Appraising the factors favouring uranium mobilization and associated health risk assessment in groundwaters of north-western India.

An attempt has been made in this study to evaluate the factors favoring the uranium mobilization into the groundwater of Northwest India using uranium isotope activity ratio (234U/238U), radon (222Rn) and environmental isotopes of water (2H, 18O and 3H). The values range from 23 - 597 µg/L for total uranium and 634-3210 Bq/m3 for radon and the corresponding annual effective dose is estimated to be 18.9-490 µSv/a and 6.2-31.5 µSv/a respectively. Uranium activity ratio (UAR) varies from 0.68 - 1.17 and maximum samples indicate secular equilibrium. Environmental isotopic data indicates that the source to groundwater is vertical percolation of rainwater in the case of shallow zone while regional flows from outcrop areas recharge the deep groundwater. A wide scatter is noticed in environmental 3H content (0.23-6.62 TU) indicating both fast and sluggish water flows. The UAR phase diagram suggests that leaching process controls the uranium mobilization into the groundwater. The correlations among UAR, uranium and Uexcess further indicate oxidative nature of leaching process. Statistical treatment of the obtained data along with available geochemical and isotope evidences suggest that source of uranium is common but the driving processes are different for shallow and deep zone. Influences of root zone CO2, oxic species from irrigation return flows and water level fluctuations are also evaluated. Low uranium, low UAR, low 3H and high 222Rn activity in deep zone suggest uranium being released from the roll front as well as transported from outcrop regions. This study highlights the application of uranium isotope ratio, radon and environmental isotopes in assessing vulnerability of alluvial aquifers towards uranium contamination.

Distribution of environmental tritium in rivers, groundwater, mine water and precipitation in Goa, India.

Tritium concentration in rivers, groundwater, precipitation and mine pits water, all over Goa state was characterized to find out spatial and temporal variability of tritium. Twenty four water samples were collected during pre-monsoon and post-monsoon and analyzed for their tritium concentration. The mean tritium concentration in surface and sub-surface hydrosphere is 2.5 (±0.6) TU. The mean concentration of tritium in rivers, groundwater, mines pits water and rain water are 2.9 (±0.5) TU, 1.95 (±0.5) TU, 2.5(±0.3) TU and 3.1(±0.1) TU respectively. The tritium distribution in all the samples shows modern precipitation (post-1950) component in surface and sub-surface hydrosphere of Goa. The HYSPLIT4.0 air mass trajectory model and atmospheric circulation pattern suggest that the moisture origin was from the Arabian Sea and this low tritium moisture is diluting the tritium concentration of surface hydrosphere near the coastal area. The tritium concentration in surface hydrosphere shows more and more enrichment as one move inland (i.e. away from the coast). Significant seasonal change is observed in the surface hydrosphere. The pre-monsoon samples showed higher tritium concentration than post-monsoon samples. This may be due to high rate of re-evaporation of water and a reduction in the supply of oceanic moisture during the summer (pre-monsoon).

Isotope investigation on groundwater recharge and dynamics in shallow and deep alluvial aquifers of southwest Punjab.

Groundwater samples collected from the alluvial aquifers of southwest Punjab, both shallow and deep zones were measured for environmental tritium (3H) and stable isotopes (2H and 18O) to evaluate the source of recharge and aquifer dynamics. The shallow groundwater shows wide variation in isotopic signature (δ18O: -11.3 to -5.0‰) reflecting multiple sources of recharge. The average isotopic signature of shallow groundwaters (δ18O: -6.73 ± 1.03‰) is similar to that of local precipitation (-6.98 ± 1.66‰) indicating local precipitation contributes to a large extent compared to other sources. Other sources have isotopically distinct signatures due to either high altitude recharge (canal sources) or evaporative enrichment (irrigation return flow). Deep groundwater shows relatively depleted isotopic signature (δ18O: -8.6‰) and doesn't show any evaporation effect as compared to shallow zone indicating recharge from precipitation occurring at relatively higher altitudes. Environmental tritium indicates that both shallow (3H: 5 - 10 T.U.) and deeper zone (3H: 1.5 - 2.5 T.U.) groundwaters are modern. In general the inter-aquifer connections seem to be unlikely except a few places. Environmental isotope data suggests that shallow groundwater is dynamic, local and prone to changes in land use patterns while deep zone water is derived from distant sources, less dynamic and not impacted by surface manifestations. A conceptual groundwater flow diagram is presented.

A novel orthotopic mouse model of head and neck cancer and lymph node metastasis.

Prognosis of head and neck squamous cell carcinoma (HNSCC) is largely determined by the extent of lymph node (LN) metastasis at diagnosis, and this appears to be controlled by cancer cell genetics. To examine the role of these genes in LN metastasis, we created a human-in-mouse orthotopic model of HNSCC and performed comparative microarray analysis of gene expression between populations of HNSCC cell lines derived before and after serial transplantation and in vivo metastasis in mice. Microarray analysis comparing the USC-HN3-GFP, USC-HN3-GFP-G1 and USC-HN3-GFP-G2 cell lines identified overexpression of genes implicated in epithelial-to- mesenchymal transition and the formation of cancer stem cells, including CAV-1, TLR-4 (Toll-like receptor 4), MMP-7 (matrix metalloproteinase 7), ALDH1A3, OCT-4 and TRIM-29. Ingenuity Pathway Analysis confirmed upregulation of respective gene signaling pathways in the USC-HN1-GFP-G2 cell line. Patient HNSCC samples from advanced stages overexpressed ALDH1A3, CAV-1 and MMP-7. Our results show that CAV-1, TLR-4, MMP-7, ALDH1A3, OCT-4 and TRIM-29 have increased expression in HNSCC cells selected for an enhanced metastatic phenotype and suggest that these genes may have an important role in the metastatic potential of HNSCC cells. Inhibition of these genes may therefore have prognostic and therapeutic utility in HNSCC.

Transoral robotic resection of oropharyngeal synovial sarcoma in a pediatric patient.

Localized synovial cell sarcomas are treated with surgical resection followed by chemo-radiation. Surgical resection of synovial sarcoma of the oropharynx and hypopharynx involves lip-splitting mandibulotomy resulting in treatment related morbidity. We report the successful use of Trans Oral Robotic Surgery for resection of localized synovial sarcoma of the lateral pharyngeal wall in a 15 year old patient. We were able to achieve negative surgical margins and avoid open surgery with its associated morbidity. At 2 years follow-up, patient is disease free, with no deficits in speech or swallowing functions and no cosmetic deformity.

Relationships between stem cells and cancer stem cells.

Stem cells have been shown to exist in a variety of tissues. Recent studies have characterized stem cell gene expression patterns, phenotypes, and potential therapeutic uses. One of the most important properties of stem cells is that of self renewal. This raises the possibility that some of the clinical properties of human tumors may be due to transformed stem cells. Similar signaling pathways may regulate self renewal in normal and transformed stem cells. These rare transformed stem cells may drive the process of tumorigenesis due to their potential for self renewal. There are important ramifications for clinical cancer treatment if the growth of solid tumors is at least partially dependent on a cancer stem cell population. In the cancer stem cell model, tumor recurrence may be due to the non-targeted stem cell compartment repopulating the tumor. If cancer stem cells can be prospectively identified and isolated, it should be possible to identify therapies that will selectively target these cells.

Molecular pathology of head and neck cancer.

Squamous cell carcinoma of the head and neck region (HNSCC) is the sixth most frequent cancer worldwide, comprising almost 50% of all malignancies in some developing nations. In the United States, 30,000 new cases and 8,000 deaths are reported each year. Survival rates vary depending on tobacco and alcohol consumption, age, gender, ethnic background, and geographic area. This variability reflects the multifactorial pathogenesis of the disease. Early detection and diagnosis has increased survival but the overall 5 year rate of 50% is among the lowest of the major cancers. Differences between normal epithelium and cancer cells of the upper aerodigestive tract arise from specific alterations in genes controlling DNA repair, proliferation, immortalization, apoptosis, invasion, and angiogenesis. These proteins include both tumor suppressors and activating oncogenes which regulate a wide variety of intracellular signaling pathways. Included in these pathways are growth factor receptors, signal transducers, and transcription factors which regulate DNA damage response, cell cycle arrest, and programmed cell death. In head and neck cancer, alterations of three signaling pathways occur with sufficient frequency and produce such dramatic phenotypic changes as to be considered the critical transforming events of the disease. These changes include mutation of the p53 tumor suppressor, inactivation of the cyclin dependent kinase inhibitor p16, and overexpression of epidermal growth factor receptor (EGFR). This review will focus on the molecular changes which occur in these pathways and how they contribute to the pathogenesis of HNSCC.

Frontotemporal reconstruction with hydroxyapatite cement and the radial forearm free flap.

BACKGROUND: Contemporary surgical reconstruction of extensive frontal and temporal bony and soft tissue defects requires the use of myocutaneous free flaps. These flaps are associated with donor site morbidity, lengthy operative time, and lack of rigid protection for the brain. To circumvent these problems, we introduce a new surgical technique for reconstruction of frontotemporal defects. OBJECTIVES: To evaluate and discuss hydroxyapatite and radial forearm free flap (RFFF) reconstructive options for patients with soft tissue and bony defects in the frontal and temporal regions after ablative cancer surgery. METHODS: Eight consecutive patients with extensive soft tissue and bony defects in the frontal and temporal regions underwent primary reconstruction with hydroxyapatite cement for replacement of bone, and the RFFF for soft tissue coverage. Patient follow-up ranged from 6 to 48 months. Outcome was determined in terms of immediate and delayed postoperative complications, donor site morbidity, and long-term aesthetic results. RESULTS: Excellent bony and soft tissue contour restoration was achieved in all patients. The bony and soft tissue volume was maintained throughout the follow-up period. One patient had a stroke. No other postoperative complications were encountered. Morbidity from RFFF harvest was minimum. CONCLUSIONS: The combination of hydroxyapatite cement and the RFFF is a viable alternative to the conventional myocutaneous free flap reconstruction of extensive frontotemporal defects. This technique provides excellent aesthetic results, provides rigid protection for the brain, produces minimal and well-tolerated donor site morbidity, and reduces operative time by avoiding intraoperative changes in patient position.

Audit of percutaneous endoscopic gastrostomy (PEG): a questionnaire survey of hospital consultants.

One of the commonest indications for PEG is nutritional support in dysphagia. We investigated the current practice of PEG insertion in South Wales (UK). A postal questionnaire was sent to hospital consultants with responsibility for acute medical/geriatric intake in the South Wales area. Eighty-eight of 114 (78.5%) responded. In 69 of 107 (65%) responses (Radiologists and Geriatricians also performed PEG in some hospitals) Gastroenterologists performed the insertion of PEG. Seventy-one (87%) always involved speech therapists before PEG insertion. Forty-five (55%) and 47 (57%) always involved dieticians and nurses, respectively. Eighty (92%) involved carers before PEG. Sixty-three (76%) used nasogastric feed for nutritional support before PEG. Thirty-six of 80 (45%) responses would wait more than 2 weeks before inserting PEG (range less than 7 days to more than 6 weeks). Five (6.5%) preferred long-term nasogastric feed to PEG. Twenty-five (30%) had definite knowledge of a PEG clinic in their hospital and 38 of 77 (49%) who responded to this question said there was no routine follow-up or were not aware about follow up of PEG patients. There is wide variation in the timing of PEG insertion and involvement of paramedical staff. More research needs to be undertaken to provide evidence so guidelines can be developed in this area. Follow up of patients with PEG is poor but current evidence suggests follow up of these patients may be worth while as some patients with dysphagic stroke can regain their swallow late.

Reconstruction of pharyngeal defects using AlloDerm and sternocleidomastoid muscle flap.

OBJECTIVE: To report our experience in reconstructing pharyngeal defects that cannot be closed primarily, using acellular dermal matrix (AlloDerm, LifeCell Corp., Branchburg, NJ) and sternocleidomastoid (SCM) muscle flap. STUDY DESIGN: Prospective, nonrandomized, nonblinded study in the setting of an academic tertiary care medical center. METHODS: Fourteen patients underwent reconstruction of through-and-through defects of partial pharyngectomy for squamous cell carcinoma using AlloDerm graft. Primary closure of the defects was not possible because of substantial loss of pharyngeal tissue. The graft was reinforced with superiorly based SCM muscle flap in 10 patients. The remaining four patients did not receive any flap. Eleven lesions involved the lateral pharyngeal wall, and three were piriform sinus lesions. Patients were followed for a period ranging from 3 to 20 months. Outcome measures were determined on several parameters including graft take rate, evidence of graft contracture, postoperative complications, resumption of diet, intelligibility of speech, and decannulation. All patients were evaluated by a speech pathologist by means of a bedside swallowing examination. Five patients had videofluoroscopic studies. The three patients with piriform sinus lesions underwent videostroboscopic examination to assess vocal cord function. RESULTS: There was a high success rate for graft take. Two patients developed postoperative fistulas that resolved with conservative management. One of the 10 patients with SCM flap and one of the 4 patients without SCM flap developed fistulas. Clinically significant graft contracture or pharyngeal stenosis was not observed in any patients. All patients resumed oral intake. Ten patients resumed a normal diet, two tolerated a soft diet, and two could take purees. Decannulation was successful in all patients. Two of the three patients with piriform sinus lesions had vocal cord palsies after surgery resulting in breathy dysphonia. They underwent type I thyroplasty for vocal rehabilitation. All patients had intelligible speech. CONCLUSIONS: Thick AlloDerm, reinforced with SCM muscle or cervical soft tissue, provides a useful alternative option for reconstruction of pharyngeal defects that cannot be closed primarily. It is safe and effective and provides excellent functional outcomes.

Psychiatric referrals in multispeciality hospital.

K.L.E.S. hospital is a new multispecialty referral hospital attached to J.N. Medical College, Belgaum. All psychiatric referrals numbering 338 over a period from 1.7.1996 to 30.6.1997 were retrospectively studied. Socio-demographic data, source and reason for referral, diagnosis and treatment advised were noted. More than two-third of the referrals were male patients and belonged to the productive age group of 16 years to 45 years. 83.17% of the patients were referred from general medicine, medicine allied and medical superspeclality departments. Unexplained physical symptoms was the commonest reason for referral (64.44%). The commonest psychiatric diagnosis was neurotic, stress related, somatoform disorders (45.54%). Next common diagnosis was mood disorders (20 92%). Need for more dialogue and interaction between the referring doctor and the psychiatric team member is strongly felt.

Endoscopic surgical management of sphenoid sinus disease.

OBJECTIVES: To assess the outcome of functional endoscopic sphenoid sinus surgery, and to determine the predictors of outcome. STUDY DESIGN: Retrospective chart review of 651 consecutive endoscopic sinus procedures performed between 1992 and 1997. SETTING: USC University Hospital, University of Southern California, Los Angeles. MATERIALS AND METHODS: Seventy-four patients (11.4% of all endoscopic procedures) with sphenoid sinus disease were selected. All 74 patients were mailed a sinusitis-specific questionnaire, and 46 of them (62.2%) responded. Outcome measures derived from clinician ratings were applied to all 74 patients, and those derived from self-report were applied to 46. Outcome measures were determined from patient questionnaires at a minimum of 6-month postoperative follow-up, operative complications, and clinician perceptual ratings. Patient questionnaires addressed general patient satisfaction, symptom score, and medication usage. A statistical analysis was performed using chi2 test, linear regression, and one-way nonparametric ANOVA. RESULTS: Favorable surgical outcomes based on general patient satisfaction (84.8%, n = 39) and clinician perceptual rating (78.4%, n = 58) were noted. Minor postoperative complications were noted in 10 patients (13.5%) and 8 patients (10.8%) needed revision endoscopic procedures during follow-up. Of the complications, eight (80%) occurred in revision endoscopic procedures. The use of an expanded, sinus-specific symptom score revealed far fewer favorable outcomes (56.5%, n = 26). Seven outcome predictors were established, although none of the predictors held for more than one of the six outcome measures used. CONCLUSION: Endoscopic sphenoid sinus surgery is safe and effective. An expanded symptom score is recommended to assess the outcome of this procedure.

Surgery of the salivary glands.

Surgery of the salivary glands evolved rapidly after a greater understanding of the anatomy and pathologic processes affecting them was achieved. This article reviews the general and neurovascular anatomy of the major salivary glands. Understanding the anatomy of the salivary glands is a cornerstone of competent salivary gland surgery. The surgical techniques, potential pitfalls of surgery, and avoidance of postsurgical complications have been highlighted. Recent advances in surgical techniques are also presented.

Managing the emergency airway in Le Fort fractures.

Le Fort fractures are a part of the facial fracture spectrum, sustained from significant forces of impact to the midface. The mechanism of airway obstruction in Le Fort fractures is attributed to midface instability with posterior inferior displacement into the oropharyngeal airway. Otolaryngologists often participate in the evaluation and management of such patients, securing the airway, if necessary. It is important, therefore, to understand the mechanisms responsible for acute airway obstruction in these types of fractures. A retrospective review of 64 cases of Le Fort fractures, representing a 3-year period, was performed to determine the factors responsible for acute airway obstruction. The review disclosed that airway obstruction is due most often to hemorrhage into the upper airway from multiple sources, with inability to handle blood and the oral secretions. An emergency airway was required by one third of the patients with Le Fort fractures in this review.

Use of a mechanical microvascular anastomotic device in head and neck free tissue transfer.

BACKGROUND: The use of mechanical microvascular anastomotic systems for free tissue transfer has previously been reported. Currently, a commercially available coupling device (3M Healthcare, St. Paul, Minn) is widely used for various microvascular free flaps. However, to our knowledge, there are no reports in the literature describing the efficacy of this particular device in regard to free tissue transfer in head and neck reconstruction. OBJECTIVE: To describe the surgical technique, limitations, and guidelines for application of this system for vascular anastomosis in head and neck free tissue transfer. DESIGN: The microvascular anastomotic device was used in 79 head and neck free flaps: radial forearm (n = 28), rectus abdominis (n = 27), fibula (n = 12), lateral thigh (n = 4), iliac crest (n = 3), gracilis (n = 2), jejunum (n = 1), pectoral (n = 1), and lateral arm (n = 1). Follow-up ranged from 6 months to 2.5 years. SETTING: Two major teaching/referral medical centers. PARTICIPANTS: Seventy-six patients ranging in age from 19 to 86 years. INTERVENTION: A total of 105 anastomoses (17 arterial and 88 venous) were performed. OUTCOME MEASURES: Anastomotic times and patency rates were evaluated. RESULTS: the anastomotic times ranged from 8 to 18 minutes for the arteries (average, 10 minutes) and from 4 to 16 minutes for the veins (average, 5 minutes). None of the flaps resulted in venous congestion due to thrombosis at the anastomosis. Two arterial anastomoses resulted in thrombosis, one of which was detected intra-operatively and successfully salvaged with conventional suture anastomosis. CONCLUSIONS: The patency rates with the microvascular anastomotic system appear to compare favorably with those of standard suture techniques. The major advantage is that the time of venous anastomosis is reduced, thereby decreasing the total ischemic time. An additional advantage is the ease with which anastomoses can be performed when the vessels are deep within a wound, where suture placement is difficult.

Temporal bone findings in Alzheimer's disease.

Sensorineural hearing loss has been reported in Alzheimer's disease (AD) and a topographically specific pattern of degeneration in the central auditory system has been described. Although peripheral visual and olfactory systems have been extensively studied, there is no report of peripheral auditory system abnormalities in AD patients. Comparison of temporal bones from eight AD patients with those from eight non-AD controls revealed a significant difference in the percentage of remaining hair cells, peripheral processes, and spiral ganglion cells in the basal cochlear turn but no significant differences in the overall percentage between the two groups. Furthermore, special stains (thioflavin S and Bielschowsky's silver impregnation) of temporal bone nervous tissue from AD patients did not show neuritic plaques and neurofibrillary tangles. It is unclear whether the differences between the two groups in the basal portion of the cochlea are due to AD or some other process, such as presbycusis. However, lack of significant degeneration in other parts of the cochlea and absence of neurofibrillary tangles and neuritic plaques in all eight patients may suggest that the peripheral auditory system, unlike the peripheral visual and olfactory systems, is not involved in AD. A larger sample of AD patients is necessary to clarify the peripheral auditory system findings in the present study.

Sensory recovery in noninnervated free flaps for head and neck reconstruction.

Recent studies have reported sensory recovery in innervated ("sensate") microvascular free flaps used for oromandibular reconstruction. To evaluate the efficacy of sensate free flaps used for head and neck reconstruction, the natural outcome of noninnervated flaps must be known. Data on the natural recovery of sensation in noninnervated head and neck free flaps are lacking in the literature. This study evaluates the degree of spontaneous sensory reinnervation in noninnervated microvascular free flaps used for reconstruction of a variety of head and neck defects. Eighteen flaps were evaluated--9 fibula osseocutaneous and 9 radial forearm. The fibula flaps were used to reconstruct composite defects of the mandible and oral cavity mucosa. The radial forearm flaps were used to reconstruct defects resulting from floor of mouth resection (3), total glossectomy (2), pharyngectomy (1), full-thickness cheek (1), and facial skin (2). Sensation to pinprick, light touch, and temperature discrimination were tested over the skin paddle at time intervals ranging from 6 to 24 months. The pattern of sensory reinnervation in these noninnervated flaps over time and by location is discussed.

Safety of thyroidectomy in residency: a review of 186 consecutive cases.

A retrospective review was performed to assess the surgical complications of thyroidectomy performed by otolaryngology residents under close supervision by faculty. One hundred eighty-six consecutive cases of thyroidectomy performed by the residents in the Department of Otolaryngology--Head and Neck Surgery at the University of Southern California were reviewed. Sixty-nine percent of thyroidectomies were performed for malignant or possible malignant diseases, and 31% were performed for benign conditions. Transient (less than 2 weeks in duration) hypocalcemia occurred in 26% of the patients; the vast majority of cases resolved within the first week. Five percent of the patients developed persistent hypocalcemia requiring prolonged replacement therapy. The incidence of unexpected postoperative permanent vocal cord paralysis was 0.9%. These complication rates are comparable to those in previously published large series on results of thyroidectomy. Thyroidectomy performed in an otolaryngology residency training program is a safe procedure when closely supervised by experienced faculty.