Sacral nerve stimulation effect on colonic motility in pediatric patients

BACKGROUND

Sacral nerve stimulation (SNS) is a minimally invasive surgical procedure used to treat refractory constipation in children. While its efficacy in improving symptoms has been studied, its effect on colonic motor function remains unclear. This case series explores SNS's impact on colonic motor function in pediatric patients with idiopathic constipation, using high-resolution colonic manometry (HRCM).

METHODS

Four pediatric patients with chronic idiopathic constipation underwent SNS placement for intractable symptoms and were subsequently evaluated via HRCM. Clinical characteristics, comorbidities, treatment regimens, and outcomes were reviewed. HRCM was conducted during the SNS-off and SNS-on phases. The motility index (MI) was measured during the SNS-off (fasting and postprandial) and SNS-on phases.

RESULTS

Four pediatric patients aged 8 to 21 years met the inclusion criteria. In three patients, SNS-induced high-amplitude propagating contractions (HAPCs) were noted, and in one patient, low-amplitude propagating contractions (LAPCs) were noted. In one patient, propagating contractions were induced only when SNS was turned on. MI changes with SNS-on were variable among different patients with an increase in MI in two patients after turning SNS on and a decrease in the other two compared with baseline. Adverse effects following SNS placement remained minimal across all cases.

CONCLUSION

This case series is the first to report SNS effects on colonic motility evaluated by HRCM in pediatrics. We demonstrate that propagating colonic contractions are promptly induced when SNS is turned on. Although the initial effects of SNS on colonic motility were observable, additional investigation is necessary to comprehend the fundamental mechanisms and long-term effectiveness of SNS in pediatric patients.

Frequency, kinetics and determinants of viable SARS-CoV-2 in bioaerosols from ambulatory COVID-19 patients infected with the Beta, Delta or Omicron variants

Airborne transmission of SARS-CoV-2 aerosol remains contentious. Importantly, whether cough or breath-generated bioaerosols can harbor viable and replicating virus remains largely unclarified. We performed size-fractionated aerosol sampling (Andersen cascade impactor) and evaluated viral culturability in human cell lines (infectiousness), viral genetics, and host immunity in ambulatory participants with COVID-19. Sixty-one percent (27/44) and 50% (22/44) of participants emitted variant-specific culture-positive aerosols <10μm and <5μm, respectively, for up to 9 days after symptom onset. Aerosol culturability is significantly associated with lower neutralizing antibody titers, and suppression of transcriptomic pathways related to innate immunity and the humoral response. A nasopharyngeal Ct <17 rules-in ~40% of aerosol culture-positives and identifies those who are probably highly infectious. A parsimonious three transcript blood-based biosignature is highly predictive of infectious aerosol generation (PPV > 95%). There is considerable heterogeneity in potential infectiousness i.e., only 29% of participants were probably highly infectious (produced culture-positive aerosols <5μm at ~6 days after symptom onset). These data, which comprehensively confirm variant-specific culturable SARS-CoV-2 in aerosol, inform the targeting of transmission-related interventions and public health containment strategies emphasizing improved ventilation.

Unusual Presentation of a Hepatic Neuroendocrine Tumor With Elevated CEA and CA 19-9: A Case Report

Neuroendocrine tumors (NETs) of the gastrointestinal tract (GIT) are rare malignancies, which may have unique presentations. The diagnostic process predominantly relies on immunohistochemical analysis. While tumor markers are extensively utilized in diagnosing and monitoring GI malignancies, their specific role in NETs has not been fully explored. This case describes an 83-year-old male presenting with jaundice and general weakness. Diagnostic imaging through MRI and CT angiography (CTA) revealed a nodular texture on the liver's surface suggesting cirrhosis. The presence of elevated tumor markers, specifically carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA 19-9), raised suspicions of malignancy. A subsequent liver biopsy confirmed the diagnosis of small-cell high-grade neuroendocrine carcinoma accompanied by reactive fibrosis. As per our knowledge, this case is the first recorded instance of a liver neuroendocrine tumor (NET) exhibiting elevated levels of both CEA and CA 19-9, with no abnormalities detected in the gallbladder, biliary tree, and bowel in the MRI with magnetic resonance cholangiopancreatography (MRCP) and CTA. This is an atypical presentation of a liver NET, mimicking cirrhotic liver morphology, and underscores the potential diagnostic relevance of tumor markers CEA and CA 19-9 in such cases.

Unveiling the Unexpected: Why Doctors Should Look beyond the Lungs when Predicting COVID-19 Mortality

INTRODUCTION

The main objective of this study was to identify the best combination of admission day parameters for predicting COVID-19 mortality in hospitalized patients. Furthermore, we sought to compare the predictive capacity of pulmonary parameters to that of renal parameters for mortality from COVID-19.

METHODS

In this retrospective study, all patients admitted to a tertiary hospital between September 1st, 2020, and December 31st, 2020, who were clinically symptomatic and tested positive for COVID-19, were included. We gathered extensive data on patient admissions, including laboratory results, comorbidities, chest X-ray (CXR) images, and SpO2 levels, to determine their role in predicting mortality. Experienced radiologists evaluated the CXR images and assigned a score from 0 to 18 based on the severity of COVID-19 pneumonia. Further, we categorized patients into two independent groups based on their renal function using the RIFLE and KDIGO criteria to define the acute kidney injury (AKI) and chronic kidney disease (CKD) groups. The first group ("AKI&CKD") was subdivided into six subgroups: normal renal function (A); CKD grade 2+3a (B); AKI-DROP (C); CKD grade 3b (D); AKI-RISE (E); and grade 4 + 5 CKD (F). The second group was based only on estimated glomerular filtration rate (eGFR) at the admission, and thus it was divided into four grades: grade 1, grade 2+3a, grade 3b, and grade 4 + 5.

RESULTS

The cohort comprised 619 patients. Patients who died during hospitalization had a significantly higher mean radiological score compared to those who survived, with a p value <0.01. Moreover, we observed that the risk for mortality was significantly increased as renal function deteriorated, as evidenced by the AKI&CKD and eGFR groups (p < 0.001 for each group). Regarding mortality prediction, the area under the curve (AUC) for renal parameters (AKI&CKD group, eGFR group, and age) was found to be superior to that of pulmonary parameters (age, radiological score, SpO2, CRP, and D-dimer) with an AUC of 0.8068 versus 0.7667. However, when renal and pulmonary parameters were combined, the AUC increased to 0.8813. Optimal parameter combinations for predicting mortality from COVID-19 were identified for three medical settings: Emergency Medical Service (EMS), the Emergency Department, and the Internal Medicine Floor. The AUC for these settings was 0.7874, 0.8614, and 0.8813, respectively.

CONCLUSIONS

Our study demonstrated that selected renal parameters are superior to pulmonary parameters in predicting COVID-19 mortality for patients requiring hospitalization. When combining both renal and pulmonary factors, the predictive ability of mortality significantly improved. Additionally, we identified the optimal combination of factors for mortality prediction in three distinct settings: EMS, Emergency Department, and Internal Medicine Floor.

Can Renal Parameters Predict the Mortality of Hospitalized COVID-19 Patients?

Introduction

Our study aimed to analyze whether renal parameters can predict mortality from COVID-19 disease in hospitalized patients.

Methods

This retrospective cohort includes all adult patients with confirmed COVID-19 disease who were consecutively admitted to the tertiary hospital during the 4-month period (September 1 to December 31, 2020). We analyzed their basic laboratory values, urinalysis, comorbidities, length of hospitalization, and survival. The RIFLE and KDIGO criteria were used for AKI and CKD grading, respectively. To display renal function evolution and the severity of renal damage, we subdivided patients further into 6 groups as follows: group 1 (normal renal function), group 2 (CKD grades 2 + 3a), group 3 (AKI-DROP defined as whose s-Cr level dropped by >33.3% during the hospitalization), group 4 (CKD 3b), group 5 (CKD 4 + 5), and group 6 (AKI-RISE defined as whose s-Cr level was elevated by ≥50% within 7 days or by ≥26.5 μmol/L within 48 h during hospitalization). Then, we used eGFR on admission independently of renal damage to check whether it can predict mortality. Only 4 groups were used: group I − normal renal function (eGFR > 1.5 mL/s), group II − mild renal involvement (eGFR 0.75–1.5), group III − moderate (eGFR 0.5–0.75), and group IV − severe (GFR <0.5).

Results

A total of 680 patients were included in our cohort; among them, 244 patients displayed normal renal function, 207 patients fulfilled AKI, and 229 patients suffered from CKD. In total, a significantly higher mortality rate was found in the AKI and the CKD groups versus normal renal function − 37.2% and 32.3% versus 9.4%, respectively (p < 0.001). In addition, the groups 1–6 divided by severity of renal damage reported mortality of 9.4%, 21.2%, 24.1%, 48.7%, 62.8%, and 55.1%, respectively (p < 0.001). The mean hospitalization duration of alive patients with normal renal findings was 9.5 days, while it was 12.1 days in patients with any renal damage (p < 0.001). When all patients were compared according to eGFR on admission, the mortality was as follows: group I (normal) 9.8%, group II (mild) 22.1%, group III (moderate) 40.9%, and group IV (severe) 50.5%, respectively (p < 0.001). It was a significantly better mortality predictor than CRP on admission (AUC 0.7053 vs. 0.6053).

Conclusions

Mortality in patients with abnormal renal function was 3 times higher compared to patients with normal renal function. Also, patients with renal damage had a worse and longer hospitalization course. Lastly, eGFR on admission, independently of renal damage type, was an excellent tool for predicting mortality. Further, the change in s-Cr levels during hospitalization reflected the mortality prognosis.

Cross-Sectional Study of the Prevalence of Cobalamin Deficiency and Vitamin B12 Supplementation Habits among Vegetarian and Vegan Children in the Czech Republic

Vegetarian (VG) and vegan (VN) diets in childhood are of growing interest due to their perceived health and environmental benefits. Concerns remain due to the possible disruption of healthy growth and development of children because of the scarcity of evidence-based studies. Among the nutrients of special concern is vitamin B12. Therefore, the Czech Vegan Children Study (CAROTS) decided to examine the relationship between B12 metabolism parameters and B12 intake through diet and supplementation. We analyzed laboratory parameters within n = 79 VG, n = 69 VN, and n = 52 omnivores (OM) children (0−18 years old). There were no significant differences in levels of holotranscobalamin (aB12), folate, homocysteine (hcys), or mean corpuscular volume. However, there was a significant difference in levels of cyanocobalamin (B12) (p = 0.018), even though we identified only n = 1 VG and n = 2 VN children as B12 deficient. On the other hand, we identified n = 35 VG, n = 28 VN, and n = 9 OM children with vitamin B12 hypervitaminosis (p = 0.004). This finding was related to a high prevalence of over-supplementation in the group (mean dose for VG 178.19 ± 238.5 µg per day; VN 278.35 ± 394.63 µg per day). Additionally, we found a significant (p < 0.05) difference between B12, aB12, and hcys levels of supplemented vs. non-supplemented VG/VN children. This can show that the intake of vitamin B12 via diet in the VG group might not be sufficient. Secondly, we analyzed a relation between supplement use in pregnancy and breastfeeding and its impact on vitamin B12 levels of children aged 0−3 years. Out of n = 46 mothers, only n = 3 (e.g., 6.5%) were not supplemented at all. We have not identified any clinical manifestation of B12 deficiency and only n = 1 child with low serum cobalamin, a child who did not receive vitamin B12 supplementation and whose mother took only low doses of vitamin B12 (25/µg/day).To conclude, we did not observe any life-threatening or severe consequences of laboratory-stated vitamin B12 deficiency; thus, our group was well supplemented. On the other hand, we have identified many subjects with vitamin B12 hypervitaminosis of unknown impact on their health. Further research and new guidelines for B12 supplementation among VG and VN children are needed.

Short and long-term impact of four sets of actions on acute ischemic stroke management in Rhône County, a population based before-and-after prospective study

Background

Optimizing access to recanalization therapies in acute ischemic stroke patients is crucial. Our aim was to measure the short and long term effectiveness, at the acute phase and 1 year after stroke, of four sets of actions implemented in the Rhône County.

Methods

The four multilevel actions were 1) increase in stroke units bed capacity and development of endovascular therapy; 2) improvement in knowledge and skills of healthcare providers involved in acute stroke management using a bottom-up approach; 3) development and implementation of new organizations (transportation routes, pre-notification, coordination by the emergency call center physician dispatcher); and 4) launch of regional public awareness campaigns in addition to national campaigns. A before-and-after study was conducted with two identical population-based cohort studies in 2006–7 and 2015–16 in all adult ischemic stroke patients admitted to any emergency department or stroke unit of the Rhône County. The primary outcome criterion was in-hospital management times, and the main secondary outcome criteria were access to reperfusion therapy (either intravenous thrombolysis or endovascular treatment) and pre-hospital management times in the short term, and 12-month prognosis measured by the modified Rankin Scale (mRS) in the long term.

Results

Between 2015–16 and 2006–7 periods ischemic stroke patients increased from 696 to 717, access to reperfusion therapy increased from 9 to 23% (p < 0.0001), calls to emergency call-center from 40 to 68% (p < 0.0001), first admission in stroke unit from 8 to 30% (p < 0.0001), and MRI within 24 h from 18 to 42% (p < 0.0001). Onset-to-reperfusion time significantly decreased from 3h16mn [2 h54-4 h05] to 2h35mn [2 h05-3 h19] (p < 0.0001), mainly related to a decrease in delay from admission to imaging. A significant decrease of disability was observed, as patients with mild disability (mRS [0–2]) at 12 months increased from 48 to 61% (p < 0.0001). Pre-hospital times, however, did not change significantly.

Conclusions

We observed significant improvement in access to reperfusion therapy, mainly through a strong decrease of in-hospital management times, and in 12-month disability after the implementation of four sets of actions between 2006 and 2016 in the Rhône County. Reducing pre-hospital times remains a challenge.

Potassium overdose using an oral solution: Potassium element expressed in grams as a packaging flaw contributing to medication error

Drug packaging contributes to the harm-benefit balance of a treatment. Poorly designed packaging can lead to drug misuse with serious consequences. We report a potassium double dose medication error concerning an oral solution. It was triggered by a packaging flaw related to the dosage indicated on the box, expressed for both potassium salt and elemental potassium. Standardizing the units used on packaging and for prescriptions, by using millimoles, could be a solution to avoid this type of medication error.

Is hydrogen storage possible in metal-doped graphite 2D systems in conditions found on Earth?

Density functional theory (DFT) calculations are performed for the adsorption energy of hydrogen and oxygen on graphene decorated with a wide set of metals (Li, Na, K, Al, Ti, V, Ni, Cu, Pd, Pt). It is found that oxygen interferes with hydrogen adsorption by either blocking the adsorption site or by the irreversible oxidation of the metal decoration. The most promising decorations are Ni, Pd, and Pt due to a reasonable relationship of adsorption energies which minimize the oxygen interference. The DFT results are used to parametrize a statistical mechanical model which allows evaluation of the effect of partial pressures in the gas phase during storage. According to this model, even in the most promising case, it is necessary to reduce the oxygen partial pressure close to ultrahigh vacuum conditions to allow hydrogen storage.

Dynamic proteomics of individual cancer cells in response to a drug

Why do seemingly identical cells respond differently to a drug? To address this, we studied the dynamics and variability of the protein response of human cancer cells to a chemotherapy drug, camptothecin. We present a dynamic-proteomics approach that measures the levels and locations of nearly 1000 different endogenously tagged proteins in individual living cells at high temporal resolution. All cells show rapid translocation of proteins specific to the drug mechanism, including the drug target (topoisomerase-1), and slower, wide-ranging temporal waves of protein degradation and accumulation. However, the cells differ in the behavior of a subset of proteins. We identify proteins whose dynamics differ widely between cells, in a way that corresponds to the outcomes-cell death or survival. This opens the way to understanding molecular responses to drugs in individual cells.

The C-terminus of mutant p53 is necessary for its ability to interfere with growth arrest or apoptosis

The ability to suppress wild type p53-independent apoptosis may play an important role in the oncogenicity of p53 mutant proteins. However, structural elements necessary for this activity are unknown. Furthermore, it is unclear whether this mutant p53 mediated inhibition is specific to the apoptotic pathway or a more general suppression of the cellular response to stress. We observed that an unmodified C-terminus was required for the suppression of apoptosis by the p53 135(Ala to Val) oncogenic p53 mutant. It was also required for the novel activity of G2 arrest suppression, the predominant response at low levels of genotoxic stress. These observations are consistent with a model whereby mutant p53 suppressive activity is not specific to the apoptotic pathway, but rather increases the threshold of genotoxic stress needed for a DNA damage response to occur. Furthermore, these observations indicate that it may be possible to selectively kill mutant p53 expressing cells based on the lower sensitivity of their growth arrest response.

Change of the death pathway in senescent human fibroblasts in response to DNA damage is caused by an inability to stabilize p53

The cellular function of p53 is complex. It is well known that p53 plays a key role in cellular response to DNA damage. Moreover, p53 was implicated in cellular senescence, and it was demonstrated that p53 undergoes modification in senescent cells. However, it is not known how these modifications affect the ability of senescent cells to respond to DNA damage. To address this question, we studied the responses of cultured young and old normal diploid human fibroblasts to a variety of genotoxic stresses. Young fibroblasts were able to undergo p53-dependent and p53-independent apoptosis. In contrast, senescent fibroblasts were unable to undergo p53-dependent apoptosis, whereas p53-independent apoptosis was only slightly reduced. Interestingly, instead of undergoing p53-dependent apoptosis, senescent fibroblasts underwent necrosis. Furthermore, we found that old cells were unable to stabilize p53 in response to DNA damage. Exogenous expression or stabilization of p53 with proteasome inhibitors in old fibroblasts restored their ability to undergo apoptosis. Our results suggest that stabilization of p53 in response to DNA damage is impaired in old fibroblasts, resulting in induction of necrosis. The role of this phenomenon in normal aging and anticancer therapy is discussed.

Oncogenic mutations of the p53 tumor suppressor: the demons of the guardian of the genome

The p53 guardian of the genome is inactivated in the majority of cancers, mostly through missense mutations that cause single residue changes in the DNA binding core domain of the protein. Not only do such mutations result in the abrogation of wild-type p53 activity, but the expressed p53 mutant proteins also tend to gain oncogenic functions, such as interference with wild-type p53-independent apoptosis. Because p53 mutants are highly expressed in cancer cells and not in normal cells, their reactivation to wild-type p53 function may eliminate the cancer by apoptosis or another p53-dependent mechanism. Several studies that embarked on this quest for reactivation have succeeded in restoring wildtype p53 activity to several p53 mutants. However, mutants with more extensive structural changes in the DNA binding core domain may be refractory to reactivation to the wild-type p53 phenotype. Therefore, understanding the structure and functions of oncogenic p53 mutants may lead to more potent reactivation modalities or to the ability to eliminate mutant p53 gain of function.

The LFA-1 integrin supports rolling adhesions on ICAM-1 under physiological shear flow in a permissive cellular environment

The LFA-1 integrin is crucial for the firm adhesion of circulating leukocytes to ICAM-1-expressing endothelial cells. In the present study, we demonstrate that LFA-1 can arrest unstimulated PBL subsets and lymphoblastoid Jurkat cells on immobilized ICAM-1 under subphysiological shear flow and mediate firm adhesion to ICAM-1 after short static contact. However, LFA-1 expressed in K562 cells failed to support firm adhesion to ICAM-1 but instead mediated K562 cell rolling on the endothelial ligand under physiological shear stress. LFA-1-mediated rolling required an intact LFA-1 I-domain, was enhanced by Mg2+, and was sharply dependent on ICAM-1 density. This is the first indication that LFA-1 can engage in rolling adhesions with ICAM-1 under physiological shear flow. The ability of LFA-1 to support rolling correlates with decreased avidity and impaired time-dependent adhesion strengthening. A beta2 cytoplasmic domain-deletion mutant of LFA-1, with high avidity to immobilized ICAM-1, mediated firm arrests of K562 cells interacting with ICAM-1 under shear flow. Our results suggest that restrictions in LFA-1 clustering mediated by cytoskeletal attachments may lock the integrin into low-avidity states in particular cellular environments. Although low-avidity LFA-1 states fail to undergo adhesion strengthening upon contact with ICAM-1 at stasis, these states are permissive for leukocyte rolling on ICAM-1 under physiological shear flow. Rolling mediated by low-avidity LFA-1 interactions with ICAM-1 may stabilize rolling initiated by specialized vascular rolling receptors and allow the leukocyte to arrest on vascular endothelium upon exposure to stimulatory endothelial signals.

The effects of decreased audibility produced by high-pass noise masking on cortical event-related potentials to speech sounds/ba/and/da

This study investigated the effects of decreased audibility produced by high-pass noise masking on cortical event-related potentials (ERPs) N1, N2, and P3 to the speech sounds /ba/and/da/presented at 65 and 80 dB SPL. Normal-hearing subjects pressed a button in response to the deviant sound in an oddball paradigm. Broadband masking noise was presented at an intensity sufficient to completely mask the response to the 65-dB SPL speech sounds, and subsequently high-pass filtered at 4000, 2000, 1000, 500, and 250 Hz. With high-pass masking noise, pure-tone behavioral thresholds increased by an average of 38 dB at the high-pass cutoff and by 50 dB one octave above the cutoff frequency. Results show that as the cutoff frequency of the high-pass masker was lowered, ERP latencies to speech sounds increased and amplitudes decreased. The cutoff frequency where these changes first occurred and the rate of the change differed for N1 compared to N2, P3, and the behavioral measures. N1 showed gradual changes as the masker cutoff frequency was lowered. N2, P3, and behavioral measures showed marked changes below a masker cutoff of 2000 Hz. These results indicate that the decreased audibility resulting from the noise masking affects the various ERP components in a differential manner. N1 is related to the presence of audible stimulus energy, being present whether audible stimuli are discriminable or not. In contrast, N2 and P3 were absent when the stimuli were audible but not discriminable (i.e., when the second formant transitions were masked), reflecting stimulus discrimination. These data have implications regarding the effects of decreased audibility on cortical processing of speech sounds and for the study of cortical ERPs in populations with hearing impairment.

Acute cholecystitis in diabetic patients

Postoperative outcome and severity of acute cholecystitis in 32 diabetic patients (DM) who underwent urgent cholecystectomy were compared on a case-control basis with 32 nondiabetic age/sex matched controls. There was no difference in incidence of renal and lung diseases or duration of acute symptoms before surgery. Cardiovascular diseases were more often seen in the diabetic group (16/32 in DM, 7/32 in controls, P = 0.03). Bactobilia was more often in diabetics (19 in DM, 11 in controls, p = 0.07). Postoperatively, there was a trend toward higher incidence in overall complication rate. Infectious complications (wound and respiratory infections, hepatic abscess) were higher in DM, although the difference was not statistically significant. One patient in DM group died as a result of multiorgan failure. There was no difference in total and postoperative hospital stay. The severity of acute cholecystitis was greater in diabetics (26 patients with moderate-to-severe cholecystitis in DM group, 18 in control group, P = 0.05). The study indicates that although pathological findings were more severe in DM group, the postoperative course is comparable in diabetics as compared to age and sex matched nondiabetic controls. Our findings justify reconsideration of prophylactic cholecystectomy in asymptomatic diabetic patients.

Total estradiol and progesterone receptor levels and DNA concentrations in human endometrium with nonuniform postovulatory delay of maturation

Total estradiol and progesterone receptor levels and DNA concentrations were measured in endometria of four women with nonuniform postovulatory delayed maturation of the epithelium. All four women underwent curettage on Days 21 to 23 of their cycle. The results in these women were compared with results obtained from a control group of women with histologically normal cyclic endometrium. In three women with corpus luteum defect, total estradiol and progesterone receptor levels and DNA concentrations were in the range of midcycle or early secretory normal (control) endometria. In one patient with a normally functioning corpus luteum, the above parameters were similar to those found in the late secretory phase of controls. Summation of the results of the present study along with those previously reported in endometria of women, both with uniform and nonuniform delayed maturation, indicate the possibility of endometrial postacceptorial progesterone defect, which may either be secondary to corpus luteum defect or a result of primary endometrial defect.

Effect of progesterone injection on progesterone receptor levels and distribution in untreated and short-term Premarin-primed pre-menopausal and post-menopausal endometrium

Cytosolic and nuclear progesterone receptors (RPC, RPN) were measured in post-menopausal endometria, using [3H]R5020 as the radioligand, and the findings compared with those in pre-menopausal endometria. Total RP levels (RPC + RPN) in post-menopausal endometria were low, i.e. less than 2000 fmol/mg DNA. A 7-11 day course of Premarin (conjugated equine oestrogen) treatment in post-menopausal subjects resulted in RP levels in 11818 +/- 3008 fmol/mg DNA, which were higher than those in proliferative, mid-cycle and Premarin-primed pre-menopausal endometria. Progesterone injection 1-3 h before tissue collection resulted in a change in the distribution of the RP in both premenopausal and post-menopausal Premarin-primed endometria and pre-menopausal proliferative and mid-cycle endometria. Following the progesterone injection RPN levels increased to 57 +/- 9% of the total as compared with 23 +/- 8% in endometrial samples from women who received no progesterone.