Biomedical subjects

J Dauth

Publications and source records attributed to J Dauth.

At least 19 recordsLinked to original sources

PubMed1998

Geographic variations in the composition of ivory of the African elephant (Loxodonta africana).

Tracing the source of origin of illegal ivory will contribute to the identification of poorly managed game parks and facilitate steps taken to prevent the African elephant from becoming extinct. This study was aimed at establishing a database on the composition of ivory obtained from elephant sanctuary areas in Southern Africa. Fragments of elephant ivory from seven geographically distinct areas in South Africa, Namibia and Botswana were analysed for inorganic and organic content. A total of 20 elements was detected in the inorganic fraction of ivory, some in concentrations as low as 0.25 microg/g. The concentrations of calcium, phosphate, magnesium, fluoride, cobalt and zinc showed statistically significant differences (p < 0.007) between ivory obtained from different regions. Analyses of the organic fraction identified 17 amino acids. Ivory from arid regions showed significantly lower proline plus hydroxyproline content and under-hydroxylation of lysine residues. This study indicates that chemical analyses of ivory could be beneficial in tracing the source of illegal ivory.

Africa, Southern↗

PubMed1993

Salivary immunoglobulin related proteins in 24 patients with multiple myeloma.

Mixed saliva and blood of 24 cases of multiple myeloma (MM) were collected and the immunoglobulin and light chain concentrations compared with that found in the saliva and blood of 16 age matched control patients. The concentrations of salivary IgA, IgG and lambda light chains were significantly increased in IgA-, IgG- and lambda light chain producing MM respectively. Salivary IgA concentration in non-IgA MM and salivary IgG concentration in non-IgG MM were within normal ranges. Despite a significant decrease in circulating normal immunoglobulins, this study fails to support suppression of normal salivary immunoglobulin concentrations in patients suffering MM.

Humans↗

PubMed1993

The cupruretic effect of two chelators following copper loading in sheep.

The cupruretic effect of 2 copper chelators, d-penicillamine and trientine, was assessed in 12 fistulated South African Mutton Merino rams of approximately 6 mo age following copper loading. Each animal received 20 mg CuSO4.5H(2)0/kg body mass as an 0.5% m/v aqueous solution, intraruminally, daily for 35 d. The animals were randomly assigned to either a d-penicillamine (n = 4) or trientine treatment group (n = 4) or an unmedicated control group (n = 4). A separate group of 3 rams were kept as non-copper-loaded controls. Urinary copper excretion was measured before and during treatment. All the sheep were housed individually or placed intermittently on steel metabolic crates to facilitate urine collection. At the end of the trial the animals were euthanatized and specimens of organs collected for determination of copper concentrations. d-Penicillamine significantly (p < 0.05) increased urinary copper excretion. Trientine failed to increase copper excretion in the urine when compared to the unmedicated and non-copper-loaded control groups.

Animals↗

PubMed1993

Selected biochemical parameters in captive mountain tortoises (Geochelone pardalis).

The concentrations of sodium, potassium, chloride, urea, creatinine, uric acid, total protein, albumin, inorganic phosphorous, calcium, magnesium, cholesterol, triglyceride, glucose, aspartate and alanine transaminases (AST and ALT), creatine kinase (CK), lactic acid dehydrogenase (LD), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP) and total bilirubin in the serum of a captive population of the mountain tortoise (Geochelone pardalis) (n = 13) were determined. Results varied considerably, particularly for most enzymes such as AST (11-113 U/l,ALT (1-72 U/l), CK (12-242 U/l), LD (147-2641 U/l) and ALP (56-168 U/l).

Animals↗

PubMed1992

Amino acid composition of dentine in permanent human teeth.

Dentine of permanent mandibular incisors from nine individuals was hydrolysed and the amino acid composition determined by ion-exchange chromatography against a standard calibrant of 41 amino acids. Nineteen amino acids were detected, including small quantities of 1-methylhistidine and asparagine, two amino acids whose existence had apparently not been recorded before in human dentine. The total content of hydroxylysine plus lysine varied between 2.6 and 3.3 residues per 100 (SD, 0.74) in different teeth, which therefore did not support previous studies that had proposed a constant total value. This and other quantifiable differences between present and previous findings may be the result of the different methods and the influence of dietary and other regional factors on dentinogenesis.

Amino Acids↗

PubMed1992

Immunization of guinea-pigs and cattle against adult Rhipicephalus appendiculatus ticks using semipurified nymphal homogenates and adult gut homogenate.

Guinea-pigs inoculated with crude homogenate of unfed nymphs of the tick Rhipicephalus appendiculatus and with three semipurified fractions of the homogenate obtained by gel permeation chromatography, acquired a significant degree of immunity to infestation with adults of this tick. Fraction 2 induced the highest reduction (66%) in mean weight of engorged females followed by crude homogenate and fractions 1 and 3. Calves immunized with crude homogenates of unfed nymphs, fraction 2 of nymphal homogenate, and gut homogenate of unfed females also acquired immunity against adults of R. appendiculatus. The mean weight of engorged females fed on calves inoculated with nymphal fraction 2 was the lowest of all five groups of calves on which females fed. The reduction in weight (38%) was not significantly different from that observed for females fed on calves inoculated with crude nymphal homogenate (31%) or females from third infestation of adult ticks. No differences in the weight and hatchability of egg batches produced by engorged females collected from the five groups of calves were observed. Analysis of sera collected from the five groups of calves showed that the concentration of albumin, alpha-1, alpha-2 and beta-globulins fluctuated and no significant differences between the treated groups were observed. The levels of gamma-globulin increased in treated groups including the group inoculated with adjuvant only, but unlike previous reports no increase in gamma-globulin or a correlation between the level of gamma-globulin and the degree of resistance acquired were observed in calves exposed to repeated tick infestations. However, the increase in the concentration of gamma-globulin in calves inoculated with fraction 2 or crude nymphal homogenate was higher than that observed in the other groups.

Animals↗

PubMed1991

Serum beta-2-microglobulin in the differential diagnosis of monoclonal gammopathies.

Serum beta-2-microglobulin (B2m) concentrations were determined in 43 southern African black patients with multiple myeloma (MM), in 130 black patients with monoclonal gammopathy of undetermined significance (MGUS) and in 70 control subjects. The results showed median values for serum B2m in patients with MM, MGUS and the control group to be 8.10 mg/l, 3.05 mg/l, and 2.35 mg/l, respectively; these values differed significantly from one another (P less than 0.01), even when patients with normal renal function (serum creatinine value less than 110 mumol/l) were considered separately. The median serum B2m concentration for IgG MM (22 cases) was 4.3 mg/l, for IgA MM (8 cases) 7.3 mg/l, and 24.2 mg/l for Bence Jones MM (12 cases). These differences were also significant (P = 0.001), but not in the restricted group of MM patients with normal renal function. In the 43 MM patients serum B2m concentrations had a significant positive correlation with serum creatinine (r = 0.706; P less than 0.005) and a significant negative correlation with haemoglobin values (r = -0.459; P = 0.006). In 28 MM patients with normal renal function, serum B2m values had a significant negative correlation with serum albumin (r = -0.602, P = 0.003). Sixty-five per cent of the 43 MM patients and 18.5% of the MGUS patients had raised serum B2m values (greater than 4.7 mg/l). An optimum cut-off value for serum B2m of 6.9 mg/l for differentiating MM from MGUS was determined using a classification rule. Despite lacking specificity, serum B2m measurement was useful in differentiating MM from MGUS, and was the best second choice variable in relation to serum albumin and haemoglobin in patients with normal renal function.

Creatinine↗

PubMed1991

Acquisition of immunity in cattle against the blue tick, Boophilus decoloratus.

It is well known that ixodid ticks have the ability to induce immunity in their host. We demonstrate, for the first time, that the tick Boophilus decoloratus induced immunity in its bovine host, since the mean weight of engorged females fed on naive animals dropped from 201.5 mg, to 173.7 mg and 155.3 mg, for females fed on calves previously exposed once and twice; respectively, to B. decoloratus infestations. Ticks which had been transferred from one individual host to another one were able to complete their feeding period on a sensitive host. Such ticks were significantly heavier (mean 245.2 mg) than those fed on a naive (mean 201.5 mg) host for the entire normal feeding period. A negative correlation between the mean weight of the engorged female ticks and the level of serum gamma globulins in the host was also demonstrated.

Animals↗

PubMed1991

Non-secretory IgA kappa myeloma with distended endoplasmic reticulum: a case report.

A case of non-secretory multiple myeloma is presented. Plasma cells showed abundant cytoplasmic colloid contained in distended rough endoplasmic reticulum. Uniform cytoplasmic positivity for IgA heavy- and kappa light-chains was demonstrated with the immunoperoxidase staining technique. It is proposed that distension of the endoplasmic reticulum by immunoglobulin-related proteins is indicative of a block in their excretion or of the presence of active synthesis of the immunoglobulins or their subunits.

Endoplasmic Reticulum↗

PubMed1991

Development of resistance in laboratory animals to adults of the tick Rhipicephalus evertsi evertsi.

Acquired resistance to adults of the two-host tick Rhipicephalus evertsi evertsi Neumann has been demonstrated in guinea-pigs and rabbits. Four infestations of both hosts with R.e.evertsi adults resulted in a significant reduction in the mean weight of the engorged females. A decline in the mean weight of the female ticks was also observed in ticks which fed on a rabbit previously injected with serum taken from a rabbit resistant to R.e.evertsi. This suggests that humoral immunity may have an important role in the acquired resistance to ticks. In both hosts an increase in the level of serum globulins was recorded. In rabbits the level of gamma globulin was affected, while in guinea-pigs an increase was observed in the concentration of alpha 1 and beta globulins. The differences in host responses to the R.e.evertsi adults are discussed.

Animals↗

PubMed1991

Immobilization of wild dogs (Lycaon pictus) with a tiletamine hydrochloride/zolazepam hydrochloride combination and subsequent evaluation of selected blood chemistry parameters.

A tiletamine hydrochloride/zolazepam hydrochloride combination was used successfully to immobilize captive untamed wild dogs (Lycaon pictus) (n = 16) at dosage rates ranging from 2.3 to 32.3 mg/kg. Animals remained immobilized for periods ranging from 35 min to 24 hr 14 min. There was a significant positive correlation (r = 0.85, P less than 0.01) between dosage rate and the time immobilized. Profuse salivation and intermittent mild myoclonal contractions were observed in some wild dogs. Mildly reduced partial oxygen and carbon dioxide pressures as well as reduced concentrations of bicarbonate were observed in arterial blood at 10 and 20 min after administration of the drug. Serum concentrations of sodium, potassium, chloride, phosphorus, calcium, magnesium, urea, creatinine, glucose, proteins, albumin, gammaglutamyltransferase, creatinine kinase, aspartate transaminase, alkaline phosphatase, lactate dehydrogenase, insulin, cortisol and thyroxine are presented. These concentrations were found to be in agreement with values previously reported for wild dogs.

Animals↗

PubMed1990

Resistance of Brahman and Simmentaler cattle to southern African ticks.

Field collections of ticks from two breeds of cattle in the North Western Transvaal showed the common tick species to be Rhipicephalus appendiculatus, Amblyomma hebraeum, Rhipicephalus evertsi evertsi and Hyalomma marginatum rufipes. The number of these ticks was higher on Simmentaler than on Brahman cattle. Correlation was found between the number of ticks on the cattle and their serum gamma globulin levels indicating an increase in the production of antibodies. Similar correlation was also found between the number of ticks on the cattle and the number of eosinophils in their blood. Resistance was probably acquired by the hosts and, it appears, to a higher degree in Brahman than in Simmentaler.

Animals↗

PubMed1990

Selected laboratory parameters of thoroughbreds.

Selected haematological, blood chemical and serological variables were investigated in healthy Thoroughbreds (n = 45) in training. Haemoglobin concentration, haematocrit, red, white and differential cell counts as well as serum concentrations of total and ionized calcium, sodium, potassium, chloride, urea, creatinine, total protein, albumin, inorganic phosphorus, total bilirubin, iron, glucose, magnesium, alkaline phosphatase, gamma-glutamyltransferase, lactate dehydrogenase, aspartate transaminase, alanine transaminase and creatine kinase were found to be within ranges previously reported for horses. No statistically significant difference was found between the haematocrit (Ht) of horses n = 44; mean = 0.44; SD = 0.02) of different performance or between those of different age groups. A significant difference was found between the Ht of males (mean = 0.43; SD = 0.02) and females (mean = 0.45; SD = 0.02) and between quiet (mean = 0.44; SD = 0.02) and excitable (mean = 0.46; SD = 0.02) horses. No significant difference in red cell potassium concentration was found between horses of different performance. Cortisol, insulin, parathormone (C-terminal), aldosterone and folate concentrations respectively varied between 89-204 (mean = 144.4; SD = 25.47) nmol l-1, 4.2-23 (mean = 10; SD = 4.30) m U l-1, 65.2-91.4 (mean = 79.46; SD = 9.34) pmol l-1, less than 138 to 379 pmol l-1 and 9.4-21.5 (mean 14.5; SD = 2.87) nmol l-1. Vit B12 concentrations exceeded 1400 pmol l-1. Blood lead concentrations in all animals were below 15 ug l-1. Fifteen (33.3%) of the horses were carriers of babesiosis. Laboratory findings concerning these horses did not differ from those of the other horses.

Animals↗

PubMed1989

Comparison of the sodium contents of six commonly recommended oral rehydration solutions.

The sodium contents of six differently prepared oral rehydration solutions (ORS) were measured. A total of 452 solutions were prepared in our gastro-enteritis unit. The finger-pinch-and-cup method produced sodium values that were too high and too variable. The most acceptable sodium level was achieved using half a 5 ml medicine teaspoon or 1 level common household teaspoon of salt in 1 litre of water. Half a commonly available household teaspoon of salt caused sodium levels to be low but still acceptable and safe. We recommend that half a teaspoon of salt in 1 litre of water be used when preparing an ORS.

Fluid Therapy↗

PubMed1989

Imaging benzodiazepine receptors in the human brain by single photon emission computed tomography (SPECT).

Recently, [123I]Ro16-0154 has been introduced as a potential benzodiazepine (BZD) receptor imaging tracer for SPECT. We investigated the biodistribution of [123I]Ro16-0154 in humans and compared it with the animal data. There was a rapid and high 123I-uptake in the brain comparable to rCBF. In the following images, however, regionally different changes were observed, resulting in a subsequent intracerebral retention parallel to the known distribution of BZD receptors. The results suggest that [123I]Ro16-0154 is of potential clinical use as a BZD receptor imaging agent.

Adult↗

PubMed1989

Changes in the concentration of globulins in naive guinea pigs during feeding by the immature stages of Rhipicephalus evertsi evertsi (Acari: Ixodidae).

The weight of Rhipicephalus evertsi evertsi Neumann nymphs, which as larvae and nymphs completed the entire blood meal on the same individual guinea pig, was significantly lower than the weight of those that as larvae and nymphs fed on two separate naive hosts. Nymphs of the latter category spent 1 wk (from unfed larvae to unfed nymphs) on one animal before their transfer to the second host to complete the blood meal. The albumin concentration of the host blood decreased and was related to the time that the immature ticks spent on the hosts. The albumin/globulin ratio also decreased. The alpha 1 globulin fraction increased soon after the guinea pigs were infested with ticks. No further changes in the levels of the alpha 1 globulin fraction were observed with time. The concentration of serum beta globulins increased only in guinea pigs infested with immature ticks for the entire larval and nymphal feeding period. A second infestation of those guinea pigs with larvae of R. e. evertsi resulted in further increases in the levels of serum beta globulins. The relationships among serum beta globulin levels, the weight of engorged nymphs, and host immunity are discussed.

Animals↗

PubMed1988

Multiple myeloma presenting as localized expansile jaw tumour.

Myelomatous involvement of the maxilla is an exceptionally rare occurrence, and the presentation of the lesion as an expansile jaw bone tumour has not been reported. 2 cases, one with a maxillary lesion, the other with a mandibular lesion are presented, both of which illustrate gross bone expansions. Additionally, 1 case presented with a rare biclonal IgG kappa and IgG lambda light chain secreting myeloma. Relevant clinical, immunological, histological, biochemical and histochemical features are presented and discussed, and suggestions pertaining to surgical management made.

Adult↗

PubMed1988

Multiple myeloma and amyloidosis of the tongue.

Tongue biopsies of 30 diagnosed cases of multiple myeloma were examined light and electron microscopically and amyloid deposits were identified in 8 patients. Immunochemical typing of amyloid in kappa and lambda subtypes was performed successfully although positive staining of tissue-associated immunoglobulin light chains made reliable identification of amyloid with this technique difficult. Cells of macrophage lineage appear to play a central role in light chain-associated amyloidogenesis. Our findings do not agree with the reported higher amyloidogenic potential of lambda light chains and we were unable to show a positive correlation between the percentage plasma cells in bone marrow aspirates or the presence of urinary light chains and myeloma-associated amyloidosis.

Adult↗