N1-substituent. Several outstanding broad spectrum quinolones were identified in this work. In particular, the spectrum and potency of the 7-piperazinyl quinolones could be greatly enhanced by the judicious choice of C5-, C8-, and N1-substituents.

Alkylation↗
PubMed1990

Occupational injuries to dental personnel.

Occupational injuries to dental hospital personnel over 9 years (1980-1988 inclusive) were studied. Some 300 accidents were reported. Over one-half were sharps injuries. Over one-quarter were falls or collisions. Eye injuries accounted for some 10 per cent of incidents, burns and scalds the remainder. Serious complications were rare, but many of the injuries could have been avoided.

Accidents, Occupational↗
PubMed1989

Mood profiles of Masters track and field athletes.

In several studies attributing positive health benefits to running, the benefits include reduced depression, fatigue, anger, and increased vigor. Until now, little research has focused on Masters track and field athletes. The present study reports on 587 men and women Masters who participated in a mailed survey measuring mood states using the Profile of Mood States. In comparison to other groups of athletes, these Masters tend to be less depressed, less angry, and less fatigued. Attribution to lifestyle and maturity with their sport is discussed.

Adult↗
PubMed1988

Primary health care through a community based smoking-cessation program.

The International Conference on Primary Health Care, meeting in Alma-Ata, in the Soviet Union, September 12, 1978, expressed the need for urgent action by all governments, all health and development workers and the world community, to protect and promote the health of all people of the world. The world was caught by the phrase which emerged from this conference, "Health For All by the Year 2000" and many have examined the articles of the Alma-Ata declaration and tried to implement them in their corner of the world. This paper describes a community-based smoking-cessation program which was implemented in the province of Nova Scotia, Canada, during the years 1980-1984. Primary to this project was the belief that people have the right and the duty to participate individually and collectively in planning and implementing their health care. This paper describes one community's effort in putting this belief into practice.

Community Participation↗
PubMed1988

Routine surveillance data on AIDS and HIV infections in the UK: a description of the data available and their use for short-term planning.

In the UK surveillance of AIDS and HIV infection is based on routine reporting systems. Whilst attempts are made to ensure that AIDS data are as complete as possible, numbers of reports fluctuate from month to month for reasons which are described. In 1986 there was an increase in death certificates naming AIDS as a cause of death in patients who were not identifiable in the surveillance data. More active surveillance is now undertaken in order to minimize this and other possible discrepancies. It is probable that most cases of AIDS are reported and therefore these data can be used to describe trends in the epidemic by 'risk group'. Laboratory reports of HIV antibody-positive tests could give an earlier indication of trends because of the long incubation period of AIDS. But these laboratory data are difficult to interpret because they represent an incomplete and biased sample of all positive persons. AIDS cases are still being reported at a rate which is increasing approximately exponentially. Short-term predictions are presented showing a growth in the epidemic which is consistent with previously published predictions. Most cases are in the homosexual risk group. New asymptomatic homosexual patients with HIV antibody are still being identified. The epidemic of AIDS in haemophilia patients should be of finite size although new cases of AIDS are likely to continue to be diagnosed for several years. AIDS due to blood transfusion given in the UK before donor screening appears to be a much smaller epidemic. The epidemic in drug abusers is increasing. Heterosexually acquired AIDS and HIV infections are being reported in small but increasing numbers.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The pathology of posttransplant lymphoproliferative disorders occurring in the setting of cyclosporine A-prednisone immunosuppression.

Posttransplant lymphoproliferative disorders (PTLDs) were diagnosed in 43 patients from the Pittsburgh-Denver series between June 1980 and March 1987. This constitutes a detection rate of 1.7%. Major categories of clinical presentation included a mononucleosislike syndrome, gastrointestinal/abdominal disease, and solid organ disease. The median time of onset in patients initially immunosuppressed with cyclosporine-A (CsA)-containing regimens was 4.4 months after transplant, regardless of tumor clonality. A strong association of PTLD with Epstein-Barr virus (EBV) was observed. A histologic spectrum of lesions from polymorphic to monomorphic was observed. Whereas polymorphic lesions could be either clonal or nonclonal, monomorphic lesions appeared to be clonal in composition. The presence of large atypical cells (atypical immunoblasts) or necrosis did not appreciably worsen the prognosis. Twelve patients had clonal, 13 had nonclonal, and five had both clonal and nonclonal tumors. Clonality was indeterminate in 13 cases. Most patients were treated with a regimen based on reduced immunosuppression and supportive surgery. Almost all nonclonal and about half of the clonal lesions respond to this conservative therapy, indicating that it is an appropriate first line of treatment. This behavior suggests that a spectrum of lesions ranging from infectious mononucleosis to malignant lymphoma constitutes the entity known as PTLD. Some monoclonal tumors can undergo regression, however, apparently in response to host immune control mechanisms. Because of its short latency and strong association with EBV, PTLD is an important model for the study of virus-associated tumor progression in humans.

Adolescent↗
PubMed1987

Prospective study of clinical, laboratory, and ancillary staff with accidental exposures to blood or body fluids from patients infected with HIV.

In a prospective study of 150 health care workers in the United Kingdom who had been accidentally exposed to the human immunodeficiency virus no evidence of transmission was found. Larger studies in the United States and anecdotal accounts in publications from other countries confirm that the risk of occupational infection is very low. Health care workers must adopt safe procedures at all times, however, to avoid exposure to infection.

Accidents, Occupational↗