Fasting plasma glucose, diagnosis of gestational diabetes and the risk of large for gestational age: a regression discontinuity analysis of routine data.

OBJECTIVE: To estimate the causal effects of fasting plasma glucose (FPG) and diagnosis of gestational diabetes (GDM) on birthweight and the risks of large for gestational age (LGA). DESIGN: Regression discontinuity analysis of routine data. SETTING: Two district general hospitals in West Yorkshire, UK. POPULATION: A cohort of 7062 women with singleton pregnancies who were screened for GDM and gave birth to a baby at ≥24 weeks of gestation in 2017-2019, inclusive. METHODS: The causal effects of FPG and GDM diagnosis were estimated using the two-stage least-squares approach, around the diagnostic threshold of FPG ≥ 5.6 mmol/l recommended by the UK's National Institute for Health and Care Excellent (NICE), controlling for ethnicity, maternal age, parity, height and weight. MAIN OUTCOME MEASURES: Birthweight (standardised for sex and gestational age) and large for gestational age (standardised as birthweight above the 90th centile). RESULTS: For each 1 mmol/l increase in FPG the observed birthweight increased by Z-score = 0.48 standard deviations (95% CI 0.39 to 0.57) and the odds of LGA increased by OR = 2.61 (95% CI 1.86 to 3.66). Conversely, GDM diagnosis reduced the observed birthweight by Z = -0.61 (95% CI -0.94 to -0.29) and lowered the odds of LGA by OR = 0.33 (95% CI 0.15 to 0.74). Similar, but less certain, patterns were observed for caesarean section, shoulder dystocia and perinatal death. CONCLUSIONS: The relationship between FPG and LGA is potent but is dramatically reduced by GDM diagnosis (and all the consequences thereof). Women with mild hyperglycaemia (with an FPG of 5.1-5.5 mmol/l) who fall below the current NICE threshold for GDM diagnosis have the highest risks of adverse outcomes, suggesting a need to reconsider their current care. TWEETABLE ABSTRACT: Regression discontinuity analysis shows that untreated mild hyperglycaemia increases the odds of large for gestational age, but that a diagnosis of gestational #diabetes lowers the odds by three times.

Using predicted 30 day mortality to plan postoperative colorectal surgery care: a cohort study.

BACKGROUND: Preoperative identification of high-risk surgical patients might help to reduce postoperative morbidity and mortality. Using a patient's predicted 30 day mortality to plan postoperative high-dependency unit (HDU) care after elective colorectal surgery might be associated with reduced postoperative morbidity. METHODS: The 30 day postoperative mortality was predicted for 504 elective colorectal surgical patients in a preoperative clinic. The prediction was used to determine postoperative surgical ward or HDU care. Those with a predicted 30 day mortality of 1-3% mortality, and thus deemed at intermediate risk, had either planned HDU care (n=68) or planned ward care (n=139). The main outcome measures were emergency laparotomy and unplanned critical care admission. RESULTS: There were more emergency laparotomies and unplanned critical care admissions in patients with a predicted 30 day mortality of 1-3% who went to an HDU after surgery compared with patients who went to a ward: 0 vs 14 (10%), P=0.0056 and 0 vs 22 (16%), P=0.0002, respectively. CONCLUSIONS: Planned postoperative critical care was associated with a lower rate of complications after elective colorectal surgery.

Adherence to consensus-based diagnosis and treatment guidelines in adult soft-tissue sarcoma patients: a French prospective population-based study.

BACKGROUND: Soft-tissue sarcomas (STSs) are rare tumors with varied histological presentations. Management and treatment are thus complex, but crucial for patient outcomes. We assess adherence to adult STS management guidelines across two French regions (10% of the French population). We also report standardized incidence. PATIENTS AND METHODS: STS patients diagnosed from 1 November 2006 to 31 December 2007 were identified from pathology reports, medical hospital records, and cancer registries. Guideline adherence was assessed by 23 criteria (validated by Delphi consensus method), and age and sex-standardized incidence rates estimated. Associations between patient, treatment, and institutional factors and adherence with three major composite criteria relating to diagnostic imaging and biopsy as well as multidisciplinary team (MDT) case-review are reported. RESULTS: Two hundred and seventy-four patients were included (57.7% male, mean age 60.8 years). Practices were relatively compliant overall, with over 70% adherence for 10 criteria. Three criteria with perfect Delphi consensus had low adherence: receiving histological diagnosis before surgery, adequacy of histological diagnosis (adherence around 50% for both), and MDT discussion before surgery (adherence <30%). Treatment outside of specialized centers was associated with lower adherence for all three composite criteria, and specific tumor sites and/or features were associated with lower adherence for diagnostic imaging, methods, and MDT meetings. STS standardized incidence rates were 4.09 (European population) and 3.33 (World) /100 000 inhabitants. CONCLUSIONS: Initial STS diagnosis and treatment across all stages (imaging, biopsy, and MDT meetings) need improving, particularly outside specialized centers. Educational interventions to increase surgeon's sarcoma awareness and knowledge and to raise patients' awareness of the importance of seeking expert care are necessary.

Ultrastructure of Presumed "Candidatus Rickettsia Andeanae" in Amblyomma maculatum (Acari: Ixodidae).

Amblyomma maculatum Koch, 1844 (also known as the Gulf Coast tick) is found in parts of the Americas, including the central and southern United States. Its primary importance is as the vector of Rickettsia parkeri, a spotted fever group rickettsia that causes an illness similar to, but milder than, Rocky Mountain spotted fever. A second spotted fever group rickettsia, "Candidatus Rickettsia andeanae," was detected in Gulf Coast ticks approximately 10 yr ago. However, the significance of this organism, including pathogenicity, has not yet been well-characterized. Here, we use transmission electron microscopy to describe bacteria within the tissues of A. maculatum ticks that were positive by polymerase chain reaction assay for "Ca. R. andeanae." In ultrathin sections of unfed A. maculatum adult females, we found evidence of bacteria with morphological features consistent with spotted fever group rickettsiae, including small size (≈0.3 by 0.9 µm), a halo zone (electron-lucent layer around the bacterium), and a trilaminar cell wall. In female ticks, bacteria were present in granular salivary glands and ducts, foregut, Malpighian tubules, nerve trunks, and reproductive tissue. These findings demonstrate evidence of "Ca. R. andeanae" in situ and contribute to our understanding of this novel rickettsia in A. maculatum.

Study of interaction between NO radicals and Martin's spirosilane by means of IR spectroscopy.

The matrix isolation method is used to record the IR spectrum of C18H8O2F12Si in the 4000-500 cm(-1) range. To gain an IR spectrum with a sufficient resolution, this technique was used with neon as the dilution medium at 5 K. The generated species were characterized by in situ fourier transform infrared (FT-IR) spectroscopy. Once the Martin's spirosilane 1 (C18H8O2F12Si) was characterized, its reactivity toward NO was investigated under the same experimental conditions (i.e., using neon as a dilution medium at 5 K). In this case, the use of neon at very low temperature leads to the formation of a chemically inert matrix in which the species are trapped and isolated from one another, thus hindering consecutive reactions. As a consequence, intermediates can be observed. This approach allowed us to characterize the NO adduct, leading to the formation of 1-(NO). Concentration effects as well as annealing experiments were carried out. In addition to this experimental approach, products were identified by using reference spectra. Our results proved that, in the dilute phase, the reaction between 1 and NO radicals leads to the formation of an adduct. This stable species can further react with NO to form a more stable compound: 1-(NO)2. This proves the ability of such species to trap NO.

Isolation of "Candidatus Rickettsia andeanae" (Rickettsiales: Rickettsiaceae) in embryonic cells of naturally infected Amblyomma maculatum (Ixodida: Ixodidae).

The Gulf Coast tick, Amblyomma maculatum Koch, has become increasingly important in public health for its role as a vector of the recently recognized human pathogen, Rickettsia parkeri. More recently, these ticks were also found to harbor a novel spotted fever group rickettsia, "Candidatus Rickettsia andeanae." First identified in Peru, and subsequently reported in ticks collected in the United States, Chile, and Argentina, "Ca. R. andeanae" remains largely uncharacterized, in part because of the lack of a stable isolate. Although the isolation of "Ca. R. andeanae" was recently described in DH82, Vero, and Drosophila S2 cells, its stability in these cell lines was not shown. To evaluate "Ca. R. andeanae" transmission and pathogenicity in vertebrates, as well as further describe biological characteristics of this candidate species to fulfill criteria for its establishment as a new species, availability of a stable isolate is essential. Here we describe the propagation of "Ca. R. andeanae" by using a primary culture derived from naturally infected A. maculatum embryos. Subsequent passage of the "Ca. R. andeanae" isolate to ISE6 (Ixodes scapularis embryonic) and Vero (African green monkey kidney epithelial) cell lines demonstrated limited propagation of the rickettsiae. Treatment of the infected primary cells with tetracycline resulted in cultures negative for "Ca. R. andeanae" by polymerase chain reaction and microscopy. Establishment of an isolate of "Ca. R. andeanae" will promote further investigation into the significance of this tick-associated rickettsia, including its role in spotted fever and interactions with the sympatric species, R. parkeri in A.

First record of Aedes japonicus japonicus in Mississippi.

In July 2011, 7 late-stage larvae of Aedes japonicus japonicus were collected from a 5-gal bucket located behind a house in Fulton, MS. Three of the larvae were reared to the adult stage, with the remaining retained in 70% ethanol. Fifteen subsequent attempts over the next month to collect specimens by larval dipping in artificial containers at the property and surrounding towns in 3 adjacent counties all failed to produce any additional Ae. j. japonicus.

Adeno-associated virus-mediated gene delivery into the scala media of the normal and deafened adult mouse ear.

Murine models are ideal for studying cochlear gene transfer, as many hearing loss-related mutations have been discovered and mapped within the mouse genome. However, because of the small size and delicate nature, the membranous labyrinth of the mouse is a challenging target for the delivery of viral vectors. To minimize injection trauma, we developed a procedure for the controlled release of adeno-associated viruses (AAVs) into the scala media of adult mice. This procedure poses minimal risk of injury to structures of the cochlea and middle ear, and allows for near-complete preservation of low and middle frequency hearing. In this study, transduction efficiency and cellular specificity of AAV vectors (serotypes 1, 2, 5, 6 and 8) were investigated in normal and drug-deafened ears. Using the cytomegalovirus promoter to drive gene expression, a variety of cell types were transduced successfully, including sensory hair cells and supporting cells, as well as cells in the auditory nerve and spiral ligament. Among all five serotypes, inner hair cells were the most effectively transduced cochlear cell type. All five serotypes of AAV vectors transduced cells of the auditory nerve, though serotype 8 was the most efficient vector for transduction. Our findings indicate that efficient AAV inoculation (via the scala media) can be performed in adult mouse ears, with hearing preservation a realistic goal. The procedure we describe may also have applications for intra-endolymphatic drug delivery in many mouse models of human deafness.

[Completeness and quality of multidisciplinary team meetings: the example of prostate cancer in the Mid-Pyrenees region]. / Exhaustivité et qualité des réunions de concertation pluridisciplinaire: l'exemple des cancers prostatiques en Midi-Pyrénées.

OBJECTIVES: To determine the completeness of the examination of cancer patient cases in a multidisciplinary team meeting (MDTM), to study the factors that can affect this examination and to assess the quality of the MDTM concerning prostate cancer in Tarn. METHODS: Completeness was estimated by comparing the database of the Tarn cancer registry containing all the inhabitants of this department for whom prostate cancer was diagnosed in 2007 with the list of patients living in Tarn whose cases were discussed during a Midi-Pyrénées MDTM. Determinants of the case discussion in MDTM were studied from data collected in medical records (age, stage at diagnosis, PSA level, Gleason score, treatment). The MDTM quality study (delay in management, whether the case was seen before or after treatment, required elements for MDTM, clinical data, conformity between suggested treatment and guidelines, adequacy between suggested and performed treatments) was based on the MDTM forms retrieved from the DCO and from medical records. RESULTS: Four hundred and fifty-nine patients were re-examined. The pretherapeutic passage rate within three months after diagnosis was 56.2%. The probability of a discussion in MDTM decreased for people over 85 years of age (OR=0.10) compared with the 70-74 year-old people and it increased for the N+M+ (OR=4.23) compared with the T1-T2. Patients for whom radiotherapy was considered were presented more frequently than the others. The MDTM quality was studied based on 220 DCO forms. The patient's physician attended the MDTM in 65% of the cases, 97% of the suggested treatments were consistent with the guidelines and 90% of the performed treatments complied with the suggested treatment. CONCLUSION: The discussion rate in MDTM has not reached the 100% planned by the first "plan cancer" yet, but when a MDTM was carried out, its compliance and adequacy were high. While seniors' cases require interdisciplinarity because of a complicated management, they were less discussed in MDTM.

SDetection of vector-borne agents in lone star ticks, Amblyomma americanum (Acari: Ixodidae), from Mississippi.

In this study, we evaluated Amblyomma americanum (lone star tick) in Mississippi for the presence of Ehrlichia chaffeensis, causative agent of human monocytic ehrlichiosis; Ehrlichia ewingii, causative agent of human and canine granulocytic ehrlichiosis; Borrelia lonestari, putative agent of southern tick-associated rash illness; Francisella tularensis, the agent of tularemia; and Rickettsia spp., particularly R. amblyommii, a suspected pathogen. We collected adult A. americanum from four regions of Mississippi: Northeast, Northwest, Southeast, and East. Of the ticks collected, 192 were dissected and DNA was extracted for nested polymerase chain reaction (PCR) assays to detect the above bacteria. In all, 3% of tick extracts had evidence of Borrelia sp., 4% for E. chaffeensis, 6% for E. ewingii, and 44% for a Rickettsia species. As determined by sequencing, most Rickettsia spp. were R. amblyommii. In addition, extracts from 42 pools (total of 950) of larval A. americanum collected in Southwest Mississippi were tested for the presence of E. chaffeensis and Rickettsia species. Of these extracts from pools, nine of 37 (24%) were PCR positive for a Rickettsia sp., most often, R. amblyommii; none had evidence of E. chaffeensis, supporting the ability of lone star ticks to transovarially transmit R. amblyommii, but not E. chaffeensis. This study demonstrates E. chaffeensis, E. ewingii, "B. lonestari", and R. amblyommii in A. americanum by PCR for the first time in Mississippi. Understanding the prevalence and epidemiology of these agents in Mississippi should increase awareness of tick-borne disease in the medical community.

Nucleated sites for the assembly of cytoplasmic microtubules in the ectodermal cells of blastulae of Arbacia punctulata.

In the ectodermal cells of sea urchin blastulae, the microtubules converge and appear to make contact with three distinct cytoplasmic foci or satellites associated with the basal body of the cilium. Beneath the nucleus, which lies in the apical end of the cell, the microtubules are aligned predominantly parallel to the cell's long axis and could thus make contact with the satellites as is directly suggested by observations on sections at or near the planes of the satellites. After the embryos are treated with low temperature (0 degrees C), the microtubules disassemble; however, the satellites can still be recognized. Upon rewarming, the microtubules reappear. In early stages of reformation, when the tubules in the cell consist of short segments, tubules have only been found in the apical part of the cell. One end of each microtubule appears to make contact with its respective satellite, or is aligned so that it could contact one of the satellites, provided serial sections were cut and collected in order. After longer periods of recovery, the microtubules elongate; as before, one end of each makes contact with a satellite or is aligned so that it could attach to a satellite. Segments of microtubules seen in the basal region of the cell are aligned parallel to the long axis of the cell as in the untreated ectodermal cells and are therefore interpreted as extensions of those tubules making contact with one of the satellites. On the basis of these observations, we suggest that assembly of microtubules is initiated at the satellites. These sites, perhaps best referred to as "nucleating sites," thereby could exert considerable control over the distribution of microtubules in cells. It is hoped that this preliminary report will be followed up by a more detailed study using serial sections.

Milankovitch hypothesis supported by precise dating of coral reefs and deep-sea sediments.

Barbados provides a possibly unique opportunity for reconstruction of the times and elevations of late-Pleistocene high stands of the sea. The island appears to be rising from the sea at a uniform rate that is fast enough to separate in elevation coral-reef tracts formed at successive high stands of the sea. Unaltered coral found in the lower terraces enables high-precision Th(230): U(234) and Pa(231): U(235) dating. Three distinct high stands of the sea are found about 122,000, 103,000, and 82,000 years ago. New Pa(231) and Th(230) dates from a deep-sea core also indicate that Ericson's W-X cold-to-warm climatic change occurred close to 126,000 years ago. These data show a parallelism over the last 150,000 years between changes in Earth's climate and changes in the summer insolation predicted from cycles in the tilt and precession of Earth's axis.

Are there variations in adherence to colorectal cancer clinical guidelines depending on treatment place and recommendation novelty? The French EvaCCoR observational study.

BACKGROUND: Studies have shown clinical practices variation between centers in colorectal cancer (CRC) management. After the implementation of national cancer plans, we tested for differences in center and patients' socioeconomic position (SEP)-related variation in CRC guidelines. METHODS: All patients aged 18 years and over, cared for a first CRC in 2010 in Southwest of France. We used mixed effect model to test for center-related heterogeneity (CRH) in recommendation, from the oldest to the more recent: (1) at least 12 lymph nodes analysed for stage II, (2) the prescription of adjuvant chemotherapy stage III and (3) the assessment of CRC molecular phenotype regarding KRAS status for stage IV. Patients' SEP was approached by an ecological social deprivation index. RESULTS: We found: higher adherence for the oldest than for the most recent recommendations; no CRH in recommendation No. 2 but lower adherence in academic centers; a CRH for recommendations No. 1 and 3; no SEP-related differences in clinical practices. CONCLUSION: Results showed that older recommendations have higher adherence but did not support increasing influence of centers characteristics and CRH as recommendations are more recent.

Multidisciplinary team meeting and EUSOMA quality indicators in breast cancer care: A French regional multicenter study.

INTRODUCTION: We evaluate breast cancer (BC) pathway at a regional level including public, private and university institutions. We assessed the quality of multidisciplinary team meetings (MTM) and compliance with a panel of European high-quality indicators (EUSOMA QIs). METHODS: We conducted a retrospective multicenter (n = 20) study in the largest health care region in France. Between January and April 2015, we included all patients discussed at an MTM after a diagnosis of BC (n = 619). We analyzed quality of MTM by assessing the quorum, the reliability of data transcription and the exhaustivity of pre-therapeutic MTM. We then analyzed the compliance with a selected panel of 16 EUSOMA QIs. RESULTS: During MTM discussion, data were more than 95% consistent with medical records for 9/11 items. Pre-operative tumor histology (90.6%) and post-operative resection margins (84.3%) were the least concordant between medical records and MTM. Minimum standards as defined by EUSOMA were reached for 11/16 QIs, but not reached for pathology reports in non-invasive BC (78.2%), proportion of exclusive sentinel lymph node biopsies in patients with clinically negative axilla (85.2%), performing adjuvant chemotherapy (76.6%), and proportion of patients discussed in pre-therapeutic and post-operative MTM (63.5%). CONCLUSIONS: In this multicentric study evaluating the quality of BC care with a representative sample of institutions, compliance with EUSOMA indicators was satisfactory for all type of institutions. However, too few patients were discussed in pre-therapeutic MTM (especially in non-university hospitals 43.7% [39.4-48.1]) versus 88.7% for others [82.2-95.1]) and data transcription was likely responsible for up to 15% of discordance.

Additions to the known U.S. distribution of Latrodectus geometricus (Araneae: Theridiidae).

The range of the brown widow spider Latrodectus geometricus C. L. Koch includes much of Africa and South and Central America. This medically important spider has been recently introduced to Japan, Indonesia, Papua New Guinea, Australia, Hawaii, and California. After the identification of the brown widow spider in New Orleans, LA, and southern Mississippi, surveys in the southeastern United States were conducted from the fall of 2006 through February 2008. We found populations of brown widow spiders in Georgia, Texas, and multiple localities in southeastern Louisiana and Mississippi. In Mississippi, specimens were collected as far north as a county bordering Tennessee. In New Orleans, the brown widow spider has been commonly collected from various locations where human contact is likely.

Rechargeable antimicrobial surface modification of polyethylene.

Polyethylene films were surface modified, to incorporate amine and amide functionalities, and subsequently were evaluated for their ability to recharge the antimicrobial N-halamine structures after contact with sodium hypochlorite, a common food-approved sanitizer. Surfaces were tested for chlorine retention and release, as well as antimicrobial activity against microorganisms relevant to food quality and food safety, including Escherichia coli K-12, Pseudomonas fluorescens, Bacillus cereus, and Listeria monocytogenes. N-Halamine functionalized polyethylene exhibited chlorine rechargeability, maintaining 5 to 7 nmol/cm2 N-halamine structures for six successive charges. The N-halamine functionalized films achieved a 4-log reduction for all organisms tested and maintained a greater than 3-log reduction for four successive uses, suggesting that the modified polyethylene films are capable of providing rechargeable antimicrobial activity. The modified films exhibited antimicrobial activity in aqueous suspensions (P < 0.05) and reduced microbial growth in diluted broth (P < 0.05), suggesting the potential for biocidal action even in the presence of organic matter. Such a rechargeable antimicrobial surface could supplement existing cleaning and sanitation programs in food processing environments to reduce the adhesion, growth, and subsequent cross-contamination of food pathogens, as well as food spoilage organisms.

Effect of acute paracetamol overdose on changes in serum and urine electrolytes.

AIMS: To investigate the effects of acute paracetamol overdose on renal function, serum and urine electrolyte excretion in man. METHODS: Two studies were performed in patients admitted with paracetamol overdose: a retrospective study examining changes in serum electrolytes, and a prospective study evaluating changes in serum and urine electrolytes. A control group with SSRI overdose was included in the prospective study. RESULTS: There was a significant dose-dependent relationship between admission (4 h) paracetamol concentration and fall in serum potassium in the retrospective study (P < 0.01) and a significant positive relationship between serum paracetamol at 4 h and fractional excretion of potassium at 12 h postingestion (P < 0.01) in the prospective study. No changes were seen in the control group. No cases developed renal failure. CONCLUSIONS: Paracetamol overdose is associated with dose-related hypokalaemia, and kaliuresis of short duration (<24 h), suggesting a specific renal effect of paracetamol in overdose perhaps via cyclo-oxygenase inhibition. This effect seems distinct from any nephrotoxic effect of paracetamol.

Inactive chromatin spreads from a focus of methylation.

The detailed mechanisms of inhibition of transcription by DNA methylation are still unknown, but it has become obvious that the formation of chromatin plays an important role in this process. Using an approach enabling us to methylate, in vitro, chosen regions in a plasmid, we now show that specific methylation of nonpromoter sequences results in transcriptional inhibition of a reporter gene construct and that this inhibition is independent of the position of the methylated region within the plasmid. In plasmid minichromosomes containing a short region of methylated DNA, both methylated and unmethylated sequences are protected from limited MspI digestion. Our results show that inactive chromatin is present at unmethylated regions in partially methylated minichromosomes and can thereby inhibit gene expression. Spreading of the inactive chromatin is not inhibited by the presence of active promoters, nor is it a consequence of transcriptional inactivity.

Expression of a cDNA sequence encoding human purine nucleoside phosphorylase in rodent and human cells.

A cDNA sequence which contains the entire coding region for human purine nucleoside phosphorylase (PNP) was recombined for selection and expression in mammalian cells. Plasmids containing either the simian virus 40 early promoter or the mouse metallothionein promoter positioned just upstream of the PNP coding sequence were constructed. These plasmids also contained the gene for a methotrexate-resistant dihydrofolate reductase, allowing for selection and amplification of positive transferrents after transfection of cells by the DNA-calcium phosphate coprecipitation technique. Expression of human PNP activity was readily detected in both mouse (L) and CHO cells by isoelectric focusing of cell extracts followed by histochemical staining for PNP activity. The simian virus 40 early promoter directed considerable expression of human PNP activity in CHO cells but only scant activity in mouse cells. The mouse metallothionein promoter was not successful in effecting human PNP expression in CHO cells but provided substantial human PNP activity in mouse cells and was inducible by incubation with zinc. HeLa cell transferrents were isolated and screened for the presence of transferred PNP cDNA sequences by Southern hybridization analysis. RNA transcripts derived from the transferred PNP cDNA were identified in one of these cell lines.

Theoretical studies of the conformations and 19F NMR spectra of linear and a branched perfluorooctanesulfonamide (PFOSAmide).

Technical perfluorooctanesulfonate (PFOS) and its derivatives, such as perfluorooctanesulfonamide (PFOSA), are not clean compounds but, instead, complex mixtures of linear and branched isomers, and other compounds including sulfonate homologues. Questions have been raised as to whether the linear and the branched isomers behave differently in the environment. However, little is known about the physical properties or the finer details of the structures of the individual branched isomers. This study sought an effective computational method to model the preferred conformations of PFOS derivatives, and the energy differences between them and to determine if these results can be used to explain the temperature dependence of their NMR spectra. Good predictions of the 19F chemical shifts were obtained for some PFOSA-type molecules with a computational approach [B3LYP-GIAO/6-31++G(d,p)//B3LYP/6-31G(d,p)] that is relatively inexpensive. Large 5JFF couplings found in one of the branched isomers could be rationalized on the basis of the relevant F-F distances in the optimized structure. At low temperatures, the splitting observed in the NMR spectrum at C-1 for these sulfonamides can be explained by the existence of the two conformers predicted by the computations.