PTH monitoring after total parathyroidectomy with forearm auto-transplantation: potential for spuriously high levels from grafted forearm.

Background: We have identified a cause of falsely elevated parathyroid hormone (PTH) levels after total parathyroidectomy with forearm auto-transplantation (TPT-ATx). Our cases highlight the need to draw PTH samples remotely, away from forearm graft sites, to ensure accurate levels.

Case Presentations: We report on four patients who were referred to our surgical team at an academic tertiary care center for what was perceived to be recurrent hyperparathyroidism 2-5 years following total parathyroidectomy with auto-transplantation.

Validation of 1-hour post-thyroidectomy parathyroid hormone level in predicting hypocalcemia.

Background: Prior work by our group suggested that a single one hour post-thyroidectomy parathyroid hormone (1 hr PTH) level could accurately stratify patients into high and low risk groups for the development of hypocalcemia. This study looks to validate the safety and efficacy of a protocol based on a 1 hr PTH threshold of 12 pg/ml.

Study Design: Retrospective analysis of consecutive cohort treated with standardized protocol.

Prediction of hypocalcemia after using 1- to 6-hour postoperative parathyroid hormone and calcium levels: an analysis of pooled individual patient data from 3 observational studies.

Background: Parathyroid hormone (PTH) levels up to 6 hours postthyroidectomy have been shown to have excellent predictive power in determining hypocalcemia. In this study, we investigate the usefulness of combining calcium and PTH to increase the predictive power.

Methods: Individual patient data were obtained from 3 studies (152 patients) that fulfilled our criteria (using PTH assay within hours postthyroidectomy to predict symptomatic hypocalcemia).

Assessing flap perfusion: optical spectroscopy versus venous doppler ultrasonography.

Objective: To use optical spectroscopy as a noninvasive method to monitor the viability of free flaps and to compare the near-infrared probe with the implantable venous Doppler ultrasound probe.

Design: Prospective, randomized series using an animal model.

Method: Optical spectroscopy was used to measure variables that correlate with tissue perfusion and oxygenation.

Impact of use of frozen section assessment of operative margins on survival in oral cancer.

Objective: This study looked at the independent impact of intraoperative frozen section assessment of the adequacy of margins of excision on disease control and survival.

Study Design: The design was a review of outcome of historical cohort of 416 surgically treated oral cancer patients at a comprehensive cancer center. Status of the margins at permanent sections, disease failure at the primary site, and survival data of 229 patients who had frozen sections were compared by univariate and multivariate analysis with 197 patients who did not have frozen sections.

Early prediction of hypocalcemia after thyroidectomy using parathyroid hormone: an analysis of pooled individual patient data from nine observational studies.

Background: Monitoring for hypocalcemia after thyroidectomy, using only symptoms and serum calcium levels, can delay the discharge of patients who will remain normocalcemic and can delay the treatment of hypocalcemic patients.

Study Design: We conducted a systematic search for articles describing use of parathyroid hormone (PTH) assay, checked within hours of completing thyroidectomy, to predict postoperative symptomatic hypocalcemia. Studies were excluded if all patients were treated with postoperative calcium, or if early PTH values were used to alter management of the patient.

Structure-activity studies with cytotoxic anthrapyrazoles.

Anthrapyrazoles have been investigated as cancer chemotherapeutic agents. The mechanism of action of these compounds is thought to involve inhibition of DNA topoisomerase II. A structure-activity study was carried out to determine the in vitro cytotoxic activity of nine novel anthrapyrazoles against human breast carcinoma, head and neck squamous cell carcinoma and leukemia cells, and against Chinese hamster ovary cells.

Role of NQO1 polymorphisms as risk factors for squamous cell carcinoma of the head and neck.

A case: control study was carried out to determine if inactivating polymorphisms of the NQO1 gene at bases 609 and 465 are associated with altered risk of developing squamous cell carcinoma of the head and neck (SCCHN). Genotyping was carried out by PCR RFLP analysis on whole blood samples. The frequency of the inactive 609T and active 609C forms, and the inactive 465T and active 465C forms, of NQO1 were compared in patient and control groups by a logistic regression analysis and odds ratios (ORs) were calculated.

c-Myc induces chromosomal rearrangements through telomere and chromosome remodeling in the interphase nucleus.

In previous work, we showed that telomeres of normal cells are organized within the 3D space of the interphase nucleus in a nonoverlapping and cell cycle-dependent manner. This order is distorted in tumor cell nuclei where telomeres are found in close association forming aggregates of various numbers and sizes. Here we show that c-Myc overexpression induces telomeric aggregations in the interphase nucleus.

The three-dimensional organization of telomeres in the nucleus of mammalian cells.

Background: The observation of multiple genetic markers in situ by optical microscopy and their relevance to the study of three-dimensional (3D) chromosomal organization in the nucleus have been greatly developed in the last decade. These methods are important in cancer research because cancer is characterized by multiple alterations that affect the modulation of gene expression and the stability of the genome. It is, therefore, essential to analyze the 3D genome organization of the interphase nucleus in both normal and cancer cells.

Parathyroid hormone: an early predictor of postthyroidectomy hypocalcemia.

Objective: To determine whether there is a correlation between the level of parathyroid hormone (PTH) soon after thyroidectomy and the development of hypocalcemia.

Study Design: Prospective series of 40 consecutive patients undergoing total thyroidectomy or completion thyroidectomy between January 2001 and October 2002.

Method: Ionized calcium was measured before surgery and at 1, 6, 18, 30, and 42 hours after surgery.

Paranasal sinus teratocarcinosarcoma with intradural extension.

Teratocarcinosarcoma, although a rare neoplastic entity, should be considered as a differential diagnosis in any middle-aged adult presenting with a history of intermittent unilateral epistaxis and nasal obstruction. Tissue biopsy may fail to reveal a full spectrum of histologic heterogeneity in these tumours, and definitive diagnosis is usually made with tumour resection. Aggressive treatment including surgery followed by adjuvant radiation therapy is advocated and confers a better rate of survival than radiotherapy alone.