Showing papers in "Southern Medical Journal in 1990"

Morbidly obese patients' perceptions of social discrimination before and after surgery for obesity.

Abstract: Morbidly obese patients' perceptions of obesity-related prejudice and discrimination were assessed before and 14 months after operation for obesity. Preoperatively, the 57 consecutive patients perceived overwhelming prejudice and discrimination at work, within the family, and in public places. After a weight loss of more than 45.5 kg (100 lb), these patients perceived little or no prejudice or discrimination. We examine factors contributing to the change in patients' perceptions and comment upon patients' perceptions of the negative attitudes held by health professionals toward obese patients.

Why doctors have difficulty with sex histories.

Abstract: Studies have shown that physicians' performance has not been as good as it should be in detecting sexually transmitted diseases (STDs) and in counseling patients about their transmission. The AIDS pandemic has underscored the need to find out why this is true. In our study, we identified the major reasons physicians believe other doctors fail to take adequate sex histories. Scales were then developed to measure the three principal reasons given by these physicians: embarrassment, belief that the sex history is not relevant to the patient's chief complaint, and belief by the physicians that they are not adequately trained. When 350 senior medical students were surveyed, 93% thought that knowledge of a patient's sexual practices is an important part of their patient's medical history, but 50% felt poorly trained to take this history and 25% felt embarrassed to ask the necessary questions. To learn why some students score well on these three dimensions and others do not, a limited number of personal attributes were measured and correlated with the scores on these three measures. Shyness and social anxiety as a personal trait predicted which student was most likely to experience embarrassment in taking a sex history. A nonsympathetic view of patients' psychosocial problems was the variable most closely related to the belief that the sex history was of little importance in understanding a patient's problem. Students who believed this most strongly were the same ones who were most homophobic, authoritarian, and had the greatest fear of AIDS infection. The sense of not feeling adequately trained to take a sex history related most strongly to low self-esteem. How these barriers to STD risk assessment might be overcome is discussed.

Trauma in the Elderly: Determinants of Outcome

Abstract: Severity of injury, patient age and preexisting medical conditions, time from injury to treatment, and quality of care rendered are generally recognized as major determinants of outcome after trauma. In a retrospective review, we compared 456 elderly patients (age greater than or equal to 65 years) with traumatic injuries to 985 younger patients (age less than 65). We compared cause of injury, injury severity score (ISS), seven risk factors indicating preexisting disease, complications, length of stay, and mortality. Overall mortality was 6.0% for patients aged less than 65 years and 8.6% for those older than 65. The injury severity score at which the probability of death was 10% was 17.3 in the older group and 24.9 in the younger group. Factors associated with outcome included cause of trauma (P less than .001), ISS (P less than .001), and number of complication factors (P less than .01). Preexisting risk factors were not significantly associated with outcome. We conclude that trauma in the elderly causes higher mortality with less severe injury, and that the mortality is related to the cause and severity of the trauma and the number of complications, and not to pre-existing disease. Length of stay increases with the severity of injury, except in the severely injured, who die.

Verification of sleep apnea using a portable sleep apnea screening device.

Abstract: Sixty-seven patients referred to a sleep laboratory with a tentative diagnosis of obstructive sleep apnea were examined with a device designed for home use as an apnea screening system. Direct comparison was made between data obtained by the portable device and by data acquired simultaneously with standard polysomnographic techniques. The portable recorder measured nasal/oral airflow, chest wall movement, cardiac rhythm, and blood oxygen saturation. There was no significant difference in the number of disordered breathing events (apneas and hypopneas) recorded by the two systems. The portable device was found to have a sensitivity of 95% and a specificity of 96%. Indications and limitations for use of the portable home apnea screening test are reviewed and guidelines for normalcy suggested.

Evaluation of Acute Traumatic Hemarthrosis of The Knee Joint

Abstract: Acute hemarthrosis of the knee usually results from a significant injury. Preoperative assessment, examination under anesthesia, and arthroscopic examination were conducted on patients with a total of 132 acutely injured knees associated with hemarthrosis and minimal clinical laxity to determine the presence and extent of injury to ligamentous and/or intra-articular structures. Partial or complete tear of the anterior cruciate ligament was found in 101 (77%) of the knees. Peripheral meniscal tears were responsible for the hemarthrosis in 17 cases (13%), and osteochondral fractures were found in 11 cases (8%). Injury to the anterior cruciate ligament was frequently associated with concomitant injury to other structures: meniscal tears (61%), ligament/capsular injury (40%), and hyaline chondral damage (16%). Patients' responses to preoperative anterior drawer, pivot shift, and Lachman tests were within normal limits in 18%, 29%, and 73% of cases, respectively. Patients under anesthesia responded to the anterior drawer and pivot shift tests normally 50% and 74% of the time. The Lachman test, performed under anesthesia, was 98% accurate in predicting anterior cruciate injury. Experience gained in evaluating posttraumatic hemarthrosis of the knee suggests clinical examination alone may not demonstrate the severity of many of these injuries. Arthroscopy, although not necessary to determine competence of the anterior cruciate ligament, is invaluable in determining the existence of other injuries with or without an associated anterior cruciate ligament tear.

Fascia lata graft as a dural substitute in neurosurgery.

Abstract: We present 37 cases in which fascia lata was used for dural patching when there was inadequate regional tissue, such as pericranium or temporalis fascia to repair the dural defect. Operative indications included tumor in 17 patients (46%), trauma in nine (25%), cerebrospinal fluid fistula in seven (19%), infection in two (5%), dural patching in two (5%). Follow-up ranged from one month to five years, with an average follow-up of two years. There were no cranial or spinal complications related to the fascia lata grafting (including cerebrospinal fluid leakage, meningitis, and wound infection). Fascia lata is relatively simple to obtain, but harvesting necessitates a second incision; this second incision resulted in no complications in our patients.

Increased infection rate in double-lumen versus single-lumen Hickman catheters in cancer patients.

Abstract: Over the 48-month period from January 1983 through December 1986, 51 single-lumen (SL) and 94 double-lumen (DL) indwelling central venous (Hickman) catheters were placed in 118 patients with malignant disease. We reviewed these cases retrospectively to determine the types and frequency of complications requiring catheter removal. The catheters were in place a total of 18,397 days. Overall, 14% (7/51) of SL and 21% (20/94) of DL catheters were removed due to infection. Of those catheters becoming infected, DL catheters were infected earlier. SL catheters that became infected averaged 213 days of use before removal, whereas DL catheters becoming infected averaged only 78 days before removal (P less than or equal to .02). The infection rate was significantly less in SL (one infection per 1,210 days) than in DL catheters (one infection per 496 days) (P less than or equal to .02). Thus because of its significantly reduced risk of infection, the single-lumen Hickman may be the preferred catheter for long-term venous access in many patients.

Reduced axial bone mineral content in patients taking an oral anticoagulant.

Abstract: Recent literature indicates that the vitamin K cycle plays a role in the calcification process, presumably via its intervention on gamma-carboxylation of the noncollagenous proteins of bone osteocalcin and matrix gamma-carboxyglutamic acid protein. The major clinical evidence of this interference is fetal bone defect caused by oral anticoagulants given to the mother during the first trimester of pregnancy. No bone abnormalities have been reported so far in adults receiving oral anticoagulants. We studied 56 women who had had cardiac valve replacement and who were given acenocoumarol as anticoagulant, and 61 age-matched women who were in the same New York Heart Association functional class but who were not taking anticoagulants. Osteocalcin serum levels were comparable between the two groups; bone density values measured at appendicular bone were significantly lower in patients taking acenocoumarol. No significant correlation was found between duration of treatment and bone density. Significant osteopenia was present in the women being treated with oral anticoagulants.

Neurologic approach to drug-induced movement disorders: a study of 125 patients.

Abstract: Of 125 patients with neuroleptic (dopamine blocking) drug-induced movement disorders who had been referred to a specialized clinic to differentiate the predominant movement disorder, 63% had tardive dyskinesia, 30% had parkinsonism, 24% had dystonia, 7% had akathisia, and 2% had isolated tremor. Two or more movement disorders coexisted in 31 patients (25%). Functional disability was more severe in patients with akathisia than in other patients. Women outnumbered men at a ratio of 4:1, except for tardive dystonia which affected both sexes equally. The average at onset was 56 years (range, 13 to 87); 69 patients (55%) had onset of movement disorder in the sixth decade. While tardive dystonia was distributed relatively evenly in all age groups, almost a third of patients with parkinsonism had it in the eighth decade. Haloperidol was implicated in 47 patients (37%), followed by amitriptyline/perphenazine in 30%, thioridazine in 27%, and chlorpromazine in 20%. Metoclopramide-induced movement disorders were found in 10 (8%). Most patients (101 or 81%) had history of psychiatric illnesses, but of these only 44 had psychosis. Neuroleptic drugs had been prescribed for 33 patients (26%) who had gastrointestinal problems. It is important to recognize and differentiate various drug-induced movement disorders because such differentiation has pathophysiologic and therapeutic implications. Many patients could have been treated with less potent drugs.

Disseminated Histoplasmosis in Patients With AIDS

Abstract: Disseminated histoplasmosis was diagnosed in 36 (4%) of 980 patients with AIDS seen at Parkland Memorial Hospital in Dallas, Texas before September 30, 1989. Diagnostic sensitivity of blood culture plus examination of peripheral smear was 88%; sensitivity of bone marrow aspiration and blood culture was 80%. Median CD4 lymphocyte count at diagnosis was 33/cu mm. Median actuarial survival from the date histoplasmosis was diagnosed was 188 days. Thirteen (36%) of the 36 patients died before adequate antifungal therapy could be administered, while 13 survived long enough to receive 1,500 mg of amphotericin B; actuarial survival of the latter group from the date 1,500 mg of amphotericin B had been infused was 47% at 1 year. The substantial early mortality of AIDS-associated disseminated histoplasmosis and the modestly encouraging survival of those who were diagnosed in time to receive adequate therapy raise the issues of surveillance, prophylaxis, and empiric therapy for this infection in selected HIV-positive patients.

Diabetes mellitus as a risk factor for stroke.

Abstract: To evaluate the relative potency of diabetes mellitus as a risk factor for stroke, the relative frequency of stroke symptoms was compared among cohorts with and without diabetes. Stroke symptoms were classified as atherothrombotic cerebral infarctions, transient ischemic attacks, reversible ischemic neurologic deficits, and multi-infarct dementia. The groups were compared according to the occurrence of these symptoms, and both cross-sectional and longitudinal designs were used to study 293 consecutive patients referred to this laboratory and to contrast groups with and without diabetes. Hypertension, heart disease, and stroke symptoms and signs were more frequent among diabetics than among age-matched nondiabetics. Among diabetics, strokes occurred at an earlier age and were more common among men. Regression analyses assigned diabetes second to hypertension as a risk factor for stroke, followed by heart disease and smoking. Diabetes associated with hypertension or hyperlipidemia added significantly to stroke risk. Initially, cerebral blood flow values and cognitive test scores were equivalent among diabetics and nondiabetics; after 3 years, cognition became significantly impaired among diabetics, despite better maintenance of cerebral blood flow among treated diabetics compared with nondiabetics. Diabetes acts to compound risk for stroke not only by promoting cerebral atherogenesis but also by aggravating other risk factors including hypertension, heart disease, and hyperlipidemia.

Tamoxifen therapy for painful idiopathic gynecomastia.

Abstract: We have evaluated the efficacy of the antiestrogen tamoxifen in six men with painful idiopathic gynecomastia. Subjects were given either tamoxifen or placebo for 2 to 4 months and then were given the other agent for an identical period. Breast size was considered to have been reduced only if it had decreased by one or more Marshall-Tanner stages during the treatment period. Pain reduction with tamoxifen therapy was statistically significant for the group, occurring in five of six subjects during tamoxifen treatment and in only one of six during the placebo period. Size reduction with tamoxifen was only marginally significant for the entire group, but occurred in all three subjects who were initially in Marshall-Tanner stage III and in none of the three subjects who were initially in stage V. During tamoxifen treatment, there was a significant increase in the serum levels of luteinizing hormone and total estradiol and a marginally significant increment in the total testosterone level.

Cardiac loop ECG recording: a new noninvasive diagnostic test in recurrent syncope.

Abstract: The most crucial step in diagnosing syncope is determining whether or not an arrhythmia is the cause. A new recording device, the continuous cardiac loop ECG recorder, affords prolonged ambulatory monitoring and can capture the rhythm at the time of syncope. To determine the impact of cardiac loop ECG recorders in diagnosing syncope, we reviewed the records of the first 48 patients referred for cardiac loop recording because of unexplained syncope or presyncope. Previous cardiac studies were nondiagnostic in all patients. In 36% of these patients, loop recording definitively determined whether an arrhythmia was the cause of symptoms. Median duration of monitoring was 28 days, with an average charge of $180 per month. Cardiac loop ECG recording is a convenient, safe, inexpensive, and potentially highly effective means of diagnosing unexplained syncope.

Nephrotoxicity Associated With Concomitant ACE Inhibitor and NSAID Therapy

Abstract: Angiotensin-I converting enzyme (ACE) inhibitors and nonsteroidal anti-inflammatory drugs (NSAIDs) can be nephrotoxic and may synergistically compromise renal function. A computer-assisted study was done to asses the prevalence of compromised renal function and the clinical importance of this drug interaction. A search of the records of all patients seen in the University of Nebraska Medical Center Internal Medicine Clinic was conducted to identify cases involving renal insufficiency, therapy with ACE inhibitors, or therapy with NSAIDs. Records of cases meeting these criteria were reviewed for clinical correlation and revealed 2278 patients treated with NSAIDs, 328 with ACE inhibitors, and 162 with both. No nephrotoxicity was found in conjunction with monotherapy, but three cases of reversible renal failure were found in conjunction with combination therapy. Significant nephrotoxicity during the concomitant use of ACE inhibitors and NSAIDs is not uncommon, and attention should be drawn to this potentially important interaction.

Efficacy of sedation of children with chloral hydrate.

Abstract: Chloral hydrate has been used extensively to sedate children, but at Brooke Army Medical Center, other drug combinations were becoming increasingly popular due to a perception that chloral hydrate had a high rate of failure, especially with younger or neurologically impaired children. Therefore, 50 children were given the drug before a diagnostic study, and patient data and a sedation score were recorded on a worksheet. Of 50 children, 43 (86%) were "successfully sedated" on the first attempt with no side effects. Children with neurologic disorders had a much greater (27% vs 4%) failure rate than "normal" children. The sedation rate did not significantly differ by age, sex, or initial drug dosage. The study suggest that chloral hydrate is a safe and effective oral sedative but that children with neurologic disorders may need alternative drugs for sedation.

Disseminated strongyloidiasis in AIDS and non-AIDS immunocompromised hosts: diagnosis by sputum and bronchoalveolar lavage.

Abstract: In conclusion, disseminated strongyloidiasis is a fatal disease that commonly affects the lungs. The disease should be suspected in an immunocompromised host who came from an area endemic for S stercoralis even years before the onset of symptoms or in patients with unexplained gram-negative bacteremia or meningitis. Treatment should be started promptly and should be maintained for a long time.

Thallium-201 scintigraphy in the diagnosis and management of myocardial sarcoidosis.

Abstract: We have described three patients with clinical evidence of myocardial sarcoidosis to illustrate the utility of thallium-201 scintigraphy in demonstrating the myocardial lesions. Both the symptomatic and asymptomatic individuals studied showed the characteristic "reverse redistribution" phenomenon. No abnormalities were seen during the exercise phase of the thallium study, but myocardial defects were detected in each patient when repeat studies were obtained at rest six hours later. Steroid therapy resolved the defects in each case. We propose thallium-201 scintigraphy of the heart as a safe and useful tool for documenting myocardial involvement in sarcoidosis and following the effects of therapy.

Sigmoid Volvulus in Childhood

Abstract: Although it is common in the adult population, sigmoid volvulus is unusual in childhood. We report the cases of four children treated for sigmoid volvulus, and we review an additional 44 cases. The mean age of occurrence was 8 years. Predisposing factors were present in 33%. Abdominal pain (66%), vomiting (31%), and obstipation (10%) were the most common symptoms. Abdominal findings included distention (69%), tenderness (41%), and a mass (10%). The classic roentgenographic omega sign of volvulus was present on plain films in only 29% of the cases. Barium enema examination was diagnostic in 61% of the cases in which it was used. Nonoperative treatment by barium enema or proctoscopy was successful in all 17 cases in which it was attempted. The recurrence rate after nonoperative treatment was 31%. Thirty children had operation. The mortality in the group of patients having "derotation" alone was 29%. Immediate resection was associated with a 25% mortality; none of the patients who had elective resection died. Sigmoid resection is the definitive treatment for children as well as adults, but nonoperative decompression to allow for elective resection should be attempted in patients who have no evidence of peritonitis.

Long-term buspirone therapy for chronic anxiety: a multicenter international study to determine safety.

Abstract: This report presents results from an international multicenter trial of the safety of buspirone in the treatment of anxiety disorders for periods up to one year, if needed; 424 patients were treated for six months, and 264 patients completed a full year of treatment. Chronic use of buspirone for up to 52 weeks was associated with emergence of no new or unexpected side effects that were not previously reported during shorter periods of treatment. Most patients were successfully managed on daily doses ranging from 15 to 30 mg/day. When buspirone therapy was abruptly discontinued after more than six months of therapy, assessments of patients yielded no evidence of a withdrawal syndrome or unusual events. Although long-term anxiolytic drug therapy is not generally recommended, this open study provides evidence of the potential usefulness of buspirone when used for up to one year. As a general guideline, when an anxiolytic agent is used for several months or longer to treat chronic anxiety, the need for drug therapy should be reevaluated periodically.

Urachal abnormalities in adults: the Ochsner experience.

Abstract: Urachal abnormalities are very rarely encountered in adults. Though the urachus is normally obliterated in early infancy, it may cause a lower midline lesion in adults. Urachal abnormalities can be classified into five groups: patent urachus, urachal sinus, vesicourachal diverticulum, urachal cyst, and alternating sinus. The medical records of Ochsner Medical Institutions were reviewed for the 31-year period 1957 to 1988. Forty-one patients were identified as having anomalies of the urachus, 11 of them in the adult age group (older than 17 years). All cases were documented by pathologic examination. All patients were treated surgically, with no resultant morbidity or mortality.

Acetaminophen hepatotoxicity in the alcoholic

Abstract: In a retrospective review from 1987 to 1989, we identified seven alcoholics who had severe acute hepatocellular injury soon after using acetaminophen for therapeutic purposes and who had no suicidal intent. All had markedly elevated serum transaminase values (aspartate aminotransferase greater than 4000 U/L) and prolonged prothrombin times. Three died. Use of acetaminophen by the alcoholic patient is potentially lethal.

Percutaneous endoscopic gastrostomy and early mortality.

Abstract: To assess morbidity, mortality, and benefit associated with percutaneous endoscopic gastronomy (PEG), we retrospectively studied 42 patients who had had PEG. Mortality was exceptionally high during the first 60 days after PEG (43%), and then stabilized. In nearly half of the cases (20/42) the PEG tube was removed during the first 60 days because of either death or improvement. Patients with malignancy had a significantly higher morbidity and 60-day mortality than the neurologically impaired. We concluded that patients should be carefully selected for PEG because early mortality is high; a 60-day trial of soft nasogastric feedings should be considered before PEG, and could reduce by nearly half the number of patients failing to receive long-term benefit; and patients with malignancy have significantly greater morbidity and mortality after PEG and may not receive the same advantage from the procedure.

Pancreaticoduodenal artery aneurysms: changing patterns.

Abstract: A true pancreaticoduodenal artery (PDA) aneurysm (ie, one not associated with pancreatitis) is the second least common splanchnic artery aneurysm; it is usually situated in or near an area that is hard to dissect, and it has a distinct propensity to rupture. We reviewed a total of 36 cases of PDA aneurysm, including three from our institution, and we analyzed them in two time periods with relation to age, sex, method of diagnosis, morbidity, and mortality. Cases reported before 1970 were compared with those reported during or after 1970. The male-female ratio was 4:1 before 1970 and 1:1 after 1970, yet the mean age has stayed significantly lower for female populations (P less than .02). The use of angiography has increased significantly recently (P = .004). The overall mortality has not improved significantly (P = .08); however, if the initial diagnosis was made by angiography, the survival was significantly better (P less than .025). Surgical intervention remains the standard treatment, but preoperative angiography significantly improves operative results. Anecdotal reports suggest that selected high-risk cases may be successfully managed by therapeutic angiography with embolization.

Carcinoma of the male breast: a review of 41 cases.

Abstract: :We reviewed the cases of 41 consecutive men treated for breast carcinoma from 1950 through 1987 at Vanderbilt University Affiliated Hospitals to examine controversies in and methods of therapy for this disease. Twenty-two patients (52%) had stage I or II lesions potentially curable by opera

Comparison of cefuroxime axetil, cefaclor, and amoxicillin-clavulanate potassium suspensions in acute otitis media in infants and children.

Abstract: In this randomized, blinded, multicenter comparison study, 377 infants and children with acute otitis media (AOM) received a 10-day course of an oral suspension of one of the following: cefuroxime axetil (CAE), 30 mg/kg/day; cefaclor (CEC), 40 mg/kg/day; or amoxicillin-clavulanate potassium (AMX-CL), 40 mg/kg/day. Clinical efficacy was determined by pneumatic otoscopy and tympanometric testing 3 to 5, 11 to 14, and 22 to 26 days after the initiation of therapy. There was a statistically significant difference among the three treatment groups with respect to clinical outcome; more patients in the CAE group (62%) than in the CEC group (46%) or the AMX-CL group (52%) had complete resolution of signs and symptoms of AOM (including effusion). Paired comparisons revealed a significant difference in efficacy between CAE and CEC and a nearly significant difference between AMX-CL and CEC. Taste acceptability was highest for CEC and lowest for this formulation of CAE. Significantly more patients in the AMX-CL group than in the CAE or CEC group had a side effect, primarily diarrhea, vomiting, or diaper rash. We conclude that CAE suspension has greater clinical efficacy than CEC and fewer side effects than AMX-CL.

Disseminated cutaneous and synovial Mycobacterium marinum infection in a patient with systemic lupus erythematosus.

Abstract: A patient with systemic lupus erythematosus had a protracted skin infection with Mycobacterium marinum after a puffer fish sting. Disseminated cutaneous and synovial disease was associated with clinically active systemic lupus erythematosus two years after the initial infection. The infection was poorly responsive to multiple antituberculous regimens. Hematogenous spread of infection was the likely route of dissemination.

Endocarditis and hip arthritis associated with Scedosporium inflatum.

Abstract: A 30-year-old man had endocarditis and hip arthritis associated with the recently recognized fungus, Scedosporium inflatum. Inhibition, and possibly cure, of endocarditis occurred with medical therapy alone. Data from in vitro susceptibility testing did not predict clinical response. This case also illustrates the need to standardize fungal susceptibility testing and to remain vigilant for emerging pathogens.

Clindamycin/primaquine therapy and secondary prophylaxis against Pneumocystis carinii pneumonia in patients with AIDS.

Abstract: We found a program of intravenous and subsequent oral clindamycin, combined with oral primaquine, to be effective for Pneumocystis carinii pneumonia in nine patients with AIDS. The pneumonias were either primary or recurrent and sometimes severe, with cavity formation and/or pneumothorax. Maintenance therapy at lowered dose by mouth was effective in preventing recurrence in seven patients. One patient died of other opportunistic infections on day 24, and therapy was discontinued in another on day 11 because of skin rash. We conclude that clindamycin/primaquine is effective for therapy of P carinii pneumonia in patients with AIDS, as well as for long-term secondary prophylaxis at lowered dosage.

Skin grafting: dermal components in inhibition of wound contraction.

Abstract: The inhibition of wound contraction by skin grafting is widely accepted but poorly understood. We used an experimental model of contraction to study the effect of dermal organization, cellularity, and collagen matrix on contraction inhibition. Wound beds covered with inverted and collagen matrix grafts contracted at the same rate as full-thickness grafts. Heat denaturation diminished this ability. Partial-thickness grafts derived from papillary or reticular dermis inhibited contraction to an equal degree. Inhibition of contraction appears to relate to the amount of intact dermal collagen matrix transferred, and not to another component of a full-thickness graft.

Desmopressin and indomethacin therapy for nephrogenic diabetes insipidus in patients receiving lithium carbonate.

Abstract: Individuals receiving lithium carbonate commonly have nephrogenic diabetes insipidus. There is no effective and practical treatment for this condition. We have found that large doses of desmopressin (DDAVP) may provide effective therapy without adverse effects. A recent report showed that indomethacin improved nephrogenic diabetes insipidus that had persisted after the lithium therapy was discontinued. We have provided additional evidence that indomethacin may be effective, even when treatment with lithium is continued. We also have shown that indomethacin together with desmopressin can markedly decrease polyuria, though indomethacin must be used with care because it may impair renal function.