Evolution of SARS-CoV-2 related pneumatoceles: A case report

Pneumatoceles are thin-walled, air or fluid-filled cysts within the lung parenchyma typically formed due to inflammation or bronchial injury from infectious and non-infectious etiologies. To our knowledge, there are only a handful of cases in the literature reporting complicated pneumatoceles as a result of acute respiratory distress without the use of positive-pressure ventilation. We present a unique case of a 34-year-old male who rapidly developed complicated pneumatoceles associated with SARS-CoV-2 pneumonia, without positive pressure ventilation, with complete resolution after conservative management.

Transitioning selexipag to oral treprostinil in patients with pulmonary artery hypertension

There are no prospective studies or guidelines describing transition between selexipag and oral treprostinil. We present two different transition strategies from selexipag to oral treprostinil, one started inpatient and then completed at home, and one completely under outpatient settings. Neither patient experienced worsening prostacyclin-type adverse effects; both were rigorous in their attention to a 7–8 hour administration schedule for oral treprostinil, and both experienced objective clinical benefit at follow-up. Prospective studies are needed to help guide clinical decisions when patients remain intermediate risk after a trial of either drug.

Vasodilator use in precapillary pulmonary hypertension with end stage kidney disease: A single center experience

BACKGROUND AND OBJECTIVES

Pulmonary hypertension is commonly seen in end stage kidney disease and is most commonly due to elevated left heart pressures. There is limited data about vasodilator use during the management of Group 1 pulmonary arterial hypertension in the context of those who also have or later developed end stage kidney disease. The objective of this study was to determine safety and efficacy of vasodilator therapy in precapillary pulmonary hypertension requiring renal replacement therapy.

DESIGN

This was a single-center retrospective case series. Patients were identified from our Pulmonary Hypertension Clinic using a historical roster from 2012 to 2020. Patients were included if they >18 years of age, had Group 1 or Group 4 (precapillary) pulmonary hypertension on right heart catheterization, and also had end stage kidney disease requiring either intermittent hemodialysis or peritoneal dialysis.

RESULTS

18 patients were identified with invasively confirmed Group 1 or Group 4 pulmonary hypertension and end stage kidney disease on renal replacement therapy. Scleroderma was the most common etiology for renal failure. 17 patients were treated with vasodilator therapy. Fifteen patients had paired right heart catheterizations that showed a significant decrease in mean pulmonary artery pressure and pulmonary vascular resistance. Therapy was relatively well tolerated but hypotension was common and midodrine was often helpful. Two patients had successful renal transplantation after starting vasodilator therapy.

CONCLUSION

We found vasodilator therapy was reasonably well tolerated and associated with a drop in mean pressure and pulmonary vascular resistance in patients with end stage kidney disease on dialysis.

Insights From Invasive Cardiopulmonary Exercise Testing of Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

BACKGROUND

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) affects tens of millions worldwide; the causes of exertional intolerance are poorly understood. The ME/CFS label overlaps with postural orthostatic tachycardia (POTS) and fibromyalgia, and objective evidence of small fiber neuropathy (SFN) is reported in approximately 50% of POTS and fibromyalgia patients.

RESEARCH QUESTION

Can invasive cardiopulmonary exercise testing (iCPET) and PGP9.5-immunolabeled lower-leg skin biopsies inform the pathophysiology of ME/CFS exertional intolerance and potential relationships with SFN?

STUDY DESIGN AND METHODS

We analyzed 1,516 upright invasive iCPETs performed to investigate exertional intolerance. After excluding patients with intrinsic heart or lung disease and selecting those with right atrial pressures (RAP) <6.5 mm Hg, results from 160 patients meeting ME/CFS criteria who had skin biopsy test results were compared with 36 control subjects. Rest-to-peak changes in cardiac output (Qc) were compared with oxygen uptake (Qc/VO₂ slope) to identify participants with low, normal, or high pulmonary blood flow by Qc/VO₂ tertiles.

RESULTS

During exercise, the 160 ME/CFS patients averaged lower RAP (1.9 ± 2 vs 8.3 ± 1.5; P < .0001) and peak VO₂ (80% ± 21% vs 101.4% ± 17%; P < .0001) than control subjects. The low-flow tertile had lower peak Qc than the normal and high-flow tertiles (88.4% ± 19% vs 99.5% ± 23.8% vs 99.9% ± 19.5% predicted; P < .01). In contrast, systemic oxygen extraction was impaired in high-flow vs low- and normal-flow participants (0.74% ± 0.1% vs 0.88 ± 0.11 vs 0.86 ± 0.1; P < .0001) in association with peripheral left-to-right shunting. Among the 160 ME/CFS patient biopsies, 31% were consistent with SFN (epidermal innervation ≤5.0% of predicted; P < .0001). Denervation severity did not correlate with exertional measures.

INTERPRETATION

These results identify two types of peripheral neurovascular dysregulation that are biologically plausible contributors to ME/CFS exertional intolerance-depressed Qc from impaired venous return, and impaired peripheral oxygen extraction. In patients with small-fiber pathology, neuropathic dysregulation causing microvascular dilation may limit exertion by shunting oxygenated blood from capillary beds and reducing cardiac return.

Effect of prenatal uterine position on male and female rats sexual behavior

It is well known that female rats developing close to a male in utero show a higher frequency of heterotypical or male-like behavior in adulthood, and have longer anogenital distances. The present investigation was designed to evaluate the in utero masculine influence on the homotypical sexual behavior of male and female rats. Also explored was the influence on body weight on Gestation Day 21 (day of cesarean delivery) and 21, 40. and 120 days after birth, testicle weight following the gonadectomy of males on Day 40, and serum testosterone in males and females on the day of delivery. The presence of a contiguous male fetus located caudally with respect to uterine blood flow led to the masculinization of male-like behavior in male rats, the defeminization of female like behavior in females and to increased body weights on Day 21 of gestation in both sexes. No significant differences were detected in the remaining parameters. Findings indicated a gradation in the intensity of expression of male and female sexual behavior in adulthood related to the intrauterine position resulting in interindividual variability. The possible implication of this physiological phenomenon in the structure of rodent populations is discussed.

Comparative study of the use of poly(glycolic acid), calcium alginate and pluronics in the engineering of autologous porcine cartilage

New cartilage formation has been successfully achieved by technology referred to as tissue engineering. Polymers and hydrogels such as poly(glycolic acid), calcium alginate, and poly(ethylene) and poly(propylene) hydrogels have been used as cell carriers to regenerate cartilage in the nude mouse model. The next step toward human applications of engineered cartilage is to demonstrate their potential in immunocompetent animal models. This study compared the suitability of three polymers for generating tissue engineered elastic cartilage using autologous cells in an immuno-competent porcine animal model. Auricular cartilage was obtained from pigs. Chondrocytes were isolated onto fiber based poly(glycolic acid) (PGA) scaffolds or suspended in calcium alginate or pluronic F127 gel at constant concentrations. Chondrocyte-polymer constructs were either implanted (PGA) or injected (calcium alginate and pluronic) as autologous implants subcutaneously into the pigs from which the cells had been isolated. Specimens were harvested and analyzed grossly and historically after 6 weeks in vivo. All explants demonstrated cartilage formation to a variable degree. When using PGA or calcium alginate, the overall histological appearance of the tissue formed is that of fibrocartilage with thick bundles of collagen dispersed in the tissue. When using pluronics as scaffold, histologic features resemble those of native elastic cartilage, showing a more organized arrangement of the cells, which seems to correlate to functional properties as elastin presence in the tissue engineered cartilage. Elastic cartilage engineered in an immunocompetent animal model varies with the type of polymer used. The behavior of the cell-polymer constructs is not fully understood and outcome seems to be related to several factors, including inflammatory reaction. Further studies with similar models are needed to determine the feasibility of engineering tissue generated from different cell-polymer constructs prior to human application.

Isolation from Trypanosoma cruzi-infected mice of CD8+, MHC-restricted cytotoxic T cells that lyse parasite-infected target cells

Recent in vivo depletion studies in mice demonstrated that CD8+ T cells play a critical role in acute resistance to experimental Trypanosoma cruzi infections. As part of efforts to characterize these protective CD8+ T cell effector populations, we report here that splenic lymphocytes from mice chronically infected with T. cruzi can be induced to express high levels of cytolytic activity after stimulation in vitro with irradiated T. cruzi-infected macrophages. Cytolytic activity can either be detected using a nonspecific lectin-dependent 51Cr-release assay or using 51Cr-labeled T. cruzi-infected target cells. Fresh splenocytes from chronically infected mice stimulated with T. cruzi-infected macrophages exhibit relatively "promiscuous" killing activity inasmuch as significant lysis of both T. cruzi-infected and uninfected syngeneic and allogeneic cells is detected. However, subsequent rounds of in vitro stimulation lead to the expression of lytic activity that is T. cruzi Ag-specific and MHC-restricted. Several short term in vitro maintained cytolytic T cell lines were shown to have mixed phenotypes by FACS analysis; approximately 50% to 75% of the cells in these populations were CD4-, CD8+, whereas 20% to 40% were CD4-, CD8-. Experiments in which effector cells were positively selected by adherence to anti-CD8 mAb-treated plates confirmed that CD8+ T cell could exhibit Ag-specific cytolytic activity against T. cruzi-infected target cells. Efforts are under way to clone these CTL to test their in vivo function and to determine their Ag specificity.

Isolation from Trypanosoma cruzi-infected mice of CD8+, MHC-restricted cytotoxic T cells that lyse parasite-infected target cells

Recent in vivo depletion studies in mice demonstrated that CD8+ T cells play a critical role in acute resistance to experimental Trypanosoma cruzi infections. As part of efforts to characterize these protective CD8+ T cell effector populations, we report here that splenic lymphocytes from mice chronically infected with T. cruzi can be induced to express high levels of cytolytic activity after stimulation in vitro with irradiated T. cruzi-infected macrophages. Cytolytic activity can either be detected using a nonspecific lectin-dependent 51Cr-release assay or using 51Cr-labeled T. cruzi-infected target cells. Fresh splenocytes from chronically infected mice stimulated with T. cruzi-infected macrophages exhibit relatively "promiscuous" killing activity inasmuch as significant lysis of both T. cruzi-infected and uninfected syngeneic and allogeneic cells is detected. However, subsequent rounds of in vitro stimulation lead to the expression of lytic activity that is T. cruzi Ag-specific and MHC-restricted. Several short term in vitro maintained cytolytic T cell lines were shown to have mixed phenotypes by FACS analysis; approximately 50% to 75% of the cells in these populations were CD4-, CD8+, whereas 20% to 40% were CD4-, CD8-. Experiments in which effector cells were positively selected by adherence to anti-CD8 mAb-treated plates confirmed that CD8+ T cell could exhibit Ag-specific cytolytic activity against T. cruzi-infected target cells. Efforts are under way to clone these CTL to test their in vivo function and to determine their Ag specificity.

Antibiotic management of outpatients with endocarditis due to penicillin-susceptible streptococci

Thirty patients with endocarditis caused by penicillin-susceptible streptococci were enrolled in one of two groups in this study. Fifteen patients received ceftriaxone (2 g once daily) for 4 weeks; the other 15 received the same dosage of ceftriaxone for 2 weeks and then received oral amoxicillin (1 g four times a day) for 2 weeks. For the 27 patients treated predominantly as outpatients, 380 days of hospitalization were avoided. Clinical cure was achieved for all patients in both groups. We conclude that ceftriaxone, alone or followed by a course of amoxicillin, is an efficacious mode of treatment for infective endocarditis caused by penicillin-susceptible streptococci. Treatment with these agents can be administered predominantly on an outpatient basis.

[Relationship between various erythrocyte antigens and hematologic disorders]

The antigen pattern pertaining to the ABO (A, B, AB, O (H)), Rh (D, C, c, E, e), Duffy (Fya and b), Kell (K, k) and MNS (M, N) systems were determined in 144 patients between 1 and 74 years of age who had leukemia, lymphoma or myeloma. An association of phenotype Fy (a-b+) with acute lymphatic leukemia and phenotype NN with chronic myeloid leukemia was demonstrated (p less than 0.05, chi sq). Other associations were statistically not significant. Thus, a susceptibility of the aforementioned phenotype patterns to the type of leukemia described is suggested by these findings.

A prospective evaluation of bacteremic patients with chronic liver disease

We prospectively studied 51 consecutive bacteremic patients with chronic liver disease in order to evaluate their clinical presentation and to assess the relationship of various clinical parameters to mortality. Forty-two patients had alcoholic liver disease and 40 were in Class C, by the Pugh modification of Child's criteria. Soft tissue infections were the most common source of bacteremia, followed by pneumonia, spontaneous bacterial peritonitis and urinary tract infection. Gram positive organisms were isolated in 69% of cases, and Gram negative ones in 31%. In nine patients, no source of bacteremia was detected. Leukocytosis occurred in 59% of patients and bandemia in only 41%. Although appropriate antibiotic therapy was begun in all cases on admission, 17 patients (33%) died in the hospital. Of 38 clinical parameters evaluated, multivariate analysis revealed that the three variables contributing the most independent information toward predicting in-hospital mortality were the absence of a history of fever, an elevated serum creatinine and marked leukocytosis. Improved understanding of the pathophysiologic relationship between these parameters and patient outcome may enable us to improve the therapy of bacteremic patients with chronic liver disease.