Fecal microbiota composition is related to brown adipose tissue 18F-fluorodeoxyglucose uptake in young adults

OBJECTIVE

Human brown adipose tissue (BAT) has gained considerable attention as a potential therapeutic target for obesity and its related cardiometabolic diseases; however, whether the gut microbiota might be an efficient stimulus to activate BAT metabolism remains to be ascertained. We aimed to investigate the association of fecal microbiota composition with BAT volume and activity and mean radiodensity in young adults.

METHODS

82 young adults (58 women, 21.8 ± 2.2 years old) participated in this cross-sectional study. DNA was extracted from fecal samples and 16S rRNA sequencing was performed to analyse the fecal microbiota composition. BAT was determined via a static ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography-computed tomography scan (PET/CT) after a 2 h personalized cooling protocol. ¹⁸F-FDG uptake was also quantified in white adipose tissue (WAT) and skeletal muscles.

RESULTS

The relative abundance of Akkermansia, Lachnospiraceae sp. and Ruminococcus genera was negatively correlated with BAT volume, BAT SUVmean and BAT SUVpeak (all rho ≤ - 0.232, P ≤ 0.027), whereas the relative abundance of Bifidobacterium genus was positively correlated with BAT SUVmean and BAT SUVpeak (all rho ≥ 0.262, P ≤ 0.012). On the other hand, the relative abundance of Sutterellaceae and Bifidobacteriaceae families was positively correlated with ¹⁸F-FDG uptake by WAT and skeletal muscles (all rho ≥ 0.213, P ≤ 0.042). All the analyses were adjusted for the PET/CT scan date as a proxy of seasonality.

CONCLUSION

Our results suggest that fecal microbiota composition is involved in the regulation of BAT and glucose uptake by other tissues in young adults. Further studies are needed to confirm these findings.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov no. NCT02365129 (registered 18 February 2015).

Immunoscintigraphy with 131I or 111In Labelled OC 125 F(ab')2 Fragments in Patients with Ovarian Carcinoma

To evaluate the clinical usefulness of immunoscintigraphy with OC 125 in ovarian carcinoma, we studied 25 patients suspected of having ovarian carcinoma or in follow-up after surgery. Fourteen patients were studied with 131I-OC 125 F(ab')2 and 11 with 111In-OC 125 F(ab')2. No differences were observed with the use of either radionuclide.

Global diagnostic indexes obtained were S = 100%, Sp = 44,5% and A = 81%. The low specificity obtained was remarkable: 5 false positive results in two uterine myomas, one abscess, one follicular cyst and one granulation tissue scar. On the other hand, all lesions of ovarian carcinoma were detected. Analysis of the evolution of tumor/background (T/B) uptake ratios from the first to the second day of exploration revealed a tendency for the ratio to diminish significantly (> 15%) in false positive cases with the exception of the abscess while this did not happen in true positive cases, with the exception of a regional recurrence. Analysis of T/B ratio variations could contribute towards elevating the test's specificity.

Orthodontic camouflage versus orthognathic surgery for class III deformity: comparative cephalometric analysis

The objective of this study was to compare different cephalometric variables in adult patients with class III malocclusions before and after treatment, in order to determine which variables are indicative of orthodontic camouflage or orthognathic surgery. The cases of 156 adult patients were assessed: 77 treated with orthodontic camouflage and 79 treated with orthodontics and orthognathic surgery. The following cephalometric variables were measured on pre-treatment (T1) and post-treatment (T2) lateral cephalograms: sella-nasion-A-point (SNA), sella-nasion-B-point (SNB), and A-point-nasion-B-point (ANB) angles, Wits appraisal, facial axis angle, mandibular plane angle, upper and lower incisor inclination, and inter-incisal angle. There were statistically significant differences in cephalometric variables before and after treatment between the two groups. The percentage of normal pre-treatment measurements in the camouflage orthodontics group was 30.7%, which worsened slightly to 28.4% post-treatment. However in the group receiving surgery, this was 24.5% pre-treatment, improving to 33.5% after surgery. SNA, SNB, Wits appraisal, lower incisor inclination, and inter-incisal angle showed differences between the two groups before and after treatment. Wits appraisal, lower incisor inclination, and inter-incisal angle were indicative of one or other treatment. Upper and lower incisor decompensation in both groups did not reach ideal values, which impeded complete skeletal correction in 52% of surgical cases.

Influence of the microstructure on electrochemical corrosion and nickel release in NiTi orthodontic archwires

The aim of this work was to determine the influence of the present phases and the chemical composition on the corrosion behavior and the nickel ion release of the NiTi orthodontic archwires. Eight Ni-Ti archwires from six commercial brands, in the as-received condition, were studied. The chemical composition, roughness, microstructure and the proportion of the phases as well as the corrosion behavior were analyzed for each archwire. The nickel ion release was characterized in artificial saliva immersion settings ranging up to 4 weeks. The results show that the presence of the martensitic phase improves corrosion resistance and significantly decreases Ni release into exterior medium in comparison with the austenitic specimens. In spite of the partial loss of superelasticity produced in the martensitic phase, it could be of great interest for biomedical applications, as it could minimize sensitization and allergies and improve biocompatibility and corrosion resistance of NiTi shape memory alloys.

Friction coefficients and wear rates of different orthodontic archwires in artificial saliva

The aim of this paper is to analyze the influence of the nature of the orthodontic archwires on the friction coefficient and wear rate against materials used commonly as brackets (Ti-6Al-4V and 316L Stainless Steel). The materials selected as orthodontic archwires were ASI304 stainless steel, NiTi, Ti, TiMo and NiTiCu. The array archwire's materials selected presented very similar roughness but different hardness. Materials were chosen from lower and higher hardness degrees than that of the brackets. Wear tests were carried out at in artificial saliva at 37 °C. Results show a linear relationship between the hardness of the materials and the friction coefficients. The material that showed lower wear rate was the ASI304 stainless steel. To prevent wear, the wire and the brackets have high hardness values and in the same order of magnitude.

Corrosion and corrosion-fatigue behavior of cp-Ti and Ti-6Al-4V laser-marked biomaterials

The aim of this work was to determine the influence of laser surface modification treatments on mechanical and electrochemical behavior in Ti and Ti-6Al-4V implants. For each metal, different samples were laser modified simulating the markings according to the international requirements. (It is necessary in each metallic biomaterial to mark the serial, batch and company numbers.) Microstructural changes produced by this treatment were observed: (a) the melting zone with small grain sizes and martensitic structures in above-mentioned metals and (b) the heat-affected zone (HAZ) with alpha phase in cp-Titanium with bigger grain sizes and Widmanstatten structure in Ti-6Al-4V. Positive tensile residual stress was determined by means X-ray analysis in the zones marked by laser. Furthermore, corrosion behavior was studied in a simulated body fluid at 37°C. Pitting was observed in different zones near the HAZ and the results showed a decrease of the corrosion resistance in the laser treated samples. Residual stresses and the martensitic microstructures favoured the decrease of the corrosion-fatigue life around 20% of both metals under physiological conditions.

Reduction of Ni release and improvement of the friction behaviour of NiTi orthodontic archwires by oxidation treatments

This work studies NiTi orthodontic archwires that have been treated using a new oxidation treatment for obtaining Ni-free surfaces. The titanium oxide on the surface significantly improves corrosion resistance and decreases nickel ion release, while barely affecting transformation temperatures. This oxidation treatment avoids the allergic reactions or toxicity in the surrounding tissues produced by the chemical degradation of the NiTi. In the other hand, the lack of low friction coefficient for the NiTi superelastic archwires makes difficult the optimal use of these materials in Orthodontic applications. In this study, the decrease of this friction coefficient has been achieved by means of oxidation treatment. Transformation temperatures, friction coefficient and ion release have been determined.

[Scintigraphy with thallium chloride in a case of clear cell sarcoma of the tendons and aponeurosis]

Clear cell sarcoma of the soft parts (CCSSP) is a rare and highly malignant tumor. This is a case report of a 31 years old woman who presented with a tumor in the internal face of left thigh. The tumor biopsy was suggestive of a possible malignant tumor of the peripheral nerve sheath (malignant schwannoma). Biochemical analyses, computed tomography and magnetic resonance were performed and reported a sarcoma of soft parts (CCSSP) without abnormal inguinal lymph nodes. With this diagnostic suspicion, the patient was sent to the Nuclear Medicine Service of our center where a 201Thallium scintigraphy study was performed. In this study, it showed the primary tumor together with a hot spot in the homolateral inguinal region, suggestive of the presence of a metastastic lymph node. This finding would change the surgical attitude in the patient, including inguinal lymphadenectomy. The post-surgical histological study confirmed a clear cell sarcoma of soft parts (CCSSP) with a metastatic inguinal lymph node.

Calculation of airborne radioactivity in a Technegas lung ventilation unit

Airborne contamination by 99Tcm has been monitored in the Nuclear Medicine Department in our hospital to assess the risk of internal contamination to occupational workers exposed to Technegas studies. An air sampler fitted with a membrane filter was used. The optimum time for air absorption for obtaining the maximum activity in the filter was calculated. Maximum activity in the membrane filter ensures minimum uncertainty, which is especially important when low-level activities are being measured. The optimum time depends on air absorption velocity, room volume and filter efficiency for isotope collection. It tends to 1/lambda (lambda = disintegration constant for 99Tcm) for large volume and low velocity. Room activity with the air pump switched on was related to filter activity, and its variation with time was studied. Free activity in air for each study was approximately 7 x 10(-4) the activity used, and the effective half-life of the isotope in the room was 13.9 min (decay and diffusion). For a typical study (630 MBq), the effective dose to staff was 0.01 microSv when in the room for 10 min.

Changes in the upper airway of patients who wear a modified functional appliance to treat obstructive sleep apnea

This study was designed to investigate changes that occur in the upper airway of patients with obstructive sleep apnea who use a modified functional appliance. The experimental group included 10 men, all diagnosed with obstructive sleep apnea. Nuclear magnetic resonance imaging was carried out on each patient. One image was taken when the patient was in maximum habitual occlusion and another was taken while the patient wore the appliance. From the images gained, a three-dimensional reconstruction of the upper airway from the palatal plane was achieved. The images revealed statistically significant increases in the volume of the upper airway with the use of a modified functional appliance. Three-dimensional studies of the upper airway show greater detail and therefore seem likely to have more validity than two-dimensional studies.

[Postoperative mental confusion in the elderly with hip fracture. Perioperative risk factors]

OBJECTIVE

To determine the incidence of postoperative mental confusion and perioperative risk factors in elderly patients with femoral neck fractures.

PATIENTS AND METHODS

A prospective study of patients 65 years of age or older undergoing surgery for hip fracture with intradural anesthesia between March 1992 and August 1993. Although the total number of cases came to 162, only 50 patients were enrolled in the study: the rest were excluded mainly because of mental deficits presenting before surgery. Folstein's Mini-Mental State test was used to assess mental function. Risk factors analyzed were classified as preoperative, intraoperative (in the operating room and the recovery room) or postoperative (hospital ward).

RESULTS

Eleven (22%) patients showed signs of postoperative mental confusion. Simple analysis revealed a correlation between mental confusion and ASA (p = 0.01), neuropsychiatric history (p = 0.03) and preoperative hemoglobulin, red blood cell and urea nitrogen levels (p = 0.02). Multifactorial discriminant analysis indicated that patients with low red cell counts before surgery, high urea nitrogen and neuropsychiatric histories were more predisposed (p = 0.004) to mental confusion.

CONCLUSIONS

A high incidence of postoperative mental confusion is associated to pre-surgical factors. We therefore suggest that greater preventive and therapeutic efforts be directed preferably to preparation before surgery, especially in patients at high risk.

[Headache following dural puncture in pregnant patients at term. Comparative study with non-obstetric patients]

OBJECTIVES

To compare the incidence of postdural puncture headache after subarachnoid anesthesia with a 24G Sprotte needle among full-term obstetric patients as compared to non-obstetric patients.

PATIENTS AND METHODS

A total of 200 patients were studied prospectively, divided into 2 groups. Group 1 (n = 100) patients were delivered by cesarean section and group 2 (n = 100) patients underwent infraumbilical or traumatological surgery. All were ASA I-II and under 40 years of age. Hydration was accomplished with lactated Ringer's solution 400-1,000 ml before mid-line puncture. The anesthetic used in both groups was isobaric bupivacaine 0.5% with a vasoconstrictor. The incidence of arterial hypotension and accompanying symptoms was recorded; perioperative administration of vasoactive amines and anticholinergics and liquids administered was measured. Twenty-four to 48 hours later the patients were asked when they started walking and if postdural puncture headache was experienced.

RESULTS

Group 1 received smaller doses of bupivacaine (p < 0.05) and the incidence of arterial hypotension was greater (p < 0.01) and required increased administration of amines (p < 0.01) and perioperative fluid therapy (p < 0.001). No difference was found between the two groups either for time of start of ambulation or for incidence of headache, which was 1% in both groups.

CONCLUSIONS

The incidence of postdural puncture headache in obstetric patients is low and similar to that of non-obstetric patients when the 24G Sprotte needle is used.

[Renal hypertrophy studied by techniques of nuclear medicine in post-nephrectomy patients]

Study of group of 61 patients, nephrectomized as a result of various diseases and who before and three months after surgery underwent blood pressure, effective renal plasma flow (EPFF) and unilateral renal function determinations in order to verify the compensating ability of the remaining kidney. Effective renal plasma flow was determined by a single injection and removal of six serial blood samples with 125-I-Hippuran. Unilateral renal function was determined from the relative uptake of 99mTc-DMSA 24 hours after injection. The patients were divided into four groups according to their overall and unilateral renal function as well as the presence or absence of hypertension. Patients with normal EPFF and symmetrical renal function showed a significantly increase in the function of the remaining kidney after surgery (p < 0.001). Patients with normal or slightly reduced EPFF (< 10%) and highly asymmetrical unilateral function as well as those with decreased EPFF (> 10%) and symmetrical or asymmetrical unilateral renal function did not increased the function of the remaining kidney after nephrectomy, and hypertensive patients whose blood pressure returned to normal values after nephrectomy had a decreased function of the remaining kidney after surgery (< 0.001). It is concluded that it is possible to predict the functional behaviour of the remaining kidney after nephrectomy, and that the compensating ability will basically depend on the previously existing (overall and unilateral) renal function as well as the presence or absence of hypertension.

Immunoscintigraphy of lung cancer using 111In-labelled antiCEA F023C5-F(ab')2 fragments

Forty-one patients with known lung carcinoma or suspicion of bearing this disease were studied with 111In-antiCEA F023C5-F(ab')2. Five patients with positive results were further studied to assess in vivo specificity using 111In-4C4-F(ab')2 (MoAb antihepatitis). Immunoscintigraphic results have been compared to immunohistochemistry in 16 patients. Tumour visualization with non-specific MoAb was present in all five patients although the maximum tumour/background (T/B) ratio obtained was 1.51. Therefore a 'specificity criterion' has been applied to examinations performed with MoAb antiCEA. There was considered to be a positive result when the T/B ratio was greater than 1.60. Results obtained in this way for thoracic lesions were 25/34 true positive (TP) (73%) and 6/7 true negative (TN) (86%). When studies were analysed visually only, the results were 32/34 TP (94%) and 3/7 TN (43%). In addition, immunoscintigraphic results are more concordant with immunohistochemical results when the specificity criterion is applied. In metastatic lesions results were 9/13 TP (69%) with only 1/3 TP (33%) for liver metastasis (anatomic site of lowest detection ability). SPECT imaging did not improve results over planar images, although it clearly contributed to a better anatomic location of lesions. The constant presence of non-specific uptake in thoracic lesions makes it necessary to establish a T/B ratio limit in order to obtain adequate specificity with the immunoscintigraphic technique.

Extrathoracic staging of bronchogenic carcinoma

In assessing the value of systematic evaluation of extrathoracic extension for potentially resectable, non-small-cell bronchogenic carcinoma, a prospective study was conducted in 146 patients. The study protocol included computed tomographic (CT) scan of the brain and upper abdomen, abdominal ultrasonography, and whole-body bone scanning. The findings were matched with the clinical presentation, histologic features, and TN staging, having found out that non-small cell bronchogenic carcinoma does not follow a set pattern to metastasize. The rate of metastasis for adenocarcinoma is not only significantly larger (p less than 0.05) but it does not correlate with the TN staging, in contrast to what happens with the squamous cell carcinoma (p less than 0.01). None of the squamous cell carcinomas in intrathoracic stage I was found to metastasize. Twenty-one percent (4/19) of brain metastases were asymptomatic (three adenocarcinomas and one squamous cell carcinoma with multiorgan metastasis). Bone scanning detected metastasis in 3.4 percent (4/116) of the asymptomatic patients, and three of the four patients with asymptomatic metastasis had nonskeletal foci. In 61 percent (11/18) of patients with hepatic metastasis, we did not find organ-specific indicators to suspect it. The series showed a 7.5 percent incidence of adrenal metastasis. Our findings suggest the convenience of performing an upper abdominal CT scan and/or ultrasonography in all patients, except for those with asymptomatic stage I squamous cell carcinoma; we also suggest brain CT scanning for all patients with adenocarcinomas and large-cell carcinomas as well as for those with squamous cell carcinoma with neurologic symptoms, and whole-body bone scanning only in those patients with clinical and laboratory indication of possible bone involvement by metastatic disease.

[Transaxial tomography in the study of myocardial perfusion with thallium-201]

Stress and redistribution thallium-201 myocardial imaging using a transaxial single emission computed tomographic system has been applied to the diagnosis of coronary artery disease. Data sampling was performed along a limited 180 degree arc, obtaining 32 images in a continuous mode, at a rate of 20 seconds per image. The production of perfusion defects in patients was stimulated by exercise testing or by dipyridamole infusion. No significant differences existed when both tests were compared (p less than 0.01). Normal and abnormal patterns including the different pathophysiological alterations of myocardial ischemia were defined in three tomographic planes using this methodology. Patients with coronary disease are separated from patients without coronary disease with high probability (84%). Transaxial SPECT (single photon emission computerized tomography) provides a significant increment in sensitivity and specificity in relation to planar scintigraphy in the detection of myocardial infarction (91 and 100%, respectively); residual ischemia postinfarction (96 and 97%, respectively), and significant coronary artery disease (91 and 97%, respectively).