Effect of gender on the reliability of COVID-19 rapid antigen test among elderly

Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers.     

Heart failure in hypertensive patients with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is supposed to be a useful marker of cardiovascular complications during the course of hypertension. Authors compared the presence of heart failure, left ventricular diastolic dysfunction and chronic atrial fibrillation in hypertensive patients with and without left ventricular hypertrophy defined by echocardiography. Hospital records of 192 hypertensives treated in our medical department during years 1996-1999 were analysed. Left ventricular hypertrophy was defined by echocardiography (Penn convention) as left ventricular mass index > 134 g/m2 in men and > 110 g/m2 in women. Presence of LVH was found in 128 patients (mean age 65.9 years), absence of LVH in 64 patients (mean age 64.8 years). Both groups of hypertensives were matched by demographic parameters, by the presence of hyperlipidemia, by smoking habits. Hypertensive patients with left ventricular hypertrophy were more often treated by ACE inhibitors. There were statistically significant more patients with heart failure, left ventricular diastolic dysfunction and chronic atrial fibrillation in LVH-positive patients than in LVH-negative once. There was also statistically significant lower ejection fraction (50.3 +/- 11.4% vs 56.5 +/- 7.4%) in LVH-positive patients than in LVH-negative once. Left ventricular hypertrophy in patients with hypertension brings usually a complicated course of the disease with a high contribution to the development of chronic heart failure.     

Laparoscopic Colorectal Surgery for Obese Patients: Decreased Conversions with the Hand-Assisted Technique

Background

Laparoscopic surgery benefits obese patients but technical difficulties associated with suboptimal exposure and access in these subjects may prompt conversion to open surgery. Hand-assisted laparoscopic surgery (HALS) confers advantages over standard laparoscopy (LAP) by facilitating tactile feedback, assisted dissection, and retraction. These benefits could be particularly valuable in obese patients, allowing completion of difficult laparoscopic procedures in this subgroup. Our aim was to compare intra-operative and post-operative outcomes of HALS and LAP approaches in obese patients undergoing colorectal resection at our institution.

Methods

A retrospective study of a prospectively maintained laparoscopic colorectal surgery database was performed. HALS and LAP cases performed in obese patients (body mass index (BMI)?>30) were identified and compared for the following outcomes: operative time, intra-operative complications, rate of conversion to open, blood loss, length of stay, post-operative morbidity, and mortality. Outcomes for the converted patients were included on an intention-to-treat basis for all primary analyses. A secondary analysis of nonconverted and converted cases was also performed.

Results

Over a 5-year period, 496 obese patients underwent laparoscopic colorectal resection; 86 HALS and 410 LAP cases. The two groups were comparable in terms of age, gender, BMI, and indications for surgery. Conversion to open surgery was less often necessary in HALS compared to LAP cases (3.5 % vs. 12.7 %, p?=?0.014). The LAP group had a significantly smaller incision length for specimen extraction (HALS (7.0?±?1.3 cm) vs. LAP (5.7?±?2.1 cm), p?<?0.001). Length of stay, operative time, morbidity, and mortality rates were comparable between the two groups.

Conclusion

In obese patients who require colectomy, the HALS approach increases the likelihood of a successful minimally invasive operation. At the cost of a clinically negligible increase in incision length, HALS may save a high-risk group conversion to formal laparotomy and the adverse outcomes related to this.     

Bedside score predicting retained common bile duct stone in acute biliary pancreatitis

BACKGROUND Retained common bile duct(CBD) stone after an acute episode of biliary pancreatitis is of paramount importance since stone extraction is mandatory.AIM To generate a simple non-invasive score to predict the presence of CBD stone in patients with biliary pancreatitis.METHODS We performed a retrospective study including patients with a diagnosis of biliary pancreatitis. One hundred and fifty-four patients were included. Thirty-three patients(21.5%) were diagnosed with CBD stone by endoscopic ultrasound(US).RESULTS In univariate analysis, age(OR: 1.048, P = 0.0004), aspartate transaminase(OR:1.002, P = 0.0015), alkaline phosphatase(OR: 1.005, P = 0.0005), gamma-glutamyl transferase(OR: 1.003, P = 0.0002) and CBD width by US(OR: 1.187, P = 0.0445)were associated with CBD stone. In multivariate analysis, three parameters were identified to predict CBD stone;age(OR: 1.062, P = 0.0005), gamma-glutamyl transferase level(OR: 1.003, P = 0.0003) and dilated CBD(OR: 3.685, P = 0.027),with area under the curve of 0.8433. We developed a diagnostic score that included the three significant parameters on multivariate analysis, with assignment of weights for each variable according to the co-efficient estimate. A score that ranges from 51.28 to 73.7 has a very high specificity(90%-100%) for CBD stones, while a low score that ranges from 9.16 to 41.04 has a high sensitivity(82%-100%). By performing internal validation, the negative predictive value of the low score group was 93%.CONCLUSION We recommend incorporating this score as an aid for stratifying patients with acute biliary pancreatitis into low or high probability for the presence of CBD stone.     

Renal oxidative stress following CO2 pneumoperitoneum-like conditions

Background  Physiologic renal changes associated with pneumoperitoneum (PNP) have been described and various underlying mechanisms have been suggested. We investigated the possibility that PNP-associated renal damage is pressure dependent, and that oxidative stress is thereby involved. Materials and methods  Seventy Wistar rat kidneys (n = 10 per group) were isolated. They were perfused with oxygenated, warm, Krebs–Henseleit solution containing 5% albumin within an isolated environment and subjected to various CO₂ pressures (0 [control], 3, 5, 8, 12, 15, and 18 mmHg) for 60 min. Half of each group was additionally perfused for 30 min at 0 mmHg pressure. Results  Renal flow decreased proportionately to the applied pressure as did urine output: both decreased (P < 0.05) after 60 and 90 min when pressure ≥8 mmHg was applied. Oxygen extraction decreased (P < 0.05) during PNP in all pressurized groups. Xanthine oxidase (XO) activity and reduced glutathione in the tissues increased (P < 0.05) proportionately to pressures ≥8 mmHg. All parameters slightly reversed toward baseline values, upon the release of the intra-chamber pressure, except for the 18 mmHg group’s values. Conclusions  CO₂-PNP pressure induces kidney injury, possibly reversible immediately after pressure is annulled. Pressure is associated with oxidative stress, which interferes with cellular metabolism and function, possibly via an ischemic-reperfusion-like mechanism. This paper was presented in part in the 15th EAES, July 2007, Athens, Greece.     

Enhanced inertial focusing of microparticles and cells by integrating trapezoidal microchambers in spiral microfluidic channels

In this work, manipulating width and equilibrium position of fluorescent microparticles in spiral microchannel fractionation devices by embedding microchambers along the last turn of a spiral is reported. Microchambers with different shapes and sizes were tested at Reynolds numbers between 15.7 and 156.6 (100–1000 μL min⁻¹) to observe focusing of 2, 5 and 10 μm fluorescent microparticles. This paper also discusses the fabrication process of the microfluidic chips with femtosecond laser ablation on glass wafers, as well as a particle imaging velocimetry (μPIV) study of microparticle trajectories inside a microchamber. It could be demonstrated with an improved final design with inclined microchamber side walls, that the 2 μm particle equilibrium position is shifted towards the inner wall by ∼27 μm and the focusing line''s width is reduced by ∼18 μm. Finally, Saccharomyces cerevisiae yeast cells were tested in the final chip and a cell focusing efficiency of 99.1% is achieved.

In this work, manipulating width and equilibrium position of fluorescent microparticles in spiral microchannel fractionation devices by embedding microchambers along the last turn of a spiral is reported.