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Biomedical subjects

K Adams

Publications and source records attributed to K Adams.

At least 73 records · Page 4Linked to original sources
PubMed1990

Crossing state lines of chronic mental illness.

A federal law passed in 1986 required states to develop service plans incorporating each state's own definition of chronic mental illness. This study considered whether the state definitions can be used to identify comparable populations of chronic mentally ill patients and to obtain a meaningful national estimate of the number of such patients. The study applied definitions of chronic mental illness used in ten states to a representative sample of patients receiving public mental health services in West Philadelphia over a two-year period. The prevalence estimates of patients defined as chronically mentally ill ranged from 38 percent using the Hawaii definition to 72 percent using the Ohio definition. The National Institute of Mental Health definition, used as a reference point, produced a prevalence estimate of 55 percent. The authors conclude that the considerable variance among the states in prevalence estimates renders the sum of state counts of chronic mentally ill patients of limited use.

Adult↗
PubMed1989

The effects of 1,6-dinitropyrene on spindle morphology in transformed human cells.

The effects of 1,6-dinitropyrene (1,6-DNP) on the fidelity of cell division were studied in the transformed human fibroblast cell line MRC5VA. Over a dose range of 0.1-10 micrograms/ml of 1.6-DNP, we observed significant increases in the levels of abnormal division stages, associated with damage to the spindle apparatus of the cell. Qualitative changes in spindle morphology and a quantitative decrease in pole-to-pole spindle length were also observed with increasing doses of 1.6-DNP. Such changes in the size and morphology of the spindle corresponded with an accumulation of cells blocked at metaphase. The presence of catalase did not modify the response, suggesting that the effects on the spindle apparatus and cell division were not caused by the generation of radicals but by the direct action of 1.6-DNP.

Catalase↗
PubMed1989

Comparative evaluation of cefazolin and clindamycin in the treatment of experimental Staphylococcus aureus osteomyelitis in rabbits.

A rabbit model for Staphylococcus aureus osteomyelitis was used to compare treatment with clindamycin and cefazolin. Cefazolin (5 mg/kg), cefazolin (15 mg/kg), and clindamycin (70 mg/kg) were injected subcutaneously every 6 h for 28 days. After treatment, S. aureus was found in bone cultures from 22 of 23 control rabbits, 12 of 22 rabbits treated with cefazolin (5 mg/kg), 12 of 23 rabbits treated with cefazolin (15 mg/kg), and 2 of 20 rabbits treated with clindamycin. Drug concentrations in serum, uninfected bone, and infected bone were measured 30 min after cefazolin or clindamycin was injected into a group of rabbits which had been infected for 3 to 4 weeks. Clindamycin gave the highest concentration in infected and uninfected bone. The results of the study showed that clindamycin was superior to cefazolin in the eradication of S. aureus from infected bone in an experimental model.

Animals↗
PubMed1989

Comparative evaluation of daptomycin (LY146032) and vancomycin in the treatment of experimental methicillin-resistant Staphylococcus aureus osteomyelitis in rabbits.

A rabbit model for methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis was used to compare treatment with daptomycin, a new peptolide, and vancomycin. Daptomycin (4 mg/kg) and vancomycin (40 mg/kg) were injected subcutaneously every 12 and 6 h, respectively. After treatment, MRSA was found in bone cultures from 18 of 18 control rabbits, 10 of 17 animals treated with daptomycin, and 11 of 18 animals treated with vancomycin. Drug concentrations were measured in serum, uninfected bone, and infected bone 1 h after daptomycin or vancomycin was injected in a group of rabbits that had been infected for 3 to 4 weeks. Vancomycin was present at the highest concentrations in infected and uninfected bone. The results of this study suggest that daptomycin was similar to vancomycin in the eradication of MRSA from infected bone in an experimental model of osteomyelitis.

Animals↗
PubMed1989

The many benefits of assessment/care management.

These data provide a preliminary sense of demand for services among older people. They were collected in somewhat limited geographic areas by sponsors who are known in the community. Therefore, responses may reflect perceptions of specific sponsors, the degree to which services are available in various communities, and the level of familiarity with services. However, the data give a strong indication that long-term care services are viewed as complementary, and respondents understand the need for multiple services in assisting older people. The groups or factors were remarkably similar across the six sites, as were the rankings of services according to the percentage of people who rated each one or two on a five-point scale of importance. However, there was a great deal of variation in the percentage of respondents rating the services one or two by site. These results suggest that interest in services as packages is very consistent but that the degree of interest in services may vary from one market to another. Again, this may be the result of perceptions of the sponsor, the degree of availability of services in different markets or idiosyncrasies of different populations. Services are what will allow older people to remain in their homes and to maintain a maximum degree of independence. Whether people opt for a retirement community setting for the camaraderie, security and convenience it offers, or to remain in the broader community, coordination and integration are clearly necessary to appropriate, efficient and effective use and delivery of services. It is becoming clear that older people recognize this fact and will increasingly seek integrated service packages.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Gastric carcinogenesis: a model for the identification of risk factors.

In a series of extensive studies on gastric carcinogenesis, we have used Sprague-Dawley rats to examine the morphologic, histochemical, and biochemical effects of risk and protective factors on N-methyl-N'-nitro-N-nitroso guanidine (MNNG)-induced tumors in an attempt to link early observations with the end-point lesion, gastric cancer. We have observed that the putative risk factors sodium chloride (NaCl); a mixture of bile acids; aspirin; alcohol; and nitrite enhance MNNG-induced neoplasia of the gastric mucosa. On the other hand butylated hydroxyanisol (BHA), Se and difluromethylornithine (DFMO) were protective and inhibited the induction of gastric mucosal neoplasia. In most cases, early changes detected by a number of criteria correlated with the end-point, gastric neoplasia. This model appears to be useful in screening and evaluating chemicals for risk for or protection against gastric cancer.

Animals↗
PubMed1986

Temporal interactions in the Lewis lung tumour between cytotoxic drugs and acute or fractionated radiotherapy.

The suggestion was examined, that acute irradiation might be combined with some cytotoxic drugs to produce a supra-additive antitumour effect by timing the second treatment to coincide with the period of repopulation by tumour cells that survived the first treatment. The possible interaction of fractionated irradiation with drugs was also studied. Lewis lung tumours were treated in vivo with acute radiation (20 Gy) and 1-(2-chloroethyl)-3-(4-methyl cyclohexyl)-1-nitrosourea (MeCCNU, 10 mg X kg-1), cyclophosphamide (CY, 120 mg X kg-1) or cis-dichlorodiammine platinum (cis-Pt, 10 mg X kg-1) with time intervals ranging from simultaneous to 9 days in either sequence. Tumour response was measured by regrowth delay and combination responses were evaluated relative to calculated "additivity envelopes". With CY and cis-Pt, tumour volume response was approximately additive, whether the drugs were administered simultaneously, or up to 7 days before or after radiation. However, with simultaneous administration, MeCCNU and radiation were supra-additive in terms of volume response, although only additive using a clonogenic cell survival assay. A transplantation experiment suggested that the supra-additive volume response may be due to retarded growth rate in regrowing tumours. In the fractionation studies, drugs were given either at the beginning or at the end of a regime of 5 daily 6 Gy doses. With CY and MeCCNU the drugs were more effective when given with the first radiation dose, but with cis-Pt either regime was equally effective. There was no evidence that repopulation could be exploited to improve therapeutic effect with any of the combination treatments used in this study.

Animals↗
PubMed1986

Emergence of nitrosourea resistant sublines of Lewis lung tumour following MeCCNU treatment in vivo.

Several different drug retreatment protocols were employed to examine the emergence of resistance to MeCCNU in Lewis lung tumours. Previous studies suggested that although the majority of cells in untreated Lewis lung tumours were sensitive to MeCCNU, there was a very small proportion of resistant cells (approximately 0.001%) that limited "tumour cure' with that drug. If such cells were inherently drug resistant then it should be possible to derive highly resistant tumours by repeated drug treatment. In the first experiment tumours were treated with a single high dose of MeCCNU (35 or 40 mgkg-1) and on regrowth, transplanted into fresh mice and tested for drug sensitivity. Using both excision cell survival and growth delay endpoints, only approximately 25% of tumours were significantly resistant to the test dose, suggesting that many tumours resist the effects of the drug for reasons other than the presence of inherently drug resistant cells. One of the tumours (R4), that regrew after the initial treatment and appeared to be resistant to the test treatment, was retreated with a further 30 mgkg-1 MeCCNU and became more resistant. This line, designated R4/1, was cross-resistant to the other nitrosoureas, BCNU and CCNU, but not to cyclophosphamide, melphalan, cis-platinum or ionising radiation. The effect of treatment dose on the kinetics of MeCCNU resistance development was also studied in a retreatment regimen where the tumours were allowed to regrow and then transplanted into fresh hosts for the next treatment. Resistance developed more quickly at an intermediate dose of 15 mgkg-1 than at 7.5 mgkg-1 where the selective pressure was lower, or at 30 mgkg-1 where there was probably extinction of partially resistant cells. Resistance to MeCCNU developed even more quickly when tumours were retreated several times in the same host, although in a similar experiment with cyclophosphamide no resistance occurred.

Animals↗
PubMed1986

Gray-scale (B-mode) sonography of the maxillary sinus.

Gray-scale sonographic examination of the maxillary sinuses of five normal volunteers and 12 patients with maxillary sinus disease was performed and correlated with other radiologic imaging modalities, clinical follow-up, and, in two cases, surgical findings. B-mode scanning is a rapid, potentially useful, nonionizing diagnostic modality for determining whether the maxillary sinuses contain fluid or are normally aerated. Sonography may also demonstrate mucosal thickening, focal soft tissue masses, and complex collections.

Adolescent↗
PubMed1985

Positive treadmill stress tests post myocardial infarction in patients with single-vessel coronary disease.

To investigate the possibility that patients with single-vessel coronary artery disease (CAD) and recent myocardial infarction (MI) can have ST segment depression on post infarction treadmill testing due to ischemia, we studied 16 such patients who underwent cardiac catheterization and exercise testing after MI. Of the 11 patients with ST segment depression on treadmill testing, 10 failed to increase their ejection fraction and nine had a focal worsening of wall motion during exercise radionuclide ventriculography. Seven of these 11 patients had hypokinesis or normokinesis in the suspected area of infarction. In contrast, four of the five patients without ST segment depression on treadmill stress testing had an increase in ejection fraction with stress which was significantly greater than that seen in patients with ST depression (7.2% vs 0%, p less than 0.05). Short-term follow-up (1.1 years) revealed continued post infarction angina in 10 of the 11 patients with positive treadmill stress tests. Four of these patients underwent either percutaneous transluminal angioplasty or surgery. We conclude that positive post infarction treadmill tests due to exercise-induced ischemia may occur in patients with single-vessel CAD and may be associated with continued angina that requires surgical intervention.

Adult↗
PubMed1985

Beta-blocker therapy after myocardial infarction: secondary prevention in all patients?

The ability of beta-adrenergic blocking drugs to prevent death in patients after myocardial infarction has been demonstrated by several large trials. However, the need to treat patients at low risk has been challenged. Retrospective analysis of the data from one of these studies plus results from many additional studies have shown that electrical, mechanical and ischemic complications after myocardial infarction imply a high risk of subsequent death or recurrent infarction. On the other hand, absence of complications with a negative exercise tolerance test, good exercise tolerance, absence of arrhythmias and normal increase of ejection fraction with exercise documents a very low risk. These considerations lead to the following practical implications: The physician should watch for any evidence of left ventricular dysfunction or arrhythmia. Any such complication justifies treatment or more intensive study. Patients without complications can be further characterized with exercise testing, exercise radionuclide blood pool ventriculography, and Holter monitoring. If these tests expose risk indicators, treatment or more study should again be recommended. Because the beta-blockers are probably life-saving in a considerable portion of the patients with moderate and high risk, the decision to treat or not to treat should be made with due, affirmative consideration. In those patients with a carefully documented uncomplicated course and who have a normal exercise test and appropriate increase in ventricular ejection fraction with stress, beta-blockade is probably of no benefit. Under these conditions, a physician and patient might logically decide not to use the drug.

Adrenergic beta-Antagonists↗
PubMed1985

Immediate causes of death in acquired immunodeficiency syndrome.

We evaluated the immediate causes of death in 54 adults who underwent an autopsy and were diagnosed as having died of the acquired immunodeficiency syndrome between April 1980 and October 1983. The study group included 25 Haitians, 19 homosexual men, five intravenous drug abusers, two hemophiliacs (type A), and three with no known risk. Fourteen died of central nervous system diseases: 11 of Toxoplasma encephalitis, one of progressive multifocal leukoencephalopathy, one of viral encephalitis, and one of intracerebral hemorrhage. Thirty died of respiratory failure; 16 of Pneumocystis carinii pneumonia, ten of cytomegalovirus pneumonia, one of multiple infections, one of interstitial pneumonia, and two of bacterial pneumonia. Two died of overwhelming generalized infections: one of Mycobacterium avium-intracellulare and one of listeriosis. Six died of disseminated Kaposi's sarcoma, while the remaining two persons died of Toxoplasma myocarditis (one) and one of shock resulting from a percutaneous liver biopsy, respectively. There were differences in the immediate causes of death between Haitians and homosexuals as follows: 63% of homosexual men died of either P carinii pneumonia or Kaposi's sarcoma vs 20% of Haitians. In contrast, 72% of Haitians died of other opportunistic infections as compared with 21% of homosexuals. There has not been an increase in the proportion of cases diagnosed premortem since 1982 and overall, only 32 (58%) were diagnosed premortem; the rest were diagnosed only at autopsy. This study provided evidence that 42% died of currently untreatable diseases.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Resistance to the mitotic inhibitor NY 3170 in Chinese hamster ovary cells.

Mutant CHO cells have been isolated which are resistant to NY 3170, a member of the metahalone group of antimitotic drugs. One NY 3170 resistant mutant is hypersensitive to the microtubule-stabilising drug, taxol, but there is not a reciprocal relationship between levels of resistance to these drugs in CHO cells, since it was found that sixteen other mutants isolated on the basis of taxol resistance had wild type levels of NY 3170 resistance. Our NY 3170 resistant mutants are cross-resistant to vincristine and other mutants, selected on the basis of vincristine resistance, are cross-resistant to NY 3170.

Animals↗
PubMed1984

Identification of a subpopulation of MeCCNU resistant cells in previously untreated Lewis lung tumours.

A variety of experimental endpoints including excision cell survival, lung colony curability, tumour regrowth delay and i.m. tumour curability following MeCCNU alone and combined with gamma-radiation, were used to define the MeCCNU cell survival curve down to "tumour cure" level in previously untreated i.m. Lewis lung tumours. The survival curve was found to be biphasic, the tumour cells being markedly resistant to MeCCNU at high doses of the drug. Below 10 mg kg-1 the survival curve was exponential through the origin with a D10 of approximately 2 mg kg-1, while above 15 mg kg-1 the D10 was approximately 25 mg kg-1. From linear extrapolation of the terminal part of the cell survival curve to zero drug dose, it appeared that about 1 in 10(5) (or 0.001%) of tumour cells were resistant to MeCCNU.

Animals↗
PubMed1983

Computed tomographic demonstration of hemobilia.

A patient with hemobilia presumably due to a small hemangioma in the liver is presented. The condition was diagnosed by computed tomography (CT) done immediately following hepatic arteriography and confirmed by hem-positive duodenal aspirates on two occasions.

Aged↗