Describing the appropriate use and interpretation of odds and risk ratios.

In sport medicine, epidemiology of sport-related injury provides the foundation for understanding what types of injuries and illnesses occur and who is at the highest risk. Thus, accurate and transparent reporting and interpretation of risk metrics is essential to sports epidemiology. Odds ratios (OR) and risk ratios (RR) are two statistics used to quantify the association between exposure and outcome and are frequently seen in sports medicine literature. While similarities exist, there are optimal ways to use and interpret OR and RR based on the study design and outcome incidence in the target population. In this short communication, we will present common study designs (e.g. prospective cohort, case-control, cross-sectional) along with recommendations for the use and interpretation of OR and RR. This will ultimately assist practitioners in choosing and interpreting these frequently confused measures of association and also help journal reviewers better understand the appropriate use of these measures when evaluating a manuscript.

The diagnosis of intraabdominal visceral injury.

This article outlines the different modalities that have been used for the diagnosis of intraabdominal visceral injury. The methods span decades, and their development was driven by the need to provide an accurate and rapid diagnosis of intraabdominal injury for the patient. Some of these modalities parallel the explosion in technology. Each has been validated and criticized but eventually had developed its own "niche" in the assessment of the injured patient. Finally, they have all withstood the test of time.

Mutation in the alpha-synuclein gene identified in families with Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder with a lifetime incidence of approximately 2 percent. A pattern of familial aggregation has been documented for the disorder, and it was recently reported that a PD susceptibility gene in a large Italian kindred is located on the long arm of human chromosome 4. A mutation was identified in the alpha-synuclein gene, which codes for a presynaptic protein thought to be involved in neuronal plasticity, in the Italian kindred and in three unrelated families of Greek origin with autosomal dominant inheritance for the PD phenotype. This finding of a specific molecular alteration associated with PD will facilitate the detailed understanding of the pathophysiology of the disorder.

Percutaneous tracheostomy: one center's experience with a new modality.

BACKGROUND: A retrospective review of our experience with percutaneous tracheostomy was performed to determine our complication rate and pattern of use since this modality was introduced at our institution. METHODS: A retrospective chart review captured all patients in whom tracheostomy was performed or supervised by a trauma/critical care faculty member. Dates of hospital admission, ICU admission, intubation, discontinuation of mechanical ventilation, type and location of procedure, procedural complications, Injury Severity Score, charges, and patient demographics were collected. Percutaneous tracheostomy (PT) and open tracheostomy (OT) experiences were compared. RESULTS: Three hundred sixty-eight tracheostomies were performed (190 OT and 178 PT). The average time to tracheostomy (TTT) for PT patients decreased from 12.7 to 7.4 days. The average TTT for OT patients remained stable at 14.0 days. The complication rate was 3.5%, with 4 complications (1.5%) associated with OT and 9 complications (5.1%) associated with PT. All complications in the PT group occurred before using a single dilator system. The 9 complications in the PT group occurred among 5 surgeons, all before their 11th attempt. PT saves 444 dollars in charges per procedure. CONCLUSION: OT continues to be a safe method of performing tracheostomies. PT has a steep learning curve but can be mastered quickly. Benefits include a shorter time to tracheostomy, elimination of patient transport, and saving in charges. Initial PT attempts should be supervised by an experienced surgeon.

A novel putative low-affinity insulin-like growth factor-binding protein, LIBC (lost in inflammatory breast cancer), and RhoC GTPase correlate with the inflammatory breast cancer phenotype.

Inflammatory breast cancer is a rapidly growing, distinct form of locally advanced breast cancer that carries a guarded prognosis. To identify the genes that contribute to this aggressive phenotype, we compared under- and overexpressed sequences in an inflammatory breast tumor cell line with those of actively replicating normal human mammary epithelial cell lines using differential display. Of the 17 transcripts isolated and characterized from these experiments, overexpression of RhoC GTPase and loss of expression of a novel gene on 6q22, LIBC (lost in inflammatory breast cancer), were highly correlated (P<0.0095 and P<0.0013, respectively) with the inflammatory phenotype when a panel of archival inflammatory breast cancers was compared with noninflammatory stage III breast cancers by in situ hybridization. This study suggests two new molecular markers specific for inflammatory breast cancer.

Contig map of the Parkinson's disease region on 4q21-q23.

We have constructed a yeast artificial chromosome contig (YAC) map of human chromosome 4q21-q23 across the Parkinson's disease region by combining molecular and fluorescence in situ hybridization techniques. This map contains 55 YACs and 51 molecular markers, including 23 polymorphic markers. We have also isolated one P1 and 33 bacterial artificial chromosomes located within this contig. Plasmid libraries were generated from 11 of these BAC and P1 clones, and 614 random plasmid clones were sequenced for a total of about 200 kb. This contig allowed us to precisely determine the location of 18 transcripts within the D4S2460-D4S2986 interval, including the alpha-synuclein gene found to be mutated in some families with Parkinson's disease.

Morbidity and mortality of carotid endarterectomy: rates of occurrence in asymptomatic and symptomatic patients.

During a six-year period ending December 1979, a retrospective study of 252 carotid endarterectomies in 211 patients was undertaken to review morbidity and mortality, and factors related to them. For purposes of the study, patients were categorized into asymptomatic and symptomatic groups. Indications for operation were internal carotid artery stenosis that occluded 50% or more of the vessel, an ulcerated plaque proved by angiography, or both. There were no postoperative deaths or neurological complications in the asymptomatic group. In the symptomatic group, there was an overall postoperative mortality of 2% and a stroke rate of 2%. All postoperative CNS deaths and strokes occurred in patients in whom there was difficulty in controlling blood pressure postoperatively. We conclude that with regard to carotid endarterectomy for treatment of extracranial occlusive disease (1) there is an acceptable morbidity and mortality in the symptomatic patient, (2) in the asymptomatic patient the procedure is associated with minimal complications, and (3) strict control of blood pressure in the immediate postoperative period is a critical factor in preventing neurological morbidity and mortality.

Is exploratory celiotomy necessary for all patients with truncal stab wounds?

Mandatory exploratory celiotomy was carried out in 1241 consecutive patients with truncal stab wounds. Four hundred seventy-one (38%) patients who had no intra-abdominal injury identified at operation developed 16 complications (3%), with one patient (0.2%) dying postoperatively. The average length of hospitalization (5 days) was increased if the patient: (1) required a simultaneous operation for associated site injuries (9 days), (2) developed postoperative complications (16 days), or (3) required reoperation (27 days). The 1990 projected cost per patient for routine celiotomy has increased 92% over that seen 10 years ago. Selective management protocols using observation, repeated physical examination, and special diagnostic procedures could be instituted for asymptomatic hemodynamically stable patients with truncal stab wounds if appropriate facilities and personnel are available. Successful implementation should preserve medical resources for those patients with trauma requiring a life-saving operation.

Diagnosis and management of major tracheobronchial injuries.

From 1968 to 1978, 14 patients were treated for major tracheal or bronchial injury. Five injuries resulted from blunt trauma and nine from penetrating injury. Of the 5 patients with injury due to blunt trauma, three had avulsions of the right main bronchus from the trachea. In 2 of them, the injury was associated with stellate tears of the distal trachea and bronchus. The simple avulsion was repaired by a primary anastomosis of the right main bronchus to the distal trachea. For the other 2 patients, treatment consisted of right pneumonectomy. The remaining 2 patients in this group had complete transection of the trachea and underwent primary repair. Of the 9 patients with a penetrating injury, 4 had lacerations of the cervical trachea which were treated with neck exploration and tracheostomy. Three patients with partial transections of the cervical or upper mediastinal trachea were treated by primary closure. The other 2 patients had gunshot wounds to the distal right lateral trachea, which were treated by right thoracotomy and primary closure. There were no deaths, and the subsequent course was generally good in all patients.

The continuing challenge of popliteal vascular injuries.

During a 6 year period, 35 patients with 56 popliteal vascular injuries were treated. Thirty-three arteries and 23 popliteal veins were affected. Fifty-four percent of the patients had both an arterial and a venous injury. Twenty injuries were due to penetrating trauma and 15 injuries to blunt force. An overall amputation rate of 16 percent followed attempts at vascular repair. Blunt injuries were associated with a 30 percent amputation rate, whereas penetrating injuries were associated with only a 5 percent amputation rate. When our results were reviewed and compared with those of others, several factors important for determining the rate of limb salvage in popliteal vascular injuries were noted: (1) early recognition and prompt treatment, (2) absence of blunt injury with attendant soft tissue damage; (3) resection of damaged arterial tissue with end-to-end anastomosis or saphenous vein grafting in conjunction with the liberal employment of local heparin and a Fogarty catheter thrombectomy, (4) repair of concomitant popliteal venous injuries; (5) use of completion arteriography to reveal technical errors amenable to correction at time of operation; and (6) fasciotomy, used liberally but selectively.

The hairless mouse as a model for quantitating skin deposition of 3,4,4'-trichlorocarbanilide in bar soap.

A method is described for quantitating the deposition of the germicide 3,4,4'-trichlorocarbanilide (TCC) via direct application of bar soap to the skin. The soap contained 1.5% [14C]TCC. Quantitating the skin deposition of biologically active materials is important in the safety evaluation of these ingredients as well as the finished products. In the case of rinse-off products such as soaps, the residue remaining after rinsing constitutes the major portion of material available for penetration. The hairless mouse and the clipped albino Sprague-Dawley rat were evaluated as models for human skin deposition. Little TCC remained on the skin of either species following the wash and rinse procedure. The amount deposited on rat skin was 1.5% of the applied dose or 0.87 micrograms TCC/cm2 while the amount deposited on hairless mouse skin was 1.1% or 0.18 micrograms TCC/cm2. The greater deposition of TCC onto rat skin was likely to be due to the presence of a greater amount of hair. Results obtained using the hairless mouse were consistent and reproducible. The hairless mouse does not require shaving and is easy to handle. Since, like man, it has little hair, it appears to be an excellent model for use in predicting the deposition of TCC on human skin.

Deposition of 3,4,4'-trichlorocarbanilide on human skin.

For rinse-off products such as soaps, quantitating the deposition of ingredients left behind on the skin following rinsing may be important particularly if the ingredient is biologically active, e.g. germicides, perfumes. The residue comprises the major portion of material which is available for percutaneous penetration. A method is described for quantitating the deposition of the soap germicide, 3,4,4'-trichlorocarbanilide (TCC) as the result of direct application of bar soap on human skin. A soap pellet containing 1.5% [14C]TCC was gently rubbed on a small area of the volar forearm for 30 s. 90 s after soap application the site was thoroughly rinsed with water. After rinsing, 1.4% of the applied [14C]TCC, or 0.33 micrograms/cm2, remained on the treated site as determined by cellophane tape stripping followed by scintillation counting. The amount of TCC deposited from a simulated wash with a bar soap onto human skin is compared to the amount deposited onto the skin of other species.

Evaluation of an in vitro cell toxicity test using rabbit corneal cells to predict the eye irritation potential of surfactants.

Surfactants reported to be severely, moderately or non-irritating to the eyes of albino rabbits were tested for cell toxicity in vitro using an established line of rabbit corneal cells. Test substances at different concentrations were added to culture dishes containing the rabbit corneal cells or were administered at a dose of 0.01 ml directly to the corneal surface of albino rabbits. A significant rank correlation (r = 0.90, P less than 0.01) was seen between the relative toxicity produced in vitro and the relative eye irritation produced in the modified Draize test. The in vitro method offers a means for screening potentially irritating chemicals without using live animals and may be useful in the selection of product formulations for in vivo testing.

Subchronic inhalation studies of complex fragrance mixtures in rats and hamsters.

Users of consumer products are invariably and intentionally exposed to complex mixtures in such products. With finished fragrance products, these mixtures may represent 100 or more fragrance raw materials (FRMs). The objective of the described studies was to evaluate the safety of finished fragrance products via the inhalation route. In total, the finished products contained approximately 100 FRMs at concentrations of 1% or greater. Major FRMs evaluated included benzyl acetate, coumarin, hydroxycitronellal, musk ketone, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-gamma-2-be nzopyran (HHCB) and phenyl ethyl alcohol. Groups of rats or hamsters were exposed by inhalation (whole body) to the mixtures at 5, 9 or 50 mg/m3 for 4 h per day, 5 days per week for 6 or 13 weeks. For each of the fragrance products, the doses used generally represented a ten- to 100-fold exaggeration of levels expected to be achieved during typical use by consumers. With one exception, the fragrances were aerosolized prior to introduction into the inhalation chamber. The exception product was formulated with a propellant, packaged in a pressurized container and expelled with an automated actuator. In all studies, chamber concentrations of fragrance were monitored. Particle sizes ranged from 0.5 to 7.5 microm, depending on the study. Subchronic exposure to all fragrance mixtures resulted in no toxicologically significant effects on animal survival, behavior, body weights or weight gains, organ weights, or in hematology, clinical chemistry, or urinalysis parameters. No gross pathological or histopathological findings related to test material exposures were observed. These studies support the conclusions that the fragrance mixtures would not pose a hazard to product users based on repeated and exaggerated inhalation exposures of animals.

Appendicitis: why so complicated? Analysis of 5755 consecutive appendectomies.

A perceived high rate of complicated (gangrenous or perforated) appendicitis, despite advances in laboratory and radiographic diagnostic modalities, prompted a review of our experience with appendicitis followed by a prospective analysis that examined the time course from presentation to definitive treatment in 218 consecutive patients. In 5755 appendectomies, our overall rate of complicated appendicitis was 32 per cent; higher in males, in the young, and in the elderly; and relatively stable over each year reviewed. Prospectively, we determined that of the various time intervals, the time from the onset of symptoms to first seeking medical attention is the only significant predictor of complicated appendicitis (39.8 vs 16.5 hours for acute appendicitis). On the other hand, the time from surgical evaluation to operative intervention was significantly shorter for complicated appendicitis (3.8 vs 4.7 hours for acute appendicitis). The high rate of complicated appendicitis with its subsequent sequelae of increased morbidity and resource expenditure is primarily the direct result of patient delay in seeking medical attention and not the result of diagnostic dilemma or surgical delay. Public education, specifically targeting those groups at risk, may provide a substantial and significant solution to the complicated appendix.

Prediction of the eye irritation potential of shampoos using the in vitro SIRC cell toxicity test.

Shampoos predicted to vary over a wide range in their potential to cause eye irritancy were tested in SIRC rabbit corneal cells for cytotoxicity. Six shampoos at at least ten different concentrations were added to culture dishes containing the SIRC cells and were administered at a dose of 0.01 ml directly to the corneal surface of the albino rabbit eye. When the shampoos were ranked both according to their relative toxicities in vitro and according to their relative irritancies in the modified Draize test the resulting rank orders were in perfect agreement. The results demonstrate that the SIRC cell line is a suitable model system for screening shampoos of differing surfactant compositions without the need to use live animals. Further, results obtained from the SIRC cell assay should aid in the selection of final product formulations for in vivo testing as part of the pre-market clearance process.

A selected ion monitoring GC/MS assay for 3,4,4'-trichlorocarbanilide and its metabolites in biological fluids.

A selected ion monitoring gas chromatography/mass spectrometric method for the quantitative determination of 3,4,4'-trichlorocarbanilide (TCC) and its major metabolites (the 2'-hydroxy sulfate and the N- and N'-glucuronides) in human plasma and urine was developed using the deuterium-labelled compounds as internal standards. Limits of detection of 3 ng/mL in urine for the N-glucuronides and of 1.5 ng/mL in plasma for the 2'-hydroxy sulfate were attained. Use of the method was illustrated in a study in human subjects employing TCC-containing bar soaps.

A stingray spine in the scapula of a bottlenose dolphin.

A stingray spine was found lodged in the scapula of a deceased 272 cm, male bottlenose dolphin (Tursiops truncatus) from South Carolina (USA) following skeletal preparation, nearly 6 mo after necropsy. No external puncture wound, internal bruising, or laceration of muscle tissue surrounding the scapula was evident during necropsy of the animal. Implantation of the spine did not appear to be related to the death of the dolphin, but probably occurred at an early age. Abnormal development of bone surrounding the spine resulted in the formation of a cavity at the wound site. Two mechanisms were considered as contributors for the cavity formation. These were the mechanical action of the spine stimulating the body's defense system for managing foreign objects, and the release of potent toxins from the spine sheath.