Nasal shedding of vaccine viruses after immunization with a Russian-backbone live attenuated influenza vaccine in India

BACKGROUND

We present post-vaccination nasal shedding findings from the phase IV, community-based, triple-blinded RCT conducted to assess efficacy of trivalent LAIV and inactivated influenza vaccines in rural north India.

METHODS

Children aged 2-10 years received LAIV or intranasal placebo across 2015 and 2016, as per initial allocation. On days 2 and 4 post-vaccination, trained study nurses collected nasal swabs from randomly selected subset of trial participants based on operational feasibility, accounting for 10.0% and 11.4% of enrolled participants in 2015 and 2016, respectively. Swabs were collected in viral transport medium and transported under cold chain to laboratory for testing by reverse transcriptase real-time polymerase chain reaction.

RESULTS

In year 1, on day 2 post-vaccination, 71.2% (74/104) of LAIV recipients shed at least one of vaccine virus strains compared to 42.3% (44/104) on day 4. During year 1, on day 2 post-vaccination, LAIV-A(H1N1)pdm09 was detected in nasal swabs of 12% LAIV recipients, LAIV-A(H3N2) in 41%, and LAIV-B in 59%. In year 2, virus shedding was substantially lower; 29.6% (32/108) of LAIV recipients shed one of the vaccine virus strains on day 2 compared to 21.3% on day 4 (23/108).

CONCLUSION

At day 2 post-vaccination in year 1, two-thirds of LAIV recipients were shedding vaccine viruses. Shedding of vaccine viruses varied between strains and was lower in year 2. More research is needed to determine the reason for lower virus shedding and vaccine efficacy for LAIV-A(H1N1)pdm09.

Revisiting live attenuated influenza vaccine efficacy among children in developing countries

Seasonal influenza epidemics cause significant pediatric mortality and morbidity worldwide. Live attenuated influenza vaccines (LAIVs) can be administered intranasally, induce a broad and robust immune response, demonstrate higher yields during manufacturing as compared to inactivated influenza vaccines (IIVs), and thereby represent an attractive possibility for young children in developing countries. We summarize recent pediatric studies evaluating LAIV efficacy in developing countries where a large proportion of the influenza-virus-associated respiratory disease burden occurs. Recently, two randomized controlled trials (RCTs) assessing Russian-backbone trivalent LAIV in children reported contradictory results; vaccine efficacy varied between Bangladesh (41 %) and Senegal (0.0 %) against all influenza viral strains. Prior to 2013, Ann Arbor-based LAIV demonstrated superior efficacy as compared to IIV. However, due to low effectiveness of the Ann Arbor-based LAIV against influenza A(H1N1)pdm09-like viruses, the CDC Advisory Committee on Immunization Practices (ACIP) recommended against the use of LAIV during the 2016-17 and 2017-18 influenza seasons. Reduced replicative fitness of the A(H1N1)pdm09 LAIV strains is thought to have led to the low effectiveness of the Ann-Arbor-based LAIV. Once the A(H1N1)pdm09 component was updated, the ACIP reintroduced the Ann-Arbor-based LAIV as a vaccine choice for the 2018-19 influenza season. In 2021, results from a 2-year RCT evaluating the Russian-backbone trivalent LAIV in rural north India reported that LAIV demonstrated significantly lower efficacy compared to IIV, but in Year 2, the vaccine efficacy for LAIV and IIV was comparable. A profounder understanding of the mechanisms underlying varied efficacy of LAIV in developing countries is warranted. Assessing replicative fitness, in addition to antigenicity, when selecting annual A(H1N1)pdm09 components in the Russian-backbone trivalent LAIVs is essential and may ultimately, enable widespread utility in resource-poor settings.

An evaluation of remote algorithm-assisted consultations for the safe prescribing of progesterone-only pills in a digital setting

Introduction

This study aimed assessed the prescribing quality of progesterone-only pills (POP) to determine whether online asynchronous algorithmic assisted consultations alone could help women or whether enhanced remote consultations still need to be performed. Our digital service follows Faculty of Sexual and Reproductive Healthcare FSRH clinical guidance, patients who have conditions that fall in category of UKMEC 3 and 4 would be signposted to other methods.1,2 The service works by patients completing an online consultation which is supported by algorithm-assisted consultations. The algorithm is written by doctors and pulls out the relevant information for the clinician to suggest whether it safe to prescribe. Asynchronized consultations using algorithms can identify patients for whom POP is not suitable to prescribe. As this is safe and scalable, it has the potential to improve access to contraception for women. For those women where technology identifies that POP is not suitable, there is still an important place for remote interaction to ensure that women are able to make an informed and safe contraceptive choice.

Aim

To review patients who met a Faculty of Sexual and Reproductive Healthcare (FSRH) exclusion for POP to determine adherence to FSRH clinical guidance on signposting these patients to in-person services where appropriate,1.2 and to review patients’ medical records, who were initially declined POP after completing an online consultation to identify the outcome and potential pathway improvement.

Methods

A retrospective case-note review of 362 patients, who met a FSRH exclusion criteria for POP, using a large digital sexual health service for POP (Cerelle, Cerazette, Norgeston, Noriday) between 1.3.21-25.5.22. Those patients who were not prescribed POP were then identified, to see how they were managed; how many were signposted to the clinic and how many were managed remotely and subsequently prescribed POP. The data underwent descriptive statistical analysis. Ethical approval was not required as this was a service evaluation.

Results

Of the 362 patients who met the FSRH exclusion criteria (100% female, aged 18-51), 288 (80%) patients were declined from POP treatment and signposted to in-persons services, 74 (20%) were prescribed POP after clinician review. Of the 288 who were initially declined POP, 110 (38%) patients sought further advice with a clinician remotely, resulting in 83 being prescribed POP and 27 being declined. Overall clinicians correctly followed guidance for 99% (284/288) of POP consultations who met the FSRH exclusion criteria.2 Of these 4 patients reported potential exclusion criteria for POP and were prescribed. Upon reflection, clinicians felt the potential exclusion criteria could have been explored further before prescribing.

Discussion/Conclusion

Asynchronous consultations bring lots of efficiencies, assists clinicians in triaging and managing the majority of patients. We’ve developed a pathway where patients can undertake a further discussion with a clinician remotely, which resulted in provision of remote contraception. This is convenient for patients and has the potential or may ease pressure off in-person services.

References

1. Faculty of Sexual & Reproductive Healthcare (FSRH). Clinical Effectiveness Unit. FSRH Guidance – Progesterone-only pills. March 2015. Amended April 2019. Royal College of Obstetricians & Gynaecologists Website www.fsrh.org/standards-and-guidance/documents/cec-ceu-guidance-pop-mar-2015 Accessed May 2022

2. Faculty of Sexual & Reproductive Healthcare (FSRH). UK Medical Eligibility Criteria (UKMEC) Summery sheets for contraceptive use. April 2016. Amended September 2019. Website www.fsrh.org/standards-and-guidance/documents/ukmec-2016-summary-sheets Accessed May 2022

Obesity related glomerulopathy in children - connecting pathophysiology to clinical care

Obesity has continued to emerge as a worldwide pandemic and has been associated with a significant rise in associated comorbidities. These include well known conditions such as hypertension and diabetes as well as lesser-known conditions such as obesity-related glomerulopathy (ORG). The main etiology of ORG is podocyte damage, but contributing theories include dysfunctional renin-angiotensin-aldosterone system (RAAS) activation, hyperinsulinemia, and lipid deposition. Recent advances have made strides in understanding the complex pathophysiology of ORG. The key to treating ORG is weight loss and proteinuria reduction. Lifestyle modification, pharmacological interventions and surgery are mainstays of management. A special focus on obese children is required as childhood obesity tracks into adulthood and primary prevention is key. In this review we discuss pathogenesis, clinical features, and established and newer treatment modalities of ORG.

Anti-factor H antibody and its role in atypical hemolytic uremic syndrome

Atypical hemolytic uremic syndrome (aHUS) an important form of a thrombotic microangiopathy (TMA) that can frequently lead to acute kidney injury (AKI). An important subset of aHUS is the anti-factor H associated aHUS. This variant of aHUS can occur due to deletion of the complement factor H genes, CFHR1 and CFHR3, along with the presence of anti-factor H antibodies. However, it is a point of interest to note that not all patients with anti-factor H associated aHUS have a CFHR1/R3 deletion. Factor-H has a vital role in the regulation of the complement system, specifically the alternate pathway. Therefore, dysregulation of the complement system can lead to inflammatory or autoimmune diseases. Patients with this disease respond well to treatment with plasma exchange therapy along with Eculizumab and immunosuppressant therapy. Anti-factor H antibody associated aHUS has a certain genetic predilection therefore there is focus on further advancements in the diagnosis and management of this disease. In this article we discuss the baseline characteristics of patients with anti-factor H associated aHUS, their triggers, various treatment modalities and future perspectives.

Runx1 negatively regulates inflammatory cytokine production by neutrophils in response to Toll-like receptor signaling

RUNX1 is frequently mutated in myeloid and lymphoid malignancies. It has been shown to negatively regulate Toll-like receptor 4 (TLR4) signaling through nuclear factor κB (NF-κB) in lung epithelial cells. Here we show that RUNX1 regulates TLR1/2 and TLR4 signaling and inflammatory cytokine production by neutrophils. Hematopoietic-specific RUNX1 loss increased the production of proinflammatory mediators, including tumor necrosis factor-α (TNF-α), by bone marrow neutrophils in response to TLR1/2 and TLR4 agonists. Hematopoietic RUNX1 loss also resulted in profound damage to the lung parenchyma following inhalation of the TLR4 ligand lipopolysaccharide (LPS). However, neutrophils with neutrophil-specific RUNX1 loss lacked the inflammatory phenotype caused by pan-hematopoietic RUNX1 loss, indicating that dysregulated TLR4 signaling is not due to loss of RUNX1 in neutrophils per se. Rather, single-cell RNA sequencing indicates the dysregulation originates in a neutrophil precursor. Enhanced inflammatory cytokine production by neutrophils following pan-hematopoietic RUNX1 loss correlated with increased degradation of the inhibitor of NF-κB signaling, and RUNX1-deficient neutrophils displayed broad transcriptional upregulation of many of the core components of the TLR4 signaling pathway. Hence, early, pan-hematopoietic RUNX1 loss de-represses an innate immune signaling transcriptional program that is maintained in terminally differentiated neutrophils, resulting in their hyperinflammatory state. We hypothesize that inflammatory cytokine production by neutrophils may contribute to leukemia associated with inherited RUNX1 mutations.

Economic impact and cost-effectiveness of fracture liaison services: a systematic review of the literature

Fracture liaison services (FLS), implemented in different ways and countries, are reported to be a cost-effective or even a cost-saving secondary fracture prevention strategy. This presumed favorable cost-benefit relationship is encouraging and lends support to expanded implementation of FLS per International Osteoporosis Foundation Best Practice Standards. This study summarizes the economic impact and cost-effectiveness of FLS implemented to reduce subsequent fractures in individuals with osteoporosis. This systematic review identified studies reporting economic outcomes for FLS in osteoporotic patients aged 50 and older through a comprehensive search of MEDLINE, EMBASE, Cochrane Central, and PubMed of studies published January, 2000 to December, 2016. Grey literature (e.g., Google scholar, conference abstracts/posters) were also hand searched through February 2017. Two independent reviewers screened titles and abstracts and conducted full-text review on qualified articles. All disagreements were resolved by discussion between reviewers to reach consensus or by a third reviewer. In total, 23 qualified studies that evaluated the economic aspects of FLS were included: 16 cost-effectiveness studies, 2 cost-benefit analyses, and 5 studies of cost savings. Patient populations varied (prior fragility fracture, non-vertebral fracture, hip fracture, wrist fracture), and FLS strategies ranged from mail-based interventions to comprehensive nurse/physician-coordinated programs. Cost-effectiveness studies were conducted in Canada, Australia, USA, UK, Japan, Taiwan, and Sweden. FLS was cost-effective in comparisons with usual care or no treatment, regardless of the program intensity or the country in which the FLS was implemented (cost/QALY from $3023-$28,800 US dollars (USD) in Japan to $14,513-$112,877 USD in USA. Several studies documented cost savings. FLS, implemented in different ways and countries, are reported to be cost-effective or even cost-saving. This presumed favorable cost-benefit relationship is encouraging and lends support to expanded implementation of FLS per International Osteoporosis Foundation Best Practice Standards.

Identifying characteristics of an effective fracture liaison service: systematic literature review

Fracture liaison services (FLS) have been demonstrated to improve outcomes following osteoporotic fracture. The aim of this systematic literature review (SLR) was to determine the characteristics of an FLS that lead to improved patient outcomes. We conducted a SLR, including articles published between 2000 and February 2017, using global (Medline, EMBASE, PubMed and Cochrane Library) and local databases. Studies including patients aged ≥ 50 years with osteoporotic fractures enrolled in an FLS were assessed. Information extracted from each article included key person coordinating the FLS (physician, nurse or other healthcare professional), setting (hospital vs community), intensity (single vs multiple), duration (long vs short term), fracture type and gender. A meta-analysis of randomised controlled trials was conducted based on the key person coordinating the FLS. Out of 7236 articles, 57 were considered to be high quality and identified for further analysis. The SLR identified several components which contributed to FLS success, including multidisciplinary involvement, driven by a dedicated case manager, regular assessment and follow-up, multifaceted interventions and patient education. Meta-analytic data confirm the effectiveness of an FLS following an osteoporotic fracture: approximate 27% increase in the likelihood of BMD testing and up to 21% increase in the likelihood of treatment initiation compared with usual care. The balance of evidence indicates that the multifaceted FLS and dedicated coordination are important success factors that contribute to effective FLS interventions which reduce fracture-related morbidity and mortality.

Fracture liaison services for osteoporosis in the Asia-Pacific region: current unmet needs and systematic literature review

The analysis aimed to identify the treatment gaps in current fracture liaison services (FLS) and to provide recommendations for best practice establishment of future FLS across the Asia-Pacific region. The findings emphasize the unmet need for the implementation of new programs and provide recommendations for the refinement of existing ones. The study's objectives were to evaluate fracture liaison service (FLS) programs in the Asia-Pacific region and provide recommendations for establishment of future FLS programs. A systematic literature review (SLR) of Medline, PubMed, EMBASE, and Cochrane Library (2000-2017 inclusive) was performed using the following keywords: osteoporosis, fractures, liaison, and service. Inclusion criteria included the following: patients ≥ 50 years with osteoporosis-related fractures; randomized controlled trials or observational studies with control groups (prospective or retrospective), pre-post, cross-sectional and economic evaluation studies. Success of direct or indirect interventions was assessed based on patients' understanding of risk, bone mineral density assessment, calcium intake, osteoporosis treatment, re-fracture rates, adherence, and mortality, in addition to cost-effectiveness. Overall, 5663 unique citations were identified and the SLR identified 159 publications, reporting 37 studies in Asia-Pacific. These studies revealed the unmet need for public health education, adequate funding, and staff resourcing, along with greater cooperation between departments and physicians. These actions can help to overcome therapeutic inertia with sufficient follow-up to ensure adherence to recommendations and compliance with treatment. The findings also emphasize the importance of primary care physicians continuing to prescribe treatment and ensure service remains convenient. These findings highlight the limited evidence supporting FLS across the Asia-Pacific region, emphasizing the unmet need for new programs and/or refinement of existing ones to improve outcomes. With the continued increase in burden of fractures in Asia-Pacific, establishment of new FLS and assessment of existing services are warranted to determine the impact of FLS for healthcare professionals, patients, family/caregivers, and society.

Risk factor profiling and study of atherosclerotic coronary plaque burden and morphology with coronary computed tomography angiography in coronary artery disease among young Indians

BACKGROUND

With a decade earlier manifestation of coronary artery disease (CAD) and paucity of data characterizing coronary plaque with coronary computed tomography angiography (CTA) among CAD patients in India, the study aimed to analyze patient characteristics and coronary plaque burden and morphology in young Indian patients with CAD.

METHODS

Serial coronary CTA was performed in 96 CAD patients. Among 60 patients ≤40years, risk factor and coronary plaque analysis done using a 256- slice CT in 33 patients with acute coronary syndrome (ACS) was compared with 27 patients with chronic stable angina (CSA). Univariate and multivariate analysis was performed, for factors predicting ACS as an outcome among young CAD patients. In addition, quantitative and morphologic plaque characteristics were compared among those ≤40years and >40years.

RESULTS

Among 60 subjects ≤40years of age, 77% had dyslipidemia, 70% high lipoprotein(a), 53.33% elevated hs-CRP and 73.33% raised homocysteine. hs-CRP (9.33 vs. 3.33, p value=0.01) and serum triglycerides (178.67 vs. 141.42, p value=0.03) were markedly raised in patients with ACS. Statistically significant number of patients in the ACS group had positive remodelling (ACS, 69.7% vs. CSA, 14.8%; p value<0.001), low attenuation plaque (ACS, 63.6% vs. CSA, 11.1%; p value<0.001), spotty calcification (ACS, 36.4% vs. CSA, 3.7%; p=0.002) and non-calcified plaque (ACS, 69.7% vs. CSA, 11.1%; p<0.001). On multivariate analysis, only lipoprotein (a) >30mg/dL and composite vulnerability score maintained a predictive value for ACS in patients ≤40years. Statistically significant number of patients in the younger age group had higher mean total plaque volume (66.17±41.31mm³ vs. 44.94±49.07mm³; p=0.03), remodelling index (1.5±0.27 vs. 1.08±0.38; p=0.0001). Comparing culprit lesion characteristics of ACS patients in the two age groups, positive remodelling (95.8% vs. 70.5%, p=0.02), spotty calcification (50% vs. 11.7%, p=0.01) and non-calcified plaque (95.8% vs. 70.5%, p=0.02) were significantly more frequent in patients ≤40years.

CONCLUSION

ACS in young Indians is characterized by a higher prevalence of both conventional and newer risk factors. In addition, culprit lesions in young ACS patients are more frequently characterized by coronary plaques with high risk morphological features. This may have implications in terms of preventive strategies to identify this high-risk group.

Hepatitis B virus molecular biology and pathogenesis

As obligate intracellular parasites, viruses need a host cell to provide a milieu favorable to viral replication. Consequently, viruses often adopt mechanisms to subvert host cellular signaling processes. While beneficial for the viral replication cycle, virus-induced deregulation of host cellular signaling processes can be detrimental to host cell physiology and can lead to virus-associated pathogenesis, including, for oncogenic viruses, cell transformation and cancer progression. Included among these oncogenic viruses is the hepatitis B virus (HBV). Despite the availability of an HBV vaccine, 350-500 million people worldwide are chronically infected with HBV, and a significant number of these chronically infected individuals will develop hepatocellular carcinoma (HCC). Epidemiological studies indicate that chronic infection with HBV is the leading risk factor for the development of HCC. Globally, HCC is the second highest cause of cancer-associated deaths, underscoring the need for understanding mechanisms that regulate HBV replication and the development of HBV-associated HCC. HBV is the prototype member of the Hepadnaviridae family; members of this family of viruses have a narrow host range and predominately infect hepatocytes in their respective hosts. The extremely small and compact hepadnaviral genome, the unique arrangement of open reading frames, and a replication strategy utilizing reverse transcription of an RNA intermediate to generate the DNA genome are distinguishing features of the Hepadnaviridae. In this review, we provide a comprehensive description of HBV biology, summarize the model systems used for studying HBV infections, and highlight potential mechanisms that link a chronic HBV-infection to the development of HCC. For example, the HBV X protein (HBx), a key regulatory HBV protein that is important for HBV replication, is thought to play a cofactor role in the development of HBV-induced HCC, and we highlight the functions of HBx that may contribute to the development of HBV-associated HCC.

[Dental fluorosis: an epidemiological investigation in the area of Ouardanine in Tunisia]

In this work, we carried out a transverse epidemiological investigation about the oral health state of pupils in the Ouardanine area. The investigation concerned 300 fifteen-year-old pupils. An amount of fluoride was administrated within drinking water. Further studies, within few years, will be desirableto follow the fluorosis evolution in this area.

Dentin alteration of deciduous teeth in human hypophosphatemic rickets

Familial hypophosphatemic rickets is in most cases transmitted as an X-linked dominant trait and results from mutation of the PHEX gene, predominantly expressed in osteoblast and odontoblast. Patients have been reported to display important dentin defects, and therefore, we explored the dentin structure, composition, and distribution of extracellular matrix (ECM) molecules in hypophosphatemic human deciduous teeth. Compared to age-matched controls, the dentin from hypophosphatemic patients exhibited major differences: presence of large interglobular spaces resulting from the lack of fusion of calcospherites in the circumpulpal dentin; defective mineralization in the interglobular spaces contrasting with normal Ca-P levels in the calcospherites on X-ray microanalysis; abnormal presence of low-molecular weight protein complexes recognized on Western blots by antibodies against matrix extracellular phosphoglycoprotein (MEPE), dentin sialoprotein, osteopontin, and reduced osteocalcin (OC) level; and accumulation in the interglobular spaces of immunolabeling with antibodies against DSP, dentin matrix protein, bone sialoprotein, MEPE and OC, while chondroitin/dermatan sulfate glycosaminoglycans were exclusively located inside calcospherites. Alterations of the post-translational processing or partial degradation of some ECM appear as key factors in the formation of the defective hypophosphatemic dentin.

Down regulation of humoral immunity in chickens due to carbendazim

This study was planned to investigate the effect of very low dose of carbendazim on the humoral immune response in the chicken. Sixteen adult chickens, earlier vaccinated against New Castle Disease were divided in two experimental groups. Chickens of group I served as control, while group II birds were given a feed containing 200 ppm of carbendazim, which is considered no observable effect level (NOEL) dose, for a period of 6 months. The Humoral immune response was measured by the B-lymphocyte blastogenesis assay using lipopolysaccharide as mitogen and the quantitation of IgG, IgA, IgM levels by using respective antichicken conjugates, through an ELISA method. Total serum proteins, serum gamma-globulins and globulins were measured using commercially available kits. Carbendazim significantly (P< or =0.05) reduced both the B-lymphocyte proliferation and serum IgG, IgM and IgA levels, leading to decreased immunocompetence. At the end of experiment percent decrease in B-lymphocyte proliferation was 20.5% and that in serum IgG, IgM and IgA were 11.2, 22.9 and 28.8%, respectively. The percent decrease in total serum protein, serum gamma-globulins and serum globulins were 14.6, 18.5 and 9.7%, respectively. Results clearly indicated down regulation of humoral immunity by carbendazim at NOEL dose.

Mechanism of specific target recognition and RNA hydrolysis by ribonucleolytic toxin restrictocin

Restrictocin, a member of the fungal ribotoxin family, specifically cleaves a single phosphodiester bond in the 28S rRNA and potently inhibits eukaryotic protein synthesis. Residues Tyr47, His49, Glu95, Phe96, Pro97, Arg120, and His136 have been predicted to form the active site of restrictocin. In this study, we have individually mutated these amino acids to alanine to probe their role in restrictocin structure and function. The role of Tyr47, His49, Arg120, and His136 was further investigated by making additional mutants. Mutating Arg120 or His136 to alanine or the other amino acids rendered the toxin completely inactive, whereas mutating Glu95 to alanine only partially inactivated the toxin. Mutation of Phe96 and Pro97 to Ala had no effect on the activity of restrictocin. The Tyr47 to alanine mutant was inactive in inhibiting protein synthesis, and had a nonspecific ribonuclease activity on 28S rRNA similar to that shown previously for the His49 to Ala mutant. Unlike the His136 to Ala mutant, the double mutants containing Tyr47 or His49 mutated to alanine along with His136 did not compete with restrictocin to cause a significant reduction in the extent of cleavage of 28S rRNA. In a model of restrictocin and a 29-mer RNA substrate complex, residues Tyr47, His49, Glu95, Arg120, and His136 were found to be near the cleavage site on RNA. It is proposed that in restrictocin Glu95 and His136 are directly involved in catalysis, Arg120 is involved in the stabilization of the enzyme-substrate complex, Tyr47 provides structural stability to the active site, and His49 determines the substrate specificity.

Down-regulation of specific members of the glutamine synthetase gene family in alfalfa by antisense RNA technology

Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of NH3 with glutamate to produce glutamine. In plants GS is an octameric enzyme and is located either in the cytoplasm (GS1) or in the chloroplast (GS2). Two distinct classes of GS1 genes with unique 3'-untranslated region (3'UTR) have been identified in alfalfa. We have demonstrated that the two classes exhibit differential expression pattern in the different plant organs suggesting different functional roles for the different isozymes. To determine the functional significance of the two classes of GS1 genes in alfalfa, we have utilized antisense gene constructs aimed specifically at the 3'UTR of the two GS1 genes and introduced them individually into alfalfa. Our data show that the gene constructs are effective in lowering the corresponding transcript level very effectively though there were organ-specific differences in the level of reduction. No transcript corresponding to the antisense gene construct was detected in any of the alfalfa transformants though they accumulated to significant levels in transgenic tobacco containing the same construct. This suggests that the antisense transcript was not stable in the presence of the homologous target sequence. Transgenic alfalfa with up to 80% reduction in the transcript level corresponding to each gene class, however, showed no reduction in GS activity or GS1 polypeptide level. The results suggest that GS1 mRNA levels are not rate-limiting for GS1 polypeptide synthesis and that GS levels are controlled both at the transcriptional and translational/post-translational level.

Coexpression of the maize delta-zein and beta-zein genes results in stable accumulation of delta-zein in endoplasmic reticulum-derived protein bodies formed by beta-zein

Zeins, the major seed storage proteins of maize, are of four distinct types: alpha, beta, delta, and gamma. They are synthesized on the rough endoplasmic reticulum (ER) in a sequential manner and deposited in ER-derived protein bodies. We investigated the potential for producing sulfur-rich beta-zein and delta-zein proteins in leaf and seed tissues by expressing the corresponding genes in a constitutive manner in transgenic tobacco. The delta-zein and beta-zein, when synthesized individually, were stable in the vegetative tissues and were deposited in unique, zein-specific ER-derived protein bodies. Coexpression of delta-zein and beta-zein genes, however, showed that delta-zein was colocalized in beta-zein-containing protein bodies and that the level of delta-zein was fivefold higher in delta-/beta-zein plants than in delta-zein plants. We conclude that delta-zein interacts with beta-zein and that the interaction has a stabilizing effect on delta-zein.

Putrescine Aminopropyltransferase Is Responsible for Biosynthesis of Spermidine, Spermine, and Multiple Uncommon Polyamines in Osmotic Stress-Tolerant Alfalfa

The biosynthesis of polyamines from the diamine putrescine is not fully understood in higher plants. A putrescine aminopropyltransferase (PAPT) enzyme activity was characterized in alfalfa (Medicago sativa L.). This enzyme activity was highly specific for putrescine as the initial substrate and did not recognize another common diamine, 1,3-diaminopropane, or higher-molecular-weight polyamines such as spermidine and spermine as alternative initial substrates. The enzyme activity was inhibited by a general inhibitor of aminopropyltransferases, 5[prime]-methylthioadenosine, and by a specific inhibitor of PAPTs, cyclohexylammonium sulfate. The initial substrate specificity and inhibition characteristics of the enzyme activity suggested that it is a classical example of a PAPT. However, this enzyme activity yielded multiple polyamine products, which is uncharacteristic of PAPTs. The major reaction product of PAPT activity in alfalfa was spermidine. The next most abundant products of the enzyme reaction using putrescine as the initial substrate included the tetramines spermine and thermospermine. These two tetramines were distinguished by thin-layer chromatography to be distinct reaction products exhibiting differential rates of formation. In addition, the uncommon polyamines homocaldopentamine and homocaldohexamine were tentatively identified as minor enzymatic reaction products but only in extracts prepared from osmotic stresstolerant alfalfa cultivars. PAPT activity from alfalfa was highest in meristematic shoot tip and floral bud tissues and was not detected in older, nonmeristematic tissues. Product inhibition of the enzyme activity was observed after spermidine was added into the in vitro assay for alfalfa PAPT activity. A biosynthetic pathway is proposed that accounts for the characteristics of this PAPT activity and accommodates a novel scheme by which certain uncommon polyamines are produced in plants.

Scintigraphic detection of a disseminated synovial lymphoma in a postrenal transplant patient

Post-transplant lymphoproliferative disease is a recognized complication of immunosuppressive therapy, however, articular lymphomas involving the synovlum are very rare. Disseminated synovial lymphoma of the knee with hepatic involvement in a patient after renal transplant was suggested on bone/gallium scintigraphy and confirmed by synovial biopsy. Gallium scanning thus was instrumental in the evaluation, staging, and proper treatment of this rare condition.

Scintigraphic localization of recurrent anastomotic site bleeding in the gastrointestinal tract

Scanning with Tc-99m labeled RBC was performed in two patients with recurrent postoperative gastrointestinal bleeding after partial colonic resection. Imaging correctly identified the source of bleeding at the anastomotic site in the large bowel, effectively contributing in the patient's treatment planning. Radionuclide scintigraphy provides a simple, noninvasive modality to diagnose and manage difficult clinical situations such as postoperative bleeding.

Accumulation of 15-Kilodalton Zein in Novel Protein Bodies in Transgenic Tobacco

Zeins, the seed storage proteins of maize, are a group of alcohol-soluble polypeptides of different molecular masses that share a similar amino acid composition but vary in their sulfur amino acid composition. They are synthesized on the rough endoplasmic reticulum (ER) in the endosperm and are stored in ER-derived protein bodies. Our goal is to balance the amino acid composition of the methionine-deficient forage legumes by expressing the sulfur amino acid-rich 15-kD zeins in their leaves. However, it is crucial to know whether this protein would be stable in nonseed tissues of transgenic plants. The major focus of this paper is to compare the accumulation pattern of the 15-kD zein protein with a vacuolar targeted seed protein, [beta]-phaseolin, in nonseed tissues and to determine the basis for its stability/instability. We have introduced the 15-kD zein and bean [beta]-phaseolin-coding sequences behind the 35S cauliflower mosaic virus promoter into tobacco (Nicotiana tabacum) and analyzed the protein's accumulation pattern in different tissues. Our results demonstrate that the 15-kD seed protein is stable not only in seeds but in all nonseed tissues tested, whereas the [beta]-phaseolin protein accumulated only in mid- and postmaturation seeds. Interestingly, zein accumulates in novel protein bodies both in the seeds and in nonseed tissues. We attribute the instability of the [beta]-phaseolin protein in nonseed tissues to the fact that it is targeted to protease-rich vacuoles. The stability of the 15-kD zein could be attributed to its retention in the ER or to the protease-resistant nature of the protein.

Evidence for the occurrence of polyamine oxidase in the dicotyledonous plant Medicago sativa L. (alfalfa)

Polyamine oxidase (EC 1.5.3.3) activity has not been detected previously in cells of dicotyledonous plants, although it has been characterized extensively in monocotyledonous plants. Evidence is presented in this report for the occurrence of polyamine oxidase in dialyzed crude extracts of the dicotyledonous plant, Medicago sativa L. (alfalfa). Three enzyme assays were used to quantitate the formation of the three products of the reaction catalyzed by polyamine oxidase. 1-Pyrroline formation was measured colorimetrically as a yellow quinazolinium complex with o-aminobenzaldehyde. Hydrogen peroxide formation was measured spectrophotometrically with a coupled peroxidase assay system by peroxidative oxidation of guaiacol. [(3)H]1,3-Diaminopropane formation was measured by using [1,8-(3)H]spermidine as the substrate and separating the radiolabelled reaction product from the substrate by paper electrophoresis. This latter assay provided evidence that a polyamine oxidase of type [EC 1.5.3.3] catalyzed the cleavage reaction between a secondary nitrogen atom and an adjacent carbon of the butyl moiety of spermidine. Significant polyamine oxidase activity was detected in floral tissues, cortex tissues of the root, young leaves, and young germinated seedlings of alfalfa. The occurrence of polyamine oxidase in alfalfa accounts for the formation of the essential substrate, 1,3-diaminopropane, required for the biosynthesis of the uncommon polyamines, norspermidine and norspermine, which we have recently detected in alfalfa.

Novel occurrence of uncommon polyamines in higher plants

Diamines and polyamines are ubiquitous components of living cells, and apparently are involved in numerous cellular and physiological processes. Certain "uncommon" polyamines have limited distribution in nature and have been associated primarily with organisms adapted to extreme environments, although the precise function of these polyamines in such organisms is unknown. This article summarizes current knowledge regarding the occurrence in higher plants of the uncommon polyamines related to and including norspermidine and norspermine. A putative biosynthetic pathway to account for the occurrences of these uncommon polyamines in higher plants is presented, with a summary of the supporting evidence indicating the existence of the requisite enzymatic activities in alfalfa, Medicago sativa L.

In vitro regeneration of plants from hypocotyl segments of Amaranthus paniculatus

Hypocotyl segments, 5 to 8 mm length from 4 to 7 day old seedlings, callused on B5 medium supplemented with Kn (0.5 ppm) and NAA (0.1 ppm). Even without transfer, shoots were formed in such cultures. About 20% of the cultures produced multiple shoots. In medium with 1 ppm each of Kn and NAA direct shoots were formed at one end of the hypocotyl segment and callusing was initiated at the other end. The plants obtained in either medium formed roots and could be transferred to soil for further growth.

Induction and differentiation of callus from embryos of Cocos nucifera L. by IAA-conjugates

Calli from young embryos of Cocos nucifera L. were induced on B5 medium supplemented with IAA-conjugates (IAA-asp or IAA-ala) at a concentration of 2.0 mg/1 and callusing was increased by about 10% if both IAA-conjugates, IAA-asp and IAA-ala were added together. Differentiation of shoots and roots was achieved by transferring calli to B5 medium supplemented with either IAA-asp (2.0 mg/1)+Kn(2.0 mg/1) or NAA (2.0 mg/1). Complete plantlets were obtained on B5 medium supplemented with NAA (0.5 mg/1)+BAP (2.0 mg/1)+PVP (1.0 g/1).