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Biomedical subjects

S Warren

Publications and source records attributed to S Warren.

At least 91 records · Page 5Linked to original sources

Increasing incidence of adenocarcinoma of the lung.

Review of the histology of 219 lung cancers initially diagnosed at Lutheran General Hospital, Park Ridge, Illinois, in 1963-1967 and 1974-1976, confirms the increasing incidence of adenocarcinoma. This is due to an increase of adenocarcinoma in men. In women, the incidence of adenocarcinoma was higher than squamous carcinoma in the earliest period (44% adeno, 18% squamous). The percentage of women with lung cancer has also significantly increased from 19% to 31%, which increases the overall incidence of adenocarcinoma of the lung. As the number of women with lung carcinoma has increased, there has been no change in the percentage of adenocarcinoma in women.

Adenocarcinoma↗

Multiple sclerosis and associated diseases: a relationship to diabetes mellitus.

One hundred multiple sclerosis (MS) patients and hospital controls were compared for coexisting illnesses, and other illnesses among their family members. The patients and controls were compared for allergy, migraine, and cancer among themselves and for a family history of these illnesses. The findings were negative. However a relationship was found between multiple sclerosis and diabetes mellitus. More MS patients than controls were either diabetic or reported a blood relative with diabetes. MS patients who reported another blood relative with MS were also more likely to report a family history of diabetes mellitus than MS patients who had no other relative with multiple sclerosis.

Adult↗

Comparative effects of aspartate and glutamate during myocardial ischemia.

The effects of amino acids aspartate (Asp) and glutamate (Glu) on recovery of contractile function and preservation of compliance were studied in globally ischemic, isolated, blood-perfused cat hearts. Ischemia-induced declines in contractility and compliance were measured with an intraventricular fluid-filled balloon. Asp and Glu were delivered to isolated hearts in physiological salt solution (PSS) containing 10 mM glucose, just prior to, and intermittently during (every 15 min for 1 min) 1 h of normothermic ischemia. Isolated hearts which received Asp and Glu showed recoveries of left ventricular (LV) developed pressure of 79 +/- 8 and 50 +/- 7% of their preischemic values, respectively, compared to 34 +/- 7% in hearts perfused only with PSS. These alterations of contractile function were paralleled by changes in LV compliance. The addition of amino-oxyacetate, and aminotransferase inhibitor, to Asp- containing PSS markedly attenuated the beneficial effects of this amino acid. The results indicate that certain amino acids can protect the ischemic myocardium, presumably through effects on intermediary metabolism.

Animals↗

Mesothelioma relative to asbestos, radiation, and methylcholanthrene.

The carcinogenicity of chrysotile asbestos fibers (Canadian and Rhodesian) for the mesothelium of pleura and peritoneum of NEDH rats was explored by injection of 2 mg of asbestos fibers suspended in saline intratracheally, intrapleurally, or intraperitoneally, with or without ancillary radiation treatment (1,000 rad to the whole body of parabiont rats or 2,000 rad to the right thorax of single rats), or alternatively, by injection of asbestos plus 1 mg of 3-methylcholanthrene. A highly significant incidence of mesothelioma (3.8%) was noted in 159 rats treated with asbestos alone, as compared with 0.1% in 1,417 control rats. Additional treatment with radiation or 3-methylcholanthrene increased this incidence to 11.8% and 25.5%, respectively, the latter increase alone being significant at the .01 level of probability.

Animals↗

Quantitation of left ventricular wall motion in normal subjects: comparison of various methods.

Computer-assisted analysis of percent change in the square root of area in each of 12 consecutive 30-degree, pie-shaped ventricular segments was obtained in 48 normal subjects who underwent cardiac catheterization and left ventriculography. The information obtained permitted establishment of objective confidence limits for normal left ventricular regional wall motion. As an index of dynamic changes in segmental wall motion, the percent change in the square root of area method compared favorably with existing radius, area, hemichord, and chord methods. It also possessed a variety of theoretical advantages over these techniques: 1) large numbers of points were analyzed, 2) wall motion disorders in all areas except base were evaluated, 3) taking the square root of area's percent change provided both area information with least splay and an average measure of radius.

Adult↗

Some observations on a program attaching public health nurses to family physicians' offices.

This study examined a program attaching public health nurses to specific family physicians practicing in the community. It compared the work of attached and nonattached public health nurses in both the urban and rural sections of a health district in Ontario, Canada. It found that attached nurses receive a greater proportion of their referrals from family physicians, see a greater percentage of elderly patients, and deal with proportionately more psychosocial cases. The study also indicated that the attached public health nurse does not complain of physician misuse of her services and that, once a referral has been made, communication between the physician and public health nurse improves.

Canada↗

A life-cycle conference series; education for general practice.

An all around educational programme for general practice trainees involving a conference and seminar cirriculum was developed, based on a life-cycle concept. In addition to emphasizing the study of usual life stresses and crisee for individuals and families, the programme encouraged the contribution of resource people from many related medical disciplines and also from the non-health sciences. Detailed planning allowed the structuring of the conference over an academic year. Clearly defining the objectives for each meeting led to effective evaluation and enhanced the educational process.

Congresses as Topic↗

Renin requires a structural alteration prior to activation by renal kallikrein.

Renal kallikrein may be the physiologic protease which activates renin. In vitro activation of plasma inactive renin by renal kallikrein, however, requires prior dialysis of plasma to pH 3.3, which is thought to destroy endogenous plasma kallikrein inhibitors. We present evidence that low pH directly alters renin to facilitate its activation by renal kallikrein. Untreated normal plasma was combined with pH 3.3 dialyzed and neutralized plasma and incubated with semipurified human renal kallikrein 2.3 X 10(-2) to 4.6 IU/ml, pH 7.5, 25 degrees C for 1h. All concentrations activated renin in acid-treated plasma; whereas, in untreated plasma 4.6 IU/ml renal kallikrein was ineffective. In combinations of untreated and acid-treated plasma, the percent renin activated by renal kallikrein was equal to the percent acid-dialyzed plasma present. When acid-treated plasma was combined with buffer, activation was complete and quantitatively the same as in the untreated and acid-treated plasma combinations. The data suggest inactive renin itself is altered structurally by pH 3.3; this change in the renin molecule is necessary for kallikrein activation. Renal kallikrein may not be the sole in vivo activator of renin.

Chemical Phenomena↗

Risk of cancer subsequent to low-dose radiation.

Prominent among media items related to the Three Mile Island episode were prophecies of future cancers. The credibility of some of these estimates are discussed. The average person has been exposed by the age of 50 to 2.5 rad (0.025 Gy) from natural background. We define low doses as under 25 rad (0.25 Gy). The most heavily exposed members of the general population during the Three Mile Island event received 83 mrad (0.83 mGy). Those exposed to 2500 mrad (25 mGy) would show no pathologically recognizable effects of radiation though there is evidence that chromosomal damage may occur with doses about 1 rad (0.01 Gy). An official stated among the consequences of the Three Mile Island accident that two additional cancer deaths would result. No epidemiologist could detect such an increase in the population at risk. It has been generally agreed that the linear hypothesis is useful for determining protection standards, not prognosis. Objective criteria for pathologic diagnosis of cause-effect relations are presented.

Humans↗

Structural comparisons of the aggregates of tobacco mosaic virus protein.

The coat protein of tobacco mosaic virus forms numerous aggregates, including the small A-protein, the disk, and two helical forms. The structures of the disk, the helical protein forms, and the virus are compared. Most of the differences are in the conformation of the chain between residues 89 and 113, which lies in the region of protein at the center of the virus, inside the RNA. It is disordered in the disk, but has a fixed conformation in the virus and the protein helices. The differences between the virus and the two helical protein forms are largely in the conformations of arginines and carboxylic acids in this region.

Macromolecular Substances↗

Hormonally induced tumors of the reproductive system of parabiosed male rats.

Parabiosis of intact male rats to castrated males or oophorectomized females for a period of approximately 20 months resulted in three interstitial cell tumors of the testis. When unilateral nephrectomy was added to the parabiotic procedure in ten pairs, eight interstitial cell tumors of the testis and four adenocarcinomas of the prostate occurred in the target male parabionts. These changes were preceded by elevations in luteinizing and follicle-stimulating hormone levels in the serum of the castrates and high levels of testosterone and, to a lesser degree, of androstenedion in the target partners developing the tumors.

Adenocarcinoma↗

Effects of N-dimethyl propranolol (UM-272) on isolated cardiac mitochondria and microsomes.

N-dimethyl propranolol (UM-272) has been shown to protect the heart from injury produced by ischemia. In the present study we examined the effects of UM-272 on the function of isolated rabbit cardiac mitochondria and microsomes. Concentrations of 13 micrometers or below were without effect on these organelles. UM-272 (130 micrometers) significantly decreased respiratory control of mitochondria utilizing glutamate plus malate, or succinate, as substrates. At 1.3 mM, UM-272 increased the initial rate of basal oxygen consumption, and decreased the rate of ADP-stimulated respiration. UM-272 was slightly more potent than d,1-propranolol. At a concentration of 1.3 mM, UM-272 significantly decreased the rate and maximum amount of 45CaCl2 accumulated by microsomes in the presence of ATP and oxalate. Concentrations of drug that suppress cellular metabolism are close to those required to prevent ischemic injury. We suggest that sarcolemmal and intracellular actions of the drug which help to depress oxygen demand and ATP utilization may account for part of the drug's protective effects.

Adenosine Triphosphate↗

Late effects of successive massive doses of radiation on parabiont rat pairs.

Parabiosis of rats permits one partner to survive 1000 R X-radiation if the other is shielded. This dose to the previously shielded partner after intervals of 5, 10 or 30 days tests the ability of the first irradiated partner to recover and, in turn, support the second. The effectiveness of this can be measured by the late effects induced in the pair. Lifespan was shortened by 100--150 days following a 5-day interval, by 30 days following a 10-day interval and not shortened following a 30-day interval. The incidence of leukaemia was about 6 per cent in each group, close to that in control pairs. Shortening the interval between the irradiations decreased the average age of death from leukaemia. No solid lymphoid tumours were induced in the doubly irradiated pairs. The incidence of osteogenic sarcoma was 1.6 per cent in controls and 12.9 per cent in the pairs with both partners irradiated.

Animals↗

Tissue enzyme changes in parabiotic rats with subcutaneous lymphoma or fibrosarcoma.

A solid lymphoma implanted into normal inbred Kx rats and one partner of parabiotic pairs caused appreciable decreases in hepatic ornithine aminotransferase and arginase about a week earlier (4-6 days after implantation) in single hosts than in parabiotic hosts. By 18-21 days significant decreases in both enzymes were apparent in the host partner also. The hepatic thymidine kinase showed a fivefold elevation in single hosts 4 days after implantation; by 14 days in its levels were about 200 times above normal and had also risen in the parabiotic hosts (20-fold) and host partners (fourfold). Implantation of fibrosarcoma caused qualititatively similar but generally less pronounced changes in these three enzymes in livers of single hosts, parabiotic hosts, and host partners. The splenic thymidine kinase 14 days after implantation was increased from control levels of about 3 U/g to 50.6, 44.8, and 13.5 U/g in single hosts, parabiotic hosts, and host partners, respectively. At later stages, 17-20 days after implantation of the lymphoma, appreciable amounts of thymidine kinase appeared in the plasma: The units of activity per milliliter were 6.2 in single hosts, 0.79 in parabiotic hosts, and 0.55 in host partners (control less than 0.05). Our observations on the changes in hepatic and splenic enzymes in parabiotic rats suggest that effects of neoplasms on distant host tissues are mediated by humoral factors. The less pronounced responses in parabiotic than in single hosts indicate that the tumor-free partner affords some "protection" against these systemic effects.

Animals↗

Mammary and other tumors as a response to radiation and multiple stresses.

Parabiosis of paired NEDH rats and subsequent irradiation of one produced multiple stresses, particularly altered hormonal milieu. Benign mammary tumors developed in 8.6% of the control pairs, 12.7% of the shielded partners, and 19.7% of the irradiated rats. Mammary cancers developed in 5% of control pairs, 14.2% of the shielded partners, and 11.9% of the irradiated rats. With increased amounts of prolactin, the rate was 50% in shielded partner, 10% in the irradiated rats. Mesenchymal sarcoma develop at the anastomosis in parabiont rats. Their incidence rate in single controls is 3.1%, in parabiont control pairs 12.5%, in pairs with one partner irradiated 16.6%, and with both irradiated 23.1%. The incidence rate in other parts was increased threefold over controls in the irradiated partners. Radiation appears to be the dominant factor in both mammary and anastomotic tumors.

Adenofibroma↗