Receptivity of African-American men to prostate cancer screening

OBJECTIVE

The lifetime risk of prostate cancer among African-American men is two times higher than that of white men. Mortality from the disease is almost three times greater in African-Americans than in whites. This study assesses the receptivity of older (fifty to seventy-four years of age) African-American men (n = 86) in Chicago to periodic (annual and semiannual) prostate cancer screening.

METHODS

A telephone survey conducted in January and February 1993, was used to collect data on subject sociodemographic background and medical history and to gather information on knowledge, attitudes, and beliefs about prostate cancer and screening. Univariate and multivariate analyses were carried out to identify factors associated with subject receptivity to annual and semiannual screening.

RESULTS

Logistic regression analyses revealed that receptivity to annual and semiannual (every six months) examination is strongly associated with the degree to which screening is perceived as a salient and coherent (i.e., important, effective, and convenient) preventive health behavior. An additional factor independently associated with willingness to go through semiannual screening was subjects' awareness that African-American men are at increased risk for prostate cancer compared to white men.

CONCLUSIONS

Findings from this study suggest that African-American men are willing to undergo prostate screening and are more receptive to annual than semiannual screening. Participation in screening may be facilitated by the provision of health education messages that emphasize the salience and coherence of early detection and elevated population risk.

Normoglycemia (not hypoglycemia) optimizes outcome from middle cerebral artery occlusion

We examined the effects of serum glucose concentration during middle cerebral artery (MCA) occlusion in the cat on death rates in animals that died from hemispheric edema and on infarct size in animals that survived. We occluded that MCA permanently in some groups and released the clip after 8 h in others. By injecting or infusing glucose solutions, saline, or insulin, we maintained six animal groups steadily either hyper-, normo-, or slightly hypoglycemic before and for 6 or 8 h after permanent or 8-h temporary MCA occlusion. Studies with these groups revealed a distinct optimal outcome with normoglycemic animals. In three additional groups, we altered the glycemia after permanent occlusion from hyper- to normo- or hypoglycemia and from normo- to hyperglycemia. Two of the three hypoglycemic groups (8-h reversible and permanent hyper- to hypoglycemic occlusions) yielded the worst outcomes in this study, with > 10x larger median infarcts than the best outcome group (normoglycemic permanent occlusion). Hyperglycemia also was detrimental and increased infarct size and mortality after permanent occlusion. Restoring the cerebral blood flow after 8 h of occlusion increased the death rate from hemispheric edema compared with a maintained occlusion. Following permanent MCA occlusion, converting from normo- to hyperglycemia or vice versa yielded outcomes intermediate between a sustained normo- or hyperglycemia. A regression analysis of the normo- and hyperglycemic groups and the two groups with glycemia altered after permanent occlusion showed a significant linear correlation between glycemia level at and 1 h after MCA occlusion and median infarct size.

Modeling adherence to colorectal cancer screening

BACKGROUND

An explanatory framework referred to as the Preventive Health Model was used to identify factors associated with prospective adherence to colorectal cancer screening.

METHODS

Data on sociodemographic, psychosocial, social influence, and program factors were collected via telephone survey for 501 older adult members of an independent practice association-type health maintenance organization. Subjects were later mailed fecal occult blood tests for completion and return. Adherence was defined as the return of the tests within 90 days.

RESULTS

Structural analysis shows that for men (N = 145), perceived self-efficacy (OR = 1.4), salience and coherence of testing (OR = 2.3 for a 5-point increment on a 30-point scale), and exposure to health education interventions (OR = 6.8) were significant independent predictors of intention to adhere and of adherence. Among women (N = 185), predictors were age (OR = 1.8) and salience and coherence of testing (OR = 1.8 for a 5-point increment on a 30-point scale).

CONCLUSIONS

These findings indicate that for both men and women, adherence is influenced strongly by the extent to which the behavior is judged to make sense in everyday life. It also appears that additional education and encouragement may persuade men and younger women to participate in screening.

Efficacious experimental stroke treatment with high-dose methylprednisolone

BACKGROUND AND PURPOSE

Recent studies reveal success in treating spinal cord trauma with early, high-dose methylprednisolone. As in spinal cord research, failure to find therapeutic effects with steroids in studies of acute stroke treatment may reflect institution of treatment too late and at too low dosage. We presently test the efficacy of stroke treatment with methylprednisolone administered early and at high doses using a cat temporary middle cerebral artery occlusion model.

METHODS

We occluded the middle cerebral artery for 4 hours in 24 pentobarbital-anesthetized cats. To enhance the probability of brain injury, we maintained the cats' serum glucose concentrations at high levels both during occlusion and for 6 hours afterward. Using a blinded, randomized study design, we treated 12 cats with methylprednisolone (30 mg/kg IV infused over 15 minutes starting 30 minutes after occlusion followed by 5.4 mg.kg-1.h-1 IV for the next 23 hours) and 12 control cats with vehicle. During and for 8 hours after occlusion, we monitored cerebral blood flow, brain and rectal temperatures, and multiple cardiovascular and blood compositional parameters. We assessed brain pathological outcome after animal survival for 4 days or after acute death from hemispheric edema.

RESULTS

Experimental and control animals showed similar early mortality rates (treated, 3/12; controls, 4/12). However, surviving methylprednisolone-treated cats (n = 9) showed a mean infarct size more than six times smaller than in the control animals (n = 8) (mean +/- SEM, 2.4 +/- 0.7% versus 15.6 +/- 6.2% of the ischemic territory, respectively; P < .05). The methylprednisolone-treated animals also showed less marked reduction in cerebral blood flow during ischemia than did the controls (mean +/- SEM, 58 +/- 5% versus 74 +/- 4%; P < .005).

CONCLUSIONS

Administering methylprednisolone at high doses early after onset of ischemia significantly reduces tissue injury in cats that survive 4 days of temporary middle cerebral artery occlusion. This improvement in outcome occurs in the setting of significant increases in ischemic cerebral blood flow. However, methylprednisolone treatment did not reduce hemispheric edema in animals that died early after temporary middle cerebral artery occlusion.

Screening for colorectal neoplasia: physicians' adherence to complete diagnostic evaluation

This prospective study was done in a health maintenance organization colorectal cancer screening program to determine whether 166 persons found to have abnormal fecal occult blood test results typically underwent complete diagnostic evaluation (i.e., either colonoscopy or barium enema x-ray plus flexible sigmoidoscopy). Chart audit data show that 137 (82%) subjects contacted a physician to discuss follow-up. A complete diagnostic evaluation was recommended to only 52 (38%) patients who talked with a physician. Forty-two (81%) patients who were advised to get a complete diagnostic evaluation actually complied. Significant differences in clinical findings were observed for patients who did and did not have a complete diagnostic evaluation.

Adherence to continuous screening for colorectal neoplasia

Continuous screening is defined as the periodic provision of an opportunity for diagnostic testing to a population of individuals who are asymptomatic and at increased risk for disease. If screening is offered periodically irrespective of response to an earlier screening invitation, this situation may be referred to as serial screening. When continuous screening is made available only to individuals who had tested previously, population member response is referred to as repeat screening. This study assessed adherence to serial- and repeat-colorectal cancer screening among older adult members of an independent practice association-type health maintenance organization (HMO) in two consecutive rounds of screening. In the first screening round, fecal occult blood tests (FOBTs) were sent to 1,565 subjects who were randomly assigned to receive usual care or behavioral interventions intended to encourage testing. Overall, 647 (41%) subjects completed and returned their tests. In the second screening round, FOBTs were mailed again to all subjects; however, the interventions were discontinued. Logistic regression analysis results shows that first-round testing was a significant independent predictor of serial adherence for subjects older than 65 years of age (odds ratio[OR] = 10.8) and those younger than 65 years of age (OR = 10.9); and a significant negative association between exposure to first-round intervention and serial adherence (OR = 0.5) was found among younger subjects. Among first-round adherers, age was significantly and positively related to repeat adherence (OR = 1.6). However, exposure to first-round intervention and having an abnormal FOBT result were significantly and negatively associated with repeat adherence (OR = 0.5 and OR = 0.4, respectively). The results of this study reported here indicate that previous screening is a strong predictor of serial adherence, and special efforts may be required to achieve high levels of serial and repeat adherence among younger adults. Additional research is needed to understand why persons with abnormal screening test results are unlikely to engage in repeat screening.

Reasons for non-entry in randomized clinical trials for breast cancer: a single institutional study

Reasons for patient non-entry in randomized clinical trials (RCTs) assessing oncologic treatment modalities are not well documented in the literature. We have prospectively recorded reasons for RCT non-entry in breast cancer patients at St. Michael's Hospital, Toronto. From September 1984 to November 1989, 592 consecutive patients were evaluated through the clinical trials office. One hundred six out of the 592 patients were placed into a RCT (17.9%). Protocol ineligibilities accounted for 273 non-entries (46.1%) and protocol eligible but not entered patients accounted for 213 (36.0%) non-entries. The most common reason for protocol ineligibility was advanced age (94 patients). The most common reason for protocol eligible but not entered patients was patient refusal (148 patients). A total of 272 patients in both non-entered groups were identified as having reasons for non-entry that were potentially correctable. In summary, protocol ineligibilities account for the majority of non-entered patients, but patient refusal accounted for the single largest group of potentially correctable non-entries. More dissemination about the merit of RCTs in the lay press and amongst primary care physicians must take place if we are to expediently and efficiently answer important oncologic questions.

Hyperglycemic versus normoglycemic stroke: topography of brain metabolites, intracellular pH, and infarct size

Hyperglycemia aggravates brain pathologic outcome following middle cerebral artery (MCA) occlusion in cats. We presently determined if hyperglycemia during occlusion leads to high lactic acid accumulations in the ischemic MCA territory. We measured brain metabolite concentrations in 14 MCA territory sites at 0.5 and 4 h following occlusion in hyper- (20 mM) and normoglycemic (5 mM) cats and correlated these results with previous brain pathologic findings. Hyper- versus normoglycemia during MCA occlusion resulted in significantly higher lactate concentrations in the ischemic territory and more numerous loci with lactates greater than 17 mumol/g. At 0.5 h of occlusion, ATP levels were lower in normoglycemic cats, while at 4 h, ATP was similarly reduced (40%) in both glycemia groups. At 4 h, PCr was more reduced in hyperglycemics secondary to a greater brain tissue acidosis. Carbohydrate substrates at 0.5 h were more markedly depleted in normoglycemics, likely limiting lactate accumulation (34.3% versus only 5.0% of sites in hyperglycemics with glucose less than 0.5 mumol/g). Although lactate was markedly elevated at both 0.5 and 4 h in hyperglycemic ischemic territories, clip release at 4 versus 0.5 h yields a significantly poorer brain pathologic outcome. Correspondingly, intracellular pH, calculated from the creatine kinase equilibrium, was more markedly depressed at 4 than at 0.5 h of occlusion, demonstrating a time-dependent dissociation between tissue lactate and hydrogen ion accumulations. The present findings show that following MCA occlusion (a) hyperglycemia increases the magnitude and topographic extent of marked tissue lactic acidosis, (b) infarct size following 0.5 h of clip release correlates more closely with tissue acidosis than with lactate concentrations, (c) ischemic tissue ATP concentrations correlate poorly with infarct size, (d) normoglycemia limits lactate accumulation during focal ischemia because tissue glucose is depleted, and (e) early during ischemia, tissue buffering or antiport mechanisms may prevent marked increases in intracellular hydrogen ion activity.

Hemorrhagic infarct conversion in experimental stroke

STUDY OBJECTIVE

This study investigated the relations between hemorrhagic infarction and occlusion, release, levels of glycemia, brain energy state, and lactate content after cerebrovascular occlusion.

DESIGN

Prospective, controlled laboratory investigation.

TYPE OF PARTICIPANTS

One hundred six pentobarbital-anesthetized cats.

INTERVENTIONS

The middle cerebral artery was occluded with a Yasargil clip transorbitally either temporarily (0.5, four, and eight hours) or permanently. Normoglycemic and hyperglycemic animals were closely monitored for eight hours. Brain pathology was assessed after two weeks' survival or at the time of spontaneous animal death. Topographic brain metabolite studies were carried out after four hours of middle cerebral artery occlusion.

MEASUREMENTS AND MAIN RESULTS

Morphometric quantitation of cerebral hemorrhage and infarction and fluorometric determinations of blood and brain tissue, glucose, glycogen, lactate, adenosine triphosphate, and phosphocreatine from 16 topographic brain sites were carried out. Twenty-one of 82 (25.6%) animals evaluated neuropathologically showed hemorrhagic infarcts. Occluding the artery in hyperglycemic animals caused fivefold more frequent and 25-fold more extensive hemorrhage into infarcts than in normoglycemic animals. Temporary occlusion with clip release after four hours in hyperglycemic animals caused the most extensive hemorrhage into infarcts. Most hemorrhages into infarcts (81%) took place in animals that died within a few hours after they experienced ischemia and that showed infarction and marked edema of the entire middle cerebral artery territory. Linear regression analyses demonstrated a close relation between hemorrhage into infarcts and near-total energy depletion (adenosine triphosphate, less than 0.3 microM/g; phosphocreatine, less than 0.5 microM/g) in brain sites that showed extremely high tissue lactate concentrations (more than 30 microM/g). The biochemical changes that correlated with hemorrhage into infarcts were more marked than those with infarcts without hemorrhage.

CONCLUSION

Hyperglycemia and restoration of blood flow to ischemic territories were strong risk factors for hemorrhagic infarct conversion. Concomitant tissue metabolic changes suggest that marked tissue energy depletion accompanied by acidosis damages brain vessels and renders them penetrable for edema fluid and, ultimately, red blood cell extravasation.

Behavioral interventions to increase adherence in colorectal cancer screening

This investigation was a randomized controlled trial to determine the impact of health education interventions on the return of mailed fecal occult blood (FOB) tests (FOBT adherence) in a colorectal cancer screening program. The study sample included 2,201 men and women aged 50 to 74 years who were members of an Independent Practice Association (IPA)-type health maintenance organization (HMO). Subjects were randomly assigned to a "usual care" Control Group (advance letter, screening kit, reminder letter), and Treatment Groups 1 (usual care + reminder call), 2 (usual care + self-held screening booklet + reminder call), or 3 (usual care + self-held screening booklet + instruction call + reminder call). Bivariate analysis revealed significant differences in adherence (P less than .001) across study groups: Control Group (27%), Group 1 (37%), Group 2 (37%), Group 3 (48%). In addition, a significant positive association between age and adherence (P less than .001) was found. Logistic regression analysis revealed an interaction between sex and treatment. Adherence among men in all treatment groups increased significantly (P less than .0001) in relation to Control Group males. Men in Group 3 also were more likely to adhere than those in Group 2 (P less than .01) or Group 1 (P less than .01). Among women, adherence was significantly higher in Group 3 than in Group 2 (P less than .03), Group 1 (P less than .025), or the Control Group (P = .0008). The primary reason cited for nonadherence was perceived inconvenience of the FOB testing procedure.

Educating allied health professionals to provide care for cancer patients and their families

From 1985 to 1988, a state-wide program of cancer education was offered to community-based allied health professionals (AHPs) at five different program sites in Pennsylvania. During this three-year period, 512 social workers, clergy, dieticians, physical therapists and others received training to increase their knowledge about cancer and counseling, improve their supportive attitude regarding cancer patients and families, and decrease stress related to their work with this population. Overall, the Program was successful in reaching AHPs working with cancer clients who had little formal training in the cancer field. At the beginning of training, it was observed that AHPs with initially higher levels of education and more years of work experience with cancer patients had higher levels of counseling knowledge. Those who were women, worked in hospitals, or had worked with cancer patients longer exhibited higher levels of cancer knowledge. Participants who were women and who had more education had reported lower levels of job stress. Among those AHPs who completed the training courses, cancer knowledge increased by 14 percent. In addition, knowledge related to counseling cancer patients and their families improved by 11 percentage points. Perceived job stress among the AHPs also declined by 10 percent. Finally, participant supportive attitude concerning cancer clients improved.

Delayed decreases in specific brain mitochondrial electron transfer complex activities and cytochrome concentrations following anoxia/ischemia

Hyperglycemic, but not normoglycemic cats exposed to anoxia develop neurologic signs following reoxygenation including fasciculations, focal and tonic-clonic seizures and coma after a symptom-free period. These symptomatic hyperglycemic cats may develop brain edema and will show diffuse neuronal injury or brain infarction depending on length of survival. Brain mitochondria isolated from symptomatic but not asymptomatic cats have decreased ADP- and uncoupler-stimulated oxygen consumption rates. Since impaired respiration could result from altered electron transport chain function, we measured cytochrome c, b, and aa3 concentrations and the activities of the five electron transfer complexes in isolated brain mitochondria. In symptomatic cats marked alterations were present in particular in complex IV, cytochrome oxidase, with a 57% reduction in activity and a 45% reduction in prosthetic group (cytochrome aa3) concentrations. Less marked reductions in other segments of the chain included 27% and 41% decreases, respectively, in cytochrome c concentrations and in electron transfer complex II, succinate:ubiquinone oxidoreductase activity. Cytochrome b concentrations and complex I, II and V activities were unchanged. Small but significant decreases in cytochrome aa3 concentrations (18%) and cytochrome oxidase activity (20%) were also present in mitochondria from postanoxic hyperglycemic cats prior to appearance of neurologic signs. These results indicate that delayed decreases in the activities of specific electron transfer complexes are correlated with impaired mitochondrial respiration and neurologic deterioration in postanoxic hyperglycemic cats. However, it is presently unclear if these postanoxic brain mitochondrial alterations are primary or secondary events in the development of brain injury.

Adherence to colorectal cancer screening in an HMO population

This study aimed to determine factors that influence fecal occult blood test performance in colorectal cancer screening. A random sample was selected of men and women ages 50 to 74 years of age who had been mailed a fecal occult blood testing kit in a screening program in fall 1986. One year after initial test mailing, sample group members (n = 504) were surveyed by telephone. Four months later, the survey sample received a second fecal occult blood test mailing. Multivariable analysis for subjects with validated past fecal occult blood test status (n = 322) revealed the past testing was positively associated with physician encouragement of screening, age, the belief that cancer is curable, perceived test efficacy, and strong intention to do testing. It also was discovered that persons who felt that they had little control over their health were more likely to have done past testing. Preliminary analysis of prospective adherence showed that the strongest statistically significant independent predictor was past test performance. Prospective adherence among past nontesters (n = 121) was associated with expressed commitment to do fecal occult blood testing and reported presence of colorectal cancer risk factors. Analysis of adherence among past testers (n = 201) revealed that belief in colorectal cancer curability and age were significant predictors. The findings reported here indicate that factors influencing adherence among past nontesters differ from those for past testers. Overall, these results suggest that to increase participation in colorectal cancer screening, physicians and other health professionals should (a) deliver educational messages that increase awareness of risk factors for colorectal cancer and curability of the disease, and (b) elicit from potential screenees a commitment to engage in recommended preventive behaviors. It may also be well to consider "tailoring" messages for past nontesters and past testers, respectively, by emphasizing colorectal cancer risk factors and highlighting curability.

Delayed onset of neurologic deterioration following anoxia/ischemia coincides with appearance of impaired brain mitochondrial respiration and decreased cytochrome oxidase activity

We previously demonstrated markedly inhibited brain mitochondrial respiration only in cats that (a) were hyperglycemic at anoxia and (b) had neurologic signs, i.e., fasciculations in tongue or facial muscles or focal seizures following reoxygenation. However, since the relationship between time of onset of mitochondrial dysfunction and neurologic signs was unclear, in the present study we killed postanoxic cats immediately when signs first appeared. Cerebrocortical homogenates and isolated brain mitochondria only from symptomatic cats showed markedly inhibited substrate-, ADP-, and uncoupler-stimulated respiration rates. Cytochrome oxidase activity and cytochrome aa3 concentrations were also markedly reduced in these mitochondria. Since brain mitochondrial function was impaired when neurologic signs first appeared, mitochondrial alterations are an important early organellar change correlated with development of neurologic deterioration following anoxia.

Determiners of fatal reperfusion brain oedema

Brain oedema is an important aspect of infarction from cerebrovascular occlusion. In a cat stroke model where the middle cerebral artery (MCA) was reversibly or permanently occluded, we analyzed the incidence of fatal hemispheral oedema in 35 normo- (6 mM) and 35 hyperglycaemic (20 mM for 6 hours) animals, with (N = 45) and without (N = 25) restoration of blood flow with clip release at 4 and 8 hrs of occlusion. Fatal hemispheral oedema occurred in 23% of cats (16/70) while hyperglycaemia, for one, and restoration of blood flow, for another, each quadrupled its occurrence. Further, evidence of remote oedema in the form of posterior cingulate cortical pressure atrophy from transtentorial herniation was found in animals that were allowed to survive for 2 weeks and that exhibited infarcts that affected 12 to 95% of the MCA territory. Thus, hemispheral oedema in association with MCA occlusion developed sufficiently markedly as to cause transtentorial herniation in 47% of all cats (33/70). We carried out biochemical analyses in 14 hyper- and 10 normoglycaemic cats after 4 hrs of MCA occlusion for ATP, phosphocreatine (PCr), lactate, glucose and glycogen. The biochemical findings then were correlated with the occurrence of reperfusion oedema following clip release after 4 hrs of occlusion point-by-point in the brains. Linear regression analyses of the brain metabolic and pathologic data revealed highly significant (p less than 0.001) correlations of acute oedema with brain tissue ATP and PCr reductions less than 1.5 microM/g, with lactic acid accumulation greater than 20 microM/g and with the extents of reduction in brain tissue glucose concentrations in the ischaemic territories.(ABSTRACT TRUNCATED AT 250 WORDS)

Fatal strokes in hyperglycemic cats

Hyperglycemia is associated with three- to fourfold larger infarcts than normoglycemia following permanent middle cerebral artery occlusion in cats. We investigated the effects of glycemia on brain outcome when middle cerebral artery blood flow was restored (clip release) after 4 hours of occlusion. Seven of 13 hyperglycemic (22 mM) and one of 12 normoglycemic (6 mM) anesthetized cats developed total middle cerebral artery territory infarcts and hemispheric edema and died of brainstem compression. The remaining six and 11 cats recovered fully and later showed no or only small infarcts. Compared with permanent occlusion, restoration of blood flow after 4 hours reduced infarct volume in all normoglycemic and hyperglycemic cats that survived, but caused a much higher proportion (54% vs. 17%) of hyperglycemic and, for the first time, one normoglycemic cat, to die of infarct extension, hemorrhagic infarct conversion, and total territory edema. Thus, clip release after 4 hours caused some cats to show reduced and others to show augmented tissue damage. Rendering cats hyperglycemic substantially worsened their outcome after reperfusion by increasing their death rate from total territory edema sevenfold. Our results demonstrate that risk/benefit analyses for recanalization efforts in humans should take serum glucose concentrations into account.

Effects of mentoring on job satisfaction, leadership behaviors, and job retention of new graduate nurses

Findings from a study on the effects of using mentors to help new graduate nurses adjust to professional nursing revealed improved job satisfaction and increased leadership behaviors. The use of mentors over longer periods to help new nurses make the transition from school to nursing practice is a successful orientation strategy receiving increased attention by nursing staff educators.

A photoelastic study of stress induced by framework design in a maxillary resection

Support of a framework and obturator in a patient with an acquired maxillary defect is diminished by the removal of a portion of the palate and alveolar bone. The intent of this study was to investigate, by three-dimensional photoelastic analysis, the stress transmission that occurs with four commonly used retentive systems. The individual designs were facial cast circumferential retention with palatal plating, swing-lock design with palatal plating, facial cast circumferential retention and palatal cast circumferential clasp reciprocation, and facial cast circumferential reciprocation with palatal I-bar retention. Stresses were observed and compared on the palate and around the teeth of the four models.

Delayed neurologic deterioration following anoxia: brain mitochondrial and metabolic correlates

Hyper- but not normoglycemic cats exposed to 8 min of anoxia show neurologic signs (fasciculations, myoclonic jerks, seizures) that develop after a symptom-free period. We examined brain mitochondrial function and metabolite concentrations at 0, 1, 3, and 5 h following exposure to anoxia, to correlate biochemical findings with the presence ("symptomatic") or absence ("presymptomatic") of neurologic signs. Brain mitochondria isolated postexposure only from symptomatic cats showed markedly decreased (-50%), state 3 (ADP-stimulated), and uncoupler-stimulated respiration rates with NAD- and FAD-linked substrates. Respiratory control and ADP/oxygen (ADP/O) ratios remained unchanged, indicating, respectively, that coupling and efficiency of ATP synthesis were preserved. Thus, inhibition of electron transport chain function, not phosphorylative activity, may be rate limiting for respiration. During anoxia, hyperglycemic cats showed higher brain lactate levels (26 versus 20 mumol/g), but similar ATP and phosphocreatine concentrations, compared with normoglycemic cats. After exposure, in all animals lactate and phosphocreatine were restored to control levels, whereas ATP remained at 85%. Cats that became symptomatic demonstrated four- to sixfold increases in lactate and 50% reductions in phosphocreatine. At 3 and 5 h postexposure, symptomatic animals showed significant reductions in ATP concentrations. We conclude that although initially asymptomatic, hyperglycemic cats exposed to anoxia undergo a neurologic deterioration over several hours following reoxygenation that is correlated with inhibition of mitochondrial respiration, increases in tissue lactate, and decreases in energy state.

Some reasons for compliance and noncompliance in a health maintenance organization breast cancer screening program

Impressive reductions in breast cancer mortality have been demonstrated through regular screening programs using mammograms and clinical breast examinations. Nevertheless, only a small proportion of American women obtain annual mammograms. The US HEALTHCHECK breast cancer screening program offered free breast cancer screening to age-eligible members of a Health Maintenance Organization. Subscribers were mailed packets of materials and asked to return a Breast Risk Assessment Form to determine their eligibility to receive a free mammogram. This study was conducted to assess why women did or did not return a Breast Risk Assessment Form. Brief telephone interviews were conducted with a random sample of compliers and noncompliers (n = 502). Women who complied by returning the Risk Assessment Form said more frequently that they were unlikely to get breast cancer, were older, and more likely to have read the materials and to have rated them positively than women who did not return the Risk Assessment Form.

Hyperglycemia enlarges infarct size in cerebrovascular occlusion in cats

We investigated the influence of serum glucose concentration on infarct size following middle cerebral artery occlusion in cats. These animals were deprived of food for 48 hours and infused with 1) saline for 1 hour before and 8 hours after occlusion (n = 8), 2) 10% glucose solution for 1 hour before and 6 hours after occlusion and saline for 2 additional hours (n = 8), or 3) 10% glucose for 1 hour before and saline for 8 hours after occlusion (n = 5). Nineteen cats killed after 2 weeks' survival were subjected to morphometric infarct size determinations. Eight normoglycemic and 11 hyperglycemic cats exhibited infarcts affecting 10.2 +/- 3.4% and 29.5 +/- 6.5% (mean +/- SEM) of their middle cerebral artery territories, respectively (p less than 0.02). Cats of the two hyperglycemic groups showed similarly sized infarcts. However, two of eight (25%) of cats with preocclusion and postocclusion hyperglycemia died 8 and 24 hours after occlusion with infarction of the entire middle cerebral artery territory, marked hemispheral edema, and brainstem compression. Our results demonstrate that serum glucose concentration at the time of large cerebral vessel occlusion influences stroke outcome.

Cerebral hemiatrophy--correlation of human with animal experimental data

We report the neuropathologic findings in a 63-year-old white male with a history of birth asphyxia, cerebral palsy, seizures and mild mental retardation in conjunction with similar brain pathologic findings in animal models of perinatal asphyxia. The human case showed a left cerebral hemispheric hemiatrophy associated with an extensive ulegyria involving all cerebral lobes on that side and a single microscopic focus of cortical atrophy in the right hemisphere. Among a large number of experimental perinatal asphyctic exposures only an occasional animal, like the human case described, showed unilateral hemispheric injury with softening and necrosis if examined early and ulegyria with hemispheric hemiatrophy if examined late. The present paper suggests that perinatal asphyxia under specific pathophysiologic conditions may cause unilateral brain injury. Our experimental studies suggest the specific condition of perinatal asphyxia potentially causing unilateral or asymmetrical brain damage is marked hypoxemia combined with substantial reductions in blood pressure but without circulatory collapse. Given these conditions, the asymmetry of the brain damage likely reflects fetal head position within the gravitational field relative to the heart. With disturbed cerebral blood flow autoregulation from asphyxia, the gravitational field likely accentuates the ischemia of those brain areas most elevated above the level of the heart. Thus, we postulate head position may play a pivotal role in defining brain regions that are damaged in hypotensive perinatal asphyxia. This interpretation may affect the intensive care of hypoxemic, hypotensive newborns aimed at minimizing the risk of brain damage.

A photoelastic study of rests on solitary abutments for distal-extension removable partial dentures

With a distal-extension removable partial denture, maximum use of existing oral structures can aid in the total support of the prosthesis and reduce the force on the solitary abutment. Four rests with relieved and unrelieved guide plates were evaluated for optimum stress distribution around the root of a solitary premolar abutment. These rests were the mesial, the distal, the mesial and distal, and the continuous rest. The findings demonstrated that The continuous rest had the most favorable stress concentration. All other rest designs demonstrated more lateral stress than the continuous rest. Relieved guide plates demonstrated 58% less maximum shear stress in the apical portion than unrelieved guide plates.

Hyperglycemia preserves brain mitochondrial respiration during anoxia

We examined brain mitochondrial function in normo- (5 mM) and hyperglycemic (50 mM) cats after 8 min of anoxia. In anoxic normoglycemic cats, mitochondrial state 3 respiration with NAD-linked substrates glutamate or pyruvate (both plus malate) was inhibited 30-50%. The uncoupler carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP) maximally stimulated respiration, indicating that inhibition of phosphorylation, not impairment of electron transport, substrate transport, or oxidation was present. State 3 respiration with succinate (plus rotenone) was unaffected. Mitochondrial respiratory control ratios trended toward reductions whereas ADP/O ratios remained unchanged. In contrast, brain mitochondria from anoxic hyperglycemic cats showed no such inhibition of state 3 respiration and no differences in function from normo- and hyperglycemic control animals except for trends toward loose coupling. Significantly higher brain tissue glucose concentrations were present in hyperglycemic controls as the only metabolite difference compared to normoglycemic controls. At the end of anoxia, hyperglycemic cats exhibited significantly higher cortical lactate and glucose levels but similarly reduced high-energy phosphate concentrations compared to normoglycemic cats. These results demonstrate that increased availability of glucose to gray matter as a consequence of hyperglycemia maintains normal mitochondrial state 3 respiration during exposure to anoxia. Previous survival studies have shown that lower serum glucose concentrations during anoxia are relatively brain protective. This result indicates that the presently described alterations in mitochondrial respiration must be fully reversible.

Brain metabolic correlates of hypoxic-ischemic cerebral necrosis in mid-gestational sheep fetuses: significance of hypotension

Mid-gestational sheep fetuses exposed to marked hypoxia for 2 h remain brain intact if MABP is maintained above 30 mm Hg. On the other hand, similarly hypoxic fetuses, if they experience reductions in MABP below 30 mm Hg, develop foci of necrosis that predominantly affect hemispheric white matter and neostriatum. Cortex damage is more restricted and is usually associated with more massive underlying white matter damage. The present study examines the brain metabolic basis for the important role of hypotension in brain injury development in marked hypoxia. Sheep fetuses rendered hypoxic by respiring their ewes with 11% oxygen (fetal PaO2 = 8-12 mm Hg) in which MABP was maintained above 30 mm Hg showed increases in brain lactic acid concentrations to 7-13 mumol/g but unaltered energy charge. In contrast, fetuses that sustained MABP reductions below 30 mm Hg showed increases in lactic acid concentrations in vulnerable structures to 16-24 mumol/g accompanied by marked decreases in energy charge. The vulnerable structures also showed reductions in fructose concentrations but a variable behavior of other brain metabolites including phosphocreatine, glycogen, and glucose. Thus, the present findings suggest a relation between hypotension during marked hypoxia, low energy charge, lactic acid accumulation in brain at high concentrations, and fetal brain injury. The ewes of hypoxic hypotensive fetuses received pentobarbital at lower doses than did those of fetuses that maintained blood pressure. This suggests that pentobarbital plays an important role in protecting the fetal brain from asphyxia by extending the hypoxic fetus's ability to maintain blood pressure in addition to reducing its brain metabolism.

Cerebrospinal fluid ions in metabolic acidosis in dogs: effects of acetazolamide

We hypothesized that, during isosmotic isonatremic HCl acidosis with maintained isocapnia in cisternal cerebrospinal fluid (CSF), acetazolamide, by inhibiting carbonic anhydrase (CA) in the central nervous system (CNS), should produce an isonatric hyperchloric metabolic acidosis in CSF. Blood and CSF ions and acid-base variables were measured in two groups of anesthetized and paralyzed dogs with bilateral ligation of renal pedicles during 5 h of HCl acidosis (plasma [HCO3-] = 11 meq/l). Mechanical ventilation was regulated such that arterial PCO2 dropped and CSF Pco2 remained relatively constant. In group I (control group, n = 6), CSF [Na+] remained unchanged, [HCO3-] and strong ions difference (SID) fell, respectively, 6.1 and 5 meq/l, and [Cl-] rose 3.5 meq/l after 5 h of acidosis. In acetazolamide-treated animals, (group II, n = 7), CSF [Na+] remained unchanged, [HCO3-], and SID fell 11 and 7.1 meq/l, respectively, and [Cl-] rose 7.1 meq/l. We conclude that during HCl acidosis inhibition of CNS CA by acetazolamide induces an isonatric hyperchloric metabolic acidosis in CSF, which is more severe than that observed in controls.

Role and mechanism of action of tamoxifen in premenopausal women with metastatic breast carcinoma

Tamoxifen was evaluated as initial hormone therapy for metastatic breast cancer in 85 premenopausal patients. Tamoxifen responders continued on tamoxifen, while tamoxifen failures and initial responders who later progressed were to receive ovarian ablation next. Of 74 evaluable patients, 5 had complete responses (CR) and 15 had partial responses (PR) while 12 remained stable (ST), giving response rates of 27% (CR + PR) or 43% (CR + PR + ST). Of the 23 patients who initially responded (CR + PR + ST) to tamoxifen but then progressed and received ovarian ablation alone, 15 are assessable. Nine (60%) responded (CR + PR + ST) to ovarian ablation. Sixteen patients who failed tamoxifen had ovarian ablation alone, and of 14 assessable patients 2 had ST while 12 progressed. Thus response to tamoxifen strongly predicted response to ovarian ablation (P = 0.021). Serial follicle stimulating hormone, prolactin, and estradiol levels suggested that tamoxifen does not act by induction of a "medical ovariectomy" or by alteration of prolactin levels in premenopausal patients.

Fetal growth retardation in rats from different levels of hypoxia

Three groups of pregnant Wistar rats were subjected to 3 different levels of hypoxia: 11.6, 10.7 and 9.0%, respectively. Pair-fed and ad libitum fed control groups were included to control for the reduced food intake due to hypoxia. Within the range studied, fetal body weights decreased with decreased oxygen availability. Liver weights were more, brain weights less markedly reduced than body weights. Pair-fed but normally oxygenated animals showed slight reductions in body and organ weights compared to ad libitum fed controls. The fetuses subjected to hypoxia showed a placental hypertrophy relative to their body weights, while the least hypoxic fetuses showed an absolute placental hypertrophy. Placenta-fetal body ratios that were 150% greater than those observed in control animals were documented. In contrast, the fetuses of food-deprived animals were associated with abnormally small placentas.

Brain injury from marked hypoxia in cats: role of hypotension and hyperglycemia

The present study identifies several factors that govern brain pathologic response to marked hypoxia. None of 13 cats exposed to 25 minutes of marked hypoxia (FiO2 = 3.4%; PaO2 = 17 +/- 3 mm Hg, S.D.) that maintained mean arterial blood pressure (MABP) greater than 65 mm Hg were brain injured after reoxygenation and long term survival. In contrast, 12 of 13 exposed to the same hypoxia but that experienced reductions in MABP less than 45 mm Hg for 4 +/- 1 minutes developed a pattern of brain injury closely resembling that of humans surviving in a persistent vegetative state after cardiorespiratory arrest. Higher serum glucose and lactate concentrations and lower blood pH values significantly correlated with development of hypotension during hypoxia. Four of 8 cats exposed to 21 minutes of marked hypoxia followed by 4 minutes of 100% N2 breathing that also led to hypotension similarly developed brain injury. Among the hypoxic/hypotensive cats the magnitude of the hyperglycemic response to hypoxia as modulated by 0, 1, or 2 days of preexposure fasting, strongly correlated with occurrence and extent of brain damage. Peak cisterna magna CSF lactate concentrations 10 to 30 minutes into recovery distinguished those animals that remained brain-intact (less than 13 mM) from those that developed brain damage (greater than 15 mM) with 100% accuracy. Seven cats developed delayed cardiogenic shock 3 to 12 hours into the recovery period. This outcome was predicted by blood pH values less than 6.70 shortly after resuscitation while all 27 surviving cats exhibited values greater than 6.80.

Topography of brain metabolites: rhesus monkey, goat, and cat

This report describes the detailed topographic distribution of metabolites (ATP, phosphocreatine, lactate, glycogen, and glucose) in the brains of three large animal species: rhesus monkey, goat, and cat. The findings demonstrated that adequate fixation of tissue metabolites can be achieved for most brain structures in those animals using in situ freezing. This method, which enables studies of metabolite concentrations in hemispheral and deep brain structures in large animals, can be used to examine correlations between changes in brain metabolism and brain injury in a variety of models of neurologic disease.

Hodgkin's Disease 1985

Most patients with Hodgkin's disease will present with painless lymphadenopathy; 50% will have some degree of mediastinal involvement. Diagnosis is made on finding Reed-Sternberg cells or atypical reticulum cells. Accurate staging is crucial and should be done jointly by medical and radiation oncologists. Treatment is by radiation or chemotherapy, or combinations of the two. Cure rates are high.

Autoimmune encephalomyelitis and hemorrhagic retinal disease in neonatal, infant, juvenile, and adult monkeys

Severe (24/24) and lethal (22/24) autoimmune encephalomyelitis was regularly induced in rhesus monkeys of all age groups from newborns to adults by a single injection of guinea pig spinal cord in complete Freund's adjuvant. Age dependency of the encephalomyelitis was manifested by a delayed onset and prolonged course in newborn monkeys. A hemorrhagic retinopathy usually accompanying the earliest CNS symptoms was observed in most of these monkeys. The most severe lesions were predominant in the cerebellum and brainstem of neonates, and in the cerebral hemispheres of older animals.

Failure to produce germinal matrix or intraventricular hemorrhage by hypoxia, hypo-, or hypervolemia

Our study with midgestational sheep fetuses failed to support a cause-and-effect relation between marked hypoxia with or without hypo- or hypervolemia and rapid surges of blood pressure and the development of germinal matrix or intraventricular hemorrhage. Twenty-nine percent of fetuses exposed to marked hypoxia concomitantly with manipulations of their blood volume and blood pressure developed widespread cerebral necrosis. However, despite this marked anoxic-ischemic brain injury, none developed any germinal matrix or intraventricular hemorrhage. Rapidly and markedly elevating the blood pressure in these fetuses despite the presumed presence of an impaired autoregulation and a probable elevation of their central venous pressure also failed to cause germinal matrix or intraventricular hemorrhage. Marked hypoxia accompanied by reductions in blood pressure brought about by blood withdrawal produced an 80% delayed fetal mortality but not a single instance of germinal matrix or intraventricular hemorrhage.

Hypoxic-ischemic cerebral necrosis in midgestational sheep fetuses: physiopathologic correlations

Thirty-eight midgestational sheep fetuses were exposed 120 min to marked hypoxia. The brains in eight that reduced their mean arterial blood pressure to less than 30 mm Hg were markedly damaged. In these same fetuses the serum lactic acid concentrations were elevated during exposure to hypoxia to excessively high values (greater than 15 mM) and remained elevated for a prolonged period during recovery. Twenty-one fetuses exposed to the same magnitude of hypoxia that maintained their blood pressure unchanged showed less marked elevations of serum lactate concentrations and remained brain-intact. Greater quantities of pentobarbital administered to the ewes during hypoxia seemed to protect the brain from hypoxia and this effect was dose-dependent. Exposure of midgestational sheep fetuses to marked hypoxia associated with reductions in cerebral blood flow due to decreased blood pressure and impaired cerebral autoregulation caused major focal cerebral necrosis.

Cyclophosphamide, doxorubicin, and cisplatin in the treatment of non-small cell bronchogenic carcinoma

One hundred and forty-three patients with unresectable non-small cell bronchogenic carcinoma were treated with combination chemotherapy consisting of cyclophosphamide, doxorubicin, and cisplatin (CAP). Objective responses were seen in 27.5% of 131 evaluable patients. Response rates for squamous cell carcinoma, adenocarcinoma, and large cell anaplastic carcinoma were 30.2% (13 of 43 patients), 28.0% (14 of 50), and 32.1% (nine of 28), respectively. The median survival time for responders with extensive disease was 33.0 weeks compared with 29.3 weeks for patients with stable disease and only 9.6 weeks for patients with disease progression. The survival advantage of patients responding to CAP relative to those who had disease progression during treatment is highly significant statistically (P = 0.0005). However, patients whose disease remained stable also had longer survival than those who had disease progression (P = 0.001), and their survival was not significantly different from that of responders (P = 0.19). The CAP chemotherapy regimen was generally well-tolerated, although acute gastrointestinal symptoms were common. Our results indicate that CAP chemotherapy can cause tumor regression in patients with non-small cell bronchogenic carcinoma and may extend the survival of responding patients.

Hemodynamic response to profound hypoxia in intact rhesus monkeys

Respiring rhesus monkeys with 2.5 or 4.5% oxygen greatly decreased their cardiac contractility, stroke volume and blood pressure but altered their total peripheral vascular resistance only slightly and inconsistently. All monkeys exposed to 15 minutes and 2 of 4 exposed to 30 minutes of hypoxia recovered and survived without brain injury. Though all animals recovered full cardiovascular function immediately after they were reoxygenated, 2 respired with 4.5% oxygen for 30 minutes began showing declines in blood pressure after a delay of 1 to 2 hours and both subsequently died in shock. Their reductions in blood pressure were associated with reductions in cardiac contractility and stroke volume. The hypotension the animals exhibited both during hypoxia and during development of shock afterwards resulted from pump failure rather than a reduced vascular resistance or an inadequate venous return.

Tamoxifen therapy in premenopausal patients with metastatic breast cancer

Tamoxifen was evaluated in a phase II trial as initial hormonal therapy in premenopausal patients with metastatic breast cancer. The study design was such that responders remained on tamoxifen therapy; those who initially or subsequently progressed went on to ovarian ablation either by surgery or irradiation. Of 42 evaluable patients treated with tamoxifen, three had complete responses (CR), ten had partial responses (PR), and four remained stable (ST), giving total response rates of 32% (CR + PR) or 41% (CR + PR + ST). Among the 18 patients with positive estrogen (ER) or progesterone (PgR) receptors, there were eight responders, but only one responder (ST) in the nine patients with negative ER or PgR. Of the 25 patients who failed to respond to tamoxifen, 13 underwent ovarian ablation; all failed to respond. These 13 included four patients who were ER positive or equivocal and PgR positive or unknown. Nine tamoxifen responders (CR + PR + ST) have subsequently progressed; of these, eight have gone on to ovarian ablation. Six of these eight have responded (five PR and one ST) to ovarian ablation, and one has failed to respond. Thus, steroid receptors generally predicted a patient's response to tamoxifen therapy, but response to tamoxifen also strongly predicted a patient's subsequent response to ovarian ablation.

Fetal heart rate and blood pressure during prolonged partial asphyxia in the rhesus monkey

Fetal heart rate (FHR) and fetal blood pressure (FBP) were recorded continuously in 20 anesthetized fetal monkeys near term while their oxygenation was progressively decreased by a stepwise reduction in uterine blood flow. Fetal blood was sampled periodically from the carotid artery and analyzed for pH and PO2. Hemoglobin saturation with oxygen (S) was derived from nomogram. During the study period, uterine contractions were either minimal or absent. FHR remained constant as long as S was greater than 55%. Below that it began to decline by 0.34%/% saturation. When S was less than 31%, FHR fell by 0.93%/% saturation. The correlation between FHR and PO2, and FHR and pH, was less consistent. Arterial FBP was maintained over the entire range of pH, PO2, and S. It is concluded that, under the conditions described, an unequivocal decrease in mean FHR signals a substantial reduction in the availability of O2 to the fetus.

Auditory evoked potentials and auditory behavior following prenatal and perinatal asphyxia in rhesus monkeys

Two types of asphyxia were studied in monkeys, total asphyxia during mid-pregnancy (94--98 days gestation) and combined partial and total axphyxia at term (165 days gestation). Auditory evoked potentials and the acquisition of 2 auditory discrimination tasks were studied in asphyxiated animals as well as in group of controls. The brains of all asphyxiates were examined histologically. No auditory discrimination deficit was found in the asphyxiated animals; however, the auditory evoked potentials differentiated between control and asphyxiated animals, especially those with verified inferior colliculus damage.

Neurologic and cardiovascular effects of hypotension in the monkey

Thirty monkeys were exposed to controlled systemic hypotension of different magnitudes and duration to determine factors leading to brain injury or cardiovascular failure. Fourteen monkeys developed brain injury. Of these, 6 survived indifinitely and 8 were sacrificed or died within 12-62 hours due to neurologic deterioration accompanied by respiratory failure. Sixteen animals did not develop brain injury, but 9 of these died within 24 hours from documented cardiovascular failure with the remaining 7 survived indefinitely. A highly reproducible threshold for the development of brain injury was found at a mean arterial blood pressure (MABP) of 25 mm Hg. Maintenance MABP was less than or equal to 25 mm Hg in 13 of 14 lesioned monkeys and greater than 25 mm Hg in 15 of 16 non-lesioned monkeys. Maintenance MABP averaged 20.1 +/- 1.1 mm /g in lesioned and 32.1 +/- 1.7 mm Hg in non-lesioned animals (p less than 0.001). Among the non-lesioned animals, death from delayed cardiovascular failure ensued when MABP was maintained between 27 and 35 mm Hg for 90 min or longer. Animals exposed to this range of hypotension for less than 90 min or to MABP exceeding 35 mm Hg for as long as 3 h survived intact. EEG changes occurring during hypotension most accurately predicted neurologic outcome. The threshold MABP required to produce cerebral electric silence was 21-22 mm Hg. Monkeys developing marked brain injury had greater than 25 minutes of EEG flattening, while slightly injured animals had it for 5-15 minutes and those without injury for less than 5 min. Changes in acid-base state, common carotid artery blood flow, and cerebral uptake of glucose and oxygen during hypotension also correlated with neurologic and cardiovascular outcome. Hypoxemia and hypercarbia were not contributory factors in the production of brain injury in this study.