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Biomedical subjects

J Russo

Publications and source records attributed to J Russo.

At least 235 records · Page 13Linked to original sources

Inferoseptal myocardial infarction: another cause of precordial ST-segment depression in transmural inferior wall myocardial infarction?

Electrocardiographic ST-segment depression in the anterior precordial leads is a frequent observation during the initial hospital phase of acute transmural inferior myocardial infarction (MI), but is of uncertain significance. No available clinical studies have examined the prevalence of inferoseptal necrosis complicating inferior MI. Therefore, the clinical course, electrocardiographic features, radionuclide angiograms and cardiac enzyme changes in 57 patients with transmural inferior MI who did not have prior anterior or concomitant "true posterior" MI, associated anterior or posterolateral asynergy by radionuclide ventriculography, or left or right bundle branch block were reviewed retrospectively. Patients were categorized according to the presence (group A) or absence (group B) of precordial ST-segment depression and according to the presence (group I) or absence (group II) of radionuclide septal wall motion abnormalities. There were no significant differences in global left ventricular ejection fraction (group A, 49 +/- 8, group B, 52 +/- 41; group I, 51 +/- 7, group II, 51 +/- 6), right ventricular ejection fraction (group A, 45 +/- 9, group B, 42 +/- 7; group I, 43 +/- 8, group II, 41 +/- 8), or clinical outcome in the hospital. However, chi-square analysis revealed a significant (p less than 0.05) association between the presence or absence of septal asynergy and the presence or absence of precordial ST depression. In addition, average peak creatine kinase elevation (group I, 761 +/- 164 IU; group II, 698 +/- 178 IU) attained marginal significance by paired t test (p = 0.06). Precordial ST-segment depression during transmural inferior MI is frequently associated with septal asynergy by gated radionuclide angiography (15 of 26 patients, 58%).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Enzyme Tests↗

Relationship of natural killer cytotoxicity to clinical and biochemical parameters of primary human breast cancer.

We have determined the natural killer (NK) activity of peripheral blood lymphocytes obtained from 121 women undergoing surgery for primary breast cancer. NK activity was measured using 51Cr-labeled K562 target cells and effector: target ratios of 100:1, 50:1 and 10:1. The patients' lymphocytes gave a wide range of values with a mean (+/- S.E.) cytotoxicity of 22.6% +/- 1.3, and a median of 20.9% at the 50:1 effector:target ratio. These results did not differ significantly from the mean and median NK levels obtained with the peripheral blood lymphocytes of normal blood donors (mean = 23.1% +/- 1.9, median = 18.8%). Mean NK activity determined at the first postsurgical examination (less than or equal to 6 months postoperative) was significantly lower than the mean NK activity at surgery. The most significant decreases were seen in patients undergoing chemotherapy prior to the first follow-up examination. Subsequent tests (greater than 6 mo, less than or equal to 12 mo) show a recovery of NK activity to preoperative levels. A negative correlation was seen between NK level and maximum tumor diameter. NK levels also varied with tumor histiotype. No association was seen between NK levels and either the number of involved lymph nodes, pathologic tumor grade, the presence of estrogen or progesterone receptor, or the age, menopausal status or smoking history of the patients. A positive correlation was seen, however, between NK levels and number of pregnancies and live births.

Adult↗

The clinical utility of the dementia rating scale for assessing Alzheimer patients.

Community residing patients with mild (n = 18) or moderately severe (n = 16) Alzheimer's disease and controls (n = 23) were given Mattis' Dementia Rating Scale (DRS) and a brief measure of confrontation naming selected from the Boston Naming Test (BNT). The DRS was shown to be a reliable and clinically useful measure of mental status in patients with Alzheimer's disease. The DRS subscales and the BNT had excellent internal consistency reliabilities and the total DRS score (TDRS) was shown to be generally unrelated to gender and education. Among the dementia patients, performance on the TDRS was significantly associated with functional competence. The two dementia samples had similar profiles on the DRS and BNT, with the mild subjects performing significantly better than the moderately severe subjects on each measure. Extending the range of DRS subscales would improve this measure's utility as an evaluation instrument.

Activities of Daily Living↗

Rebound following hemodialysis of cimetidine and its metabolites.

The effect of hemodialysis on the pharmacokinetics of cimetidine and its metabolites was studied after the intravenous administration of a 300-mg dose of cimetidine. Serum concentrations were monitored before, during, and after hemodialysis. Cimetidine pharmacokinetics were similar to those in patients with end-stage renal failure, with a total body clearance of 3.3 +/- 1.0 mL/min/kg and a half-life of 4.1 hours. Dialysis caused an initial decrease in serum concentrations for cimetidine, hydroxymethyl cimetidine, and cimetidine sulfoxide, followed by a rebound in serum concentrations immediately after treatment. Dialysis clearances, as calculated from extraction ratios, were 83 +/- 15, 90 +/- 16, 93 +/- 24, and 126 +/- 23 mL/min for cimetidine, hydroxymethyl, sulfoxide, and creatinine, respectively. After four hours of dialysis, 10% +/- 3.2% of the cimetidine dose was recovered in the dialysate. The sulfoxide and hydroxymethyl metabolites demonstrated relatively constant serum concentrations for up to 24 hours postdosing, and therefore, estimates of their terminal half-lives were not possible. In one patient, accumulation of both metabolites occurred during multiple dosing. Hemodialysis is an ineffective means of decreasing the total body load of cimetidine and its metabolites. Presumably, sequestration of the drug in body tissues decreases the amount of drug present in the blood available for dialysis removal, with rebound occurring due to postdialysis re-equilibriation between blood and extravascular fluids.

Adult↗

Cimetidine kinetics during resuscitation from burn shock.

Severely burned patients suffer from rapidly changing metabolic and hemodynamic abnormalities that could alter drug kinetics. The kinetics of cimetidine, commonly used in the prophylaxis of acute stress erosions, were studied during fluid resuscitation of 11 patients with mean burn sizes of 45% total body surface area. Six patients were studied after the completion of fluid resuscitation. Total clearance, steady-state volume of distribution, and cimetidine t1/2 did not change between the early period after burn and after fluid resuscitation, but before the completion of fluid resuscitation patients had lower renal and greater nonrenal cimetidine clearance than after resuscitation. The increase in nonrenal cimetidine clearance resulted in decreased urinary recovery of unchanged drug, 50.7 +/- 14% during fluid resuscitation and 81.0% +/- 6% after resuscitation.

Adult↗

Memory, attention, and functional status in community-residing Alzheimer type dementia patients and optimally healthy aged individuals.

This paper reports the results of two studies. Investigation I examined patterns of cognitive performance in healthy controls and mildly-to-moderately impaired patients with senile dementia of the Alzheimer type (SDAT). Investigation II focused on the degree to which cognitive test scores could predict functional competence in SDAT patients. The samples included 23 controls, 18 mildly impaired SDAT, and 16 moderately impaired SDAT patients. Cognitive measures included tests of attention, calculation, recognition memory, recall, and orientation. The functional competence measures included maintenance, communication, and recreational abilities. Investigation I found that the patterns of attention and memory that distinguish control from mildly impaired SDAT patients differ from those that distinguish mildly from moderately impaired SDAT patients. Investigation II found that it is possible to predict behavioral competence in individuals with dementia from a knowledge of their attentional and memory deficits.

Activities of Daily Living↗

Medical school pressures and their relationship to anxiety.

This study examined the relative importance of medical school pressures according to their relationship with symptoms of anxiety, as evaluated by a standardized/normative measure of anxiety. As many as 206 (34 per cent) of the total sample (N = 605) of students reported symptoms of anxiety above the median of a normative population of psychiatric outpatients. Using multiple regression, six medical school experiences significantly accounted for 36 per cent of the variance in anxiety scores. These included: perceived threat, mastering knowledge, anonymity, little time for personal activities, peer competition, and long hours. These results are important for two reasons. Contrary to the traditional belief that stressful experiences are necessary for future medical practice, research suggests that stress and anxiety are major causes of cognitive dysfunction. The identification of those experiences that are most anxiety provoking should help therapists and educators to develop intervention strategies in order to reduce anxiety and increase the quality of medical education.

Adult↗

An evaluation of naloxone as a gastric cytoprotective agent during hemorrhagic shock.

Administration of naloxone, an opiate antagonist, is known to improve survival from hemorrhagic shock and to reverse the effects of septicemia on gastric mucosal O2 tension and potential difference (PD). We tested these potentially cytoprotective actions in the ex-vivo canine gastric chamber model with acid, bile, and hemorrhagic hypotension. Naloxone (2 mg/kg IV bolus, then 2 mg/kg/hr IV) was given before or during shock. Naloxone did not affect oxygen consumption, the bile-induced drop in PD, or the transmucosal oxygen consumption, the bile-induced drop in PD, or the transmucosal movements of H+, Na+, K+, and fluid. The reduction in average mucosal lesion formation with naloxone pretreatment (5.4 +/- 1.2 vs. 2.8 +/- 0.5%) was not statistically significant (p = 0.07). Similarly, administration of naloxone after the onset of shock also failed to protect the mucosa from stress ulceration. We conclude: 1) naloxone does not inhibit the effects of topical bile on the gastric mucosal barrier; 2) naloxone has no apparent effect on local gastric vascular resistance during hemorrhagic shock; and 3) the therapeutic potential of naloxone as an anti-ulcer drug is questionable. 24GM 23095

Acute Disease↗

Clinical evaluation of a small-volume infusion system in surgical intensive care patients.

This study evaluated flow-rate accuracy, safety, and dependability of an infusion system manufactured by the 3M Company. The Small Volume Infusion (SVI) system is portable and consists of a mechanically powered infuser, calibrated flow-regulating set, and syringe. Intravenous fluids and drugs were administered to six surgical intensive care patients. Forty-one trials were carried out at infusion rates of 1, 10, or 30 ml/h. Flow rate varied less than or equal to 10 percent from the intended infusion rate in the majority of trials. One patient experienced pain at the injection site and one malfunction occurred. The SVI system is a safe, dependable alternative method for the administration of intravenous fluids and drugs. The device may prove to be particularly useful for the administration of drugs not requiring changes in flow rate during infusion or in situations where fluid restriction is desirable.

Critical Care↗

Transaminase elevations in patients receiving bovine or porcine heparin.

Eighty-six patients who required heparin therapy were randomly assigned to receive bovine or porcine heparin. Abnormal concentrations of alanine transaminase and aspartate transaminase developed during treatment in 59.3% and 26.7% of patients, respectively. Patient characteristics that significantly influenced the development of abnormal alanine transaminase concentrations were male sex and higher baseline enzyme values. Transaminase concentrations returned to normal in 80% of patients after heparin therapy was discontinued and in 20% during therapy. Analysis of transaminase concentrations in all 86 patients showed that 95% had some increase in enzymes during treatment. Mean maximal increase over baseline for all patients was 3.6 for alanine transaminase and 3.1 for aspartate transaminase (range, 1.0 to 15). Lactate dehydrogenase concentrations became abnormal in 35.7% of patients. Lactate dehydrogenase isoenzyme determinations in 6 patients showed elevated hepatic fractions. No clinical symptoms of hepatic dysfunction were seen.

Adolescent↗

Interrupted pregnancy as an indicator of poor prognosis in T1, 2, N0, M0 primary breast cancer.

We examined the records of women with primary breast cancer for a history of pregnancy and live births. The patients were all histopathologic T1, 2, N0, M0 white females, untreated post modified radical mastectomy. Patients with a history of interrupted pregnancies have a significantly shorter time to recurrence than those with normal pregnancy history. A trend toward a lower incidence of highly differentiated histological pattern is also observed in cancers from these patients.

Abortion, Spontaneous↗

In vitro metabolism of 7,12-dimethylbenz[a]anthracene in mammary epithelial cells from rats with different susceptibilities to carcinogenesis.

These in vitro metabolism studies of 7,12-dimethylbenz[a]anthracene (DMBA) by rat mammary epithelial cells were initiated to determine whether differences in the incidence of DMBA-induced mammary carcinomas observed between young virgin, old virgin and parous Sprague-Dawley rats can be explained through variations in their ability to metabolize DMBA. The results show that: (a) qualitatively, the metabolic profiles produced by epithelial cells from the 3 groups of rats were similar; (b) the level of metabolism with cells from young virgin and parous rats was similar but was 1.5-2.0 times higher than that obtained with cells from old virgin rats; c) the major ethyl acetate-soluble metabolite detected by h.p.l.c. from cells of old virgin and parous rats was the trans-8,9-dihydrodiol (50-65% of total metabolites), whereas the majority of the radioactivity following incubation with cells from young virgin rats co-eluted with very polar metabolites (65% of total metabolites); and (d) the amount of phenolic metabolites produced by young virgin rat cells was higher than in old virgin or parous rat cells. The data suggest that the susceptibility of young virgin rat mammary cells to DMBA may be due in part to the conversion of a greater percentage of DMBA to phenolic compounds and to water- and ethyl acetate-soluble polar metabolites, and event known to influence the susceptibility of cultured cells to the cytotoxic effects of DMBA.

9,10-Dimethyl-1,2-benzanthracene↗

Enamel demineralization by mouthrinses containing different concentrations of sucrose.

Intra-oral enamel demineralization tests, involving rinsing with sucrose solutions (5, 1, 0.5, or 0.3%) at varying frequencies during a 1.5-hour period, showed that demineralization was a function of the total sugar dose (frequency of rinsing times concentration). Two rinses with a 5% solution caused demineralization, nine rinses were needed in the case of a 0.5% solution, and none occurred after nine rinses with a 0.3% solution. Remineralization was also observed and apparently occurred after exhaustion of the sucrose supply.

Adult↗

Enamel demineralization potential of dietary carbohydrates.

Mouthrinses with 5% solutions of different sugars were tested for their demineralizing effect on blocks of bovine enamel covered with a layer of S. mutans cells and carried in a palatal prosthesis. The extent of demineralization, as measured by the permeability of the enamel to iodide, was similar for fructose, glucose, and sucrose, less for maltose and lactose, and least for galactose.

Adult↗

Basis of cellular autonomy in the susceptibility to carcinogenesis.

This paper summarizes our contributions in the basic understanding of the different susceptibility of the mammary gland to carcinogenesis according to age and parity history. Mammary carcinomas induced by the administration of 7,12-dimethylbenz-(DMBA) to young virgin rats arise from undifferentiated terminal ductal structures called terminal end buds (TEBs). TEBs, that normally differentiate into alveolar buds (ABs) and lobules, under the influence of DMBA develop intraductal proliferations which progress to carcinoma. The high susceptibility of the young virgin rat TEBs to neoplastic transformation is due to its large proliferative compartment, with cells cycling every 10 hours, and to a higher 3H-DMBA uptake. Progressive differentiation of TEBs into ABs and lobules or their regression to terminal ducts (TDs) is seen with aging. Complete differentiation of the gland is attained through pregnancy and lactation or through exogenous administration of chorionic gonadotrophin. The greater differentiation of the gland is manifested as permanent structural changes, consisting in the disappearance of TEBs and in a diminution of the number of TDs due to their differentiation into ABs and lobules. This greater differentiation results in a diminished or total refractoriness of the gland to the carcinogen because ABs and lobules have a lower proliferative compartment, and a longer cell cycle than TEBs and TDs. Cells of parous rats have both in vivo and in vitro lower DMBA-DNA binding capacity, lower DNA synthesis and greater ability to repair DMBA-damaged DNA than cells of young virgin rats. The more efficient DNA repair capacity of the parous rat mammary gland is demonstrated by the induction of unscheduled DNA synthesis and a removal of DMBA-DNA adducts.

9,10-Dimethyl-1,2-benzanthracene↗

Molecular and cellular basis of the mammary gland susceptibility to carcinogenesis.

Mammary carcinomas induced by the administration of 7,12-dimethylbenz(a)anthracene (DMBA) to young virgin rats arise from undifferentiated terminal ductal structures called terminal end buds (TEBs). TEBs that normally differentiate into alveolar buds (ABs) and lobules under the influence of DMBA develop intraductal proliferations which progress to carcinoma. The high susceptibility of the young virgin rat TEBs to neoplastic transformation is due to its large proliferative compartment, with cells cycling every 10 hr, and to a higher (3)H-DMBA uptake. Progressive differentiation of TEBs into ABs and lobules or their regression to terminal ducts (TDs) is seen with aging. Complete differentiation of the gland is attained only through pregnancy and lactation. The greater differentiation of the gland is manifested as permanent structural changes, consisting in the disappearance of TEBs and in a diminution of the number of TDs due to their differentiation into ABs and lobules. This greater differentiation results in a diminished or total refractoriness of the gland to the carcinogen because ABs and lobules have a lower proliferative compartment and a longer cell cycle than TEBs and TDs. Cells of parous rats have both in vivo and in vitro a lower DMBA-DNA binding capacity, a lower DNA synthesis and a greater ability to repair DMBA damaged DNA than cells of young virgin rats. The more efficient DNA repair capacity of the parous rat mammary gland is demonstrated by the induction of unscheduled DNA synthesis and a removal of DMBA-DNA adducts.

9,10-Dimethyl-1,2-benzanthracene↗