The mouse model of intellectual disability by ZBTB18/RP58 haploinsufficiency shows cognitive dysfunction with synaptic impairment.

ZBTB18/RP58 (OMIM *608433) is one of the pivotal genes responsible for 1q43q44 microdeletion syndrome (OMIM #612337) and its haploinsufficiency induces intellectual disability. However, the underlying pathological mechanism of ZBTB18/RP58 haploinsufficiency is unknown. In this study, we generated ZBTB18/RP58 heterozygous mice and found that these mutant mice exhibit multiple behavioral deficits, including impairment in motor learning, working memory, and memory flexibility, which are related to behaviors in people with intellectual disabilities, and show no gross abnormalities in their cytoarchitectures but dysplasia of the corpus callosum, which has been reported in certain population of patients with ZBTB18 haploinsufficiency as well as in those with 1q43q44 microdeletion syndrome, indicating that these mutant mice are a novel model of ZBTB18/RP58 haploinsufficiency, which reflects heterozygotic ZBTB18 missense, truncating variants and some phenotypes of 1q43q44 microdeletion syndrome based on ZBTB18/RP58 haploinsufficiency. Furthermore, these mice show glutamatergic synaptic dysfunctions, including a reduced glutamate receptor expression, altered properties of NMDA receptor-mediated synaptic responses, a decreased saturation level of long-term potentiation of excitatory synaptic transmission, and distinct morphological characteristics of the thick-type spines. Therefore, these results suggest that ZBTB18/RP58 haploinsufficiency leads to impaired excitatory synaptic maturation, which in turn results in cognitive dysfunction in ZBTB18 haploinsufficiency.

GAD67-mediated GABA Synthesis and Signaling Impinges on Directing Basket Cell Axonal Projections Toward Purkinje Cells in the Cerebellum.

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system, synthesized by two isoforms of glutamate decarboxylase (GAD): GAD65 and GAD67. GABA may act as a trophic factor during brain development, but its contribution to the development and maturation of cerebellar neural circuits is not known. To understand the roles of GABA in cerebellar organization and associated functions in motor coordination and balance, we examined GAD65 conventional knock out (KO) mice and mice in which GAD67 was eliminated in parvalbumin-expressing neurons (PV-Cre; GAD67flox/flox mice). We found aberrant subcellular localization of the Shaker-type K channel Kv1.1 in basket cell collaterals of PV-Cre; GAD67 flox/flox mice and abnormal projections from basket cells to Purkinje cells in both mouse strains. We also found that altered synaptic properties of basket cell terminals to Purkinje cells in PV-Cre; GAD67flox/flox mice. Furthermore, PV-Cre; GAD67 flox/flox mice exhibited abnormal motor coordination in the rotarod test. These results indicate that GABA signaling in the cerebellum is critical for establishing appropriate connections between basket cells and Purkinje cells and is associated with motor coordination in mice.

Multimodal Functional Analysis Platform: 1. Ultrathin Fluorescence Endoscope Imaging System Enables Flexible Functional Brain Imaging.

To elucidate the expression mechanisms of brain functions, we have developed an ultrathin fluorescence endoscope imaging system (U-FEIS) that can image cells in the brain at any depth while minimizing the invasion. The endoscope part of U-FEIS consists of a GRIN lens and a 10,000-pixel image fiber with a diameter of 450 µm. The specialized microscope of U-FEIS is within 30 cm square and includes lenses and optical filters optimized for the endoscope. Using U-FEIS, we successfully visualized neurons expressing GFP with single-cell resolution and recorded the multineuronal activities in vitro and in vivo. U-FEIS can also perform imaging and optical stimulation simultaneously. Therefore, U-FEIS should be a powerful optical tool in neuroscience research.

Temperature elevation in epileptogenic foci exacerbates epileptic discharge through TRPV4 activation.

Physiological brain temperature is an important determinant of brain function, and it is well established that changes in brain temperature dynamically influence hippocampal neuronal activity. We previously demonstrated that the thermosensor TRPV4 is activated at physiological brain temperature in hippocampal neurons thereby controlling neuronal excitability in vitro. Here, we examined whether TRPV4 regulates neuronal excitability through its activation by brain temperature in vivo. We locally cooled the hippocampus using our novel electrical device and demonstrated constitutive TRPV4 activation in normal mouse brain. We generated a model of partial epilepsy by utilizing kindling stimuli in the ventral hippocampus of wild type (WT) or TRPV4-deficient (TRPV4KO) mice and obtained electroencephalograms (EEG). The frequencies of epileptic EEG in WT mice were significantly larger than those in TRPV4KO mice. These results indicate that TRPV4 activation is involved in disease progression of epilepsy. We expected that disease progression would enhance hyperexcitability and lead to hyperthermia in the epileptogenic foci. To confirm this hypothesis, we developed a new device to measure exact brain temperature only in a restricted local area. From the recording results by the new device, we found that the brain temperatures in epileptogenic zones were dramatically elevated compared with normal regions. Furthermore, we demonstrated that the temperature elevation was critical for disease progression. Based on these results, we speculate that brain cooling treatment at epileptogenic foci would effectively suppress epileptic discharges through inhibition of TRPV4. Notably, the cooling treatment drastically suppressed neuronal discharges dependent on the inactivation of TRPV4.

Long-Term Outcome of Chronic Thromboembolic Pulmonary Hypertension at a Single Japanese Pulmonary Endarterectomy Center.

BACKGROUND: Several new treatments for chronic thromboembolic pulmonary hypertension (CTEPH) have appeared in recent years, which have led to changes in the treatment algorithm. Changes in survival rates and prognostic factors, however, have not been estimated so far.Methods and Results:Two hundred and eighty patients were diagnosed with CTEPH at Chiba University Hospital between June 1986 and June 2016. Survival rate was investigated by date of treatment initiation (group 1, 1986-1998; group 2, 1999-2008; group 3, 2009-2016). Survival rates were also evaluated by treatment strategy: balloon pulmonary angioplasty (BPA), pulmonary endarterectomy (PEA), and medical treatment. Group 3 had significantly better disease-specific survival than groups 1 and 2 (5-year survival: 91.9% vs. 67.1%, 77.0%, respectively). For the non-PEA (BPA+medication) strategy, group 3 had better disease-specific survival than groups 1 and 2 (5-year survival: 94.9% vs. 54.6%, 74.2%, respectively). The PEA strategy had significantly better survival than the medication strategy in groups 1 and 2, whereas no difference was observed between the BPA, PEA, and medication strategies in group 3. CONCLUSIONS: Survival in CTEPH in the recent era has significantly improved, especially in non-PEA patients. BPA and selective pulmonary vasodilators could improve survival in the non-PEA group. In the present study, no difference in survival was found between PEA and non-PEA.

Mean Pulmonary Artery Pressure Using Echocardiography in Chronic Thromboembolic Pulmonary Hypertension.

BACKGROUND: Mean pulmonary arterial pressure (MPAP) is an important pulmonary hemodynamic parameter used in the management of patients with chronic thromboembolic pulmonary hypertension (CTEPH). We compared echocardiography-derived estimates of MPAP with right heart catheterization (RHC) to identify reliable noninvasive methods of estimating MPAP-derived RHC (MPAPRHC) in these patients. METHODS AND RESULTS: Echocardiography and RHC were performed in 56 patients with CTEPH (60.5±12.0 years; 44 females). We measured the tricuspid regurgitation (TR) pressure gradient (TRPG) using echocardiography. The mean systolic right ventricular (RV)-right atrial (RA) gradient was calculated by tracing the TR time velocity flow. Systolic and mean pulmonary artery pressures (SPAPTRand MPAPTR) estimated from TRPG and mean systolic RV-RA gradient were calculated by adding RA pressure based on the inferior vena cava. MPAPChemlawas calculated using Chemla's formula: 0.61×SPAPTR+2 mmHg. MPAPRHCand pulmonary vascular resistance were 35.9±11.3 mmHg and 6.6±3.6 Wood units, respectively. The mean difference from MPAPRHCand limits of agreement were -1.5 mmHg and -19.6 to 16.5 mmHg for MPAPTR, and -4.6 mmHg and -24.5 to 15.2 mmHg for MPAPChemla. Accuracy within 10 mmHg and 5 mmHg of MPAPRHCwas 80.4% and 46.4% for MPAPTR, and 71.4% and 48.2% for MPAPChemla, respectively. CONCLUSIONS: MPAPTRand MPAPChemlaare reliable estimates for MPAPRHCin patients with CTEPH. (Circ J 2016; 80: 1259-1264).

Reduced axonal localization of a Caps2 splice variant impairs axonal release of BDNF and causes autistic-like behavior in mice.

Ca(2)(+)-dependent activator protein for secretion 2 (CAPS2 or CADPS2) potently promotes the release of brain-derived neurotrophic factor (BDNF). A rare splicing form of CAPS2 with deletion of exon3 (dex3) was identified to be overrepresented in some patients with autism. Here, we generated Caps2-dex3 mice and verified a severe impairment in axonal Caps2-dex3 localization, contributing to a reduction in BDNF release from axons. In addition, circuit connectivity, measured by spine and interneuron density, was diminished globally. The collective effect of reduced axonal BDNF release during development was a striking and selective repertoire of deficits in social- and anxiety-related behaviors. Together, these findings represent a unique mouse model of a molecular mechanism linking BDNF-mediated coordination of brain development to autism-related behaviors and patient genotype.

[A case of esophageal and intestinal tuberculosis that occurred during treatment of rheumatoid arthritis with etanercept].

An 88-year-old woman with rheumatoid arthritis who had started etanercept treatment in July 2011 was referred to our hospital in February 2012 for right-sided pleural effusion. Chest computed tomography showed right pleural effusion, partial swelling of a calcified mediastinal lymph node, and mid-esophageal thickening of the mucosal wall. Gastroendoscopy showed mid-esophageal ulceration. Histological examination of biopsy specimens from this ulceration revealed noncaseating granulomas with Langhans giant cells. Ziehl-Neelsen staining of this section was positive for acid-fast bacilli. Polymerase chain reaction analysis of gastric juice was positive for Mycobacterium tuberculosis; we therefore diagnosed the patient with esophageal tuberculosis. However, since abdominal computed tomography showed swelling of mesenteric lymph nodes, we also suspected intestinal tuberculosis. Colonoscopy showed multiple ileal erosions; histological analyses of biopsied specimens revealed granulomas with Langhans giant cells, similar to the esophageal findings. We finally diagnosed the patient with both esophageal and intestinal tuberculosis. After anti-tuberculosis treatment, the right pleural effusion disappeared and the abdominal lesions improved. Although mycobacterial involvement of both the esophagus and intestine is rare in immunocompromised and immunocompetent hosts, differential diagnosis of these diseases is likely to become more important.

Infected Walled-Off Necrosis Following COVID-19-Associated Acute Pancreatitis.

A 54-year-old man was admitted for fever and dyspnea. He presented with severe COVID-19 pneumonia and elevated amylase and lipase levels. He received treatment for COVID-19 and possible acute pancreatitis (AP). Although pneumonia and amylase levels improved, a high-grade fever persisted. On day 39, abdominal CT revealed heterogenous liquid and non-liquid components with a well-defined wall around the pancreas, and he was diagnosed with infected walled-off necrosis (WON) after AP. It was concluded to be associated with COVID-19 because there were no identifiable causes, such as alcohol consumption, gallstones, or other viral infections. The necrotic collection and fever improved after endoscopic transgastric drainage and necrosectomy. SARS-CoV-2 is becoming recognized as a new etiological infectious factor for AP, and COVID-19-associated AP shows higher severity and mortality. Clinicians should evaluate COVID-19 patients for concomitant AP, and if it is present, they should carefully monitor the development of local complications, including WON.

Slitrk4 is required for the development of inhibitory neurons in the fear memory circuit of the lateral amygdala.

The Slitrk family consists of six synaptic adhesion molecules, some of which are associated with neuropsychiatric disorders. In this study, we aimed to investigate the physiological role of Slitrk4 by analyzing Slitrk4 knockout (KO) mice. The Slitrk4 protein was widely detected in the brain and was abundant in the olfactory bulb and amygdala. In a systematic behavioral analysis, male Slitrk4 KO mice exhibited an enhanced fear memory acquisition in a cued test for classical fear conditioning, and social behavior deficits in reciprocal social interaction tests. In an electrophysiological analysis using amygdala slices, Slitrk4 KO mice showed enhanced long-term potentiation in the thalamo-amygdala afferents and reduced feedback inhibition. In the molecular marker analysis of Slitrk4 KO brains, the number of calretinin (CR)-positive interneurons was decreased in the anterior part of the lateral amygdala nuclei at the adult stage. In in vitro experiments for neuronal differentiation, Slitrk4-deficient embryonic stem cells were defective in inducing GABAergic interneurons with an altered response to sonic hedgehog signaling activation that was involved in the generation of GABAergic interneuron subsets. These results indicate that Slitrk4 function is related to the development of inhibitory neurons in the fear memory circuit and would contribute to a better understanding of osttraumatic stress disorder, in which an altered expression of Slitrk4 has been reported.

Prognostic significance of body mass index and weight loss in patients with idiopathic pleuroparenchymal fibroelastosis.

BACKGROUND AND AIM: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare form of idiopathic interstitial pneumonias; its physical characteristics include a slender build with platythorax and progressive weight loss. However, the clinical significance of body mass index (BMI) and weight loss remains unclear in patients with IPPFE. Therefore, we aimed to clarify the association between baseline BMI, weight loss after diagnosis, and the prognosis of patients with IPPFE. METHODS: This retrospective study included 71 patients diagnosed with IPPFE at our institution between 2005-2021. BMI at diagnosis was classified into three: underweight (<18.5 kg/m2), normal weight (≥18.5 to <25.0 kg/m2), or overweight (≥25.0 kg/m2). An annual rate of weight change after the diagnosis was evaluated, and ≥5% per year decrease was defined as a significant weight loss. We investigated clinical features and prognosis based on baseline BMI and weight loss. RESULTS: Of the 71 patients, 48 (67.6%) and 23 (32.4%) were classified as underweight and normal weight, respectively, and none were overweight. Significant weight loss occurred in 24 (33.8%) patients, and they tended to have more cases of dyspnea and had significantly older age, lower BMI, higher rates of co-existence of lower-lobe interstitial lung disease, lower pulmonary function test results and higher incidence of pneumothorax after the diagnosis than those without weight loss. Patients with BMI <18.5 kg/m2 and those with weight loss had a significantly worse prognosis than those with BMI ≥18.5 kg/m2 or those without weight loss, respectively (p=0.005, p<0.001). Multivariate analysis revealed that low BMI and weight loss were independent poor prognostic factors. CONCLUSIONS: Low BMI and weight loss are associated with poor prognosis in patients with IPPFE.

An Adult Case of Idiopathic Pulmonary Hemosiderosis Associated with Pulmonary Fibrosis and Emphysematous Change.

A 48-year-old woman was admitted to our hospital with acute respiratory failure. Chest computed tomography showed ground-glass opacity and patchy emphysematous lesions in both lungs. Corticosteroid therapy was effective; however, the disease worsened with the tapering of corticosteroids. Bronchoalveolar lavage revealed hemosiderin-laden macrophages, and video-assisted thoracic surgery showed diffuse interstitial fibrosis with diffuse alveolar hemorrhage (DAH). There was no evidence of vasculitis nor autoimmune diseases. This patient was diagnosed with idiopathic pulmonary hemosiderosis (IPH) that progressed to end-stage pulmonary fibrosis despite treatment. Autopsy demonstrated DAH with pulmonary fibrosis and emphysematous change, suggesting IPH-related pulmonary lesions.

Intra-abdominal Hemorrhage Due to Splenic Vein Aneurysm Rupture Caused by Invasive Aspergillosis during Treatment for Advanced Non-small-cell Lung Cancer.

A 71-year-old man was admitted for left-sided chest pain. He had a history of diabetes, treatment with epidermal growth factor receptor-tyrosine kinase inhibitor for advanced non-small-cell lung cancer, and corticosteroid treatment for underlying lung diseases. Chest computed tomography showed consolidations in the bilateral lower lobes, and Aspergillus fumigatus was detected by bronchoscopy. Invasive pulmonary aspergillosis was suspected, and antifungal therapy with voriconazole was initiated; however, the patient passed away suddenly. Autopsy revealed disseminated Aspergillus infection and intra-abdominal hemorrhage due to the rupture of a splenic vein aneurysm caused by Aspergillus necrotizing vasculitis, which was considered the cause of death.

Bronchiolitis obliterans syndrome associated with an immune checkpoint inhibitor in a patient with non-small cell lung cancer.

A 75-year-old woman was admitted to our hospital with progressive dyspnea 7 months after second-line treatment with pembrolizumab for advanced non-small cell lung cancer. Chest radiography revealed hyperinflation in both lung fields, and pulmonary function tests revealed severe obstructive dysfunction without bronchodilator reversibility. There were no identifiable causes such as infections or autoimmune diseases. Therefore, bronchiolitis obliterans syndrome associated with immune checkpoint inhibitors was clinically diagnosed. Pembrolizumab was discontinued, but the respiratory dysfunction was irreversible and resulted in death. Bronchiolitis obliterans syndrome is an extremely rare but potentially severe adverse event associated with immune checkpoint inhibitor-related lung disease.

Clinical features of idiopathic pleuroparenchymal fibroelastosis with progressive phenotype showing a decline in forced vital capacity.

BACKGROUND: Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is heterogeneous, with some patients showing a progressive decline in forced vital capacity (FVC). However, the clinical features of these cases with progressive phenotypes remain unknown. METHODS: This retrospective study included 48 patients diagnosed with IPPFE who underwent longitudinal pulmonary function tests at our institution from 2005 to 2021. The progressive phenotype was defined as a relative decline of ≥10% in %FVC within two years from diagnosis of IPPFE, and its clinical features were evaluated. RESULTS: Of the 48 patients, 23 (47.9%) were classified as progressive IPPFE. They were significantly older with a higher rate of dyspnea, fine crackles on chest auscultation, lower-lobe usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography, and lower %FVC at diagnosis than non-progressive IPPFE. Additionally, progressive IPPFE had a significantly higher rate of long-term oxygen therapy requirement, the incidence of pneumothorax, and weight loss after diagnosis, which showed worse survival than non-progressive IPPFE. The relative decline in %FVC and weight loss showed a significant positive correlation. Multivariate analysis revealed that lower body mass index tended to predict early progression, and the coexistence of lower-lobe UIP pattern was significantly associated with early progression. A decline in %FVC was an independent poor prognostic factor in IPPFE. CONCLUSIONS: With a progressive decline in %FVC, IPPFE often has an advanced stage at diagnosis and lower-lobe UIP pattern and is associated with weight loss and worse survival.

Targeting Neurons with Functional Oxytocin Receptors: A Novel Set of Simple Knock-In Mouse Lines for Oxytocin Receptor Visualization and Manipulation.

The neuropeptide oxytocin (Oxt) plays important roles in modulating social behaviors. Oxt receptor (Oxtr) is abundantly expressed in the brain and its relationship to socio-behavioral controls has been extensively studied using mouse brains. Several genetic tools to visualize and/or manipulate Oxtr-expressing cells, such as fluorescent reporters and Cre recombinase drivers, have been generated by ES-cell based gene targeting or bacterial artificial chromosome (BAC) transgenesis. However, these mouse lines displayed some differences in their Oxtr expression profiles probably because of the complex context and integrity of their genomic configurations in each line. Here, we apply our sophisticated genome-editing techniques to the Oxtr locus, systematically generating a series of knock-in mouse lines, in which its endogenous transcriptional regulations are intactly preserved and evaluate their expression profiles to ensure the reliability of our new tools. We employ the epitope tagging strategy, with which C-terminally fused tags can be detected by highly specific antibodies, to successfully visualize the Oxtr protein distribution on the neural membrane with super-resolution imaging for the first time. By using T2A self-cleaving peptide sequences, we also induce proper expressions of tdTomato reporter, codon-improved Cre recombinase (iCre), and spatiotemporally inducible Cre-ERT2 in Oxtr-expressing neurons. Electrophysiological recordings from tdTomato-positive cells in the reporter mice support the validity of our tool design. Retro-orbital injections of AAV-PHP.eB vector into the Cre line further enabled visualization of recombinase activities in the appropriate brain regions. Moreover, the first-time Cre-ERT2 line drives Cre-mediated recombination in a spatiotemporally controlled manner on tamoxifen (TMX) administration. These tools thus provide an excellent resource for future functional studies in Oxt-responsive neurons and should prove of broad interest in the field.

Contribution of astrocytic histamine N-methyltransferase to histamine clearance and brain function in mice.

Brain histamine acts as a neurotransmitter in the regulation of various brain activities. Previous studies have shown that histamine N-methyltransferase (HNMT), a histamine-metabolizing enzyme, controls brain histamine concentration and brain function. However, the relative contribution of astrocytic or neuronal HNMT to the regulation of the histaminergic system is still inconclusive. Here, we phenotyped astrocytes-specific HNMT knockout (cKO) mice to clarify the involvement of astrocytic HNMT in histamine clearance and brain function. First, we performed histological examinations using HNMT reporter mice and showed a wide distribution of HNMT in the brain and astrocytic HNMT expression. Then, we created cKO mice by Cre-loxP system and confirmed that HNMT expression in cKO primary astrocytes was robustly decreased. Although total HNMT level in the cortex was not substantially different between control and cKO brains, histamine concentration after histamine release was elevated in cKO cortex. In behavioral tests, impaired motor coordination and lower locomotor activity were observed in the cKO mice. However, anxiety-like behaviors, depression-like behaviors, and memory functions were not altered by astrocytic HNMT disruption. Although sleep analysis demonstrated that the quantity of wakefulness and sleep did not change, the increased power density of delta frequency during wakefulness indicated lower cortical activation in cKO mice. These results demonstrate that astrocytic HNMT contributes to histamine clearance after histamine release in the cortex and plays a role in the regulation of motor coordination, locomotor activity, and vigilance state.

Mice Lacking Cerebellar Cortex and Related Structures Show a Decrease in Slow-Wave Activity With Normal Non-REM Sleep Amount and Sleep Homeostasis.

In addition to the well-known motor control, the cerebellum has recently been implicated in memory, cognition, addiction, and social behavior. Given that the cerebellum contains more neurons than the cerebral cortex and has tight connections to the thalamus and brainstem nuclei, it is possible that the cerebellum also regulates sleep/wakefulness. However, the role of the cerebellum in sleep was unclear, since cerebellar lesion studies inevitably involved massive inflammation in the adjacent brainstem, and sleep changes in lesion studies were not consistent with each other. Here, we examine the role of the cerebellum in sleep and wakefulness using mesencephalon- and rhombomere 1-specific Ptf1a conditional knockout (Ptf1a cKO) mice, which lack the cerebellar cortex and its related structures, and exhibit ataxic gait. Ptf1a cKO mice had similar wake and non-rapid eye movement sleep (NREMS) time as control mice and showed reduced slow wave activity during wakefulness, NREMS and REMS. Ptf1a cKO mice showed a decrease in REMS time during the light phase and had increased NREMS delta power in response to 6 h of sleep deprivation, as did control mice. Ptf1a cKO mice also had similar numbers of sleep spindles and fear memories as control mice. Thus, the cerebellum does not appear to play a major role in sleep-wake control, but may be involved in the generation of slow waves.

Sarcoid-like Granulomatous Lung Disease with Subacute Progression in Silicosis.

A 67-year-old man was admitted to our hospital with cough and fatigue. He had had long-term exposure to silica due to cement processing. Chest computed tomography showed bilateral centrilobular nodules, and hilar and mediastinal lymphadenopathy with calcification, suggesting chronic silicosis. Within a few months, these nodules enlarged, and bilateral patchy consolidations appeared. A lung biopsy revealed sarcoid-like granulomas with birefringent particles under polarized light without malignancy or infection. He was diagnosed with silicosis-associated sarcoid-like granulomatous lung disease, rather than sarcoidosis, according to the clinicopathological findings. His pulmonary manifestations improved after the discontinuation of silica exposure and combination therapy of corticosteroid and azathioprine.

Comparison of clinical utility between digital and analog drainage systems in patients with spontaneous pneumothorax.

BACKGROUND: Digital drainage systems can continuously and numerically monitor air leakage, which may lead to a shorter duration of drainage and hospitalization; however, the usefulness of digital drainage systems compared to that of analog drainage systems for patients with primary or secondary spontaneous pneumothorax remains unclear. METHODS: This retrospective study included 108 patients with spontaneous pneumothorax who were successfully treated with chest drainage alone at our institution. We compared the clinical efficacy of digital and analog chest drainage systems. RESULTS: From the study population, 68 patients were diagnosed with primary and the other 40 with secondary spontaneous pneumothorax. The analog drainage system was used in 44 patients, and the digital drainage system in 64 patients. Among patients with primary spontaneous pneumothorax, the digital group had a significantly shorter duration of chest drainage than the analog group (median 2 vs. 4 days; p = 0.001), but there was no significant difference in those with secondary spontaneous pneumothorax. Additionally, the length and cost of hospitalization in the digital group were significantly lower than those in the analog group for both patients with primary and secondary spontaneous pneumothorax. There was no significant difference in recurrence within 1 week after chest tube removal between the two groups, neither among patients with primary nor among those with secondary pneumothorax. CONCLUSIONS: Digital drainage system may be better than analog drainage system for patients with primary spontaneous pneumothorax who need chest drainage, but further research is needed on drainage system selection for those with secondary disease.