Transthyretin amyloid cardiomyopathy among patients with heart failure and preserved ejection fraction: the AMY score

AIMS

Transthyretin 'wild-type' amyloid cardiomyopathy (ATTRwt-CM) is a differential diagnosis of heart failure with preserved ejection fraction (HFpEF). The clinical work-up for ATTRwt-CM is challenging. Considering a combination of clinical variables specific for ATTRwt-CM might aid in identifying patients at risk.

METHODS AND RESULTS

Sixty patients (78 ± 6 years, 8% female) were diagnosed with ATTRwt-CM by endomyocardial biopsy. Preserved ejection fraction (LVEF >45%) was present in 41 of the patients. Those were 1:1 propensity score age- and sex-matched to a cohort of patients with HFpEF. ATTRwt-CM patients had less obesity (P = 0.01) and higher septal thickness (IVSd, P < 0.01) as well as more diastolic dysfunction (E/e', P < 0.01). On multivariable regression IVSd > 14 mm, E/e' > 14 and absence of obesity (P > 0.01 for all) were identified as predictors for ATTRwt-CM. A weighted point-based score was derived with IVSd > 14 mm = 1 point; absence of obesity = 2 points; and E/e' > 14 = 3 points. Area under the curve (AUC) for the summation score was 0.91 (0.84-0.97, P < 0.01) and a score of more than 3 points predicted ATTRwt-CM with good sensitivity (78%) and specificity (90%). The score was validated in an external cohort of 142 patients with ATTRwt-CM and 419 HFpEF patients showing sufficient accuracy (AUC 0.91, 0.88-0.94, P < 0.01). A value greater than 3 points demonstrated a high sensitivity (93%) and a negative predictive value of 97%.

CONCLUSIONS

A score based on basic clinical and echocardiographic features helps to distinguish ATTRwt-CM from typical HFpEF. This could facilitate the diagnostic work-up for these patients and enable earlier disease screening on a large scale.

Clinical Trajectory and Risk Stratification for Heart Failure with Preserved Ejection Fraction in a Real-World Cohort of Patients with Suspected Coronary Artery Disease

Background: Heart failure with preserved ejection fraction (HFpEF) is a widespread condition with significant morbidity and mortality. Its clinical heterogeneity may delay the diagnosis. Aim: To identify predictors of HFpEF-related hospitalizations in ambulatory patients presenting with elevated cardiovascular risk, suspected coronary artery diseases (CADs), and positive HFpEF screenings. Methods: Consecutive patients presenting with suspected CAD, enrolled in the observational LIFE-Heart study (2006-2014, NCT00497887), and meeting HFpEF criteria per the 2016 European Society of Cardiology (ESC) guidelines were categorized according to the presence of "overlapping conditions" potentially masking or contributing to their symptoms. Additional stratification using the H2FPEF score (<2: low risk, 2-5: intermediate risk, and ≥6 high risk) was performed. Follow-up for hospitalizations, reasons of hospitalization, and death spanned a median of 6 years. Results: Of 1054 patients (66 ± 10 years, 60% male, NT-pro-BNP 286, IQR 183-574 pg/mL), 53% had overlapping conditions, while 47% had "isolated HFpEF". The H2FPEF scores classified 23%, 57%, and 20% as low-, intermediate-, and high-risk, respectively, with consistent proportions across patients with and without overlapping conditions (p = 0.91). During the follow-up observational phase, 54% were rehospitalized, 22% experienced heart failure (HF) rehospitalizations, and 11% of patients died. Multivariable logistic regression revealed a high-risk H2FPEF category as an independent predictor of HF rehospitalization in the overall cohort (odds ratio: 3.4, CI: 2.4-4.9, p < 0.01) as well as in patients with and without overlapping conditions. Furthermore, a H2FPEF score ≥ 6 was independently associated with higher mortality rates (hazard ratio: 1.8, CI: 1.2-2.6, p < 0.01) in the Cox regression analysis. Conclusions: Ambulatory patients presenting for suspected CAD and meeting HFpEF screening criteria face elevated risks for rehospitalizations over six years. Regardless of concomitant diagnoses, quantifying cardiac damage with the H2FPEF score helps in risk-stratifying patients for HF hospitalization and mortality.

Frequency of non-aureus staphylococci and mammaliicocci species isolated from quarter clinical mastitis: a six-year retrospective study

Non-aureus staphylococci and mammaliicocci (NASM) are the most frequently isolated bacterial group from bovine milk samples. Most studies focus on subclinical mastitis caused by NASM, however NASM can cause clinical mastitis (CM) as well. We evaluated retrospective data from 6 years (2017-2022) to determine the species and frequency of NASM isolated from quarter bovine CM. The data comprised of microbiological results from quarter CM samples routinely submitted to Quality Milk Production Services (QMPS), Cornell University, NY, US, for microbial identification by MALDI-TOF MS. A total of 9,909 microbiological results from 410 dairy herds were evaluated. Our results showed that 29 distinct NASM species were identified, with the 8 most prevalent NASM species being Staphylococcus chromogenes, S. haemolyticus, S. simulans, S. epidermidis, S. sciuri (now Mammaliicoccus sciuri), S. agnetis/S. hyicus, S. borealis, and S. xylosus. The NASM distribution remained similar among seasons, but the frequency of NASM CM cases was higher during the summer. Our results showed different patterns of variations in the isolation frequency over time, depending on the bacterial species: increasing or decreasing trends, cyclic fluctuations, and except for S. borealis, a significant seasonality effect for our study's most prevalent NASM was observed. This study showed that S. chromogenes remains the most frequent (43%) NASM species identified from bovine CM, followed by S. haemolyticus (18%), and S. simulans (12%).

Genomic Characterization of Mycoplasma arginini Isolated from a Housefly on a Dairy Farm and Comparison with Isolates from Bovine Milk and Lung Tissue

Mycoplasma mastitis can be highly contagious, unresponsive to treatment, and cause severe economic problems in affected herds. Notable routes of Mycoplasma spp. transmissions are contaminated milking equipment and animal contact through respiratory secretions. Only a few studies report the environment as a possible source of infection. Our group studied the presence of pathogens in houseflies (Musca domestica) in a New York State dairy in the United States. Among others, a Mycoplasma spp. was found in the gut of a housefly captured in the sick pen and identified as M. arginini. Here, we characterized its genome and investigated its relatedness with eight isolates from milk, one isolate from lung tissue collected in the same dairy, and five other dairies in New York State. We applied whole-genome sequencing and phylogenetic analysis based on the sequences of the 16S rRNA gene and 76 conserved proteins. We also assessed an in silico virulence profile by considering a panel of 94 putative virulence genes. As a result of the genome analysis, the housefly M. arginini isolate was highly similar to the milk isolates; interestingly, the similarity was highest with M. arginini isolated from milk on the same dairy farm where the housefly was captured. The housefly and milk M. arginini isolates possessed 54 of the 94 pathogenicity genes considered. Our data support the hypothesis that houseflies are carriers of Mycoplasma spp. and can be considered within the possible roots of environmental transmission of infection in dairy cows. Nevertheless, M. arginini pathogenicity will need to be investigated with dedicated studies. IMPORTANCE It is critical to control the spread of bovine mastitis caused by Mycoplasma spp., as this disease can be highly contagious and have a severe economic impact on affected dairies. A better understanding of possible transmission routes is crucial for infection control and prevention. Based on our data, the composite milk isolates are genetically similar to the housefly isolate. This provides evidence that the same Mycoplasma species found in milk and associated with mastitis can also be isolated from houseflies captured in the dairy environment.

Pathogens associated with houseflies from different areas within a New York State dairy

Houseflies (Musca domestica) are nonbiting muscoids of importance because they can be mechanical vectors of many kinds of pathogens such as bacteria, protozoa, viruses, and helminth eggs. This study aimed to evaluate the bacterial communities associated with houseflies captured in 3 different areas on a dairy farm located in New York State. Variations in the bacterial community were also evaluated based on the flies' sex and external or internal location where the bacteria were isolated. A total of 101 flies were collected: 27 flies from the sick pen, 42 from calf hutches, and 32 from the milking parlor. A total of 485 organisms were isolated, 233 (48.0%) from 53 female flies and 252 (52.0%) from 48 male flies. Most (74%) bacteria were found in the internal parts of the flies, with only 26% isolated from the external surfaces. The number of isolates detected per fly ranged between 1 and 11. A total of 392 bacteria were identified at the species level. We isolated 26 species reported to be bovine contagious or environmental mastitis pathogens. Within the group of organisms considered contagious, we isolated Staphylococcus aureus and Mycoplasma arginini. This was the first time that a Mycoplasma species was isolated from houseflies. We identified 5 organisms considered foodborne pathogens that affect human health: Salmonella spp., Escherichia coli, Staph. aureus, Bacillus cereus, and Bacillus subtilis. Four of the organisms isolated in this study were also linked with milk spoilage, including Pseudomonas aeruginosa, Bacillus cereus, Bacillus licheniformis, and Paenibacillus lactis. This study confirmed that houseflies carry a high bacterial diversity, including organisms associated with animal infections, organisms that could be a concern for public health, or organisms that could negatively affect milk quality.

Changes in left atrial function in patients undergoing cardioversion for atrial fibrillation: relevance of left atrial strain in heart failure

Background

Left atrial (LA) reservoir strain provides prognostic information in patients with and without heart failure (HF), but might be altered by atrial fibrillation (AF). The aim of the current study was to investigate changes of LA deformation in patients undergoing cardioversion (CV) for first-time diagnosis of AF.

Methods and results

We performed 3D-echocardiography and strain analysis before CV (Baseline), after 25 ± 10 days (FU-1) and after 190 ± 20 days (FU-2). LA volumes, reservoir, conduit and active function were measured. In total, 51 patients were included of whom 35 were in SR at FU-1 (12 HF and preserved ejection fraction (HFpEF)), while 16 had ongoing recurrence of AF (9 HFpEF). LA maximum volume was unaffected by cardioversion (Baseline vs. FU-2: 41 ± 11 vs 40 ± 10 ml/m²; p = 0.85). Restored SR led to a significant increase in LA reservoir strain (Baseline vs FU-1: 12.9 ± 6.8 vs 24.6 ± 9.4, p < 0.0001), mediated by restored LA active strain (SR group Baseline vs. FU-1: 0 ± 0 vs. 12.3 ± 5.3%, p < 0.0001), while LA conduit strain remained unchanged (Baseline vs. FU-1: 12.9 ± 6.8 vs 13.1 ± 6.2, p = 0.78). Age-controlled LA active strain remained the only significant predictor of LA reservoir strain on multivariable analysis (β 1.2, CI 1.04–1.4, p < 0.0001). HFpEF patients exhibited a significant increase in LA active (8.2 ± 4.3 vs 12.2 ± 6.6%, p = 0.004) and reservoir strain (18.3 ± 5.7 vs. 22.8 ± 8.8, p = 0.04) between FU-1 and FU-2, associated with improved LV filling (r = 0.77, p = 0.005).

Conclusion

Reestablished SR improves LA reservoir strain by restoring LA active strain. Despite prolonged atrial stunning following CV, preserved SR might be of hemodynamic and prognostic benefit in HFpEF.

Graphical abstract

Mycoplasma species isolated from bovine milk collected from US dairy herds between 2016 and 2019

Determining the species of mycoplasma isolated from culture-positive milk samples is important for understanding the clinical significance of their detection. Between August 2016 and December 2019, 214,518 milk samples from 2,757 dairy herds were submitted to Quality Milk Production Services (QMPS) at Cornell University for mycoplasma culture. From these samples, 3,728 collected from 204 herds were culture positive. Based on the request of herd managers, owners, or veterinarians, 889 isolates from 98 herds were subjected to molecular identification by PCR and amplicon sequencing. The largest proportion of the identified isolates were from New York State (78.1%), while the others came from the eastern United States (17.8%), Texas (2.0%), and New Mexico (2.1%). As expected, Mycoplasma spp. were the most common (855 isolates, 96.2%) and Acholeplasma spp. accounted for the remainder (34 isolates, 3.8%). Mycoplasma bovis was the most prevalent Mycoplasma species (75.1%), followed by M. bovigenitalium (6.5%), M. canadense (5.9%), M. alkalescens (5%), M. arginini (1.7%), M. californicum (0.1%), and M. primatum (0.1%). A portion of the isolates were confirmed as Mycoplasma spp. other than M. bovis but were not identified at the species level (16 isolates, 1.8%) because further information was not requested by the manager, owner, or veterinarian. Mycoplasma bovis was the only species identified in 59 of the 98 herds. However, more than 1 Mycoplasma sp. was identified in 29 herds, suggesting that herd infection with 2 or more mycoplasmas is not uncommon. Moreover, a Mycoplasma sp. other than M. bovis was the only species identified in 8 herds. From the subset of 889 mycoplasma culture-positive isolates from 98 herds, we determined that over a third of the herds had either more than 1 Mycoplasma sp. or a Mycoplasma sp. other than M. bovis detected in their milk samples. In conclusion, we observed that M. bovis is the most common pathogenic Mycoplasma species found in mastitic milk, but other Mycoplasma species are not uncommon. Our results suggest that it is critical to test milk samples for mycoplasmas using diagnostic tests able to identify both the genus and the species.

Histological assessment of new bone formation with biomimetic scaffold in posterolateral lumbar spine fusion

Spinal fusion procedures often require the use of bone grafts (autograft or allograft) to help bone healing and to increase stability. However, the application of autografts is frequently limited by donor site morbidity. In recent years, different synthetic bone substitutes have been introduced in the clinical practice to overcome these limitations. The purpose of this paper is to report a case where a biomimetic, synthetic and osteoconductive bone graft substitute was successfully implanted in a patient during lumbar spine arthrodesis. The case of a 58-year-old female subjected to lumbar spine arthrodesis with bone augmentation is described. The bone graft substitute RegenOss® (Finceramica, Faenza, Italy) was implanted during spinal arthrodesis. The successful bone integration was evaluated by X-rays. After 11 months, the patient underwent a second surgery due to spine imbalance; the debris of the bone graft was therefore collected and analyzed by macroscopic evaluation and by histology. The bone substitute was successfully implanted during a spinal arthrodesis procedure. Histologic evaluation of the removed bone graft debris showed the complete resorption of the implant and the formation of new bone, which was well integrated with the host bone. This bone substitute may represent a safe and effective alternative to autologous bone grafts, avoiding adverse events related to donor-site morbidity.

Blood perfusion of teat tissue in dairy cows: Changes associated with pre-milking stimulation and machine milking

Mechanical forces during machine milking of dairy cows evoke circulatory impairment of the teat tissue that may affect the teats' defense mechanisms against mastitis pathogens. Ample research describes dimensional changes of different teat traits after machine milking, whereas reports that describe changes in blood circulation of dairy cows' teats are limited. Therefore, the objectives of this study were to (1) describe changes in teat blood circulation that occur after pre-milking teat stimulation and machine milking and (2) study the effect of 2 different milking liners on machine milking-induced changes in teat blood flow. In a randomized trial, Holstein dairy cows were stratified by parity, stage of lactation, and average daily milk yield during the previous week, and allocated to 1 of 2 treatment groups. Treatment consisted of 1 milking observation with either a round or multisided concave milking liner. Teat scans were taken of the left front and the right hind teats using power Doppler ultrasonography. Imaging occurred before pre-milking udder preparation (T1), after completion of pre-milking udder preparation but before milking-unit attachment (T2), and immediately after unit detachment (T3). Perfusion intensity measurements from teat scans were performed with a commercially available software program. Data from 109 cows were analyzed. A general linear mixed model showed differences in perfusion intensity between time points. Least squares means (95% confidence intervals) for T1, T2, and T3, respectively, were 0.035% (0.026-0.047), 0.124% (0.093-0.164), and 0.095% (0.073-0.124). Conversely, no statistically significant differences between treatment groups were observed. We conclude that teat blood circulation is subjected to several influences, including inherent circulatory regulation mechanisms, as well as extrinsic factors such as machine milking. Future research is warranted to decipher the magnitude of their influence and to further our understanding of how these changes relate to the susceptibility to intramammary infection and milking performance.

Validation of a mycoplasma molecular diagnostic test and distribution of mycoplasma species in bovine milk among New York State dairy farms

Mycoplasma mastitis is a contagious and costly disease of dairy cattle that significantly affects animal health and milk productivity. Mycoplasma bovis is the most prevalent and invasive agent of mycoplasma mastitis in dairy cattle, and early detection is critical. Other mycoplasma have been isolated from milk; however, the role and prevalence of these species as mastitis pathogens are poorly understood. Routine screening of milk for mycoplasma by bacteriological culture is an important component of a farm control strategy to minimize a herd mycoplasma outbreak, but phenotypic methods have limited ability to speciate mycoplasma, affecting how farms and practitioners can understand the role and effect of species other than M. bovis in herd health. Fastidious mycoplasma culture can be lengthy and inconclusive, resulting in delayed or false negative reports. We developed and validated a multitarget PCR assay that can in the same day confirm or reject a presumptive positive mycoplasma culture found upon bacteriological testing of clinical specimens, further discriminate between Acholeplasma and Mycoplasma, and identify M. bovis. Coupled with sequence analysis isolates can be further identified as bovine mycoplasma Mycoplasma arginini, Mycoplasma alkalescens, Mycoplasma canadense, Mycoplasma bovirhinis, Mycoplasma bovigenitalium, Mycoplasma californicum, Acholeplasma laidlawii, and Acholeplasma oculi. Assay validation included analysis of 845 mycoplasma representing these species and 30 additional bacterial species obtained from routine milk submissions to the Quality Milk Production Services from New York State farms and veterinary clinics between January 2012 and December 2015. Among 95 herds, we found 8 different Mycoplasma species and 3 different Acholeplasma species, with an overall prevalence of M. bovirhinis of 1%, A. oculi of 2%, M. arginini of 2%, M. californicum of 3%, M. canadense of 10%, M. bovigenitalium of 10%, A. laidlawii of 11%, M. alkalescens of 17%, and M. bovis of 78%. More than one mycoplasma was found in 14% of the herds tested, and both M. bovis and Acholeplasma were found in 6% of the farms. Incorporation of the validated molecular diagnostic assay into routine bacteriological screening as a supportive confirmation and identification tool will lead to an improved assessment of Mycoplasma and Acholeplasma prevalence data, which will facilitate increased knowledge about the role of these mycoplasma in mastitis.

Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Lactococcus lactis ssp. lactis and Lactococcus garvieae isolated from bovine intramammary infections

In total, 181 streptococci-like bacteria isolated from intramammary infections (IMI) were submitted by a veterinary clinic to Quality Milk Production Services (QMPS, Cornell University, Ithaca, NY). The isolates were characterized by sequence analysis, and 46 Lactococcus lactis ssp. lactis and 47 Lactococcus garvieae were tested for susceptibility to 17 antibiotics. No resistant strains were found for β-lactam antibiotics widely used in clinical practice (penicillin, ampicillin, and amoxicillin), and all minimum inhibitory concentrations (MIC) were far from the resistance breakpoints. Eight strains had MIC intermediate to cefazolin. The random amplification of polymorphic DNA (RAPD)-PCR fingerprint patterns showed a slightly higher heterogeneity for Lc. lactis ssp. lactis isolates than for Lc. garvieae isolates.

Immunophenotype-related microRNA expression in canine chronic lymphocytic leukemia

MicroRNAs (miRNAs) are posttranscriptional regulatory noncoding RNAs used to profile human hematopoietic tumors. In this study, some mature miRNAs was quantitated in peripheral blood from dogs with chronic lymphocytic leukemia (CLL). Relative expression data were normalised against four endogenous controls (let-7a, miR-17-5p, miR-26b, and miR-223) selected by geNorm analysis. The results revealed distinct miRNA patterns in CLL depending on the immunophenotype. Also in dogs, the different miRNAs expression could reflect developmental lineage and tumor differentiation. The similar genetics, physiology and exposure to environment in dogs and humans make the miRNA expression study in canine CLL attractive for comparative oncology.

Identification of suitable endogenous controls and differentially expressed microRNAs in canine fresh-frozen and FFPE lymphoma samples

The elucidation of microRNA (miRNA) expression pattern in canine lymphoma is attractive for veterinary and comparative oncology due to similar genetics, physiology and exposure to environment in dogs and humans. In this work, the expression of a panel of mature miRNAs was quantitated in fresh-frozen and formalin-fixed paraffin-embedded (FFPE) lymph nodes from canine lymphoma. The major findings were: the detection of a panel of miRNAs expressed in canine lymph node; the identification of three suitable endogenous controls (let-7a, miR-16, and miR-26b) by NormFinder and geNorm analysis; the concordance between results obtained from fresh-frozen and FFPE samples; the detection of upregulation of miR-17-5p and miR-181a in B- and T-cell lymphomas respectively. This is the first study aimed to the application of miRNAs analysis in canine lymphoma.

Atypical language in lesional and nonlesional complex partial epilepsy

OBJECTIVE

We investigated the relationship between partial epilepsy, MRI findings, and atypical language representation.

METHODS

A total of 102 patients (4 to 55 years) with left hemisphere epileptogenic zones were evaluated using three fMRI language tasks obtained at 1.5 or 3T with EPI BOLD techniques: verbal fluency, reading comprehension, and auditory comprehension. fMRI maps were visually interpreted at a standard threshold and rated as left or atypical language.

RESULTS

Atypical language dominance occurred in 30 patients (29%) and varied with MRI type (p < 0.01). Atypical language representation occurred in 36% (13/36) with normal MRI, 21% (6/29) with mesial temporal sclerosis, 14% (4/28) with focal cortical lesions (dysplasia, tumor, vascular malformation), and all (6/6) with a history of stroke. Multivariate logistic regression analysis found handedness, seizure onset, and MRI type accounted for much of the variance in language activation patterns (chi(2) = 24.09, p < 0.01). Atypical language was more prevalent in patients with early seizure onset (43.2%, p < 0.05) and atypical handedness (60%, p < 0.01). None of the three clinical factors were correlated with each other (p > 0.40). Patients with atypical language had lower verbal abilities (F = 6.96, p = 0.01) and a trend toward lower nonverbal abilities (F = 3.58, p = 0.06). There were no differences in rates of atypical language across time, age groups, or MRI scanner.

CONCLUSION

Early seizure onset and atypical handedness, as well as the location and nature of pathologic substrate, are important factors in language reorganization.

Fluctuating velocity and momentum transfer in dense granular flows

We show experimentally that in a free-surface granular flow the fluctuating velocity brings about momentum transfer at a considerable rate only very close to the free surface. Away from the free surface, where the flow is dense and stratified (or laminar), the fluctuating velocity plays no prominent dynamic role and stems passively from a kinematic constraint: The strata of particles must shake laterally as they slip past one another in the direction of the mean flow. Based on this insight, we formulate a simple model for the fluctuating velocity of dense granular flows. The predictions of the model agree well with our experimental measurements.

Turbulent friction in rough pipes and the energy spectrum of the phenomenological theory

The classical experiments on turbulent friction in rough pipes were performed by Nikuradse in the 1930s. Seventy years later, they continue to defy theory. Here we model Nikuradse's experiments using the phenomenological theory of Kolmogórov, a theory that is widely thought to be applicable only to highly idealized flows. Our results include both the empirical scalings of Blasius and Strickler and are otherwise in minute qualitative agreement with the experiments; they suggest that the phenomenological theory may be relevant to other flows of practical interest; and they unveil the existence of close ties between two milestones of experimental and theoretical turbulence.

Localized turbulent flows on scouring granular beds

In many applications a sustained, localized turbulent flow scours a cohesionless granular bed to form a pothole. Here we use similarity methods to derive a theoretical formula for the equilibrium depth of the pothole. Whereas the empirical formulas customarily used in applications contain numerous free exponents, the theoretical formula contains a single one, which we show can be determined via the phenomenological theory of turbulence. Our derivation affords insight into how a state of dynamic equilibrium is attained between a granular bed and a localized turbulent flow.

Radial segregation patterns in rotating granular mixtures: waviness selection

We model the radial segregation patterns that form in a thin rotating drum partially filled with beads of two sizes. We predict that the waviness (or amplitude-to-wavelength ratio, denoted w) of a pattern should be subjected to low-pass filtering with a cutoff waviness w(c) that depends strongly on the fill level of the drum. Then we perform experiments and find that w</=w(c) for all patterns, in accord with our prediction. We also find that w=w(c) for (and only for) steady patterns, and conclude that the waviness of a steady pattern is selected by the low-pass filtering.

Structure and kinematics in dense free-surface granular flow

We show that the structure of a dense, free-surface boundary layer granular flow is similar to the structure of a laminar liquid flow: There is a strong component of order (stratification parallel to the mean flow) superposed with a mild component of disorder (self-diffusion perpendicular to the mean flow). We also show that the self-diffusion coefficient scales with the mean velocity and propose a model that relates this scaling to the ordered structure of the flow. Last, we show that the structure of the flow imprints an oscillatory signature (similar to that found in confined granular flow) on the mean velocity profile.

Two-phase densification of cohesive granular aggregates

When poured into a container, cohesive granular materials form low-density, open granular aggregates. If pressure is applied to these aggregates, they densify by particle rearrangement. Here we introduce experimental and computational results suggesting that densification by particle rearrangement occurs in the form of a phase transition between two configurational phases of the aggregate. Then we show that the energy landscape associated with particle rearrangement is nonconvex and therefore consistent with our interpretation of the experimental and computational results. Our conclusions are relevant to many technological processes and natural phenomena.

Scaling and similarity in rough channel flows

We show that Manning's empirical formula for the mean velocity of turbulent flows in channels represents the power-law asymptotic behavior of a flow of incomplete similarity in the relative roughness. We then derive the formula based on the phenomenological theory of turbulence. Our derivation yields the correct similarity exponent; it justifies Manning's use of a single parameter, the hydraulic radius, to characterize the geometry of the cross section; and it affords insight into the mechanism of momentum transfer.

[Statins: from hypocholesteremic drugs to antiatherogenic agents]

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) are widely used for the treatment of hypercholesterolemia. They reduce LDL levels more than other lipid-lowering drugs. Moreover, they are effective in raising HDL and even in reducing triglyceride levels. Statins have an excellent tolerability and safety. Clinical trials in patients with and without ischemic heart disease and with and without high cholesterol levels have demonstrated that statins significantly reduce the relative risk of major coronary events and of total mortality. Other mechanisms independent of LDL lowering may play an important role in the clinical benefits conferred by these drugs and may broaden their therapeutic indications from lipid-lowering to antiatherogenic agents.

Coronary rotational atherectomy via transradial approach: a study using radial artery intravascular ultrasound

The use of coronary rotational atherectomy via radial artery (RA) has been limited because of the large diameter of guiding catheters. We studied the feasibility of this approach by sizing the RA by intravascular ultrasound (IVUS) and using 7 Fr (2.31 mm) guiding catheters. Seventeen transradial percutaneous transluminal coronary rotational atherectomy (PTCRA) procedures were performed in 16 patients, mean age 62 +/- 12 years, for a total of 19 vessels treated. The mean RA diameter was 2.9 +/- 0.36 mm and the mean reference diameter of the treated coronary vessels was 2.7 +/- 0.45 mm. The mean coronary percent stenosis was 74% +/- 10%, the mean minimum lumen diameter was 0.76 +/- 0.35 mm, and the mean lesion length was 16 +/- 19 mm. Ten vessels were treated with rotational atherectomy alone, or with adjunctive high pressure balloon angioplasty, achieving an acute lumen gain of 0.8 +/- 0.4 mm (P = 0. 001). Nine arteries had stent implantation in addition to rotational atherectomy, resulting in an acute lumen gain of 2.4 +/- 0.5 mm (P = 0.001). The success rate was 94%. There were no vascular complications. Two patients had a non-Q myocardial infarction. In conclusion, transradial PTCRA when used in conjunction with IVUS of the RA is a safe and feasible procedure in selected cases. This may be an alternative approach of revascularization technique especially for patients with limited vascular access and for those who require early ambulation or early discharge from the hospital.

Surgical treatment of far lateral lumbar disc herniation. Identification of compressed root and discectomy by lateral approach

STUDY DESIGN

A new method is described of compressed root identification and discectomy for extraforaminal disc herniation, by a lateral intertransversalis approach.

OBJECTIVES

To describe a safe surgical approach that does not require resection of adjacent bone structures during extraforaminal discectomy.

SUMMARY OF BACKGROUND DATA

Most earlier series have reported approaches that damaged bordering bone structures with wide laminoarthrectomy. This is an attempt at a safer, simpler surgical approach.

METHODS

Thirteen patients with lateral hernia have undergone this surgical procedure since 1995. Herniectomy was performed after identification of the compressed root within the iliopsoas muscle.

RESULTS

All the patients resumed the upright position with the aid of semirigid brace 24 hours after surgery. Upon awakening from the anesthesia, no patient reported peripheral pain. Motor deficits resolved after physical rehabilitation in all but one patient. At a mean follow-up of 14 months, there was no report of back pain.

CONCLUSION

The procedure described in this article offers a simple alternative to the valid procedures presently at hand. It offers the advantage of no bone resection and of minimizing nerve structures manipulation.

Postlaminectomy cervical dislocation in von Recklinghausen's disease. A case report

STUDY DESIGN

A case of a 9-year-old girl with von Recklinghausen's disease who has acute tetraparesis caused by a complete dislocation of C6-C7 after a cervical laminectomy performed at another hospital.

OBJECTIVES

To demonstrate the treatment difficulties of cervical spine abnormality associated with neurofibromatosis.

SUMMARY OF BACKGROUND DATA

Craig and Govender have reported cases of neurofibromatosis of the cervical spine (1992).

METHODS

The patient underwent emergency surgery starting with a posterior release of the articular facets and with the positioning of two Roy-Camille plates. The dislocation of C6-C7 was reduced by an anterior approach. Finally the Roy-Camille plates were removed, a plate was implanted posteriorly at the C6 and C7 joints, and a posterior cable was positioned around the C2-C3 posterior arches.

RESULTS

More than 4.5 years after surgery, the patient's neurologic condition remains satisfactory. She can walk and run and has no sphincter disorders.

CONCLUSIONS

The results underline the importance of simultaneous anterior and posterior surgical approaches in this disease.

A cost-effective sestamibi protocol in the managed health care era

BACKGROUND

In the managed health care era a need exists to lower the cost of diagnostic tests for coronary artery disease. One possible approach is to eliminate the rest study in the conventional stress-rest perfusion imaging protocol with single photon emission computed tomography.

OBJECTIVE

The aim of the study was to determine the frequency with which single stress single photon emission computed tomography acquisition can be used to diagnose disease in normal patients compared with dual stress-rest protocol.

STUDY GROUP

Two hundred patients without history of myocardial infarction, coronary revascularization, valvular disease, dilated cardiomyopathy, or left bundle branch block undergoing 1-day (n = 86) or 2-day (n = 114) stress-rest sestamibi imaging were studied. The stress was exercise in 147 patients and pharmacologic in 53 patients.

RESULTS

On the basis of the stress study, 112 patients had normal images, and 88 patients had abnormal images. On the basis of the combined stress-rest images, 131 patients had normal images, and 69 patients had abnormal images (agreement 85%, kappa 0.68 +/- 0.05). Only 6 (5%) of the 112 patients with normal images based on the stress images were considered to have abnormal images by the combined stress and rest images.

CONCLUSIONS

In patients with normal stress images elimination of the rest study rarely alters interpretation. Rest studies are most useful in patients with abnormal or equivocal stress images. Such selective elimination of the rest studies may decrease the cost of nuclear procedures and should be considered in the current managed care health system.

Prediction of outcome of patients with life-threatening ventricular arrhythmias treated with automatic implantable cardioverter-defibrillators using SPECT perfusion imaging

BACKGROUND

In the present study, we examined the predictors of outcome of 103 patients with coronary artery disease and left ventricular dysfunction who had life-threatening ventricular arrhythmias and were treated with implantable cardioverter-defibrillators with the use of single-photon emission computed tomography (SPECT).

METHODS AND RESULTS

During a mean follow-up of 29 months, there were 29 cardiac deaths. In comparison with patients who died, survivors had less diabetes mellitus (45% versus 19%, P < .007), higher left ventricular ejection fraction (23 +/- 9% versus 27 +/- 11%, P = .04), and fewer perfusion defects as determined with stress SPECT (15 +/- 5 versus 12 +/- 5, P < .004). Most of the perfusion defects were fixed, indicative of scarring; the extent of reversible defects did not differ (2 +/- 3 in survivors and 3 +/- 4 in nonsurvivors). Multivariate Cox survival analysis identified the number of fixed defects as the only independent predictor of death (chi 2 = 10, P = .002). There were six deaths among 42 patients (14%) with < 8 fixed defects compared with 23 deaths among 61 patients (38%) with > or = 8 defects (P = .005). The 4-year survival was better in patients with < 8 segmental fixed defects than in those with > or = 8 fixed defects (80% versus 36%) (chi 2 = 8, P = .005).

CONCLUSIONS

The myocardial perfusion pattern is an important determinant of outcome in patients with life-threatening ventricular arrhythmias who are treated with a implantable cardioverter-defibrillator. The extent of scarring separates patients into high- and low-risk groups with a 2.7-fold difference in death rate.

Prognostic value of tomographic rest-redistribution thallium 201 imaging in medically treated patients with coronary artery disease and left ventricular dysfunction

BACKGROUND

Previous studies show that rest-redistribution thallium imaging is useful in the assessment of myocardial viability. The impact of such studies on patient outcome is not well defined. This study examined the prognostic value of tomographic rest-redistribution 201T1 imaging in 81 medically treated patients with coronary artery disease and left ventricular dysfunction.

METHODS AND RESULTS

Rest-redistribution single-photon emission computed tomographic images were obtained and analyzed quantitatively. The segmental thallium uptake (20 segments per patient) was interpreted as normal, reversible defect, mild to moderate fixed defect, or severe fixed defect. The thallium images were abnormal in 80 patients, with no redistribution (no ischemia) in 43 patients and redistribution (ischemia) in 38 patients. The left ventricular ejection fraction was 27% +/- 8% in patients with no redistribution and 26% +/- 7% in patients with redistribution (difference not significant). In patients with no ischemia, there were 7 +/- 5 severe fixed defects and 5 +/- 4 mild to moderate fixed defects per patient. In patients with ischemia there were 7 +/- 4 reversible defects, 3 +/- 3 mild to moderate fixed defects, and 5 +/- 4 severe fixed defects per patient. The number of any abnormal segments was 11 +/- 5 in patients with no ischemia and 14 +/- 4 in patients with ischemia (p = 0.03). During a mean follow-up of 31 +/- 24 months, there were 11 cardiac deaths in patients with no ischemia (26%) and 22 in patients with ischemia (58%); the survival rate was worse in patients with than without ischemia (p < 0.05). Multivariate Cox survival analysis on important clinical, angiographic, and thallium variables showed that the presence of redistribution was an independent predictor of death (x2 = 5; p = 0.03).

CONCLUSIONS

Patients with left ventricular dysfunction and redistribution on rest thallium imaging, a marker of hibernating myocardium, have a higher mortality rate with medical therapy than do patients with a comparable degree of left ventricular dysfunction but with fixed defects only. Thus observations similar to those made with positron emission tomography can be made in a much more straightforward, simple, and probably cost-effective manner with single-photon emission computed tomography.

Use of a tantalum-178 generator and a multiwire gamma camera to study the effect of the Mueller maneuver on left ventricular performance: comparison to hemodynamics and single photon emission computed tomography perfusion patterns

During the Mueller maneuver, there is a decrease in intrathoracic pressure and an increase in transmural left ventricular pressure. The changes in loading conditions cause transient left ventricular dysfunction. This study examined the effects of the Mueller maneuver on left ventricular performance using tantalum (Ta)-178 (half-life 9.3 min) and a multiwire gamma camera. First-pass radionuclide angiograms were obtained at baseline and during Mueller maneuver in 41 patients aged 58 +/- 10 years. In 34 patients, stress single photon emission computed tomography (SPECT) myocardial perfusion imaging with thallium-201 or sestamibi was also performed. Hemodynamic measurements during the Mueller maneuver (n = 10) showed a decrease in systemic pressure (139 +/- 25 mm Hg vs 123 +/- 24 mm Hg, p < 0.001) and pulmonary artery pressure (24 +/- 6 mm Hg vs 14 +/- 12 mm Hg, p = 0.01) and an increase in heart rate (67 +/- 10 bpm vs 75 +/- 14 beats/min, p = 0.001). Among the 34 patients who had perfusion imaging, the left ventricular ejection fraction remained unchanged or increased in 17 patients (group 1) (48% +/- 19% vs 49% +/- 21%, p not significant) and decreased (> or = 5%) in 17 patients (group 2) (55% +/- 13% vs 40% +/- 16%, p = 0.001). The stress SPECT images showed no or only fixed defects in 11 (65%) patients in group 1 and 3 (18%) patients in group 2 (p = 0.02), and reversible defects in 6 (35%) patients in group 1 and 14 (82%) patients in group 2 (p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Prognostic value of rest-redistribution tomographic thallium-201 imaging in ischemic cardiomyopathy

The relation between the presence of viable myocardium by rest-redistribution thallium imaging and prognosis is not well defined. This study examined the prognostic value of rest-redistribution single-photon emission computed tomographic imaging with thallium-201 in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction. Patients were divided into 2 groups: group 1 patients (n = 47) were treated medically and group 2 patients (n = 38) underwent coronary revascularization. The 2 groups were comparable in the extent of CAD and in LV ejection fraction. Thallium images showed normal tracer uptake in 1 group 1 and 3 group 2 patients, fixed defects in 26 group 1 and 18 group 2 patients, and both reversible and fixed defects in 20 group 1 and 17 group 2 patients (p = NS). Based on analysis of 20 segments/patient, reversible defects were seen in 4 +/- 4 segments/patient in group 1 and 5 +/- 5 segments/patient in group 2 (p = NS). Viable myocardium (defined as normal tracer uptake, reversible defects, or mild fixed defects) was seen in 14 +/- 4 segments/patient in group 1 and 15 +/- 5 segments/patient in group 2 (p = NS). During a mean follow-up of 31 months, there were 16 group 1 (34%) and 6 group 2 (16%) deaths. The annual mortality rate was 13% in group 1 and 6% in group 2. Actuarial survival analysis showed better survival in group 2 than in group 1 (p = 0.056). Thus, viable myocardium in patients with CAD and LV dysfunction is associated with poor prognosis with medical therapy. Coronary revascularization improves prognosis.

Sex differences in cognitive processing in children treated with CNS prophylaxis for acute lymphoblastic leukemia

Evaluated cognitive processing in 51 children (27 female, 24 male) who had been treated for acute lymphoblastic leukemia (ALL) with CNS prophylaxis (cranial radiation in combination with intrathecal chemotherapy) and were continuously disease-free for 5 to 12 years. The control group comprised 15 children treated for Wilm's tumor. Functions assessed included visuoperceptual skills, generation of organizational strategies, sensitivity to organizational structure, and attention. The ALL group showed performance deficits relative to the solid tumor controls in appreciating the organization inherent in complex visuospatial material and alertness, with females more severely affected than males. Sex differences favoring males on IQ and academic achievement were related to these cognitive processes.

Prevalence of non-specific vaginitis and correlation with isolation of Gardnerella vaginalis in Italian outpatients

Among all subjects attending a Center for prevention of female genital tract cancer Gardnerella vaginalis was isolated from 57 out of 171 women affected by non-specific vaginitis (NSV), from 15 of 703 non-NSV vaginitis patients and from 10 of 338 healthy adults. Postmenopausal women showed an increased rate of asymptomatic carriage of G. vaginalis. The data suggest a relatively weak association between clinical diagnosis of NSV and isolation of G. vaginalis.

[Normal echo-Doppler values in Duromedics valvular prostheses]

To determine the value of Doppler echocardiography in the normal clinical use of functional diagnosis, and to define normal values of prosthetic mitral and aortic valves, of different sizes and in different positions, 48 patients (53 Duromedics prosthesis) were examined. Two groups were formed: the first group (12 patients) was studied soon after operation, i.e. less than 3 weeks; the second group (36 patients) was examined at a later stage i.e. 2-60 months later. This group did not present any associated valvular disease (i.e. there was no aortic disease in patients with mitral prostheses nor mitral disease in patients with aortic prostheses). In the first group the following results were found: DP max = 12.70 +/- 4 mmHg, DP mean = 4.0 +/- 3 mmHg, Half Time Pressure (T 1/2) = 79.57 +/- 17 ms in mitral prostheses; DP max = 25 +/- 10.9 mmHg, DP mean = 6.8 +/- 4 mmHg in aortic prostheses. In the second group the findings were as follows: mitral prostheses: DP max = 9.28 +/- 3.32 mmHg, DP mean = 3.0 +/- 1.0 mmHg, T 1/2 = 80 +/- 17.96 ms; aortic prostheses: DP max = 19.0 +/- 9.59 mmHg, DP mean = 6.0 +/- 3 mmHg. A trend towards higher DP values was noted in the first group of mitral prostheses (p = 0.05 only for DP max; for DP mean no statistic significance). No differences were noted either between the first and second group as regards aortic prostheses. For prosthetic mitral valves permissible upper limits of DP max, DP mean and T 1/2 in the first and second groups were respectively: 16.70 mmHg, 7.0 mmHg, 96.57 ms; and 12.26 mmHg, 4.0 mmHg, 105.96 ms.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of adolescent scoliosis by the Cotrel-Dubousset method

The new Cotrel-Dubousset segmental instrumentation systems allows the surgeon to correct scoliotic deformity in all three planes as well as providing such solid fixation that the use of external postoperative immobilisation is eliminated. The authors discuss the main theoretical concepts as well as its method of application.

Simplified identification of bacteria belonging to the genus Salmonella

A new, simplified procedure for identification of bacteria belonging to the genus Salmonella is reported. By this procedure which is a new combination of well know tests, Salmonella spp. are easily and reproducibly differentiated from non Salmonella spp. after 6 h of incubation at 37 degrees C.

[Frequency and antibiotic resistance of bacteria isolated from urine cultures]

The AA report the data pertinent to the urine culture performed during a year in the Sanitary and Prophylactic Laboratory of the district of L'Aquila. In urine samples with number of bacteria > 10(5)/ml have been found E. coli (49%), Proteus mirabilis (32%), Pseudomonas aeruginosa (12%), Staphylococcus aureus (5%), Proteus rettgeri (1%), Enterococco (1%). The data are also reported concerning germ resistance to several antibiotics.