Comparison of fine-needle aspiration techniques

BACKGROUND

Fine-needle aspiration (FNA) has been reported since 1912 beginning with the use of trocars and other specialized instruments that were impractical. Since then, FNA has proven to be a successful alternative technique to excisional biopsy for some assays despite a few limitations.

METHODS

In this study, we compared four different techniques for FNA in rhesus macaques by evaluating total live cells recovered and cell viability using a standard 6 mL syringe and 1.5-inch 22-gauge needle.

RESULTS

Technique B which was the only technique in which the needle was removed from the syringe after collection of the sample to allow forced air through the needle to expel the contents into media followed by flushing of the syringe and needle resulted in the highest total cell count and second highest cell viability in recovered cells.

CONCLUSION

Based on our results, Technique B appears to be the superior method.

The Impact of SIV-Induced Immunodeficiency on Clinical Manifestation, Immune Response, and Viral Dynamics in SARS-CoV-2 Coinfection

Persistent and uncontrolled SARS-CoV-2 replication in immunocompromised individuals has been observed and may be a contributing source of novel viral variants that continue to drive the pandemic. Importantly, the effects of immunodeficiency associated with chronic HIV infection on COVID-19 disease and viral persistence have not been directly addressed in a controlled setting. Here we conducted a pilot study wherein two pigtail macaques (PTM) chronically infected with SIVmac239 were exposed to SARS-CoV-2 and monitored for six weeks for clinical disease, viral replication, and viral evolution, and compared to our previously published cohort of SIV-naïve PTM infected with SARS-CoV-2. At the time of SARS-CoV-2 infection, one PTM had minimal to no detectable CD4+ T cells in gut, blood, or bronchoalveolar lavage (BAL), while the other PTM harbored a small population of CD4+ T cells in all compartments. Clinical signs were not observed in either PTM; however, the more immunocompromised PTM exhibited a progressive increase in pulmonary infiltrating monocytes throughout SARS-CoV-2 infection. Single-cell RNA sequencing (scRNAseq) of the infiltrating monocytes revealed a less activated/inert phenotype. Neither SIV-infected PTM mounted detectable anti-SARS-CoV-2 T cell responses in blood or BAL, nor anti-SARS-CoV-2 neutralizing antibodies. Interestingly, despite the diminished cellular and humoral immune responses, SARS-CoV-2 viral kinetics and evolution were indistinguishable from SIV-naïve PTM in all sampled mucosal sites (nasal, oral, and rectal), with clearance of virus by 3-4 weeks post infection. SIV-induced immunodeficiency significantly impacted immune responses to SARS-CoV-2 but did not alter disease progression, viral kinetics or evolution in the PTM model. SIV-induced immunodeficiency alone may not be sufficient to drive the emergence of novel viral variants.

A combined adjuvant approach primes robust germinal center responses and humoral immunity in non-human primates

Adjuvants and antigen delivery kinetics can profoundly influence B cell responses and should be critically considered in rational vaccine design, particularly for difficult neutralizing antibody targets such as human immunodeficiency virus (HIV). Antigen kinetics can change depending on the delivery method. To promote extended immunogen bioavailability and to present antigen in a multivalent form, native-HIV Env trimers are modified with short phosphoserine peptide linkers that promote tight binding to aluminum hydroxide (pSer:alum). Here we explore the use of a combined adjuvant approach that incorporates pSer:alum-mediated antigen delivery with potent adjuvants (SMNP, 3M-052) in an extensive head-to-head comparison study with conventional alum to assess germinal center (GC) and humoral immune responses. Priming with pSer:alum plus SMNP induces additive effects that enhance the magnitude and persistence of GCs, which correlate with better GC-TFH cell help. Autologous HIV-neutralizing antibody titers are improved in SMNP-immunized animals after two immunizations. Over 9 months after priming immunization of pSer:alum with either SMNP or 3M-052, robust Env-specific bone marrow plasma cells (BM BPC) are observed. Furthermore, pSer-modification of Env trimer reduce targeting towards immunodominant non-neutralizing epitopes. The study shows that a combined adjuvant approach can augment humoral immunity by modulating immunodominance and shows promise for clinical translation.

Duration of antiretroviral therapy impacts the degree of residual SIV infection in the gut in long-term non-progressing Chinese rhesus macaques

The gut is a major reservoir in HIV-infected individuals on antiretroviral therapy (ART) and in long-term non-progressors (LTNPs). Whether ART reduces gut infection and reservoirs in LTNPs is unknown. Herein, SIV-infected LTNP Rhesus macaques were treated with short- or long-term ART, and SIV envelope gp120 sequences obtained from single genome amplification were analyzed before and after ART in peripheral blood and the intestine. Although ART does not eliminate SIV in these LTNPs, a longer ART period dramatically reduces SIV infection in the gut. This study highlights the importance of long-term ART in LTNPs to minimize gut infection and prolong remission.

Long-primed germinal centres with enduring affinity maturation and clonal migration

Germinal centres are the engines of antibody evolution. Here, using human immunodeficiency virus (HIV) Env protein immunogen priming in rhesus monkeys followed by a long period without further immunization, we demonstrate germinal centre B (BGC) cells that last for at least 6 months. A 186-fold increase in BGC cells was present by week 10 compared with conventional immunization. Single-cell transcriptional profiling showed that both light- and dark-zone germinal centre states were sustained. Antibody somatic hypermutation of BGC cells continued to accumulate throughout the 29-week priming period, with evidence of selective pressure. Env-binding BGC cells were still 49-fold above baseline at 29 weeks, which suggests that they could remain active for even longer periods of time. High titres of HIV-neutralizing antibodies were generated after a single booster immunization. Fully glycosylated HIV trimer protein is a complex antigen, posing considerable immunodominance challenges for B cells1,2. Memory B cells generated under these long priming conditions had higher levels of antibody somatic hypermutation, and both memory B cells and antibodies were more likely to recognize non-immunodominant epitopes. Numerous BGC cell lineage phylogenies spanning more than the 6-month germinal centre period were identified, demonstrating continuous germinal centre activity and selection for at least 191 days with no further antigen exposure. A long-prime, slow-delivery (12 days) immunization approach holds promise for difficult vaccine targets and suggests that patience can have great value for tuning of germinal centres to maximize antibody responses.

Neuroinflammatory Profiling in SIV-Infected Chinese-Origin Rhesus Macaques on Antiretroviral Therapy

The central nervous system (CNS) HIV reservoir is an obstacle to achieving an HIV cure. The basal ganglia harbor a higher frequency of SIV than other brain regions in the SIV-infected rhesus macaques of Chinese-origin (chRMs) even on suppressive combination antiretroviral therapy (ART). Since residual HIV/SIV reservoir is associated with inflammation, we characterized the neuroinflammation by gene expression and systemic levels of inflammatory molecules in healthy controls and SIV-infected chRMs with or without ART. CCL2, IL-6, and IFN-γ were significantly reduced in the cerebrospinal fluid (CSF) of animals receiving ART. Moreover, there was a correlation between levels of CCL2 in plasma and CSF, suggesting the potential use of plasma CCL2 as a neuroinflammation biomarker. With higher SIV frequency, the basal ganglia of untreated SIV-infected chRMs showed an upregulation of secreted phosphoprotein 1 (SPP1), which could be an indicator of ongoing neuroinflammation. While ART greatly reduced neuroinflammation in general, proinflammatory genes, such as IL-9, were still significantly upregulated. These results expand our understanding of neuroinflammation and signaling in SIV-infected chRMs on ART, an excellent model to study HIV/SIV persistence in the CNS.

Chronic binge alcohol and ovariectomy-mediated impaired insulin responsiveness in SIV-infected female rhesus macaques

Aging people living with HIV (PLWH), especially postmenopausal women may be at higher risk of comorbidities associated with HIV, antiretroviral therapy (ART), hypogonadism, and at-risk alcohol use. Our studies in simian immunodeficiency virus (SIV)-infected male macaques demonstrated that chronic binge alcohol (CBA) reduced acute insulin response to glucose (AIRG), and at-risk alcohol use decreased HOMA-β in PLWH. The objective of this study was to examine the impact of ovariectomy (OVX) on glucose-insulin dynamics and integrity of pancreatic endocrine function in CBA/SIV-infected female macaques. Female macaques were administered CBA (12-15 g/kg/wk) or isovolumetric water (VEH) intragastrically. Three months after initiation of CBA/VEH administration, all macaques were infected with SIVmac251, and initiated on antiretroviral therapy (ART) 2.5 mo postinfection. After 1 mo of ART, macaques were randomized to OVX or sham surgeries (n = 7 or 8/group), and euthanized 8 mo post-OVX (study endpoint). Frequently sampled intravenous glucose tolerance tests (FSIVGTT) were performed at selected time points. Pancreatic gene expression and islet morphology were determined at study endpoint. There was a main effect of CBA to decrease AIRG at Pre-SIV and study endpoint. There were no statistically significant OVX effects on AIRG (P = 0.06). CBA and OVX decreased the expression of pancreatic markers of insulin docking and release. OVX increased endoplasmic stress markers. CBA but not OVX impaired glucose-insulin expression dynamics in SIV-infected female macaques. Both CBA and OVX altered integrity of pancreatic endocrine function. These findings suggest increased vulnerability of PLWH to overt metabolic dysfunction that may be exacerbated by alcohol use and ovarian hormone loss.

Co-immunization of DNA and Protein in the Same Anatomical Sites Induces Superior Protective Immune Responses against SHIV Challenge

We compare immunogenicity and protective efficacy of an HIV vaccine comprised of env and gag DNA and Env (Envelope) proteins by co-administration of the vaccine components in the same muscles or by separate administration of DNA + protein in contralateral sites in female rhesus macaques. The 6-valent vaccine includes gp145 Env DNAs, representing six sequentially isolated Envs from the HIV-infected individual CH505, and matching GLA-SE-adjuvanted gp120 Env proteins. Interestingly, only macaques in the co-administration vaccine group are protected against SHIV CH505 acquisition after repeated low-dose intravaginal challenge and show 67% risk reduction per exposure. Macaques in the co-administration group develop higher Env-specific humoral and cellular immune responses. Non-neutralizing Env antibodies, ADCC, and antibodies binding to FcγRIIIa are associated with decreased transmission risk. These data suggest that simultaneous recognition, processing, and presentation of DNA + Env protein in the same draining lymph nodes play a critical role in the development of protective immunity.

Beneficial Effects of Human Anti-Interleukin-15 Antibody in Gluten-Sensitive Rhesus Macaques with Celiac Disease

Overexpression of interleukin-15 (IL-15) is linked with immunopathology of several autoimmune disorders including celiac disease. Here, we utilized an anti-human IL-15 antibody 04H04 (anti-IL-15) to reverse immunopathogenesis of celiac disease. Anti-IL-15 was administered to six gluten-sensitive rhesus macaques with celiac disease characteristics including gluten-sensitive enteropathy (GSE), and the following celiac-related metrics were evaluated: morphology (villous height/crypt depth ratio) of small intestine, counts of intestinal intraepithelial lymphocytes, IFN-γ-producing CD8+ and CD4+ T cells, plasma levels of anti-gliadin and anti-intestinal tissue transglutaminase IgG antibodies, as well as peripheral effector memory (CD3+CD28-CD95+) T cells. Anti-IL-15 treatment reversed the clinically relevant disease endpoints, intraepithelial lymphocyte counts, and villous height/crypt depth ratios within jejunal biopsies to normal levels (P < 0.001). Additionally, intestinal CD8+ and CD4+ T cell IFN-γ production was reduced (P < 0.05). Extra-intestinally, anti-IL-15 treatment reduced peripheral NK cell counts (P < 0.001), but otherwise, non-NK peripheral lymphocytes including effector memory T cells and serum blood chemistry were unaffected. Overall, providing the beneficial disease-modulatory and immunomodulatory effects observed, anti-IL-15 treatment might be considered as a novel therapy to normalize intestinal lymphocyte function in celiac disease patients with GSE.

Hydrocephalus after Intrathecal Administration of Dextran to Rhesus Macaques (Macaca mulatta)

Dextrans have been used extensively as medical therapies and labeling agents in biomedical research to investigate the blood-brain barrier and CSF flow and absorption. Adverse effects from dextrans include anaphylactic reaction and dilation of the cerebral ventricles due to administration into the subarachnoid space. This retrospective study describes 51 rhesus macaques (Macaca mulatta) that received dextran intrathecally. The purpose of intrathecal administration was to enable detection of long-lived, dextran-labeled macrophages and to study monocyte-macrophage turnover in the CNS of SIV- or SHIV- infected and uninfected animals by using immunofluorescence. Of the 51 dextran-treated macaques, 8 that received dextran diluted in saline developed hydrocephalus; 6 of these 8 animals exhibited neurologic signs. In contrast, none of the macaques that received intrathecal dextran diluted in PBS developed hydrocephalus. These data suggest the use of saline diluent and the duration of dextran exposure as potential factors contributing to hydrocephalus after intrathecal dextran in rhesus macaques.

Pseudoaneurysm and Arteriovenous Fistula in a Rhesus Macaque (Macaca mulatta)

An 8-y-old female rhesus macaque (Macaca mulatta) presented for swelling of the left lower limb distal to the inguinal region and associated with the femoral artery. Physical and ultrasound examinations suggested an arteriovenous fistula combined with a pseudoaneurysm. After review of possible treatment options, we determined that open surgical repair was the best course of action. The pseudoaneurysm and arteriovenous fistula were surgically resected, and the macaque recovered without complication.

Chronic binge alcohol administration impairs glucose-insulin dynamics and decreases adiponectin in asymptomatic simian immunodeficiency virus-infected macaques

Alcohol use disorders (AUDs) frequently exist among persons living with HIV/AIDS. Chronic alcohol consumption, HIV infection, and antiretroviral therapy (ART) are independently associated with impairments in glucose-insulin dynamics. Previous studies from our laboratory have shown that chronic binge alcohol (CBA) administration decreases body mass index, attenuates weight gain, and accentuates skeletal muscle wasting at end-stage disease in non-ART-treated simian immunodeficiency virus (SIV)-infected male rhesus macaques. The aim of this study was to investigate whether CBA and ART alone or in combination alter body composition or glucose-insulin dynamics in SIV-infected male rhesus macaques during the asymptomatic phase of SIV infection. Daily CBA or sucrose (SUC) administration was initiated 3 mo before intrarectal SIV inoculation and continued until the study end point at 11 mo post-SIV infection. ART or placebo was initiated 2.5 mo after SIV infection and continued until study end point. Four treatment groups (SUC/SIV ± ART and CBA/SIV ± ART) were studied. CBA/SIV macaques had significantly decreased circulating adiponectin and resistin levels relative to SUC/SIV macaques and reduced disposition index and acute insulin response to glucose, insulin, and C-peptide release during frequently sampled intravenous glucose tolerance test, irrespective of ART status. No statistically significant differences were observed in homeostatic model assessment-insulin resistance values, body weight, total body fat, abdominal fat, or total lean mass or bone health among the four groups. These findings demonstrate CBA-mediated impairments in glucose-insulin dynamics and adipokine profile in asymptomatic SIV-infected macaques, irrespective of ART.

Pervasive supply of therapeutic lysosomal enzymes in the CNS of normal and Krabbe-affected non-human primates by intracerebral lentiviral gene therapy

Metachromatic leukodystrophy (MLD) and globoid cell leukodystrophy (GLD or Krabbe disease) are severe neurodegenerative lysosomal storage diseases (LSD) caused by arylsulfatase A (ARSA) and galactosylceramidase (GALC) deficiency, respectively. Our previous studies established lentiviral gene therapy (GT) as a rapid and effective intervention to provide pervasive supply of therapeutic lysosomal enzymes in CNS tissues of MLD and GLD mice. Here, we investigated whether this strategy is similarly effective in juvenile non-human primates (NHP). To provide proof of principle for tolerability and biological efficacy of the strategy, we established a comprehensive study in normal NHP delivering a clinically relevant lentiviral vector encoding for the human ARSA transgene. Then, we injected a lentiviral vector coding for the human GALC transgene in Krabbe-affected rhesus macaques, evaluating for the first time the therapeutic potential of lentiviral GT in this unique LSD model. We showed favorable safety profile and consistent pattern of LV transduction and enzyme biodistribution in the two models, supporting the robustness of the proposed GT platform. We documented moderate inflammation at the injection sites, mild immune response to vector particles in few treated animals, no indication of immune response against transgenic products, and no molecular evidence of insertional genotoxicity. Efficient gene transfer in neurons, astrocytes, and oligodendrocytes close to the injection sites resulted in robust production and extensive spreading of transgenic enzymes in the whole CNS and in CSF, leading to supraphysiological ARSA activity in normal NHP and close to physiological GALC activity in the Krabbe NHP, in which biological efficacy was associated with preliminary indication of therapeutic benefit. These results support the rationale for the clinical translation of intracerebral lentiviral GT to address CNS pathology in MLD, GLD, and other neurodegenerative LSD.

Effects of alcohol consumption on antigen-specific cellular and humoral immune responses to SIV in rhesus macaques

BACKGROUND

Simian immunodeficiency virus (SIV) infection in macaques chronically receiving ethanol results in significantly higher plasma viral loads and more rapid progression to end-stage disease. We thus hypothesized that the increased plasma viral load in ethanol-treated, SIV-infected macaques would negatively correlate with antigen-specific immune responses.

METHODS

Rhesus macaques were administered ethanol or sucrose (n = 12 per group) by indwelling gastric catheters for 3 months and then intravenously infected with SIVMAC251. Peripheral blood T- and B-cell immunophenotyping and quantification were performed. Plasma was examined for viremia, levels of SIVEnv-specific binding, and neutralizing antibodies. Virus-specific interferon γ and tumor necrosis factor α cytokine responses to SIV-Nef, Gag, or Env peptide pools were measured in peripheral blood CD8 T cells.

RESULTS

Macaques receiving ethanol had both higher plasma viremia and virus-specific cellular immune responses compared with the sucrose-treated group. The emergence of virus-specific cytokine responses temporally correlated with the decline in mean plasma viral load after 14 days postinfection in all SIV-infected animals. However, neither the breadth and specificity nor the magnitude of virus-specific CD8 T-cell responses correlated with early postpeak reductions in plasma viral loads. In fact, increased cytokine responses against Gag, gp120, and gp41 positively correlated with plasma viremia. Levels of SIV envelope-specific immunoglobulin G and neutralizing antibodies were similar over the disease course in both groups of macaques.

CONCLUSIONS

Persistently higher antigen-specific cytokine responses in animals receiving ethanol are likely an effect of the higher viral loads and antigen persistence, rather than a cause of the increased viremia.

Effect of bacterial pneumonia on lung simian immunodeficiency virus (SIV) replication in alcohol consuming SIV-infected rhesus macaques

BACKGROUND

Opportunistic infections in human immunodeficiency virus (HIV)-infected persons have been shown to increase the rate of HIV replication. In populations where prophylaxis against Pneumocystis pneumonia is utilized, bacterial pneumonia is now the leading cause of lower respiratory tract infection in HIV+ patients. Our prior studies have shown that chronic alcohol consumption in demarcated simian immunodeficiency virus (SIV)-infected rhesus macaques increases plasma viral load set point and accelerates progression to end-stage acquired immune deficiency syndrome. While chronic alcohol abuse is well known to increase the incidence and severity of bacterial pneumonia, the impact of alcohol consumption on local and systemic SIV/HIV burden during lung infection is unknown. Therefore, we utilized the macaque SIV infection model to examine the effect of chronic ethanol (EtOH) feeding on SIV burden during the course of pulmonary infection with Streptococcus pneumoniae, the most commonly identified etiology of bacterial pneumonia in HIV+ and HIV- persons in developed countries.

METHODS

Alcohol was administered starting 3 months before SIVmac251 inoculation to the end of the study via an indwelling intragastric catheter to achieve a plasma alcohol concentration of 50 to 60 mM. Control animals received isocaloric sucrose. Four months after SIV infection, the right lung was inoculated with 2 × 10(6) CFU S. pneumoniae.

RESULTS

Leukocyte recruitment into the lung, pulmonary bacterial clearance, and clinical course were similar between EtOH and control groups. While plasma SIV viral load was similar between groups postpneumonia, chronic EtOH-fed macaques showed a prolonged increase in SIV RNA in bronchoalveolar lavage fluid. Alveolar macrophages isolated from EtOH-fed macaques 1 day post-pneumonia showed greater nuclear factor kappa beta (NF-κB) activation.

CONCLUSIONS

This study indicates that chronic EtOH feeding results in enhanced local, but not systemic, SIV replication following pneumococcal pneumonia. Increased NF-κB activity in the setting of chronic EtOH ingestion may play a mechanistic role in this observation.

Excision of femoral head and neck for treatment of coxofemoral degenerative joint disease in a rhesus macaque (Macaca mulatta)

Nonhuman primates are a valuable model for osteoarthritis. Osteoarthritis has been extensively studied in nonhuman primates in both naturally occurring and induced disease states. However, little published information describes naturally occurring osteoarthritis of the coxofemoral joints of nonhuman primates. We report a case of naturally occurring coxofemoral joint osteoarthritis in a rhesus macaque. This case radiographically resembled hip dysplasia reported in other species and demonstrated a rapid progression in severity of lameness, with accompanying loss of muscle mass in the affected limb. We excised the femoral head and neck to alleviate the pain that accompanied the osteoarthritis. Physical therapy was initiated, and dual-energy X-ray absorptiometry and video recordings were performed to evaluate the macaque's response to surgical intervention. By 3 mo postoperatively, the macaque had regained full use of the affected limb.

Disrupted anabolic and catabolic processes may contribute to alcohol-accentuated SAIDS-associated wasting

BACKGROUND

Alcohol abuse is a comorbid factor in many human immunodeficiency virus (HIV)-infected patients. Previously, we demonstrated that chronic binge alcohol accentuates loss of body mass at terminal stage of simian immunodeficiency virus (SIV) infection. The purpose of this study was to investigate changes in pathways that may contribute to muscle wasting in chronic binge alcohol-fed SIV-infected macaques.

METHODS

The impact of chronic binge alcohol during SIV infection on insulin signaling and the ubiquitin (Ub)-proteasome system-regulators of protein synthesis and degradation-was examined in SIV-infected macaques.

RESULTS

SIV infection induced an inflammatory and pro-oxidative milieu in skeletal muscle, which was associated with decreased insulin-stimulated phosphatidylinositol 3-kinase (PI-3k) activity and upregulated gene expression of mTOR and atrogin-1, and protein expression of Ub-proteasome system 19S base. Chronic binge alcohol accentuated the skeletal muscle pro-oxidative milieu and 19S base expression. Additionally, chronic binge alcohol increased skeletal muscle protein expression of protein-tyrosine phosphatase 1B (a negative regulator of insulin signaling) and 19S proteasome regulator non-ATPase (Rpn) 6 subunit and Rpn12, and suppressed PI-3K activity. Animals that were alcohol-fed and SIV-infected for >15 months had increased Ub-proteasome system activity.

CONCLUSIONS

These data suggest negative modulation of insulin signaling coupled with enhanced Ub-proteasome system activity may be central mechanisms underlying chronic binge alcohol-induced accentuation of SIV-associated muscle wasting.

Comparison of efficacy of moxidectin and ivermectin in the treatment of Strongyloides fulleborni infection in rhesus macaques

BACKGROUND

Strongyloides infection may result in clinical disease or confound experimental protocols that utilize non-human primates. There is presently a Strongyloides fulleborni infection rate of approximately 27% in the Tulane National Primate Research Center's breeding colonies despite the routine therapeutic and prophylactic use of ivermectin.

METHODS

A study was conducted to determine if moxidectin treatment offers advantages to the intestinal parasite control program. A total of 150 rhesus macaques (Macaca mulatta) that were removed from the breeding colonies due to illness were selected for the study. The animals were randomly assigned to treatment groups with 75 receiving ivermectin and 75 receiving moxidectin. Egg counts were performed on fecal samples collected pre- and post-treatment.

RESULTS

Both treatments resulted in decreases in the number of eggs/g in the post-treatment sample as compared with the pre-treatment sample; however, no significant difference was found between treatment groups.

CONCLUSIONS

With the data demonstrating a similar efficacy in both ivermectin and moxidectin treated macaques, the benefit of moxidectin treatment relates to biosafety and topical application.

Fluctuations during growth of the plasma membrane H(+)-ATPase activity of Saccharomyces cerevisiae and Schizosaccharomyces pombe

The plasma membrane H(+)-ATPase activity was determined under various growth conditions using the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. Under early batch-growth conditions in a rich medium, the budding yeast S. cerevisiae ATPase specific activity increased 2- to 3-fold during exponential growth. During late exponential growth, a peak of ATPase activity, followed by a sudden decrease, was observed and termed "growth-arrest control". The growth arrest phenomenon of S. cerevisiae could not be related to the acidification of the culture medium or to glucose exhaustion in the medium or to variation of glucose activation of the H(+)-ATPase. Addition of ammonium to a proline minimum medium also stimulated transiently the ATPase activity of S. cerevisiae. Specific activity of the fission yeast S. pombe ATPase did not show a similar profile and steadily increased to reach a plateau in stationary growth. Under synchronous mitotic growth conditions, the ATPase activity of S. cerevisiae increased during the cell division cycle according to the "peak" type cycle, while that of S. pombe was of the "step" type.

Alcohol acetyltransferases and the significance of ester synthesis in yeast

This paper reviews our current knowledge of yeast alcohol acyltransferases. Much of this information has been gathered over the past 10 years through the application of powerful yeast molecular biology techniques. Evidence from gene disruption and expression analysis of members of the alcohol acyltransferase (ATF) gene family indicates that different ester synthases are involved in the synthesis of esters during alcoholic fermentation. The natural physiological rationale behind these enzyme activities remains unclear. However, it is believed that these enzymes may be involved in very different functions, including cellular fatty acid homeostasis and detoxification mechanisms. Insights into the regulation of yeast ester synthesis by oxygen and unsaturated fatty acids have contributed to our understanding of the general mechanisms of gene regulation. In particular, control mechanisms that underpin the oxygen-mediated regulation of ATF1 gene transcription appear to be closely linked to those involved in the regulation of fatty acid metabolism. Data pertaining to the regulation of ATF1 gene transcription have been integrated into a working model for future research.

Osteopenia, bone fragility and reflex sympathetic dystrophy syndrome in a man with ureterosigmoidostomy

A 68-year-old man is presented with a reflex sympathetic dystrophy syndrome (RSDS) of the right ankle diagnosed by radiography, magnetic resonance imaging and bone scintiscan. Investigations, including blood tests and bone biopsy, revealed a diagnosis of metabolic acidosis and osteomalacia. These appeared to result from a ureterosigmoidostomy performed 9 years previously for a transitional carcinoma of the bladder. Correction of the metabolic acidosis coincided with improvement in ankle pain. RSDS may be the initial presentation of osteomalacia, which in turn may be caused by the metabolic acidosis resulting from a ureterosigmoidostomy.

Amino acid replacements at seven different histidines in the yeast plasma membrane H(+)-ATPase reveal critical positions at His285 and His701

The plasma membrane H(+)-ATPase (Pmal) from Saccharomyces cerevisiae contains 14 histidine residues. The seven most highly conserved of these were selected as targets for oligonucleotide-directed, site-specific mutagenesis. Substitutions at H240, H488, H614, H686, and H914 with a variety of amino acid residues had no effect either on cell viability or on temperature and pH growth sensitivity. In contrast, substitutions at H701, located in the putative fifth membrane-spanning region, with Asp, Gln, or Arg were dominant lethal, indicating that H701 is essential for H(+)-ATPase activity. The mutations H285Q and H285R, but not H285E, located in the hydrophilic beta-stranded domain, were tolerated in normal growth conditions. Growth of H285Q mutants was sensitive to acid pH, indicating impaired in vivo ATPase activity. The H285Q and H285R mutants showed increased in vitro ATPase-specific activity, increased vanadate resistance, increased proton competition of vanadate sensitivity, accelerated ATP hydrolysis rates at a substrate concentration much lower than the Km, and slightly uncoupled proton pumping. The most reasonable hypothesis which would take into account these observations is that H285 would not be involved in the H+ transport process but rather in the E2 to E1 transition step of the ATP hydrolysis catalytic cycle.

Functional complementation of a null mutation of the yeast Saccharomyces cerevisiae plasma membrane H(+)-ATPase by a plant H(+)-ATPase gene

In plants, the proton pump-ATPase (H(+)-ATPase) of the plasma membrane is encoded by a multigene family. The presence within an organ of several isoforms prevents a detailed enzymatic characterization of individual H(+)-ATPases. We therefore used the yeast Saccharomyces cerevisiae as a heterologous host for the expression of PMA2, an H(+)-ATPase isoform of Nicotiana plumbaginifolia. Yeast transformed by the plant pma2 was still able to grow under conditions where the yeast ATPase gene (PMA1) was either repressed or deleted. The transformed yeast strain was resistant to hygromycin, and its growth was prevented when the medium pH was lowered to 5.0. The N. plumbaginifolia PMA2 expressed in S. cerevisiae has unusual low Km for ATP (23 microM) and high pH optimum (6.8). Electron microscopic examination revealed PMA2 in internal structures of the karmellae type which proliferated when cell growth was arrested, either at a nonpermissive pH or at the stationary phase in a minimal medium. Under the latter conditions, subcellular fractionation on sucrose gradients revealed, in addition to the expected plant PMA2 peak linked to the plasma membrane fraction, low density peak containing PMA2 and KAR2, an endoplasmic reticulum marker. These observations suggest that the partial internal accumulation of PMA2 occurs in membranes derived from the endoplasmic reticulum and largely depends on growth conditions.

[The self-aspirating syringe in local anesthesia]

Dentists routinely inject local anesthetic solutions in their daily practice. However, it is important not to inject intravascularly. Consequently, manufacturers offer two types of dental syringes: one with a mechanical aspirating device (harpoon) and the other with a self-aspirating mechanism. We have verified the efficacy of a self-aspirating syringe as presented on the market and another self-aspirating syringe which we lightly modified.

Short-chain and medium-chain aliphatic-ester synthesis in Saccharomyces cerevisiae

In the yeast Saccharomyces cerevisiae, the enzymes which catalyse the synthesis of ethyl acetate, ethyl n-hexanoate and isoamyl acetate were partly resolved from a fraction containing slowly sedimenting lipoproteins released during cell disruption with glass beads. Solubilization with detergents and fractionation by affinity chromatography have demonstrated the presence of at least three, and probably four, ester synthases which differ in their catalytic properties. Isoamyl-acetate synthase was solubilized and extensively purified to apparent homogeneity by successive chromatographies on various columns. On the basis of its specific activity in cell-free extracts, the enzyme was purified 19,000-fold with a 5% activity yield. As judged by SDS/PAGE, it consists of a single polypeptide chain with a molecular mass of 57 +/- 3 kDa and its apparent pI is 5.5. The enzyme acetylates isoamyl alcohol, ethanol and 12-DL-hydroxystearic acid from acetyl-CoA but is unable to use n-hexanoyl-CoA as a cosubstrate. This enzyme, defined as an acetyl-CoA: O-alcohol acetyltransferase, could be the product of one of the anaerobically induced genes in S. cerevisiae.

Purification and complete sequence of a small proteolipid associated with the plasma membrane H(+)-ATPase of Saccharomyces cerevisiae

The purified plasma membrane H(+)-ATPase of Schizosaccharomyces pombe and Saccharomyces cerevisiae display, in addition to the catalytic subunit of 100 kDa, a highly mobile component, soluble in chloroform/methanol. Chloroform/methanol extraction of S. cerevisiae plasma membranes led to isolation of a low molecular weight proteolipid identical to that present in purified H(+)-ATPase. NH2-terminal amino acid sequencing revealed a 38-residue polypeptide with a calculated molecular mass of 4250 Da. The polypeptide lacks the first two NH2-terminal amino acids as compared with the deduced sequence of the PMP1 gene (for plasma membrane proteolipid) isolated by hybridization with an oligonucleotide probe corresponding to an internal amino acid sequence of the proteolipid. The polypeptide is predicted to contain an NH2-terminal transmembrane segment followed by a very basic hydrophilic domain.

The yeast plasma membrane H(+)-ATPase. An essential change of conformation triggered by H+

The plasma membrane of Schizosaccharomyces pombe contains an H(+)-ATPase similar to the cation transport ATPases of other eukaryotic organisms. The fluorescence excitation and emission spectra of the purified H(+)-ATPase are characteristic of tryptophan residues. pH reduction from 7.5 to 5.7 produces a 4% decrease in fluorescence intensity, while a further reduction to pH 5.0 leads to an increase of fluorescence. A close correlation is observed between the pH dependence of the intrinsic fluorescence and the pH dependence of (i) ATPase activity, (ii) the fluorescence of Tb-formycin triphosphate bound to the active site, and (iii) inhibition by vanadate of ATPase activity. It is proposed that the effect of pH on intrinsic fluorescence reveals the existence of an H+ induced conformational change of the H(+)-ATPase similar to the E1----E2 transition of the other plasma membrane cation transport ATPases.

[Nonfunctioning nesidioblastoma of the pancreas in children. Apropos of a case]

A new case of nonfunctional nesidioblastoma in a 13-year-old girl is reported. The diagnosis was made with imaging, including radiographs of the abdomen, ultrasound and computed tomography. Complete resection of the pancreatic tumor was possible. The patient has no symptoms 8 months later.

[Loss of digital substance in rheumatic diseases. Apropos of 43 cases]

The authors briefly summarize 16 cases involving digital necrosis observed in the course of rheumatic disorders (3 carpal tunnel syndromes, 2 cases of panarteritis, 2 of rheumatoid arthritis, 2 of lupus erythematosus, 2 of scleroderma, 2 of dermatomyositis, 1 of adult form of Still's disease, 1 of gout, and 1 case of cryoglobulinemia). In addition the case reports of 129 patients with connective tissue disease were reviewed (74 cases of disseminated lupus erythematosus, 43 of scleroderma, and 12 mixed connective tissue disorders). Soft tissue destruction of digits was observed in 15, 39 and 25% of these patients respectively, and true tissue necrosis of varying extent in 7, 9 and 0% of these cases. The incidence and pathogenic mechanisms responsible for these disorders and lesions were discussed.

New modes of administration of salmon calcitonin in Paget's disease. Nasal spray and suppository

In volunteers the activity of various doses of a nasal spray and of a suppository of salmon calcitonin was compared to a placebo and to the parenteral route of administration. Both new modes of administration were found to be active on the kidney (and the suppository was found to affect bone turnover as well). The parenteral route proved more effective, but the nasal and/or rectal routes were devoid of systemic side effects and had minimal local intolerance. The nasal spray was used at 200 units daily in 15 patients with Paget's disease, and at 400 units daily in another nine patients, both trials lasting one year. The two regimens proved active on the parameters of bone turnover and the higher dose was more effective than the lower one. Similarly, a 300 unit suppository was given to another 12 patients. This trial is still being completed at this time. At the third month of therapy, the parameters of bone turnover were significantly depressed. Both new modes of therapy were able to improve the focal bone balance of the osteolytic lesions monitored on sequential roentgenograms. Systemic side effects were absent and local side effects were minimal. Only one patient interrupted the nasal spray therapy, and no one interrupted the suppository therapy.

Study of the nucleotide binding site of the yeast Schizosaccharomyces pombe plasma membrane H+-ATPase using formycin triphosphate-terbium complex

The plasma membrane of yeasts contains an H+-ATPase similar to the other cation transport ATPases of eukaryotic organisms. This enzyme has been purified and shows H+ transport in reconstituted vesicles. In the presence of Mg2+, formycin triphosphate (FTP) is hydrolyzed by the H+-ATPase and supports H+ transport. When combined with terbium ion, FTP (Tb-FTP) and ATP (Tb-ATP) are no longer hydrolyzed. Competition between Mg-ATP and Tb-FTP for ATP hydrolysis indicates that terbium-associated nucleotides bind to the catalytic site of the H+-ATPase. The fluorescent properties of the Tb-FTP complex were used to study the active site of the H+-ATPase. Fluorescence of Tb-FTP is greatly enhanced upon binding into the nucleotide site of H+-ATPase with a dissociation constant of 1 microM. Tb-ATP, Tb-ADP, and Tb-ITP are competitive inhibitors of Tb-FTP binding with Ki = 4.5, 5.0, and 6.0 microM, respectively. Binding of Tb-FTP is observed only in the presence of an excess of Tb3+ with an activation constant Ka = 25 microM for Tb3+. Analysis of the data reveals that the sites for Tb-FTP and Tb3+ binding are independent entities. In standard conditions these sites would be occupied by Mg-ATP and Mg2+, respectively. These findings suggest an important regulatory role of divalent cations on the activity of H+-ATPase. Replacement of H2O by D2O in the medium suggests the existence of two types of nucleotide binding sites differing by the hydration state of the Tb3+ ion in the bound Tb-FTP complex.

A single mutation confers vanadate resistance to the plasma membrane H+-ATPase from the yeast Schizosaccharomyces pombe

A single-gene nuclear mutant has been selected from the yeast Schizosaccharomyces pombe for growth resistance to Dio-9, a plasma membrane H+-ATPase inhibitor. From this mutant, called pma1, an ATPase activity has been purified. It contains a Mr = 100,000 major polypeptide which is phosphorylated by [gamma-32P] ATP. Proton pumping is not impaired since the isolated mutant ATPase is able, in reconstituted proteoliposomes, to quench the fluorescence of the delta pH probe 9-amino-6-chloro-2-methoxy acridine. The isolated mutant ATPase is sensitive to Dio-9 as well as to seven other plasma membrane H+-ATPase inhibitors. The mutant H+-ATPase activity tested in vitro is, however, insensitive to vanadate. Its Km for MgATP is modified and its ATPase specific activity is decreased. The pma1 mutation decreases the rate of extracellular acidification induced by glucose when cells are incubated at pH 4.5 under nongrowing conditions. During growth, the intracellular mutant pH is more acid than the wild type one. The derepression by ammonia starvation of methionine transport is decreased in the mutant. The growth rate of pma1 mutants is reduced in minimal medium compared to rich medium, especially when combined to an auxotrophic mutation. It is concluded that the H+-ATPase activity from yeast plasma membranes controls the intracellular pH as well as the derepression of amino acid, purine, and pyrimidine uptakes. The pma1 mutation modifies several transport properties of the cells including those responsible for the uptake of Dio-9 and other inhibitors (Ulaszewski, S., Coddington, A., and Goffeau, A. (1986) Curr. Genet. 10, 359-364).

Cutaneous mucinosis associated with multiple frozen joints and bony heterotopic deposits around the hips

A 43-year-old man suffered from migrating then additive arthralgias associated with macroscopic and microscopic cutaneous lesions compatible at first sight with reticular erythematous mucinosis. After nine months, the cutaneous picture evolved into a papular mucinosis. The patient developed "multiple frozen joints" with heterotopic bony deposits around the hips. To our knowledge, such articular problems have not yet been described in this condition. Severe systemic complications prompted the authors to treat the patient with plasma exchange and melphalan.

Decrease of the plasma membrane H+-ATPase activity during late exponential growth of Saccharomyces cerevisiae

During the last cell division of exponential growth, the H+-ATPase activity from the yeast plasma membrane decreases by a factor of two to three. This "arrest growth control" of ATPase activity is not accompanied by modification of the sensitivity to vanadate.