Genome sequencing of Streptomyces aureofaciens DM-1 and analysis of 6-demethylchlortetracycline biosynthesis gene cluster / 生物工程学报

Streptomyces aureofaciens DM-1 is a high-yielding 6-demethylchlortetracycline producer. The genome sequencing of DM-1 reveals a linear chromosome containing 6 824 334 bps nucleotides with GC content of 72.6%. In this genome, a total of 6 431 open reading frames were predicted by using glimmer 3.02, Genemark and Z-Curve softwares. Twenty-eight secondary metabolite biosynthetic gene clusters were uncovered by using AntiSMASH gene prediction software, including the complete 6-demethylchlortetracycline biosynthetic gene cluster. A frame-shift mutation in methyltransferase coding region was detected, which may result in the demethylation of chlortetracycline. The complete genome sequence of S. aureofaciens DM-1 provides basic information for functional genomics studies and selection of high-yielding strains for 6-demethylchlortetracycline.

Assessment of the interappointment pain by using two different intracanal medicaments

The objective of this study was to assess the interappointment pain by using two different intracanal medicaments. Comparative study in the department of operative dentistry, Liaquat Medical University Hospital Hyderabad was carried out. 60 teeth either anterior or posterior of male and female patients of 14 to 60 years age diagnosed for root canal treatment were included. Following the routine access cavity preparation, canals were located with endodontic explorer. Working length was taken with 15# k-file, and then instrumentation was performed with proTaper hand files and shaping by the crown down technique along with irrigation by using Milton's [l%Naocl] solution. Canals were dried with paper points and Ledermix paste in Group I and Calcium hydroxide in Group II patients were inserted in random sequence. The patients were recalled, to record the degree of pain on the next day, third day and one week and for clinical evaluation and obturation if the tooth was asymptomatic. Out of 60 cases, 33[55%] were male and 27[45%] were female. Post operative next day, mild pain was observed in 25% [15/60] patients and moderate pain in 20% [12/60] while severe pain in 13.3% [8/60] patients. Similarly on third day, mild pain was observed in 3.3% [2/60] only. While after one week mild pain was found in only 1.6% [1/60] case. Severity of pain was significantly low in group I than group II [p=0.999] after one week. Treatment with Ledermix was significantly better than with Calcium hydroxide in controlling severity of interappointment pain

Management of Chronic Asymptomatic Hyponatremia / 대한내과학회지

Hyponatremia is a common clinical problem in hospitalized patients and nursing home residents. It may also occur in healthy athletes after endurance exercise. The majority of patients with hyponatremia are asymptomatic and do not require immediate correction of the hyponatremia. While mild hyponatremia has traditionally been considered benign, symptomatic hyponatremia is a medical emergency requiring rapid correction to prevent the worsening of brain edema. However, it has been suggested that mild hyponatremia may be associated with gait disturbance, attention deficits, and an increased risk of falls, which may result in fracture, and its presence predicts a poor prognosis. The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is among the most frequent causes of chronic hyponatremia. Hyponatremia must be corrected slowly (<10~12 mmol/L within the first 24 h, and <18 mmol/L within the first 48 h) to avoid osmotic myelinolysis. Fluid restriction and demeclocycline are the treatments for chronic hyponatremia used most widely. However, fluid restriction is of limited use because of poor long-term compliance and demeclocycline lacks broad availability. In controlled clinical trials vaptans (a vasopressin receptor antagonist) was efficacious in mild to moderate SIADH with an acceptable safety profile. However, its long-term use is currently impractical and more data are needed.

The Effect of Demeclocycline on the Management of Syndrome of Inappropriate Secretion of Antidiuretic Hormone in Brain Injured Patient

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a frequent complication of severe head trauma. Fluid restriction is treatment choice of SIADH in patients with traumatic brain injury (TBI), but fluid restriction is limited because they need sufficient calories. We described a patient who, on the four months after a head injury, presented with deterioration of consciousness, which coincided with the development of the SIADH, and which rapidly reversed with the correction of the hyponatremia by demeclocycline with minimal fluid restriction. We suggest that SIADH should be included in the differential diagnosis of deterioration of consciousness during the recovery period of the patients suffering from head injury because unexpected clinical deterioration may often have a reVersible cause. Also, demeclocycline will be useful, which allows for increased fluid liberalization and for provision of adequate calories, in the treatment of the SIADH in patients with TBI.

A case of syndrome of inappropriate antidiuretic hormone secretion (SIADH) in small cell cancer of lung combined with squamous cell cancer of lung / 대한내과학회지

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the term applied to arginine vasopressin (AVP) excess associated with hyponatremia without edema in the absence of physiologic or pharmacologic stimuli to AVP secretion. SIADH is associated with various conditions such as malignant tumors, infection, central nervous system disorders, and different pharmacological agents. The patient was 73-year-old female. She was admitted to the hospital because of persistent cough, dizziness, general weakness and confusion. On admission, her serum osmolality was 253 mOsm/kg, urine osmolality was 416 mOm/kg, and urine Na concentration was 159 mEq/L. Her Chest X-ray and CT scan of lung showed about 4x3.5 cm sized mass at posterior basal segment of left lower lobe of the lung, and CT-guided percutaneous needle aspiration revealed small round cell with clusters of malignant squamous cells. She was treated by salt restriction, hypertonic saline infusion and demeclocycline. We planned chemotherapy for advanced combined lung cancer, but she was discharged because of poor general condition and associated pneumonia without cancer chemotherapy. We report a rare case of SIADH in small cell cancer of lung combined with squamous cell cancer of lung.

A Case of SIADH Related to Drug-indeced Generalized Maculopapular Rash / 대한내분비학회지

Syndrome of inappropriate antidiutetic hormone(SIADH) secretion is the most common cause of hyponatremia in clinical medicine. Before diagnosis of the SIADH is made, other causes for a decreased diluting capacity and nonosmotic stimuli for AVP release need to be rule out. Disorders associated with SIADH can be divided into 4 major etiologic groups: malignancies, pulmonary diseases, central nervous disorders, and drugs. A 45-year-old woman was admitted due to maculopapular skin eruption and fever after taking medications for fever and myalgia. Generalized tonic clonic seizure was developed nine days later, and laboratory results showed marked hyponatremia. During the evaluation, treatment, and subsequent follow-up, the diagnosis of SIADH was confirmed, but the definitive cause was obscure. With fluid restriction, sodium replacement and demeclocycline therapy, she recovered completely 6 months later. We suggest that the SIADH might be related to drug-induced generalized maculopapular rash via menmgitis-like reaction in CSF as one of systemic adverse side effects to drugs rather than direct effect of related drugs.

An experimental study on the effect of the demethylchlortetracycline on mandibular symphysis in rats / 대한치과교정학회지

This study was undertaken to assess the effects of demethylchortetracycline of bone growth of mandibular symphyseal region in rats. Demethylchlortetracycline at 30mg/kg body weight, respectively, were daily administered by mouth to the seven female rats from 10th day pregnancy to 13th day. Thirty six new-born rats from these experimental animals were used for histological examination at 1, 5, 10, 15, 20, 25 and 30 days. All these new-bone rats were killed by an overdose of ether. Mandivular bodies were removed and fixed in 10% neutral formalin, Carnoy and aceton. Specimens were embedded, sectioned and stained with H-E, Van Gieson, PAS and prepared for alkaline phosphatase. The results were as follows; 1. Until erupting of incisors, hyaline cartilage was located in relatively large symphyseal space, but bone trabeculae of ossifying area at incisal were arranged irregularly in experimental group. 2. During this period, PAS reaction was moderately positie, but alkaline phosphatase reaction was slightly positive. 3. By erupting or incisors, symphyseal space appeared narrower like control group, but alkaline phosphatase reaction tended to slow down. 4. By erupting of molars, symphyseal space appeared much narrower, and cartilage plate was reduced and sealed off like control group. Alkaline phosphatase reaction tended to slow down severely.