Surface topography of zirconia implants does not alter action potentials of isolated rat sciatic nerves

The purpose of this study was to explore the effects of airborne-particle abrasion and selective infiltration etching of a yttrium-partially stabilized tetragonal zirconia polycrystal (Y-TZP) implant surfaces on nerve conduction. Particle-abraded Y-TZP (P/Y-TZP), selective infiltration etched Y-TZP (SIE/Y-TZP), and commercially pure titanium (CP-Ti) were used in the study (n = 5).The compound action potentials of the right and left sciatic nerves of eight sacrificed rats were quantified at the in vitro level. The implants were brought into intimate contact with the nerves and the time required for initiation of compound action potentials (TcAP), depolarization (Dp), repolarization (Rp), and amplitude of evoked compound action potentials (cAPs) were recorded before and after contact with the implants. The difference in cAPs between the basal response and after contact with CP-Ti implant was significant (p < 0.05). Time-dependent changes in cAPs of P/Y-TZP and SIE/Y-TZP groups and their basal nerve responses were similar (p > 0.05). Within- and between-subject comparisons revealed that TcAP, Dp, and Rp values for all groups were similar (p > 0.05). Particle-abraded and selective infiltration-etched zirconia implant surfaces do not alter nerve conduction beyond physiologic limits.     

A very rare adult case with neuroblastoma

We report a 53-year-old male patient who underwent paravertebral mass excision at the D10-11-12 vertebral levels in 2007. The histopathological evaluation of the mass showed the presence of neuroblastoma. The patient was diagnosed with stage IV neuroblastoma. He received 6 courses of chemotherapy and exhibited a stable course until March 2010. When he was reevaluated in March 2010, progression in the metastatic lesion as well as local recurrence was detected. The patient, who was restarted on chemotherapy, developed progressive weakness and loss of sensation of the lower extremity. The neurosurgical investigation revealed an irreversible loss in motor functions. The patient is currently on symptomatic treatment.     

A malignant mass in the breast is not always breast cancer

A 37-year-old woman presented to the Internal Medicine Clinic with complaints of abdominal pain and constipation which had begun 3 months earlier. A colonoscopy was performed, and wall thickening of the sigmoid colon was detected. A biopsy of the sigmoid colon revealed a poorly differentiated, mucin-producing adenocarcinoma with a signet-ring pattern. No distant metastasis was detected. The patient was treated with chemotherapy consisting of 5-fluorouracil, leucovorin, and oxaliplatin. One and a half years later, a painless mass, which was not fixed to the skin, measuring 1 cm in diameter, was found in the lower outer quadrant of the left breast. A core biopsy of the mass was performed, and a histopathological report confirmed metastasis to the breast from mucinous adenocarcinoma of an intestinal primary.     

Does adenosine A1 receptor stimulation causes QRS prolongation by blocking beta adrenergic receptors in amitriptyline poisoning?

Aims

To investigate the role of beta receptor blockade via adenosine A₁ receptor stimulation on amitriptyline-induced QRS prolongation.

Methods

Isolated rat hearts were randomized into three groups (n = 8 for each group). After pretreatment with 5% dextrose (control) or DPCPX (8-cyclopentyl-1,3-dipropylxanthine), or propranolol + DPCPX, amitriptyline infusion was given to all groups. Intact beta adrenergic receptor response was verified with a bolus dose of isoproteranol (3 × 10⁻⁵ M).

Results

Amitriptyline (5.5 × 10⁻⁵ M) infusion following pretreatment with 5% dextrose or 10⁻⁴ M DPCPX prolonged QRS by 40–110% and 30–75%, respectively. After the beta receptor blockade with 10⁻² M propranolol bolus, amitriptyline infusion following pretreatment with DPCPX prolonged QRS by 40–130%. Amitriptyline infusion following pretreatment with DPCPX (10⁻⁴ M) shortened the QRS at 40, 50 and 60  min significantly when compared to propranolol + DPCPX group (168.8 ± 4.9%, p < 0.05; 170.8 ± 6.9%, p < 0.01; 174.0 ± 6.9%, p < 0.01, respectively). Amitriptyline infusion following pretreatment with 5% dextrose prolonged QRS duration significantly at 50th minutes (209.5 ± 6.1%, p < 0.05) compared to DPCPX pretreatment group.

Conclusion

DPCPX pretreatment shortened amitriptyline-induced QRS prolongation. Beta adrenergic receptor blockade enhanced QRS prolongation shortened by DPCPX pretreatment. Adenosine A₁ receptor stimulation related to beta adrenergic receptor blockade may play a role in amitriptyline-induced QRS prolongation in isolated rat hearts.     

Amphipathic DNA polymers exhibit antiherpetic activity in vitro and in vivo

Phosphorothioated oligonucleotides have a sequence-independent antiviral activity as amphipathic polymers (APs). The activity of these agents against herpesvirus infections in vitro and in vivo was investigated. The previously established sequence-independent, phosphorothioation-dependent antiviral activity of APs was confirmed in vitro by showing that a variety of equivalently sized homo- and heteropolymeric AP sequences were similarly active against herpes simplex virus type 1 (HSV-1) infection in vitro compared to the 40mer degenerate parent compound (REP 9), while the absence of phosphorothioation resulted in the loss of antiviral activity. In addition, REP 9 demonstrated in vitro activity against a broad spectrum of other herpesviruses: HSV-2 (50% effective concentration [EC(50)], 0.02 to 0.06 microM), human cytomegalovirus (EC(50), 0.02 to 0.13 microM), varicella zoster virus (EC(50), <0.02 microM), Epstein-Barr virus (EC(50), 14.7 microM) and human herpesvirus types 6A/B (EC(50), 2.9 to 10.2 microM). The murine microbicide model of genital HSV-2 was then used to evaluate in vivo activity. REP 9 (275 mg/ml) protected 75% of animals from disease and infection when provided 5 or 30 min prior to vaginal challenge. When an acid-stable analog (REP 9C) was used, 75% of mice were protected when treated with 240 mg/ml 5 min prior to infection (P < 0.001), while a lower dose (100 mg/ml) protected 100% of the mice (P < 0.001). The acid stable REP 9C formulation also provided protection at 30 min (83%, P < 0.001) and 60 min (50%, P = 0.07) against disease. These observations suggest that APs may have microbicidal activity and potential as broad-spectrum antiherpetic agents and represent a novel class of agents that should be studied further.     

Calcifying aponeurotic fibroma: a case report

Calcified aponeurotic fibroma is a rare benign fibrous tumor with well-characterized histopathologic features. It is usually seen in distal extremities of children and youngsters. A 23-year-old male patient underwent surgical excision of a free, painless soft tissue mass that developed in the palmar aspect of the left hand. Histopathologic examination showed fibroblastic proliferation areas and dense collagenous stroma surrounding calcifications and chondroid metaplasia. The diagnosis was made as calcified aponeurotic fibroma. No recurrences were detected within a year follow-up.     

Challenges of radiological assessment in an infant with giant calcified hepatoblastoma

Hepatoblastoma is a rare neoplasm of all pediatric cancers. The goal of treatment is to remove the tumor completely because cure without complete resection is extremely unusual. Accurate assessment of tumor resectability following preoperative chemotherapy is of crucial importance. It is sometimes difficult, especially when the tumor is as large and calcified as in the described case. Detailed radiological imaging such as computed tomography angiography or magnetic resonance angiography is the key for selecting the proper treatment method in hepatoblastoma during the preoperative period. In this article, we report a successfully treated giant calcified hepatoblastoma despite radiological assessment complexity.     

Glucose phosphate isomerase (GPI) Tadikonda: Characterization of a novel Pro340Ser mutation

After a thirty-year lag, we serendipitously reestablished contact with a patient with glucose phosphate isomerase deficiency and hydrops fetalis first reported in 1987. We now provide a clinical update and provide results of mutation analysis in this patient, from Southern India. The patient now an adult female of 36 years of age has moderate anemia but requires no transfusions except with some intercurrent illnesses. Exome sequencing studies showed a homozygous c.1018C>T (Pro340Ser) mutation in exon 12 of the glucose phosphate isomerase gene and later confirmed by direct sequencing. This mutation has not been previously described. To our knowledge, this is also the first known homozygous mutation in the hydrophobic core of the protein and is a highly deleterious mutation by in silico analysis and by clinical history in the family. Flow cytometry studies of band 3 content with eosin maleimide showed a unique tail of red cells on histograms, reflecting the dense red cells (presumably ATP depleted) seen on blood smears; similar findings were seen in patients with pyruvate kinase and phosphoglycerate kinase deficiency.