Thrombosis with thrombocytopenia syndrome: A database review of clinical trial and post-marketing experience with Ad26.COV2.S

BACKGROUND

Thrombosis with thrombocytopenia syndrome (TTS) is a very rare disorder described after vaccination with adenoviral vector-based COVID-19 vaccines. Co-occurring thrombosis with thrombocytopenia reported after vaccination can be a proxy for identification of TTS.

METHODS

Descriptive database review of all cases of co-occurring (within 42 days) thrombosis with thrombocytopenia in participants in Ad26.COV2.S clinical trials or recipients of Ad26.COV2.S in real-world clinical practice. Cases were retrieved from Janssens' clinical trial and Global Medical Safety databases.

RESULTS

There were 34 cases of co-occurring thrombosis with thrombocytopenia in Ad26.COV2.S recipients (46 per 100,000 person-years) and 15 after placebo (75 per 100,000 person-years) in clinical trials. Among Ad26.COV2.S recipients, mean age at the time of the event was 63 years (range 25-85), 82 % were male, mean time-to-onset 112 days (range 8-339) post-last Ad26.COV2.S dose, 26 events occurred post-dose-1, and 7 within a 28-day risk window post-vaccination. Diagnostic certainty was evaluated using Brighton Collaboration, US Centers for Disease Control and Prevention, and European Medicines Agency Pharmacovigilance Risk Assessment Committee case definitions. One case met the highest level of diagnostic certainty for all 3 definitions. There were 355 spontaneous reports of co-occurring thrombosis with thrombocytopenia in the Global Medical Safety database, 47 % males, 85 % within 28-days after vaccination. Twenty-seven cases met the highest level of diagnostic certainty for all definitions, 21 female, 19 with cerebral venous sinus thrombosis, age-range 18-68 years. Time-to-onset was 7-14 days post-vaccination in 20 cases. There were 8 fatalities.

CONCLUSION

TTS induced by Ad26.COV2.S is very rare. Most co-occurring thrombosis with thrombocytopenia does not constitute TTS.

Immunological non-inferiority and safety of a quadrivalent inactivated influenza vaccine versus two trivalent inactivated influenza vaccines in China: Results from two studies

WHO UNIVERSAL TRIAL NUMBERS (UTNS)

U1111-1174-4615 and U1111-1174-4698.

CLINICALTRIALS.GOV

NCT04210349 and NCT03430089.

Enhanced passive safety surveillance of a quadrivalent inactivated split virion influenza vaccine in Finland during the influenza season 2020/21

BACKGROUND

The European Medicines Agency (EMA) requires enhanced safety surveillance to be conducted for annual seasonal influenza vaccines with the aim of rapidly detecting any potential new safety concerns before the peak immunisation period of the vaccine in any given year. The aim of this study was to detect any clinically significant change in the frequency or severity of expected reactogenicity of the quadrivalent inactivated split-virion influenza vaccine (IIV4) during routine immunisation in Finland for the 2020/21 season. The primary objective was to investigate the frequency of suspected adverse drug reactions (ADRs) occurring within 7 days following vaccination.

METHODS

Enhanced passive safety surveillance of individuals vaccinated with IIV4 was conducted from October 9, 2020 to November 30, 2020 across seven sites in Finland. The vaccinee reporting rate and ADR reporting rate were calculated and compared with known or expected safety data in order to identify any clinically significant changes.

RESULTS

Data were collected from 1008 individuals with 29 vaccinees reporting 82 suspected ADRs. Of these, 28 people reported 79 suspected ADRs within 7 days following vaccination, corresponding to a vaccinee reporting rate of 2.78% (95% CI: 1.85, 3.99) (ADR reporting rate, 7.84% [95% CI: 6.25, 9.67%]). The most frequently reported ADRs were injection site reactions (vaccination site pain, vaccination site erythema and vaccination site swelling) (n = 46, 2.28%), myalgia (n = 9, 0.89%) and headache (n = 8, 0.79%). No serious suspected adverse events were reported at any point post-vaccination and ADR reporting rates were in general lower compared to those reported for IIV4 in the 2019/20 surveillance study.

CONCLUSION

No clinically significant changes in what is known or expected for IIV4 were reported for the 2020/21 season which supports the safety profile of this vaccine and will help maintain public confidence in influenza vaccination.

Copper cobalt tin sulphide (Cu2CoSnS4) anodes synthesised using a chemical route for stable and efficient rechargeable lithium-ion batteries

In everyday life superior lithium-ion batteries (LIB) with fast charging ability have become a valuable asset. The LIB performance of anode composite copper cobalt tin sulphide (Cu2CoSnS4; CCTS) electrodes, which...

Impact of regular physical activity awareness sessions by primary care physicians in rural India

Funding Acknowledgements

Type of funding sources: None.

Background

Regular physical activity is associated with improved physical and mental health. Studies have shown that regular physical activity reduces the risk of cardiovascular diseases, diabetes mellitus, osteoporosis, depression and obesity. Patients frequently identify their family physicians as an important source of constant encouragement for physical activity.

Purpose

We wanted to assess the impact of regular awareness sessions about physical activity by Primary care physicians in adults. 

Methods

73 participants between the age group 30 to 60 years were recruited in this single center study in rural India.70 participants completed this 6 month intervention study whereas 3 participants dropped out of study. Once in a month audio visual awareness session of one hour were conducted from August 2017 to January 2018 by primary care physicians to educate the participants about ill effects of sedentary lifestyle and benefits of regular physical activity. Pre and post intervention data were collected by using validated Godin leisure time exercise questionnaire from all 70 participants. Paired t test and Wilcoxon test were used to compare pre- and post-intervention data. Percentage increase in physical activity score was also calculated.

Results

In this study baseline Godin score pre intervention were 38.82 ± 12.22 (Mean ± SD) and post intervention were 65.98 ± 11.25 (Mean ± SD). Participants significantly improved Godin score post intervention which were statistically significant (p: < 0.001) . Compared to baseline pre intervention score, there was 170% increase in physical activity score post intervention.

Conclusions

Results of this intervention suggest that regular awareness sessions using modern technology is cost effective in changing physical activity behavior in people. Active involvement of primary care physician in this intervention will further help in establishing and continuing physical activity behavior. Physicians can play a major role in promotion of physical activity. As primary care physicians have direct regular contact with their patients and their families, their role in promotion of physical activity will have more impact and long-lasting effect on patient’s behavior. We assume that similar studies are needed to promote physical activity in the people.

P6378Characteristics of hypertensive iron ore miners with oral glucocorticoid induced diabetes mellitus and compromised lung function

Introduction

Oral glucocorticoids are efficacious agents for treating respiratory diseases, with high risk to induce metabolic diseases including diabetes and hypertension

Purpose

To analyse the hypertensive patient population from the rural setting on ongoing glucocorticoid treatment and diagnosed as diabetic due to the extensive chronic methylprednisolone equivalent glucocorticoid dose of more than 4 mg/day for at least 3 months for treatment of respiratory ailments due to occupational hazard

Methods

We diagnosed the identified and analysed a subset of patients from the Redi iron ore miners (n=25,500), who were newly diagnosed diabetics (n=1100) and with associated systemic hypertension (systolic BP >140 mmHg, diastolic BP > than 90 mmHg). Patients diagnosed as Oral Glucocorticoid Induced Diabetes Mellitus (GIDM) and hypertensives (n=847; 572 males and 275 females) were characterised on metabolic parameters. t-test was utilised for statistical analysis

Results

We observed a high incidence of GIDM (4.31%) with a high rate of hypertension (77%, 847/1100). Mean SBP was 150 mmHg (SD ± 9.9, 95% CI 147–152), mean DBP was 90 mmHg (SD ± 8.9, 95% CI 88–92). BMI in GIDM with hypertension (GIDM-H) group was similar to GIDM group (26 kg/m2) (Table), with relatively older age in GIDM–H (53 vs 51 years). The glycemic parameters were relatively more deranged in GIDM-H group. There was significant correlation for a high propensity of relatively younger <50 years (n=506) and near normal weight people with BMI <26 kg/m2 (n=594) to develop GIDM (p=0.006)

Metabolic Parameters GIDM Vs GIDM-H Mean ±SD, min, max, 95% CI GIDM (n=1100) GIDM with Hypertension (n=847) Age (yrs) 51 (SD ±14, 95% CI 48–54) 53 (SD ±13, 95% CI 50–56) HbA1c (%) 7.1 (SD ±0.62, 95% CI 7–7.3), 7.2 (SD ±0.60, 95% CI 7.1–7.3) BMI (kg/m2) 26 (SD ±3.6, 95% CI 25–27) 26 (SD ±3.4, 95% CI 25–27) Fasting Plasma Glucose (mg/dl) 146 (SD ±49, 95% CI 136–155) 149 (SD ±48, 95% CI 138–160) Post Prandial Glucose (mg/dl) 207 (SD ±74, 95% CI 192 - 221) 212 (SD ±74, 95% CI 195–228)

Conclusions

The high rates of hypertension in patients with GIDM is an alarmingly problem which has pronounced harmful comorbid implications, especially in younger, economically productive population in limited resource setting. The health care professionals need to be educated to limit use of glucocorticoids to inhalational therapy with minimal systemic effects. Specific pathophysiological approach to address the steroid induced insulin resistance, strategies to reduce cardiovascular risk and damage, makes treatment of hypertension and GIDM difficult, which calls for action to limit the mining activities and mitigate risk of chronic complications

Land resource management of coastal areas in Indian cities: comparative assessment with prevailing methods

Indian coastal cities, enriched with a variety of marine resources, are a major driver of economic growth where the Indian coast provides shelter to a large part (∼49%) of the total population in India. Proper planning of coastal resources is crucial for sustainable development, which can be achieved through advanced planning methods. Current methods for the planning of coastal landscapes in Indian coastal cities are ineffective in sustainable utilization of coastal resources and need improvements. This paper evaluates the application of the new planning method for classification of coastal landscapes in Mumbai city. The new method incorporates geospatial technology and multicriteria decision-making approach. The existing method of coastal area classification is based on Coastal Regulation Zone (CRZ) notifications by the central government, which has ambiguities in implementation. In the new method, coastal areas of Mumbai city are classified based on the physical eligibility of the coast for management of coastal resources and spatially compared with prevailing unscientific classification of coastal areas. The most dense urban area is considered for quantitative comparison of prevailing and new classification approach. Results of coastal area classifications by both methods disclosed the significant differences among different classes of coastal land. The results are validated with field visits and ground truthing along the coast of Mumbai. The findings of this study will enable the stakeholders to utilize available coastal land resources in an efficient manner for developmental and conservational activities at regional and neighborhood scale.

Fungal Planet description sheets: 868-950

Novel species of fungi described in this study include those from various countries as follows: Australia, Chaetomella pseudocircinoseta and Coniella pseudodiospyri on Eucalyptus microcorys leaves, Cladophialophora eucalypti, Teratosphaeria dunnii and Vermiculariopsiella dunnii on Eucalyptus dunnii leaves, Cylindrium grande and Hypsotheca eucalyptorum on Eucalyptus grandis leaves, Elsinoe salignae on Eucalyptus saligna leaves, Marasmius lebeliae on litter of regenerating subtropical rainforest, Phialoseptomonium eucalypti (incl. Phialoseptomonium gen. nov.) on Eucalyptus grandis × camaldulensis leaves, Phlogicylindrium pawpawense on Eucalyptus tereticornis leaves, Phyllosticta longicauda as an endophyte from healthy Eustrephus latifolius leaves, Pseudosydowia eucalyptorum on Eucalyptus sp. leaves, Saitozyma wallum on Banksia aemula leaves, Teratosphaeria henryi on Corymbia henryi leaves. Brazil, Aspergillus bezerrae, Backusella azygospora, Mariannaea terricola and Talaromyces pernambucoensis from soil, Calonectria matogrossensis on Eucalyptus urophylla leaves, Calvatia brasiliensis on soil, Carcinomyces nordestinensis on Bromelia antiacantha leaves, Dendryphiella stromaticola on small branches of an unidentified plant, Nigrospora brasiliensis on Nopalea cochenillifera leaves, Penicillium alagoense as a leaf endophyte on a Miconia sp., Podosordaria nigrobrunnea on dung, Spegazzinia bromeliacearum as a leaf endophyte on Tilandsia catimbauensis, Xylobolus brasiliensis on decaying wood. Bulgaria, Kazachstania molopis from the gut of the beetle Molops piceus. Croatia, Mollisia endocrystallina from a fallen decorticated Picea abies tree trunk. Ecuador, Hygrocybe rodomaculata on soil. Hungary, Alfoldia vorosii (incl. Alfoldia gen. nov.) from Juniperus communis roots, Kiskunsagia ubrizsyi (incl. Kiskunsagia gen. nov.) from Fumana procumbens roots. India, Aureobasidium tremulum as laboratory contaminant, Leucosporidium himalayensis and Naganishia indica from windblown dust on glaciers. Italy, Neodevriesia cycadicola on Cycas sp. leaves, Pseudocercospora pseudomyrticola on Myrtus communis leaves, Ramularia pistaciae on Pistacia lentiscus leaves, Neognomoniopsis quercina (incl. Neognomoniopsis gen. nov.) on Quercus ilex leaves. Japan, Diaporthe fructicola on Passiflora edulis × P. edulis f. flavicarpa fruit, Entoloma nipponicum on leaf litter in a mixed Cryptomeria japonica and Acer spp. forest. Macedonia, Astraeus macedonicus on soil. Malaysia, Fusicladium eucalyptigenum on Eucalyptus sp. twigs, Neoacrodontiella eucalypti (incl. Neoacrodontiella gen. nov.) on Eucalyptus urophylla leaves. Mozambique, Meliola gorongosensis on dead Philenoptera violacea leaflets. Nepal, Coniochaeta dendrobiicola from Dendriobium lognicornu roots. New Zealand, Neodevriesia sexualis and Thozetella neonivea on Archontophoenix cunninghamiana leaves. Norway, Calophoma sandfjordenica from a piece of board on a rocky shoreline, Clavaria parvispora on soil, Didymella finnmarkica from a piece of Pinus sylvestris driftwood. Poland, Sugiyamaella trypani from soil. Portugal, Colletotrichum feijoicola from Acca sellowiana. Russia, Crepidotus tobolensis on Populus tremula debris, Entoloma ekaterinae, Entoloma erhardii and Suillus gastroflavus on soil, Nakazawaea ambrosiae from the galleries of Ips typographus under the bark of Picea abies. Slovenia, Pluteus ludwigii on twigs of broadleaved trees. South Africa, Anungitiomyces stellenboschiensis (incl. Anungitiomyces gen. nov.) and Niesslia stellenboschiana on Eucalyptus sp. leaves, Beltraniella pseudoportoricensis on Podocarpus falcatus leaf litter, Corynespora encephalarti on Encephalartos sp. leaves, Cytospora pavettae on Pavetta revoluta leaves, Helminthosporium erythrinicola on Erythrina humeana leaves, Helminthosporium syzygii on a Syzygium sp. bark canker, Libertasomyces aloeticus on Aloe sp. leaves, Penicillium lunae from Musa sp. fruit, Phyllosticta lauridiae on Lauridia tetragona leaves, Pseudotruncatella bolusanthi (incl. Pseudotruncatellaceae fam. nov.) and Dactylella bolusanthi on Bolusanthus speciosus leaves. Spain, Apenidiella foetida on submerged plant debris, Inocybe grammatoides on Quercus ilex subsp. ilex forest humus, Ossicaulis salomii on soil, Phialemonium guarroi from soil. Thailand, Pantospora chromolaenae on Chromolaena odorata leaves. Ukraine, Cadophora helianthi from Helianthus annuus stems. USA, Boletus pseudopinophilus on soil under slash pine, Botryotrichum foricae, Penicillium americanum and Penicillium minnesotense from air. Vietnam, Lycoperdon vietnamense on soil. Morphological and culture characteristics are supported by DNA barcodes.

Computerized cognitive remediation training for schizophrenia: an open label, multi-site, multinational methodology study

A recent single-site study (Fisher et al., 2009. Am J Psychiatry. 166 (7) 805-11) showed that repeated training with the Brain Fitness Program (BFP) improved performance on a battery of neuropsychological tasks. If replicated these data suggest an important non-pharmacological method for ameliorating cognitive impairment in schizophrenia. Our study evaluated the BFP training effects in an open-label, multi-site, multinational clinical trial. Fifty-five stable adult patients with schizophrenia on regular antipsychotic medication completed ≥ 32 BFP training sessions over 8-10 weeks. Training effects on cognitive performance and functional capacity outcome measures were measured using CogState® schizophrenia battery, UCSD Performance based Skills Assessment (UPSA-2) and Cognitive Assessment Interview (CAI). BFP training showed a large and significant treatment effect on a training exercise task (auditory processing speed), however this effect did not generalize to improved performance on independent CogState® assessment. There were no significant effects on UPSA-2 or CAI scores. Our study demonstrated the feasibility of implementing BFP training in a multi-site study. However, BFP training did not show significant treatment effects on cognitive performance or functional capacity outcome measures despite showing large and significant effects on a training exercise.

Typing the HLA-B locus by a nested primer approach and oligonucleotide hybridization

A system for intermediate level identification of the HLA-B locus alleles was devised. This system can be extended to identify individual alleles in any sample. The first step used primers which amplify all HLA-B alleles. This amplicon was subjected to SSOP hybridization to allow intermediate level typing of samples. In the second step, group-specific primers were utilized to obtain specific amplification of groups consisting of a few alleles. The oligotypes within each group were identified by the use of SSOP. The separation of groups of alleles by amplification allowed the use of a limited number of probes to identify oligotypes present in a sample. Additional probes can be added as new alleles are identified, increasing the flexibility of the system. HLA typing software was developed to determine the resolution of the system and to identify HLA oligotypes. PCR-SSOP methods are in wide use and have been extensively validated. The procedures reported here will be relatively easy to implement for large-scale DNA-based typing of the HLA-B locus.

Molecular and serological characterization of HLA-B71 in association with different class I haplotypes or in different ethnic groups

The HLA-B70 antigen is among the most common antigens present in African Americans; however, monospecific serologic reagents defining B70 and its subtypes, B71 and B72, are rare. We have recently reported the molecular characterization of a B71 allele (B*1510) from an African American individual carrying the haplotype HLA-A30, Cw3, B71(w6). In order to better define the degree of polymorphism of molecules carrying the B71 serological specificity in the human population, we have used serology, cDNA sequencing, and PCR/SSOP typing to characterize B71 alleles from additional individuals from different ethnic populations and carrying different class I haplotypes. All carried either B*1510 or B*1518 alleles. Other HLA-B alleles isolated from these individuals (B*5001, B*4901, B*3501, B*3701) were identical to previously reported sequences except for a novel B41 allele (B*4102) identified in one Hispanic individual. This allele has concurrently been identified by Rufer and colleagues in Caucasian individuals. The B*4102 allele differs from B*4101 at codons 95 (Leu/Trp) and 97 (Ser/Arg). In addition, the B*4102 allele differs from B*4101 by two silent substitutions at codons 94 (ACC/ACT) and 99 (TAC/TAT). Since the polymorphic sequence present in B*4102 is also present in other HLA-B alleles (e.g.., B*2707, B*4002, B*0702), it may represent a gene conversion cassette. The allelic diversity at the class I loci and the scarcity of monospecific alloantisera support the importance of the application of molecular based methods to identify HLA class I alleles in matching unrelated donor/recipient pairs for bone marrow transplantation.

Localization and sequence analysis of morphological transforming region III within human cytomegalovirus strain Towne

A 7.6-kbp BamHI/XbaI EJ subfragment of the Towne XbaI-E fragment of human cytomegalovirus (HCMV) strain Towne has been previously designated as morphological transforming region III (mtrIII) because it induced focal and tumorigenic transformation of rodent fibroblasts. However, in two separate cell systems, mtrIII sequences were not retained because they were not detected in either the focal, tumor or tumor-derived cell lines. In this report, mtrIII was localized to a 2.1-kbp SalI/XbaI DNA fragment. The sequence of the 2,085-bp region was determined and compared to the colinear DNA from HCMV strain AD169. DNA sequence analysis revealed the presence of five open reading frames in Towne mtrIII, two of which are conserved in strain AD169. The localization and sequence analysis of mtrIII will allow further investigation as to the mechanism(s) by which HCMV may play a role in human cancer.

Localization and sequence analysis of morphological transforming region III within human cytomegalovirus strain Towne

A 7.6-kbp BamHI/XbaI EJ subfragment of the Towne XbaI-E fragment of human cytomegalovirus (HCMV) strain Towne has been previously designated as morphological transforming region III (mtrIII) because it induced focal and tumorigenic transformation of rodent fibroblasts. However, in two separate cell systems, mtrIII sequences were not retained because they were not detected in either the focal, tumor or tumor-derived cell lines. In this report, mtrIII was localized to a 2.1-kbp SalI/XbaI DNA fragment. The sequence of the 2,085-bp region was determined and compared to the colinear DNA from HCMV strain AD169. DNA sequence analysis revealed the presence of five open reading frames in Towne mtrIII, two of which are conserved in strain AD169. The localization and sequence analysis of mtrIII will allow further investigation as to the mechanism(s) by which HCMV may play a role in human cancer.

Differences in retention and expression of transfected human cytomegalovirus Towne XbaI-E transforming fragment in human cervical and NIH 3T3 lines

Human cervical and NIH 3T3 cells were transfected with the XbaI-E-transforming fragment of human cytomegalovirus strain Towne. Southern blot hybridization showed that 3 of 4 transformed NIH 3T3 cell lines retained only the mtrII subfragment of Towne XbaI-E, but not the mtrIII subfragment. Even though mtrII was retained, no viral transcripts were detected. Analysis of genomic DNAs isolated from three independently derived lines of Towne XbaI-E-transfected human exocervical epithelial cells previously immortalized by human papillomavirus type 16 (CX16-2/Towne-E) revealed the retention of both mtrII and mtrIII subfragments of Towne XbaI-E even after greater than 30 subpassages. Southern blot hybridizations indicated the integration and rearrangement of mtrII as well as mtrIII. Poly (A)+RNA analysis of CX16-2/Towne-E line revealed a 1.9-kb transcript which hybridized to mtr III. In contrast, no viral transcript from the mtrII region was detected in these cells. The pattern of HPV-16 DNA sequences and the profile of RNA transcripts were similar in the parental human exocervical cells (CX16-2) and in the CX16-2/Towne-E cells. Thus far, the CX16-2/Towne-E lines are nontumorigenic in nude mice. This study highlights not only differences in the ability of Towne XbaI-E to transform rodent cells and not human cells but also differences in the retention and expression of mtrII and mtrIII in these cells.

Identification of two promoters within human cytomegalovirus morphologic transforming region II

A 980-bp subfragment of human cytomegalovirus (HCMV) strain Towne has been previously identified as morphologic transforming region II (mtrII) because of its ability to induce focal transformation of NIH 3T3 cells. Transcripts from this region, which could encode the three open reading frames (ORFs), 79, 83, and 34 amino acids (aa), detected by DNA sequence analysis, are expressed early during HCMV infection. In this report, the mRNA start sites for promoters (P1 and P2) were mapped within Towne mtrII by primer extension using RNAs isolated from transformed NIH 3T3 cells. The Towne mtrII promoters exhibited similar activities to the SV40 enhancerless early promoter. Equivalent promoter activities were detected within the mtrII colinear nontransforming region from HCMV strain Tanaka. Two subclones of Towne mtrII (5' 440-bp and 3' 540-bp), each containing one promoter, were generated utilizing a unique BgII site which also interrupted the 79-aa ORF. In transfection assays, neither the 5' 440-bp promoter subclone containing a truncated 79-aa ORF nor the 3' 540-bp subclone containing intact 83- and 34-aa ORFs exhibited transforming activity. These data indicated that transformation by HCMV mtrII did not occur by promoter insertion. The identification of these early promoters will allow further studies on the regulation of important HCMV early genes known to be involved in viral/host interactions.

Amplified expression of ribulose bisphosphate carboxylase/oxygenase in pBR322-transformants of Anacystis nidulans

Prior research suggested that the genes for large (L) and small (S) subunits of ribulose bisphosphate carboxylase/oxygenase (RuBisCO) are amplified in ampicillin-resistant pBR322-transformants of Anacystis nidulans 6301. We now report that chromosomal DNA from either untransformed or transformed A. nidulans cells hybridizes with nick-translated [32P]-pBR322 at moderately high stringency. Moreover, nick-translated [32-P]-pCS75, which is a pUC9 derivative containing a PstI insert with L and S subunit genes (for RuBisCO) from A. nidulans, hybridizes at very high stringency with restriction fragments from chromosomal DNA of untransformed and transformed cells as does the 32P-labeled PstI fragment itself. The hybridization patterns suggest the creation of two EcoRI sites in the transformant chromosome by recombination. In pBR322-transformants the RuBisCO activity is elevated 6- to 12-fold in comparison with that of untransformed cells. In spite of the difference in RuBisCO activity, pBR322-transformants grow in the presence of ampicillin at a similar initial rate to that for wild-type cells. Growth characteristics and RuBisCO content during culture in the presence or absence of ampicillin suggest that pBR322-transformants of A. nidulans 6301 are stable. The data also collectively suggest that a given plasmid in the transformed population replicates via a pathway involving recombination between the plasmid and the chromosome.