PET-CT in recurrent head neck cancers: a study to evaluate impact on patient management.

BACKGROUND AND OBJECTIVES: PET-CT has shown promise in the management of head neck cancers. However, there have been only few studies evaluating its impact on management of patients with recurrent cancers in the presence of available clinicoradiologic methods of assessment. We conducted this study to assess the same in patients with suspected recurrent head and neck cancer. METHODS: Case histories were presented to two oncologists, who were blinded to PET-CT reports. Treatment plans were made by these oncologists based on clinical findings and other conventional imaging. These plans were then compared to the actual treatment received by patients after PET-CT. Any change was recorded as "change in management." RESULTS: Forty-nine patients with suspected recurrent head and neck cancer were evaluated in the study. Overall, there was a 38.7% change in management because of the addition of PET-CT to conventional methods of assessment. Eight patients (16.3%) had a major change in therapy while in 11 patients (22.4%), diagnostic procedures like endoscopies, biopsies and examination under anesthesia were avoided. CONCLUSION: In our study, PET-CT had a significant impact on the management of patients with suspected recurrent head neck cancer.

In vitro chemosensitivity profile of oral squamous cell cancer and its correlation with clinical response to chemotherapy.

CONTEXT: Oral cancers represent a disparate group of tumors with diverse clinical behavior and chemosensitivity profile. Currently, it is difficult to predict whether a tumor will respond to chemotherapy and which drug(s) will achieve the maximum clinical response. AIMS: To study in vitro chemosensitivity profile of oral cancers and to correlate the in vitro chemosensitivity of oral cancer to clinical response to chemotherapy. SETTINGS AND DESIGN: Prospective study in a tertiary cancer care center. METHODS AND MATERIAL: We prospectively studied the chemosensitivity profile of 57 untreated, advanced, unresectable oral cancers to cisplatin, methotrexate, 5-fluorouracil and their combinations by using histoculture drug response assay (HDRA) and correlated them to the clinical response to chemotherapy. STATISTICAL ANALYSIS USED: Chi Square test. RESULTS: Biopsy samples were successfully histocultured in 52/57 (91%) cases. Of these 52 evaluable patients, 47 had primary gingivo-buccal cancers and five had tongue / floor of mouth cancers. Based on the assay, 27 (52%) tumors were sensitive to cisplatin, 27 (52%) to methotrexate, 24 (46%) to 5-fluorouracil, 38 (73%) to combination of cisplatin and methotrexate and 36 (69%) to combination of cisplatin and 5-fluorouracil. Of these, 31 patients with good performance status received two cycles of chemotherapy using one or more of these test drugs. There was a significant correlation (p=0.03) between the in vitro chemosensitivity and the clinical response. Negative predictive value of the test was 80%, positive predictive value-69%, sensitivity-79% and specificity -71%. The overall accuracy of the assay was 74%. CONCLUSIONS: We found HDRA to be a fairly good predictor of chemo-response of oral cancer.

Transition-metal-mediated reactions in combinatorial synthesis.

Transition-metal-mediated reactions have played an important role in expanding the scope of combinatorial chemistry from synthesis of peptidic libraries to synthesis of nonoligomeric, small-molecule libraries. Versatile reactions such as heteroannulations, olefin metathesis and dipolar cycloadditions are used for preparation of libraries of historical, as well as novel, pharmacophores. Transition-metal-mediated reactions have also been used strategically to provide traceless linkers' in solid-phase synthesis.

Simultaneous reconstruction of large skin and mucosal defect following head and neck surgery with a single skin paddle pectoralis major myocutaneous flap.

The pectoralis major myocutaneous (PMMC) flap is commonly used for head and neck reconstruction especially in impoverished nations. PMMC is a sturdy pedicled flap with relatively fewer complications, the learning curve is short and no specialized training in microvascular surgery is needed in order to use this flap. In a defect that requires a large skin and mucosal lining the authors routinely use either a bi-paddle PMMC or a combination of PMMC (for the mucosal lining) and a delto-pectoral flap (for the skin defect). It is indisputable that free tissue transfer is a better way of reconstruction for the majority of most such defects. Unfortunately, not all patients can be offered this form of reconstruction due to the cost, time, expertise and infrastructural constraints in high volume centres such as ours. Bi-paddling of PMMC is hazardous in obese males and most female patients. In such patients the skin defect is reconstructed usually by the delto-pectoral (DP) flap but this, for obvious reasons, is less welcomed by the patients. The authors suggest a technique wherein mucosal lining is created by the myofascial lining (inner surface) of the flap and the skin defect is reconstructed by the skin paddle of the single paddle PMMC. It should be considered wherever a DP flap is unacceptable, or bi-paddling or free tissue transfer is not possible.

Quality of life of head and neck cancer patient: validation of the European organization for research and treatment of cancer QLQ-C30 and European organization for research and treatment of cancer QLQ-H&N 35 in Indian patients.

AIMS: To present the first cross-culture validation of the European organization for research and treatment of cancer (EORTC) quality of life questionnaires, the EORTC-QLQ-C30, and the QLQ-H&N 35 in India. SETTINGS AND DESIGN: These questionnaires were translated into two vernacular languages and pilot test was done on 15 patients. Two hundred head and neck cancer patients completed the QLQ-C30 and the QLQ-H&N 35 at two time points during their treatment. Psychometric evaluation of the structure, reliability, and validity of the questionnaire was undertaken. RESULTS: The data supports the reliability of the scales. Validity was tested by item-scale, scale--scale correlation and by performing known group comparisons. The results demonstrated that the items correlated with their respective scale and no significant correlation was found between scales. The questionnaire was responsive to change over a period of time. SUMMARY: This data suggests that the EORTC QLO-C30 and the QLQ-H&N 35 are reliable and valid questionnaires when applied to a sample of head and neck cancer patients in India.

Mapping the binding site of tissue kallikrein: preparation and testing of all possible substrate analog inhibitors homologous with the sequence of kininogen between Ser386 and Gln392.

Programs aimed at converting peptide inhibitors of proteolytic enzymes into more traditional drug structures require an understanding of the role played by the individual amino acid residues in the inhibitor. To this end, all possible substrate analogues occurring within the sequence Ser386-Pro-Phe-Arg-Ser-Val-Gln392 from bovine kininogen were synthesized and tested as inhibitors of tissue kallikrein (EC 3.4.21.35, beta-PPK). Of the 21 sequences which can be formed from the heptapeptide, 11 have inhibitory constants which could be measured in the chromogenic assay employed in these studies. No dipeptide and only one tripeptide, Ac-Phe-Arg-Ser-NH2 (Ki = 718 microM), measurably inhibits the enzyme. All longer peptides inhibit beta-PPK. The heptapeptide Ac-Ser-Pro-Phe-Arg-Ser-Val-Gln-NH2 is the most effective inhibitor in this series (Ki = 101 microM). Each amino acid residue in the sequence appears to alter binding in a relatively independent manner. The N-terminal seryl residue (P4) and the prolyl residue (P3) slightly improve the Ki of the various inhibitors. The phenylalanyl residue at P2 appears to have a more pronounced effect on Ki. The arginyl residue at P1 and the seryl residue at P1' appear to be the most important residues in the inhibitory sequence. They contribute approximately one-third and one-fourth of the binding energy to the interaction between the substrate analogues and beta-PPK, respectively. The valyl residue at P2', and the C-terminal glutaminyl residue improve Ki of each of the peptides tested. Almost 80% of the binding energy of the substrate analogue inhibitors comes from the core sequence Phe-Arg-Ser which occurs between P2 and P1'. Molecular models developed from the Chen-Bode coordinates of the aprotinin-beta-PPK complex have been used to interpret the results of these studies.

Bovine lymphocyte antigen-A11--specific peptide motif as a means to identify cytotoxic T-lymphocyte epitopes of bovine herpesvirus 1.

Major histocompatibility complex (MHC) class I molecules present 8- to 10-mer viral peptides to antiviral cytotoxic T lymphocytes (CTLs). Identification of the allele-specific peptide motifs (ASPMs) of class I molecules enables the prediction of potential CTL epitopes of a virus from its protein sequences. Based on the bovine herpesvirus 1 (BHV-1) protein sequences that conform to the BoLA-A11 ASPM that we identified previously, potential CTL epitopes of BHV-1 were synthesized for use in cytotoxicity assays with CTLs from BHV-1-immunized calves. A peptide binding assay used to select the peptides that are most likely to be CTL epitopes categorized the peptides into groups of high, intermediate, and low binding capacity. Synthetic peptides stimulated lymphocytes from BHV-1-immunized calves to secrete interferon-gamma. Groups of peptides from the major glycoproteins of BHV-1 restimulated CTLs in vitro and sensitized targets for lysis by means of restimulated bulk CTLs.

Recent advances in the solid phase synthesis of drug-like heterocyclic small molecules.

Phage display is a biological system which facilitates the cloning and rapid selection of peptides from large combinatorial libraries. In compa-rison to the chemical combinatorial approach, the advantages of phage display lie in its simplicity and replicability. While phage display has many diverse applications, this review will focus on the use of phage peptide libraries to discover epitopes recognised by monoclonal antibodies. As monoclonal antibodies are useful tools for the detection of proteins and for the investigation of molecular interactions, the identification of their epitopes will serve to elucidate the structure and function of proteins, as well as aid in the discovery of new drugs and the development of vaccines.

A novel cleavage protocol for use with Rf-encoded split pool synthesis technology: product cleavage and collection in standard 96 well format.

A novel protocol which employs commercially available, standard tools and hardware has been developed. This protocol allows for cleavage and collection of IRORI Microkan products in 96 well plate format. Typically, 640 compounds can be cleaved in a 4 hour time period using approximately 3 square feet of space. This protocol has been used successfully for the liberation of thousands of individual compounds, in single compound per well format from the solid phase. Additionally, this protocol is the first example of making IRORI Microkan technology directly compatible with standard 96 position deep well blocks.

Marginal mandibulectomy for lateral sulcus tumours.

OBJECTIVE: To report a retrospective series of marginal mandibulectomy for cancers of oral cavity, with special reference to squamous cancers of gingival buccal complex. METHODS: Retrospective record review of 107 patients who underwent marginal mandibulectomy between 1994 and 2001. RESULTS: Eighty-three marginal mandibulectomies were done for gingivo-buccal complex cancers. Local failure rate was 16%. The 2-year and 5-year disease free survival rates were 69 and 60%, respectively. The local recurrence free survival at the end of 2 and 5 years were 79 and 70%, respectively. CONCLUSION: In carefully selected patients, marginal mandibulectomy is an oncologically safe procedure to achieve good local control.

Core needle biopsy for bone tumours.

INTRODUCTION: Percutaneous core biopsy of bone lesions provides early and definitive diagnosis and guides decisions on management. It is an inexpensive examination technique and has negligible complication rates. METHODS: We performed a prospective study of 136 patients who underwent core biopsies for bone lesions over an 18-month period. A Jamshidi (J) needle was used to obtain a core of tissue and specimens were sent for histopathological examination. Biopsy results were analysed for adequacy, ability to yield diagnostic information and for accuracy of diagnosis. RESULTS: The mean age of patients was 27.5 years with a range of 3-72 years. There were 84 males and 52 females in the study. Histopathological diagnosis was obtained in 121 (89%) patients. The specimen was non-diagnostic in 15 patients. Fourteen patients required two attempts and two patients required three attempts at biopsy. Sixty-two of 64 patients (96.9%) who had a confirmed final diagnosis had an accurate J-needle histopathological diagnosis. None of the patients had any major complications. DISCUSSION: Core needle biopsy is an important tool in the evaluation of bone lesions. It is a safe, reliable and accurate procedure and yields diagnostic information in a high proportion of patients. It has several advantages over an open bone biopsy.

Upfront submandibular salivary gland transfer in pharyngeal cancers.

Head and neck irradiation results in salivary dysfunction and subsequent xerostomia. Twenty two patients with squamous cancer of oropharynx or hypopharynx underwent contralateral submandibular salivary gland transfer (SMSGT) to submental triangle to shield it from subsequent radiotherapy. Resting salivary outputs of transferred and untransferred gland (control) were measured before and after SMSGT and following radiotherapy, by cannulating individual submandibular duct. They were compared by paired samples t-test. Following radiation therapy transferred gland retained 73% and untransferred gland (control) retained 27% of baseline salivary output. This significant difference in post-radiation salivary outputs suggests preservation of function of transferred salivary gland.

Metastatic adenocarcinoma in testis presenting as a testicular mass--a case report and review of literature.

Testicular metastasis presenting as a testicular mass is an extremely rare condition. There are only nine previously reported cases where testicular mass was the first clinical manifestation of underlying malignancy. Here we report a case of metastatic mucin secreting adenocarcinoma in testis presenting as a testicular mass with unknown primary. We have given a brief review of literature about the spread of tumor to testes.

Effect of shilajit on the heart of Daphnia: A preliminary study.

Shilajit is a mineral-rich complex organic compound used in the traditional system of Ayurvedic medicine for treating hypertension and improving the cardiac function with many herbomineral preparations. However, very little experimental evidence is available about its effect on the cardiac function. We used Daphnia as a model organism for observing the effect of shilajit on its heart due to its myogenic properties and its response to number of cardioactive drugs that are known to affect human heart function. Genome of Daphnia shows the strongest homology with the human genome. These characteristics of Daphnia make it an ideal organism for biomedical research. Our results suggest that this complex organic compound lowers the heart beats as its concentration increases from 1.0 to 100 ppm. The beats come to near normal condition at 1000 ppm. Above 1000 ppm, the beats are very fast and impossible to count. These results indicate a negative chronotropic effect on the Daphnia heart at low concentrations and a positive chronotropic effect to arrhythmia and finally failure at increasing higher concentrations of shilajit.

Prosthetic voice rehabilitation after total laryngectomy.

Loss of voice is a major concern after total laryngectomy. Tracheo-esophageal prosthesis was described in 1980 by Blom and Singer as a method of postlaryngectomy voice rehabilitation. Since then it has seen many phases of developments. Now it has evolved into highly effective method with success rates more than 90% and better quality of voice than other modalities. It also gives good quality of life and voice related quality of life. Though it is associated with some complications, they are easy to manage. All these have made tracheo-esophageal prosthesis the 'Gold Standard' of post-laryngectomy voice rehabilitation.