A 1-year follow-up study on checkpoint inhibitor-induced colitis: results from a European consortium.

BACKGROUND: Data regarding the clinical outcome of patients with immune checkpoint inhibitor (ICI)-induced colitis are scant. We aimed to describe the 12-month clinical outcome of patients with ICI-induced colitis. MATERIALS AND METHODS: This was a retrospective, European, multicentre study. Endoscopy/histology-proven ICI-induced colitis patients were enrolled. The 12-month clinical remission rate, defined as a Common Terminology Criteria for Adverse Events diarrhoea grade of 0-1, and the correlates of 12-month remission were assessed. RESULTS: Ninety-six patients [male:female ratio 1.5:1; median age 65 years, interquartile range (IQR) 55.5-71.5 years] were included. Lung cancer (41, 42.7%) and melanoma (30, 31.2%) were the most common cancers. ICI-related gastrointestinal symptoms occurred at a median time of 4 months (IQR 2-7 months). An inflammatory bowel disease (IBD)-like pattern was present in 74 patients (77.1%) [35 (47.3%) ulcerative colitis (UC)-like, 11 (14.9%) Crohn's disease (CD)-like, 28 (37.8%) IBD-like unclassified], while microscopic colitis was present in 19 patients (19.8%). As a first line, systemic steroids were the most prescribed drugs (65, 67.7%). The 12-month clinical remission rate was 47.7 per 100 person-years [95% confidence interval (CI) 33.5-67.8). ICI was discontinued due to colitis in 66 patients (79.5%). A CD-like pattern was associated with remission failure (hazard ratio 3.84, 95% CI 1.16-12.69). Having histopathological signs of microscopic colitis (P = 0.049) and microscopic versus UC-/CD-like colitis (P = 0.014) were associated with a better outcome. Discontinuing the ICI was not related to the 12-month remission (P = 0.483). Four patients (3.1%) died from ICI-induced colitis. CONCLUSIONS: Patients with IBD-like colitis may need an early and more aggressive treatment. Future studies should focus on how to improve long-term clinical outcomes.

Voluntary and controlled weight loss can reduce symptoms and proton pump inhibitor use and dosage in patients with gastroesophageal reflux disease: a comparative study.

A wide variety of pieces of evidence has suggested that obesity is associated with a significant increase in the risk for gastroesophageal reflux disease (GERD) symptoms and its complications. The aim of this study was to evaluate the effect of weight loss on reflux symptoms in overweight/obese patients with proven GERD. We enrolled overweight/obese patients with typical GERD symptoms and erosive esophagitis. At baseline, patients underwent detailed reflux symptoms evaluation and anthropometric assessment, and were divided into two treatment groups: group A received proton pump inhibitor (PPI) and a personalized hypocaloric diet and aerobic exercise; and group B received PPI and a 'standard of care diet'. The dietetic treatment was considered effective if at least 10% of weight loss was achieved within 6 months. All patients were evaluated in terms of anthropometric data, GERD symptoms, and PPI use. In group A, mean body mass index (BMI) decreased from 30.3 ± 4.1 to 25.7 ± 3.1 (P < 0.05), and mean weight decreased from 82.1 ± 16.9 kg to 69.9 ± 14.4 kg (P < 0.05). In group B, there was no change in BMI and weight. Symptom perception decreased (P < 0.05) in both groups during PPI therapy, but a higher improvement was recorded in group A. In group A, PPI therapy was completely discontinued in 27/50 of the patients, and halved in 16/50. Only 7/50 continued the same PPI dosage. In group B, 22/51 halved the therapy and 29/51 maintained full dosage of therapy, but none was able to discontinue PPI due to a symptom recurrence. Overall, weight loss of at least 10% is recommended in all patients with GERD in order to boost the effect of PPI on reflux symptom relief and to reduce chronic medication use.

Lower pH values of weakly acidic refluxes as determinants of heartburn perception in gastroesophageal reflux disease patients with normal esophageal acid exposure.

Multichannel impedance pH monitoring has shown that weakly acidic refluxes are able to generate heartburn. However, data on the role of different pH values, ranging between 4 and 7, in the generation of them are lacking. The aim of this study was to evaluate whether different pH values of weakly acidic refluxes play a differential role in provoking reflux symptoms in endoscopy-negative patients with physiological esophageal acid exposure time and positive symptom index and symptom association probability for weakly acidic refluxes. One hundred and forty-three consecutive patients with gastroesophageal reflux disease, nonresponders to proton pump inhibitors (PPIs), were allowed a washout from PPIs before undergoing: upper endoscopy, esophageal manometry, and multichannel impedance pH monitoring. In patients with both symptom index and symptom association probability positive for weakly acidic reflux, each weakly acidic reflux was evaluated considering exact pH value, extension, physical characteristics, and correlation with heartburn. Forty-five patients with normal acid exposure time and positive symptom association probability for weakly acidic reflux were identified. The number of refluxes not heartburn related was higher than those heartburn related. In all distal and proximal liquid refluxes, as well as in distal mixed refluxes, the mean pH value of reflux events associated with heartburn was significantly lower than that not associated. This condition was not confirmed for proximal mixed refluxes. Overall, a low pH of weakly acidic reflux represents a determinant factor in provoking heartburn. This observation contributes to better understand the pathophysiology of symptoms generated by weakly acidic refluxes, paving the way toward the search for different therapeutic approaches to this peculiar condition of esophageal hypersensitivity.

Genome Sequence of Magnetospirillum magnetotacticum Strain MS-1.

Here, we report the genome sequence of Magnetospirillum magnetotacticum strain MS-1, which consists of of 36 contigs and 4,136 protein-coding genes.

Proton pump inhibitor responders who are not confirmed as GERD patients with impedance and pH monitoring: who are they?

BACKGROUND: A short-course of proton pump inhibitors (PPIs) is often used to confirm gastroesophageal reflux disease (GERD). However, some patients with PPI responsive heartburn do not seem to have evidence of GERD on impedance-pH monitoring (MII-pH). The aim of the study was to evaluate patients with reflux symptoms and a negative endoscopy, who well respond to PPIs with MII-pH. METHODS: We enrolled 312 patients with GERD symptoms and negative endoscopy: 144 reported well-controlled symptoms after 8-week PPIs and 155 were non-responders. Symptom relief was evaluated with GERD Impact Scale and visual analog scale score. All patients underwent MII-pH off-therapy. Thirteen patients were excluded from analysis. Patients were grouped as follows: non-erosive reflux disease (NERD; increased acid exposure time, AET); hypersensitive esophagus (HE; normal AET, positive symptom association, SI/SAP); MII-pH-/PPI+ (normal AET, negative SI/SAP) in the responder group; MII-pH-/PPI- in non-responders. KEY RESULTS: MII-pH in PPI responders (symptom relief during PPI therapy > 75%) showed: 79/144 NERD (54.9%); 37/144 HE (25.7%); 28/144 MII-pH-/PPI+ (19.4%). MII-pH-/PPI+ patients reported the same symptom relief when compared with NERD and HE. In non-responder (symptom relief during PPI therapy < 50%) group, 27/155 patients were NERD (17.4%); 53/155 were HE (34.2%); 75/155 were MII-pH-/PPI- (48.4%). NERD diagnosis was significantly higher in responder group (p < 0.01). CONCLUSIONS & INFERENCES: In a substantial subgroup of patients responding to PPI with typical reflux symptoms, the diagnosis of GERD cannot be confirmed with pH-impedance monitoring. Proton pump inhibitor response and presence of typical symptoms are thus not reliable predictors of the diagnosis and antireflux surgery should always be preceded by reflux monitoring.

Long-term use of nerve block catheters in paediatric patients with cancer related pathologic fractures.

We report three cases of children with osteosarcoma and pathologic fractures treated with long-term continuous nerve blocks for preoperative pain control. One patient with a left distal femoral diaphysis fracture had a femoral continuous nerve block catheter for 41 days without complications. Another with a fractured left proximal femoral shaft had three femoral continuous nerve block catheters for 33, 26 and 22 days respectively. The third patient, whose right proximal humerus was fractured, had a brachial plexus continuous nerve block catheter for 36 days without complication. In our experience, prolonged use of continuous nerve block is safe and effective in children with pathologic fractures for preoperative pain control.

Physical and genetic characterization of the genome of Magnetospirillum magnetotacticum, strain MS-1.

Pulsed-field gel analysis of Magnetospirillum magnetotacticum, strain MS-1, indicates that the genome is a single, circular structure of about 4.3 mb. A few genes, identified by sequence similarity, have been localized and arranged in a map with dnaA, indicating the presumed origin of replication. There are at least two rRNA operons. In addition, rRNA genes are found on a 40 kb, possibly extrachromosomal, structure. The genes thought to be involved in magnetite synthesis, bfr and magA, are located in the same 17% of the genome. A one base pair-overlap seen in the bfr genes of MS-1 is found also in the closely related magnetic strain AMB-1, but not in the non-magnetic relative A. itersonii.

Paleoproterozoic snowball earth: extreme climatic and geochemical global change and its biological consequences.

Geological, geophysical, and geochemical data support a theory that Earth experienced several intervals of intense, global glaciation ("snowball Earth" conditions) during Precambrian time. This snowball model predicts that postglacial, greenhouse-induced warming would lead to the deposition of banded iron formations and cap carbonates. Although global glaciation would have drastically curtailed biological productivity, melting of the oceanic ice would also have induced a cyanobacterial bloom, leading to an oxygen spike in the euphotic zone and to the oxidative precipitation of iron and manganese. A Paleoproterozoic snowball Earth at 2.4 Giga-annum before present (Ga) immediately precedes the Kalahari Manganese Field in southern Africa, suggesting that this rapid and massive change in global climate was responsible for its deposition. As large quantities of O(2) are needed to precipitate this Mn, photosystem II and oxygen radical protection mechanisms must have evolved before 2.4 Ga. This geochemical event may have triggered a compensatory evolutionary branching in the Fe/Mn superoxide dismutase enzyme, providing a Paleoproterozoic calibration point for studies of molecular evolution.

Evidence for two types of subunits in the bacterioferritin of Magnetospirillum magnetotacticum.

In order to investigate the role of bacterioferritin (Bfr) in the biomineralization of magnetite by microorganisms, we have cloned and sequenced the bfr genes from M. magnetotacticum. The organism has two bfr genes that overlap by one nucleotide. Both encode putative protein products of 18 kDa, the expected size for Bfr subunits, and show a strong similarity to other Bfr subunit proteins. By scanning the DNA sequence databases, we found that a limited number of other organisms, including N. gonorrhea, P. aeruginosa, and Synechocystis PCC6803, also have two bfr genes. When the sequences of a number of microbial Bfrs are compared with each other, they fall into two distinct types with the organisms mentioned above having one of each type. Differences in heme- and metal-binding sites and ferroxidase activities of the two types of subunits are discussed.

The isolation and characterization of the gene (dfr1) encoding dihydrofolate reductase (DHFR) in Schizosaccharomyces pombe.

A sequence encoding dihydrofolate reductase (DHFR) was isolated from a Schizosaccharomyces pombe cDNA library by selecting for trimethoprim resistance in Escherichia coli. The sequence was found to be functional in both Saccharomyces cerevisiae and Sz. pombe. When present on a multicopy plasmid, it confers increased resistance to concentrations of the drug methotrexate that are otherwise inhibitory for the standard yeast strains. The sequence was mapped by DNA hybridizations between genes adh1 and ade5 on chromosome III of Sz. pombe. The 1.6-kb insert contains a 1.5-kb open reading frame (ORF) with strong sequence similarity to other described DHFR-encoding genes. The similarity, however, is limited to a 678-bp sequence, occupying the 3'-half of the ORF. No similarity to other described DNA sequences or proteins could be found for the 5'-half. Southern and Northern blots indicate that the entire insert is present intact in the Sz. pombe genome and produces a 1.7-kb RNA transcript.

Control of prophage integration and excision in bacteriophage P2: nucleotide sequences of the int gene and att sites.

Integration of bacteriophage P2 into the Escherichia coli host genome involves recombination between two specific attachment sites, attP and attB, one on the phage and the other on the host genome, respectively. The reaction is controlled by the product of the phage int gene, a basic polypeptide of about 37 kDa [Ljungquist and Bertani, Mol. Gen. Genet. 192 (1983) 87-94]. The int gene appears to be expressed differently by an infecting phage, as opposed to a prophage [Bertani, Proc. Natl. Acad. Sci. USA 65 (1970) 331-336]. A 1200-bp region of P2 DNA containing the int gene and attP, the prophage hybrid ends attL and attR, and one bacterial attachment site, the preferred site locI from E. coli strain C, have all been sequenced. An open reading frame coding for a polypeptide of 337 amino acids corresponds to the int gene. The gene has no obvious promoter sequence preceding it. The int gene transcript seems to continue past the attP site downstream from it, suggesting a possible explanation for the previously observed difference in integration and excision. A comparison of the four attachment sites reveals a common 'core' sequence of 27 bp: 5'-AAAAAATAAGCCCGTGTAAGGGAGATT-3'. The P2 nip1 mutation, which increases prophage excision [Calendar et al., Virology 47 (1972) 68-75], was found to lie within the int gene itself. The P2 saf variant, which has altered site preference [Six, Virology 29 (1966) 106-125], has a bp substitution within the core sequence. Three deletion/substitution mutants, vir22, vir94 and del3, also have altered core sequences.

DNA sequences of bacteriophage P2 early genes cox and B and their regulatory sites.

Part of the early operon of the temperate phage P2 of Escherichia coli, including genes cox (involved in prophage excision) and B (required for phage specific DNA synthesis), was sequenced. The results are consistent with an early promoter spanning the repressor binding sites, a leader sequence of about 80 bases which overlaps the leader sequence of the repressor gene for about 30 bases, and coordinate transcription of genes cox and B with a termination signal after the B gene. In addition, the data provide amino acid sequences for the Cox and B proteins of 91 and 166 residues, respectively and reveal a hitherto undetected coding sequence between genes cox and B that has the potential to produce a very basic polypeptide of 56 residues. Slight structural similarities between the P2 Cox protein and the analogous Xis protein of phage lambda were noted and the P2 B gene product was compared with proteins that interact with the DnaB protein of E. coli.

DNA sequences of the repressor gene and operator region of bacteriophage P2.

The nucleotide sequence of the repressor gene C of the temperate phage P2 has been determined. It codes for a nonbasic polypeptide, 99 amino acids long. Twelve repressor-defective mutants have been mapped. All but one are located within the presumed coding part of the gene. There is a strong promoter sequence and an 8-base-pair inverted repeat preceding the gene. The P2 repressor protein shows structural similarity to other DNA-binding proteins. The operator region for the early replication functions was located by sequencing the DNA of three virulent mutants. The sequence indicates that there are two repressor-binding sites. In addition, one of the sites shows sequence homology with part of the operator region of the biotin operon of Escherichia coli.

Properties and products of the cloned int gene of bacteriophage P2.

Fragments of DNA of the temperate phage P2, generated by treatment with the restriction enzyme PstI, have been cloned into the plasmid pBR322. One such fragment, which has its endpoints within phage genes T and C, carries the structural P2 int gene as well as its promoter and the phage att site. When introduced into a suitable bacterial host, the cloned fragment mediates the integration and excision of int- mutants of P2 and recombination within the phage att site in mixed infection. All these activities are independent of the orientation of the fragment within the plasmid. When introduced into minicells, the fragment produces, in addition to the products of genes D and U, a protein of 35-37,000 daltons identified as the int protein. A study of the map location of two amber int mutants, together with the sizes of the polypeptides they produce, indicates that the P2 int gene is transcribed from right to left on the P2 map, i.e. starting near gene C and proceeding toward att.

Milk precipitins in selective IgA deficiency.

Precipitating antibody to cow milk's antigens (commonly bovine IgM) is found in 40-50% of selective IgA deficient patients. These precipitins may obscure the diagnosis of selective IgA deficiency by formation of anti-antiserum precipitin rings in radial immunodiffusion. Abnormal immunoregulatory function along with excess absorption of milk antigens in the absence of secretory IgA may be predisposing factors. Elimination of dietary cow's milk results in disappearance of these antibodies.