Release and distribution of [3H]norepinephrine in nonpigmented and pigmented rabbit iris.

Unequal accumulation of drugs in pigmented and nonpigmented iris has been known for some time. However, at low concentrations of the sympathetic neurotransmitter norepinephrine, the accumulation is equal in both types of irides. The spontaneous and potassium-induced release of 3H was studied in isolated rabbit irides labeled with 0.1 micron [3H]norepinephrine ([3H]NE). The spontaneous outflow and the tissue 3H content were similar in both types of irides, but the potassium-induced release was significantly higher in nonpigmented iris. When irides were labeled with [3H]NE in the presence of 1 micron desmethylimipramine, the potassium-induced release was still significantly higher in nonpigmented than in pigmented iris, although the tissue 3H content was higher in the latter. Subcellular distribution of [3H]NE in both types of irides is presented. The data indicate that [3H]NE is distributed unequally in both types of irides in spite of equal tissue accumulation. The binding of NE by the pigment cell suggests an additional site of loss, or site of uptake, of the transmitter in melanin-containing tissues. The physiological significance of such an unequal release in relation to the evolutionary adaptation of the eye to light is discussed.     

Carpometacarpal Joint Fracture Dislocation of Second to Fifth Finger

Background

Carpometacarpal joint fracture dislocation of the second to fifth finger is a rare hand injury associated with high energy trauma. Due to severe swelling and overlapping of bones on the radiograph of wrist-hand, dislocations are missed. We reported a series of six patients with rare carpometacarpal joint fracture dislocation treated with open reduction.

Methods

We retrospectively studied six cases of carpometacarpal joint fracture dislocation. All patients were treated with open reduction and internal fixation with Kirschner wire. Functional assessment was done with Quick Disabilities of the Arm, Shoulder and Hand score (Quick DASH score) at regular intervals.

Results

Average Quick DASH score was improved from 75.76 to 1.9 from 6 weeks to 18 months of duration. Of the six patients, three patients had a Quick DASH score of 0 at the end of 18 months.

Conclusions

Careful hand examination and radiographic assessment is necessary to avoid missed diagnosis of carpometacarpal joint fracture dislocation. Early open reduction and internal fixation lead to excellent recovery of hand function.     

Percutaneous coronary interventions in diabetic patients: is complete revascularization important?

BACKGROUND: The long-term prognosis of diabetic patients with multivessel coronary artery disease (CAD) treated by surgical or percutaneous coronary revascularization is significantly worse as compared to non-diabetics. Lower rates of complete revascularization may be one factor that influences the poor long-term outcome in the diabetic population. Our study assessed the impact of complete revascularization on the long-term prognosis in diabetic patients with CAD treated by percutaneous coronary intervention (PCI). The study included 658 consecutive diabetic patients (mean age, 60.9+/-10.1 years) who underwent PCI. Multivessel disease was present in 352 patients (53.5%). Revascularization was complete in 94 (26.7%) and incomplete in 258 (73.3%) patients with multivessel disease. Reasons for incomplete revascularization included angioplasty of only the culprit lesion (43.4%); small vessel size (22.8%); moderate lesion, defined as diameter stenosis 50-69% (18.6%); chronic total occlusion of the non-intervened vessel (6.6%); and others (8.5%). Overall survival rate at 5 years was 87.4%. Patients who underwent complete revascularization had a 94.5% survival rate, compared to 83.0% for those with incomplete revascularization (p<0.001). Similarly, the rates of myocardial infarction-free survival were significantly higher in patients with complete versus incomplete revascularization (92.9% versus 79.9%, respectively). Incomplete revascularization was the most powerful independent predictor of mortality at follow-up (relative risk 95% confidence interval, 1.54-7.69; p=0.003). Our data suggest that complete myocardial revascularization may improve the long-term prognosis after PCI of diabetic patients with multivessel CAD.     

Ophthalmic Complication Following Posterior Superior Alveolar Nerve Block for Tooth Extraction! A Rare Occurrence

One of the most commonly asked question by a patient who comes for extraction especially in the rural areas is whether the procedure will cause problems to the eye!! In reality however, ophthalmic complications following routine maxillary molar extractions are practically unheard of. When they occur they can be extremely unnerving not just to the patient but also to the surgeon. Patients generally panic which makes it tougher for the clinician to assess the situation. We present a case of a 26 year old female patient developing ophthalmic complication following local anesthesia administration during extraction of upper left maxillary third molar. In this article, ophthalmic complications arising from posterior superior alveolar nerve block are discussed and management guidelines are highlighted.     

Mechanical and Tribological Behavior of Mechanically Alloyed Ni-TiC Composites Processed via Spark Plasma Sintering

Titanium carbide (TiC) reinforced nickel (Ni) matrix composites were processed via mechanical alloying (MA) followed by spark plasma sintering (SPS) process. Mechanical alloying has gained special attention as a powerful non-equilibrium process for fabricating amorphous and nanocrystalline materials, whereas spark plasma sintering (SPS) is a unique technique for processing dense and near net shape bulk alloys with homogenous microstructure. TiC reinforcement varied from 5 to 50 wt.% into nickel matrix to investigate its effect on the microstructure and mechanical behavior of Ni-TiC composites. All Ni-TiC composites powder was mechanically alloyed using planetary high energy ball mill with 400 rpm and ball to powder ratio (BPR) 15:1 for 24 h. Bulk Ni-TiC composites were then sintered via SPS process at 50 MPa pressure and 900–1200 °C temperature. All Ni-TiC composites exhibited higher microhardness and compressive strength than pure nickel due to the presence of homogeneously distributed TiC particles within the nickel matrix, matrix grain refinement, and excellent interfacial bonding between nickel and TiC reinforcement. There is an increase in Ni-TiC composites microhardness with an increase in TiC reinforcement from 5 to 50 wt.%, and it reaches the maximum value of 900 HV for Ni-50TiC composites.