Sinonasal adenoid cystic carcinoma: the M. D. Anderson Cancer Center experience

BACKGROUND

Adenoid cystic carcinoma of the sinonasal tract is a rare cancer that accounts for 10% of all malignancies at this site. The objective of the current study was to evaluate prognostic factors, treatment outcomes, recurrence patterns, and survival rates for sinonasal adenoid cystic carcinoma.

METHODS

A retrospective chart review was performed at an academic tertiary referral center. Between 1990 and 2004, 105 patients were evaluated for adenoid cystic carcinoma of the sinonasal tract at a single institution. Demographics, presentation, anatomic site, Tumor, Lymph Node, Metastasis (TNM) classification, pathology, treatment, recurrences, and survival were evaluated.

RESULTS

One hundred five patients with adenoid cystic carcinoma were evaluated, including 58 women and 47 men. Their median age was 50 years, and the mean follow-up was 47 months. The maxillary sinus (47%) and the nasal cavity (30%) were the most common primary tumor sites. The majority of patients presented with T3/T4 (76.7%), N0 (98%), M0 (97%) disease. Eighty-four percent of patients underwent surgery and received postoperative radiation as treatment for their primary disease. The local recurrence rate was 30%, and the distant metastases rate was 38%. The 5-year overall survival and disease specific survival rates were 62.9% and 70.9%, respectively.

CONCLUSIONS

Adenoid cystic carcinoma of the paranasal sinuses is a rare disease, and the ideal treatment paradigm has yet to be defined. The current data suggested that surgical resection with postoperative radiation therapy offers durable local control and compares favorably with historic data. Although local recurrences develop in a significant percentage of patients, survival from this disease exceeds that of other sinonasal malignancies.

Survival in patients with synovial sarcoma of the head and neck: Association with tumor location, size, and extension

BACKGROUND

The medical literature on synovial sarcoma (SS) of the head and neck region is limited. Thus, we determined whether clinical characteristics and treatment were associated with recurrence and survival rates in patients with SS of the head and neck.

METHODS

We retrospectively identified patients with a pathologic diagnosis of SS of the head and neck at our institution (a large tertiary comprehensive cancer center) and compared recurrence and survival rates by clinical characteristics and treatment.

RESULTS

Forty patients with SS of the head and neck were identified from 1945 to 2004 (first case in 1968), representing <5% of all head and neck sarcomas seen at our institution during this time period. Twenty-three patients (58%) had the monophasic histologic subtype, 15 (38%) biphasic, and 2 unspecified. Most patients were male (73%), with a median age of 29 years. SS tumors were most commonly located in the neck (60%); thus, the most common symptoms were a neck mass and neck pain. No patients reported a history of radiation exposure. Higher disease-specific and overall survival rates were associated with upper aerodigestive tract location, tumors of < or =5 cm, and tumors did not extend into bone. Patients treated with surgery and adjuvant radiotherapy had higher survival and lower recurrence rates than did those treated with surgery alone or a combination of surgery, radiotherapy, and chemotherapy. This difference was not significant, and the subgroups were small, with substantial confounding by adverse prognostic factors.

CONCLUSIONS

SS of the head and neck is extremely rare, and our results should be viewed with caution given the relatively small group size and treatment over a 36-year period. Survival rates were associated with tumor location, size, and extension. Treatment of SS of the head and neck should be directed toward complete surgical resection. Given the known sensitivity of SS to contemporary chemotherapy, a multimodality approach should be considered in the perioperative setting, especially in high risk patients.

Primary Tracheal Malignant Neoplasms: The University of Texas MD Anderson Cancer Center Experience

BACKGROUND

Primary malignant neoplasms of the trachea are very rare and data relating to them are limited. This study was conducted to review the presentation, management, and outcomes of primary tracheal cancers at our institution, a large multidisciplinary cancer center.

STUDY DESIGN

Retrospective chart review was conducted for all patients found to have a pathologic diagnosis of primary tracheal malignancy.

RESULTS

Since 1945, 74 patients were diagnosed with primary tracheal cancers. Among these, 34 (45.9%) were squamous cell carcinomas, 19 (25.7%) were adenoid cystic carcinomas, and 21 (28.4%) were of other histologic types. Presenting symptoms were most frequently dyspnea (55.4%), hemoptysis (48.6%), cough (41.9%), and hoarseness (35.1%). Most patients (77.3%) were former or current smokers, particularly those with squamous cell carcinoma (93.3%). For the entire group of 74 patients, the 5-year disease-specific mortality rate was 72.9% and the 5-year all-cause mortality rate was 79.3%. Patients who had adenoid cystic carcinoma and those with cervical primaries had better rates of disease-specific and overall survival than others (p = 0.036 and 0.006 for the former patient group and p = 0.006 and 0.030 for the latter patient group). Among patients with incident disease treated at our institution (n = 45), those undergoing primary operation with adjuvant radiotherapy appeared to have better disease-specific and overall survival rates compared with those undergoing primary radiotherapy with or without chemotherapy (p = 0.0002 and 0.0003, respectively). Although those undergoing operation and receiving radiotherapy did better than those undergoing operation alone, the difference was not statistically significant.

CONCLUSIONS

Primary tracheal cancers are very rare, and our results should be viewed with caution, given that our population comprised a small heterogeneous group treated over a 60-year period. Although squamous cell carcinoma was the most common pathology in smokers, adenoid cystic carcinoma was more prevalent among nonsmokers. Operation with adjuvant postoperative radiotherapy is recommended for most patients.

Conservation laryngeal surgery versus total laryngectomy for radiation failure in laryngeal cancer

BACKGROUND

Total laryngectomy is the standard of care for surgical salvage of radiation failure in laryngeal cancer. However, the role of conservation laryngeal surgery in this setting remains unclear. The objective was to compare the efficacy of conservation versus total laryngectomy for salvage of radiation failure in patients who initially presented with T1 or T2 squamous cancer of the larynx.

METHODS

A 21-year retrospective analysis of patients who received surgery at a single comprehensive cancer center after definitive radiation therapy is reported. At recurrence, the patients were reevaluated and then underwent a total laryngectomy or, if possible, a conservation laryngeal procedure. The charts of 105 patients who failed radiation treatment for primary laryngeal cancer and who subsequently underwent surgical salvage were reviewed for this study. Eighty-nine were male (84.8%). The mean age was 60.3 years. The median follow-up time after surgery was 69.4 months. Most patients with recurrence after radiotherapy required total laryngectomy (69.5%; 73/105). Conservation laryngeal surgery was performed for 32 patients (31.5%). Concomitant neck dissections were performed on 45 patients (45.5%).

RESULTS

In 14 patients, local or regional recurrence developed after salvage surgery: 9 patients after total laryngectomy (12.3%; 9/73), and 5 patients (15.6%; 5/32) after conservation laryngeal surgery. This difference was not statistically significant, nor was there a difference in disease-free interval for the two procedures (p = .634, by log-rank test). Distant metastasis developed in 13 patients. Most developed in the setting of local and/or regional recurrence, but distant metastasis occurred as the only site of failure in 6 of the patients who had undergone total laryngectomy but in 1 of the conservation surgery patients treated for a supraglottic laryngeal cancer. The overall mortality for patients who underwent total laryngectomy was also higher: 73.74% (54/73) versus 59.4% (19/32) for patients who underwent a conservation approach (p = .011 by log-rank test).

CONCLUSIONS

Although conservation laryngeal surgery was possible in a few patients with local failure after radiotherapy, conservation laryngeal surgery is an oncologically sound alternative to total laryngectomy for these patients.

Functional outcomes after laryngopharyngectomy with anterolateral thigh flap reconstruction

BACKGROUND

We examined speech and swallowing outcomes and complications in patients with anterolateral thigh (ALT) flap reconstruction of cervical esophageal defects.

METHODS

We retrospectively reviewed 29 patients treated with laryngopharyngectomy and ALT flap reconstruction at The University of Texas M. D. Anderson Cancer Center from March 2002 to July 2004. We compared complication rates, nutritional intake, number of tracheoesophageal punctures (TEPs), speech fluency and use, operative defects, and radiotherapy effects.

RESULTS

Twenty-two patients had circumferential defects, and seven had partial defects. Twenty-four patients had radiotherapy. Eleven patients underwent TEP. Higher complication rates in patients after TEP compared with those without TEP were not statistically significant (p = .268). Ninety percent of patients with TEP spoke fluently. Ninety percent of all patients returned to oral alimentation without significant effect from TEP (p = 1.00), complications (p = 1.00), radiation therapy (p = 1.00), or surgical defect (p = .56).

CONCLUSIONS

The ALT flap successfully reconstructs laryngopharyngeal defects with excellent speech and swallowing results.

Selective vs Modified Radical Neck Dissection and Postoperative Radiotherapy vs Observation in the Treatment of Squamous Cell Carcinoma of the Oral Tongue

OBJECTIVES

To assess the role of selective neck dissection in patients with squamous cell carcinoma (SCC) of the oral tongue with advanced nodal disease, and to assess the role of postoperative radiotherapy in patients with SCC of the oral tongue with pathologically N1 necks.

DESIGN

Retrospective study of the medical records of all patients who underwent neck dissection for SCC of the oral tongue from January 1, 1980, to December 31, 1995. Median follow-up was 5.7 years.

SETTING

The University of Texas M. D. Anderson Cancer Center, Houston, a tertiary care cancer hospital.

PATIENTS

A total of 220 patients with SCC of the oral tongue who received surgical treatment of both the primary tumor and the neck and who had an identifiable type of neck dissection, no synchronous or metachronous lesions, and no evidence of local recurrence.

INTERVENTIONS

All patients underwent resection of the primary tumor and neck dissection. The extent of neck dissection was determined by surgeon preference. Some patients received radiotherapy to the neck as well.

MAIN OUTCOME MEASURES

Clinical and pathological nodal status, type of neck dissection, and use of radiotherapy. The end points evaluated included the regional control rates.

RESULTS

For clinically N+ patients, 5 of 45 treated with selective neck dissection and 1 of 19 treated with radical or modified radical neck dissection had recurrences in the ipsilateral neck. If only patients with significant tumor burden on final pathological examination (clinically N+/pathologically N2) are considered, 4 (25.0%) of 16 patients undergoing selective neck dissection had recurrences in the neck, while none of the 14 patients treated with radical or modified radical neck dissection had recurrences in the ipsilateral neck (P = .07). Of the 50 patients who had pathologically N1 disease, 25 received postoperative radiotherapy and 25 did not. Of the latter, 2 had recurrences in the neck, while none of the 25 patients who received radiotherapy had recurrences in the neck (P = .24).

CONCLUSIONS

Selective neck dissection may be sufficient for many N+ patients with SCC of the oral tongue, but some patients with extensive nodal disease may benefit from more aggressive treatment of the neck. Radiotherapy may be beneficial for all of the node-positive patients, but further studies are needed. Prospective, randomized clinical trials will be useful in further defining the role of selective neck dissection in the clinically N2 neck and radiotherapy in the N1 neck for patients with SCC of the oral tongue.

Functional Outcomes after Circumferential Pharyngoesophageal Reconstruction

OBJECTIVE

To determine functional speech and swallowing outcomes, morbidity, and complication rates after reconstruction of circumferential pharyngoesophageal defects using a jejunal versus an anterolateral thigh (ALT) flap.

STUDY DESIGN

Retrospective analysis.

METHODS

We reviewed the medical records of 58 patients with circumferential pharyngoesophageal defects, 27 with ALT flap reconstruction, and 31 with jejunal interposition. We compared complication rates, intensive care unit (ICU) and hospital stays, nutritional intake, number of tracheoesophageal punctures (TEPs) performed, TE speech fluency, and functional use. Modified barium swallow studies assessed swallowing physiology.

RESULTS

Patient characteristics were similar. Total flap loss occurred in one (3.7%) patient with an ALT flap and two (6.5%) patients with jejunal interposition (P = 1.000), fistula in two (7.4%) ALT patients and one (3.2%) jejunal patient (P = .5931), and anastomotic stricture in four (15%) ALT patients and six (19.4%) jejunal patients (P = .7371). ICU and hospital stays were greater for jejunal patients (P = .001, <.001, respectively). TEPs were performed in eight jejunal patients and nine ALT patients. Eighty-nine percent of ALT patients and 63% of jejunal patients were fluent, whereas 78% of ALT patients and 25% of jejunal patients used TE speech to communicate. Ninety-one percent of ALT patients and 73% of jejunal patients resumed oral intake (P = .151). The most common causes of dysphagia were impaired tongue base retraction (62% jejunum) and disordered motility (62% jejunum, 67% ALT).

CONCLUSIONS

For circumferential pharyngoesophageal reconstruction, the ALT flap results in similar complication rates, but shorter ICU and hospital stays, and better speech and swallowing compared with jejunal reconstruction.

Olfactory neuroblastoma: the 22-year experience at one comprehensive cancer center

BACKGROUND

Olfactory neuroblastoma (ONB) is a rare tumor arising from the olfactory neuroepithelium. There is no universally accepted staging system, and treatment approaches lack uniformity. We present one institution's experience with this tumor and the results of therapy.

METHODS

Thirty patients treated for ONB at The University of Texas M. D. Anderson Cancer Center between 1979 and 2002 were retrospectively reviewed. The diagnosis of ONB was histologically confirmed for each patient.

RESULTS

The mean follow-up was 7.32 years. In 77% of cases, patients received treatment with surgery followed by postoperative radiation therapy. Sixteen percent received chemotherapy as part of their initial treatment. Overall 5-year and 10-year survival rates were 89% and 81%, respectively. Nine patients whose disease was initially stage C had a recurrence. The mean time for recurrence was 4.67 years.

CONCLUSIONS

The M. D. Anderson Cancer Center approach to ONB is complete surgical resection, usually involving a craniofacial approach, with postoperative radiation therapy. This approach seems to be curative in early-stage disease. Late recurrence warrants long-term follow-up.

Molecular and clinicopathologic comparisons of head and neck squamous carcinoma variants: common and distinctive features of biological significance

To investigate, for the first time, the events associated with the phenotypic and clinical diversities of head and neck squamous carcinomas (HNSC), we performed molecular analyses on 92 primary tumors representing the entire spectrum of the morphologic subtypes using microsatellite markers at chromosome 3p, 4p, 8p, 9p, 11q, 17p, and 18q regions and correlated the results with the clinicopathologic features and patients' survival. Loss of heterozygosity (LOH) at D9S168 and D9S171 markers on chromosome 9p regions was commonly identified in all subtypes. Distinctive alterations in certain subtypes were noted at chromosomes 3p, 4p, 8p, and 11p regions. In general, less aggressive types (verrucous, papillary, and well-differentiated conventional) had a significantly lower LOH incidence than the more aggressive (basaloid, sarcomatoid, and high-grade conventional squamous carcinoma) categories. Significant association between LOH and age, stage, nodal status, and patient outcome was found. Survival analysis revealed that pathologic categorization (less versus more aggressive) and LOH at marker D11S4167 and D3S2432 are independent predictors of patients' survival. Our analysis also defined a set of limited markers that account for most of alterations within and across these tumor subtypes. Our study indicates that 1) certain genetic markers are common to all subtypes of HNSC supporting their early involvement in tumorigenesis, 2) inter- and intratumoral genetic differences evolve subsequently and may underlie their morphologic heterogeneity, 3) high incidence of LOH in certain regions characterizes aggressive tumors, 4) categorical classification and LOH at 11p and 3p regions independently correlated with patient survival, and 5) a limited set of markers identify the majority of genetic alterations in these tumors.

Matched-Pair Analysis of Survival of Never Smokers and Ever Smokers With Squamous Cell Carcinoma of the Head and Neck

Purpose

To compare survival rates between patients with squamous cell carcinoma of the head and neck (SCCHN) without a history of smoking (never smokers) and those with a current or previous history of smoking (ever smokers).

Patients and Methods

Fifty never smokers with newly diagnosed SCCHN were matched to 50 ever smokers according to sex, age, tumor site, overall stage, nodal stage, and treatment. Survival analysis was performed using Kaplan-Meier estimates. Matched-pair survival was compared using the Cox proportional hazards model.

Results

The never smokers had a greater overall survival (P = .020), disease-specific survival (P = .022), and recurrence-free survival (P = .016). Furthermore, matched-pair analysis demonstrated smoking was associated with a significant increase in risk of overall death (relative risk [RR] = 3.50; 95% CI, 1.14 to 10.77; P = .029), risk of death owing to disease (RR = 3.98; 95% CI, 1.11 to 14.33; P = .034), and risk of disease recurrence (RR = 3.29; 95% CI, 1.18 to 9.14; P = .023). Smoking was associated with three-fold increases in risk for overall death, death owing to disease, and recurrence after adjustment for cancer-associated symptom severity and alcohol use, but the 95% CI for these adjusted risk estimates each included the null.

Conclusion

Survival differed significantly between never smokers and ever smokers with SCCHN. These results are not substantively explained by differences in cancer-associated symptoms or alcohol use, but the CIs are wide and some imprecision remains. Regardless, possible fundamental differences in SCCHN between ever smokers and never smokers may exist, and further molecular characterization of these tumors is needed to determine whether biologic differences needing targeted therapies exist.

The role of postoperative adjuvant radiation therapy in the treatment of mucosal melanomas of the head and neck region

BACKGROUND

Mucosal melanoma of the head and neck is uncommon, and has a poor prognosis due to locoregional and distant failure. The optimal treatment paradigm for patients with this disease has yet to be determined.

OBJECTIVE

To compare the outcomes of patients treated with various commonly used protocols for mucosal melanoma of the head and neck.

DESIGN

Retrospective study.

SETTING

Academic tertiary referral center.

PATIENTS

The medical records of 48 consecutive patients treated at a single institution from January 1, 1985, to December 31, 1998, were reviewed.

INTERVENTIONS

Patients were treated with surgery alone, surgery and adjuvant radiotherapy, or surgery and biochemotherapy, with or without adjuvant radiotherapy.

MAIN OUTCOME MEASURES

The outcomes of disease recurrence and survival were correlated with the treatment received.

RESULTS

Twenty patients received surgical treatment alone; in 9 patients (45%), this treatment failed locoregionally, and 10 (50%) of the patients developed distant metastases. The 5-year survival rate was 45% (9 of 20 patients). Twenty-four patients received postoperative adjuvant radiotherapy; in 4 patients (17%), this treatment failed locally, and 11 (46%) of the patients developed distant metastases. The 5-year survival rate was 29% (7 of 24 patients).

CONCLUSION

The addition of radiotherapy tended to decrease the rate of local failure (P =.13), but did not significantly improve survival (P =.73), because of the high rate of distant metastatic disease.

Squamous cell carcinoma of the buccal mucosa: one institution's experience with 119 previously untreated patients

BACKGROUND

Squamous cell carcinoma (SCC) of the buccal mucosa is a rare, but especially aggressive, form of oral cavity cancer, associated with a high rate of locoregional recurrence and poor survival. We reviewed our institution's experience with 119 consecutive, previously untreated patients with buccal SCC.

METHODS

We reviewed the charts of 250 patients who were seen at The University of Texas M. D. Anderson Cancer Center between January, 1974, and December, 1993. Of these, 119 were untreated and were subsequently treated exclusively at our institution. Patients who were previously treated elsewhere or whose lesions arose in other sites and only secondarily involved the buccal mucosa were excluded.

RESULTS

Patients with T1- or T2-sized tumors had only a 78% and 66% 5-year survival, respectively. Muscle invasion, Stensen's duct involvement, and extracapsular spread of involved lymph nodes were all associated with decreased survival (p <.05). Surgical salvage for patients with locoregional recurrence after radiation therapy was rarely successful.

CONCLUSIONS

SCC of the buccal mucosa is a highly aggressive form of oral cavity cancer, with a tendency to recur locoregionally. Patients with buccal mucosa SCC have a worse stage-for-stage survival rate than do patients with other oral cavity sites.

Predictors of weight loss during radiation therapy

OBJECTIVE

To define risk factors for weight loss or dehydration during radiation therapy (RT).

STUDY DESIGN AND SETTING

Retrospective chart review, academic tertiary care center.

RESULTS

The incidence of severe weight loss during RT was 32.7%, the incidence of dehydration was 10.9%, and the rate of prophylactic feeding gastrostomy tube placement was 32%. The patients most likely to suffer severe weight loss included patients with tumor sites of nasopharynx and base of tongue, those treated with chemoradiation, and patients with severe pretreatment weight loss. Prophylactic feeding gastrostomy tube placement before RT significantly reduced the incidence of severe weight loss and hospitalization during RT.

CONCLUSION

Severe weight loss and dehydration during RT for head and neck cancer is common. Prophylactic feeding gastrostomy tubes significantly reduce the incidence of severe weight loss and hospitalization for dehydration during RT when placed before onset of RT. Patients at risk for severe weight loss include those with severe pretreatment weight loss, tumors of the nasopharynx and base of tongue, or treatment with chemoradiation.

The Drosophila GMII gene encodes a Golgi alpha-mannosidase II

In this paper we show the organisation of the Drosophila gene encoding a Golgi alpha-mannosidase II. We demonstrate that it encodes a functional homologue of the mouse Golgi alpha-mannosidase II. The Drosophila and mouse cDNA sequences translate into amino acid sequences which show 41% identity and 61% similarity. Expression of the Drosophila GMII sequence in CHOP cells produces an enzyme which has mannosidase activity and is inhibited by swainsonine and by CuSO(4.) In cultured Drosophila cells and in Drosophila embryos, antibodies raised against a C-terminal peptide localise this product mainly to the Golgi apparatus as identified by cryo-immuno electron microscopy studies and by antibodies raised against known mammalian Golgi proteins. We discuss these results in terms of the possible use of dGMII as a Drosophila Golgi marker.

Selective neck dissections for squamous carcinoma of the upper aerodigestive tract: patterns of regional failure

BACKGROUND

Surgeons have been using selective neck dissections in the treatment of squamous carcinoma of the upper aerodigestive tract for over 20 years. To date, no data is available that can answer the question "What are the patterns of failure in the neck following a selective neck dissection and is a selective neck dissection a reliable procedure for metastatic disease?"

METHODS

To answer this question, the medical records of all patients with squamous carcinoma of the oral cavity, oropharynx, larynx, and hypopharynx treated at The University of Texas M. D. Anderson Cancer Center from January 1, 1985-December 31, 1990, with a selective neck dissection were reviewed. Five hundred seventeen neck dissections were analyzed: suprahyoid (41), supraomohyoid (284), and anterolateral (192). The end point of the study was regional failure and survival.

RESULTS

Regional recurrence in patients treated with a suprahyoid dissection was 43% with pathologically positive nodes. The regional recurrence in the patients treated with a supraomohyoid neck dissection was 1.9% with pathologically negative nodes, 35.7% with path N1 without postoperative radiation therapy, and 5.6% with postoperative radiation therapy. The neck staged pathologically N2B failed with and without postoperative radiation, 8.3% and 14%, respectively. Thirteen percent of the anterior/lateral neck dissections failed regionally. If multiple pathologically positive nodes (N2B) were present, the regional failure with postoperative radiation was 30% and 33.3% without postoperative radiation.

CONCLUSION

The results of this retrospective study suggest that a selective neck dissection is a satisfactory staging procedure and is a definitive operation if all the nodes are pathologically negative. However, if a node is found to be invaded with cancer, the use of postoperative radiation is advisable.

Mutant analysis reveals an alternative pathway for N-linked glycosylation in Drosophila melanogaster

The mas-1 gene of Drosophila melanogaster encodes Golgi mannosidase I (MAS-1), and flies homozygous for small deletions of the gene are viable. They show but few abnormalities and those have a low penetrance [Kerscher, S., Albert, S., Wucherpfennig, D., Heisenberg, M. & Schneuwly, S. (1995) Dev. Biol. 168, 613-626]. Here we sequence the N-linked oligosaccharides associated with a reporter protein, and with membrane proteins prepared from wild type and MAS-1 null organisms. The results show that the null organisms synthesise the same range of oligosaccharides as wild type, albeit with different ratios. There is an accumulation of the Man8GlcNAc2 which is one of the substrates for the MAS-1 enzyme. This supports the suggestion of Kerscher et al. that the lack of severe phenotypic disturbances in the null organisms is due to the presence of an alternative pathway(s), but it also shows that this alternative pathway(s) does not entirely compensate for the normal pathway.

The soluble alpha-mannosidases of Drosophila melanogaster

The alpha-mannosidases are implicated in both the catabolism of carbohydrates and the N-linked glycosylation pathway in insects, but little is known of the biochemistry of these glycosidases. In order to study the soluble alpha-mannosidases of Drosophila melanogaster we have used artificial fluorogenic substrates for detection of activity in situ following non-denaturing gel electrophoresis. This approach also permitted examination of the mannosidases present in different tissues and the sensitivity of the enzymes to known mannosidase inhibitors. Fluorogenic substrates were also used to determine the pH optima of partly purified mannosidases. We report that D. melanogaster contains several soluble alpha-mannosidase activities. Acidic mannosidases were detected in the gut, fat body and haemolymph of third-instar larvae. The major activity detected in larval guts was a neutral mannosidase presumed to be involved in digestion.

Nucleotide sequence of a Drosophila melanogaster cDNA encoding a calnexin homologue

A cDNA which encodes a calnexin (Cnx)-like protein from Drosophila melanogaster has been characterized. The deduced amino acid sequence shares several regions of homology with Cnx from other sources with two conserved motifs each repeated four times. The gene was found to be transcribed in various tissues and at all developmental stages. We have mapped the gene at chromosomal position 99A and we have also mapped the related gene coding for Drosophila calreticulin at 85E.

AGI, a previously unreported D. melanogaster alpha-glucosidase: partial purification, characterization, and cytogenetic mapping

Inbred Drosophila melanogaster stocks were surveyed for alpha-glucosidases with nondenaturing gel electrophoresis using a fluorogenic substrate to stain the gels. The glucosidase most active under these conditions is polymorphic. We established that the polymorphism is genetic in origin and that the glucosidase was not likely to be a previously characterized enzyme. The gene encoding the enzyme was mapped cytogenetically to 33 A1-2- 33A8-B1, confirming that this is an enzyme not yet reported in D. melanogaster. The enzyme was partially purified by elution from nondenaturing gels, which enabled us to establish that it has optimal activity at pH 6 and interacts most strongly with alpha-1-4 glucosides. A developmental and tissue survey suggested that this enzyme could have a purely digestive role or be involved in carbohydrate metabolism inside the organism. We propose that this enzyme is involved in either starch digestion or glycogen metabolism.

Acemannan-containing wound dressing gel reduces radiation-induced skin reactions in C3H mice

PURPOSE

To determine (a) whether a wound dressing gel that contains acemannan extracted from aloe leaves affects the severity of radiation-induced acute skin reactions in C3H mice; (b) if so, whether other commercially available gels such as a personal lubricating jelly and a healing ointment have similar effects; and (c) when the wound dressing gel should be applied for maximum effect.

METHODS AND MATERIALS

Male C3H mice received graded single doses of gamma radiation ranging from 30 to 47.5 Gy to the right leg. In most experiments, the gel was applied daily beginning immediately after irradiation. To determine timing of application for best effect, gel was applied beginning on day -7, 0, or +7 relative to the day of irradiation (day 0) and continuing for 1, 2, 3, 4, or 5 weeks. The right inner thigh of each mouse was scored on a scale of 0 to 3.5 for severity of radiation reaction from the seventh to the 35th day after irradiation. Dose-response curves were obtained by plotting the percentage of mice that reached or exceeded a given peak skin reaction as a function of dose. Curves were fitted by logit analysis and ED50 values, and 95% confidence limits were obtained.

RESULTS

The average peak skin reactions of the wound dressing gel-treated mice were lower than those of the untreated mice at all radiation doses tested. The ED50 values for skin reactions of 2.0-2.75 were approximately 7 Gy higher in the wound dressing gel-treated mice. The average peak skin reactions and the ED50 values for mice treated with personal lubricating jelly or healing ointment were similar to irradiated control values. Reduction in the percentage of mice with skin reactions of 2.5 or more was greatest in the groups that received wound dressing gel for at least 2 weeks beginning immediately after irradiation. There was no effect if gel was applied only before irradiation or beginning 1 week after irradiation.

CONCLUSION

Wound dressing gel, but not personal lubricating jelly or healing ointment, reduces acute radiation-induced skin reactions in C3H mice if applied daily for at least 2 weeks beginning immediately after irradiation.

Cloning and sequence analysis of GmII, a Drosophila melanogaster homologue of the cDNA encoding murine Golgi alpha-mannosidase II

Using the murine cDNA that encodes Golgi alpha-mannosidase II (GlcNAc transferase I-dependent alpha 1,3[alpha 1,6] mannosidase; EC 3.2.1.114) as a probe to screen a cDNA library made from Drosophila melanogaster (Dm) embryos, we have isolated GmII, the Dm sequence homologue. The 3926-bp cDNA has an open reading frame of 3327 bp and predicts a polypeptide of approx. 127 kDa, a mass similar to that of the murine protein. The deduced mouse and Dm amino acid (aa) sequences share extensive similarity across their entire lengths and are both type-II transmembrane (TM) proteins with short cytoplasmic tails, single TM domains and large hydrophilic C-terminal domains. A region of approx. 200 aa, within the C-terminal domain, has considerable similarity to a corresponding region from several other alpha-mannosidases. GmII has been localized to a single site (85D14-18) on the right arm of chromosome 3.

Interleukin-1 dose, mouse strain, and end point as they affect protection of mouse jejunum

Interleukin 1 (IL-1) has been shown to protect a number of normal tissues against radiation injury. In mouse jejunum, modest protection against radiation injury has been reported using only the in vivo crypt survival assay in one mouse strain. The major goal of this study was to determine the protective effect of IL-1 on mouse jejunum using two assays of damage, crypt cell survival and lethality from radiation-induced crypt cell depletion, in two mouse strains, C3Hf/Kam and BALB/c nu/+, which were bred and maintained in a specific-pathogen-free barrier colony. In addition, the dependence of protection on the IL-1 dose in both assays was determined. Our findings showed that IL-1 protection of crypt cell depletion and subsequent death of the animals from loss of these cells was dependent on the IL-1 dose. We found that the amount of protection by IL-1 was related to the criterion used to assess the protection. For example, if protection was determined as a ratio of D10's or LD50/10, a bigger DMF was obtained for BALB/c mice than C3H mice with the same IL-1 dose, suggesting that C3H mice were not as well protected. However, if protection was determined by the increase in crypt cell number after IL-1, there was an identical 2.4-fold increase in crypt cells after the same IL-1 dose in both strains. On the basis of this criterion, then, protection of crypt cells by IL-1 did not depend on the mouse strain. Although the effect of IL-1 on animal survival at 10 days was strain dependent, the difference was related to differences in the slopes of the respective crypt cell survival curves for the two strains and not to different effects of IL-1 in the two strains tested.

Flexible casts used in making indirect interim restorations

This article describes a procedure for making indirect interim restorations from a cast and dies made of polyvinyl siloxane impression material. The use of these flexible casts and dies facilitates the removal of the polymerized resin from the cast and the rapid set of the polyvinyl materials reduces the time involved in making the indirect interim restorations.

Detection of the lipid-linked precursor oligosaccharide of N-linked protein glycosylation in Drosophila melanogaster

The presence of a glycan of the same molecular size as the lipid linked precursor oligosaccharide (Glc3Man9GlcNAc2) of the N-linked protein glycosylation pathway in mammalian cells has been detected in a glycolipid fraction of cultured Drosophila melanogaster cells. Oligosaccharide sequencing studies were consistent with the existence of a glucosylated high mannose containing structure, which may be the common precursor for N-linked protein glycosylation in insect cells.