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Biomedical subjects

G Snow

Publications and source records attributed to G Snow.

10 recordsLinked to original sources

Long-term results of organ preservation in chondrosarcoma of the cricoid.

Chondrosarcoma of the larynx is rare. The posterolateral lamina of the cricoid cartilage is the site most commonly involved. Although the symptomology, radiological and histopathological diagnostic features are well known, the condition continues to be diagnosed late and recurrences after excision are common. In general, radical surgical excision can result in long-term remission, although prognosis is related to the histopathological grade of the tumor. While a conservative surgical approach in low-grade tumors is justified, unexplained hoarseness, unilateral vocal cord paralysis and dyspnea requires CT scan examination.

Aged↗

Carcinoma of the ethmoid: results of treatment with conventional surgery and post-operative radiotherapy.

AIMS: A retrospective study was carried out of 50 patients with carcinoma of the ethmoid, treated over a period of 20 years. METHODS: The treatment used was surgery, followed by post-operative external beam radiotherapy and when possible supplemented by brachytherapy. RESULTS: Although the nature of surgery in the majority of cases was conventional, the 63% 5-year overall survival, except in adenocarcinomas, was slightly better than that achieved by more aggressive surgery. There was no mortality and morbidity was minimal. CONCLUSIONS: Conventional surgery in combination with radiotherapy and brachytherapy gives satisfactory and comparable results.

Adenocarcinoma↗

Effect of combination antiretroviral therapy upon rectal mucosal HIV RNA burden and mononuclear cell apoptosis.

BACKGROUND: Pathogen-negative diarrhea is common in HIV infection and has been associated with clinical symptoms, histopathology, HIV expression, CD4+ lymphocyte depletion, cytokine mRNA expression, and apoptosis of lamina propria mononuclear cells. OBJECTIVES AND METHODS: To examine the short-term (7-day) effects of treatment with combination antiretroviral therapies upon gastrointestinal symptoms and rectal mucosa in 15 HIV-infected subjects. RESULTS: Treatment was associated with significant decreases in the perception of abdominal bloating and cramps. Similar declines in RNA burden and rises in CD4+ lymphocyte counts were found in blood and mucosa. Treatment was also associated with a fall in the number of lamina propria mononuclear cells undergoing apoptosis by in situ labeling, a change that correlated with the change in mucosal viral burden. CONCLUSIONS: Peripheral blood and mucosal compartments are equally responsive to effective antiretroviral therapies. The detection of significant changes within 7 days of starting antiviral therapy implies that intestinal dysfunction may be a direct result of local HIV infection.

Anti-HIV Agents↗

Studies of the anatomy and pathology of the orbit in carcinoma of the maxillary sinus and their impact on preservation of the eye in maxillectomy.

BACKGROUND: The periorbita has been traditionally regarded as the decisive layer whose involvement in carcinoma of maxillary sinus indicates orbital exenteration. Anatomic texts depict that the orbital fat rests on the periorbita. Our experience at surgical dissections has been different. METHODS: Twenty-five patients underwent total maxillectomy for advanced (T3-T4) carcinoma of the maxillary sinus with postoperative radiotherapy during a 15-year period between 1981 and 1995. In 11 patients, despite radiologic evidence of orbital invasion, and in 5 patients with infiltration of the periorbita, the eye could be preserved without evidence of recurrence. In 6 patients who in addition underwent orbital exenteration, histopathologic evidence of tumor invasion of the orbit was present in only one surgical specimen. RESULTS: Clinicoanatomic studies have clearly shown the presence of a thin, distinct fascial layer which surrounds the periocular fat and separates it from the periorbita. Neither clinical examination nor imaging could predict orbital invasion with absolute accuracy. Histopathologic examination of the surgical specimens shows that tumor infiltration of the eye is rare. CONCLUSION: Periocular fat is surrounded by a thin fascial layer and is not in direct contact with the periorbita. Intraoperative decision making with respect to preservation of the eye is sometimes essential.

Combined Modality Therapy↗

Selective depletion of rectal lamina propria rather than lymphoid aggregate CD4 lymphocytes in HIV infection.

The goal of this study was to examine the changes in lymphocyte populations in rectal mucosa during HIV infection and to study their relationship to mucosal immunity and to systemic depletion of CD4 lymphocytes. Rectal biopsies from 58 HIV-infected subjects and eight controls were studied. Frozen rectal tissue sections were stained with antibodies to CD4, CD3, CD8, and markers for macrophages. HIV-infected subjects were divided into early stage (no opportunistic infections) and AIDS groups. There was profound depletion of rectal lamina propria CD4 lymphocytes (16% and 6% of normal content in early and AIDS groups, respectively). However, lymphoid aggregate CD4 lymphocytes were far less severely depleted (69% and 40% of normal content, respectively). The extent of lymphoid aggregate CD4 lymphocyte depletion generally parallelled the CD4 lymphocyte depletion in the blood. CD8 lymphocyte content in both the lamina propria and lymphoid aggregates usually were increased, particularly in early-stage patients. Macrophage contents were usually normal in the HIV-infected groups. We conclude that rectal lamina propria and lymphoid aggregates are distinct compartments differing markedly in their CD4 lymphocyte content during HIV infection. In light of this and an increased number of apoptotic cells which were noted in rectal lamina propria in HIV-infected subjects, we hypothesize that intestinal lamina propria could be a site of rapid CD4 lymphocyte destruction during HIV infection.

Acquired Immunodeficiency Syndrome↗

The use of general primers in the polymerase chain reaction permits the detection of a broad spectrum of human papillomavirus genotypes.

A novel polymerase chain reaction (PCR) method was developed that permits the detection of 11 different human papillomavirus (HPV) genotypes using two general primer sets. By computer-assisted sequence analysis, two pairs of general primers were selected from the conserved L1 open reading frame and tested in the PCR on a set of cloned HPV genotypes. Experimental analysis showed that up to three mismatches between primers and target DNA did not influence the efficiency of the assay. The use of these primers in the PCR enabled the detection of HPV genotypes HPV-1a, -6, -8, -11, -13, -16, -18, -30, -31, -32 and -33, and was also successfully applied to well characterized cervical carcinoma cell lines and clinical samples. For the HPV types tested sub-picogram amounts of cloned DNA could be detected after general primer-mediated PCR and subsequent hybridization. The specificity of the amplification products was confirmed by blot hybridization procedures and RsaI restriction enzyme digestion. The results indicate that this PCR method can be a powerful tool for identifying novel HPV genotypes in dysplasias and squamous cell carcinomas suspected of having an HPV aetiology.

Base Sequence↗

The value of postoperative radiotherapy as an adjuvant to radical neck dissection.

In this study the results of combined radiotherapy and surgery are compared with the results of surgery alone in patients with neck node metastases from squamous cell carcinomas of the head and neck region. Postoperative radiotherapy decreases the recurrence rate in the neck, especially in cases with histologically established extranodal spread. Results of preoperative radiotherapy were similar to those of irradiation after surgery. Postoperative radiotherapy is favored, because it allows a selection of patients for extra treatment on the base of prognostic information, provided by the histologic characteristics of the neck dissection specimen.

Carcinoma, Squamous Cell↗

Perspectives of monoclonal antibodies for detection and treatment of head and neck tumours.

Monoclonal antibodies (mabs) are potentially powerful tools for the detection and treatment of cancer. To date, only a limited number of mabs are available to head and neck cancer. We produced 5 different groups of mabs to head and neck cancer. These mabs were characterized for their reactivity tumour and non-tumour tissues. Furthermore, biochemical elucidation of recognized antigens was provided. In animal studies the effectiveness of mabs for diagnoses and therapy of cancer is clearly demonstrated. The first results of a clinical study for the detection of head and neck cancer with mabs are shown. Finally, the future of mabs in clinical oncology is discussed.

Animals↗