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Biomedical subjects

J Richmond

Publications and source records attributed to J Richmond.

At least 37 records · Page 2Linked to original sources
PubMed1994

Parkinsonism induced by solvent abuse.

We report the first description of a patient with parkinsonism induced by solvent abuse. Our patient developed parkinsonism acutely, following heavy abuse of lacquer thinner. Her clinical deficits were indistinguishable from idiopathic parkinsonism (Parkinson's disease) and she responded to levodopa. Parkinsonism has persisted for more than 3 months. Brain computed tomography was normal. Positron emission tomographic studies showed normal fluorodopa uptake and reduced raclopride binding, indicating an unusual disturbance of striatal dopaminergic function. This patient suggests that organic solvents may cause parkinsonism in susceptible individuals.

Administration, Inhalation↗
PubMed1994

The demonstration of an essential role for macrophages in the in vivo generation of IgG2a antibodies.

BALB/c mice were depleted of macrophages by intravenous inoculation of dichloromethylene diphosphonate entrapped in liposomes 24 h before primary and 24 h before secondary sensitization intravenously with 100 micrograms bovine serum albumin (BSA) or ovalbumin (OVA). The effectiveness of macrophage depletion was confirmed by immunocytochemistry. Five days and 14 days after secondary challenge with BSA, plasma samples from these and control mice inoculated with empty liposomes were examined for the production of BSA-specific IgG1 and IgG2a antibodies. Macrophage depletion resulted in a significantly increased production of the Th2 lymphocyte-associated IgG1 isotype, while the production of specific IgG2a antibodies, produced under the influence of Th1 cells, was totally ablated. Similar results were obtained when OVA was used as the test antigen. Furthermore, analysis of interferon-gamma (IFN-gamma) production after antigen or concanavalin A (Con A) restimulation in vitro indicated that macrophage depletion in vivo significantly reduced production of this Th1 cell-associated cytokine. These results provide strong in vivo and in vitro evidence for the macrophage being the antigen-presenting cell population responsible for Th1 cell activation.

Animals↗
PubMed1994

p53 immunoreactivity in cervical intraepithelial neoplasia and non-neoplastic cervical squamous epithelium.

AIMS: To determine the pattern of p53 immunoreactivity in cervical squamous epithelium and to investigate the relation between p53 immunostaining and human papillomavirus (HPV) infection. METHODS: Immunocytochemistry for p53 was performed in 65 specimens of formalin fixed, paraffin wax embedded cervical tissue using a polyclonal antibody against recombinant p53. Microwave oven heating was used for antigen retrieval. Eight normal biopsy specimens, eight cases with histological features of HPV infection, and 49 cases of cervical intraepithelial neoplasia (CIN) were examined. Thirty one cases of CIN were examined. Thirty one cases of CIN were examined for evidence of HPV infection using in situ hybridisation with probes directed against wide spectrum HPV, HPV 16 and HPV 18. RESULTS: p53 immunoreactivity was seen in seven of eight (87%) of specimens with histological features of HPV infection, five of eight (62%) normal specimens, 13 of 22 (59%) CIN III, three of 14 (21%) CIN II and five of 13 (38%) CIN I specimens. The numbers of positive nuclei were small in cases of CIN and the location of positive nuclei within the epithelium paralleled the degree of dysplasia. Eleven of 15 (73%) CIN specimens which were immunoreactive for p53 yielded a positive signal for HPV by in situ hybridisation. A positive signal for HPV was also seen in 10 of 16 (63%) of CIN specimens in which p53 staining was absent. CONCLUSIONS: p53 immunoreactivity can be demonstrated in a small proportion of cells in the cervical squamous epithelium in a significant proportion of cases of CIN. This immunoreactivity seems to be independent of the presence of HPV, as assessed by in situ hybridisation. p53 immunoreactivity also occurs in non-neoplastic cervical squamous epithelium with a pattern of distribution within the epithelium which differs from that seen in CIN. Antigen retrieval by microwave oven heating enhances p53 immunostaining and may result in visualisation of cellular p53 in the absence of mutation.

Cervix Uteri↗
PubMed1994

A study of general innervation of the human adrenal cortex using PGP 9.5 immunohistochemistry.

Immunohistochemical detection of the neurone-specific ubiquitin hydrolase protein gene product 9.5 (PGP 9.5) has been applied to the normal adult human adrenal cortex to define overall patterns of innervation. Three distinct types of nerve morphology were noted in the cortex: large nerve trunks traversing the cortex to the medulla, a complex, branching network of slender nerve bundles and individual nerve fibres. These were more abundant in the head and body than in the alae and tail. Varicosities suggested local neurotransmitter release. Nerve fibres were also identified in the muscular wall of the central vein, which are apparently neither noradrenergic nor cholinergic. These data are in support of a direct role for nerves in the control of adrenocortical function and/or vascular responses in man.

Adrenal Cortex↗
PubMed1994

In the picture for learning. Use of pictorial learning for young children with diabetes.

1. Young children diagnosed as having diabetes need educating about their condition to enable them to self-care as early as possible. 2. Learning needs to be made fun for young children, and should preferably enable them to take an active role. 3. Pictorial cards can be used in a number of ways to help children learn, including games which can increase their motivation to learn.

Child↗
PubMed1993

Rab effector domain peptides stimulate the release of neurotransmitter from cell cultured synapses.

The involvement of the small GTP-binding protein rab3A in synaptic transmission was tested by presynaptic microinjection of guanine nucleotides and peptides corresponding to the effector domain of rab3A. When GTP gamma S injection was paired with presynaptic action potentials, the frequency of MIPSCs was increased and the evoked synaptic current was reduced in magnitude. To more specifically manipulate rab proteins, peptides were microinjected. Injection of the peptide rab3AL(33-48) or rab3(29-48) stimulated an increase in the frequency of MIPSC with little effect on action potential evoked synaptic transmission supporting a role for rab proteins in regulating synaptic transmission.

Action Potentials↗
PubMed1993

Roles for arachidonic acid and GTP-binding proteins in synaptic transmission.

Using synapses which form between somata of Helisoma neurons in cell culture we have studied the presynaptic regulation of synaptic transmission. GTP-binding proteins play important roles in regulating synaptic transmission through their actions on calcium currents, potassium currents and secretory apparatus. Heterotrimeric G proteins continuously regulate the amount of transmitter released at the synapse. By interacting with the arachidonic acid second messenger system they modulate potassium channels, and could potentially control the secretory apparatus. Perturbations of the rab protein system did not affect action potential-evoked transmission, but did control the frequency of miniature inhibitory postsynaptic currents. This is consistent with the involvement of this type of GTP-binding protein in the control of secretory apparatus, but suggests that rab proteins are not used to regulate the amount of transmitter released at the synapse. Using the Helisoma cellular system which permits direct access to the presynaptic site of transmitter release we are going on to study further the role of arachidonic acid, Go, Gi and rab proteins on the regulation of the secretory apparatus.

Amino Acid Sequence↗
PubMed1993

An investigation into the effects of hypoglycaemia in young people aged 16-30 years.

This study investigates the effects of hypoglycaemia on the working, social and personal lives of young people aged 16-30 years (mean age 23.9 years) who have insulin-treated diabetes mellitus. A total of 52 questionnaires were returned from a sample size of 70 subjects. Quantitative and qualitative analysis revealed that young people's lives are disrupted to varying degrees by hypoglycaemia. Hypoglycaemia and the complications of diabetes were found to be a source of concern to the subjects in the study, although 19 (36.5%) rarely carried out any self-monitoring. A more flexible approach to diabetic management is indicated, together with an agreed consensus of diabetic control between patients and professionals.

Adolescent↗
PubMed1993

Dietary intake of Al, Ca, Cu, Fe, Pb, and Zn in infants.

The dietary intake of six elements--Al, Ca, Cu, Fe, Pb, and Zn--was measured in 39 normal healthy children aged 17-61 (mean 35.5) weeks. There was a downward trend with age in daily intake of fluid, Pb and Fe, in contrast to an increase in solid intake, Ca and Zn throughout the study. The geometric mean total daily element intake (mg) was: Al 1.12; Ca 446; Cu 0.6; Fe 4.5; Pb 0.020; Zn 2.8. The geometric mean daily element intake (mg) from milks only was as follows: Formula milk (n = 14): Al 0.26; Ca 184; Cu 0.24; Fe 1.85; Pb 0.005; Zn 1.6. Cows' milk (n = 6): Al 0.27; Ca 384; Cu 0.04; Fe 0.21; Pb 0.004; Zn 1.3. Breast milk (n = 12): Al 0.77; Ca 116; Cu 0.15; Fe 0.38; Pb 0.012; Zn 0.4. Additionally, levels of aluminium were investigated in some packaged infant foodstuffs, including four soya milk formulae. The soya-based formulae had a mean concentration of 1.09 +/- 0.37 micrograms/g, which was not significantly different from the mean of 0.83 +/- 0.28 microgram/g for six cows' milk formulae.

Aluminum↗
PubMed1992

The distribution of immunoreactive interferon-gamma-containing cells in normal human tissues.

An immunohistochemical technique has been used to study the distribution of lymphocytes expressing interferon-gamma in normal adult tissues. The greatest concentrations of these cells were seen in mucosal sites exposed to a resident microflora. It is proposed that such organisms, by eliciting immune responses, provide the stimulus for the production of 'physiological' interferon-gamma. This in turn may act to preserve the 'tone' or readiness of the immune system.

Adult↗
PubMed1991

cAMP-stimulated phosphorylation of an axonemal polypeptide that copurifies with the 22S dynein arm regulates microtubule translocation velocity and swimming speed in Paramecium.

In Paramecium tetraurelia, cyclic nucleotides are important physiological second messengers that could regulate dynein mechanochemistry by phosphorylation. A 29-kDa polypeptide that is phosphorylated in a cAMP- and Ca(2+)-sensitive manner in permeabilized cells and isolated axonemes is the only significant phosphorylated moiety that consistently copurifies with 22S dynein from paramecium cilia. It is not a component of 14S dynein. This polypeptide can be thiophosphorylated in a cAMP-sensitive manner, and this form of 22S dynein is stable when stored at -70 degrees C. cAMP-mediated thiophosphorylation of the 29-kDa polypeptide significantly increases the velocity with which 22S dynein causes microtubules to glide in vitro. The increase is abolished, together with the thiophosphorylation of the 29-kDa polypeptide, by preincubation with high Ca2+. Pretreatment with high Ca2+ does not alter the thiophosphorylation pattern of, or the velocity of microtubule translocation by, 14S dynein. The same preincubation conditions that permit or abolish the increase in velocity of microtubule translocation by 22S dynein permit or fail to permit swimming speed of permeabilized cells to increase on reactivation even after cAMP is removed. The effect of cAMP on swimming speed can therefore be accounted for by changes in the mechanically coupled 22S dynein activity via phosphorylation or thiophosphorylation of the 29-kDa polypeptide, which could act as a regulatory dynein light chain.

Animals↗
PubMed1989

The safety and the efficacy of maintenance therapy of recombinant human erythropoietin in patients with renal insufficiency.

Ten anemic predialysis renal patients participated in a study to examine the long-term effects of recombinant human erythropoietin (r-HuEPO) treatment. The drug was initially given intravenously three times a week for 1 to 5 months, then by subcutaneous injections three times each week for 4 to 8 months, and finally by subcutaneous injection once weekly for 3 to 18 months. The duration of follow-up ranged from 11 to 29 months. Anemia was ameliorated in all participants. Mean hematocrit increased from a basal value of 26.8% to 35.1% during the intravenous phase and to 36.7% and 34.6% during the two subcutaneous periods. Mean weekly doses of erythropoietin (EPO) were 276 units/kg during intravenous therapy and 134 and 108 units/kg in the two subcutaneous periods. The differences in the doses were significant only between the intravenous and the two subcutaneous periods. Mean erythrocyte mass increased from a baseline value of 13.6 mL/kg to 20.4 mL/kg 8 months after initiation of treatment. Mean erythrocyte survival half-time was increased from 23 days before to 26 days, 8 months after r-HuEPO treatment, P less than 0.002. Mean blood pressure (mm Hg) was 105 before and 95 after treatment. Mean serum creatinine was 513 mumol/L (5.8 mg/dL) at the beginning of the study. At the time of this writing (11 to 29 months after treatment), seven patients have required dialysis treatment. There were three episodes of transient refractoriness to r-HuEPO documented during periods of infection and surgical procedures. All subjects tolerated the medication well, and no serious side effects attributable to the medication were noted. Furthermore, circulating antibodies against r-HuEPO were consistently negative.

Aged↗
PubMed1988

Transrectal ultrasound versus cystography in the evaluation of anatomical stress urinary incontinence.

Thirty-two female patients with clinical and urodynamic findings of genuine stress urinary incontinence were evaluated before and 6 months after surgery for stress urinary incontinence. Twenty-nine control patients had identical evaluations before and 6 months after surgery which did not involve the urethrovesical junction. Twenty-four patients with primary bladder instability had similar evaluations and served as a second control group. Anatomical landmarks indicating support to the urethrovesical junction were evaluated by the position of the urethra at the most dependent point in the bladder on straining and the urethral descent on straining to beneath the posterior ramus of the symphysis pubis on bead chain cystography. The urethrovesical junction drop on straining was evaluated by transrectal ultrasonography. Cystographic and ultrasonographic tests for the position of the urethrovesical junction at the most dependent position in the bladder during straining were very sensitive in women with stress urinary incontinence (94 and 87% respectively) but much less specific (45 and 48% respectively). When evaluating anatomical support to the urethrovesical junction and its descent on straining, these tests were both highly sensitive (97 and 94% respectively) and specific (76 and 96% respectively) in women with genuine stress urinary incontinence. Simple clinical tests for support of the urethrovesical junction, such as the Q tip test, are non-specific in patients with stress urinary incontinence. Transrectal ultrasonography is a simple and quick out-patient procedure. The availability of ultrasound equipment in most clinics and the high sensitivity and specificity of the test make it an attractive and cost-effective alternative to X-ray cystography in the pre-operative evaluation of anatomical support to the urethrovesical junction.

Adult↗