Exploratory analysis to predict pneumonitis during durvalumab consolidation therapy for patients with locally advanced non-small cell lung cancer from proteomic profiling of circulating extracellular vesicles.

BACKGROUND: Risk factors for predicting pneumonitis during durvalumab consolidation after chemoradiotherapy (CRT) in locally advanced non-small cell lung cancer (LA-NSCLC) are still lacking. Extracellular vesicles (EVs) play a crucial role in intercellular communication and are potential diagnostic tools for various diseases. METHODS: We retrospectively collected predurvalumab treatment serum samples from patients treated with durvalumab for LA-NSCLC, isolated EVs using anti-CD9 and anti-CD63 antibodies, and performed proteomic analyses. We examined EV proteins that could predict the development of symptomatic pneumonitis (SP) during durvalumab treatment. Potential EV-protein biomarkers were validated in an independent cohort. RESULTS: In the discovery cohort, 73 patients were included, 49 with asymptomatic pneumonitis (AP) and 24 with SP. Of the 5797 proteins detected in circulating EVs, 33 were significantly elevated (fold change [FC] > 1.5, p < 0.05) in the SP group, indicating enrichment of the nuclear factor kappa B (NF-κB) pathway. Patients with high levels of EV-RELA, an NF-κB subunit, had a higher incidence of SP than those with low levels of EV-RELA (53.8% vs. 13.4%, p = 0.0017). In the receiver operating characteristic analysis, EV-RELA demonstrated a higher area under the curve (AUC) than lung V20 (0.76 vs. 0.62) and was identified as an independent risk factor in the multivariate logistic regression analysis (p = 0.008, odds ratio 7.72). Moreover, high EV-RELA was also a predictor of SP in the validation cohort comprising 43 patients (AUC of 0.80). CONCLUSIONS: Circulating EV-RELA may be a predictive marker for symptomatic pneumonitis in patients with LA-NSCLC treated with durvalumab.

Real-World Effectiveness of Dupilumab for Patients with Severe Asthma: A Retrospective Study.

Background: Treatment with dupilumab, an anti-interleukin (IL)-4 receptor α monoclonal antibody that blocks both the IL-4 and IL-13 pathways, has demonstrated efficacy for the treatment of severe asthma (SA) with type 2 inflammation. However, few studies have focused on the efficacy of this biologic for the treatment of SA in a real-world setting. Methods: From April 2019 to December 2021, 26 Japanese patients with SA received dupilumab at Jikei University Hospital. We retrospectively evaluated the number of moderate-to-severe exacerbations, pulmonary function, maintenance dose of corticosteroids, biomarkers, and adverse events. Results: During a mean follow-up period of 12.6 months, 10 patients received dupilumab as the first biologic, and 16 switched to dupilumab from other biologics. Dupilumab treatment significantly reduced the number of annual exacerbations from 3.4 ± 4.1 to 1.6 ± 2.7 (/person-year, p < 0.01) at the last follow-up regardless of previous biologic use. The Asthma Control Test score significantly improved in all patients by six months after administration but tended to worsen by 24 months in patients with previous biologic use. On the other hand, blood eosinophil counts (BECs) transiently increased and peaked three to six months after administration. The peak timing can be affected by previous biologic use. Adverse events included wheezing immediately after injection, hypereosinophilia, mild conjunctivitis, and relapse of chronic eosinophilic pneumonia in the patient switched from benralizumab. Conclusion: Dupilumab treatment was useful for patients with SA in a real-world setting. However, the BEC should be monitored carefully, especially in patients who previously received anti-IL-5/IL-5 receptor antibody.

Involvement of Parkin-mediated mitophagy in the pathogenesis of chronic obstructive pulmonary disease-related sarcopenia.

BACKGROUND: Sarcopenia is characterized by the loss of skeletal muscle mass and strength and is associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). Cigarette smoke (CS) exposure, a major cause for COPD, induces mitochondrial damage, which has been implicated in sarcopenia pathogenesis. The current study sought to examine the involvement of insufficient Parkin-mediated mitophagy, a mitochondrion-selective autophagy, in the mechanisms by which dysfunctional mitochondria accumulate with excessive reactive oxygen species (ROS) production in the development of COPD-related sarcopenia. METHODS: The involvement of Parkin-mediated mitophagy was examined using in vitro models of myotube formation, in vivo CS-exposure model using Parkin-/- mice, and human muscle samples from patients with COPD-related sarcopenia. RESULTS: Cigarette smoke extract (CSE) induced myotube atrophy with concomitant 30% reduction in Parkin expression levels (P < 0.05). Parkin-mediated mitophagy regulated myotube atrophy by modulating mitochondrial damage and mitochondrial ROS production. Increased mitochondrial ROS was responsible for myotube atrophy by activating Muscle Ring Finger 1 (MuRF-1)-mediated myosin heavy chain (MHC) degradation. Parkin-/- mice with prolonged CS exposure showed enhanced limb muscle atrophy with a 31.7% reduction in limb muscle weights (P < 0.01) and 2.3 times greater MuRF-1 expression (P < 0.01) compared with wild-type mice with concomitant accumulation of damaged mitochondria and oxidative modifications in 4HNE expression. Patients with COPD-related sarcopenia exhibited significantly reduced Parkin but increased MuRF-1 protein levels (35% lower and 2.5 times greater protein levels compared with control patients, P < 0.01 and P < 0.05, respectively) and damaged mitochondria accumulation demonstrated in muscles. Electric pulse stimulation-induced muscle contraction prevented CSE-induced MHC reduction by maintaining Parkin levels in myotubes. CONCLUSIONS: Taken together, COPD-related sarcopenia can be attributed to insufficient Parkin-mediated mitophagy and increased mitochondrial ROS causing enhanced muscle atrophy through MuRF-1 activation, which may be at least partly preventable through optimal physical exercise.

Aspiration of Cerebrospinal Fluid Rhinorrhea as a Cause of Non-resolving Pneumonia.

We herein report two cases of cerebrospinal fluid (CSF) rhinorrhea associated with lung infiltrates. One patient presented with symptomatic non-resolving pneumonia, while the other was asymptomatic. In both cases, the lung infiltrates completely resolved when CSF leakage had subsided. Pulmonary involvement in CSF rhinorrhea is under-recognized, and despite being the definitive treatment, surgery for CSF rhinorrhea is typically postponed due to the presence of lung infiltrates. However, meningitis is a serious complication due to a delay in surgical management. Physicians should be made aware that CSF rhinorrhea is a potential cause of intractable lung infiltrates.

Possible relationship between esophageal dilatation and severity of M. abscessus pulmonary disease.

OBJECTIVES: Recently, incidence of Mycobacterium abscessus (Mab) pulmonary disease (Mab-PD) is increasing worldwide. We aimed to identify factors associated with severity of Mycobacterium abscessus (Mab) pulmonary disease (Mab-PD). METHODS: All patients diagnosed as Mab-PD based on the official ATS/IDSA statement between 2017 January 1 and 2021 July 31 were included (n = 13). We reviewed medical records, bacteriological and laboratory data of the patients. Severity of lung lesions and esophageal diameters in chest CT were quantitatively evaluated. Gaffky score in the sputum was used as airway mycobacterial burden. We explored the factors associated with high CT score and high Gaffky score. RESULTS: Maximum diameter of esophagus (MDE) in severe disease (CT score≧10) was greater than that in milder disease (CT score<10) (18.0±7.9mm, 9.3±3.1mm, respectively, p = 0.01), and MDE was well correlated with CT score (R = 0.69, p = 0.007). MDE in high mycobacterial burden group (Gaffky score ≧5) tended to be greater than that in low mycobacterial burden group (Gaffky score <5) (16.1±6.8mm, 10.1±5.5mm, respectively, p = 0.12), and MDE was well correlated with Gaffky score (R = 0.68, p = 0.009). Lung lesions were bilateral and predominant in middle or lower lobes. CONCLUSIONS: Esophageal dilatation was correlated with severity of Mab-PD and airway mycobacterial burden. Gastroesophageal reflux might be associated with Mab disease progression.

Impaired TRIM16-Mediated Lysophagy in Chronic Obstructive Pulmonary Disease Pathogenesis.

Insufficient autophagic degradation has been implicated in accelerated cellular senescence during chronic obstructive pulmonary disease (COPD) pathogenesis. Aging-linked and cigarette smoke (CS)-induced functional deterioration of lysosomes may be associated with impaired autophagy. Lysosomal membrane permeabilization (LMP) is indicative of damaged lysosomes. Galectin-3 and tripartite motif protein (TRIM) 16 play a cooperative role in recognizing LMP and inducing lysophagy, a lysosome-selective autophagy, to maintain lysosome function. In this study, we sought to examine the role of TRIM16-mediated lysophagy in regulating CS-induced LMP and cellular senescence during COPD pathogenesis by using human bronchial epithelial cells and lung tissues. CS extract (CSE) induced lysosomal damage via LMP, as detected by galectin-3 accumulation. Autophagy was responsible for modulating LMP and lysosome function during CSE exposure. TRIM16 was involved in CSE-induced lysophagy, with impaired lysophagy associated with lysosomal dysfunction and accelerated cellular senescence. Airway epithelial cells in COPD lungs showed an increase in lipofuscin, aggresome and galectin-3 puncta, reflecting accumulation of lysosomal damage with concomitantly reduced TRIM16 expression levels. Human bronchial epithelial cells isolated from COPD patients showed reduced TRIM16 but increased galectin-3, and a negative correlation between TRIM16 and galectin-3 protein levels was demonstrated. Damaged lysosomes with LMP are accumulated in epithelial cells in COPD lungs, which can be at least partly attributed to impaired TRIM16-mediated lysophagy. Increased LMP in lung epithelial cells may be responsible for COPD pathogenesis through the enhancement of cellular senescence.

Effectiveness of Switching Biologics for Severe Asthma Patients in Japan: A Single-Center Retrospective Study.

BACKGROUND: In Japan, biologic therapy was initiated for patients with severe asthma in 2009. In recent years, four biologics with different mechanisms of action have become available in the clinical setting. However, the efficacy of switching between biologics remains uncertain. METHODS: To elucidate the efficacy of switching between biologics, 97 patients were enrolled who had received any biologic therapy for severe asthma at Jikei University Hospital, Tokyo, Japan, from July 2009 to December 2020. We retrospectively examined the patient characteristics, biomarkers, pulmonary function test results, selected biologics, and efficacy. RESULTS: Thirty-one males and 66 females received any biologics. The mean age was 53.3 years at the initiation of biologic therapy. Initially, 33, 41, 15 and eight patients received omalizumab, mepolizumab, benralizumab, and dupilumab, respectively. Among three representative indicators for biologics administration, the peripheral blood eosinophil count, serum IgE levels and fractional exhaled nitric oxide, 64% of the patients had two indicators, and 28% had three indicators. Thirty-four patients (35%) switched from the initial biologic to another, and the reasons for switching included persistent asthmatic symptoms (n=22), schedule of hospital visits (n=5), and other reasons. Thus, the treatment was effective in 11 patients after switching. In addition, two patients received combination therapy with different biologics. Eighteen patients (19%) interrupted treatment for various reasons. Regardless of whether the biologic was the initial therapy, the overall efficacy of the four biologics was 60% based on the global evaluation of treatment effectiveness. CONCLUSION: Switching between biologics can be a promising option for severe asthma patients in whom treatment with an initial biologic is ineffective.

Chaperone-Mediated Autophagy Suppresses Apoptosis via Regulation of the Unfolded Protein Response during Chronic Obstructive Pulmonary Disease Pathogenesis.

Cigarette smoke (CS) induces accumulation of misfolded proteins with concomitantly enhanced unfolded protein response (UPR). Increased apoptosis linked to UPR has been demonstrated in chronic obstructive pulmonary disease (COPD) pathogenesis. Chaperone-mediated autophagy (CMA) is a type of selective autophagy for lysosomal degradation of proteins with the KFERQ peptide motif. CMA has been implicated in not only maintaining nutritional homeostasis but also adapting the cell to stressed conditions. Although recent papers have shown functional cross-talk between UPR and CMA, mechanistic implications for CMA in COPD pathogenesis, especially in association with CS-evoked UPR, remain obscure. In this study, we sought to examine the role of CMA in regulating CS-induced apoptosis linked to UPR during COPD pathogenesis using human bronchial epithelial cells (HBEC) and lung tissues. CS extract (CSE) induced LAMP2A expression and CMA activation through a Nrf2-dependent manner in HBEC. LAMP2A knockdown and the subsequent CMA inhibition enhanced UPR, including CHOP expression, and was accompanied by increased apoptosis during CSE exposure, which was reversed by LAMP2A overexpression. Immunohistochemistry showed that Nrf2 and LAMP2A levels were reduced in small airway epithelial cells in COPD compared with non-COPD lungs. Both Nrf2 and LAMP2A levels were significantly reduced in HBEC isolated from COPD, whereas LAMP2A levels in HBEC were positively correlated with pulmonary function tests. These findings suggest the existence of functional cross-talk between CMA and UPR during CSE exposure and also that impaired CMA may be causally associated with COPD pathogenesis through enhanced UPR-mediated apoptosis in epithelial cells.

Dasatinib-induced Nonspecific Interstitial Pneumonia That Developed 7 Years after the Initiation of Dasatinib.

We report the case of a 56-year-old man with chronic myeloid leukemia (CML) who developed dasatinib-induced interstitial lung disease (ILD) 7 years after starting dasatinib, a BCR-ABL1 inhibitor. The patient presented with dyspnea. Chest imaging showed diffuse ground-glass opacities. A surgical lung biopsy showed cellular non-specific interstitial pneumonia (NSIP). Corticosteroid treatment ameliorated his condition. Bosutinib, another BCR-ABL1 inhibitor, was successfully re-instituted. The present case and relevant literature suggest that dasatinib-induced ILD can present as NSIP after an extended period, responds to corticosteroids, and is amenable to re-challenge at a lower-dose or with alternative BCR-ABL1 inhibitors.

Successful treatment of steroid-refractory immune checkpoint inhibitor-related pneumonitis with triple combination therapy: a case report.

Immune checkpoint inhibitor (ICI)-related pneumonitis is a relatively rare but clinically serious and potentially life-threatening adverse event. The majority of cases can be managed by drug discontinuation, with the administration of corticosteroids added in severe cases. However, worsening of pneumonitis can develop in a subset of patients despite treatment with high doses of corticosteroids. We herein report a case of steroid-refractory ICI-related pneumonitis in a recurrent non-small cell lung cancer (NSCLC) patient treated with pembrolizumab that was successfully improved by triple combination therapy (high-dose corticosteroids, tacrolimus, and cyclophosphamide). After 3 weeks of initial pembrolizumab administration, the patient was diagnosed with ICI-related pneumonitis. Chest computed tomography (CT) showed patchy distributed bilateral consolidation and ground-glass opacities (GGOs) with traction bronchiectasis and bronchiolectasis resembling the diffuse alveolar damage (DAD) radiographic pattern. Although methylprednisolone pulse therapy was initiated, worsening of respiratory failure resulted in the patient being transferred to the intensive care unit. Because of an insufficient therapeutic response to high-dose corticosteroids, tacrolimus and cyclophosphamide pulse therapy were additively performed as triple combination therapy according to the treatment strategy for pulmonary complications of clinically amyopathic dermatomyositis (CADM). In response to this triple combination therapy, the patient's respiratory condition gradually improved, and chest CT showed the marked amelioration of pulmonary opacities. This is the first report suggesting the efficacy of triple combination therapy (high-dose corticosteroids, tacrolimus, and cyclophosphamide) for steroid-refractory ICI-related pneumonitis complicated with respiratory failure.

The N-end rule pathway enzyme Naa10 supports epiblast specification in mouse embryonic stem cells by modulating FGF/MAPK.

N-terminal acetylation (Nt-acetylation) refers to the acetylation of the free α-amino group at the N-terminus of a polypeptide. While the effects of Nt-acetylation are multifaceted, its most known function is in the acetylation-dependent N-end rule protein degradation pathway (Ac/N-end rule pathway), where Nt-acetylation is recognized as a degron by designated E3 ligases, eventually leading to target degradation by the ubiquitin-proteasome system. Naa10 is the catalytic subunit of the major Nt-acetylation enzyme NatA, which Nt-acetylates proteins whose second amino acid has a small side chain. In humans, NAA10 is the responsible mutated gene in Ogden syndrome and is thought to play important roles in development. However, it is unclear how the Ac/N-end rule pathway affects the differentiation ability of mouse embryonic stem cells (mESCs). We hypothesized that the balance of pluripotency factors may be maintained by the Ac/N-end rule pathway. Thus, we established Naa10 knockout mESCs to test this hypothesis. We found that Naa10 deficiency attenuated differentiation towards the epiblast lineage, deviating towards primitive endoderm. However, this was not caused by disturbing the balance of pluripotency factors, rather by augmenting FGF/MAPK signaling.

Severe sepsis caused by Capnocytophaga canimorsus complicated by thrombotic microangiopathy in an immunocompetent patient.

Case: A 61-year-old man with an unremarkable medical history was admitted with fever 7 days after being bitten by his dog. On day 3, he showed altered mental status, and laboratory data showed progressive hemolytic anemia, thrombocytopenia, hyperbilirubinemia, renal dysfunction, coagulopathy, and schistocytosis. Severe sepsis complicated with thrombotic microangiopathy caused by Capnocytophaga canimorsus was suspected. Outcome: Plasma exchange was applied to treat the thrombotic microangiopathy and resulted in platelet count increase and improved renal function, hyperbilirubinemia, and schistocytosis. Blood culture results confirmed the presence of C. canimorsus. The patient was discharged in good condition. Conclusion: Capnocytophaga canimorsus is rare cause of severe sepsis, and should be suspected even in immunocompetent patients with dog-bite history. Capnocytophaga canimorsus infection may be complicated by thrombotic microangiopathy, for which plasma exchange should be considered prior to definitive diagnosis of thrombotic microangiopathy.

Computed Tomography of the Esophagus in Scleroderma and Lung Disease.

Systemic sclerosis, or scleroderma, is a collagen vascular disease characterized by hardening of the skin and involvement of internal organs, most commonly the esophagus. The most frequent cause of death in these patients is lung disease. Esophageal dysfunction has been implicated in the pathogenesis of interstitial lung disease. We previously developed a standard for the esophageal diameter on chest computed tomography (CT) and hypothesized that patients with esophageal dilation would be more likely to have interstitial lung disease than those without. In this study, we test this in 121 systemic sclerosis patients with interstitial lung disease and 48 of those without interstitial lung disease. For controls, we evaluated 121 patients followed at a general pulmonary clinic and the previously studied normal healthy standards. This study demonstrated that esophageal dilation is common in systemic sclerosis patients (66.3% for the maximal esophageal diameter more than or equal to 15 mm), that systemic sclerosis patients with interstitial lung disease have more dilated esophagi than those without interstitial lung disease (median 19.4 mm vs. 14.1 mm), and that esophageal parameters are negatively correlated with pulmonary function. We also found that patients from general pulmonary clinic were more likely to have dilated esophagi than normal controls (median 12.1 mm vs. 9.7 mm). The CT measurement of esophageal diameter may be a useful marker of patients at risk for developing lung disease.

Role of GADD45a in murine models of radiation- and bleomycin-induced lung injury.

We previously reported protective effects of GADD45a (growth arrest and DNA damage-inducible gene 45 alpha) in murine ventilator-induced lung injury (VILI) via effects on Akt-mediated endothelial cell signaling. In the present study we investigated the role of GADD45a in separate murine models of radiation- and bleomycin-induced lung injury. Initial studies of wild-type mice subjected to single-dose thoracic radiation (10 Gy) confirmed a significant increase in lung GADD45a expression within 24 h and persistent at 6 wk. Mice deficient in GADD45a (GADD45a(-/-)) demonstrated increased susceptibility to radiation-induced lung injury (RILI, 10 Gy) evidenced by increased bronchoalveolar lavage (BAL) fluid total cell counts, protein and albumin levels, and levels of inflammatory cytokines compared with RILI-challenged wild-type animals at 2 and 4 wk. Furthermore, GADD45a(-/-) mice had decreased total and phosphorylated lung Akt levels both at baseline and 6 wk after RILI challenge relative to wild-type mice while increased RILI susceptibility was observed in both Akt(+/-) mice and mice treated with an Akt inhibitor beginning 1 wk prior to irradiation. Additionally, overexpression of a constitutively active Akt1 transgene reversed RILI-susceptibility in GADD45a(-/-) mice. In separate studies, lung fibrotic changes 2 wk after treatment with bleomycin (0.25 U/kg IT) was significantly increased in GADD45a(-/-) mice compared with wild-type mice assessed by lung collagen content and histology. These data implicate GADD45a as an important modulator of lung inflammatory responses across different injury models and highlight GADD45a-mediated signaling as a novel target in inflammatory lung injury clinically.

Biomarker-based detection of asthma-COPD overlap syndrome in COPD populations.

Asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) was proposed by the science committees of both Global Initiative for Asthma (GINA) and Global Initiative for Chronic Obstructive Lung Disease (GOLD). However, the definition of ACOS has remained unclear all over the world, and the prevalence rate of ACOS is basically dependent on the patient's symptoms or the physician's opinion, based on questionnaire testing. In the current case report, we investigated the prevalence rate of COPD patients with high levels of fractional exhaled nitric oxide (FENO) or immunoglobulin E (IgE) as candidate markers of ACOS in COPD, as a multicenter, cross-sectional study. Outpatients with COPD were enrolled from Tohoku University Hospital, Sendai, Japan, and five hospitals (Tohoku University Hospital, Sendai, Japan; NTT East Tohoku Hospital, Sendai, Japan; Wakayama Medical University Hospital, Kimiidera, Japan; Hiraka General Hospital, Yokote, Japan; Iwate Prefectural Isawa Hospital, Oshu, Japan) with pulmonary physicians from March 1, 2013 to February 28, 2014. When they were estimated using 35 ppb as the cutoff value of FENO, the prevalence rate of ACOS was 16.3% in COPD. When estimated by both FENO and IgE, the high-FENO/high-IgE group was 7.8% in COPD. To the best of our knowledge, this study is the first to detect the prevalence rate of ACOS in COPD populations by using objective biomarkers. The results from the current study should be useful to identify the subgroup requiring early intervention by inhaled corticosteroids/long-acting beta agonist combination in COPD in order to improve the long-term management for ACOS.

Native-valve endocarditis caused by Mycobacterium chelonae, misidentified as polymicrobial gram-positive bacillus infection.

Mycobacterium chelonae, a species of rapidly growing mycobacteria, may grow in routine blood culture media and stain as gram-positive bacilli, which may cause diagnostic confusion. A patient with native-valve endocarditis caused by M. chelonae, which was misidentified as various gram-positive bacilli, is presented.

Inhibition of serine palmitoyltransferase delays the onset of radiation-induced pulmonary fibrosis through the negative regulation of sphingosine kinase-1 expression.

The enforcement of sphingosine-1-phosphate (S1P) signaling network protects from radiation-induced pneumonitis. We now demonstrate that, in contrast to early postirradiation period, late postirradiation sphingosine kinase-1 (SphK1) and sphingoid base-1-phosphates are associated with radiation-induced pulmonary fibrosis (RIF). Using the mouse model, we demonstrate that RIF is characterized by a marked upregulation of S1P and dihydrosphingosine-1-phosphate (DHS1P) levels in the lung tissue and in circulation accompanied by increased lung SphK1 expression and activity. Inhibition of sphingolipid de novo biosynthesis by targeting serine palmitoyltransferase (SPT) with myriocin reduced radiation-induced pulmonary inflammation and delayed the onset of RIF as evidenced by increased animal lifespan and decreased expression of markers of fibrogenesis, such as collagen and α-smooth muscle actin (α-SMA), in the lung. Long-term inhibition of SPT also decreased radiation-induced SphK activity in the lung and the levels of S1P-DHS1P in the lung tissue and in circulation. In vitro, inhibition or silencing of serine palmitoyltransferase attenuated transforming growth factor-ß1 (TGF-ß)-induced upregulation of α-SMA through the negative regulation of SphK1 expression in normal human lung fibroblasts. These data demonstrate a novel role for SPT in regulating TGF-ß signaling and fibrogenesis that is linked to the regulation of SphK1 expression and S1P-DHS1P formation.

Reduction of vinyl groups in naturally occurring chlorophylls-a.

3,8-Divinyl-chlorophyll(Chl)-a possessing a phytyl ester was hydrogenated in acetone by rhodium catalyst on alumina to afford 3-vinyl-8-ethyl-, 3-ethyl-8-vinyl- and 3,8-diethyl-Chls. The ratio of produced 3-ethyl-8-vinyl- over 3-vinyl-8-ethyl-Chls was determined to be 1.2, indicating that the reactivity of the 3-vinyl group was slightly higher than that of the 8-vinyl group. Catalytic hydrogenation of divinyl-protochlorophyll-a possessing a porphyrin π-skeleton (C17C18) instead of the above chlorin moiety (C17H-C18H) gave an equal amount of mono-reduced regioisomers. The slight (or no) selectivity is different from that in the enzymatic reduction of divinyl-(proto)chlorophyllides-a lacking a phytyl ester in the biosynthetic pathway of Chl-a where the sole 8-vinyl group is transformed to the ethyl group.

Splenic syndrome: a rare indication for splenectomy.

Splenic infarction due to sickle cell trait and high-altitude stress has been reported in the literature. Contributing factors leading to infarction are degree of altitude stress and status of physical condition. Medical therapy, which consists of evacuation from high altitude, intravenous fluids, supplemental oxygen, and pain control, has been the mainstay of treatment. However, some patients require surgical intervention. We describe six patients with sickle cell trait who sustained splenic infarctions due to high-altitude stress; two of these patients required splenectomy for near-total splenic necrosis and intractable pain. A review of the literature demonstrates that the common indications for splenectomy are splenic rupture, extensive splenic necrosis, or persistent abdominal pain.