Local vestibular blood flow and systemic vascular responses to natural vestibular stimulation in the Mongolian gerbil.

HYPOTHESIS: Natural stimulation of the vestibular end organs will produce alterations in the local vestibular microvascular blood flow. BACKGROUND: The vestibular and cardiovascular systems require a coordinated interaction to maintain organ perfusion during rapid positional and postural changes. However, the detailed relationship of these systems is not well understood. There have been no previous descriptions of local vestibular blood flow (VBF) during natural stimulation (NS) conditions. METHODS: In vivo VBF and systemic blood pressure (BP) in the Mongolian gerbil during natural stimulation. Using laser Doppler flowmetry, the authors obtained continuous measures of local VBF in both anesthetized and alert gerbils during sinusoidal rotational stimuli. Simultaneous recordings of systemic BP were collected from the contralateral common carotid artery. RESULTS: The anesthetized gerbils showed stable VBF and BP during all vestibular stimuli. By contrast, alert subjects demonstrated a significant response to natural stimulation. The VBF increased 28% over baseline, and systemic BP increased 8% during a 45-second, 0.133-Hz sinusoid. Decreases in BP of 8% and 5%, respectively, were seen with a 0.10 and 0.20 Hz, 360-second stimulus. A corresponding determination of VBF during the extended stimulus conditions was not technically possible. CONCLUSIONS: To the authors' knowledge, these are the first in vivo descriptions of vestibular blood flow during natural stimulation. In the alert animals, VBF increased in response to NS. This increase in flow does not appear to be directly dependent on systemic blood pressure changes and indicates that the vestibular microvasculature is closely regulated.

Functional outcomes of the retromaxillary-infratemporal fossa dissection for advanced head and neck/skull base lesions.

The retromaxillary-infratemporal fossa (RM-ITF) dissection, using a preauricular incision, was initially popularized for the treatment of temporomandibular joint disorders, facial fractures, and orbital tumors. This approach has been expanded for the treatment of advanced head and neck and skull base tumors extending into the infratemporal fossa. We studied prospectively eight consecutive patients requiring a RM-ITF dissection. Pre- and postoperative functional outcomes measured were mastication, speech, swallowing, cranial nerve function, pain, and cosmesis. A significant reduction in pain was noted postoperatively in all patients studied. Limited changes were identified in mastication, speech, swallowing, vision, hearing, or cosmesis postoperatively. The RM-ITF dissection should be considered when resecting advanced head and neck/skull base lesions that extend into this region. We have found minimal morbidity associated with this dissection. This procedure may have a useful place in palliation of patients with incurable pain caused by tumor invasion into the infratemporal fossa.

The effects of flunarizine and pentoxifylline on vestibular blood flow in the guinea pig.

Several authors have proposed that complications arising from vestibular disorders are the result of compromised circulation. The purpose of the current study was to assess the ability of flunarizine and pentoxifylline to increase peripheral vestibular blood flow (VBF), since flunarizine is a selective calcium-channel entry blocker that inhibits calcium-related contraction of smooth muscle, while pentoxifylline is a xanthine derivative that promotes microcirculation by affecting red blood cell malleability. Both of these treatment strategies have received considerable attention in clinics and laboratory, but their effects on blood flow are unclear. Changes in VBF were evaluated from the posterior semicircular canal ampulla in guinea pigs using a laser Doppler flowmeter. One group of animals was infused with pentoxifylline at concentrations of 10-40 mg/ml, while a second group was treated with 0.3-1.5 mg/kg flunarizine. VBF, blood pressure (BP) and heart rate (HR) were monitored continuously. Findings showed that pentoxifylline induced a concentration-dependent increase in VBF. In contrast, no increase in VBF occurred in response to flunarizine infusions. These studies suggest that the effectiveness of pentoxifylline in the clinical treatment of vestibular disorders may be the result of improved blood flow.

Nutritional and zinc status of head and neck cancer patients: an interpretive review.

In this review, we provide evidence based on our studies, for zinc deficiency and cell mediated immune disorders, and the effects of protein and zinc status on clinical morbidities in patients with head and neck cancer. We investigated subjects with newly diagnosed squamous cell carcinoma of the oral cavity, oropharynx, larynx, and hypopharynx. Patients with metastatic disease and with severe co-morbidity were excluded. Nutritional assessment included dietary history, body composition, and prognostic nutritional index (PNI) determination. Zinc status was determined by zinc assay in plasma, lymphocytes, and granulocytes. Pretreatment zinc status and nutritional status were correlated with clinical outcomes in 47 patients. Assessment of immune functions included production of TH1 and TH2 cytokines, T cell subpopulations and cutaneous delayed hypersensitivity reaction to common antigens. At baseline approximately 50% of our subjects were zinc-deficient based on cellular zinc criteria and had decreased production of TH1 cytokines but not TH2 cytokines, decreased NK cell lytic activity and decreased proportion of CD4+ CD45RA+ cells in the peripheral blood. The tumor size and overall stage of the disease correlated with baseline zinc status but not with PNI, alcohol intake, or smoking. Zinc deficiency was associated with increased unplanned hospitalizations. The disease-free interval was highest for the group which had both zinc sufficient and nutrition sufficient status. Zinc deficiency and cell mediated immune dysfunctions were frequently present in patients with head and neck cancer when seen initially. Zinc deficiency resulted in an imbalance of TH1 and TH2 functions. Zinc deficiency was associated with increased tumor size, overall stage of the cancer and increased unplanned hospitalizations. These observations have broad implications in the management of patients with head and neck cancer.

Effects of zinc and nutritional status on clinical outcomes in head and neck cancer.

The head and neck cancer patient often presents with both protein malnutrition and trace element deficiencies. Zinc has been found to be deficient in many head and neck cancer patients. In this study, pretreatment zinc status and nutritional status (measured by the Prognostic Nutritional Index [PNI]) were correlated with clinical outcomes in 47 patients. The patients were followed-up for a median of 52 mo from the time of enrollment. Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no such correlation was seen with PNI, alcohol intake, or smoking in our subjects. The results also showed that impaired zinc status was associated with an increased number of treatment morbidities, unplanned hospitalizations, and treatment delays (P < 0.05). Nutritional status was not associated with any studied outcome variable. The disease-free interval was highest for the group which had both zinc-sufficient and nutrition-sufficient status. Although our data do not prove conclusively, they do suggest that impaired zinc status at presentation may contribute to treatment morbidity, and that for an optimal mean disease-free interval, a sufficient zinc and nutritional status is required.

Zinc deficiency in head and neck cancer patients.

BACKGROUND: Although a great deal of attention has been given to protein and calorie malnutrition in patients with head and neck cancer, zinc status has not been assessed properly in such patients in the past. METHODS: In this study we characterized zinc status by cellular zinc criteria and assessed several measures of protein and calorie malnutrition in patients with head and neck cancer. We determined prognostic nutritional index (PNI) based on serum albumin, serum transferrin, triceps skin fold measures, and delayed hypersensitivity, as proposed by Buzby et al. In this study, the baseline zinc status and PNI of 60 head and neck cancer patients were correlated with the tumor size and overall stage of the disease. RESULTS: Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no correlation was seen with PNI, alcohol intake, or smoking in our study subjects. CONCLUSION: We conclude that zinc status is a better indicator of tumor burden and stage of the disease in head and neck cancer patients than the patients' overall nutritional status.

Timing of edentulation and extraction in the management of oral cavity and oropharyngeal malignancies.

BACKGROUND: Pretreatment dental evaluation is an essential element in the management of the head and neck cancer patient. Frequently, the dental condition requires edentulation or multiple extractions prior to radiotherapy. These extractions may be carried out at the time of oncologic resection. Such practice is routine for some surgeons but resisted by others who fear increased postoperative wound complications. To date, no study evaluating the safety and efficacy of extractions at the time of surgical resection has been reported. This paper retrospectively examines the postoperative course of head and neck cancer patients with varying strategies of dental management. METHODS: Retrospective analysis of patients with surgically treated oral cavity or oropharyngeal malignancies and dental extractions or edentulation at a tertiary oncology center from 1985 to 1994 was made. Postoperative wound infection, fistula, and length of stay data were compared for patients undergoing concurrent extraction and those having dental extractions in the postoperative period. RESULTS: Thirty-two patients underwent ablative resection with concurrent extraction, whereas 23 had postsurgical extractions. The infection and fistula rates were 16% and 9% in the concurrent group and 35% and 26% for patients having postsurgical extractions. Mean postoperative stays were significantly shorter for patients undergoing concurrent extraction (15 +/- 8 days) compared with those of the postsurgical group (27 +/- 14 days). CONCLUSIONS: Patients whose extractions were performed concurrent with the oncologic resection experienced fewer postoperative wound complications and had significantly shorter postoperative hospitalizations than did the postsurgical group.

Survival of composite chondrocutaneous grafts by vessel implantation: a study in the rabbit ear model.

Composite chondrocutaneous graft reconstruction or reattachment has limited applicability, is traditionally restricted to small segmental losses, and is dependent on the status of the recipient bed and graft periphery for successful revascularization. Surgical enhancement of composite graft survival was experimentally investigated in the rabbit ear model through transposition and appositional placement of an adjacent vascular pedicle. Fluorescein-derived surface-survival determinations, microangiographic vessel-counting methods, and histologic analysis were used to study the effects of vascular augmentation, pedicle design variations, and angiogenic substance in sixty 8-cm2, full-thickness auricular grafts. A statistically significant survival advantage was demonstrated for the implanted grafts, secondary to perivascular angiogenesis from the implanted pedicle.

Noncoordinate control of RNA, lipopolysaccharide, and phospholipid syntheses during amino acid starvation in stringent and relaxed strains of Escherichia coli.

The syntheses of RNA, lipopolysaccharides, and phospholipids were measured simultaneously in stringent and relaxed cells of Escherichia coli during normal growth or starvation for amino acids. The synthesis of all these molecules was inhibited by amino acid starvation, but the reduction in synthesis was not coordinated.