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Biomedical subjects

P Mayer

Publications and source records attributed to P Mayer.

At least 145 records · Page 8Linked to original sources
PubMed1990

Decrease of macrovascular hyperemic response of blood flow in diabetics with arterial neuropathy.

Doppler sonographic examination of 51 diabetic subjects showed that the macrovascular hyperemic response of the pedal blood flow was negatively correlated to the duration of the disease (p less than 0.01). In comparison with non-diabetic controls (n = 20), the response was increased by more than 210% in newly detected diabetics, but decreased by more than 20% in long-term diabetics. Vascular response was correlated also not only to the duration of the diabetes, but to peripheral neuropathy (p less than 0.001). The hyperemic response was reduced in patients with reduced nerve conduction time, or somatic neuropathy (142 + 152%, p less than 0.005), and in patients with reduced arterial pulsation, or autonomic neuropathy (152 + 88, p less than 0.005), both in comparison with non-diabetic controls (293 +/- 108%). The frequency of decreased macrovascular hyperemic response was in agreement with somatic neuropathy in 69.7% and with autonomic neuropathy in 75.8% of all patients. The results demonstrate that the macrovascular hyperemic response of blood flow in diabetic feet is already reduced at an early stage of peripheral neuropathy without peripheral vascular occlusive disease. The functional reduction of pedal blood flow may be important for the development of diabetic foot gangrene.

Adult↗
PubMed1990

Recombinant human interleukin-3 expands the pool of circulating hematopoietic progenitor cells in primates--synergism with recombinant human granulocyte/macrophage colony-stimulating factor.

The in vivo effect of recombinant human interleukin-3 (rhIL-3) on peripheral blood (PB) levels of hematopoietic progenitor cells was studied in nonhuman primates. Subcutaneous administration of 33 micrograms/kg/d of rhIL-3 for 11 to 14 days to rhesus monkeys slightly raised leukocyte counts (twofold) and substantially expanded the pool of circulating stem cells in the second week of treatment. At the end of rhIL-3 administration, PB levels of granulocyte/macrophage colony-forming units (CFU-GM) increased by a mean of 12-fold; burst-forming units-erythroid (BFU-E) by ninefold; CFU-mix, by 12-fold; and CFU-megakaryocyte (Mk), by 13-fold as compared with their respective pretreatment values. Subsequent administration of recombinant human granulocyte/macrophage colony-stimulating factor (rhGM-CSF; 5.5 micrograms/kg/d for 5 days) to rhIL-3-pretreated animals further expanded the PB stem cell compartment leading to maximum levels of CFU-GM that were in average much more increased (63-fold) than CFU-GM levels under rhIL-3 (14-fold) or rhGM-CSF (12-fold) alone. This hitherto unknown effect of rhIL-3 on the pool of circulating progenitors, particularly in synergy with rhGM-CSF, may facilitate harvest of hematopoietic progenitor cells from PB for stem cell transplantation.

Animals↗
PubMed1990

Bronchoalveolar lavage in dogs; analysis of proteins and respiratory cells.

In an attempt to establish the normal values, bronchial alveolar lavage (BAL) of portions of the right upper lobe was done during fiberoptic bronchoscopy in 18 Beagle dogs of various ages. Albumin, IgA and IgG were identified in BAL fluids. The respiratory cells obtained were, in the order of decreasing occurrences, alveolar macrophages, lymphocytes, epithelial cells and neutrophils. No age-related changes were found in the content of immunoglobulins or in the differential cell counts of respiratory cells. Bacterial cultures of BAL were invariably contaminated with resident flora of the upper respiratory tract. Therefore, in determining the etiology of pulmonary infections, the results of such cultures should be interpreted with caution. As an aid to diagnosis of pulmonary diseases in dogs, the analysis of BAL fluid components could be helpful when compared with findings in healthy animals.

Albumins↗
PubMed1990

Total communication use among elementary teachers of hearing-impaired children.

This study examined the degree to which teachers' signed Manually Coded English messages represented their spoken utterances. Results indicate that educators in early elementary programs can, and do, provide a complete manual representation of their spoken English messages. This is in contrast with earlier research with middle school educators and parents of hearing-impaired children. Findings indicate that MCE proficiency may be influenced both by teacher attitude regarding the importance of signing a complete message and the degree to which program supervisors monitor teacher implementation of clearly specified MCE policies. Findings from this study have implications for programs to train teachers in using MCE and also provide information on the effects of program policy on teacher use of sign language.

Child↗
PubMed1990

The Tulving-Wiseman law and the recognition of recallable music.

Memory for well-known musical phrases was tested first for recognition in the absence of any specific musical context and then for recall given the preceding musical phrase as a contextual cue. Recognition and recall were found to be largely, but not completely, independent. Moreover, there was no evidence of any greater dependency between recognition and recall than that previously observed in the relation between word recognition and recall, as summarized by the Tulving-Wiseman law. These findings significantly extend the range of applicability of this law.

Adult↗
PubMed1990

In vitro and in vivo activity of human recombinant granulocyte-macrophage colony-stimulating factor in dogs.

Although it is well documented that human granulocyte-macrophage colony-stimulating factor (GM-CSF) controls the production and functional activity of human and nonhuman primate granulocytes and macrophages, relatively little is known about its effects on cells obtained from other species. The molecular cloning of the complementary DNA for human GM-CSF has made it possible to determine the cross-reactivity of the purified recombinant human material (rhGM-CSF) on cells of other species. The results presented herein show that specific receptors for human GM-CSF exist on dog bone marrow cells and mature circulating dog granulocytes. The number of the receptors and the apparent binding affinity of the rhGM-CSF to its receptors on granulocytes were similar to those observed either on human or monkey cells. In cultures of dog bone marrow cells, rhGM-CSF was capable of promoting colony formation in a dose-dependent manner. Human GM-CSF also primed dog granulocytes for increased production of reactive oxygen metabolites in response to either phorbolmyristic acetate-or zymosan-activated dog serum. In vivo, s.c. administration to healthy dogs of rhGM-CSF in daily doses of 15, 50, or 150 micrograms/kg body weight over a period of 7-20 days induced a dose-dependent rise of up to a maximum of a fourfold increase in peripheral WBC counts. The rise in WBC counts was mainly due to elevated neutrophil levels, but an increase in the numbers of monocytes and eosinophils was also observed. However, the rhGM-CSF-induced leukocytosis in dogs was not as dramatic as that observed in nonhuman primates. In all rhGM-CSF-treated dogs, circulating platelet counts dropped to nadir levels of about 20%-30% of normal numbers. Dogs that were treated with 150 micrograms/kg rhGM-CSF developed specific antibodies after about 10-12 days of treatment. These antibodies were able to neutralize the effect of rhGM-CSF in in vitro assays. In vivo WBC counts began to decline when specific antibodies developed, but they never dropped below normal levels. Taken together, the results suggest that human GM-CSF does not appear to exhibit absolute species specificity.

Animals↗
PubMed1989

The in vivo effects of recombinant human interleukin-3: demonstration of basophil differentiation factor, histamine-producing activity, and priming of GM-CSF-responsive progenitors in nonhuman primates.

Recently human interleukin-3 (IL-3) produced by molecular cloning was characterized as a growth factor for basophils and eosinophils in human bone marrow cultures. Since we found a similar activity of the human factor on simian bone marrow cells, we investigated the in vivo effects of recombinant human (rh) IL-3 in healthy rhesus monkeys (n = 10). rh IL-3 was administered subcutaneously (SC) to monkeys at different doses (11, 33, and 100 micrograms/kg/d) for 14 days followed by subsequent rh GM-CSF administration (5.5 micrograms/kg/d SC) for another two weeks. During the second week of rh IL-3 administration monkeys responded with a twofold to threefold increase of WBCs caused by a dose-dependent elevation of basophils (up to 40% of WBCs) and eosinophils. rh IL-3 also induced a dose-dependent increase of histamine (up to 700-fold above normal values) in monkey blood cells. Administration of rh GM-CSF to rh IL-3 pretreated monkeys resulted in a twofold enhanced increase in WBCs (due mainly to eosinophils and neutrophils) compared with animals treated with rh GM-CSF alone. Simultaneous administration of both cytokines (100 micrograms/kg rh IL-3 + 5.5 micrograms/kg rh GM-CSF SC) to two separate monkeys for 14 days induced a WBC elevation similar to that observed in monkeys treated with rh GM-CSF alone. In conclusion, our results indicate that rh IL-3 is a differentiation factor for blood basophils and primes the hematopoietic system for subsequent rh GM-CSF actions.

Animals↗
PubMed1989

Interleukin-3 is a differentiation factor for human basophils.

The effect of recombinant human (rh) cytokines, interleukin-1 alpha (IL-1 alpha), interleukin-2 (IL-2), interleukin-3 (IL-3), interleukin-4 (IL-4), granulocyte/macrophage colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), monocyte/macrophage colony stimulating factor (M-CSF), interferon-alpha (IF-alpha), interferon-gamma (IF-gamma), and the tumor necrosis factor-alpha (TNF-alpha) on differentiation and function of metachromatic cells (MCS) was studied. Among all cytokines tested, rh interleukin-3 (rhIL-3) selectively induced a significant formation of MCS (IL-3: 1.1 +/- 0.6 x 10(5) v control: 0.02 +/- 0.15 x 10(5) MCS/mL suspension) and dose dependent increase in formation of intracellular histamine (IL-3, 100 U/mL: 95 +/- 23 ng/mL v control: 1.8 +/- 0.8 ng/mL) in a bone marrow suspension culture system (analyzed on day 14 of culture). Besides MCS, formation of eosinophils was observed in this culture system in the continuous presence of rhIL-3, whereas IL-3 pulse-stimulation for three hours and subsequent exposure to control medium induced growth of MCS but not of eosinophils. By combined immunofluorescence/toluidine blue staining, MCS were found to express a cell surface marker profile that corresponds to the immunological phenotype of peripheral blood basophils (MY-7(CD13)+, VIM12(CD11b)+, VIM2+, MAX1-, MAX24- and YB5B8-). Furthermore, cultured MCS expressed surface membrane receptors for IgE and could be triggered for nontoxic histamine release by a monoclonal anti-IgE antibody. To evaluate a possible influence of IL-3 on basophil function, studies were extended to freshly obtained blood basophils (healthy volunteers, n = 3). However, like all other cytokines tested, rhIL-3 failed to induce basophil histamine release. Taken together, our studies demonstrate that IL-3 is a differentiation factor for human basophils.

Antibodies, Monoclonal↗
PubMed1989

[Vascular changes in essential hypertension after treatment with enalapril].

A group of patients with essential hypertension and healthy subjects from the same work place were investigated for a period of four weeks and were subjected, in addition to a basic clinical medical examination, to an ergometric examination ECHO cardiography, occlusion plethysmography, and concurrently serum levels of adrenaline (A), noradrenaline (NA), renin, cyclic adenosine monophosphate (cAMP) beta receptors before and after four weeks treatment with enalapril were assessed. The results are consistent with available data from the literature where administration of inhibitors of the angiotensin converting enzyme (ACE) caused a reduction of the peripheral vascular resistance and increased blood flow assessed by means of occlusion plethysmography. Similar results were recorded after captopril administration for a one year period, as reported by Agabiti-Rose (1). Statistically significant differences were detected between hypertonics given placebo and those given enalapril for four weeks, as regards blood flow at rest and peripheral vascular resistance at rest. There was also a significant difference when hypertonic and normotonic subjects were compared. The results are presented in tables and figures.

Adult↗
PubMed1988

The natural course of peripheral and autonomic neural function during the first two years after diagnosis of type 1 diabetes.

Motor and sensory nerve conduction velocities (MNCV, SNCV), beat-to-beat variation (BBV) at rest, speed of pupillary dilation (SPD), and pupillary latency time (PLT) were measured in 32 patients aged 12-36 years after 19 +/- 2 (mean +/- SEM) days and again after 3, 12, and 24 months of insulin treatment. Moreover, BBV under deep respiration was determined after 12 and 24 months, and thermal discrimination thresholds (TDT) as well as pain and vibration perception thresholds (PPT; VPT) were evaluated after 24 months. Mean HbA1 levels during months 3-24 within the normal range (7.2 +/- 0.2%; mean +/- SEM) were observed in 20 patients (group 1), while in 12 patients (group 2) mean HbA1 of months 3-24 was elevated (10.1 +/- 0.4%). There were no significant differences between both groups with regard to the nerve function tests at baseline and after 3 months. After 12 months mean median MNCV and median, ulnar, and sural SNCV were significantly lower in group 2 than in group 1 (p less than 0.05). After 24 months mean median MNCV, peroneal MNCV, median SNCV, and sural SNCV as well as both BBV tests and PLT were significantly impaired in group 2 as compared to group 1 (p less than 0.05). In addition, mean malleolar VPT and PPT to heat and cold stimuli on the thenar and the foot were significantly elevated in group 2 as compared to group 1 (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Epidemiology and vectors of Dracunculus medinensis in northwest Burkina Faso, West Africa.

The epidemiology of the guinea worm, Dracunculus medinensis, was studied in the dry savanna zone of West Africa. The monthly incidence data collected over a period of four years showed peak transmission occurring in June and July at the beginning of the rainy season. The different types of local water sources (i.e. wells, periodic streams, seasonal cattle waterings, natural ponds and man-made ponds) were examined for infected cyclopoid copepods. Small hand-dug ponds or water-holes situated in the fields proved to be the most important sites of transmission. While the domestic water supply is obtained from draw-wells in the villages throughout the year, the villagers take additional drinking water from these ponds during the planting season when farm activities require long stays in the fields. Four cyclopoid species were found for the first time acting as natural intermediate hosts of D. medinensis. Thermocyclops inopinus was the most frequently infected cyclopoid, and small man-made ponds are the preferred habitats of this species. Occurrence of T. inopinus is confined to the first half of the rainy season, coinciding with peak transmission. The epidemiology of dracunculiasis in dry and humid regions of West Africa is compared with regard to seasonality. The use of protective water filters proved to be the only adequate method for guinea worm control in the project area.

Animals↗
PubMed1988

Evaluation of thermal, pain, and vibration sensation thresholds in newly diagnosed type 1 diabetic patients.

Small and large fibre function was studied in 40 non-ketotic, newly diagnosed Type 1 diabetic patients and 48 age-matched controls, using 12 quantitative tests for assessment of cutaneous sensation. Patients were aged 10-39 years and had been treated with insulin for 4-31 days. Thermal discrimination (foot), warm and cold thermal perception (thenar eminence and foot), and heat and cold pain perception thresholds (thenar eminence) were significantly elevated in the patients as compared with the controls (p less than 0.05 to p less than 0.001). No significant differences in thermal discrimination (thenar), heat and cold pain perception (foot), and metacarpal as well as malleolar vibration perception thresholds were noted between the groups. The rates of abnormalities among the individual tests ranged from 0% to 27.5%, being lowest for vibration perception and highest for thermal perception thresholds after cold stimuli. The results in nine of 12 tests correlated significantly with age, but only two were related to HbA1c. Thus, sensory neural functions transmitted by small fibres, but not those transmitted by large fibres, were impaired in newly diagnosed Type 1 diabetics after the correction of initial ketosis and hyperglycaemia. Cooling perception tests were most sensitive in detecting abnormality. An age-related involvement of different small fibre functions was present in these patients.

Adolescent↗
PubMed1988

Congenital anaplastic astrocytoma with favorable prognosis. Case report.

A large intracranial tumor that caused macrocrania leading to dystocia was demonstrated by prenatal ultrasound examination. After birth, computerized tomography (CT) confirmed the presence of a giant supratentorial tumor with a large cyst. When the infant was 20 days old, the tumor was radically extirpated. Neuropathological examination revealed an astrocytoma with focal signs of anaplasia showing a macrocyst as well as multiple microcysts resulting from hemorrhages into the tumor. Although no adjuvant radio- or chemotherapy was administered, the child had nearly normal psychomotor development without clinical or CT evidence of tumor recurrence, and is now 3 years old.

Astrocytoma↗
PubMed1988

Somatic and autonomic nerve function during the first year after diagnosis of type 1 (insulin-dependent) diabetes.

Somatic and autonomic nerve function was assessed by motor and sensory nerve conduction velocities (MNCV; SNCV), beat-to-beat variation at rest, speed of pupillary dilation, and pupillary latency time in 35 newly diagnosed type 1 diabetic patients aged 12-36 years. The nerve function tests were performed 18 +/- 2 (mean +/- SEM) days after the correction of initial ketosis and hyperglycaemia and again after 3 and 12 months of insulin therapy. Mean HbA1 levels of months 3 and 12 within the normal range less than 8.6% (mean: 7.2 +/- 0.2%) were observed in 24 patients (group 1) and greater than or equal to 8.6% (mean: 10.1 +/- 0.6%) in 11 patients (group 2). Group 1 showed no significant changes from baseline in the mean nerve conduction and autonomic functions after 3 and 12 months. In group 2 there was no change until three months, however, at 12 months there was a significant decrease in mean MNCV in the median, ulnar and peroneal nerves (p less than 0.05) and in mean SNCV in the median (p less than 0.05) and sural nerves (p less than 0.01), when compared to the baseline values. The autonomic function tests remained unchanged. No patient had symptoms of neuropathy during the period studied. These findings suggest that the deterioration of motor and sensory nerve conduction precedes that of cardiac and pupillary autonomic function in poorly controlled asymptomatic type 1 diabetic patients during the first year of the disease. Effective glycaemic control prevented progression of subclinical neuropathy, but did not reverse abnormalities which were present at diagnosis.

Adolescent↗
PubMed1987

Biological assessment of exposure to antimony and lead in the glass-producing industry.

The oxide of trivalent antimony is used in the glass-producing industry as a refining agent and as a glass colouring. The batch contains up to 2% Sb2O3, a substance which has shown carcinogenic properties in animal experiments. The internal levels of antimony and lead in blood (SbB and PbB) as well as the excretion with the urine (SbU and PbU) were determined by hydrid and electrothermal atomic absorption (HY-AAS and ET-AAS), respectively. In addition, measurements of airborne Sb2O3-concentrations were performed. The 109 volunteers were employed in four different fields: melting area, batch bunker, glass-washing area, and transport/maintenance. Differences between the concentrations of antimony and lead in blood and urine with respect to the fields of activity were evaluated statistically. The highest values of airborne Sb2O3, with up to 840 micrograms/m3 (TWA), were detected in the batch bunker. Correspondingly, significantly enhanced SbU-values from 1.5 to 15.7 micrograms/l (median: 5.0 micrograms/l) were found in specimens collected from the batch mixers. In the same group, the lead excretion (PbU) with values from 9 to 110 micrograms/l (median: 43 micrograms/l) was also found to be the highest. Due to the fast renal excretion of antimony, the determination of SbU is useful for biological monitoring.

Adult↗
PubMed1987

Efficacy of recombinant human granulocyte-macrophage colony-stimulating factor in rhesus monkeys.

The glycosylated and the non-glycosylated recombinant human granulocyte-macrophage colony-stimulating factor (rh GM-CSF) expressed in Chinese hamster ovary cells and E. coli, respectively, were administered in rhesus monkeys either by the subcutaneous (three times daily) or intravenous route (6-hr infusions) for seven consecutive days. Within 24 hr peripheral white blood cells (WBC) increased 2-3 fold over normal values. Thereafter, the WBC increased steadily in a dose-dependent manner to reach maximum levels on the last day of or one day after the treatment period. The differential counts showed that neutrophils contributed to 50-80%, eosinophils to 10-20%, monocytes to 2-7%, and lymphocytes to 15-30% of the WBC rise. No effect was found on platelets and erythrocytes. After termination of treatment, WBC counts returned to normal levels within one week. Subcutaneously administered CSF was more effective in inducing leukocytosis than that injected intravenously In addition to the rise in WBC, the administered rh GM-CSF also enhanced the oxidative metabolism and bactericidal activity of the circulating mature granulocytes isolated from the blood of monkeys treated with rh GM-CSF. These results show that glycosylated or non-glycosylated rh GM-CSF is both an effective stimulator of leukocytosis and a potent activator of the functional activity of mature granulocytes in vivo.

Animals↗