High-Resolution Transcriptomic Landscape of the Human Submandibular Gland.

Saliva-secreting and transporting cells are part of the complex cellular milieu of the human salivary gland, where they play important roles in normal glandular physiology and diseased states. However, comprehensive molecular characterization, particularly at single-cell resolution, is still incomplete, in part due to difficulty in procuring normal human tissues. Here, we perform an in-depth analysis of male and female adult human submandibular gland (SMG) samples by bulk RNA sequencing (RNA-seq) and examine the molecular underpinnings of the heterogeneous cell populations by single-cell (sc) RNA-seq. Our results from scRNA-seq highlight the remarkable diversity of clusters of epithelial and nonepithelial cells that reside in the SMG that is also faithfully recapitulated by deconvolution of the bulk-RNA data sets. Our analyses reveal complex transcriptomic heterogeneity within both the ductal and acinar subpopulations and identify atypical SMG cell types, such as mucoacinar cells that are unique to humans and ionocytes that have been recently described in the mouse. We use CellChat to explore ligand-receptor interactome predictions that likely mediate crucial cell-cell communications between the various cell clusters. Finally, we apply a trajectory inference method to investigate specific cellular branching points and topology that offers insights into the dynamic and complex differentiation process of the adult SMG. The data sets and the analyses herein comprise an extensive wealth of high-resolution information and a valuable resource for a deeper mechanistic understanding of human SMG biology and pathophysiology.

The unfinished work of neonatal very low birthweight infants quality improvement: Improving outcomes at a continental level in South America.

Neonatal mortality rate varies between 4.2 and 18.6 per thousand by country in South America. There is little information regarding the outcomes of very low birth weight infants in the region and mortality rates are extremely variable ranging from 6% to over 50%. This group may represent up to 50-70% of the neonatal mortality and approximately 25-30% of infant mortality. Some initiatives, like the NEOCOSUR Network, have systematically collected and analyzed epidemiological information on VLBW infants' outcomes in the region. Over a 16-year period, survival without major morbidity improved from 37 to 44%. However, mortality has remained almost unchanged at approximately 27%, despite an increase in the implementation of the best available evidence in perinatal practices over time. Implementing quality improvement initiatives in the continent is particularly challenging but represents a great opportunity considering that there is a wide margin for progress in both care and outcomes.

[The role of pulmonary hypertension on bronchopulmonary dysplasia]. / El rol de la hipertensión pulmonar en la displasia broncopulmonar.

50 years ago, Northway described Broncopulmonary Dysplasia (BPD) in preterm infants exposed to mechanical ventilation. Since then, their survival has increased, nevertheless a "new BPD" has appeared and its incidence has not diminished. One of the characteristics of this pathology is the the abnormal vascular remodeling, which in its most severe expression is known as Pulmonary Hyper tension (PH); with an incidence of 17% in patients with BPD, which is proportional to the severity of the disease (33% in severe BPD), and as mortality factor (up to 48% 2-year mortality in PH-BPD). Thereby, it is important to know the diagnostic methods and therapeutic alternatives, topics discus sed in this review. Considering the high mortality in BPD associated PH, screening strategies in at risk population become important. The gold standard is cardiac catheterization; however, transtho-rathic echocardiography is a useful tool for the screening and diagnosis of PH in displasic patients, using cuantitive measures and cualitative changes in the evaluation. Seric type-B natriuretic peptide has shown to be useful for follow-up; regarding images, CT scan is used in severe cases. In terms of therapy; inhaled Nitric Oxide as a pulmonary vasodilator, phosphodiesterase inhibitors -sildenafil-, endotelin antagonists -bosentan-, and prostacyclin analogues -iloprost-, have been proposed. Their use, dosis and treatment lenght still lack support of high quality evidence, but diverse clinical expe riences have been described. Interdisciplinary care is also important, highlighting to optimize nu trition. Therefore, the challenge is to effectively prevent BPD and its complications. A PH screening protocol should be associated with risk stratification and treatment guidelines.

Mode of delivery and antenatal steroids and their association with survival and severe intraventricular hemorrhage in very low birth weight infants.

OBJECTIVE: To determine whether CS delivery and receipt of antenatal steroids (ANS) in vertex-presenting singletons with a gestational age (GA) between 24 and 30 weeks is associated with improved survival and improved severe intraventricular hemorrhage (sIVH)-free survival. STUDY DESIGN: Multicenter cohort, retrospective analysis of prospectively collected data. Vertex-presenting singletons newborns with GA 24 to 30 weeks, birth weight between 500 and 1500 g, without major congenital malformations, born between 2001 and 2011 at Neocosur centers were included. RESULTS: Four thousand three hundred and eighty-six infants fulfilled inclusion criteria: 45.8% were delivered vaginally and 54.2% by cesarean section (CS). Newborns delivered vaginally received less ANS, had lower GA, Apgar scores and a lower incidence of survival and sIVH-free survival (P<0.001). Newborns with better survival were those with ANS, independent of mode of delivery. At 24 to 25 weeks GA, increased survival and sIVH-free survival were associated with ANS and CS delivery, compared with those who received ANS and delivered vaginally. CONCLUSIONS: Among vertex-presenting singletons with GA 24 to 30 weeks, better survival and IVH-free survival were associated with ANS, independent of mode of delivery. In infants at 24 to 25 weeks gestation the combination of ANS/CS was associated with improvement in both outcomes.

Effect of prophylactic CPAP in very low birth weight infants in South America.

OBJECTIVE: The objective of this study was to examine the effect of prophylactic continuous positive airway pressure (CPAP) on infants born in 25 South American neonatal intensive care units affiliated with the Neocosur Neonatal Network using novel multivariate matching methods. STUDY DESIGN: A prospective cohort was constructed of infants with a birth weight 500 to 1500 g born between 2005 and 2011 who clinically were eligible for prophylactic CPAP. Patients who received prophylactic CPAP were matched to those who did not on 23 clinical and sociodemographic variables (N=1268). Outcomes were analyzed using the McNemar's test. RESULTS: Infants not receiving prophylactic CPAP had higher mortality rates (odds ratio (OR)=1.69, 95% confidence interval (CI) 1.17, 2.46), need for any mechanical ventilation (OR=1.68, 95% CI 1.33, 2.14) and death or bronchopulmonary dysplasia (BPD) (OR=1.47, 95% CI 1.09, 1.98). The benefit of prophylactic CPAP varied by birth weight and gender. CONCLUSIONS: The implementation of this process was associated with a significant improvement in survival and survival free of BPD.

A risk prediction model for severe intraventricular hemorrhage in very low birth weight infants and the effect of prophylactic indomethacin.

OBJECTIVE: Develop a risk prediction model for severe intraventricular hemorrhage (IVH) in very low birth weight infants (VLBWI). STUDY DESIGN: Prospectively collected data of infants with birth weight 500 to 1249 g born between 2001 and 2010 in centers from the Neocosur Network were used. Forward stepwise logistic regression model was employed. The model was tested in the 2011 cohort and then applied to the population of VLBWI that received prophylactic indomethacin to analyze its effect in the risk of severe IVH. RESULT: Data from 6538 VLBWI were analyzed. The area under ROC curve for the model was 0.79 and 0.76 when tested in the 2011 cohort. The prophylactic indomethacin group had lower incidence of severe IVH, especially in the highest-risk groups. CONCLUSION: A model for early severe IVH prediction was developed and tested in our population. Prophylactic indomethacin was associated with a lower risk-adjusted incidence of severe IVH.

Sialolithiasis in a residual Wharton's duct after excision of a submandibular salivary gland.

Treatment of salivary stones includes both surgical and non-surgical techniques. Surgical approaches range from excision of the sialolith, for those near the duct orifice, to removal of the affected salivary gland and its associated duct, for stones near the hilum of the gland. We present a case of two sialoliths triggering an acute infection in a residual Wharton's duct, 12 years after the removal of the associated submandibular gland. Excision of the sialoliths and treatment of the infected duct via sialodochoplasty was successfully performed in this patient. If the Wharton's duct is not removed with the associated submandibular gland, the potential for infection and continuous growth of dormant calcifications exists. We also address the aetiology, pathogenesis, and management of patients with sialolithiasis in the absence of a major salivary gland.

Serendipitous diagnosis of protein S deficiency.

A 46-year-old male sought periodontal care for a swelling on his right mandibular gingiva. An excisional biopsy revealed a well-differentiated squamous cell carcinoma. Surgical treatment consisted of a right segmental mandibulectomy with ipsilateral right neck dissection and fibular free flap reconstruction. Two days after the surgical procedure, a weakened Doppler signal suggested vascular compromise of the graft. The patient was returned to the operating room where complete thrombosis of the internal jugular vein (recipient vessel) was observed. This event prompted a complete hematological evaluation that disclosed low serum levels of protein S. The patient was started on systemic heparin and local medicinal leeches. A week later, systemic warfarin sodium was added and successfully resolved the vascular compromise of the graft. Two years later, the patient is active and lives a full life with occasional adjustments of warfarin sodium. This case represents the first report on the treatment of gingival carcinoma that led to the serendipitous discovery of an unrelated and unusual systemic condition, protein S deficiency.

The effect of early dexamethasone administration on bronchopulmonary dysplasia in preterm infants with respiratory distress syndrome.

OBJECTIVES: This study was carried to evaluate the effect of early administration of dexamethasone on the incidence of bronchopulmonary dysplasia (BPD) and/or death in surfactant-treated preterm infants with respiratory distress syndrome (RDS). STUDY DESIGN: In a multicenter, double-blind, placebo-controlled trial, 109 preterm infants with RDS and birth weights between 700 and 1600 gm, who were treated with mechanical ventilation and surfactant, were randomly assigned before 36 hours of life to receive dexamethasone (n = 55) or placebo (n = 54) for 12 days. RESULTS: There were no differences in the incidence of BPD and/or death between groups. However, fewer patients in the dexamethasone group were oxygen-dependent at 36 weeks after conception (8% vs 33%, p < 0.05). The dexamethasone group had a lower incidence of necrotizing enterocolitis (0% vs 9%, p < 0.05). The incidence of arterial hypertension, hyperglycemia, and sepsis was not affected by the treatment. Basal and poststimulation serum cortisol levels did not differ between groups. CONCLUSION: The administration of dexamethasone early in the course of RDS does not decrease the incidence of BPD and/or death in preterm infants. However, dexamethasone may reduce oxygen dependency at 36 weeks after conception.

Does continuous positive airway pressure (CPAP) during weaning from intermittent mandatory ventilation in very low birth weight infants have risks or benefits? A controlled trial.

OBJECTIVE: The purpose of this study was to evaluate three ventilator weaning strategies and to evaluate whether the use of continuous positive airway pressure (CPAP) via a nasopharyngeal or endotracheal tube would increase the likelihood of extubation failure in very low birth weight (VLBW) infants. STUDY DESIGN: We studied prospectively 87 preterm infants (mean +/- SD; birth weight: 1078 +/- 188 g; gestational age: 28.8 +/- 2.2 weeks) who were in the process of being weaned from intermittent mandatory ventilation (IMV). Infants were assigned by systematic sampling to one of the following three treatment groups: (1) direct extubation from IMV (D.EXT) (n = 30); (2) preextubation endotracheal CPAP (ET-CPAP) for 12-24 hr (n = 28); or (3) postextubation nasopharyngeal CPAP (NP-CPAP) for 12-24 hr (n = 29). Failure was defined as the need for resumption of mechanical ventilation within 72 hr of extubation due to frequent or severe apnea and/or respiratory failure (pH < 7.25, PaCO2 > 60 mm Hg, and/or requirement for oxygen FiO2 > 60%). RESULTS: There were no significant differences in failure rates among the three procedures. Failures were 2/30 (7%) in D.EXT; 4/28 (14%) in ET-CPAP; and 7/29 (24%) in the NP-CPAP. There were also no differences in FiO2, PaO2, and respiratory rates before and after discontinuation of IMV among the three groups. PaCO2 values were slightly higher in the NP-CPAP group 12-24 hr after weaning from IMV. CONCLUSION: We were unable to demonstrate a clear difference in extubation outcome by use of CPAP administered via an endotracheal or nasopharyngeal tube when compared to direct extubation from low-rate IMV in VLBW infants.

Incidencia de lesiones cutáneas en el recién nacido / Incidence of cutaneous injuries in the newborn

En el recipen nacido se puede apreciar una gran variedad de lesiones cutáneas, que generalmente corresponden a cambios fisiológicos de la piel, transitorios y benignos. Sin embargo, se pueden presentar lesiones cutáneas marcadoras de enfermedades sistémicas, tumorales u otras enfermedades dermatológicas que tanto pediatras como dermatológos deben saber diferenciar. El objetivo de nuestro trabajo fue conocer la incidencia y frecuencia relativa de estos cambios cutáneos

Estimation of the time required by the malaria parasites to cross the digestive tract to reach blood in mice inoculated by the oral route.

In a previous report we described the transmission of the malaria parasites by the oral route in a murine model. Later, we performed some experiments to demonstrate the transmission of malaria infection by cannibalism. Now we commence to look for the site, mechanism and stages of the parasite involved in crossing the alimentary canal to reach blood and start the infection. To know the invasive stage of the parasite and the way it penetrates, we wanted first to find the level of the digestive tract through which the parasites cross, to restrict the area to be studied. We proposed that the crossing place would be known, if the crossing time of the parasite could be established. Mice were orally inoculated with Plasmodium yoelii yoelii infected blood and their blood was transferred at different times into clean recipient mice intraperitoneally. Malaria infection detected in recipient mice proved that infective forms of the parasite were circulating in the donor mice at the time the blood samples were taken. In this way, we observed that: i) although most parasites required between 2 to 10 min for crossing the alimentary canal, in some case the process can last for 22 hrs; ii) the parasites circulate in blood for variable periods of time (only two minutes in the shortest, and from 10 min on in the longest) being infective to blood recipients. Most orally-inoculated mice whose blood infects other mice, became transient carriers of parasites unable to establish in them.

Experimental transmission of Babesia microti infection by the oral route.

Previously we have described the transmission of malaria by the oral route in a murine model. Due to the similarities between Plasmodium and Babesia, we tried to reproduce oral transmission in parasites of the latter genus by ingestion of infected blood and by cannibalism. In the first case, experimental mice were inoculated orally with 20, 50, or 100 microliters of Babesia microti-infected blood, and in the second, each fasted experimental mouse was offered the corpse of an infected mouse serving as the bait inoculum. B. microti infection was acquired by 3.7% of all experimental animals orally inoculated with infected blood and by 15.1% of all mice inoculated by cannibalism. The approximate period of prepatency ran from 2 to 4 weeks. No control mouse acquired the infection. This represents the first time that oral transmission of babesiosis has been described. This kind of transmission may be present in nature. Babesiosis may be acquired and maintained in nature in the absence of ticks.

Experimental transmission of murine malaria by the oral route.

A total of 116 young male CD1 mice were orally inoculated with mouse blood; half of the animals received 0.2 ml of uninfected blood and the others were given 0.2 ml of Plasmodium berghei yoelii-infected blood in six experiments performed at different times. Almost 30% of the experimental mice acquired malaria as demonstrated by the observation of parasites in their blood. In no case were parasites found in the blood of control mice. Rodent malaria parasites may be transmitted to CD1 mice by the ingestion of mouse blood parasitized by P. b. yoelii. As far as we know, this study represents the first demonstration of oral transmission of murine malaria. Oral transmission studies in this mouse-Plasmodium model may produce very important information on the biology of the malaria parasites.

[Incidence of bronchopulmonary dysplasia]. / Incidencia de displasia broncopulmonar.

The incidence of bronchopulmonary dysplasia (BPD) was retrospectively studied in all ventilated newborns at a neonatal intensive care unit of a university based hospital at Santiago, Chile along a 5 years period (1983-1987). BPD incidence among the whole sample of newborn infants requiring artificial ventilation was analysed according to birth weight (BW) and compared with that of newborns surviving after 28 days of life. The possible association of BPD with hyaline membrane disease (HMD), ductus arteriosus (DA) and pulmonary air leak (PAL) was studied. The total number of ventilated newborns was 200, incidence of BPD was 9.5% (19/200) and lethality for BPD was 5.2% (1/19). The incidence of BPD increased progressively with decreasing BW, reaching 37.5% in infants less than 1,000 g (p less than 0.001 chi 2). Among 28 day survivors incidence of BPD in the same BW group increased to 75% (p less than 0.05). These findings support the idea that the incidence of BPD increases with improved survival of low birth weight infants. A positive association of BPD with DA and PAL was seen with 10/19 versus 33/181 incidence for DA (p less than 0.01) and 6/19 versus 16/181 for PAL (p less than 0.01) among patients with and those without BPD respectively, but not with HMD.

[Intrauterine growth in Chilean middle class newborn infants]. / Crecimiento intrauterino en recién nacidos chilenos de clase media.

Intrauterine growth of 11,543 newborn infants, liveborn between 1978 to 1987 that met prospective selection conditions (without intrauterine growth retardation risk) and their data are reported. MBW and weight percentiles 10, 25, 50, 75, 90 from 26 throughout 42 week of gestational age are reported. Selection of cases was important in obtaining adequate percentiles of birth-weight vs gestational age. The intrauterine growth pattern herein reported is recommended for evaluation of chilean newborns, because it is different to that of some foreign countries and the studied sample seems representative of chilean babies.