Are Dropped Bone Grafts Safe to be Re-used? - An Experimental Study Comparing Efficacy of Chlorhexidine, Povidone-Iodine and Alcohol.

INTRODUCTION: A dilemma arises when a bone graft or fracture fragment is accidentally dropped on the operation theatre floor and becomes contaminated. This study aimed to determine the efficacy of simple and readily available antiseptic solutions in disinfecting contaminated bones. MATERIAL AND METHODS: This experimental study involved 225 bone specimens prepared from discarded bone fragments during a series of 45 knee and hip arthroplasty surgeries. The bone fragments were cut into five identical cubes and were randomly assigned to either control (positive or negative), or experimental groups (0.5% chlorhexidine, 10% povidone-iodine or 70% alcohol). The control negative was to determine pre-contamination culture. All bone specimens, except the control negative group were uniformly contaminated by dropping on the operation theatre floor. Subsequently, the dropped bone specimens except for the control positive group, were disinfected by immersing in a respective antiseptic solution for 10 minutes, before transported to the microbiology laboratory for incubation. RESULTS: The incidence of a positive culture from a dropped bone fragment was 86.5%. From the 37 specimens sent for each group, the incidence of positive culture was 5.4% (2 specimens) after being disinfected using chlorhexidine, 67.6% (25 specimens) using povidone-iodine and 81.1% (30 specimens) using alcohol. Simple logistic regression analysis demonstrated that chlorhexidine was significantly effective in disinfecting contaminated bones (p-value <0.001, odd ratio 0.009). Povidone-iodine and alcohol were not statistically significant (p-value 0.059 and 0.53, respectively). Organisms identified were Bacillus species and coagulase negative Staphylococcus. No gram-negative bacteria were isolated. CONCLUSION: A total of 0.5% chlorhexidine is effective and superior in disinfecting contaminated bones.

Spectroscopic evidence for origins of size and support effects on selectivity of Cu nanoparticle dehydrogenation catalysts.

Selective dehydrogenation catalysts that produce acetaldehyde from bio-derived ethanol can increase the efficiency of subsequent processes such as C-C coupling over metal oxides to produce 1-butanol or 1,3-butadiene or oxidation to acetic acid. Here, we use in situ X-ray absorption spectroscopy and steady state kinetics experiments to identify Cuδ+ at the perimeter of supported Cu clusters as the active site for esterification and Cu0 surface sites as sites for dehydrogenation. Correlation of dehydrogenation and esterification selectivities to in situ measures of Cu oxidation states show that this relationship holds for Cu clusters over a wide-range of diameters (2-35 nm) and catalyst supports and reveals that dehydrogenation selectivities may be controlled by manipulating either.

Sodium hydrosulphide against renal ischemia/reperfusion and the possible contribution of nitric oxide in adult male Albino rats.

UNLABELLED: This study evaluates the effects produced by H2S donor; sodium hydrosulfide (NaHS), in a renal ischemia/reperfusion (IR) rat model and assesses the possible mediating role of nitric oxide (NO) in these H2S' effects. BACKGROUND: For several centuries, hydrogen sulfide (H2S) had been known to be a highly toxic agent. Recent studies, however, indicated that apart from NO and CO, H2S is the third "gasotransmitter" involved in the regulation of various physiological functions. Nevertheless, its impact on renal IR injury remains unclear. METHODS: Rats were randomly divided into three groups: sham control; renal IR; and renal IR+NaHS groups.NaHS (100 µmol/kg, ip) was administered 30 min prior to the induction of renal ischemia. RESULTS: NaHS was found to attenuate significantly the IR-induced elevations in the serum levels of urea, creatinine and tumor necrosis factor α (TNF-α) as compared with IR group. NaHS also significantly compensated the deficits in the total antioxidant capacities (TAC) and lowered the elevated malondialdehyde (MDA) levels observed with renal IR in renal, hepatic, pulmonary, and cardiac tissues. Furthermore, NaHS pretreatment down-regulated the renal IR-induced over-expression of inducible nitric oxide synthase (iNOS) and up-regulated the IR-induced suppression of endothelial nitric oxide synthase (eNOS). The loss of normal architecture, hemorrhage, and inflammatory cells infiltration detected by histopathological examination of renal, hepatic, pulmonary, and cardiac tissues in IR rats were markedly ameliorated by pre-ischemic NaHS treatment. CONCLUSION: NaHS protects against the effects of renal IR injury by acting primarily through a decrease in both pro-inflammatory cytokines and iNOS expression as well as through up-regulation of the eNOS pathway. Furthermore, H2S has a powerful anti-oxidant and anti-apoptotic effects (Tab. 2, Fig. 6, Ref. 45).

The effect of ghrelin antagonist (D-Lys3) GHRP-6 on ovariectomy-induced obesity in adult female albino rats.

OBJECTIVE: We aimed to investigate the effect of ghrelin antagonist (D-Lys3) GHRP-6 on the treatment of ovariectomy-induced obesity as compared to hormone replacement therapy with estradiol. METHODS: Twenty eight rats were divided into four groups: control sham operated (C), ovariectomized non-treated (OVX), ovariectomized+estradiol-treated (OVX+E) groups, and ovariectomized+ghrelin antagonist-treated group (OVX+GA). Rats were allowed free water and commercial standard diet ad libitum for 5 weeks after surgery. Body mass index (BMI) was determined at the beginning and the end of the experiment. Rats were sacrificed by decapitation and blood samples were collected for measurements of serum lipid profile, insulin, and glucose levels. Gastrocolic omental fat (GCOF) was removed and weighed. RESULTS: Ovariectomy was accompanied with a significantly higher body weight, food intake, BMI, GCOF, serum total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), glucose, insulin, and homeostatic model assessment - insulin resistance (HOMA-IR), with a significant decrease in high density lipoprotein-cholesterol (HDL-C) and triglycerides (TGs) in comparison with C group. Estradiol reversed the ovariectomy-induced changes except that of TGs. Administration of ghrelin antagonist was effective in treating the ovariectomy-induced obesity as evidenced by normalization of body weight, food intake, BMI, and GCOF weight, serum levels of insulin, glucose, HOMA-IR, and HDL-C. The serum levels of TC, LDL-C and TGs were improved but did not reach the control values. CONCLUSION: Although estradiol succeeded in the prevention of almost all ovariectomy-induced disturbances, it had a potential cardiovascular risk due to a marked increase in serum TGs. Ghrelin antagonist was effective in ameliorating ovariectomy-induced obesity, so it may be used as a promising treatment for postmenopausal obesity, irrespective of hormonal replacement.

The effect of induction of endogenous CO by heme-oxygenase inducer, hemin versus heme-oxygenase blocker, zinc mesoporphyrin on gastric secretion and ulceration under different conditions in adult male albino rats.

Although its role and importance is less well studied, carbon monoxide (CO) has been identified as the second gasotransmitter in the GI tract. This study was performed to investigate the effect of modifying the endogenous CO production by altering heme oxygenase (HO) activity either by induction through hemin administration or inhibition by zinc mesoporphyrin administration on gastric secretion and ulceration induced by either cold restraint stress (CRS) or indomethacin (IND) treatment in adult male albino rats. Our results revealed that hemin significantly increased HO-1 levels with an increase in carboxyhemoglobin (COHb) level while zinc mesoporphyrin significantly decreased HO-1 levels with a decrease in COHb level in all groups. Hemin pretreatment significantly attenuated the gastric mucosal lesions induced by CRS and IND administration, which was accompanied by significant reduction in free and total acidity of gastric secretion, decreased proteolytic activity and marked attenuation of lipid peroxidation inspite of decreased NO and PGE2 levels. On the other hand, Inhibition of HO-1 activity by zinc mesoporphyrin prevented most of the effects caused by hemin administration except for its similar reduction in gastric mucosal NO and PGE2 levels. On conclusion, Hemin exerts a protective effect against CRS and IND-induced gastric ulcers possibly via inducing HO-1 and increasing endogenous production of CO (Tab. 2, Fig. 4, Ref. 75).

Modelling of internal architecture of kinesin nanomotor as a machine language.

Kinesin is a protein-based natural nanomotor that transports molecular cargoes within cells by walking along microtubules. Kinesin nanomotor is considered as a bio-nanoagent which is able to sense the cell through its sensors (i.e. its heads and tail), make the decision internally and perform actions on the cell through its actuator (i.e. its motor domain). The study maps the agent-based architectural model of internal decision-making process of kinesin nanomotor to a machine language using an automata algorithm. The applied automata algorithm receives the internal agent-based architectural model of kinesin nanomotor as a deterministic finite automaton (DFA) model and generates a regular machine language. The generated regular machine language was acceptable by the architectural DFA model of the nanomotor and also in good agreement with its natural behaviour. The internal agent-based architectural model of kinesin nanomotor indicates the degree of autonomy and intelligence of the nanomotor interactions with its cell. Thus, our developed regular machine language can model the degree of autonomy and intelligence of kinesin nanomotor interactions with its cell as a language. Modelling of internal architectures of autonomous and intelligent bio-nanosystems as machine languages can lay the foundation towards the concept of bio-nanoswarms and next phases of the bio-nanorobotic systems development.

The role of surgical management in pediatric germ cell tumors (GCTs), NCI case series.

PURPOSE: To review the experience of a tertiary referral center in pediatric germ cell tumors (GCTs) in the last 8 years and to investigate the impact of surgery and site of disease on prognosis. PATIENTS AND METHODS: We retrospectively analyzed the cases of pediatric germ cell tumors at National Cancer Institute over an 8 years period. Data concerning diagnosis, surgery and medical decisions were reviewed and analyzed for all patients. A total of 34 children with (GCTS) were found, with a mean age, at presentation, of 6.7 years and a follow-up period ranging from 3-52 months. One patient with benign GCT was excluded during analysis of the results. RESULTS: Among the 34 patients, there were 14 males and 20 females with mean age of 6.7 years (range: 9 months-15 years), with male to female ratio 1:1.4. All patients were symptomatic at presentation, most commonly with abdominal swelling (18 patients; 52.9%). Anatomic distribution of GCTs according to sex organ involvement was either gonadal in 21 patients (61.8%) or extragonadal in 13 patients (38.2%). All patients had surgery either in the form of curative resection or biopsy after formal exploration and evidence of irresectability. No significant surgical morbidity or mortality were encountered in our patients. Yolk sac tumor and malignant teratoma were the commonest histologic subtypes in our series. Metastatic disease was encountered in nine out of 33 patients (27.2%). Adjuvant chemotherapy was administered in 28 out of 33 patients (84.8%), following surgery, including all patients with extragonadal disease. Our patients were followed-up to 52 months. Twenty-two patients (66.7%) had no recurrence while two patients (6.1%) died from disease. Pelvic extragonadal site was the worst site regarding resectability. Complete surgical resection showed better disease free survival, while those with irresectable disease had comparable overall survival while none could be rendered disease free with chemotherapy. CONCLUSION: The initial surgical approach to malignant GCTs at all sites should be complete resection when possible; the morbidity of extensive surgical resection should be weighed carefully against the good tumor control with chemotherapy. Surgical staging does not preclude preservation of fertility, which should always be considered in this young age. The site of primary disease plays a role in the prognosis of pediatric germ cell tumors with the extragonadal pelvic tumors being the worst regarding resectability. Good tumor response can be achieved with surgery and chemotherapy even for advanced stage and metastatic disease.

Factors affecting patient compliance with anti-tuberculosis chemotherapy using the directly observed treatment, short-course strategy (DOTS).

SETTING: Kota Kinabalu and surrounding communities in Sabah, Malaysia. OBJECTIVES: To establish factors affecting compliance of patients with anti-tuberculosis chemotherapy, their knowledge of the disease, and views on improving the DOTS strategy. DESIGN: Interviews with compliant patients attending clinics for DOTS treatment and with non-compliant patients in their homes, in August and September 2000. RESULTS: A total of 63 compliant and 23 non-compliant patients were interviewed. For non-compliant patients, reaching the treatment centre entailed greater cost (P < 0.005) and travel time (P < 0.005) compared to compliant patients. Cost of transport was the reason most frequently given for non-attendance. Non-compliant patients were more likely to have completed secondary education (P < 0.05), and to be working (P < 0.01). More non-compliant patients had family members who had had the disease (P < 0.01). There was no difference between the groups for overall tuberculosis knowledge scores; however, non-compliant patients were more likely to think that treatment could be stopped once they were symptom free (P < 0.01). Most patients (73%) felt that the DOTS system could be improved by provision of more information about tuberculosis. CONCLUSION: Compliance with DOTS in the Kota Kinabalu area is affected by travel expenses, time spent travelling to treatment centres, and having family members who have had the disease. Patients would like more information on tuberculosis.