Tumor-resident Lactobacillus iners confer chemoradiation resistance through lactate-induced metabolic rewiring

Tumor microbiota can produce active metabolites that affect cancer and immune cell signaling, metabolism, and proliferation. Here, we explore tumor and gut microbiome features that affect chemoradiation response in patients with cervical cancer using a combined approach of deep microbiome sequencing, targeted bacterial culture, and in vitro assays. We identify that an obligate L-lactate-producing lactic acid bacterium found in tumors, Lactobacillus iners, is associated with decreased survival in patients, induces chemotherapy and radiation resistance in cervical cancer cells, and leads to metabolic rewiring, or alterations in multiple metabolic pathways, in tumors. Genomically similar L-lactate-producing lactic acid bacteria commensal to other body sites are also significantly associated with survival in colorectal, lung, head and neck, and skin cancers. Our findings demonstrate that lactic acid bacteria in the tumor microenvironment can alter tumor metabolism and lactate signaling pathways, causing therapeutic resistance. Lactic acid bacteria could be promising therapeutic targets across cancer types.

Quantitative Analysis of Acetyl-CoA, Malonyl-CoA, and Succinyl-CoA in Myocytes

Several analytical challenges make it difficult to accurately measure coenzyme A (CoA) metaboforms, including insufficient stability and a lack of available metabolite standards. Consequently, our understanding of CoA biology and the modulation of human diseases may be nascent. CoA's serve as lipid precursors, energy intermediates, and mediators of post-translational modifications of proteins. Here, we present a liquid chromatography-mass spectrometry (LC-MS) approach to measure malonyl-CoA, acetyl-CoA, and succinyl-CoA in complex biological samples. Additionally, we evaluated workflows to increase sample stability. We used reference standards to optimize CoA assay sensitivity and test CoA metabolite stability as a function of the reconstitution solvent. We show that using glass instead of plastic sample vials decreases CoA signal loss and improves the sample stability. We identify additives that improve CoA stability and facilitate accurate analysis of CoA species across large sample sets. We apply our optimized workflow to biological samples of skeletal muscle cells cultured under hypoxic and normoxia conditions. Together, our workflow improves the detection and identification of CoA species through targeted analysis in complex biological samples.

Augmenting Mitochondrial Respiration in Immature Smooth Muscle Cells with an ACTA2 Pathogenic Variant Mitigates Moyamoya-like Cerebrovascular Disease

ACTA2 pathogenic variants altering arginine 179 cause childhood-onset strokes due to moyamoya disease (MMD)-like occlusion of the distal internal carotid arteries. A smooth muscle cell (SMC)-specific knock-in mouse model (Acta2SMC-R179C/+) inserted the mutation into 67% of aortic SMCs, whereas explanted SMCs were uniformly heterozygous. Acta2R179C/+ SMCs fail to fully differentiate and maintain stem cell-like features, including high glycolytic flux, and increasing oxidative respiration (OXPHOS) with nicotinamide riboside (NR) drives the mutant SMCs to differentiate and decreases migration. Acta2SMC-R179C/+ mice have intraluminal MMD-like occlusive lesions and strokes after carotid artery injury, whereas the similarly treated WT mice have no strokes and patent lumens. Treatment with NR prior to the carotid artery injury attenuates the strokes, MMD-like lumen occlusions, and aberrant vascular remodeling in the Acta2SMC-R179C/+ mice. These data highlight the role of immature SMCs in MMD-associated occlusive disease and demonstrate that altering SMC metabolism to drive quiescence of Acta2R179C/+ SMCs attenuates strokes and aberrant vascular remodeling in the Acta2SMC-R179C/+ mice.

Noncanonical role of singleminded-2s in mitochondrial respiratory chain formation in breast cancer

Dysregulation of cellular metabolism is a hallmark of breast cancer progression and is associated with metastasis and therapeutic resistance. Here, we show that the breast tumor suppressor gene SIM2 promotes mitochondrial oxidative phosphorylation (OXPHOS) using breast cancer cell line models. Mechanistically, we found that SIM2s functions not as a transcription factor but localizes to mitochondria and directly interacts with the mitochondrial respiratory chain (MRC) to facilitate functional supercomplex (SC) formation. Loss of SIM2s expression disrupts SC formation through destabilization of MRC Complex III, leading to inhibition of electron transport, although Complex I (CI) activity is retained. A metabolomic analysis showed that knockout of SIM2s leads to a compensatory increase in ATP production through glycolysis and accelerated glutamine-driven TCA cycle production of NADH, creating a favorable environment for high cell proliferation. Our findings indicate that SIM2s is a novel stabilizing factor required for SC assembly, providing insight into the impact of the MRC on metabolic adaptation and breast cancer progression.

Mitochondrial structure and function adaptation in residual triple negative breast cancer cells surviving chemotherapy treatment

Neoadjuvant chemotherapy (NACT) used for triple negative breast cancer (TNBC) eradicates tumors in ~45% of patients. Unfortunately, TNBC patients with substantial residual cancer burden have poor metastasis free and overall survival rates. We previously demonstrated mitochondrial oxidative phosphorylation (OXPHOS) was elevated and was a unique therapeutic dependency of residual TNBC cells surviving NACT. We sought to investigate the mechanism underlying this enhanced reliance on mitochondrial metabolism. Mitochondria are morphologically plastic organelles that cycle between fission and fusion to maintain mitochondrial integrity and metabolic homeostasis. The functional impact of mitochondrial structure on metabolic output is highly context dependent. Several chemotherapy agents are conventionally used for neoadjuvant treatment of TNBC patients. Upon comparing mitochondrial effects of conventional chemotherapies, we found that DNA-damaging agents increased mitochondrial elongation, mitochondrial content, flux of glucose through the TCA cycle, and OXPHOS, whereas taxanes instead decreased mitochondrial elongation and OXPHOS. The mitochondrial effects of DNA-damaging chemotherapies were dependent on the mitochondrial inner membrane fusion protein optic atrophy 1 (OPA1). Further, we observed heightened OXPHOS, OPA1 protein levels, and mitochondrial elongation in an orthotopic patient-derived xenograft (PDX) model of residual TNBC. Pharmacologic or genetic disruption of mitochondrial fusion and fission resulted in decreased or increased OXPHOS, respectively, revealing longer mitochondria favor oxphos in TNBC cells. Using TNBC cell lines and an in vivo PDX model of residual TNBC, we found that sequential treatment with DNA-damaging chemotherapy, thus inducing mitochondrial fusion and OXPHOS, followed by MYLS22, a specific inhibitor of OPA1, was able to suppress mitochondrial fusion and OXPHOS and significantly inhibit regrowth of residual tumor cells. Our data suggest that TNBC mitochondria can optimize OXPHOS through OPA1-mediated mitochondrial fusion. These findings may provide an opportunity to overcome mitochondrial adaptations of chemoresistant TNBC.

Smoking Behaviors of General Educational Development (GED) Recipients

OBJECTIVE

Cigarette smoking is inversely associated with education, and despite this gradient effect, individuals with a General Educational Development (GED) diploma, obtained through a high school equivalency test, have the highest smoking prevalence. Considered the high school equivalency credential, it is unclear why individuals with a GED have a substantially higher smoking prevalence compared to high school graduates and dropouts. We conducted a qualitative study to understand life experiences, tobacco use patterns, and perceptions of tobacco among GED smokers and attitudes and behaviors around smoking cessation.

METHODS

We recruited 40 GED smokers aged 18 to 35 years and conducted surveys and semi-structured individual interviews. Transcripts were independently coded, then coding differences were resolved and reviewed by a third team member. We independently determined themes within and between codes and met to determine final themes.

RESULTS

GED recipients had many early life experiences and characteristics that made them highly vulnerable to tobacco dependence. With perceived high cognitive abilities, GED smokers were knowledgeable of many evidence-based smoking cessation strategies and were aware of health risks. Health risks and the financial burden of smoking were motivation to quit. The majority were uninterested or lacked confidence that nicotine replacement therapy, medications, counseling, or the quitline could help them quit. Nearly all were enthusiastic and confident that financial incentives had the potential to help them quit.

CONCLUSIONS

Research is needed to determine whether financial incentives could improve smoking cessation outcomes in this unique population with an unequal burden of smoking.

The safety and effectiveness of a long-acting transdermal fentanyl solution compared with oxymorphone for the control of postoperative pain in dogs: a randomized, multicentered clinical study

A prospective, double-blinded, positive-controlled, multicenter, noninferiority study was conducted to evaluate the safety and effectiveness of transdermal fentanyl solution (TFS) compared with oxymorphone for the control of postoperative pain in dogs. Five hundred and two (502) client-owned dogs were assigned to a single dose of TFS (2.7 mg/kg) applied 2–4 h prior to surgery or oxymorphone hydrochloride (0.22 mg/kg) administered subcutaneously 2–4 h prior to surgery and q6h through 90 h. Pain was evaluated over 4 days by blinded observers using a modified Glasgow composite pain scale, and the a priori criteria for treatment failure was a pain score ≥8 or adverse event necessitating withdrawal. Four TFS- and eight oxymorphone-treated dogs were withdrawn due to lack of pain control. Eighteen oxymorphone-treated, but no TFS-treated dogs were withdrawn due to severe adverse events. The one-sided upper 95% confidence interval of the difference between TFS and oxymorphone treatment failure rates was −5.3%. Adverse events associated with oxymorphone were greater in number and severity compared with TFS. It was concluded that a single administration of TFS was safe and noninferior to repeated injections of oxymorphone for the control of postoperative pain over 4 days at the dose rates of both formulations used in this study.

Cross-sensitization between cocaine and acute restraint stress is associated with sensitized dopamine but not glutamate release in the nucleus accumbens

Repeated administration of psychostimulant drugs or stress can elicit a sensitized response to the stimulating and reinforcing properties of the drug. Here we explore the mechanisms in the nucleus accumbens (NAc) whereby an acute restraint stress augments the acute locomotor response to cocaine. This was accomplished by a combination of behavioral pharmacology, microdialysis measures of extracellular dopamine and glutamate, and Western blotting for GluR1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor (AMPAR). A single exposure to restraint stress 3 weeks before testing revealed that enduring locomotor sensitization to cocaine was paralleled by an increase in extracellular dopamine in the core, but not the shell subcompartment, of the NAc. Wistar rats pre-exposed to acute stress showed increased basal levels of glutamate in the core, but the increase in glutamate by acute cocaine was blunted. The alterations in extracellular glutamate seem to be relevant, as blocking AMPAR by 6-cyano-7-nitroquinoxaline-2,3-dione microinjection into the core prevented both the behavioral cross-sensitization and the augmented increase in cocaine-induced extracellular dopamine. Further implicating glutamate, the locomotor response to AMPAR stimulation in the core was potentiated, but not in the shell of pre-stressed animals, and this was accompanied by an increase in NAc GluR1 surface expression. This study provides evidence that the long-term expression of restraint stress-induced behavioral cross-sensitization to cocaine recapitulates some mechanisms thought to underpin the sensitization induced by daily cocaine administration, and shows that long-term neurobiological changes induced in the NAc by acute stress are consequential in the expression of cross-sensitization to cocaine.

Effects of a 98% solution of glycerol or sterilization with ethylene oxide on FeLV in bone allografts and effects on bone incorporation of allografts in cats

OBJECTIVES

To compare virucidal effects and bone incorporation properties of cortical bone allografts transplanted into specific-pathogen-free (SPF) cats. Allografts consisted of untreated bone from a SPF cat (negative-control group) and bone from 5 FeLV-infected cats that was subjected to sterilization with ethylene oxide (ETO), preservation with glycerol, or no treatment (positive-control group).

SAMPLE POPULATION

Bones from the aforementioned groups and twenty 8-week-old SPF cats (5 cats/group) implanted with an allograft from 1 of the aforementioned groups.

PROCEDURE

After implantation, blood samples were collected weekly to monitor FeLV p27 antigen and antibody titers. Quantification of FeLV provirus was performed on blood samples at weeks 0, 4, and 8 and donor bone samples at time of implantation. Cats were euthanatized 8 weeks after transplantation, and graft sites were evaluated.

RESULTS

All results for negative-control cats were negative. All ETO group cats had negative results for antigen and provirus in blood, whereas 1 cat had a low antibody titer. Although 3 ETO-treated allografts were positive for provirus, the DNA appeared denatured. One cat in the glycerol group had positive results for all tests in blood samples. All glycerol-preserved allografts were positive when tested for provirus. All results for positive-control group cats were positive. Differences in incorporation of bone grafts were not observed.

CONCLUSIONS AND CLINICAL RELEVANCE

Glycerol preservation of FeLV-infected bone allografts did not eliminate transmission of retrovirus to recipients. In contrast, ETO sterilization appeared to denature DNA and prevent infection. Treatments did not affect incorporation of bone grafts in young cats.

Pelvic actinomycosis presenting as malignant large bowel obstruction: a case report and a review of the literature

Actinomycosis is an infrequent chronic infectious disease. In most cases the diagnosis is made postoperatively because of its unusual clinical presentation. Moreover, abdominal actinomycosis may mimic cancer, inflammatory bowel disease, or diverticulitis. Delay in diagnosis leading to inadequate management and unnecessary procedures has been reported. We report the case of a 49-year-old woman with large bowel obstruction secondary to extensive pelvic actinomycosis involving the rectosigmoid and cecum. She required emergency surgery, which involved both resection and colostomy. A review of the literature on abdominal actinomycosis during the last 50 years is also reported. Rarely has emergency surgery been described in this condition. Although the incidence of actinomycosis has decreased, the abdominal-pelvic form has been increasing over the past 10 years secondary to increased prolonged use of the intrauterine device. As the clinical spectrum of actinomycosis has dramatically changed, so have the therapeutic considerations. Aggressive surgical management in advanced cases with multiorganic involvement seems to have reemerged in recent years. Consideration of actinomycosis in a woman with prolonged use of an intrauterine device and symptoms of bowel obstruction could help to improve the preoperative diagnosis and management of this rare disease.

Bone grafts

Bone grafting provides a method of enhancing bone healing in veterinary orthopedic patients. Specifically, autogenous cancellous bone graft provides the cellular components and matrix proteins that can accelerate bone healing, dramatically. Allografts provide immediate mechanical support for fracture repair and patient function, but these grafts do not create the osteogenic environment seen with the use of autogenous cancellous bone graft. Xenograft bone implants may also hold a place for use in fracture management. With the advent of recombinant bone-derived tissue growth factor technology, bone grafting may some day become a practiced technique of the past. For now, however, bone grafting still holds a strong place in orthopedic surgery when dealing with bone defects in animals.

Gasless laparoscopic-assisted intestinal stoma creation through a single incision

Intestinal stoma creation has been performed using both open and laparoscopic surgery. However, each technique still has disadvantages. We created the intestinal stoma through one incision, with the use of the laparoscope in a gasless fashion. This method has not been reported previously. Fourteen adult patients underwent this technique between February 1996 and December 1998. Indications for stoma creation were for various anorectal disease processes, most commonly for purposes of hygiene in patients with spinal cord injury. The average operative time to perform the stoma was 58 (range, 15-78) minutes, with minimal blood loss (<35 ml). Follow-up ranged from 1 to 22 months. Two cases (14 percent) were converted secondary to severe adhesions. All nonconverted patients were able to tolerate a regular diet within two days of surgery. There was only one stoma-related complication. Two patients (14 percent) died of comorbidities during follow-up. In conclusion, the initial experience with gasless laparoscopic-assisted intestinal stoma creation through a single incision is encouraging. Patients requiring ostomy creation as a single intervention may benefit from this approach.

Staged laparoscopic resection for complicated sigmoid diverticulitis

Previous studies have utilized different regimens of laparoscopic surgery for treatment of both acute and chronic diverticular diseases. Our aims were to assert that laparoscopic-assisted sigmoid resection and anastomosis for sigmoid diverticulitis after acute attacks is safe and feasible, provided the inflammatory process has subsided. A chart review was undertaken of patients who underwent laparoscopic sigmoid resection after resolution of the acute attack of diverticulitis at hospitals affiliated with the University of Miami. Thirty-eight patients, median age 52 years, were identified. Laceration of the spleen was the only intraoperative complication (one patient). Seven patients (18%) were converted due to severe adhesions. Regular diet was tolerated on the third postoperative day, and the length of hospital stay was 4 days. No major complications or deaths occurred. In conclusion, laparoscopic surgery for sigmoid diverticulitis after resolution of the acute process seems safe and feasible and provides excellent immediate postoperative recovery.

Prospective comparison of four sampling methods (cystocentesis, bladder mucosal swab, bladder mucosal biopsy, and urolith culture) to identify urinary tract infections in dogs with urolithiasis

A prospective study was conducted on 27 dogs with recurrent urinary tract infections (UTIs) and urolithiasis. Four sampling methods (i.e., urine obtained by cystocentesis, bladder mucosal swab, bladder mucosal biopsy, and urolith) were compared to identify UTI. Identical culture results were obtained from urine collected by cystocentesis and from the swab of bladder mucosa. In the presence of a positive urine culture, the same organism also was cultured from the bladder mucosal biopsy and urolith. However, in the presence of a negative urine culture, an organism was cultured from the bladder mucosal biopsy or the urolith in 18.5% of the cases. Therefore, when the culture from urine obtained by cystocentesis is negative, it is recommended that aerobic cultures of a bladder mucosal biopsy and a urolith be performed in cases of urolithiasis.

Intraoperative endoscopy during colorectal surgery

In cases where preoperative studies may have been inadequate or could not be performed, intraoperative endoscopy (IOE) becomes an essential investigative tool for identification of synchronous lesions, of nonpalpable lesions, of sources of bleeding, and localization of lesions during laparoscopic colonic surgery. We report our experience with IOE, and describe our techniques of transabdominal colonoscopy. A review of the IOE performed in hospitals affiliated with the University of Miami was done. Fifty-eight patients received IOE from July 1994 to August 1996. There were 47 colonoscopies (38 transanal and 9 transabdominal), and 11 flexible sigmoidoscopies. Colorectal cancer, diverticulitis, inflammatory bowel disease, and lower gastrointestinal bleeding represented 83% of cases. In 10% of cases IOE changed the extent of the surgical procedure. There were no complications related to IOE. We conclude that in selected patients undergoing colorectal procedures, IOE is an essential tool. It can be performed safely, effectively, and rapidly.

Congenital conditions that lead to osteoarthritis in the dog

Several congenital arthropathies exist in the canine that can lead to the development of degenerative joint disease. Nevertheless, early diagnosis and treatment generally will afford the patient a favorable prognosis for limb function. There is still a great need to develop controlled studies to evaluate the long-term efficacy of many of the surgical and medical treatment modalities that are currently available and will be made available in the future to treat the patient with a congenital arthropathy.

Dissipation of heat during polymerization of acrylics used for external skeletal fixator connecting bars

OBJECTIVE

To determine the amount of heat conducted by transfixation intramedullary pins (IP) and Kirschner wires (KW) during polymerization of acrylics used for external skeletal fixator (ESF) connecting bars.

STUDY DESIGN

Thermal conduction was measured using thermistors applied to IP and KW surfaces during the polymerization phase of acrylics.

METHODS

Type II ESF were created from IP or KW placed into wooden dowels and plastic tubing used to create connecting bars filled with one of two types of acrylic (Acrylic Pin External Fixation System or Technovit, Jorgensen Laboratories, Loveland, CO). Thermistors were positioned on the acrylic column surface and on IP or KW surfaces 5 or 10 mm from the acrylic column. Five ESF test groups were created. The maximum temperature (Tmax) of the acrylic column (Tmax-A), IP (Tmax-IP), KW (Tmax-KW), and duration that Tmax-IP or Tmax-KW remained greater than or equal to 55 degrees C were calculated.

RESULTS

All IP and KW thermistors placed 5 mm from acrylic columns reached mean temperatures greater than 50 degrees C and had peak temperature ranges greater than 55 degrees C compared with all IP and KW thermistors placed 10 mm from the acrylic columns in all groups. Thermistors placed 5 mm from the acrylic column in two groups maintained temperatures greater than 55 degrees C for greater than or equal to 0.5 minute.

CONCLUSIONS

Acrylic columns positioned 5 mm from a thermistor on a IP or KW had the potential to reach or exceed temperatures that have been reported to cause thermal necrosis of tissues.

CLINICAL RELEVANCE

Acrylic Pin External Fixation System or Technovit acrylic connecting bars used in ESF designs have the potential to cause thermal injury to soft and bony tissue by thermal conduction along transfixation pins or wires.

Acquired conditions that lead to osteoarthritis in the dog

There are many acquired arthopathies that will result in some degree of osteoarthritis, even after proper management. Once the articular cartilage is damaged, it is unlikely that the architecture of the original cartilage surface will return to the normal conditions that existed prior to injury. The purpose of timely and meticulous management of traumatic joint events is to stop the progression of osteoarthritic development. When dealing with articular fractures or other forms of trauma to articular cartilage, three important principles to remember are anatomic reduction of the articular surfaces, stable fixation, and limited weight bearing on the affected limb as soon as possible after surgery. Even after strict adherence to these principles, the pet owner should always be warned that the animal will develop some degree of osteoarthritis in the affected joint at some future time; at that time, chronic medical management may be indicated.

Effect of volume variations on osteogenic capabilities of autogenous cancellous bone graft in dogs

OBJECTIVE

To evaluate the osteogenic effect of differing volumes of autogenous cancellous bone graft (ACBG) placed into partial cortical defects of the ulna.

ANIMALS

15 healthy, mature Beagles.

PROCEDURE

Weekly radiographic views of defects were obtained over 8 weeks and were analyzed for bone density by use of radiographic optical densitometry. Histologic sections were obtained 8 weeks after surgery and were planimetrically evaluated for area of total, lamellar, and woven bone.

RESULTS

Defects receiving 0.3 and 0.75 g of ACBG had rapid initial bone production, and dogs receiving 0.3 g of ACBG had faster bone ingrowth than did those receiving 0.1 g of ACBG or controls. Defects receiving 0.75 g of ACBG had a rate of bony ingrowth equal to 0.3 g of ACBG. There was no difference in the histomorphometric area fractions of total, lamellar, or woven bone between defects treated with 0.1 or 0.75 g of ACBG, and between grafted or control defects, 8 weeks after surgery.

CONCLUSIONS

Overfilling a cortical defect with ACBG does not enhance early osteogenesis within the defect, and underfilling will delay the onset of osteogenesis within the defect.

CLINICAL RELEVANCE

A volume of ACBG sufficient only to fill a cortical defect is required to obtain a clinical osteogenic effect from the graft.

4NQO carcinogenesis: a mouse model of oral cavity squamous cell carcinoma

BACKGROUND

A murine model of oral cavity carcinogenesis is needed to study the molecular aspects of malignant transformation. 4-Nitroquinoline-1-oxide (4NQO), a water-soluble carcinogen, produces squamous cell carcinoma in rodents. Protocols were designed to investigate the temporal aspects of neoplastic transformation.

METHODS

4NQO was applied topically to mouse palates for up to 16 weeks. Mice were observed and killed from 24 to 49 weeks.

RESULTS

A spectrum of lesions ranging from atypia to moderately differentiated invasive squamous cell carcinoma (SCC) was produced. The severity of the lesions corresponded to the duration of treatment and the length of observation. There was no gross or microscopic evidence of an inflammatory reaction to 4NQO. The lesions were focal and normal mucosa predominated in the treated mice.

CONCLUSION

4NQO reliably produced preneoplastic and malignant oral cavity lesions, which morphologically and histologically mimic human head and neck cancer. Lesions develop long after 4NQO exposure and without an inflammatory response. Thus, the model should be useful for molecular analysis of neoplastic transformation.

Pantarsal arthrodesis in dogs and a cat: 11 cases (1983-1991)

Bone plates applied to the cranial surfaces of the tibia, the tarsus, and the metatarsus were used in 10 dogs and 1 cat that underwent pantarsal arthrodesis. Lengthening plates were used in 7 dogs, and 2.7- and 3.5-mm dynamic compression plates were used in the remaining dogs and the cat. Radiography was used to determine whether bone plates became loose or broke, and whether the joint fused completely. Bone plates became loose in 5 dogs; mean time between surgery and development of radiographic evidence of plate loosening was 19.4 months. The bone plate used in the cat broke 4 months after surgery. Overall, 9 of 11 animals had evidence of complete bony fusion of the tarsus at the time of the last radiographic evaluation. One dog had incomplete healing of the talocalcaneocentral joint and another dog had incomplete healing of the tarsometatarsal joint.

Eustachian tube dysfunction and its sequelae in patients with cleft palate

The incidence of middle ear disorders in patients with cleft palate deformities was determined in a retrospective review of 110 children with palate or palate and lip involvement. Ages ranged from 2 months to 18 years and included patients with associated abnormalities such as Pierre Robin syndrome and Treacher Collins syndrome. Clinical manifestations of eustachian tube dysfunction were found in 79% in the form of effusions, retraction pockets, adhesions, and ossicular erosion. Only two patients had confirmed cholesteatoma formation. Despite the low incidence of acquired cholesteatoma in these patients, the frequent occurrence of other disorders that affect hearing warrants early and aggressive otologic management to prevent long-term sequelae.

HIV wasting syndrome in the United States

OBJECTIVE

To describe the characteristics of individuals > or = 13 years of age with HIV wasting syndrome in the United States and US territories.

DESIGN

Retrospective review of national AIDS case surveillance data.

METHODS

Data for the 147,225 individuals with AIDS reported to the Centers for Disease Control from 1 September 1987 to 31 August 1991 were reviewed. The frequency of HIV wasting syndrome and its association with demographic and exposure category variables and with other AIDS-indicator diseases were assessed.

RESULTS

A total of 10,525 (7.1%) had wasting syndrome as the only AIDS-indicator condition, and 15,726 (10.7%) had wasting syndrome plus at least one other AIDS-indicator condition. Patients with wasting syndrome as the only AIDS diagnosis were more likely to be female, to be black or Hispanic, and to have a mode of HIV exposure reported as injecting drug use, heterosexual contact, or transfusion/hemophilia. The proportion of AIDS patients reported with wasting syndrome varied by geographic distribution, ranging from 11% in the northeastern United States to 47% in Puerto Rico. The association between HIV wasting syndrome and Hispanic ethnicity was due to the much higher prevalence of wasting syndrome reported in Puerto Rican AIDS patients. The other AIDS-indicator conditions most strongly associated with wasting syndrome were isosporiasis, pulmonary candidiasis, esophageal candidiasis, HIV encephalopathy, chronic mucocutaneous herpes simplex, and coccidioidomycosis.

CONCLUSIONS

The association between HIV wasting syndrome and injecting drug use, and the significant racial/ethnic and geographic differences in prevalence of this AIDS diagnosis may reflect differences in diagnostic and reporting practices and/or access to medical care.

Effects of a fixed compression load on the osteogenic effect of autogenous cancellous bone grafts in dogs

A standardized cortical defect was created on the caudal cortex of the proximal portion of each ulna in 5 adult mixed-breed dogs. One gram of autogenous cancellous bone graft (ACBG) was obtained from the greater tubercle of the ipsilateral humerus. The cortical defect in the ulna of 1 limb was filled with 1 g of ACBG that had been compressed with 2-MPa pressure for 30 seconds. One gram of noncompressed ACBG was placed into the contralateral ulnar cortical defect. The compressed and noncompressed ACBG recipient sites were radiographed at weekly intervals. Dogs were euthanatized 8 weeks after surgery, and the ACBG recipient sites were harvested for histomorphometric analysis. Optical densitometry was performed on all radiographs. There was no significant difference between compressed and noncompressed ACBG with optical densitometry or histomorphometric analysis for total bone area. We concluded that there was no difference in osteogenic capability between compressed and noncompressed ACBG of equal mass.

Surgical and nonsurgical complications associated with cochlear prosthesis implantation

Relatively few complications have been reported for cochlear implant surgery in spite of a recent report detailing a complication rate of 11.8 percent. This report highlights both the surgical and nonsurgical complications we have encountered that have resulted in either replacement of the implanted prosthesis or compromise of the sound processing strategy employed by the external unit. These complications make a strong argument for the use of preoperative, intraoperative, and postoperative radiologic examinations. Since the complications reported herein have not been attributed to the implant device proper, we feel cochlear implantation remains a safe and effective procedure for those patients who are untreatable by traditional methods.

Impact of diagnosis-related groups on the quality of postoperative care of patients with neck dissections

Two hundred eighty patients underwent neck dissection over a 10-year period: 138 during the 5-year period before the institution of Diagnosis-Related Group (DRG) reimbursement and 142 during the 5 years after DRG regulations. A comparison of these two groups by site of tumor, stage of disease, histopathology, previous treatment, type of neck dissection, whether neck dissection was carried out alone or in combination with another procedure, presence of preexisting disease, postoperative complications, and mortality revealed no significant differences. A 35% reduction in the length of hospital stay from 16 to 10 days was identified in the post-DRG group with no detrimental effects on patient care. The variables found to have the greatest impact on length of hospital stay were the extent of operation and postoperative complications.

The resident selection process in otolaryngology-head and neck surgery

This study was undertaken to characterize the objective information available about applicants to otolaryngology-head and neck surgery residency positions, and to determine the influence of these factors on obtaining a residency position. Applicants to the otolaryngology-head and neck surgery programs at University of Utah, Salt Lake City, University of Texas Medical Branch, Galveston, and University of Louisville (Ky) were studied. Thirty-one variables were examined, representing demographic and academic factors. Excellent academic performance in medical school (as represented by medical school grade-point average greater than 3.4, National Board part I score greater than 650, class percentile rank greater than 85th percentile, honors grades in both junior medicine and surgery clinical clerkships, or [5] election to Alpha Omega Alpha) was significantly correlated with success in obtaining an otolaryngology-head and neck surgery residency position.

Epidermal growth factor binding and action on tympanic membranes

A significant percentage of tympanic membrane (TM) perforations require some form of therapy to heal. Topical application of epidermal growth factor (EGF), a potent mitogen for epidermal and mesodermal cells, promotes healing of injuries in tissues histologically similar to TM, such as cornea and skin. We evaluated TM as a target tissue for EGF action. Specific, high affinity receptors for EGF were detected in TM (Kd = 3.1 nM, 150 fmol receptor/mg protein). Autoradiography of iodine 125-EGF binding to intact TMs revealed that EGF receptors were present on cells in the stratified squamous epithelial layer and in the stromal/mucoepithelial layer. Repetitive treatment of perforated cat TMs with 20 micrograms of EGF formulated in saline induced substantial hyperplasia of epithelial and stromal layers compared to paired TMs treated with saline. A single treatment of perforated cat TMs with 50 micrograms of EGF formulated in a hydrogel or in shredded Gelfoam produced significantly (p less than .05) smaller perforations at 6 days following the operation compared to paired TMs treated with vehicles. These results demonstrate that TM is a target tissue for EGF and that topical treatment with EGF stimulates healing of TM perforations.

Are we teaching medical students what they need to know?

If our broad goal for undergraduate education is to prepare students for residency and the eventual practice of medicine, the specific knowledge and skills we teach should reflect those that will be required of them to perform well as residents and practicing physicians. To determine and compare priority goals and objectives, we surveyed otolaryngology educators, a representative group of physicians in practice, and a representative group of residents. Participants were asked to evaluate the level of knowledge and skills necessary for students to attain in various areas of otolaryngology by ranking each item by a score of 0 to 3 according to its required depth of knowledge or skill. A rank "order of importance" was developed based on mean scores. The highest-ranking areas of knowledge were otitis media, airway obstruction, tonsillitis, and croup/epiglottitis, whereas the highest-ranking skills were history and physical examination of the head and neck, throat cultures, and use of the otoscope and pneumatoscope. The lowest-ranking areas of knowledge were voice disorders and ear deformities, whereas the lowest-ranking skills were interpreting electronystagmograms and stapedial reflex testing. We review the findings of our survey and comment on their role in undergraduate curriculum planning for otolaryngology.

Magnetically evoked facial nerve potential

Facial nerve stimulation by electrical current is painful and tends to discourage serial studies. Transcutaneous magnetic stimulation of the facial nerve is painless, easily reproducible, and elicits facial muscle responses identical to electrical stimulation.

Nasal fractures. What to do for a successful outcome

Nasal trauma is common in both children and adults. Most nasal fractures are easily reduced and do not result in long-term discomfort or disfigurement. However, care must be taken to avoid delay of treatment, especially in children, and to identify any associated cervical, paranasal, or intracranial injuries. Septal hematomas are not uncommon following nasal fracture and should be treated as soon as detected. The most common long-term sequela of nasal trauma is septal deviation with partial obstruction of the airway.

Laser tonsillectomy and adenoidectomy

The use of the laser for performing tonsillectomy and adenoidectomy has proved to be a very effective method in terms of reducing postoperative pain, bleeding, and operative time. With use of the laser, most patients can be treated on an outpatient basis. However, the treating physician must balance the medical gains against the increase in cost for laser use before embarking on this approach for patient care.

Reassessment of high-frequency air-bone gaps in older adults

In order to assess whether a high-frequency air-bone gap characteristically exists in older adults, air- and bone-conduction thresholds were measured for 147 ears from subjects ranging in age from 19 to 87 years. Results indicated that there were no apparent age-related effects, as evidenced by the mean data, the SDs, and scatterplots showing individual data points. However, a small number of older adults did have high-frequency air-bone gaps. In order to gain a better understanding of underlying causes, additional subjects over 50 years of age with high-frequency air-bone gaps were recruited. Ear-canal collapse did not appear to be a predominant underlying factor. Cerumen obstruction, healed tympanic membrane perforations, and an apparent loosening in the middle-ear system all were observed in ears with high-frequency air-bone gaps.

Nasal turbinate resection for relief of nasal obstruction

Surgical correction of mechanical nasal airway obstruction is commonly attempted by means of septoplasty or submucous resection. In spite of these procedures, patients continue to present postoperatively with inadequate nasal airflow due to hypertrophied turbinates. Partial resection of turbinate mucosa, submucous turbinate resection, electrocautery and outfracture of turbinates provide additional improvement but are incomplete procedures. Total inferior turbinectomies have been performed on 40 patients over the past 5 years; 29 of these patients have been followed from 2 to 60 months postoperatively by clinical examination and by formal questionnaire. Twenty-five patients described a marked improvement of their nasal breathing, 3 had mild improvement, and 1 had no improvement at all. Only 1 patient, 1 year postoperatively, described excessive dryness, 2 described mild dryness, 3 described excessive secretions and none complained of foul smell or pain postoperatively. All patients had patent airways by clinical examination by at least 2 otolaryngologists. The inferior turbinates play a role in humidification and temperature regulation of inspired air. The removal of them, however, does not seem to be fraught with the morbidity which has heretofore been attributed to this procedure.

Acute upper airway obstruction in the adult. 1. Causative disease processes

Infectious processes that can cause acute upper airway obstruction in adults include Ludwig's angina, retropharyngeal infection, acute epiglottis, diphtheria, tetanus, and peritonsillar abscess. They are uncommon but potentially lethal. Ludwig's angina in particular quickly progresses to airway obstruction. In most cases, the mainstays of management are antibiotics, surgical drainage, and if necessary, airway maintenance by tracheostomy, cricothyrotomy, or nasotracheal or endotracheal intubation. Hereditary angioneurotic edema causes episodes of laryngeal edema that may lead to suffocation. In an acute episode the airway must be maintained by endotracheal intubation.

Acute upper airway obstruction in the adult. 2. Causative events

Acute obstruction of the upper airway can be caused by several events. With some, such as anaphylaxis and trauma, obstruction may not be immediate and the physician may be able to take steps to avert it. Intubation is a common cause of upper airway injury. The most serious complication of this procedure is chronic subglottic stenosis. Vocal cord paralysis may result from tumor or neck trauma but especially from neck or mediastinal surgery, and the vocal cords should always be examined before and after such surgery.

Ophthalmoplethysmography in head and neck surgery

Ophthalmoplethysmography (OPG) is a simple, noninvasive diagnostic test in which the cerebral hemispheric blood flow can be indirectly measured. Its use in head and neck surgery is invaluable because it enables the surgeon to predict preoperatively whether a patient will survive carotid artery resection. In a three-year period, nine patients have survived carotid resection on the basis of favorable OPGs, without a death or permanent neurologic complication. A comparison of the results of OPG testing with intraoperative measurement of internal carotid artery pressure showed close correlation in 14 of 20 patients who were tested. Lack of correlation in four patients can be explained by the circumstances of the intraoperative test. This study's findings demonstrate that this test has high clinical reliability.