Pia Afzelius

Effect of Granulocyte Colony-Stimulating Factor (G-CSF) in Human Immunodeficiency Virus-Infected Patients: Increase in Numbers of Naive CD4 Cells and CD34 Cells Makes G-CSF a Candidate for Use in Gene Therapy or to Support Antiretroviral Therapy

The potential of granulocyte colony-stimulating factor (G-CSF) to mobilize CD4 cells and/or CD34 cells for use in gene therapy or to support antiretroviral therapy was examined. Ten human immunodeficiency virus-infected patients were treated with G-CSF (300 microg/day) for 5 days. Numbers of CD4 and CD34 cells were measured. To examine the numbers of naive and memory type CD4 cells, CD4 cell coexpression of CD45RA and CD45RO was measured. Functionality of mobilized CD4 cells was examined by use of the proliferation assay and interleukin-2 ELISA. The number of CD34 cells increased from 1.50 to 20.01/microL (P < .002). The CD4 cell count increased from 236 to 452/microL (P < .002). The CD45RA/CD45RO ratio increased from 0.50 to 0.57 (P < .03). Mobilized CD4 cells were functionally intact. In conclusion, G-CSF induced increases in numbers of CD34 cells and CD4 cells in HIV-infected patients. Furthermore, the fraction of naive CD4 cells increased. These findings have implications for the design of immunotherapy or gene therapy protocols.

Covalent modification of serum transferrin with phospholipid and incorporation into liposomal membranes.

A method is described for incorporation of water-soluble proteins into liposomal membranes using covalent protein-phospholipid conjugates in detergent solution. A disulfide derivative of phosphatidylethanolamine containing a reactive N-hydroxysuccinimide ester group is synthesized, and the derivative is reacted with serum transferrin in deoxycholate-containing buffer. Disulfide-linked transferrin-phosphatidylethanolamine conjugates containing up to 6 mol phospholipid/mol protein are prepared. The amphiphilic conjugates have solubility properties very similar to integral membrane proteins. The conjugates self-associate to form protein micelles of narrow size distribution (Stokes radii 6-7 nm), and in the presence of excess phospholipid (egg phosphatidylcholine), they readily incorporate into liposomal membranes upon removal of detergent. Stable incorporation into liposomes requires the introduction of two molecules of phosphatidylethanolamine into the transferrin. Using the disulfide linker to release transferrin from the liposomes, evidence is presented for a function of the phosphatidylethanolamine as an anchor-molecule into the liposomal lipid. Optimal conditions for preparation of homogeneous liposomes with diameters in the range 30-125 nm and with a varying content of transferrin are defined. The liposomes appear well suited for studies on liposome-cell membrane interactions.

Imaging of the major salivary glands

The major salivary glands, submandibular, parotid and sublingual glands play an important role in preserving the oral cavity and dental health. Patients with problems of the major salivary glands may present with symptoms such as dry mouth, dysphagia and obstruction of duct, inflammation, severe dental caries or swelling. Imaging plays an important role in visualization of morphology and function, to establish a diagnosis, for treatment, and for surgical planning. There are several options for diagnostic imaging: plain radiography, sialography, ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), salivary gland scintigraphy and 18F‐FDG positron emission tomography (PET). We present an overview of the modalities in relation to common salivary gland disease.

Pancreatic function and morphology in Sjögren's syndrome

Abstract Objective. Sjögrens syndrome (SS) is considered to be a universal exocrinopathy most likely based on autoimmune mechanisms. The degree of exocrine involvement in SS with the exception of salivary and lachrymal glands is, however, not yet established. Material and methods. We therefore examined the morphology, the exocrine and endocrine functions of the pancreas in 12 healthy consecutively included levolunteers with established SS, but without known pancreatic disease, using secretin-stimulated magnetic resonance cholangiopancreatography (MRCP), a Lundh test, oral glucose tolerance test, and blood sampling. Results. Twenty-five percent of the patients had morphological changes of pancreas as evaluated by secretin-stimulated MRCP, and two patients had chronic pancreatitis-like changes. Four patients had reduced exocrine function of the pancreas with either significantly reduced amylase and/or lipase in the pancreatic juice. Conclusions. The prevalence of pancreatic dysfunction was increased to 25–33% in the study population which is much higher than in the background population. Thus, pancreatic dysfunction and chronic pancreatitis should be considered in SS.

The serotonin analogue buspirone increases the function of PBMC from HIV-infected individuals in vitro.

HIV infection is characterized by the loss of CD4+ T cell numbers as well as loss of T cell function leading to severe immunodeficiency. The proliferative capacity of T cells, measured in vitro as response to antigens and mitogens, is severely reduced during HIV infection. An increased level of the intracellular second messenger cAMP has been demonstrated to cause impaired proliferative capacity of PBMC from HIV-infected individuals in vitro. We have identified a serotonin analogue, buspirone, that inhibits the activity of adenylyl cyclase, the enzyme responsible for regulation of intracellular levels of cAMP. Using this inhibitor the proliferative responses of PBMC to a polyclone activator in vitro were increased in 28/30 HIV-seropositive individuals (p < 0.00001). Further, we demonstrated that this was due to proliferation of CD4+ T cells and that buspirone induced expression of IL-2 mRNA.

A kinetic compartment model for evaluating salivary gland scintigraphies.

The semi‐quantitative analysis of salivary gland scintigraphy with 99mTc‐pertechnetate has been used to evaluate salivary gland function. However, no objective parameters distinguishing abnormal from normal functions have been established thus far. We propose using a simple kinetic model applied to the four major salivary glands. This kinetic model is based on a two‐compartment model and the assumption of first‐order kinetics to characterize normal salivary gland function and other selected parameters to evaluate the normal function of salivary glands.

Influence of Positron Emitters on Standard γ-Camera Imaging

Combined PET and SPECT scanning can give supplementary information. However, activity from PET radionuclides can cause background counts and increased dead time in γ camera imaging (SPECT or planar) because the 511-keV photons can penetrate collimators designed for lower energies. This study investigated how to manage this issue, including what levels of PET radionuclides can be tolerated when a γ-camera investigation is performed. Methods: Different combinations of 68Ga (PET radionuclide), 99mTc (low-energy radionuclide), and 111In (medium-energy radionuclide) were scanned by a γ camera. Standard low-, medium-, and high-energy collimators were used with the γ camera. Dead time and counts near and distant from the sources were recorded. Results: Down scatter from 511 keV can give rise to a considerable number of counts within the 99mTc or 111In energy windows, especially when the PET source is close to the camera head. Over the full camera head, the PET source can result in more counts per megabecquerel than the SPECT source (99mTc or 111In). Counts from the PET source were distributed over a large region of the camera head. With medium- and high-energy collimators, the sensitivity to the PET radionuclide was found to be about 10% of the sensitivity to 99mTc and about 20% of the sensitivity to 111In, as measured within a 3-cm-radius region of interest. Conclusion: If PET radionuclides of activity 1 MBq or higher are present in the patient at the time of SPECT, a medium-energy collimator should be used. Counts from PET sources will in SPECT usually be seen as a diffuse background rather than as foci. The thick septa of high-energy collimators may result in structure in the image, and a high-energy collimator is recommended only if PET activity is greater than 10 MBq.

Extra cardiac activity detected on myocardial perfusion scintigraphy after intra-arterial injection of 99mTc-MIBI.

Purpose:  We present an unusual case of extra cardiac activity of 99mTc‐MIBI in the left part of thorax and left upper extremity in a patient admitted for myocardial perfusion scintigraphy.

Improvement of Lymphocyte Proliferation in Human Immunodeficiency Virus Infection after Recombinant Interleukin-2 Treatment

In this study, the effect of recombinant interleukin-2 (rIL-2) on the function of peripheral blood mononuclear cells (PBMC) from human immunodeficiency virus (HIV)-infected patients was examined. Using polymerase chain reaction (PCR), an impaired ability of PBMC from 8 patients to respond upon mitogen stimulation with expression of IL-2 and IL-2 receptor (IL-2R) messenger ribonucleic acid (mRNA) was found compared with healthy donors (p = 0.02 and p = 0.05, respectively). Flow cytometry was used to determine the expression of p55 interleukin-2 alpha-receptor (CD25) after phytohaemagglutinin (PHA)-stimulation. Induced CD25 expression in response to stimulation was lower in patient cells than in donor cells (in CD4+ (p = 0.01) and in CD8+ (p = 0.03)). After rlL-2 treatment, the functionality of ex vivo expanded PBMC from patients was restored to the level found in donors. Finally, the induced gene expressions for IL-2 and IL-2R were positively correlated (p < 0.0001), suggesting that the activation of the IL-2 and IL-2R genes in humans may share a common activation pathway, as has been found in monkeys infected by simian immunodeficiency virus (SIV). These results indicate the existence of a reversible IL-2 and IL-2R defect at the pretranscriptional or transcriptional level in PBMC from patients. This may help explain the T-cell anergy found during HIV-infection.

Dual-energy X-ray Absorptiometry of Both Hips Helps Appropriate Diagnosis of Low Bone Mineral Density and Osteoporosis

Controversy still remains regarding the use of bilateral hip scanning when bone mineral density (BMD) is measured, and bilateral hip scanning is not mandatory in international guidelines for screening of osteoporosis. BMD of both hips and the lumbar spine was analyzed in 133 consecutive individuals. There were discrepancies between the lowest T-scores of both hips. Fourteen of the 133 participants (11%) were diagnosed with a poorer BMD status when the BMD of the hip of the dominant leg was analyzed. The total hip BMD of the dominant hip was lower than in the non-dominant hip, (p = 0.035), whereas there were no differences in the femoral neck area of the dominant and the non-dominant leg (p = 0.754). When classified by Z- or T-scores, there was consistency in 60 cases (45%) and inconsistency in 59 cases (44%). In 14 cases (11%), T- or Z-scores were the same, and it did not matter whether the non-dominant hip or the dominant hip had been chosen. A diagnostic discordance of 11% between the left and the right hip was observed when the lumbar spine was evaluated. The lowest Z- and T-scores of the hips were, in 44% of the cases, found in the hip of the assumed dominant leg. BMD measurements of both hips are recommended as clinical practice.