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Biomedical subjects

M A Rashid

Publications and source records attributed to M A Rashid.

At least 37 records · Page 2Linked to original sources
PubMed2001

Absolute stereochemistry and anti-HIV activity of minquartynoic acid, a polyacetylene from Ochanostachys amentacea.

Anti-HIV bioassay-guided fractionation of an organic extract of Ochanostachys amentacea provided an HIV-inhibitory polyacetylenic acid. The identity of this compound was established as (-)-17-hydroxy-9,11,13,15-octadecatetraynoic acid (1), also known as minquartynoic acid, by comparison of its physical and spectral data with previously reported values. Analysis of Mosher's ester derivatives of the methyl ester of 1 allowed assignment of S absolute stereochemistry to the lone chiral center. In an in vitro XTT-based anti-HIV assay, 2-5 micrograms/mL of minquartynoic acid (1) effectively inhibited human lymphoblastoid cell killing by HIV-1.

Alkynes↗
PubMed2001

Cardiovascular injuries associated with sternal fractures.

OBJECTIVE: To find out if the presence of a sternal fracture indicates cardiac and aortic injuries and to clarify the difference between a retrosternal haematoma and widened mediastinum. DESIGN: Retrospective study. SETTING: Teaching hospital, Sweden. SUBJECTS: 418 patients with blunt chest trauma of whom 29 had a fractured sternum (11 with retrosternal haematoma and 18 without) and 389 did not (7 with widened mediastinum and 382 without). MAIN OUTCOME MEASURES: Definitions, risk factors, morbidity, and mortality. RESULTS: Retrosternal haematomas were found adjacent to many fractures and ranged in size from a few mm to 2 cm. They were more common in fractures of the body of sternum. There was no significant difference in the number of associated lesions between patients with sternal fractures with or without a retrosternal haematoma. Conversely, patients with a widened mediastinum had a higher injury severity score, longer hospital stay (p < 0.0001), and more associated lesions (p < 0.05) than those with retrosternal haematomas. Six patients still had pain 1 month after injury of whom two had injury-related long-term disability because of pain. No serious cardiac or aortic injuries were detected in this series. The early mortality in our study was 2/29 in patients with sternal fractures and 1/7 in patients with widened mediastinum. CONCLUSIONS: Sternal fractures are more common than previously reported. An aggressive approach including early operative reduction is recommended even for a stable fracture to reduce the overhelming pain. Sternal fracture with or without retrosternal heamatoma is not a reliable indicator of cardiac and aortic injuries, while mediastinal widening is still a fairly reliable clue that should indicate further investigation.

Adult↗
PubMed2001

Thoracic vascular injuries: a major problem in trauma.

OBJECTIVE: We present a review of our experience in the management of thoracic vascular injuries during the past 10 years in one of Sweden's busiest emergency departments, with morbidity and mortality as the main outcome measures. DESIGN: Of eight patients who sustained chest trauma with thoracic vascular injuries, six presented with shock. Angiography was the gold standard in diagnosing aortic and subclavian injuries. RESULTS: Lesions of the inferior vena cava, left internal mammary artery, and intercostal vessels were detected only at surgery. Two patients died of exsanguination. Managing thoracic vascular injuries is still difficult and challenging for thoracic and trauma surgeons. CONCLUSION: Early thoracotomy is important for salvage of patients with chest-wall vascular injury. Despite our limited experience, which is characteristic for Scandinavian and European countries, our results were satisfactory.

Adult↗
PubMed2000

A sesquiterpene acid and flavonoids from Polygonum viscosum.

4-Isobutyl-6-methyl-5-oxo-3a,4,5,7a-tetrahydro-1H-inden-13-oic acid (named viscosumic acid) and quercetin 3-O-(6"-feruloyl)-beta-D-galactopyranoside, and the known 3',5-dihydroxy-3,4',5',7-tetramethoxyflavone have been isolated from Polygonum viscosum. The structures of these isolates were determined primarily on the basis of extensive 1D and 2D NMR spectral analyses, notably, 13C PENDANT, COSY45, TOCSY, GOESY, NOESY, HMQC and HMBC.

Flavonoids↗
PubMed2000

Antiulcer activity of Mikania cordata.

The alkaloidal fraction obtained from an ethanolic extract of the leaves of Mikania cordata exhibited significant in vivo antiulcer activity in diclofenac sodium-induced gastric erosions in Long Evans rats.

Animals↗
PubMed2000

Haligramides A and B, two new cytotoxic hexapeptides from the marine sponge Haliclona nigra.

Bioassay-guided fractionation of a cytotoxic aqueous extract of the sponge Haliclona nigra provided two new cyclic hexapeptides, haligramides A (1) and B (2), in addition to the known peptide, waiakeamide (3). The structures of peptides 1 and 2 were elucidated by extensive NMR analyses and by comparison of their spectral data with those of waiakeamide (3). The identity of haligramide A (1) was confirmed by its oxidative conversion to waiakeamide (3). Further structural confirmation was provided by oxidation of peptides 1, 2, and 3 to the common bis-sulfone derivative 4.

Animals↗
PubMed2000

HIV-inhibitory cembrane derivatives from a Philippines collection of the soft coral Lobophytum species.

Bioassay-guided fractionation of an aqueous extract of a Philippine Islands collection of the soft coralLobophytum sp. concentrated its HIV-inhibitory activity into fractions rich in cembranoid diterpenes. Lobohedleolide (1), (7Z)-lobohedleolide (2), and a new compound, 17-dimethylaminolobohedleolide (3), were purified from these fractions by HPLC. The structures of compounds 1-3 were elucidated by spectroscopic analyses and by comparison of their spectral data with previously reported values. The relative stereochemistry of the gamma-lactone ring substituents of 3 was determined by 1D NOESY experiments. While several other cembranoids that contain a dimethylamino functional group have been reported from the soft coral Sinularia sp., compound 3 represents the first cembrane diterpene with this functional group isolated from a Lobophytum species. Diterpenoids 1-3 exhibited moderate HIV-inhibitory activity (EC(50) approximately 3-5 microg/mL) in a cell-based in vitro anti-HIV assay.

Animals↗
PubMed2000

Nasimaluns A and B: neo-clerodane diterpenoids from barringtonia racemosa.

An ethanolic extract of the roots of Barringtonia racemosa afforded two novel neo-clerodane-type diterpenoids, methyl-15, 16-epoxy-12-oxo-3,13(16),14-neo-clerodatrien-18, 19-olide-17-carboxylate (nasimalun A, 1) and dimethyl-15,16-epoxy-3, 13(16),14-neo-clerodatrien-17,18-dicarboxylate (17-carboxymethylhardwickiic acid methyl ester, nasimalun B, 2) by NMR and MS analyses and by comparison of their spectral data with related compunds. The relative stereochemistry of the asymmetric centers in 1 and 2 was determined by selective 1D NOESY experiments.

Diterpenes↗
PubMed2000

Cardiac injuries: a ten-year experience.

OBJECTIVE: To present our experience of cardiac injuries treated at one Swedish emergency department in the 10 years 1988-97. DESIGN: Retrospective study. SETTING: Teaching hospital. SUBJECTS: 11 patients (9 men and 2 women, mean age 33 years, range 19-54); in 7 they were penetrating injuries and in 4 blunt. MAIN OUTCOME MEASURES: Morbidity and mortality. RESULTS: The mechanisms of injury were stab wound (n = 7), and car crash, fall, boat crash, and abuse (n = 1 each); drug or alcohol misuse played a part in all those with penetrating injuries. The penetrating wounds involved the left ventricle (n = 3), the right ventricle (n = 2), and the pericardium (n = 2). All 5 patients with ventricular wounds presented with cardiac tamponade, in 1 of whom it was fatal (he bled to death during emergency thoracotomy). The main complications were anoxic brain damage and postpericardiotomy syndrome (1 each). There was no case of myocardial concussion. CONCLUSION: Our data reflect the Swedish experience of heart trauma: there are few cases, alcohol and drug misuse is the principal risk factor, and there were no gunshot wounds.

Adult↗
PubMed2000

Outcome of lung trauma.

OBJECTIVE: To find out whether we could manage critical pulmonary haemorrhages in penetrating injuries, and to report our experience with blunt trauma of the lung. DESIGN: Retrospective study. SETTING: Teaching hospital, Sweden. SUBJECTS: 81 patients who presented with pulmonary injuries during the period January 1988-December 1997; 6 were penetrating and 75 blunt. RESULTS: There was only one patient with an isolated lung contusion. The remaining was divided into 2 groups: those with pulmonary contusion and thoracic lesions (n = 32), and those with pulmonary contusion and extrathoracic lesions (n = 42). Four patients in the penetrating group were shocked and required urgent operations; emergency room thoracotomy (n = 1), urgent thoracotomy (n = 2), and urgent thoracoabdominal exploration (n = 1) were done successfully. We correlated grade of lung injury [American Association for the Surgery of Trauma-Abbreviated Injury Scale (AIS)] with mortality. All patients with penetrating injuries survived without serious consequences. There were a mean (SD), of 6 (2) injuries/patient in those with extrathoracic injuries compared with 3 (1) injuries/patient in the group with thoracic lesions (p < 0.001). The corresponding hospital mortality was 6/42 (19%) mainly as a result of the central nervous system lesions (4/6) compared with 0/32. The mean (SD) Injury Severity Score (ISS) was 9.3 (4.8) in patients with thoracic lesions compared with 24.1 (14.7) in patients with extrathoracic lesions (p < 0.0001), and 14.9 (9.5) in all survivors compared with 49.9 (13.6) among those who died (p < 0.0001). CONCLUSIONS: An excellent outcome can be achieved managing penetrating injuries of the lung by an aggressive approach and urgent surgical intervention even when emergency room thoracotomy is essential. Pulmonary contusion is considered to be a relatively benign lesion that does not add to the morbidity or mortality in patients with blunt chest trauma. These data may help to decrease the obsession with pulmonary contusion in patients with chest trauma, with or without extrathoracic lesions, and avoid many unnecessary computed tomograms of the chest.

Adult↗
PubMed2000

Leukemia inhibitory factor enhances bone formation in calvarial bone defect.

For bone defect reconstruction, locally administered cytokine plasmid was examined. Leukemia inhibitory factor (LIF) can bind to the osteoblast cell surface and induce bone formation both in vitro and in vivo. The authors investigated the local mouse LIF complementary deoxyribonucleic acid (cDNA) plasmid in the pcDNA 3 expression vector, which is promoted by cytomegalovirus and is stabilized by bovine growth hormone polyadenylation, with a gelatin sponge carrier. A total of 150 male Wistar rats were used. They were divided into three groups. Group 1 (N = 30) was treated with the gelatin carrier of the pcDNA 3 vector, group 2 (N = 90) was treated with three different doses of LIF cDNA (0.1, 1, and 10 micrograms) in the pcDNA 3-vector plasmid along with the gelatin carrier, and group 3 (N = 30) was treated with recombinant human bone morphogenetic protein -2. Ten animals in each group were euthanized at 1, 3, and 5 weeks postoperatively. Animals treated with LIF cDNA showed significantly enhanced bone mineral density (p < 0.05), as confirmed by dual-energy X-ray absorptiometry (DEXA), in 3 weeks compared with the control vehicle. By 3 weeks, the number of fibroblast-like cells and collagen fibers decreased, whereas the osteoblast-like cells increased inversely, as revealed during histological examination. LIF messenger ribonucleic acid demonstrated by in situ hybridization was observed most markedly in osteocytes of the LIF cDNA-treated group. Also, LIF peptide was detected in the same cell type by immunohistochemistry. Locally administered LIF cDNA plasmid in a gelatin carrier can increase bone density significantly, with subsequent bone formation, probably via osteocyte activation.

Analysis of Variance↗
PubMed2000

Nomenclature, classification, and signficance of traumatic extrapleural hematoma.

BACKGROUND: Extrapleural hematoma has been found mostly in single case reports as diagnoses with different names. Although huge extrapleural hematoma can cause ventilatory and circulatory disturbances and even death, it has received almost no attention in the literature. Certain basic and modern facts need to be clarified regarding the definition, classification, and significance of extrapleural hematoma in the practice of chest trauma. METHODS: A 10-year retrospective study was undertaken to analyze the incidence, diagnosis, management, morbidity, and mortality of patients with chest trauma and a documented extrapleural hematoma. RESULTS: The incidence of traumatic extrapleural hematoma was 34 of 477, 7.1%. The incidence of thoracic lesions was 86 of 34 = 2.5 lesions per patient, whereas the incidence of extrathoracic lesions was 30 of 34 = 0.9 lesions per patient. Associated rib fractures were found in 30 of 34, 88.2%. More than half of the patients had an associated hemothorax. A thoracotomy was used successfully to remove a huge hematoma in one patient. CONCLUSION: Extrapleural hematoma has been found to be more common than previously reported. Nomenclature and classification are suggested. One of the common injuries to the chest, particularly rib fracture, hemothorax, lung contusion, or pneumothorax might provide the surgeon with a reliable clinical clue that the patient is at inordinate risk to have associated extrapleural hematoma. A formal or mini-thoracotomy is the recommended procedure in cases of huge hematomas.

Adult↗