PubMed Health⌕ Search

Biomedical subjects

R G Hoffmann

Publications and source records attributed to R G Hoffmann.

At least 109 records · Page 6Linked to original sources
PubMed1987

Institution-specific versus published in vitro antimicrobial susceptibility data in making formulary decisions.

The results of susceptibility testing of 549 isolates of gram-negative organisms to 17 antimicrobial agents were compared with published reports of the sensitivity of those organisms to those agents. All gram-negative bacilli isolated from cultures obtained from hospitalized patients during a three-month period were preserved for antimicrobial sensitivity testing. Standard Kirby-Bauer disk diffusion susceptibility tests were performed using 17 broad-spectrum antimicrobial agents that either were included in the hospital formulary or were being considered for inclusion. Organisms were recorded as being sensitive or resistant to each drug, and the results were compared with the published results of in vitro sensitivity studies. When the results of actual antimicrobial sensitivity testing varied from published results, the discordant results were assigned a ranking of 1 to 4 based on the percentage difference. In 34 of 77 drug-organism pairs tested, the results of susceptibility testing differed by more than 10% cumulative susceptibility from published values; 26 of these represented instances in which the results of actual testing were at least 10% less than published values. For seven of the antimicrobial agents that were being considered for inclusion in the hospital formulary, results indicating unexpectedly suboptimal activity against institutional pathogens were a determinant in eliminating the agents from further consideration. In vitro testing of antimicrobial susceptibility of local pathogens can be a better method of predicting the susceptibility of such pathogens to new antimicrobial agents than relying on published susceptibility data. Pharmacy and therapeutics committees should consider testing prevalent institutional pathogens for susceptibility to all antimicrobial agents that are proposed additions to the formulary.

Aminoglycosides↗
PubMed1986

Family trait analysis: a case-control study of 43 women with endometriosis and their best friends.

Analyses of lineage patterns show that for 43 women with endometriosis who reported that other family members have the disease, the vast majority of these familial cases involve the maternal lineage (79% to 93%). Of these women 34.9% of their mothers and 21.2% of their sisters were affected. With use of these rates, expected rates for first-degree relatives in a general population of women with endometriosis were determined. These rates were 6.2% and 3.8%, respectively; in combination, these rates yield an overall risk of 4.9% for first-degree relatives. Prior studies estimated this overall risk to be 6.9%; however, z scores determined that these rates do not differ statistically. Rates for second-degree maternal relatives are reported for grandmothers and aunts (0.4% compared to 3.1%, respectively), thus expanding results of former studies. In combination, an overall risk of 1.9% is estimated for second-degree relatives, as measured.

Adult↗
PubMed1986

A randomized study of adjuvant chemotherapy for cancer of the upper aerodigestive tract.

A prospective, randomized trial of induction chemotherapy in advanced squamous cell carcinomas of the upper aerodigestive tract (UAD) was conducted between July 1979 and September 1982. Eighty-three patients with locally advanced Stage III-IV tumors received standard treatment (STD RX; defined as preoperative irradiation and radical excision or irradiation alone), or induction chemotherapy (CTX) followed by STD RX. Chemotherapy consisted of two cycles of bleomycin (30 units/day by continuous infusions Days 1-4), cyclophosphamide (200 mg/m2 IV Days 1-5), methotrexate (30 mg/m2 Days 1 + 5), and 5-fluorouracil (400 mg/m2 IV Days 1-5). Response to CTX was complete in 2 and partial (greater than 50% reduction) in 27; the overall response rate was 68%. Tumor clearance was documented in 30/40 STD RX patients at completion of irradiation and/or surgery and in 24/43 CTX patients (17/29 responders, 7/14 non-responders). Freedom from local-regional disease was noted at 2 years in 53% STD RX and 35% CTX patients (p less than .06). CTX patients had a higher proportion of local-regional persistence and recurrence. The difference was apparent only in the subset of patients treated with primary irradiation; local-regional control following irradiation and surgery was equal in STD RX and CTX groups. Survival at 2 years was 43% STD RX and 31% CTX. Disease-free survival in those with clearance was 64% STD RX and 59% CTX. Induction chemotherapy did not improve tumor clearance or survival in this series. Caution regarding local-regional control with CTX and primary irradiation is noted.

Bleomycin↗
PubMed1986

Prevalence survey of infections and their predisposing factors at a hospital-based nursing home care unit.

A prevalence survey was performed at a Veterans Administration nursing home care unit to detect the frequency, demographics, features, and potential risk factors associated with infections, compare different methods for calculating infection rates, and compare prevalence data with routine physician reporting of infections during a one-month period. In 176 evaluable residents, 22 nursing home-acquired infections were detected, with rates of 12.5% by infections per residents at risk, and 4.6% by infections per 1000 resident-days. Fifty percent of these infections (11 of 22) involved the urinary tract, seven of which were associated with indwelling catheters. Factors potentially associated with increased overall infection rates included immobility (P less than .02), acute-care hospitalization in the 28 days preceding the study (P less than .01) and antibiotics given preceding the infection (P less than .001). An indwelling urinary catheter (P less than .01) potentially was associated with an increased urinary tract infection rate. During the concurrent period, routine physician reporting of infection detected four of the 22 infections (18%) that were identified by the survey. These findings suggest that physician reporting of infection underestimates infection risk as compared with conventional surveillance practices, and that hospital-based care units may have infection problems more similar to acute-care hospitals than to community nursing homes. Identification of potential risk factors is critical in planning preventive practices based on institution-specific needs.

Aged↗
PubMed1986

Total peripheral resistance during cardiac tamponade: adrenergic and angiotensin roles.

During progressive cardiac tamponade in conscious dogs, cardiac output falls continuously while arterial blood pressure is maintained until cardiovascular decompensation by increases in total peripheral resistance (TPR). Plasma renin activity (PRA) is known to increase at decompensation. We hypothesized that the increase in TPR during cardiac tamponade was mediated by alpha-adrenergic and renin-angiotensin mechanisms. Twelve adult dogs were instrumented to measure cardiac output (electromagnetic flow probe), aortic and right atrial blood pressures, and intrapericardial pressure (IPP). TPR was calculated as the conscious euvolemic animals underwent cardiac tamponade induced by intrapericardial saline infusion at 20 ml/min. Six dogs underwent cardiac tamponade in the control condition (no medications) and during independent alpha- and beta-adrenergic and angiotensin-converting enzyme (ACE) inhibition. PRA and angiotensin II (ANG II) were measured during control tamponade. We found that TPR increased continuously to levels of greater than 200% of base line as IPP rose during cardiac tamponade (P less than 0.01). This increase in TPR was unaffected by beta-adrenergic or ACE blockade but was blunted by alpha-adrenergic blockade. PRA and ANG II increased only at decompensated tamponade (P less than 0.05) when arterial blood pressure had fallen by 30%. These changes in PRA and ANG II during tamponade were not altered by beta-blockade in six separate animals. We conclude that cardiac tamponade stimulates renin release and ANG II generation by a non-beta-receptor-mediated mechanism. The increase in TPR during cardiac tamponade is primarily dependent on alpha-adrenergic mechanisms, with a limited late contribution from the renin-angiotensin system.

Angiotensin II↗
PubMed1986

Pneumococcal vaccine immunization of patients with renal impairment.

The immunogenicity of the polyvalent pneumococcal vaccine was studied in renal allograft recipients and dialysis patients. There was no significant overall difference in the antibody response of the allograft recipients compared to control subjects at 1 month following immunization. Chronic hemodialysis patients had significantly lower postvaccination antibody levels for 6 of 12 serotypes. Better graft function in the allograft recipients correlated positively with higher antibody levels. Azathioprine and prednisone in dosages employed had no consistent effect on antibody response. No deterioration of renal function ascribable to the vaccine was observed. Patients were sampled at 1, 2, and 3 1/2 years following immunization. Geometric mean titers (GMT) were calculated for all the serotypes per group for each time of sampling. There was a significant decrease with time in antibody GMTs for all the groups (P less than 0.01). Chronic hemodialysis patients had significantly lower GMTs than control subjects and allograft recipients at 1, 2, and 3 1/2 years postimmunization (P less than 0.05). The 3 1/2 years postimmunization antibody levels were very low in dialysis patients, suggesting that reimmunization of these patients may be required.

Adult↗
PubMed1986

Early diagnosis of acute postoperative renal transplant rejection by indium-111-labeled platelet scintigraphy.

A prospective evaluation of 111In-labeled platelet scintigraphy (IPS) for the early diagnosis of acute postoperative renal transplant rejection (TR) was undertaken. The results of IPS were compared with in vitro biochemical tests, the clinical finding of graft tenderness, and combined [99mTc]DTPA and [131I]orthoiodohippurate scintigraphy. With a sensitivity of 0.93 and a specificity of 0.95, IPS provided otherwise unavailable diagnostic information. Furthermore, postoperative IPS was a good predictor of long-term allograft survival.

Acute Disease↗
PubMed1985

Combined methotrexate and high-dose vincristine chemotherapy with radiation therapy for small cell bronchogenic carcinoma.

The addition of methotrexate to a previously described regimen of cyclophosphamide, Adriamycin (doxorubicin), and high-dose vincristine (VAC) was tested in 50 evaluable patients with small cell bronchogenic carcinoma. Prophylactic whole brain radiation therapy was given during the first chemotherapy course and consolidation radiation therapy was given to the mediastinum and primary site after achieving partial or complete remission. The addition of methotrexate did not improve the incidence of complete remission as compared to a previous regimen without it. The addition of radiation therapy improved the local control rate. The high-dose vincristine in this and a previous CAV study improved the incidence of complete remission in both limited and extensive disease presentation as compared with the authors' previous experience and induced an acceptable and reversible neurotoxicity. Moderate dose consolidation radiotherapy to the lung primary and mediastinum was effective in improving local control. The distinction between limited and extensive disease was found to be vague, as 22% of the patients could be shifted from one group to the other depending on definition. The evaluation of the various staging procedures indicates that bone scan gave a small number of truly abnormal tests. Isotopic brain and liver-spleen scan could be duplicated by computerized axial tomography (CAT). CAT scan of abdomen disclosed unexpected extension to the retroperitoneal nodes and adrenals. It is concluded that radionuclide studies of brain, liver-spleen, and bone can be eliminated and can be replaced by CAT scan of brain, chest, and abdomen. Site of recurrence indicate that most intrathoracic recurrences took place outside the radiation therapy field and in the pleural space. An incidental finding was the high incidence of intramedullary spinal cord recurrence.

Adult↗
PubMed1985

Alterations in intravascular volume affect the relation between right ventricular diastolic collapse and the hemodynamic severity of cardiac tamponade.

Right ventricular diastolic collapse has been demonstrated to be a sensitive and specific sign of cardiac tamponade. Because the shape and position of the right ventricular wall are related to the relative pressures within the pericardial space and the right ventricular chamber, the usefulness of right ventricular diastolic collapse as a marker of cardiac tamponade may be influenced by intravascular volume and right heart filling pressures. This study was undertaken to determine the effects of volume loading and hemorrhage on the point within the hemodynamic progression of cardiac tamponade at which right ventricular diastolic collapse first appears. Five unanesthetized, chronically instrumented dogs were studied with two-dimensional echocardiography during 41 episodes of cardiac tamponade induced by the intrapericardial infusion of warm saline solution. Intravascular volume was adjusted before cardiac tamponade to a hypovolemic, euvolemic or hypervolemic state using saline solution and dextran infusion or hemorrhaging to achieve the prescribed mean right atrial blood pressure. The measurements recorded during each episode of cardiac tamponade were right atrial blood pressure, aortic blood pressure, cardiac output (by electromagnetic flow meter), heart rate and intrapericardial pressure. When compared with the euvolemic state, the onset of right ventricular diastolic collapse in volume contraction occurred at a lower intrapericardial pressure (with a lower aortic blood pressure and cardiac output), whereas in volume expansion it occurred at a higher intrapericardial pressure (with a higher aortic blood pressure and cardiac output). Volume expansion delayed the decrease in hemodynamic variables during cardiac tamponade in this canine model.

Animals↗
PubMed1985

Chronic progressive multiple sclerosis: double-blind controlled study of plasmapheresis in patients taking immunosuppressive drugs.

Fifty-four patients with chronic progressive multiple sclerosis received prednisone plus oral low-dose cyclophosphamide and either true plasmapheresis (PP) or "sham" PP weekly for 20 weeks in a double-blind controlled study. Immunosuppressive drug therapy alone (sham PP group, n = 29) was associated with improvement (greater than or equal to one step in Kurtzke Disability Status Scale [DSS]; mean change of 1.5) in 8 and stabilization of MS in 18 patients, with this status sustained in 23 patients at follow-up, 11 months after entry. In contrast, 14 of 26 patients who received "true" PP improved (greater than or equal to one step in DSS; mean change of 2.6), and 11 more were stable, with these changes sustained in 23 of 26 patients at follow-up. These differences, overall, between the PP and sham PP groups were significant at p less than 0.007.

Adult↗
PubMed1985

A longitudinal study of marijuana effects.

One hundred regular marijuana users volunteered to be extensively interviewed in 1968-1970, and 97 were located and reinterviewed 6 to 8 years later. As part of each interview the subjects filled out a checklist review of 105 effects of marijuana. This report focuses on the differential patterns of effects found at the two time intervals. Scores on groupings of items were examined for changes over time. Reports of sensory and hallucinatory items dropped substantially. Reports of appetite effects, sex effects, and intoxication effects on sleep remained stable. Reports of cognitive effects, mood effects, and aftereffects on sleep appeared to be shifting from desirable to undesirable, with the frequency of desirable effects dropping while frequency of undesirable effects remained the same.

Adolescent↗
PubMed1985

Overweight and obesity in hypertension.

Many studies have shown body weight to correlate with blood pressure and the prevalence of hypertension, but few have examined whether the correlation between overweight and hypertension holds at higher levels of blood pressure. This study evaluated the degree of overweight and hypertension among 1795 adult men and women with hypertension (diastolic pressure greater than or equal to 90 mmHg) who were referred to a community-based hypertension clinic in Milwaukee during a five-year period. Using a nomogram for body mass index (BMI), we found that more than one-third of the subjects were overweight and over one-third were obese, with black and white females showing slightly higher indices than males. There was a trend for BMI to decline with age in both ethnic groups. Among the group not on antihypertensive medication (1344 patients), there was no correlation between BMI and blood pressure. Blood pressure correlated positively with age but BMI showed an opposite trend. After BMI was corrected for age, the correlation was the same and tended to be in the negative direction. A striking trend observed is that the higher the BMI, the greater the percentage of subjects with diastolic pressures between 90-104 mmHg. These results do not necessarily contradict a possible role of obesity in hypertension. Rather, they confirm the high prevalence of overweight among hypertensives and suggest that a large proportion of obese hypertensives tend to have a relatively mild pressure elevation. In view of the known hypotensive effect of weight reduction, the likelihood of reducing blood pressure to normotensive levels in this group by diet is stressed.

Adult↗
PubMed1984

Relationship of body fat topography to insulin sensitivity and metabolic profiles in premenopausal women.

The relationship of body fat distribution to metabolic profiles was determined in 80 healthy premenopausal white women of a wide range of obesity levels [percentage of ideal body weight (% IBW) 92-251]. Distribution of fat between the upper and lower body was assessed from the waist/hips girth ratio (WHR), which varied from 0.64 to 1.02. In 23 women, in vivo insulin sensitivity was also determined from the steady-state plasma glucose (SSPG) level at comparable insulin levels of approximately 100 microU/mL attained by the intravenous infusion of somatostatin, glucose, and insulin. Increasing WHR was accompanied by progressively increasing fasting plasma insulin levels (r = 0.47, P less than 0.001), insulin and glucose areas after glucose challenge (r = 0.53, P less than 0.001; r = 0.50, P less than 0.001, respectively) and fasting plasma triglyceride concentrations (r = 0.48, P less than 0.001). Obesity level was similarly correlated with these metabolic indices. Partial and multiple regression analysis and analysis of variance with a linear contrast model revealed that the effects of body fat topography were independent of, and additive to, those of obesity level. Within obese subjects alone (%IBW: 130), %IBW had no predictive value, but WHR remained a significant predictor of plasma glucose, insulin, and triglyceride concentrations. The WHR also correlated with the plasma cholesterol level, but this association was largely dependent on its relationship to %IBW. Both WHR and %IBW correlated with the insulin resistance index, SSPG (r = 0.60, P less than 0.01; r = 0.61, P less than 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1984

Alpha subunit and human chorionic gonadotropin in normal pregnancy and gestational trophoblastic disease.

The reported incidence of gestational trophoblastic disease is an order of magnitude higher in Nigeria than in the United States. Sera from a total of 283 pregnant black patients, 138 United States and 148 Nigerian pregnant patients, were analyzed for their serum levels of alpha subunit and human chorionic gonadotropin (hCG). The patterns of hCG secretion were similar in the two populations during normal pregnancy. However, the level of alpha subunit was persistently higher in Nigerian women than in comparable pregnant United States patients. A statistically significantly higher alpha subunit level in the Nigerian patients was found only in the ten- to 13-week gestational period (P less than .005). The higher level of alpha subunit in pregnancy in Nigerian women may signal a population of trophoblastic cells which may be at higher risk for malignancy development in the Nigerian woman.

Black People↗
PubMed1983

The relationship between vasectomy and angiographically determined atherosclerosis in men.

Long-term prospective studies in monkeys have shown that vasectomy is associated with an increase in atherosclerotic disease. The purpose of the present investigation is to evaluate whether vasectomy in men is associated with atherosclerotic disease in the coronary arteries. In this study information was obtained on the vasectomy status in a series of 7,420 men who had previously been referred for coronary angiography because of cardiovascular symptomatology and have been followed for as long as 9 years to evaluate coronary artery bypass surgery and the natural history of the disease. It was found that 5.0% had a vasectomy prior to angiography. Two different data analysis procedures were used to determine whether the vasectomized men had a greater degree of angiographically determined coronary occlusive disease than the nonvasectomized men. Subgroups with minimal and extensive coronary artery disease were also analyzed. Results of all analyses show that the vasectomized men did not have more coronary occlusive disease. Possible patient selection biases in this study are discussed.

Adult↗