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Biomedical subjects

R Weber

Publications and source records attributed to R Weber.

At least 325 records · Page 18Linked to original sources
PubMed1990

Undifferentiated carcinomas of the major salivary glands.

Undifferentiated salivary carcinomas are defined as primary epithelial malignant neoplasms that are devoid of any phenotypic expression by light microscopy that would allow them to be otherwise classified. A clinicopathologic study of sixteen so-defined carcinomas of the major salivary glands is presented. The carcinomas are unquestionably high-grade malignant neoplasms. Ten of the sixteen patients were dead because of their disease within 4 1/2 years of histologic diagnosis. Cell size and ultrastructural features have little bearing on prognosis. The single most important clinicopathologic factor relating to patient outcome is size of the primary neoplasm. All patients with carcinomas larger than 4 cm died, and these carcinomas had nearly two times the incidence of perineural invasion, extrasalivary extension, and locoregional failure of control.

Aged↗
PubMed1990

Corticotropin releasing hormone mRNA is elevated on the afternoon of proestrus in the parvocellular paraventricular nuclei of the female rat.

We investigated changes during the estrous cycle in cellular levels of corticotropin-releasing hormone (CRH) mRNA in parvocellular neurons of the hypothalamic paraventricular nucleus, using in situ hybridization. Intact female rats with 4 day cycles were sacrificed at 11 different times during the cycle at 09.00 h and 16.00 h on each day, with additional collection times at 14.00 h, 18.00 h, and 20.00 h on the day of proestrus. Twelve microns coronal sections of fresh-frozen brains were made through the paraventricular nuclei (PVN) and placed on gelatin-coated slides. A 48 base oligodeoxynucleotide probe complementary to the coding region for rat CRH was used to measure CRH mRNA. There was a sharp increase (P less than 0.01) in CRH mRNA in the ventral PVN between 14.00 and 16.00 h on the day of proestrus, at the approximate time of the ovulatory surge. Following this rise, there was an even larger decline (P less than 0.01) between P 16.00 h and P 20.00 h. Levels of CRH mRNA did not change greatly on other days of the cycle, nor were there significant changes in the dorsal PVN. Given the known effects of CRH on GnRH secretion, these changes occur at a time when they could serve to modulate the midcycle luteinizing hormone (LH) surge.

Animals↗
PubMed1990

Differences in air ambulance patient mix demonstrated by physiologic scoring.

Severity of illness or injury should be the primary justification for aeromedical transport. To determine whether differences in patient severity were detectable in air transport programs, helicopter-transported patients were examined by three established physiologic scores: the Trauma Score, the Acute Physiology and Chronic Health Evaluation Score, and the Rapid Acute Physiology Score. These scores were obtained prospectively on 1,868 consecutive patient transfer requests from six air medical services for periods ranging from two to six months. A patient meeting strict physiologic criteria was considered critically ill. Overall, 42.6% of the patients (range, 34.8% to 53.3%) were considered critically ill. Patients transported from inpatient hospital units and patients with cardiac disease were less likely to be critically ill than those transported emergently from scenes of accident or from emergency departments. There were also significant differences between programs with regard to the percentage of critically ill patients transported. This study suggests that physiologic scoring may be useful in comparing air ambulance programs and that a majority of patients transported by these services may not be critically ill.

Aircraft↗
PubMed1990

A concerted effort to boost Medicare reimbursement in North Carolina.

In summary, a group of hospital-based air medical services in North Carolina were able to work cooperatively to develop a one-day seminar for their Medicare intermediary. This utilized personnel from all of the participating hospitals in an educational framework designed to enhance understanding of the uniqueness of air medical services and their differences from ground transport services. The benefits of this effort are being seen on a regular basis through enhanced Medicare payment of claims.

Aircraft↗
PubMed1990

APACHE II scoring in the injured patient.

The purpose of this study was to measure the predictive power of Acute Physiology and Chronic Health Evaluation (APACHE II) with respect to mortality in a group of seriously injured patients and to compare this predictive power with that of the Trauma Score (TS) and the Injury Severity Score (ISS). Six hundred ninety-one helicopter-transported patients were studied. Individual logistic regressions demonstrated that all three scores had significant predictive power when considered individually (TS chi 2 = 136, p less than .0001; APACHE II chi 2 = 171, p less than .0001; ISS chi 2 = 109, p less than .0001). In addition, each severity score added significantly to the predictive power in a stepwise logistic regression (TS chi 2 = 15, p less than .0001; APACHE II chi 2 = 45, p less than .0001; ISS chi 2 = 15, p less than .0001). Areas under the receiver operating curves for the three scores were not significantly different (TS 0.8116, SD 0.0245; APACHE II 0.8515, SD 0.0204; ISS 0.7967; SD 0.0223). APACHE II is a good predictor of mortality, and its predictive power is complemented by TS and ISS.

Adolescent↗
PubMed1990

Rapid acute physiology scoring in transport systems.

A multi-institutional study was undertaken to define the predictive power for mortality of the Rapid Acute Physiology Score (RAPS) in a large and diverse group of transported patients. RAPS is a truncated version of the Acute Physiology and Chronic Health Evaluation (APACHE II) score that uses definitions and weighting consistent with APACHE II, but is modified to provide a consistent score just before transport, just after transport, and to use the most deranged (worst) physiologic values during the initial 4 h after arrival at the receiving hospital. During an 8-month period, 1,927 patients transported by six helicopter emergency medical service programs were studied. Over 97% (1,881) of the patients had RAPS obtained before and after transport to the receiving hospital and 92.6% (1,785) had APACHE II scoring completed after hospital admission. Receiver operating curves demonstrate similar predictive power for RAPS and APACHE II (both based on the most deranged physiologic values during the initial 24 h after admission). Before- and after-transport RAPS were also highly predictive of mortality. RAPS appears to be a reliable and highly predictive measure of patient severity/physiologic stability before and after transport to critical care.

Adult↗
PubMed1990

Prognostic score for Pneumocystis carinii pneumonia.

Sixty episodes of Pneumocystis carinii pneumonia in 59 patients were evaluated for risk factors predicting fatal outcome within 14 days after bronchoscopy. We found significantly higher values for serum lactate dehydrogenase (p less than 0.001), alveolar-arterial oxygen difference (p less than 0.001) and percentage of bronchoalveolar lavage neutrophils (p less than 0.001) in patients dying within 14 days, but there was considerable overlap of these variables between the two groups. Using a score system combining the three parameters allowed however an excellent discrimination between the two groups.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Four-hour measurement of urinary iron excretion after deferoxine treatment: a rapid, simple method for study of iron excretion.

In a group of 56 patients being evaluated for iron storage disease, all of whom underwent liver biopsy with quantitative measurement of liver iron concentration, urinary excretion of iron was measured following intramuscular injection of deferoxamine (10 mg/kg body weight). Urine was collected in two portions, 0-4 h and 4-24 h after deferoxamine administration. Iron excretion in the first 4 h was closely correlated to that over the entire 24-h period (r = 0.88, p less than 0.0001, 95% confidence interval = 0.80-0.93), indicating that the 4-h deferoxamine urinary excretion test can be adapted readily to an outpatient clinical setting, helping to insure complete and accurate urine collections. Correlation of 0- to 4-h urinary iron excretion and quantitative liver iron (r = 0.335), although higher than for the full 24 h (r = 0.192), was not sufficient to accurately predict hepatic iron concentration in the individual patient.

Deferoxamine↗
PubMed1989

Co-infection with human immunodeficiency virus-type 1 (HIV-1) and cytomegalovirus in two intravenous drug users.

A mononucleosis-like illness is frequently recognized retrospectively as the first manifestation of infection with human immunodeficiency virus-type 1 (HIV-1). This acute but transient retroviral syndrome may include symptoms such as malaise, fever, sweats, myalgia, arthralgia, maculopapular rash, diarrhea, and lymphocytic meningitis. We observed two intravenous drug users who developed a severe, febrile illness with subsequent oral thrush (one also had biopsy-proven esophageal candidiasis). Both patients had weight loss, arthralgia, myalgia, and fatigue. These symptoms occurred two weeks after needle-sharing and persisted for 7 weeks in one patient and 10 weeks in the other. Both patients had serologic evidence for both acute HIV-1 and cytomegalovirus infection. Cytomegalovirus enhances HIV-1 replication in vitro, presumably by stimulating HIV-1 gene expression. Thus, the observed syndrome suggests that this viral interaction may be clinically significant because it appears to cause severe additional morbidity, which is not typical for primary infection with HIV-1. After 6 months of follow-up, one patient is completely asymptomatic but shows markedly reduced CD4+ lymphocytes. The other patient developed persistent lymphadenopathy after the acute illness, but is feeling well 21 months after infection.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Histones have high affinity for the glomerular basement membrane. Relevance for immune complex formation in lupus nephritis.

An effort has been made to integrate insights on charge-based interactions in immune complex glomerulonephritis with nuclear antigen involvement in lupus nephritis. Attention was focussed on the histones, a group of highly cationic nuclear constituents, which could be expected to bind to fixed anionic sites present in the glomerular basement membrane (GBM). We demonstrated that all histone subfractions, prepared according to Johns (4), have a high affinity for GBM and the basement membrane of peritubular capillaries. Tissue uptake of 125I-labeled histones was measured by injecting 200 micrograms of each fraction into the left kidney via the aorta and measuring organ uptake after 15 min. In glomeruli isolated from the left kidneys, the following quantities of histones were found: f1, 13 micrograms; f2a (f2al + f2a2), 17 micrograms; f2b, 17 micrograms; and f3, 32 micrograms. Kinetic studies of glomerular binding showed that f1 disappeared much more rapidly than f2a. The high affinity of histones (pI between 10.5 and 11.0; mol wt 10,000-22,000) for the GBM correlates well with their ability to form aggregates (mol wt greater than 100,000) for comparison lysozyme (pI 11, mol wt 14,000), which does not aggregate spontaneously bound poorly (0.4 micrograms in isolated glomeruli). The quantity of histones and lysozyme found in the isolated glomeruli paralleled their in vitro affinity for a Heparin-Sepharose column (gradient elution studies). This gel matrix contains the sulfated, highly anionic polysaccharide heparin, which is similar to the negatively charged heparan sulfate present in the GBM. Lysozyme eluted with 0.15 M NaCl, f1 with 1 M NaCl, and f2a, f2b, and f3 could not be fully desorbed even with 2 M NaCl; 6 M guanidine-HCl was necessary. Two further findings of great relevance for the concept of induction of immune complex glomerulonephritis by histones were: (a) glomerular-bound histone was accessible for specific antibody given intravenously; and (b) prior binding of histones promoted glomerular deposition of anionic antigens, as could be shown with ssDNA fragments. These data justify the proposal that glomerular deposition of histones can induce immune complex formation, start an inflammatory process, and produce tissue damage.

Animals↗
PubMed1989

[Aspecific and lymphocytic interstitial pneumonia in HIV infections].

The results of 115 bronchoscopic examinations and one autopsy in 105 adults with HIV-infection and pulmonary complications are presented. Whereas 51.7% of the events were caused by Pneumocystis carinii pneumonia (PCP), nonspecific interstitial pneumonitis (NIP) without evidence of an infectious or neoplastic condition was the second most frequent diagnosis in 14 patients (12.1%), four of whom exhibited features of lymphocytic interstitial pneumonia (LIP). The clinical, radiological and prognostic aspects of NIP/LIP, which are very similar to those of PCP, and the possible pathogenesis are discussed. The importance of an adequate diagnostic pulmonary workup is emphasized. We suggest classifying patients with NIP/LIP as stage IV E (CDC) and evaluating the efficacy of a treatment with azidothymidine (AZT) in a controlled clinical study.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Clinical counseling and management of HIV-positive patients--secondary individual prophylaxis in patients with HIV infection].

In patients with HIV infection, secondary prophylaxis should prevent HIV-associated complications caused by opportunistic infections and psychosocial morbidity. This overview presents the possibilities of chemoprophylaxis and control of transmission to prevent opportunistic and non-opportunistic infections. Indications for immunization in HIV-positive patients are also discussed. Both medical treatment and psychological and social support are equally important for optimal patient care.

Anti-Bacterial Agents↗
PubMed1989

Energy production, intracellular amino acid pools, and protein synthesis in chronic renal disease.

Intracellular glycolytic regulating enzyme activities, pyruvate kinase (PK) and phosphofructokinase (PFK), adenylate kinase (AK), energy charge (Ech), free amino acids (ICAA), and protein synthesis (PS) were measured in polymorphonuclear leukocytes--used as a cell model--in 62 adults and 12 children with chronic renal failure, and 66 normal adults and 21 children as comparison controls. In normal subjects, children had significantly lower enzyme activities and cell amino acid levels but similar Ech and higher PS than adults. ICAA concentrations were significantly higher than plasma amino acid concentrations (PAA) in both groups, and the PAA were not correlated with, nor indicative of, the ICAA concentrations. The variance (R2) in PS could be largely accounted for by a combination ("set") of six ICAA, as determined by multivariate analysis. The sets differed in children vs adults, suggesting that different proteins were being synthesized. In the uremic patients, reduced PF, PFK, Ech, most ICAAs and PS were indicative of cellular malnutrition. For the uremic adults, the abnormalities in cell metabolism were modified by therapy--nondialyzed uremics being worst, CAPD patients best and approximately normal, and hemodialyzed intermediate. The uremic CAPD children had reduced, PK, PFK, AK, most ICAA, and PS. Ech was increased. Cellular malnutrition in children with chronic renal failure may contribute to their poor growth.

Adolescent↗
PubMed1989

Suppression of polyclonal B cell proliferation mediated by supernatants from human myeloma bone marrow cell cultures.

For functional characterization and semi-quantitative estimation of soluble regulator factors influencing polyclonal B cell proliferation and differentiation, we established two assays. One of the assays measures enhancement or inhibition of proliferation from purified human spleen B lymphocytes, and the other one the effect of soluble factors on CESS-cell differentiation. We found no difference concerning regulator factors for B cell differentiation between bone marrow cell culture supernatants from multiple myeloma (MM) patients and from controls, whereas significantly higher suppressor activity on polyclonal B cell proliferation could be detected in the former group of supernatants. The extent of such determined suppressor activity in vitro correlated with the amount of polyclonal serum IgM of the corresponding patients. These results indicate that one or several soluble suppressor factors may be involved in immunoregulatory mechanisms responsible for the humoral immunodeficiency observed in MM patients.

B-Lymphocytes↗