Deep-Learning-Based Visualization and Volumetric Analysis of Fluid Regions in Optical Coherence Tomography Scans

Retinal volume computation is one of the critical steps in grading pathologies and evaluating the response to a treatment. We propose a deep-learning-based visualization tool to calculate the fluid volume in retinal optical coherence tomography (OCT) images. The pathologies under consideration are Intraretinal Fluid (IRF), Subretinal Fluid (SRF), and Pigmented Epithelial Detachment (PED). We develop a binary classification model for each of these pathologies using the Inception-ResNet-v2 and the small Inception-ResNet-v2 models. For visualization, we use several standard Class Activation Mapping (CAM) techniques, namely Grad-CAM, Grad-CAM++, Score-CAM, Ablation-CAM, and Self-Matching CAM, to visualize the pathology-specific regions in the image and develop a novel Ensemble-CAM visualization technique for robust visualization of OCT images. In addition, we demonstrate a Graphical User Interface that takes the visualization heat maps as the input and calculates the fluid volume in the OCT C-scans. The volume is computed using both the region-growing algorithm and selective thresholding technique and compared with the ground-truth volume based on expert annotation. We compare the results obtained using the standard Inception-ResNet-v2 model with a small Inception-ResNet-v2 model, which has half the number of trainable parameters compared with the original model. This study shows the relevance and usefulness of deep-learning-based visualization techniques for reliable volumetric analysis.

Dietary plant pigment on blood-digestive physiology, antioxidant-immune response, and inflammatory gene transcriptional regulation in spotted snakehead (Channa punctata) infected with Pseudomonas aeruginosa

The current study addressed to investigate the effect of lycopene (LYC) on blood physiology, digestive-antioxidant enzyme activity, specific-nonspecific immune response, and inflammatory gene transcriptional regulation (cytokines, heat shock proteins, vitellogenins) in spotted snakehead (Channa punctata) against Pseudomonas aeruginosa. In unchallenged and challenged fish treated with 200 mg LYC enriched diet the growth performance and digestive-antioxidant enzymes increased after 30 days, whereas with inclusion of 100 or 400 mg LYC in the diets, the increase manifested on or after 45 days. No mortality in fish treated with any LYC diet against P. aeruginosa was revealed. In the unchallenged and challenged fish the phagocytic (PC) activity in head kidney (HK) and spleen were significantly enhanced when fed the control diet or other LYC diets, whereas the respiratory burst (RB) activity and nitric oxide (NO) production significantly increased when fed the 200 mg diet for 45 and 60 days. Similarly, the lysozyme (Lyz) activity in the HK and spleen, and total Ig content in serum were significantly higher in both groups fed the 200 mg LYC diet for 15, 45, and 60 days. Heat shock protein (Hsp 70) was significantly improved in the uninfected group fed the 200 mg LYC diet for 45 and 60 days, but Hsp27 did not significantly change among the experimental groups at any time points. TNF-α and IL-6 mRNA pro-inflammatory cytokine expression significantly increased in both groups fed the 200 mg LYC diet after 45 and 60 days, while the IL-12 mRNA expression was moderate in both groups fed the same diet for 60 days. The IL-10 did not significant mRNA expression between groups at any sampling. The iNOS and NF-κB mRNA expression was pointedly high in both groups fed the 200 mg LYC diet on day 45 and 60. Vitellogenin A (VgA) mRNA was significantly higher in the uninfected fish fed the 100 and 200 mg LYC diets for 45 and 60 days, but VgB did not reveal significant difference between the treatment groups at any time points. The present results suggest that supplementation of LYC at 200 mg significantly modulate the blood physiology, digestive-antioxidant enzymes, specific-nonspecific immune parameters, and cytokines, Hsp, and vitellogenins in spotted snakehead against P. aeruginosa.

Role of structures in the masticator space in selecting patients with resectable T4b oral cancer: findings from a survival analysis

Oral squamous cell cancers involving the masticatory space are staged as unresectable cancers and their treatment is difficult. Curative treatment with extensive surgery followed by adjuvant therapy is one of the treatment options. In this retrospective study, the survival of 123 patients (93 with T4a cancers, 30 with T4b cancers), treated during the period August 2009 to August 2015, was evaluated. The majority had bucco-alveolar cancers (62.6%), were male (61.8%), and were tobacco users (76.4%). The select group of T4b oral cancer patients were treated with surgery, which included infratemporal fossa clearance in all 30 patients, followed by adjuvant therapy. The masseter was the most commonly involved masticatory muscle, and 24 patients had fewer than three involved structures. Free margins were obtained in 90.2% of cases; 41.5% of cases were node-positive. One hundred and four patients (84.6%) completed adjuvant treatment. The median follow-up was 42 months. For node-negative patients with T4a and T4b cancers, the 5-year overall survival was 59% and 50.2%, respectively (P= 0.62), and 5-year disease-free survival was 64.6% and 53.5%, respectively (P= 0.01). In conclusion, the select group of patients with T4b oral cancers and less than three masticatory space structures involved had comparable outcomes to those with T4a cancers after treatment with surgery and adjuvant radiotherapy.

Ten years of enzyme replacement therapy in paediatric onset mucopolysaccharidosis II in England

The outcome of 110 patients with paediatric onset mucopolysaccharidosis II (MPS II) since the commercial introduction of enzyme replacement therapy (ERT) in England in 2007 is reported. Median length of follow up was 10 years 3 months (range = 1 y 2 m to 18 years 6 month). 78 patients were treated with ERT, 18 had no ERT or disease modifying treatment 7 had haematopoietic stem cell transplant, 4 experimental intrathecal therapy and 3 were lost to follow up. There is clear evidence of improved survival (median age of death of ERT treated (n = 16) = 15.13 years (range = 9.53 to 20.58 y), and untreated (n = 17) = 11.43 y (0.5 to 19.13 y) p = .0005). Early introduction of ERT improved respiratory outcome at 16 years, the median FVC (% predicted) of those in whom ERT initiated <8 years = 69% (range = 34-86%) and 48% (25-108) (p = .045) in those started >8 years. However, ERT appears to have minimal impact on hearing, carpal tunnel syndrome or progression of cardiac valvular disease. Cardiac valvular disease occurred in 18/46 (40%), with progression occurring most frequently in the aortic valve 13/46 (28%). The lack of requirement for neurosurgical intervention in the first 8 years of life suggests that targeted imaging based on clinical symptomology would be safe in this age group after baseline assessments. There is also emerging evidence that the neurological phenotype is more nuanced than the previously recognized dichotomy of severe and attenuated phenotypes in patients presenting in early childhood.

Open Abdominal Aortic Aneurysm Replacement in the Awake Patient

Nonintubated aortic surgery using various techniques has been reported, but despite publication of favorable outcomes in select patient groups, awake aortic surgery remains unpopular. Our patient had an abdominal aortic aneurysm that was unsuitable for endovascular repair. Because of the significant respiratory disease, general anesthesia represented an unacceptably high risk. As a result, he underwent open AAA repair via a retroperitoneal approach with the aid of epidural anesthesia. Here, we highlight the benefits of the procedure which offer a select cohort of patients the chance of life-saving surgery.

How to use a controlled fast to investigate hypoglycaemia

Controlled fasts can play a valuable role in the diagnosis and management of hypoglycaemia in paediatric clinical practice, but are no substitute for the collecting of appropriate critical samples at the time of hypoglycaemia for metabolic and endocrine studies. Fatty acid oxidation defects, hyperinsulinism and adrenal insufficiency should always be excluded prior to organising controlled fasts. Controlled fasts are safe if conducted in an experienced setting with strict protocols in place. Failure to adhere to protocol can defeat the purpose of the study and can potentially be dangerous. Proper planning in conjunction with the laboratory and close supervision by staff experienced in controlled fasts is crucial to ensure the best quality information is yielded from these procedures.

Complication rate during multilevel lumbar fusion in patients above 60 years

BACKGROUND

Spine surgery in elderly with comorbidities is reported to have higher complication rates and increased cost. However, the surgical outcome is good irrespective of the complications. Hence, it is essential to identify the factors affecting the complication rates in such patients and the measures to reduce them. This retrospective observational study determines the perioperative complications, their incidence and the measures to reduce complications in the elderly with comorbidities, operated by instrumented multilevel lumbar fusion.

MATERIALS AND METHODS

Patients aged 60 years and above with one or more comorbidities operated by multilevel instrumented lumbar fusion in our center between January 2012 and December 2013 were included in the study. Perioperative complications and their incidence were calculated. Age, number of levels fused, operative time, blood loss, and complication rates were correlated with the duration of stay and the incidence of perioperative complications using SPSS software. Measures to reduce complications are determined by these results and by review of literature.

RESULTS

Fifty two patients were included in the study (28 females and 24 males) with an average age of 69 years (range 60-84 years). Hypertension was the most common comorbidity followed by diabetes. Spondylolisthesis was the most common indication. Eleven complications were noted with an incidence of 21%. Three were systemic complications which required transfer to Intensive Care Unit. Local complications were incidental durotomy (three), transient root deficits (two), wound infections (one), and persistent radicular pain (two). Operative time and blood loss were significantly higher in patients with complications.

CONCLUSION

Complication rates strongly correlate with the blood loss and operative time. Reducing the operative time and blood loss by intraoperative tranexamic acid, laminectomy using osteotome, simultaneous bilateral exposure and instrumentation and reducing the number of interbody fusions can help in reducing the complications.

Successful long-term outcome of liver transplantation in late-onset lysosomal acid lipase deficiency

Late-onset LAL deficiency, previously referred to as cholesteryl ester storage disorder, is a rare lysosomal storage disorder characterized by accumulation of cholesteryl esters. It has a heterogeneous clinical phenotype including abdominal pain, poor growth, hyperlipidemia with vascular complications and hepatosplenomegaly. End-stage liver disease may occur, but there are few reports of successful LT. There are also concerns that systemic manifestations of the disease might persist post-LT. We report a case with excellent outcome eight yr following LT. The subject was noted to have asymptomatic hepatosplenomegaly during an intercurrent illness, and LAL deficiency was confirmed with compound heterozygosity in the LIPA. Despite dietary fat restriction, he developed signs of progressive liver disease and subsequently developed hepatopulmonary syndrome. He underwent cadaveric LT at the age of nine and a half yr and recovered with prompt resolution of hepatopulmonary syndrome. Eight yr post-transplant he has normal growth, normal lipid profile, and liver and renal function tests. Liver histology showed no evidence of disease recurrence at this stage. LT in this subject resulted in an excellent functional correction of late-onset LAL deficiency.

Response of 33 UK patients with infantile-onset Pompe disease to enzyme replacement therapy

BACKGROUND

Enzyme replacement therapy (ERT) for infantile-onset Pompe disease has been commercially available for almost 10 years. We report the experience of its use in a cohort treated at three specialist lysosomal treatment centres in the UK.

METHODS

A retrospective case-note review was performed, with additional data being gathered from two national audits on all such patients treated with ERT. The impact on the outcome of various characteristics, measured just prior to the initiation of ERT (baseline), was evaluated using logistic regression.

RESULTS

Thirty-three patients were identified; 13/29 (45%) were cross-reactive immunological material (CRIM) negative, and nine were immunomodulated. At baseline assessment, 79% were in heart failure, 66% had failure to thrive and 70% had radiological signs of focal pulmonary collapse. The overall survival rate was 60%, ventilation-free survival was 40% and 30% of patients were ambulatory. Median follow-up of survivors was 4 years, 1.5 months (range 6 months to 13.5 years). As with previous studies, the CRIM status impacted on all outcome measures. However, in this cohort, baseline failure to thrive was related to death and lack of ambulation, and left ventricular dilatation was a risk factor for non-ventilator-free survival.

CONCLUSION

The outcome of treated patients remains heterogeneous despite attempts at immunomodulation. Failure to thrive at baseline and left ventricular dilation appear to be associated with poorer outcomes.

The challenges of vitamin and mineral supplementation in children with inherited metabolic disorders: a prospective trial

BACKGROUND

In order to achieve metabolic stability, dietary treatment of inborn errors of metabolism may require restriction of protein, fat or carbohydrate. Manipulation of dietary intake potentially reduces micronutrient status, and provision of a comprehensive vitamin and mineral supplement becomes an essential adjunct to dietary treatment.

AIM

To review the efficacy of a new complete vitamin and mineral supplement [Fruitivits, Vitaflo Ltd] in 14 subjects in an open prospective 26-week study.

METHOD

All subjects had dietary restrictions: low protein diets (57%, n = 8), regular daytime cornstarch and overnight glucose polymer tube feeds (29%, n = 4), low fat diet (7%, n = 1) and modified Atkins diet (7%, n = 1). Plasma nutritional biochemistry, anthropometry and food frequency questionnaires were collected at week 0, 12 and 26 weeks respectively.

RESULTS

Five nutritional parameters showed a significant improvement from baseline (week 0) to study end (week 26): folate (P = 0.01), vitamin E (P = 0.04), plasma selenium (P = 0.002), whole blood selenium (P = 0.04) and total vitamin D (P = 0.008). All the other nutritional markers did not significantly change. Even with regular monitoring, 37% of the product remained unused.

CONCLUSIONS

Despite improvements in some nutritional markers, overall use of the vitamin and mineral supplement was less than prescribed. New methods are needed to guarantee delivery of micronutrients in children at risk of deficiencies as a result of an essential manipulation of diet in inborn disorders of metabolism.

The challenges of managing coexistent disorders with phenylketonuria: 30 cases

INTRODUCTION

The few published case reports of co-existent disease with phenylketonuria (PKU) are mainly genetic and familial conditions from consanguineous marriages. The clinical and demographic features of 30 subjects with PKU and co-existent conditions were described in this multi-centre, retrospective cohort study.

METHODS

Diagnostic age of PKU and co-existent condition, treatment regimen, and impact of co-existent condition on blood phenylalanine (Phe) control and PKU management were reported.

RESULTS

30 patients (11 males and 19 females), with PKU and a co-existent condition, current median age of 14 years (range 0.4 to 40 years) from 13 treatment centres from Europe and Turkey were described. There were 21 co-existent conditions with PKU; 9 were autoimmune; 6 gastrointestinal, 3 chromosomal abnormalities, and 3 inherited conditions. There were only 5 cases of parental consanguinity. Some patients required conflicting diet therapy (n=5), nutritional support (n=7) and 5 children had feeding problems. There was delayed diagnosis of co-existent conditions (n=3); delayed treatment of PKU (n=1) and amenorrhea associated with Grave's disease that masked a PKU pregnancy for 12 weeks. Co-existent conditions adversely affected blood Phe control in 47% (n=14) of patients. Some co-existent conditions increased the complexity of disease management and increased management burden for patients and caregivers.

CONCLUSIONS

Occurrence of co-existent disease is not uncommon in patients with PKU and so investigation for co-existent disorders when the clinical history is not completely consistent with PKU is essential. Integrating care of a second condition with PKU management is challenging.

The Nutritional Intake of Patients with Organic Acidaemias on Enteral Tube Feeding: Can We Do Better?

BACKGROUND

Detailed nutritional intake data on children with organic acidaemias (OA) (propionic acidaemia (PA), vitamin B12 nonresponsive methylmalonic acidaemia (MMA) and isovaleric acidaemia (IVA)) remains unreported. Aim and subjects: A review of the longitudinal nutritional intake of 14 children with organic acidaemias (PA n = 8; MMA n = 5; IVA n = 1) dependent on enteral tube feeding (≥90% of energy requirements) from a single treatment centre.

METHODS

Nutritional intake (energy, protein, precursor-free L-amino acids, vitamins and minerals), anthropometry and nutritional biochemistry data were collated from diagnosis to current age.

RESULTS

The median energy intake was only 72% (63-137) of the estimated average DH (1991) requirement (EAR), decreasing significantly by 40% between 6 months and 5 years (p < 0.05). Total protein intake met WHO/FAO/UNU (2007) safe intake levels with median (range) precursor-free L-amino acids providing 21% (14-28) of total protein intake. Median mineral intake for sodium was 57% (20-97%), potassium 64% (27-125%) and magnesium 72% (22-116%) and was consistently < RNI for all age points. Fibre median intake was 4 g/day (0-11 g), and fluid intake provided 80% (60-100%) of the requirements for age. Linear growth was poor, and children were overweight for their height (1-10 years: z score median weight +0.6, height -1.2). Nutritional markers consistently indicated that plasma valine concentrations were < target reference ranges in PA and MMA. Iron deficiency anaemia was common in MMA/PA, and in PA, 50% of plasma zinc concentrations were < reference range.

CONCLUSION

In MMA/PA, energy intake decreases over time, weight gain accelerates, but linear height is poor. There are many nutrient deficiencies which may affect short- and long-term outcome of patients with organic acidaemias. The quality of long-term diet in these conditions deserves more attention.

Strategies for optic nerve rescue and regeneration in glaucoma and other optic neuropathies

Glaucoma is the most common age-related optic nerve disease and also the most common neuropathy, affecting approximately 60 million people worldwide in its most common forms. This figure is expected to rise to 80 million by 2020. Glaucoma is a neurodegenerative disease in which various triggers induce cascades of secondary events, which ultimately lead to apoptotic retinal ganglion cell (RGC) death. The main risk factor for glaucomatous nerve damage is raised pressure in the eye. Understanding the cascades mediating optic nerve damage enables the development of new, neuroprotective treatment strategies that might not only target the initial insult but also prevent or delay secondary neurodegeneration. Furthermore, neuroregeneration and repopulation of the visual pathway by stem or neural precursor cells is becoming possible. Increasing understanding of the pathways involved in directed axon growth and manipulation of stem and progenitor cells towards an RGC fate have facilitated first successes in animal models of glaucoma.

N-carbamylglutamate for neonatal hyperammonaemia in propionic acidaemia

Hyperammonaemia is common in neonates with branched-chain organic acidaemias, primarily due to the inhibition of N-acetylglutamate (NAG) synthetase; NAG is an activator for carbamylphosphate synthetase I, the first enzyme of the urea cycle. N-Carbamylglutamate, a NAG analogue, has been reported to correct hyperammonaemia in neonates with organic acidaemias. It is, however, uncertain how the ammonia concentrations in these neonates would have progressed without the drug. We report a neonate with propionic acidaemia, whose plasma ammonia concentration responded dramatically to N-carbamylglutamate, having previously been over 950 μmol/L for 33 h. Our patient presented with poor feeding, hypoglycaemia, acidosis and hyperammonaemia (1044 μmol/L at 65 h of age). The patient was treated with intravenous glucose (12 mg/kg per min), insulin, sodium benzoate, sodium phenylbutyrate, carnitine and continuous veno-venous haemofiltration (CVVH). In spite of these measures, the plasma ammonia concentration remained above 950 μmol/L. After 30 h of CVVH, N-carbamylglutamate (250 mg/kg) was given through a nasogastric tube. Over the following 4 h, the plasma ammonia fell from 1410 μmol/L to 267 μmol/L. Despite stopping CVVH, the ammonia level dropped to 137 μmol/L over the next 2 h and it continued to fall while the intravenous drug doses were reduced. The patient was readmitted, aged 4 weeks, with hyperammonaemia (347 μmol/L) and again this responded to N-carbamylglutamate. In contrast, we report a previous patient with propionic acidaemia who showed no response to a lower dose of N-carbamylglutamate (25 mg/kg).

Carnitine transporter defect: diagnosis in asymptomatic adult women following analysis of acylcarnitines in their newborn infants

Carnitine transporter defect (CTD) is an autosomal recessive disorder characterized by episodes of non-ketotic hypoglycaemia, hyperammonaemia and liver disease, or by the development of cardiomyopathy, both of which occur in infancy and childhood. Blood carnitine concentrations are extremely low. The diagnosis can be confirmed by finding abnormal fat oxidation and carnitine uptake in skin fibroblasts. The condition has not previously been thought to present later in life or to be benign. We report the identification of four women discovered to have CTD as a consequence of finding low carnitine concentrations in the cord blood or newborn samples from their infants. All four mothers had been asymptomatic and none had a cardiomyopathy.

Attenuated type I mucopolysaccharidosis in the differential diagnosis of juvenile idiopathic arthritis: a series of 13 patients with Scheie syndrome

OBJECTIVE

Mucopolysaccharidosis type I (MPS I) is a genetic lysosomal storage disorder caused by deficient activity of the enzyme alpha-L-iduronidase. Incomplete breakdown of glycosaminoglycans leads to progressive accumulation of these substances in many tissues throughout the body. Patients with the less severe form of MPS I (Scheie syndrome) usually present in the first decade of life with frequent articular involvement, and may survive into adulthood. Especially in these attenuated phenotypes, a definitive diagnosis may be delayed for years because clusters of early symptoms are difficult to recognize for physicians not familiar with the disease, and since the disease progresses slowly over decades. We would like to increase the awareness of this type of MPS I disease among rheumatologists and unravel diagnostic pitfalls.

METHODS

We have reviewed medical histories of 13 patients (6 males and 7 females) with Scheie syndrome seen in 5 European centers.

RESULTS

All patients had prominent musculoskeletal involvement at the onset of their disease in childhood. Diagnosis was delayed in almost all cases (range 4-54 years).

CONCLUSION

We suggest that patients who present with progressive non-inflammatory joint involvement in the first decade of life, particularly with stiffness of the fingers and difficulty using the hands, should be screened for metabolic diseases, including MPS I. MPS I should be considered if patients with arthropathy lack the typical characteristics of inflammatory arthropathy.

Prenatal diagnosis of thrombosed aneurysm of vein of Galen

Aneurysm of the vein of Galen in the fetus is a rare malformation that has been described in a small number of case reports. Thrombosis of aneurysm of the vein of Galen is a rare occurrence reported in postnatal cases. We report a case of thrombosis of vein of Galen aneurysm occurring in a fetus of 21 weeks' gestation. The fetus showed an echogenic mass posterior and superior to the thalamus. It also showed dilated dural venous sinuses, dilated neck vessels, cardiomegaly and minimal ascites. The pregnancy was terminated and autopsy confirmed the diagnosis. The present case is the first report of the prenatal sonographic features of this condition in the literature.

The receptor for advanced glycation end products (RAGE) is a cellular binding site for amphoterin. Mediation of neurite outgrowth and co-expression of rage and amphoterin in the developing nervous system

The receptor for advanced glycation end products (RAGE), a newly-identified member of the immunoglobulin superfamily, mediates interactions of advanced glycation end product (AGE)-modified proteins with endothelium and other cell types. Survey of normal tissues demonstrated RAGE expression in situations in which accumulation of AGEs would be unexpected, leading to the hypothesis that under physiologic circumstances, RAGE might mediate interaction with ligands distinct from AGEs. Sequential chromatography of bovine lung extract identified polypeptides with M(r) values of approximately 12,000 (p12) and approximately 23,000 (p23) which bound RAGE. NH2-terminal and internal protein sequence data for p23 matched that reported previously for amphoterin. Amphoterin purified from rat brain or recombinant rat amphoterin bound to purified sRAGE in a saturable and dose-dependent manner, blocked by anti-RAGE IgG or a soluble form of RAGE (sRAGE). Cultured embryonic rat neurons, which express RAGE, displayed dose-dependent binding of 125I-amphoterin which was prevented by blockade of RAGE using antibody to the receptor or excess soluble receptor (sRAGE). A functional correlate of RAGE-amphoterin interaction was inhibition by anti-RAGE F(ab')2 and sRAGE of neurite formation by cortical neurons specifically on amphoterin-coated substrates. Consistent with a potential role for RAGE-amphoterin interaction in development, amphoterin and RAGE mRNA/antigen were co-localized in developing rat brain. These data indicate that RAGE has physiologically relevant ligands distinct from AGEs which are likely, via their interaction with the receptor, to participate in physiologic processes outside of the context of diabetes and accumulation of AGEs.

Biliary and serum immunoglobulin alterations in patients of cholelithiasis

IgG, IgA and IgM were estimated in serum, common bile duct bile and gall bladder bile by single radial immunodiffusion technique in 30 patients of cholelithiasis, which included 22 patients of cholelithiasis with non functioning gall bladder (sub group A) and 8 patients of cholelithiasis with functioning gall bladder (sub group B). 30 age and sex matched controls were also included in the study. Serum IgG, IgA and IgM were significantly raised in patients of cholelithiasis as compared to controls. However, in gall bladder bile although IgA and IgM were significantly lower (more so in sub group A) than that of control group (p < 0.001 and p < 0.001 respectively but there was no change in IgG. While in common bile duct bile, rise in all the three immunoglobulins was statistically insignificant when compared to controls.

Eubacterial components similar to small nuclear ribonucleoproteins: identification of immunoprecipitable proteins and capped RNAs in a cyanobacterium and a gram-positive eubacterium

Small nuclear ribonucleoprotein (snRNP) particles play an important role in the processing of pre-mRNA. snRNPs have been identified immunologically in a variety of cells, but none have ever been observed in prokaryotic systems. This report provides the first evidence for the presence of snRNP-like components in two types of prokaryotic cells: those of the cyanobacterium Synechococcus leopoliensis and those of the gram-positive eubacterium Bacillus subtilis. These components consist of snRNP-immunoreactive proteins and RNAs, including some with the snRNP-unique 5' m2,2,7G (m3G) cap. Immunoreactivity was determined by immunoprecipitation procedures, with either antinuclear-antibody-positive (RNP- and Sm-monospecific) patient sera or a m3G monoclonal antibody, with radiolabelled cell extracts that were preadsorbed with antinuclear-antibody-negative sera. S. leopoliensis immunoprecipitates showed the presence of high-molecular-mass proteins (14 to 70 kDa) and RNAs (138 to 243 nucleotides) that are analogous in size to proteins and RNAs found in human (HEp-2) cell immunoprecipitates but absent in Escherichia coli immunoprecipitates. Thin-layer chromatography of S. leopoliensis immunoprecipitates confirmed the presence of a capped nucleotide similar to a capped nucleotide in HEp-2 immunoprecipitates; no such nucleotide was observed in E. coli immunoprecipitates. Immunoreactive RNAs (117-170 nucleotides) were identified in a second eubacterium, B. subtilis, as well. This work suggests that snRNPs or their evolutionary predecessors predate the emergence of eukaryotic cells.