Patterns of proliferation and cell differentiation during hepatic ontogeny in the alpaca

The liver has multiple functions that change throughout ontogeny. South American camelids (SAC) have unique characteristics related to adaptation to extreme environments and metabolism. However, the process of hepatic cell differentiation has not been studied in any SAC. We study the patterns of cell differentiation and proliferation in the liver of the alpaca at different times of the ontogeny, excluding the hematopoietic components. Immunohistochemical techniques were performed in 66 specimens, including embryos, fetuses, neonates and adults. Supplementary analyses were performed by lectinhistochemistry. The hepatocytic differentiation was performed by the identification of Hepatocyte (Clone: ​​OCH1ES Dako®). It began in the specimens of 1.8-2.5 cm of crown to rump length (CRL), from Days 25-29 (ovulation = Day 0), continued during gestation and intensified towards its end. The cholangiocytic differentiation was performed by the identification of cytokeratin 7 (CK7, Dako®). It was manifested at the final of gestation (specimens of 28.4 cm CRL, from Day 223 onwards). Parenchymal cells underwent a process of gradual differentiation (differentiation of hepatocytes preceded that of cholangiocytes). Cell proliferation was observed along gestation using the nuclear proliferation antigen (PCNA) and Ki-67. Hepatic organogenesis in the alpacas shares similar differentiation and proliferation mechanisms with other altricial, but phylogenetically distant, species.

Intranasal Administration of Mesenchymal Stem Cell Secretome Reduces Hippocampal Oxidative Stress, Neuroinflammation and Cell Death, Improving the Behavioral Outcome Following Perinatal Asphyxia

Perinatal Asphyxia (PA) is a leading cause of motor and neuropsychiatric disability associated with sustained oxidative stress, neuroinflammation, and cell death, affecting brain development. Based on a rat model of global PA, we investigated the neuroprotective effect of intranasally administered secretome, derived from human adipose mesenchymal stem cells (MSC-S), preconditioned with either deferoxamine (an hypoxia-mimetic) or TNF-α+IFN-γ (pro-inflammatory cytokines). PA was generated by immersing fetus-containing uterine horns in a water bath at 37 °C for 21 min. Thereafter, 16 μL of MSC-S (containing 6 μg of protein derived from 2 × 10⁵ preconditioned-MSC), or vehicle, were intranasally administered 2 h after birth to asphyxia-exposed and control rats, evaluated at postnatal day (P) 7. Alternatively, pups received a dose of either preconditioned MSC-S or vehicle, both at 2 h and P7, and were evaluated at P14, P30, and P60. The preconditioned MSC-S treatment (i) reversed asphyxia-induced oxidative stress in the hippocampus (oxidized/reduced glutathione); (ii) increased antioxidative Nuclear Erythroid 2-Related Factor 2 (NRF2) translocation; (iii) increased NQO1 antioxidant protein; (iv) reduced neuroinflammation (decreasing nuclearNF-κB/p65 levels and microglial reactivity); (v) decreased cleaved-caspase-3 cell-death; (vi) improved righting reflex, negative geotaxis, cliff aversion, locomotor activity, anxiety, motor coordination, and recognition memory. Overall, the study demonstrates that intranasal administration of preconditioned MSC-S is a novel therapeutic strategy that prevents the long-term effects of perinatal asphyxia.

[Follow-up in lung transplant by the study of the pulmonary epithelial permeability and the pulmonary scintigraphies of ventilation and perfusion: preliminary results]

INTRODUCTION

Acute rejection is the most common complication in lung transplantation.

OBJECTIVE

This work aimed to assess the contribution of pulmonary clearance of radioaerosols and relative pulmonary perfusion to diagnose acute rejection in lung transplantation.

MATERIAL AND METHOD

We have designed a prospective study and present the results obtained for the preliminary phase. This work includes 5 patients who have received a lung transplantation and in whom 28 studies of pulmonary clearance of 99mTc-DTPA and relative pulmonary perfusion with 99mTc microspheres were performed. The pulmonary biopsy diagnosed 9 rejection episodes, 2 associated to CMV infection.

RESULTS

The mean radioaerosol clearance time increased when the follow-up was favorable and decreased in 6 of the 9 rejection episodes, including 2 associated to CMV infection. There was only one case with decreased mean clearance time that was not associated to rejection.

CONCLUSIONS

Calculating relative pulmonary perfusion can be useful in the follow-up of single lung transplantation but not in bipulmonary ones. Our results suggest that measuring 99mTc-DTPA clearance is useful to suspect a rejection episode.

[Effects of treatment with OKT3 on brain perfusion in a heart transplant patient with SPET with 99mTc-HMPAO]

A heart transplant patient treated with OKT3 developed a severe headache which worsened and was accompanied by a sudden decrease in the patient's consciousness level and aphasia when the treatment course was completed. CT was performed and was normal. SPET imaging with 99mTc-HMPAO of cerebral blood flow done 16 hours later revealed multiple and clear focal defects in the blood flow. Analysis of cerebral spinal fluid revealed aseptic pleocytosis. Five days after the completion of treatment, the symptoms remitted and a new control SPET 3 weeks later was completely normal. A diagnosis of neurotoxicity secondary to OKT3 administration was established.

[Postoperative uptake of Ga-67 in planar scintigraphy and SPECT after median sternotomy]

Surgical alterations after median sternotomy can difficult the interpretation of scintigraphic images with Ga67. To analize the use of Ga67 scintigraphy in this patology, we wanted to know the Ga67 distribution in patients who had suffered median sternotomy. We studied 8 patients in the first month after median sternotomy without infection complication and performed planar images and SPECT. Ga67 showed uptake in liver, spleen and bone. Sternal uptake was greater or lesser than liver uptake but always showed an homogeneous distribution. No mediastinum uptake was observed. Surgical wound showed Ga67 uptake during the first week after sternotomy. To know the <<normal>> distribution of Ga67 in patients after median sternotomy allows the scan interpretation when we suspect infectous complications.

[A Spanish multicenter scintigraphic study of the breast using Tc 99m MIBI. Report of results]

The aim of this work has been to study, with a homogenous method, a wide sample of patients with breast cancer suspicion, in order to evaluate the real clinical usefulness of the scintimammography with MIBI-99mTc.

METHODS AND MATERIAL

We have studied by way of prone scintimammography 388 patients (418 lesions) with breast cancer suspicion. In the mammography the size and degree of breast cancer suspicion was evaluated. Diagnosis was established by biopsy.

RESULTS

247 lesions were diagnosed as breast cancer and 171 as benign diseases. She results of the scintimammography were sensitivity 90%, specificity 70%, PPV 81% and NPV 83%. In palpable lesions sensitivity and specificity were 94% and 61%, and in non-palpable lesions 75% and 81% respectively. In 264 lesions mammographic breast cancer suspicion was establish. 13 of the 14 FN results were obtained in lesions with a high malignancy suspicion. In lesions with a low or indeterminate suspicion, sensitivity and NPV of the scintimammography were 97% and 98%.

CONCLUSIONS

Scintimammography has a high sensitivity but a relatively low specificity in the study of lesions with breast cancer suspicion. Scintimammography could be a good complement of the mammography in lesions with a low or indeterminate suspicion of malignancy.

[Study of primary hyperparathyroidism by double-phase gammagraphy using Tc99m-MIBI: preoperative detection of pathological glands]

The preoperative use of imaging techniques to localize the diseased glands in primary hyperparathyroidism is still the subject of controversy. This paper assess the use of double-phase 99mTc-MIBI scintigraphy with that purpose. We examined 37 patients with primary hyperparathyroidism before surgical intervention. Two planar images 10 minutes and 3 hours after injection of 99mTc-MIBI were acquired. Final diagnosis was adenoma in 32 patients, 30 of whom had a positive scintigraphy (sensitivity 94%), with only two false negative results. In the other five patients, four with hyperplasia and one carcinoma, scintigraphy was also positive. Radioisotopic study was of particular interest in 5 patients who had undergone previous surgery; in one case, other diseased gland was located in the neck, and an ectopic adenoma was found in the remaining four cases. Two other ectopic lesions were also MIBI positive and, in these cases, scintigraphy was a direct indication for mediastinal surgery. There was no false positive results. We conclude that the high sensitivity and easy performance make double-phase 99mTc-MIBI scintigraphy the technique of choice for the preoperative localization of diseased glands in primary hyperparathyroidism, especially in cases of adenoma. Its use is of particular interest in adenomas with aberrant location and in patients who have undergone previous surgery.