thy/liv-SCID-hu mice: a system for investigating the in vivo effects of multidrug therapy on plasma viremia and human immunodeficiency virus replication in lymphoid tissues

Modified, human immunodeficiency virus (HIV)-inoculated thy/liv-SCID-hu mice were used to evaluate the in vivo efficacy of antiretroviral drugs. Ritonavir treatment alone initially suppressed plasma viremia, but the viremia recurred with the appearance of ritonavir-resistant HIV isolates. Multidrug therapy suppressed plasma HIV RNA to undetectable levels; however, plasma viremia returned after therapy was stopped, showing that the therapy did not completely suppress HIV infection in the thymic implant. When thy/liv-SCID-hu mice were treated with a combination of zidovudine, lamivudine, and ritonavir immediately after inoculation with HIV, cocultures of the thymic implants remained negative for HIV even 1 month after therapy was discontinued, suggesting that acute treatment can prevent the establishment of HIV infection. Thus, these modified thy/liv-SCID-hu mice should prove to be a useful system for evaluating the effectiveness of different antiretroviral therapies on acute and chronic HIV infection.

About the origin of retroviruses and the co-evolution of the gypsy retrovirus with the Drosophila flamenco host gene

The gypsy element of Drosophila melanogaster is the first retrovirus identified so far in invertebrates. According to phylogenetic data, gypsy belongs to the same group as the Ty3 class of LTR-retrotransposons, which suggests that retroviruses evolved from this kind of retroelements before the radiation of vertebrates. There are other invertebrate retroelements that are also likely to be endogenous retroviruses because they share with gypsy some structural and functional retroviral-like characteristics. Gypsy is controlled by a Drosophila gene called flamenco, the restrictive alleles of which maintain the retrovirus in a repressed state. In permissive strains, functional gypsy elements transpose at high frequency and produce infective particles. Defective gypsy proviruses located in pericentromeric heterochromatin of all strains seem to be very old components of the genome of Drosophila melanogaster, which indicates that gypsy invaded this species, or an ancestor, a long time ago. At that time, Drosophila melanogaster presumably contained permissive alleles of the flamenco gene. One can imagine that the species survived to the increase of genetic load caused by the retroviral invasion because restrictive alleles of flamenco were selected. The characterization of a retrovirus in Drosophila, one of the most advanced model organisms for molecular genetics, provides us with an exceptional clue to study how a species can resist a retroviral invasion.

A new model of spinal cord edema

Edema of the spinal cord has not been well understood. Brain edema produced by Marmarou's infusion method is essentially similar to vasogenic edema. This infusion method for producing edema was applied to a cat spinal cord. After laminectomy, a 30-gauge needle was inserted into the intumescentia cervicalis. A total amount of 10 microliters of 2% Evans' blue or autoserum were infused using an infusion pump at a rate of 5 microliters/hr. Macroscopally, Evans' blue was observed in the vicinity of infused site at the same level of the needle insertion and was seen spreading mainly longitudinally in the lateral column for a certain distance. The extracellular space was markedly distended in the in fused white mater and filled with electron-dense materials which were thought to be proteins in the electron microscopic study. The fine structural features were similar to the findings which were seen in Marmarou's infusion type of brain edema. Using this model, it seems to be feasible to produce reproducible spinal cord edema at any location in order to investigate not only the morphological aspect but also physiological aspect of the edema.

Stabilization of Liquid Crystal-in-Water Dispersion with Polymer/Surfactant Mixture: Nematic Curvilinear Aligned Phase Composite Film

The effect of nonionic surfactant (H(OCH2-CH2)8-OC6H4-C9H19) on the stability of liquid crystal-in-water dispersions stabilized by copolymers of acrylamide with hydrophobic monomers have been studied. It was observed that the addition of surfactant increases the stability of liquid crystal (LC) dispersion and improves the electrooptical properties of the nematic curvilinear aligned phase (NCAP) system. According to the interfacial tension measurements, it was proposed that the presence of surfactant allows to form the nonpolar microenvironment in the round of LC droplet and finally reduces the anchoring effect between LC and the polymeric wall. Copyright 1998 Academic Press. Copyright 1998Academic Press

Thy/Liv-SCID-Hu mice implanted with human intestine: an in vivo model for investigation of mucosal transmission of HIV

Mucosal transmission is a major route by which individuals become infected with HIV. Investigation into the mechanism by which mucosal transmission of HIV occurs would be greatly facilitated by the development of a small animal model infectible with HIV by the mucosal route. We have previously described a SCID-hu mouse model, in which human thymic and liver tissues are implanted under both kidney capsules (thy/liv-SCID-hu mice), which are populated in the periphery with high numbers of human T cells and that develop disseminated HIV-1 infection after intraperitoneal injection. To expand further the usefulness of the thy/liv-SCID-hu mouse as a model for studying mucosal transmission of HIV, thy/liv-SCID-hu mice were subcutaneously implanted with human intestinal tissue in a manner that maintained the lumen. Four months later, the histological appearance of the implanted intestine resembled that of normal human bowel tissue and the lamina propria was populated with human T cells. Six weeks after introduction of HIV into the lumen of the intestinal implant, the mice developed disseminated HIV infection. Scattered HIV-infected cells were detected in the lamina propria of the implant, indicating that HIV infection in these mice was mediated by transmission of the virus across the mucosa of the human intestinal implant. Thus, our modified thy/liv-SCID-hu mice transplanted with human bowel tissue should provide a novel model for investigating mucosal transmission of HIV.

Mechanisms of reduced striatal NMDA excitotoxicity in type I nitric oxide synthase knock-out mice

We investigated the role of neuronal (type I) nitric oxide synthase (nNOS) in NMDA-mediated excitotoxicity in wild-type (SV129 and C57BL/6J) and type I NOS knock-out (nNOS-/-) mice and examined its relationship to apoptosis. Excitotoxic lesions were produced by intrastriatal stereotactic NMDA microinjections (10-20 nmol). Lesion size was dose- and time-dependent, completely blocked by MK-801 pretreatment, and smaller in nNOS knock-out mice compared with wild-type littermates (nNOS+/+, 11.7 +/- 1.7 mm3; n = 8; nNOS-/-, 6. 4 +/- 1.8 mm3; n = 7). The density and distribution of striatal NMDA binding sites, determined by NMDA receptor autoradiography, did not differ between strains. Pharmacological inhibition of nNOS by 7-nitroindazole (50 mg/kg, i.p.) decreased NMDA lesion size by 32% in wild-type mice (n = 7). Neurochemical and immunohistochemical measurements of brain nitrotyrosine, a product of peroxynitrite formation, were increased markedly in wild-type but not in the nNOS-/- mice. Moreover, elevations in 2,3- and 2,5-dihydroxybenzoic acid levels were significantly reduced in the mutant striatum, as a measure of hydroxyl radical production. The importance of apoptosis to NMDA receptor-mediated toxicity was evaluated by DNA laddering and by quantitative histochemistry [terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) staining]. DNA laddering was first detected within lesioned tissue after 12-24 hr. TUNEL-positive cells were first observed at 12 hr, increased in number at 48 hr and 7 d, and were located predominantly in proximity to the lesion border. The density was significantly lower in nNOS-/- mice. Hence, oligonucleosomal DNA breakdown suggesting apoptosis develops as a late consequence of NMDA microinjection and is reduced in nNOS mutants. The mechanism of protection in nNOS-/- mice may relate to decreased oxygen free radical production and related NO reaction products and, in part, involves mechanisms of neuronal death associated with the delayed appearance of apoptosis.

Saquinavir-mediated inhibition of human immunodeficiency virus (HIV) infection in SCID mice implanted with human fetal thymus and liver tissue: an in vivo model for evaluating the effect of drug therapy on HIV infection in lymphoid tissues

Treatment with protease inhibitors alone or in combination with inhibitors of reverse transcriptase potently suppresses levels of human immunodeficiency virus (HIV) RNA in plasma and thereby may significantly delay the progression of HIV-mediated disease. To investigate the effect of treatment with the protease inhibitor saquinavir on HIV replication in the lymphoid tissues, we used a SCID-hu mouse model that we developed, in which human thymic and liver tissues (hu-thy/liv) were implanted under both kidney capsules in SCID mice (thy/liv-SCID-hu mice). These mice are populated in the periphery with large numbers of human T cells and develop disseminated HIV infection after intraimplant injection. thy/liv-SCID-hu mice with established HIV infection that were treated for 1 month with saquinavir had a significantly lower viral load present in the implanted hu-thy/liv and mouse spleen than did the untreated HIV-infected thy/liv-SCID-hu mice. To examine the capacity of acute treatment with saquinavir to prevent HIV infection, some thy/liv-SCID-hu mice were inoculated with HIV and then immediately started on saquinavir. Although treated mice had markedly lower viral loads in the thy/liv implants and spleens, HIV infection was not completely prevented. Thus, the effect of antiviral therapy on HIV infection in the major site of HIV replication, the lymphoid tissues, can be readily evaluated in our thy/liv-SCID-hu mice. These mice should prove to be a useful model for determining the in vivo effectiveness of different therapeutic interventions on acute and chronic HIV infection.

Fidelity and mutational spectrum of Pfu DNA polymerase on a human mitochondrial DNA sequence

The study of rare genetic changes in human tissues requires specialized techniques. Point mutations at fractions at or below 10(-6) must be observed to discover even the most prominent features of the point mutational spectrum. PCR permits the increase in number of mutant copies but does so at the expense of creating many additional mutations or "PCR noise". Thus, each DNA sequence studied must be characterized with regard to the DNA polymerase and conditions used to avoid interpreting a PCR-generated mutation as one arising in human tissue. The thermostable DNA polymerase derived from Pyrococcus furiosus designated Pfu has the highest fidelity of any DNA thermostable polymerase studied to date, and this property recommends it for analyses of tissue mutational spectra. Here, we apply constant denaturant capillary electrophoresis (CDCE) to separate and isolate the products of DNA amplification. This new strategy permitted direct enumeration and identification of point mutations created by Pfu DNA polymerase in a 96-bp low melting domain of a human mitochondrial sequence despite the very low mutant fractions generated in the PCR process. This sequence, containing part of the tRNA glycine and NADH dehydrogenase subunit 3 genes, is the target of our studies of mitochondrial mutagenesis in human cells and tissues. Incorrectly synthesized sequences were separated from the wild type as mutant/wild-type heteroduplexes by sequential enrichment on CDCE. An artificially constructed mutant was used as an internal standard to permit calculation of the mutant fraction. Our study found that the average error rate (mutations per base pair duplication) of Pfu was 6.5 x 10(-7), and five of its more frequent mutations (hot spots) consisted of three transversions (GC-->TA, AT-->TA, and AT-->CG), one transition (AT-->GC), and one 1-bp deletion (in an AAAAAA sequence). To achieve an even higher sensitivity, the amount of Pfu-induced mutants must be reduced.

Effect of ovariectomy on the local residual ridge remodeling

STATEMENT OF PROBLEM

Osteoporosis and edentulism are two disease processes that affect a large group of elderly people in the United States (24 and 25 million, respectively). These two diseases are independent of each other; however, they have several pathologic symptoms in common, such as reduction in bone mass.

PURPOSE

The purpose of this study was to determine whether estrogen deficiency or its replacement therapy have any effect on the phenomenon of residual ridge remodeling.

MATERIAL AND METHODS

Three animal groups were formed that consisted of six female Sprague-Dawley rats each. The two groups had ovariectomy and received either a vehicle solution or a daily dose (1.5 micrograms/day) of 17 beta-estradiol delivered through osmotic pumps. The control group underwent sham surgery and received a vehicle solution. Animals were pair fed throughout the experiment. Unilateral molar extraction was performed in the maxilla, which produced a suitable site for examination of histologic characteristics and molecular biologic analyses. At the 4-week postextraction period the bone remodeling activity was noted at the surface of the residual ridge in the control group.

RESULTS

The ovariectomized group showed increased bone resorption activity, whereas the surface of the residual ridge alveolar bone of the ovariectomized and estrogen-treated group was covered by a layer of hyaline tissue. Poly(A)+ ribonucleic acid samples were isolated from the remodeling residual ridge tissues. Expression of alpha 2(I), alpha 1(II), alpha 1(IX), and alpha 2(X) collagens were examined by ribonucleic acid transfer dot blots. Compared with the control group, ovariectomized animals showed a reduction in bone formation with decreased expressions of type I and II collagens. In contrast, the estrogen-treatment group showed decreased formation of type I collagen with a much increased expression of type II collagen. Further examination of type II collagen formation on the ovariectomized and estrogen-treated group by means of in situ hybridization revealed the notable labeling by the type IIA collagen probe, which was associated with the surface tissue of the residual ridge alveolar bone.

CONCLUSION

These findings suggest that estrogen deficiency and its replacement therapy seem to affect the activity of residual ridge bone remodeling at the molecular level.

Urban-rural differences in prehospital care of major trauma

OBJECTIVES

To compare differences in response times, scene times, and transport times by advanced life-support-trained paramedics to trauma incidents in urban and rural locations.

METHODS

This report was a prospective cohort study of professional emergency medical services conducted in a five-county area in the state of Washington. Ninety-eight percent of trauma transports are provided by professional paramedics trained in advanced life support. Subjects were included in this study if they qualified as a major trauma victim and were transported or found dead at the scene by one of the region's advanced life support transport agencies between August 1, 1991, and January 31, 1992. The severity of injury was rated using the Prehospital Index. Incident locations were defined as "rural" if they occurred in a US Census division (a geographic area) in which more than 50% of the residents resided in a rural location.

RESULTS

During the 6-month data collection period, advanced life support agencies responded to a total of 459 major trauma victims in the region. A geographic locations was determined for 452 of these subjects. Of these, 42% of subjects were injured in urban areas and the remainder in rural areas. The severity of injuries, as determined both by the triage classification (p = 0.17) and the distribution of Prehospital Index scores (p = 0.92), was similar for urban and rural major trauma patients. Twenty-six (5.7%) subjects died at the scene. About one quarter of both groups had a severe injury, as indicated by Prehospital Index score of more than 3. The mean response time for urban locations was 7.0 minutes (median = 6 minutes) compared with 13.6 minutes (median = 12 minutes) for rural locations (p < 0.0001). The mean scene time in rural areas was slightly longer than in urban areas (21.7 vs. 18.7 minutes, p = 0.015). Mean transport times from the scene to the hospital were also significantly longer for rural incidents (17.2 minutes vs. 8.2 minutes, p < 0.0001). Rural victims were over seven times more likely to die before arrival (relative risk = 7.4, 95% confidence interval 2.4-22.8) if the emergency medical services' response time was more than 30 minutes.

CONCLUSIONS

Response and transport times among professional, advanced life-support-trained paramedics responding to major trauma incidents are longer in rural areas, compared with urban areas.

Perforated appendicitis within an inguinal hernia: case report and review of the literature

The finding of the vermiform appendix within an inguinal hernia sac is not uncommon. However, it is rare to find a perforated appendix within an inguinal hernia. An unusual case of an incarcerated and perforated appendix within an inguinal hernia complicated by an intra-abdominal abscess is reported herein. Perforated appendix as a cause of abscess was revealed during abdominal exploration. Clinicians are encouraged to be aware of this unusual entity, which is rarely recognized before exploration.

Three-vessel view of the fetal upper mediastinum: an easy means of detecting abnormalities of the ventricular outflow tracts and great arteries during obstetric screening

The three-vessel view is a transverse view of the fetal upper mediastinum is as simple to obtain as the four-chamber view. It demonstrates the main pulmonary artery, ascending aorta and superior vena cava in cross- or oblique sections. The purposes of this study were to describe the normal anatomy of the three-vessel view and to analyze what anatomical changes would occur in this view when there are lesions of the ventricular outflow tracts and/or great arteries. Sonograms of 29 fetuses with lesions involving the ventricular outflow tracts and/or great arteries were reviewed. Three-vessel views were evaluated in terms of vessel size, number, arrangement and alignment. Twenty-eight of 29 fetuses showed an abnormal three-vessel view that included abnormal vessel size (n = 12), abnormal alignment (n = 8), abnormal arrangement (n = 7) and abnormal vessel number (n = 3). The vessel size was abnormal in obstructive lesions of the right (n = 4) or the left (n = 8) side of the heart. An abnormal alignment was seen in tetralogy of Fallot (n = 6) and double-outlet right ventricle (n = 2) that showed anterior displacement of the aorta. An abnormal arrangement was seen in complete (n = 4) and corrected (n = 1) transposition, double-outlet right ventricle (n = 1) and pulmonary atresia with ventricular septal defect (n = 1). Only two vessels were seen in truncus arteriosus (n = 1). Four vessels were seen in persistent left superior vena cava (n = 2). A fetus with pulmonary atresia and intact ventricular septum showed a normal three-vessel view. In conclusion, most of the lesions involving the ventricular outflow tracts and/or great arteries showed an abnormal three-vessel view.

Severe combined immunodeficiency mice engrafted with human T cells, B cells, and myeloid cells after transplantation with human fetal bone marrow or liver cells and implanted with human fetal thymus: a model for studying human gene therapy

To develop an in vivo model wherein human hematopoiesis occurs, we transplanted severe combined immunodeficiency (SCID) mice with either human fetal bone marrow (HFBM) or human fetal liver (HFL). After transplantation of SCID mice with cultured HFBM (BM-SCID-hu mice) or HFL cells (Liv-SCID-hu mice), significant engraftment of the mouse bone marrow (BM) and population of the peripheral blood with human leukocytes was detected. Human colony-forming unit-granulocyte macrophage and burst forming unit-erythroid were detected in the BM of the BM-SCID-hu and Liv-SCID-hu mice up to 8 months after transplantation. When the HFBM or HFL cells were transduced with a retroviral vector before transplantation, integrated retroviral sequences were detected in human precursor cells present in the SCID mouse BM and in leukocytes circulating in the peripheral blood (PB) up to 7 months after transplantation. The PB of the BM-SCID-hu mice also became populated with human T cells after implantation with human thymic tissue, which provided a human microenvironment wherein human pre-T cells from the BM could mature. When the HFBM was retrovirally transduced before transplantation, integrated retrovirus was detected in sorted CD4+CD8+ double positive and CD4+ single positive cells from the thymic implant and CD4+ cells from the PB. Taken together, these data indicated that the BM of our BM-SCID-hu and Liv-SCID-hu mice became engrafted with retrovirally transduced human hematopoietic precursors that undergo the normal human hematopoietic program and populate the mouse PB with human cells containing integrated retroviral sequences. In addition to being a model for studying in vivo human hematopoiesis, these mice should also prove to be a useful model for investigating in vivo gene therapy using human stem/precursor cells.

Cellular antioxidant properties of human natural killer enhancing factor B

The protein, NKEF (natural killer enhancing factor), has been identified as a member of an antioxidant family of proteins capable of protecting against protein oxidation in cell-free assay systems. The mechanism of action for this family of proteins appears to involve scavenging or suppressing formation of protein thiyl radicals. In the present study we investigated the antioxidant protective properties of the NKEF-B protein overexpressed in an endothelial cell line (ECV304). Nkef-B-transfected cells displayed significantly lower levels of reactive oxygen species (ROS) compared with control or vector-transfected cells. Tert-Butylhydroperoxide-induced ROS was 15% lower in nkef-B-transfected cells and cytotoxicity was slightly, though not significantly, lower. NKEF-B had no effect on ROS induced by menadione or xanthine plus xanthine oxidase. NKEF-B overexpression resulted in slightly (approximately 10%) lower levels of cellular glutathione (GSH) and had no effect on rate or extent of GSH depletion following either diethylmaleate (DEM) or buthionine sulfoximine (BSO) treatment. Lipid peroxidation, assessed as thiobarbituric acid-reactive substances, was 40% lower in nkef-B-transfected cells compared with vector-only-transfected cells. DEM-induced lipid peroxidation was suppressed by NKEF-B at DEM concentrations of 20 microM to 1 mM. At 10 mM DEM, lipid peroxidation was unaffected by NKEF-B. NKEF-B expression also protected cells against menadione-induced inhibition of [3H]-thymidine uptake. The NKEF-B protein appears most effective in suppressing basal low-level oxidative injury such as that produced during normal metabolism. These results indicate that overexpression of the NKEF-B protein promotes resistance to oxidative stress in this endothelial cell line.

cDNA sequence and genomic structure of the murine p55 (Mpp1) gene

MPP1 is an X-linked human gene encoding a heavily palmitoylated membrane protein (p55) with homology to the Drosophila tumor suppressor gene lethal(1) discs-large. As a first step toward studying the effects of mutations in this gene in a mammalian system, the nucleotide sequence of the mouse Mpp1 cDNA has been determined along with the intron-exon boundaries. Mpp1 is ubiquitously expressed and encodes a p55 protein of 466 amino acids with 93 and 65% identity to the human and puffer fish (Fugu rubripes) p55 sequences, respectively. The genomic structure of the Mpp1 gene is likewise conserved with 12 exons. The location of the Mpp1 gene, on the X chromosome, is also conserved between the human and the mouse. Conservation of the Mpp1 gene between mouse and human gives support to the notion that construction and study of a mouse knockout model may help establish the function of the human MPP1 gene, a potential tumor suppressor gene.

An update on core needle biopsy for radiologically detected breast lesions

BACKGROUND

Traditionally, radiologically detected lesions of the breast have been evaluated by open surgical biopsy with wire localization. Recently, core needle biopsy has been introduced as an alternative to open surgical biopsy. The authors evaluated their own results with long term follow-up after core needle biopsy and reviewed the experience of other physicians with this new technique.

METHODS

Four hundred thirty-one core needle biopsies performed at UCLA were analyzed. The outcome of these cases was determined by either surgery or long term follow-up. Statistical analysis was performed to determine the accuracy of the method.

RESULTS

Definitive outcome was obtained in 96% of the core needle biopsy cases, with a median follow-up time of 18 months (range, 6-38 months). The authors achieved a sensitivity of 99% and a specificity of 100%. The false-negative rate was 1.7%. There were no complications in this series.

CONCLUSIONS

Core needle biopsy is a highly accurate and safe method for the diagnosis of radiologically detected lesions of the breast.

Evidence of cortical metabolic dysfunction in early Huntington's disease by single-photon-emission computed tomography

We compared perfusion of prefrontal, motor, and sensory cortices and basal ganglia in 29 Huntington's disease (HD) patients and nine controls. We found a significant reduction in perfusion in patients with HD of short (< 6 years, n = 10), medium (6-10 years, n = 8), and long duration (> 10 years, n = 11) compared with controls. Among short-duration patients, we observed decreases in cortical perfusion before evidence of atrophy on magnetic resonance imaging, suggesting that decreases in neuronal activity, as reflected by perfusion levels, precede gross structural changes. As expected, decreased perfusion was marked in basal ganglia. The extent of cortical perfusion correlated with clinical assessments of functional capabilities as well as with the duration of disease. Prefrontal perfusion correlated with cognitive measures, and motor cortical perfusion correlated with physical disability and activities of daily living scores. We found no significant clinical correlations with sensory cortical perfusion. Single-photon-emission computed tomography may be a sensitive method for assessing disease progression in clinical trials and pharmacologic intervention.

Role of protein kinase C-beta isozyme in activation of latent human immunodeficiency virus type 1 in promonocytic U1 cells by phorbol-12-myristate acetate

Protein kinase C (PKC) appears to play a role in replication of human immunodeficiency virus type 1 (HIV-1). PKC is a family of at least 12 isozymes. In this study, we investigated a role of Ca(2+)-dependent PKC isozymes (alpha, beta, and gamma) in activation of latent HIV-1 in U1, a chronically infected promonocytic cell line, using polyclonal rabbit anti-PKC isozyme antibodies as specific inhibitors. Antibodies were introduced intracellularly by electroporation and then cells were stimulated with PMA. HIV-1 production was measured as p24 antigen using ELISA and reverse transcriptase activity. Anti-PKC beta antibody significantly inhibited PMA-induced HIV-1 production, whereas antibodies against PKC alpha and gamma had no significant effect. Furthermore, anti-PKC beta antibody inhibited PMA-induced activation of NF-kappa B and HIV-1 LTR. Preincubation of anti-PKC beta antibody with its antigenic peptide reversed the inhibitory effect of anti-PKC beta antibody. This study suggest that PKC beta plays a role in PMA-induced activation of latent HIV-1.

SCID-hu mice: a model for studying disseminated HIV infection

Modifications that we introduced into the implantation of human fetal thymus and liver into SCID mice (thy/liv-SCID-hu mice) markedly increased the population of human T cells and monocytes present in the peripheral blood and peripheral lymphoid compartment of these mice. As a result, the modified thy/liv-SCID-hu mice developed disseminated HIV infection after intraimplant or i.p. inoculation. After chronic HIV infection of these mice, depletion of the peripheral human T cells was observed as reported in HIV-infected individuals. In addition, these mice also developed plasma viremia after infection with HIV. The peripheral blood mononuclear cells were responsive to in-vivo cytokine regulation as evidenced by induction of human IFN-gamma gene expression by human IL-12 and inhibition by human IL-10. Acute treatment with human IL-10 but not with human IL-12 inhibited the development of plasma viremia and HIV infection in thy/liv-SCID-hu mice inoculated with HIV-1(59), a clinical isolate. SCID mice transplanted with cultured human fetal bone marrow displayed significant engraftment of the mouse bone marrow with human precursor cells and population of the peripheral blood with human B cells and monocytes. The peripheral blood of these bone marrow-transplanted SCID mice also became populated with human T cells after they were implanted with human thymic tissue due to migration of human precursor cells from the mouse bone marrow to the implanted human thymus. Thus, these modified SCID-hu mice should prove to be a valuable in-vivo model for studying the immunopathogenesis of HIV infection and for examining the in-vivo efficacy of immunomodulatory, drug and gene therapy in modifying HIV infection.

Quantitative comparison of multiple myeloma tumor contamination in bone marrow harvest and leukapheresis autografts

Autologous transplantation is increasingly being used to treat patients with multiple myeloma (MM). Recently, peripheral blood progenitor cell (PBPC) harvest have been preferred over autologous bone marrow (BM) harvests due to reduced engraftment time, ease of attainment, and presumptive reduction of occult tumor involvement. To resolve this latter assumption quantitatively, we have used the unique immunoglobulin (Ig) heavy chain variable region sequence of the patient's myeloma cell as a marker of clonality. Samples from PBPC collections and 'back-up' BM harvests were obtained from 13 patients with MM and analyzed for tumor contamination using patient-specific oligonucleotide primers and the polymerase chain reaction. As expected, the percentage of tumor cells contaminating the BM harvest (median, 0.74%) was higher than in the PBPC specimens (median, 0.0024%). Because of the increased total number of cells required for PBPC transplantation, the increase in total number of contaminating cells in the BM vs PBPC autografts was less pronounced, (BM:PBPC tumor contamination ratios ranging from 0.9 to > 4500; median, 14). This confirms that in most but not all cases unmanipulated PBPC products are preferable over BM harvests as a method of reducing myeloma autograft tumor contamination.

Lamellar body count in amniotic fluid as a rapid screening test for fetal lung maturity

We conducted a 2-year prospective clinical outcome study to evaluate the usefulness of amniotic fluid lamellar body count (LBC) as a screening test for fetal lung maturity. During the interval under study, outcomes of 170 neonates were used to evaluate the test; 14 neonates had respiratory distress syndrome (RDS). Both LBC and lecithin-sphingomyelin ratio (L/S ratio) test results were available in 129 cases. All the cases of RDS had LBC of 50,000/microliter or less and L/S ratio of 2.8 or less; 72.7% of cases with no RDS had LBC greater than 50,000/microliter, and 80.4% of normal cases had L/S ratio higher than 2.8. LBC test results showed good correlation with L/S ratio test results between 26 weeks and 33 weeks of gestation (r = 0.78, p < 0.0001). With the cutoff value of 50,000/microliter for LBC, the diagnostic sensitivity and specificity were 100% and 80%, respectively. Determining LBC by cell counter is justified as a useful rapid initial screening test for the assessment of fetal lung maturity.

Inhibition of acute in vivo human immunodeficiency virus infection by human interleukin 10 treatment of SCID mice implanted with human fetal thymus and liver

To improve the usefulness of in vivo mode for the investigation of the pathophysiology of human immunodeficiency virus (HIV) infection, we modified the construction of SCID mice implanted with human fetal thymus and liver (thy/liv-SCID-hu mice) so that the peripheral blood of the mice contained significant numbers of human monocytes and T cells. After inoculation with HIV-1(59), a primary patient isolate capable of infecting monocytes and T cells, the modified thy/liv-SCID-hu mice developed disseminated HIV infection that was associated with plasma viremia. The development of plasma viremia and HIV infection in thy/liv-SCID-hu mice inoculated with HIV-1(59) was inhibited by acute treatment with human interleukin (IL) 10 but not with human IL-12. The human peripheral blood mononuclear cells in these modified thy/liv-SCID-hu mice were responsive to in vivo treatment with exogenous cytokines. Human interferon gamma expression in the circulating human peripheral blood mononuclear cells was induced by treatment with IL-12 and inhibited by treatment with IL-10. Thus, these modified thy/liv-SCID-hu mice should prove to be a valuable in vivo model for examining the role of immunomodulatory therapy in modifying HIV infection. Furthermore, our demonstration of the vivo inhibitory effect of IL-10 on acute HIV infection suggests that further studies may be warranted to evaluate whether there is a role for IL-10 therapy in preventing HIV infection in individuals soon after exposure to HIV such as for children born to HIV-infected mothers.

Molecular analysis of a silent polymorphism in the PDZ domain of p55, the major palmitoylated erythrocyte membrane protein

Two independently published cDNA sequences of p55, the X-linked major palmitoylated erythrocyte membrane protein, revealed a discrepancy between G and T at position 358 (Genbank: M64925). This results in codon 85, in exon 3 in the PDZ (PSD-95, discs-large, Z0-1) domain, being either ACG or ACT. As both ACG and ACT code for threonine, this represents a silent polymorphism. Polymerase chain reaction (PCR), single-stranded conformational polymorphism (SSCP), and direct-sequencing analysis of exon 3 of the p55 gene was performed in 98 subjects of African and European origin. Of the 70 females studied, the frequency of G versus T at position 358 was 0.76:0.24, while of the 28 males, 16 had a G and 12 a T at position 358 (0.57:0.43). In subjects of African origin, the frequency of G versus T at position 358 was 0.78:0.22; in subjects of European origin the ratio was 0.63:0.37.