Infrared receptors in the facial pits of the Australian python Morelia spilotes.

There is a series of pits in the scales of the rostrum and posterior portion of the lower lips in some pythons and boas. In the Australian python Morelia spilotes, these pits are innervated by the maxillary and mandibular branches of the trigeminal nerve. Structural and neurophysiological evidence indicate that in the pits there are receptors that function as detectors of radiant heat flux.

Apollo 11: exposure of lower animals to lunar material.

Lunar material returned from the first manned landing on the moon was assayed for the presence of replicating agents possibly harmful to life on earth. Ten species of lower animals were exposed to lunar material for 28 days. No pathological effects attributable to contact with lunar material were detected.

The prevalence of urethral catheterization in Maryland nursing homes.

Urinary incontinence is common in the increasing numbers of aged people and is often the precipitating factor for nursing home admission. Recalcitrant incontinence may be managed by urethral catheters. In this study of a random stratified sample of Maryland nursing homes (4259 patients), we found that the daily prevalence of urethral catheter use in Maryland nursing homes was 7.5%. More than 80% of urethral catheter users were women. Among men, we found equal prevalences of urethral and condom catheter use. Previous studies have demonstrated long-term use of urethral catheters to be associated with almost universal bacteriuria of a polymicrobial and dynamic nature. Combining these data suggests that long-term catheter-associated bacteriuria is the most common infection in American health care facilities.

Once-daily irrigation of long-term urethral catheters with normal saline. Lack of benefit.

Urinary incontinence is often managed with a long-term urethral catheter after other methods have failed. Such urethral catheterization is associated with polymicrobial bacteriuria, catheter obstruction, fever, bacteremia, urinary tract stones, and death. Periodic catheter irrigation is a common but untested management procedure intended to prevent catheter obstruction, fevers, and/or bacteremia. To evaluate this technique, we performed a randomized crossover trial comparing ten weeks of once-daily normal saline irrigation with ten weeks of no irrigation in 32 long-term catheterized women. The incidence of catheter obstructions and febrile episodes and the prevalence and species of bacteriuria were similar whether examined as completed crossover patients (N = 23) or as partially completed trials (N = 9). Once-daily irrigation with normal saline of long-term urethral catheters is a time-consuming and costly procedure that is unlikely to have an impact on the morbidity associated with such catheters.

Kinetics of a carbamazepine-ethosuximide interaction.

Carbamazepine and ethosuximide are used together to treat epileptic mixed-seizure patterns. Since carbamazepine has been shown to induce drug-metabolizing enzyme(s) in the liver, it follows that carbamazepine may alter ethosuximide disposition. Six normal subjects took one 250-mg ethosuximide capsule twice each day for 55 consecutive doses (study days 1 to 28) and one 200-mg carbamazepine tablet each evening from study days 11 to 27. Plasma samples were collected on study days 10, 17, 21, and 28. Mean steady-state concentrations of ethosuximide declined by 17% from a preinduction (study day 10) level of 32.2 +/- 5.6 micrograms/ml to a postinduction level of 26.8 +/- 5.2 micrograms/ml on study day 28. Ethosuximide clearance increased (alpha = 0.05) between study days 10 and 28 from 0.664 +/- 0.120 to 0.800 +/- 0.0154 l/hr. The time course of induction was analyzed using a kinetic induction theory. Ethosuximide half-life was lowered from mean - 53.7 +/- 11.5 hr (before induction) to mean = 44.6 +/- 10.7 hr (after induction); the difference between some subjects was large. These data show that ethosuximide disposition is altered by carbamazepine.

Bat-associated histoplasmosis in Maryland bridge workers.

An epidemic of acute prolonged febrile respiratory disease affecting nine of 19 workers on a Maryland State bridge maintenance crew was diagnosed as histoplasmosis by serologic testing in all and by isolation of the organism in one. In our investigation, it was revealed that work on a particular bridge was associated with disease. Culture of bat guano from the site two months later revealed H. capsulatum. Four previously uninfected epidemiologic investigators also became ill with histoplasmosis following collection of soil and bat guano. This outbreak reveals that bats and bat guano are a source of histoplasmosis, suggests that only brief exposure is necessary for acute infection and reemphasizes that histoplasmosis is not confined to the midwestern states.

Identification of best electrocardiographic leads for diagnosing anterior and inferior myocardial infarction by statistical analysis of body surface potential maps.

In view of the increasing interest in quantifying and modifying the size of myocardial infarction (MI), it is important to look for clinically practical subsets of electrocardiographic leads that allow the earliest and most accurate diagnosis of the presence and electrocardiographic type of MI. A practical approach is described, taking advantage of the increased information content of body surface potential maps over standard electrocardiographic techniques for facilitating clinical use of body surface potential maps for such a purpose. Multivariate analysis was performed on 120-lead electrocardiographic data, simultaneously recorded in 236 normal subjects, 114 patients with anterior MI and 144 patients with inferior MI, using as features instantaneous voltages on time-normalized QRS and ST-T waveforms. Leads and features for optimal separation of normal subjects from, respectively, anterior MI and inferior MI patients were selected. Features measured on leads originating from the upper left precordial area, lower midthoracic region and the back correctly identified 97% of anterior MI patients, with a specificity of 95%; in patients with inferior MI, features obtained from leads located in the lower left back, left leg, right subclavicular area, upper dorsal region and lower right chest correctly classified 94% of the group, with specificity kept at 95%. Most features were measured in early and mid-QRS, although very potent discriminators were found in the late portion of the T wave.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheter-associated bacteriuria in long-term care facilities.

Catheter-associated bacteriuria is the most common infection acquired in long-term care facilities. Complications include fever, acute pyelonephritis, bacteremia, catheter obstruction, urinary stones, chronic interstitial nephritis, renal failure, and death. The closed-catheter system has been the only innovation in this traditional method of care that has led to prevention of bacteriuria. Antimicrobial agents rarely are indicated to prevent or treat bacteriuria in long-term catheterized patients, except for those with symptomatic infection. Alternative devices are available and often may be preferable to the indwelling urethral catheter. These patients and their reservoirs of bacteriuric organisms are sources of nosocomial outbreaks. Such outbreaks can be prevented and controlled with attention to catheter hygiene, prevention of patient-to-patient transmission on the hands of caregivers, and possibly use of antimicrobials to diminish bacterial concentrations in the urine.

The use of urethral, condom, and suprapubic catheters in aged nursing home patients.

In this study of 4,259 aged patients in 53 randomly selected nursing homes in Maryland, we found that 10% of women and 15% of men used a urine collection device. Among bedfast patients, 47% of women and 58% of men and, among patients with decubitus ulcers, 37% of women and 33% of men were using a urine collection device. The indwelling urethral catheter was the most commonly used device. Indeed, for women, few other options were available: 93% of women used this device. In women, multiple logistic regression analysis indicated that presence of a decubitus ulcer and occupation of a long-term care bed were the attributes most strongly associated with the use of the urethral catheter. Of men with urine collection devices, 43% were using the urethral catheter; poor mobility status was the characteristic most strongly associated with its use. Long-term urethral catheterization has been well studied and is associated with universal bacteriuria and with a number of complications. Options need to be further explored, particularly external urine collection devices for women. Furthermore, because urethral catheterization may be used as a management technique for decubitus ulcers, prevention of the latter may diminish the use of urethral catheters and their subsequent complications.

Incidence and characteristics of antibiotic use in aged nursing home patients.

OBJECTIVE: To measure the prevalence, incidence, types, and certain characteristics of antibiotics prescribed in nursing homes. DESIGN AND SETTING: Periodic survey over 1 year of patient charts in 53 stratified, randomly selected nursing homes in the state of Maryland. PATIENTS: All patients 65 years of age or more residing in these nursing homes on the first day of study. RESULTS: Of 4,165 patients in 53 nursing homes, records over the year were satisfactory in 3,899 patients in 52 nursing homes. The prevalence of antibiotic use on the first day of the study was 8%. Over the next 12 months, observations of more than one million patient-days revealed an incidence of 0.46 antibiotic courses/100 patient-days; 54% of the 3,899 patients received at least one antibiotic course. For presumed active infections, beta lactam antibiotics were the most commonly used, 54% of antibiotic orders. For all antibiotics, urinary tract infection was the most common indication, eliciting 36% of orders including 9% for asymptomatic bacteriuria. Skin, lower respiratory, and upper respiratory infections comprised 14%-17% each. Physicians prescribed 94% of courses but documented examinations of only 44% of patients at the outset of these courses. Consensus criteria for minimal diagnostic evaluation of four selected infections were met in only 11% of episodes of infection. Although the most serious infections tended to be better evaluated than others, 31% of the former were not noted to have been examined by a physician. Three percent of orders were for prophylaxis and two-thirds of these antibiotics were administered for more than 2 days. CONCLUSIONS: Antibiotics are frequently prescribed for aged nursing home patients, often in the absence of a physician's examination and other features commonly performed in evaluation of specific infectious diseases. More than one-fifth of antibiotics prescribed by presumed active infections were for two infections usually thought not to require antibiotic therapy, "viral" upper respiratory infection (13%) and asymptomatic bacteriuria (9%). To optimize antibiotic use in nursing homes, greater attention should be directed to appropriate durations of prophylaxis for urologic, dental, and minor surgical procedures; to standards for diagnostic evaluations of common infections; and to the roles of antibiotics in upper respiratory infections and in asymptomatic bacteriuria.

Proxies' decisions about clinical research participation for their charges.

OBJECTIVE: To examine the process by which proxies decide about their charges' participation in clinical research. DESIGN: Using eight hypothetical research studies encompassing a variety of risks and benefits, we interviewed 315 competent persons > or = 65 years old (charges) and, separately, the individuals who would be designated as their proxies if the charges were to become incompetent. The proxies were asked what they thought their charges would decide and what decisions they would make for their charges and for their own participation. SETTINGS: A medical house-call program, two apartment complexes, and three nursing homes. PARTICIPANTS: Charges > or = 65 years old and their proxies. MAIN OUTCOME MEASURE: Comparison of decisions made by charges and by proxies for their charges. RESULTS: The agreement between the proxies' and charges' decisions was not significantly different from random agreement (range of kappa statistics, 0.05-0.15). Rather, proxies' decisions for their charges were significantly related to the proxies' decisions for themselves (kappas, 0.52-0.86). When the paired proxies' and charges' decisions differed, the proxies were protective, more frequently refusing their charges' participation in the perceived riskier research studies. CONCLUSIONS: Proxies did not know what their charges would decide. Their choices for the charges related more to the proxies' decisions about their own participation (which they knew) than to the decisions of their charges (which they didn't know). This is similar to the process of a reasonable person making the decision, a characteristic of decisions made in the best interests of the patient.

Long-term urethral catheterization increases risk of chronic pyelonephritis and renal inflammation.

OBJECTIVE: To determine the prevalences of chronic pyelonephritis and chronic renal inflammation in elderly nursing home patients at the time of death and to assess correlation with urethral catheterization and other putative risk factors. DESIGN: Prospective assessment of risk factors with the prevalences of chronic pyelonephritis and renal inflammation at autopsy. SETTING: A 240-bed long-term care facility. PARTICIPANTS: All residents > or = 65 years old who died and were autopsied during a 2-year period. MEASUREMENTS: Antemortem assessment of risk factors for renal inflammation, including a search for any urethral catheterization in the person's life. Prospective assessment of urethral catheterization, catheter obstruction, and use of anti-inflammatory medications and urine cultures. Urinary tract pathology was assessed for gross and microscopic evidence of inflammation and urinary tract stones. RESULTS: The duration of catheterization was significantly associated with increasing prevalence of bacteriuria, polymicrobial bacteriuria, chronic pyelonephritis, and chronic renal inflammation. The prevalence of chronic pyelonephritis at death was 10 percent (5/52) for patients catheterized > 90 days during their last year of life and zero (0/65) when catheterized < or = 90 days (P < 0.02; Fisher's exact test). Chronic pyelonephritis was significantly associated with renal stones and hydronephrosis. The prevalence of chronic renal inflammation without chronic pyelonephritis was significantly greater than that of chronic pyelonephritis: the prevalence was 43 percent (20/47) when catheterized > 90 days and 18 percent (12/65) when < or = 90 days (P < 0.05). Chronic renal inflammation was associated with hydronephrosis, ureteral dilatation, acute pyelonephritis and diastolic hypertension. CONCLUSION: Chronic pyelonephritis and chronic renal inflammation are associated with long-term catheterization.

A practical method of estimating stature of bedridden female nursing home patients.

Accurate measurement of stature is important for the determination of several nutritional indices as well as body surface area (BSA) for the normalization of creatinine clearances. Direct standing measurement of stature of bedridden elderly nursing home patients is impossible, and stature as recorded in the chart may not be valid. An accurate stature obtained by summing five segmental measurements was compared to the stature recorded in the patient's chart and calculated estimates of stature from measurement of a long bone (humerus, tibia, knee height). Estimation of stature from measurement of knee height was highly correlated (r = 0.93) to the segmental measurement of stature while estimates from other long-bone measurements were less highly correlated (r = 0.71 to 0.81). Recorded chart stature was poorly correlated (r = 0.37). Measurement of knee height provides a simple, quick, and accurate means of estimating stature for bedridden females in nursing homes.

Commonly used methods of estimating creatinine clearance are inadequate for elderly debilitated nursing home patients.

We evaluated the Jelliffe and the Cockcroft and Gault methods of estimating creatinine clearance in elderly nursing home patients (65 years) with chronic indwelling urethral catheters. Although these relationships have been prospectively validated in hospitalized and ambulatory populations previously, we found that they produced poor estimates of creatinine clearance in this patient group. For the Jelliffe method, 11 of 19 estimates were 20% or greater from the measured value; 10 of 11 poor estimates were high. The Cockcroft-Gault method had 10 of 19 estimates 20% or greater from the measured value with 8 of 10 of the poor estimates being high. An altered relationship between body weight, muscle mass, and daily creatinine production is the most likely explanation for the bias in these creatinine-clearance estimations. New estimates of the relationships between age, weight, serum creatinine, and creatinine clearance need to be developed for this population.

Recruitment of long-term care facilities for research.

We report the successful recruitment of a stratified random sample of nursing homes in the state of Maryland into three research studies funded by the National Institute on Aging. These studies examine the prevalence of infections and urinary tract instrumentation and the incidence of antimicrobial use in nursing home residents. Following selection of a facility, the administrator was telephoned and a meeting at the home was requested. At this meeting, the project was explained in detail using a packet of promotional information which included a project summary, a listing of project staff and their qualifications, and letters of support from influential organizations. A total of 61 eligible facilities were contacted in order to achieve a group of 53 participating homes with approximately 5000 beds. One hundred percent cooperation was achieved from all strata except small (less than or equal to 50 beds) proprietary comprehensive care facilities, and homes with both comprehensive and domiciliary beds. A direct, personal approach, backed by a carefully prepared study information and the support of medical and nursing home organizations resulted in successful recruitment of 53 (87%) of 61 homes sampled.

An external urine collection device for incontinent women. Evaluation of long-term use.

Urinary incontinence is common in aged women, may precipitate nursing home admission, and may prompt use of a urine collection device, usually an indwelling urethral catheter. The safety and efficacy of a new external urine collection device for women that is affixed to the perineum by an adhesive developed for ostomy bags was evaluated. Applied to 26 aged women, 78% of 2,264 devices were leak-free for 24 hours and 49% for 48 hours. The incidence of new bacteriuria was less than half that found in our earlier studies of long-term urethral catheters in the same institution. Perineal erythema was infrequent and preexisting decubitus ulcers improved or did not change. Four patients were withdrawn, one each because of periurethral itching, diminished urine output, recurrent wetness, and fracture of the proximal femur associated with severe osteoporosis. This device may offer an alternative to urethral catheters for management of urinary incontinence but should not be used on women with urine retention and should be used with care on women with severe osteoporosis. Controlled trials must determine effects upon bacteriologic complications and health-care costs.

Prevalence and characteristics of nursing home-acquired infections in the aged.

OBJECTIVES: This study provides estimates of the prevalence of infections in all patients from a representative sample of 53 Maryland nursing homes; identifies risk factors for these infections; and describes diagnostic procedures carried out. METHODS: The records of 4,259 patients in a stratified random sample of 53 Maryland nursing homes were reviewed for diagnostic procedures, medical, functional, and behavioral status. Infections were identified by signs, symptoms, and laboratory findings. RESULTS: Study patients were characteristic of aged patients in US nursing homes. The prevalence of infections actually acquired in the nursing home (80% of all infections) was 4.4%. Multivariate analysis revealed that skin infections (35% of nursing home-acquired infections) were associated with skin ulcers and inversely with urine incontinence. Fevers of uncertain source (13%) were associated with bladder catheters. Symptomatic urinary infections (12%) and lower respiratory infections (12%) were associated with bedfast status, and the latter with tracheostomy and lung disease. Skin ulcers, urethral catheters, and bedfast status were markers for nursing home-acquired infection. The prevalence of infection in patients with all three markers was 32%; in patients with none, 2%. Fewer than a quarter of the four most common nursing home-acquired infections received an evaluation which met minimal diagnostic criteria established by a panel of infectious disease specialists and geriatricians. Patients with dementia, those in large homes (greater than 150 beds), and those in urban homes were less likely to be evaluated in a manner meeting these criteria. CONCLUSIONS: Use of three characteristics (ie skin ulcers, urethral catheters, bedfast status) to identify patients at risk for nursing home-acquired infections may allow targeted infection surveillance and prevention programs. In addition, nursing home-acquired infections are not evaluated uniformly across patients and facilities, suggesting the need to establish, through further study, guidelines for such evaluations.

Lack of interference with creatinine assays by four cephalosporin-like antibiotics.

Some cephalosporin-like antibiotics have been shown to interfere with creatinine assays performed by the commonly used Jaffe methods. The authors show that four new drugs of this type--moxalactam, cefoperazone, cefotaxime, and ceftazidime--do not interfere with this test. A table is presented summarizing all literature data regarding interference with creatinine assays of cephalosporin-like drugs.

Catheter-associated urinary tract infections.

The two most common indications for long-term catheterization are recalcitrant urinary incontinence and urinary obstruction that is not corrected by surgery. For incontinent patients, if behavioral changes, nursing care, special clothes, special bed clothes, and medications have not been successful, then a device to collect urine must be considered. For men such a device is a condom catheter; for women an analogous external collection device would be very useful. Suprapubic catheterization may offer an alternative but has been inadequately studied in this patient population. Long-term urinary catheterization has salutary effects for selected patients including patient comfort, family satisfaction, and nursing efficiency and effectiveness. To the patient for whom any physical movement is uncomfortable or painful, and indwelling catheter may be preferable to frequent changes of clothes. Similarly, the family of of severely impaired patients may want to accept the risks of urethral catheterization in order to keep the patient dry. Further, to the extent that the indwelling catheter is effective in decubitus ulcer prevention and/or management, long-term catheterization may diminish the risk of bacteremia or death from soft tissue infection. These benefits of long-term urethral catheterization, in addition to its risks, should be examined in future studies. Once a urethral catheter is in place, even with good catheter hygiene, bacterial entry can be postponed only temporarily; eventually all patients become bacteriuric. Indeed, as the catheter remains in place, organisms continue to enter, others leave or die, and the bacteriuria becomes complex, polymicrobial, and dynamic. Some organisms, particularly recognized uropathogens such as E. coli and K. pneumoniae, appear to reside in the urinary tract itself. Others, such as P. mirabilis, P. stuartii, and M. morganii, probably establish a niche within the urinary catheter, thus increasing their ability to cause subsequent bladder bacteriuria. The complications of long-term urinary catheterization include fevers, acute pyelonephritis, and bacteremias (such as seen in short-term catheterized patients), as well as catheter obstructions, urinary stones, chronic renal inflammation, local periurinary infections, vasicoureteral reflux, renal failure, and, for very long-term catheterized patients, bladder cancer. The thrust of catheter care for the long-term catheterized patient is to prevent complications of the omnipresent bacteriuria. Unfortunately, clinical opportunities for preventing complications are limited.(ABSTRACT TRUNCATED AT 400 WORDS)

Catheter-associated urinary tract infections.

Millions of urethral catheters are used each year. This device subverts several host defenses to allow bacterial entry at the rate of 3% to 10% incidence per day, and its presence encourages the organism's persistent residence in the urinary tract. Most catheter-associated bacteriurias are asymptomatic. The complications in short-term catheterized patients include fever, acute pyelonephritis, bacteremia, and death; patients with long-term catheters in place are at risk for these complications and catheter obstruction, urinary tract stones, local periurinary infections, chronic renal inflammation, chronic pyelonephritis, and, over years, bladder cancer. The closed catheter system has been a magnificant step forward in the prevention of catheter-associated bacteriuria. Indeed, only two catheter principles are universally recommended: keep the closed catheter system closed and remove the catheter as soon as possible. Most modifications of the closed catheter system have not improved markedly on its ability to postpone bacteriuria. On first inspection, systemic antibiotics seem to be an exception to this rule, but their use results in infection of the bladder with resistant organisms, including candida. This and the effect of side effects on the patient and emergence of resistant bacteria in the medical unit have led most authorities to conclude that antibiotics are not useful for prevention of bacteriuria, nor for treatment of bacteriuria in the asymptomatic catheterized patient. For symptomatic patients, usually with fever or signs of sepsis, treatment of bacteriuria with appropriate systemic antibiotics and removal or replacement of the urethral catheter are indicated. Gloves, hand washing, and segregation of catheterized patients can minimize nosocomial clusters. Because clinicians can only postpone bacteriuria, and once it occurs, clinicians seem unable to prevent its complications, methodologies other than urethral catheters should be used for urine drainage assistance whenever possible. These options include condom, intermittent, suprapubic, and intraurethral catheterization for appropriate patients. The few data available suggest that each one of these catheterization options yields a lower incidence of bacteriuria-and its consequent complications-than urethral catheterization.