Nazolabiální cysta (NC), známá také jako Klestadtova cysta, je vzácná neodontogenní cystická leze měkkých tkání maxilofaciální oblasti, která predominantně postihuje ženy ve středním věku. Typicky bývá asymptomatická, může ale způsobovat otok v nazolabiální oblasti nebo nosní obturaci. Prezentované kazuistiky popisují případy dvou pacientek, kterým byla NC diagnostikována, ale každá podstoupila jiný typ operačního výkonu, nicméně s dobrým klinickým výsledkem v obou případech, kdy jsou obě bez obtíží a recidivy. Léze byla poprvé popsána v roce 1882 a později zkoumána Walterem Klestadtem v roce 1953. Diagnóza se obvykle provádí pomocí CT a MR, s chirurgickou excizí jako preferovanou metodou léčby. Recidiva po operaci je vzácná a prognóza velmi příznivá.

Nasolabial cyst (NC), also known as Klestadt‘s cyst, a is a rare non-odontogenic cystic lesion of the soft tissues in the maxillofacial area, predominantly affecting middle-aged women. It typically presents asymptomatically but can cause swelling in the nasolabial region or nasal obstruction. Case reports describe two patients diagnosed with NC who underwent different types of surgical procedures, both resulting in good clinical outcomes, with both patients remaining symptom-free and without recurrence. The lesion was first described in 1882 and later studied by Walter Klestadt in 1953. Dia gnosis is typically performed using CT and MRI, with surgical excision being the preferred method of treatment. Recurrence after surgery is rare, and the prognosis is very favourable.

• Keywords
• Klestadtova cysta,
• MeSH
• Cysts surgery   diagnosis   classification   MeSH
• Diagnosis, Differential MeSH
• Adult MeSH
• Nonodontogenic Cysts * surgery   diagnostic imaging   diagnosis   classification   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Imaging methods   MeSH
• Nasal Obstruction diagnosis   etiology   MeSH
• Otorhinolaryngologic Surgical Procedures methods   MeSH
• Tomography, X-Ray Computed methods   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

Souhrn Úvod: Lumbální kýla v dětském věku je extrémně vzácná diagnóza a vyžaduje specifický diagnostický a léčebný přístup. Kazuistika prezentuje první popsaný případ v České republice. Popis případu: Dvacetidvouměsíční chlapec byl vyšetřen na chirurgické ambulanci pro měkkou, volně reponibilní rezistenci v pravé bederní oblasti, která byla dle matky přítomna od narození. Ultrazvukové vyšetření prokázalo defekt v oblasti odpovídající trigonum lumbale superius (Grynfeltti seu Lesshafti) velikosti 17 × 11 mm s herniací střevní kličky. Chlapec podstoupil RTG skeletu a ultrazvuk břicha k vyloučení přidružených vad a následně byl indikován k otevřené hernioplastice. Vzhledem k velikosti defektu byla zvolena primární plastika bez použití síťky. Pooperační průběh byl bez komplikací a při plánovaných kontrolách byl pacient bez známek recidivy kýly a bez vývojové asymetrie. Závěr: Lumbální kýla u dětí je vrozená a často se objevuje v souvislosti s dalšími přidruženými malformacemi, které je nutné vyloučit. Typ operace závisí na velikosti defektu a cílem je zajistit plastiku bez napětí.

Summary Introduction: Lumbar hernia in the pediatric population is an extremely rare diagnosis and therefore requires specific diagnostic and therapeutic approaches. This case report describes the first published case of a pediatric lumbar hernia in the Czech Republic. Case description: A 22-month-old boy was examined at a pediatric surgical clinic due to a soft reducible mass in the right lumbar region, which, according to his mother, has been present from birth. An ultrasound scan confirmed a defect in the anatomical localization of the superior lumbar triangle (the triangle of Grynfeltt-Lesshaft) measuring 17 × 11 mm with a bowel loop herniation. The patient underwent a skeletal X-ray and an abdominal ultrasound in order to rule out associated malformations, following which he was scheduled for an open hernioplasty. Given the small size of the defect, a primary closure without mesh hernioplasty was performed. The postoperative course was uneventful and at clinical follow-ups the patient showed no signs of hernia recurrence or growth asymmetry. Conclusion: Lumbar hernia in children is congenital and frequently occurs with other associated malformations, which must be ruled out. The type of operation depends on the size of the defect and its purpose is to provide a tension-free closure.

• Keywords
• lumbální kýla,
• MeSH
• Hernia * diagnosis   pathology   MeSH
• Infant MeSH
• Humans MeSH
• Herniorrhaphy methods   MeSH
• Congenital Abnormalities MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Male MeSH
• Publication type
• Case Reports MeSH

Osteoartróza je multifaktoriáloní onemocnění, které postihuje velkou část populace. Uvádí se, že obraz osteoartrózy je při RTG vyšetření viditelný až u 60 % vyšetřovaných osob nad 65 let. Jedná se o jednu z nejčastějších příčin nemocnosti. Osteoartróza je až ve 20 % důvodem návštěvy ordinace praktického lékaře. U mladších osob může být příčinou vzniku invalidity. Jde o multifaktoriální degenerativní onemocnění kloubů, při kterém dochází k poruše obnovy kloubní chrupavky. Kloubní chrupavka ztrácí lesk, měkne a na jejím povrchu vznikají fisury. Postupně se stává chrupavka méně odolnou a dochází k jejím ztrátám. Subchondrální kost sklerotizuje a na okrajích kloubu se tvoří osteofyty. Druhotně jsou postiženy okolní měkké tkáně, zejména vazy. Osteoartróza kolenního kloubu (gonartróza) může postihovat mediální, laterální femorotibiální nebo femoropatelární oblast. Způsobuje bolest, typicky na začátku pohybu, bolest se stupňuje a je ovlivňována počasím. Pohyb je omezený a často jsou viditelné osové deformity. Rozlišujeme čtyři stupně gonartrózy dle RTG nálezu. Léčba zahrnuje režimová opatření, farmakoterapii a chirurgickou léčbu. Z analgetik lze použít nesteroidní antiflogistika, ostatní neopioidní a případně i opioidní analgetika. Často nejúčinnější je léčba nesteroidními antiflogistiky, které potlačují zánětlivou komponentu procesu. Vhodným zástupcem ze skupiny analgetik s protizánětlivými účinky je aceklofenak, preferenčně působící na COX-2 (1). Užívá se perorálně, rychle se absorbuje a jeho biologická dostupnost je téměř 100 % (2). Aceklofenak je dobře tolerován, je šetrnější pro GIT ve srovnání s většinou NSAIDs (3, 4). Kazuistika ilustruje postup léčby u polymorbidní pacientky s gonatrózou a chronickým vertebrogenním algickým syndromem lumbálního úseku páteře.

Osteoarthritis is a multifactorial disease that affects a large portion of the population. It is reported that the image of osteoarthritis is visible in X-ray examinations in up to 60% of examined individuals over 65. It is one of the most common causes of morbidity. Osteoarthritis accounts for up to 20% of visits to a general practitioner's office. In younger individuals, it can be a cause of disability. It is a multifactorial degenerative joint disease in which there is a disruption in the renewal of joint cartilage. The joint cartilage loses its luster, softens, and fissures form on its surface. Gradually, the cartilage becomes less resilient and losses occur. The subchondral bone becomes sclerotic, and osteophytes form at the edges of the joint. Secondarily, surrounding soft tissues, especially ligaments, are affected. Knee osteoarthritis (gonarthrosis) can affect the medial, lateral femorotibial, or femoropatellar area. It causes pain, typically at the beginning of movement, the pain intensifies and is influenced by the weather. Movement is limited, and axial deformities are often visible. We distinguish four degrees of gonarthrosis based on X-ray findings. Treatment includes regimen measures, pharmacotherapy, and surgical treatment. Analgesics such as nonsteroidal anti-inflammatory drugs (NSAIDs), other non-opioid, and possibly opioid analgesics can be used. The most effective treatment is often with NSAIDs, which suppress the inflammatory component of the process. A suitable representative from the group of analgesics with anti-inflammatory effects is aceclofenac, which preferentially acts on COX-2. It is taken orally, quickly absorbed, and its bioavailability is almost 100%. Aceclofenac is well tolerated and is gentler on the gastrointestinal tract compared to most NSAIDs. The case study illustrates the treatment procedure for a poly morbid patient with gonarthrosis and chronic vertebrogenic algic syndrome of the lumbar spine.

• Keywords
• aceklofenak,
• MeSH
• Anti-Inflammatory Agents, Non-Steroidal administration & dosage   therapeutic use   MeSH
• Osteoarthritis, Knee * drug therapy   pathology   MeSH
• Drug Therapy, Combination MeSH
• Comorbidity * MeSH
• Humans MeSH
• Low Back Pain drug therapy   MeSH
• Analgesics, Opioid MeSH
• Aged MeSH
• Tramadol administration & dosage   therapeutic use   MeSH
• Check Tag
• Humans MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

Prezentujeme kazuistiku 69letého muže, u něhož byl při ultrazvukovém vyšetření urotraktu náhodně zachycen suspektní 30mm útvar v oblasti levé nadledviny, na základě zobrazovacích vyšetření nebylo možné vyloučit maligní potenciál nálezu. Pacient byl indikován k levostranné adrenalektomii, histologickým nálezem byl středně diferencovaný ohraničený leiomyosarkom, nadledvina byla bez infiltrace. Pacient byl bez známek generalizace, na základě doporučení multidisciplinárního onkologického týmu je zařazen do sledování, kontrolní restagingové CT proběhlo šest měsíců od výkonu s negativním nálezem.

We describe a case report of a 69-year-old male with suspicious 30 mm mass in the area of left adrenal gland detected on ultrasound examination. Based on imaging examinations it was not possible to rule out a malignant potential of the lesion. The patient underwent left side adrenalectomy, the histological examination revealed a moderately differentiated, well-circumscribed leiomyosarcom. The adrenal gland was without infiltration. There were no signs of metastatic disease. According to the recommendation of multidisciplinary oncology team, he is placed under surveillance. The patient underwent a follow-up restaging CT 6 months after the surgery with negative results.

• MeSH
• Adrenalectomy methods   MeSH
• Leiomyosarcoma * surgery   diagnosis   pathology   MeSH
• Humans MeSH
• Adrenal Glands pathology   MeSH
• Neoplasms, Connective and Soft Tissue pathology   therapy   MeSH
• Tomography, X-Ray Computed MeSH
• Retroperitoneal Neoplasms surgery   diagnosis   pathology   MeSH
• Aged MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Publication type
• Case Reports MeSH

INTRODUCTION: Shoulder dislocation is very common. However, neglected or chronic shoulder dislocations are extremely rare. The position of the humeral head determines the classification of shoulder dislocation. Anterior shoulder dislocation accounts for most cases, while inferior dislocation is rare. Negligence from the patient and misdiagnosis are the leading causes of chronic shoulder dislocation. Treatment of the condition poses a significant challenge for surgeons since there is no widely accepted treatment protocol. CASE PRESENTATION: A 56-year-old woman presented with a neglected anterior subglenoid dislocation of the shoulder joint. The dislocation occurred due to a cow kick, and initial treatment from a traditional healer and an unqualified health practitioner failed. Clinical examination and X-ray confirmed the dislocation without associated fractures. An initial attempt at closed reduction under sedation was unsuccessful. Subsequently, open reduction and a Latarjet procedure were performed successfully, resulting in a satisfactory outcome. DISCUSSION: Chronic anterior dislocation primarily affects the elderly population. Open reduction and fixation procedures have shown satisfactory outcomes. The choice of treatment depends on several factors, including bone deficiencies, soft tissue damage, and the presence of Hill-Sachs or Bankart lesions. Open reduction and laterjet procedure is a validated treatment. However, early physical therapy contributes to favorable outcomes. CONCLUSION: The condition's rarity makes it difficult to establish a well-accepted treatment protocol. Early and strict rehabilitation protocols will lead to a favorable outcome.

• Publication type
• Journal Article MeSH
• Case Reports MeSH

KEY CLINICAL MESSAGE: In the anatomically complex terrain of the head and neck, the use of 3D intraoperative models serves as an effective verification tool, determining the size, shape, and number of foreign bodies. This allows the main operator to maximize their capacities for careful wound revision and receive real-time information about the remaining content of the sought-after bodies. ABSTRACT: Penetrating foreign bodies of various origins in the head and neck are uncommon, but potentially hazardous injuries. Complete removal of foreign bodies from soft tissues is essential for optimal healing, minimizing complications, and significantly reducing the risk of the need for reoperation. Despite various technological systems and safeguards available, unintentionally retained surgically placed foreign bodies remain difficult to eliminate completely. A 34-year-old female patient with a cut on the right side of her face who was initially treated with sutures at a general surgical clinic presented for a follow-up examination. A foreign body was verified subcutaneously on the anterior-posterior x-ray image on the right side. Computed tomography confirmed a total of 7 foreign bodies with a density corresponding to dental enamel, distributed subcutaneously, subfascially, and intramuscularly in the right temporal region. As part of the preoperative preparation and analysis, the bone segment of the right temporal fossa with the zygomatic bone and the glass fragments were segmented from the CT data and printed on an SLA printer. The physical 3D models were autoclave sterilized and present during surgery. The position, shape, and number of each individual glass fragment was compared with 3D-printed one. The benefits of producing 3D models of foreign bodies are undeniable, particularly in their perioperative comparison with the removed foreign bodies from wounds.

• Publication type
• Journal Article MeSH
• Case Reports MeSH

A 56-year-old female was referred to our service for management of a malignant salivary gland neoplasm with compromised margins that had been biopsied previously at another service. The patient reported a twenty-year history of a lesion in the oral cavity with progressive and exuberant growth over the past two years, associated with local pain and dyspnea. Physical examination revealed an erythematous, ulcerated, and hemorrhagic lesion measuring approximately 3 cm on the left soft palate and tonsillar pillar. Computed tomography revealed an expansile lesion in the topography of the left soft palate, growing predominantly toward the lumen of the nasopharynx and partially invading the left wall of this region. The patient underwent surgery and histopathologic examination revealed an infiltrative and aggressive epithelial neoplasia with large vacuolated and eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli. The neoplastic cells were arranged in a solid, microcystic, tubular, and follicular pattern with eosinophilic luminal secretion. Mitotic figures were frequent and all margins were affected by the neoplasia. Morphologic and immunohistochemical features supported the diagnosis of secretory carcinoma, and the patient is currently being followed for further therapeutic intervention.

• MeSH
• Carcinoma pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Salivary Glands, Minor * pathology   MeSH
• Salivary Gland Neoplasms * pathology   diagnosis   MeSH
• Tomography, X-Ray Computed MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Female MeSH
• Publication type
• Letter MeSH
• Case Reports MeSH

Východiska: Osteosklerotická ložiska detekovaná u pacienta s monoklonální gamapatií znamenají většinou diagnózu syndromu POEMS. Osteosklerotický myelom bez dalších projevů patřících do obrazu syndromu POEMS je naprosto výjimečný nález. Popis případu: U 46leté ženy způsobily osteosklerotické změny temporoparietální oblasti zduření měkkých tkání nad ložiskem a bolest v této oblasti. Biopsie parietální kosti prokázala osteosklerózu s nevelkou klonální plazmocelulární infiltrací. Monoklonální imunoglobulin typu IgG-lambda (podtřídy IgG1) v séru byl v koncentraci 8 g/l. V kostní dřeni byla zjištěna jen nepočetná infiltrace (8 %) atypickými plazmatickými buňkami. Flow-cytometrické vyšetření kostní dřeně detekovalo mezi všemi jadernými buňkami 0,37 % plazmatických buněk, z nichž ale 91 % bylo klonálních s expresí lambda řetězců. V rámci hledání jiných příčin osteosklerózy bylo provedeno FDG-PET/CT vyšetření, které neodhalilo žádnou ložiskovou akumulaci FDG, tedy žádný jiný tumor (karcinom prsu anebo žaludku), který by mohl tyto kostní změny způsobit. Low-dose CT prokázalo nepravidelnou strukturu skeletu mimo kalvu. Jednoznačná osteosklerotická či osteolytická ložiska nebyla na low-dose CT zřetelná. Pro zmapování rozsahu ložisek intenzivní kostní novotvorby následovalo NaF-PET/CT vyšetření, které zviditelnilo mnohočetná ložiska s intenzivní novotvorbou kosti, a tedy i vysokou akumulací fluoridu. MR mozku zjistilo ložiska pachymeningitidy. Pacientka neměla příznaky syndromu POEMS, a tak jsme diagnózu uzavřeli jako monoklonální gamapatie klinického významu (monoclonal gamapathy of clinical significance – MGCS) s osteosklerózou, která se dříve nazývala osteosklerotický mnohočetný myelom. Závěr: MGCS s osteosklerotickými změnami skeletu bez známek syndromu POEMS je extrémně vzácná forma plazmocelulární dyskrazie. Od klasického mnohočetného myelomu se liší indolentním průběhem a příznivější prognózou. Publikace dokumentuje unikátní klinické projevy této nemoci a přínos zobrazení NaF-PET/CT.

Introduction: Multiple myeloma is a common plasma cell neoplasia usually accompanied by the formation of osteolytic foci, whereas osteosclerotic myeloma is a very rare form of plasma cell dyscrasia. When osteosclerotic myeloma is detected, osteosclerotic foci are usually part of the POEMS syndrome. Osteosclerotic myeloma without other manifestations of the POEMS syndrome is an unusual finding. Case description: In a 46-year-old woman, osteosclerotic changes of the temporoparietal region caused soft tissue induration over this lesion, which initiated further investigation. Imaging studies subsequently showed multiple osteosclerotic foci in the skull. Examination of blood proteins revealed 8 g/L of IgG-lambda monoclonal immunoglobulin, subclass IgG1. In search of the cause of the osteosclerotic changes, FDG-PET/CT was performed, which revealed no FDG accumulation, i.e., no other tumor (breast or stomach cancer). Low-dose CT showed irregular bone structure, but not significant osteolytic or osteosclerotic foci. To map the extent of osteosclerotic changes, NaF-PET/CT imagination followed, which revealed multiple spots with high fluoride accumulation. A parietal bone biopsy showed osteosclerosis with minor clonal plasma cell infiltration. Trepanobioptic bone marrow sampling revealed an infiltration of bone marrow with atypical plasma cells in 8%. Flow-cytometric examination of bone marrow showed 0,37% of plasma cells, however predominantly (91%) clonal with lambda expression. MRI of the brain identified asymptomatic meningeal thickening. There was no evidence of POEMS syndrome in the patient; thus, we concluded the diagnosis as monoclonal gammopathy of clinical significance with osteosclerosis which was previously termed osteosclerotic multiple myeloma. Conclusion: Monoclonal gammopathy of clinical significance (MGCS) with osteosclerotic skeletal changes, documented on CT and multiple foci with intensive osteoneogenesis, documented on NaF-PET/CT without evidence of POEMS syndrome, is an extremely rare form of plasma cell dyscrasia. This publication documents the unique clinical manifestations of IgG-lambda type plasma cell proliferation without signs of POEMS syndrome and the role of NaF-PET/CT imaging. Classification of this disease as MGSC with osteosclerotic manifestations is more consistent with the indolent nature of the disease with a significantly better prognosis, compared with multiple myeloma.

• MeSH
• Bone Marrow Cells pathology   MeSH
• Diagnosis, Differential MeSH
• Histological Techniques MeSH
• Hypergammaglobulinemia * diagnosis   complications   pathology   MeSH
• Skeleton diagnostic imaging   pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Osteosclerosis * diagnostic imaging   immunology   complications   pathology   MeSH
• Paraproteinemias diagnosis   complications   pathology   MeSH
• Positron Emission Tomography Computed Tomography MeSH
• Tomography, X-Ray Computed MeSH
• POEMS Syndrome diagnosis   pathology   MeSH
• Parietal Bone pathology   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Female MeSH
• Publication type
• Case Reports MeSH

PURPOSE: The authors evaluated a cohort of 37 patients with histologically verified synovial chondromatosis (SC) between 2013 and 2022. METHODS: The cohort consisted of 37 patients (26 women, 11 men). 36 patients had unilateral involvement, while one patient had bilateral involvement. The average age of the patients was 54.77 years. The authors used the Milgram histopathological classification. They evaluated SC localisation, clinical symptoms, diagnostics and treatment (including recurrence incidence) in this cohort. RESULTS: In 31 patients (83.7%) SC affected only the upper joint space in one patient (2.7%) the lower space, and in five patients (13.6%) both spaces. 12 patients (32%) were Milgram Stage 1 (presence of synovial metaplasia without loose bodies), eight patients (22%) were Stage 2 (presence of synovial changes, loose bodies), and 17 patients (46%) were Stage 3 (presence of loose bodies, no synovial changes). Pain was the dominant clinical symptom (32 patients, 86.4%). Treatment consisted of arthroscopy and open surgery. Two patients underwent primary reconstruction and total TMJ replacement. Treatment was successful in 89.2% of cases (33 patients), with four (10.8%) patients suffering recurrence. CONCLUSION: As this patient cohort shows, pain was the dominant symptom in patients with SC. Magnetic resonance imaging is fundamental in the diagnosis of SC, demonstrating pathological findings even in patients for whom an initial X-ray was negative. These were mainly patients with Milgram Stages 1 and 2 without calcification, loose bodies or pathological changes of the bone structures. This is why the authors recommend MRI for any patient experiencing pain for more than three months, and if this reveals an effusion, joint distension or intraarticular soft tissue mass, they will always indicate arthroscopy. Thorough follow-up of patients is recommended, although SC recurrence is not very frequent. The authors recommend follow-up one, three and six months after surgery, and then annually for the first five years after surgery. They recommend follow-up MRI one, two and five years after surgery.

• MeSH
• Arthroscopy MeSH
• Chondromatosis, Synovial * surgery   pathology   diagnostic imaging   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Temporomandibular Joint Disorders * surgery   pathology   diagnostic imaging   MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Letter MeSH

Tato kazuistika prezentuje vzácný případ 29leté ženy se spontánním pneumomediastinem, která byla ošetřena na urgentním příjmu pro subjektivní pocit dyspnoe, rinitidu a subjektivně udávaný pocit narůstajícího otoku krku. V klinickém obraze dominoval pouze krepitus v oblasti krku a nadklíčků. CT vyšetření krku a hrudníku s popisem masivního emfyzému měkkých tkání krku, hrudníku a obličeje vpravo odhalilo pneumomediastinum dosahující až k bránici. Na základě klinického stavu a zobrazovacího vyšetření, které byly konzultovány s hrudními chirurgy, jsme stav hodnotili jako benigní spontánní pneumomediastinum. Pacientka byla léčena konzervativně a třetí den hospitalizace propuštěna do domácí péče.

This case study presents a rare case of a 29-year-old woman with spontaneous pneumomediastinum who was treated in the emergency department for subjective dyspnea, rhinitis, and a subjectively reported increasing swelling of the throat. The clinical presentation was only characterized by crepitus in the neck and supraclavicular areas. CT scan of the neck and chest revealed massive emphysema of the soft tissues of the neck, chest, the right side of the face, and pneumomediastinum extending to the diaphragm. Based on the clinical presentation and imaging findings, which were consulted with thoracic surgeons, we assessed the condition as benign spontaneous pneumomediastinum. The patient was treated conservatively and discharged from the hospital on the third day of hospitalization with the need of aftercare.

• MeSH
• Adult MeSH
• Conservative Treatment MeSH
• Humans MeSH
• Mediastinal Emphysema * diagnostic imaging   etiology   pathology   therapy   MeSH
• Tomography, X-Ray Computed MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Female MeSH
• Publication type
• Case Reports MeSH