Characterization of S40-like proteins and their roles in response to environmental cues and leaf senescence in rice.

BACKGROUND: Senescence affects the quality and yield of plants by regulating different traits of plants. A few members of S40 gene family, the barley HvS40 and the Arabidopsis AtS40-3, have been shown to play a role in leaf senescence in Barley and Arabidopsis. Although we previously reported that S40 family exist in most of plants, up to now, no more function of S40 members in plant has been demonstrated. The aim of this study was to provide the senescence related information of S40 gene family in rice as rice is a major crop that feeds about half of the human population in the world. RESULTS: A total of 16 OsS40 genes were identified from the genome database of Oryza sativa L. japonica by bioinformatics analysis. Phylogenetic analysis reveals that the 16 OsS40 proteins are classified into five groups, and 4 of the 16 members belong to group I to which also the HvS40 and AtS40-3 is assigned. S40 genes of rice show high structural similarities, as 13 out of the 16 genes have no intron and the other 3 genes have only 1 or 2 introns. The expression patterns of OsS40 genes were analyzed during natural as well as stress-induced leaf senescence in correspondence with senescence marker genes. We found that 6 of them displayed differential but clearly up-regulated transcript profiles under diverse situations of senescence, including darkness, nitrogen deficiency, hormone treatments as well as pathogen infection. Furthermore, three OsS40 proteins were identified as nuclear located proteins by transient protoplast transformation assay. CONCLUSIONS: Taking all findings together, we concluded that OsS40-1, OsS40-2, OsS40-12 and OsS40-14 genes have potential regulatory function of crosstalk among abiotic, biotic and developmental senescence in rice. Our results provide valuable baseline for functional validation studies of the rice S40 genes in rice leaf senescence.

The Role of the S40 Gene Family in Leaf Senescence.

Senescence affect different traits of plants, such as the ripening of fruit, number, quality and timing of seed maturation. While senescence is induced by age, growth hormones and different environmental stresses, a highly organized genetic mechanism related to substantial changes in gene expression regulates the process. Only a few genes associated to senescence have been identified in crop plants despite the vital significance of senescence for crop yield. The S40 gene family has been shown to play a role in leaf senescence. The barley HvS40 gene is one of the senescence marker genes which shows expression during age-dependent as well as dark-induced senescence. Like barley HvS40, the Arabidopsis AtS40-3 gene is also induced during natural senescence as well as in response to treatment with abscisic acid, salicylic acid, darkness and pathogen attack. It is speculated that rice OsS40 has a similar function in the leaf senescence of rice.

Surgical site infection and pattern of antibiotic use in a tertiary care hospital in Peshawar.

BACKGROUND: Surgical site infection (SSI) is most common complication following surgical procedures. The objective of the study was to collect information on SSI regarding the most frequent pathogen in cases operated in casualty of Lady Reading Hospital (LRH) Peshawar, and sensitivity of the isolated pathogens to different antibiotics used. METHODS: The study was carried out at surgical 'B' unit (SBU) LRH from Jan 1, 2009 till Dec 31, 2009. A total of 100 patients who developed SSI after being operated for peritonitis following traumatic gut perforations, perforated appendix and enteric perforation. The patients included presented to casualty, operated in casualty OT and were shifted to the SBU, LRH. Children and patients operated on the elective list were excluded. Data was collected on specially designed proforma. Demographic details, details of SSI, culture/sensitivity reports and antibiotic used for prophylaxis and after C/S report were recorded. RESULTS: Out of a total of 100, 72 had superficial, 20 had organ/space and 8 had deep SSI. Organisms were isolated in 77 cases (77%). E. coli being most common pathogen (46%), followed by Pseudomonas (23%), mixed growth of Staph. Aureus or MRSA (13%), MRSA (5%) AND Staph aureus (4%) in descending order. No growth was reported in 23% of cases. CONCLUSION: E. coli was the most common organism involved in SSI in SBU LRH. The incidence of infection with MRSA in our unit is high. Combination of antibiotics like pipreacillin/Tazobactam, Cefoperazone/Sulbactam, were most effective against the isolated organisms. except MRSA where Linezolid, vancomycin and Tiecoplanin were effective.

Accuracy of computerised tomography in diagnosis of brain tumours in children.

BACKGROUND: CT scan has replaced most of the invasive techniques in diagnosis of brain tumours because it can accurately demonstrate, localize and characterize the brain tumours. The objective of this study was to observe the accuracy of CT scan in the diagnosis of brain tumours in children by comparing it with histopathology. This descriptive case series was conducted at Department of Radiology, Ayub Teaching Hospital Abbottabad from 10th March 2005 to 9th March 2007. METHODS: Both pre and post contrast CT scan was carried out on 120 patients referred to Radiology Department for CT scan suspected of having brain tumours. Data of CT findings/diagnosis of patients having brain tumours were collected on a proforma. Histopathology of specimen from operation or biopsy was carried out and compared with the CT scan diagnosis. RESULTS: Glial tumours comprised the largest category 68 (56.67%). Medulloblastoma was 23 (19.16%) Craniopharyngioma 8 (6.63%) and Ependymoma were 6 (5.09%) each. Hemangioblastoma 2 (1.67%), Choroid plexus one (0.83%) adenoma and pineal tumours were 9 (3.33%) each. As regards comparison between CT and histopathology, an agreement between the two was found in 104 (86.67%) cases whereas in 16 (13.33%) of the cases, the histopathology reports were different. In case of Astrocytomas 63 (92.64%) were confirmed on histopathology and 5 (7.36%) was reported differently. In Medulloblastomas 19 (82.60%) were accurately diagnosed on CT scan. Sensitivity of CT scan in diagnosis of brain tumours in children was 93.33%. CONCLUSION: CT Scan is more accurate predictor of brain tumour yet it is not always 100% accurate.

Audit of appropriateness and outcome of computed tomography brain scanning for headaches in paediatric age group.

BACKGROUND: Headache is a common complaint in children. With the proliferation of brain imaging centers and the increasing patient demand for CT or MRI studies, brain imaging has become widely used to evaluate headache and exclude malignant lesion. The objectives of this descriptive study were to assess the appropriateness and outcomes of computed tomography brain scanning for headaches in paediatric age group. This study was conducted at the Radiology Department Hayatabad Medical Complex, Peshawar over a period of 1 year July 2008-July 2009. METHODS: Both genders between the ages of 4-18 years included in the study presenting with headache either isolated or common/classic migraine were included in this study. These variants of headache were allocated an appropriateness rating of 2 for CT scan by the American College of Radiology Appropriateness Criteria (ACRAC) for children with headaches. RESULTS: Out of the 100 patients only 4% patients showed abnormal findings on CT scan while the remaining 96% of the scans were absolutely normal. The four patients with abnormal findings all had sinusitis no notorious lesions. CONCLUSION: This audit suggests that a proportion of the computed tomography studies performed for children with isolated headaches or common/classic migraine may have been inappropriate. The development of a local guideline for imaging referral is indicated.

Temporomandibular joint ankylosis: experience with interpositional gap arthroplasty at Ayub Medical College Abbottabad.

BACKGROUND: Satisfactory surgical correction of temporomandibular joint ankylosis (TMA) is limited by a high recurrence rate, particularly in patients who underwent surgery without use of interpositional material. The present study describes our experience of Interpositional Gap Arthroplasty in patients presenting with primary or recurrent TMA. METHODS: The study was conducted on 12 patients presenting at the Oral and Maxillo-Facial Surgical Unit of the Ayub Medical College Abbottabad from 1999 to 2004. Interpositioning materials used included Temporalis fascia, Temporalis muscle, Silastic sheet and Cartilage (Costochondral) graft. Pre- and Postoperative assessment of temporomandibular joint (TMJ) mobility was done by clinical assessment of jaw movement and measurement of interincisal distance by vernier calipers; X-rays were done to document complications such as fibrosis and ankylosis. RESULTS: Nine of the 12 patients (75%) were new cases of ankylosis, while the remaining 3 (25%) had one, three and four prior operations. Duration of ankylosis ranged from 9 months to 12 years. Ankylosis was bilateral in 8 cases (66.7%) and unilateral in 4 cases (33.3%). Operative findings were simple bony ankylosis in 13/20 jaws (65%), soft tissue fibrosis in 4/20 jaws (20%) and massive bony growth in 3/20 jaws (15%). Preoperative interincisal distances ranged from 0-15mm; immediate postoperative distances ranged from 20-40 mm; one-month and six-month postoperative distances ranged from 25-50 mm. All patients had an uncomplicated outcome till six months follow up; one patient developed reduced mouth opening to 12 mm at one year follow up due to parental noncompliance with mouth exercises; one patient developed infection and extrusion of silastic sheet at 2.5 years follow up. CONCLUSION: Interpositional Gap Arthroplasty is a highly effective and safe surgical management option for TMA with acceptable immediate and long term outcome, particularly when temporalis fascia and muscle are used for adults and costochondral grafts with fascia interposition used for children.