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Dietary recalls and urine assays provide different metrics for assessing sodium and potassium intakes. Means, variances, and correlations of data obtained from these two modes of measurement differ. Pooling of these data is not straightforward, and results from studies employing the different modes may not be comparable. To explore differences between these metrics, the authors used data from the Trial of Nonpharmacologic Intervention in the Elderly (TONE), which included repeated standardized 24-hour dietary recalls and 24-hour urine collections administered over 3 years of follow-up, to estimate sodium and potassium intakes. The authors examined data from 341 control participants assigned to usual care that were collected between August 1992 and December 1995. Dietary recalls yielded estimates of sodium intake that averaged 22% less than those from urine assays and estimates of potassium intake that averaged 16% greater than those from urine assays. Sodium intake estimates were less repeatable (r = 0.22 for diet; r = 0.30 for urine) than potassium intake estimates (r = 0.49 for diet; r = 0.50 for urine), making relations with outcomes more difficult to characterize. Overall, the performance of the two measurement modes was fairly similar across demographic subgroups. Errors in separate estimations of long term sodium and potassium intakes using short term data were strongly correlated, more strongly than the underlying long term intakes of these electrolytes. Because of the correlated measurement error, estimated regression coefficients for linear models including both electrolytes as predictors may be confounded such that the separate relations between these nutrients and outcomes such as blood pressure cannot be reliably estimated by common analytical strategies.

Villous tumors of the duodenum are rare tumors which have been infrequently reported in the literature. Surgical treatment options include wide local excision and radical pancreaticoduodenectomy. A case of duodenal villous adenoma presenting with bilious vomiting is presented here.

Background: Strategies to meet sex partners have been augmented by the Internet. This medium is an environment of potential risk for acquiring or transmitting sexually transmitted disease (STD)., Goal: To document how the Internet is used to find sex partners and what risks such activity poses for STD infection., Study Design: Participant observations of 175 chat rooms targeting men who have sex with men (MSM), heterosexuals, and couples seeking sex partners., Results: Findings indicate evidence of past meetings (9% of MSM-room observations, 15% of couple-room observations) and solicitation of sex (9% of heterosexual-room observations, 17% of MSM-room observations, 36% of couple-room observations) by members of these groups. Safer sex or risk-reduction behaviors were not frequently mentioned, but were sometimes acknowledged through solicitation of drug-free and disease-free partners., Conclusions: Because people can use the Internet to solicit sex partners, it is a risk environment for sexually transmitted diseases. The Internet offers fast and efficient encounters resulting in sexual contact, which may translate into more efficient disease transmission. However, the Internet also offers many possibilities for innovative technologic approaches to promote STD and HIV prevention.

Context: Transmission of sexually transmitted diseases (STDs) such as human immunodeficiency virus (HIV) infection is associated with unprotected sex among multiple anonymous sex partners. The role of the Internet in risk of STDs is not known., Objective: To compare risk of STD transmission for persons who seek sex partners on the Internet with risk for persons not seeking sex partners on the Internet., Design: Cross-sectional survey conducted September 1999 through April 2000., Setting and Participants: A total of 856 clients of the Denver Public Health HIV Counseling and Testing Site in Colorado., Main Outcome Measures: Self-report of logging on to the Internet with the intention of finding sex partners; having sex with partners who were originally contacted via the Internet; number of such partners and use of condoms with them; and time since last sexual contact with Internet partners, linked to HIV risk assessment and test records., Results: Of the 856 clients, most were white (77. 8%), men (69.2%), heterosexual (65.3%), and aged 20 to 50 years (84. 1%). Of those, 135 (15.8%) had sought sex partners on the Internet, and 88 (65.2%) of these reported having sex with a partner initially met via the Internet. Of those with Internet partners, 34 (38.7%) had 4 or more such partners, with 62 (71.2%) of contacts occurring within 6 months prior to the client's HIV test. Internet sex seekers were more likely to be men (P<.001) and homosexual (P<.001) than those not seeking sex via the Internet. Internet sex seekers reported more previous STDs (P =.02); more partners (P<.001); more anal sex (P<.001); and more sexual exposure to men (P<.001), men who have sex with men (P<.001), and partners known to be HIV positive (P<.001) than those not seeking sex via the Internet., Conclusions: Seeking sex partners via the Internet was a relatively common practice in this sample of persons seeking HIV testing and counseling (representative of neither Denver nor the overall US population). Clients who seek sex using the Internet appear to be at greater risk for STDs than clients who do not seek sex on the Internet. JAMA. 2000;284:443-446

The objective of this study was to determine whether analgesia-sedation improved patient acceptance of day-case herniorrhaphy and to evaluate the extent of patient morbidity. A total of 98 patients (mean age 34 years, range 17-75 years) were studied before and after herniorrhaphy to determine their response to the procedure. All patients were unpremedicated and underwent herniorrhaphy using a Bassini repair technique with a standard local anaesthetic block. Sedation was obtained with titrated intravenous midazolam(Hypnovel, Roche Products Ltd.) without narcotic analgesia. Patients were evaluated with a simple questionnaire after surgery. The maximum dose of midazolam used was 5 mg (median dose 3.5 mg). Monitoring of vital signs with pulse oximetry during the operative period was routine though oxygen therapy was not required. All patients were able to walk without assistance and were discharged under responsible supervision. Operative morbidity was low (5%). Adverse reactions to the procedure such as nausea, vomiting and headache were not seen. In conclusion, conscious sedation allows amnesia to be achieved with low morbidity in the majority of patients undergoing local anaesthetic procedures. This should result in increased patient acceptance.

Massive ascites is an unusual association with endometriosis. This case report is of such a condition in an Afro-Jamaican woman. The diagnosis was made at laparotomy and conservative treatment was adopted allowing for retention of reproductive function. Postoperative therapy was Goserelin, a Gonadotropin Releasing Hormone (GnRH) agonist, for six months. This relieved all of her symptoms. However, long term follow-up is needed, as recurrence is possible.

Background and Objectives: Although partner notification has been a long-standing intervention and prevention strategy for sexually transmitted diseases (STD), variations in partner notification practices across sites have never been documented., Goals of the Study: To describe provider-assisted partner notification practices in four STD programs in the United States., Study Design: Eleven disease intervention specialists (DIS) in each of three urban sites and seven DIS in one rural site documented their activities and clients for 14 working days using a personal digital assistant., Results: Of 2,506 recorded activity hours across sites, 37.4% of the recorded time was spent on partner notification (PN) activities with 1148 clients. Field visits to locate contacts accounted for the largest proportion of time spent on PN. Overall, PN clients were cases of or were contacts to nonprimary and secondary (P&S) syphilis (39.6%), gonorrhea (25.5%), chlamydia (18.0%), HIV/AIDS (10.4%), and P&S syphilis (6.5%)., Conclusion: The activities which constitute PN, the diseases for which PN is used, and the time spent on each PN client vary across sites. More research is needed on the determinants of these variations and their association with the ultimate goal of disease prevention.

Effect of nickel ions (Ni2+) on noninactivating calcium channels in squid giant fiber lobe (GFL) neurons were investigated with whole cell voltage clamp. Three different effects of Ni2+ were observed to be associated with distinct Ca2+ channel activation states. 1) Nickel ions appear to stabilize closed channel states and, as a result, slow activation kinetics. 2) Nickel ions block open channels with little voltage dependence over a wide range of potentials. 3) Block of open channels by Ni2+ becomes more effective during an extended strong depolarization, and this effect is voltage dependent. Recovery from this additional inhibition occurs at intermediate voltages, consistent with the presence of two distinct types of Ni2+ block that we propose correspond to two previously identified open states of the calcium channel. These results, taken together with earlier evidence of state-dependent block by omega-agatoxin IVA, suggest that Ni2+ generates these unique effects in part by interacting differently with the external surface of the GFL calcium channel complex in ways that depend on channel activation state.

The herpes simplex virus type 1 (HSV-1) mutant in1814 encodes an altered form of the virion protein VP16 that is unable to transactivate immediate-early (IE) transcription. As a consequence of the mutation, in1814 initiates productive replication inefficiently after infection of tissue culture cells. Previous studies showed that this defect could be overcome by the inclusion in the culture medium of hexamethylene bisacetamide (HMBA), a compound that promotes the differentiation of murine erythroleukemia cells (MELCs). The effects of additional agents known to induce differentiation of MELCs were investigated. N'-Methylnicotinamide, at concentrations optimal for the induction of MELCs, complemented the replication of in1814 and stimulated IE gene expression. Suberoyl bishydroxamic acid and suberoylanilide hydroxamic acid, which induce differentiation of MELCs at micromolar concentrations, did not complement in1814 but specifically blocked the action of HMBA. The histone deacetylase inhibitor trichostatin A, which also induces differentiation of MELCs, antagonized the effect of HMBA in a manner similar to that of suberoyl bishydroxamic acid and suberoylanilide hydroxamic acid. The results demonstrate that the requirement for VP16 activity is dependent on the metabolic state of the host cell and that the pathways leading to complementation of in1814 and differentiation of MELCs are overlapping but not identical., (Copyright 1998 Academic Press.)

Adult Still's disease (ASD) is an uncommon form of polyarthritis associated with numerous systemic manifestations, including hepatic involvement. Rarely, liver involvement can be fatal. We describe the case of a young man with ASD with terminal liver failure who required a life saving liver transplant.

Whole cell patch-clamp recordings of Na current (I(Na)) were made under identical experimental conditions from isolated neurons from cephalopod (Loligo, Octopus) and gastropod (Aplysia, Pleurobranchaea, Doriopsilla) species to compare properties of activation gating. Voltage dependence of peak Na conductance (gNa) is very similar in all cases, but activation kinetics in the gastropod neurons studied are markedly slower. Kinetic differences are very pronounced only over the voltage range spanned by the gNa-voltage relation. At positive and negative extremes of voltage, activation and deactivation kinetics of I(Na) are practically indistinguishable in all species studied. Voltage-dependent rate constants underlying activation of the slow type of Na channel found in gastropods thus appear to be much more voltage dependent than are the equivalent rates in the universally fast type of channel that predominates in cephalopods. Voltage dependence of inactivation kinetics shows a similar pattern and is representative of activation kinetics for the two types of Na channels. Neurons with fast Na channels can thus make much more rapid adjustments in the number of open Na channels at physiologically relevant voltages than would be possible with only slow Na channels. This capability appears to be an adaptation that is highly evolved in cephalopods, which are well known for their high-speed swimming behaviors. Similarities in slow and fast Na channel subtypes in molluscan and mammalian neurons are discussed.

Properties of squid giant fiber lobe (GFL) Ca2+ channel deactivation (closing) were studied using whole-cell voltage clamp. Tail currents displayed biexponential decay, and fast and slow components of these tails exhibited similar external Ca(2+)- and voltage-dependence. Both components also shared similar inactivation properties. Increasing duration pulses to strongly depolarizing potentials caused a substantial slowing of the rate of deactivation for the fast component, and also led to an apparent conversion of fast tail currents to slow without an increase in total tail amplitude. A five-state kinetic model that computed the closing of channels differentially populating two open states could simulate the kinetic characteristics of GFL Ca2+ pulse and tail currents over a wide voltage range. The kinetics of the proposed state transition was very similar to the time course of relief of omega-Agatoxin IVA Ca2+ channel block with long pulses. A similar model predicted that the relief of block could occur via faster toxin dissociation from the second open state. Thus, GFL Ca2+ channels possess a unique form of voltage-dependent gating modification, in which maintained prior depolarization leads to a significant delay to channel closure at negative potentials. At the nerve terminal, amplified Ca2+ signals generated by such a mechanism might alter synaptic responses to repetitive stimulation.

Objective: To compare the impact of two different ultrasound methods for assessing amniotic fluid volume on the incidence of obstetric interventions in post-term pregnancies., Design: A prospective randomised controlled trial., Setting: Liverpool Women's Hospital., Participants: Five hundred women with singleton, uncomplicated pregnancies with gestational age > or = 290 days., Interventions: Random allocation to fetal monitoring by either: 1. amniotic fluid index and computerised cardiotocography, or 2. maximum pool depth and computerised cardiotocography., Main Outcome Measures: Primary: caesarean section. Secondary: the number of abnormal monitoring tests, induction of labour, intrapartum management and neonatal outcome., Results: The number of abnormal amniotic fluid indices was significantly higher than the number of abnormal maximum pool depths (10% vs 2.4%; OR 4.51, 95% CI 1.82-11.21; P = 0.0008) which resulted in more inductions for abnormal post-term monitoring in the amniotic fluid index group (14.8% vs 8.4%; OR 1.89; 95% CI 1.07-3.33; P = 0.0362) and more intrapartum electronic fetal monitoring (94.4% vs 88.4%; OR 2.21; 95% CI 1.13-4.29; P = 0.0255). There were no other statistically significant differences in outcomes related to labour and delivery, but there was a trend towards more caesarean sections in the amniotic fluid index group (18.8% vs 13.2%), in particular caesarean sections for fetal distress (8% vs 4%). There were no perinatal deaths and no statistically significant differences in perinatal outcome between the two groups., Conclusions: Published reference ranges for amniotic fluid index overestimate the number of abnormal results in post-term pregnancies. Their use, when compared with maximum pool depth, is likely to increase the number of obstetric interventions with, as yet, an uncertain impact on perinatal mortality and morbidity. It is possible that antepartum fetal assessment in pregnancies where the risk of adverse perinatal outcome is very low may cause, rather than prevent morbidity.

Objectives: This paper describes the financial performance (defined as percent of total expenses covered by net operating revenue) of 16 adult day centers participating in a national demonstration program on day services for people with dementia, including examination of possible predictors of financial performance., Methods: Participating sites submitted quarterly financial and utilization reports to the National Program Office. Descriptive statistics summarize the factors believed to influence financial performance., Results: Sites averaged meeting 35% of expenses from self-pay and 29% from government (mainly Medicaid) revenue, totaling 64% of all (cash plus in-kind) expenses met by operating revenue. Examination of center characteristics suggests that factors related to meeting consumer needs, such as being open a full day (i.e., 7:30 am to 6:00 pm) rather than shorter hours, and providing transportation, may be related to improved utilization and, thus, improved financial performance. Higher fees were not related to lower enrollment, census, or revenue., Conclusions: Adult day centers are able to achieve financial viability through a combination of operating (i.e., fee-for-service) and non-operating revenue. Operating revenue is enhanced by placing emphasis on consumer responsiveness, such as being open a full day. Because higher fees were not related to lower utilization, centers should set fees to reflect actual costs. The figure of 64% of expenses met by operating revenue is conservative inasmuch as sites included in-kind revenue as expenses in their budgeting calculations, and percent of cash expenses met by operating revenue would be higher (approximately 75% for this group of centers).

A consecutive series of 14 patients with anterior abdominal stab wounds and omental evisceration treated at the Kingston Public Hospital Jamaica over a 3-year period is presented. During this period 223 patients with abdominal stab wounds were seen of which 66 had omental evisceration. Conservative surgical management was the approach followed in 14 patients who presented without signs of peritonitis. There were no late complications or missed visceral injuries necessitating laparotomy. Serial physical examination was the method used to select patients for conservative surgical management with the exclusion of patients with deteriorating clinical signs or peritonitis. Omental evisceration through an abdominal stab wound in a patient with stable clinical signs and without evidence of peritonitis is not an absolute indication for exploratory laparotomy.

A unique transgenic mouse line has undergone transgene integration in a very precise fashion. The phenotype displayed by mice of the line followed the predicted inheritance patterns for X-linked transgene insertion which has been confirmed. In order to investigate the mechanism of integration the DNA sequence of the transgene and cellular junctions have been determined. A comparison between wild type and transgenic mutant sequences at the site of insertion revealed that there was no loss or rearrangement of cellular DNA upon integration of the transgene. The cellular sequences at the transgene 5' and 3' joins are contiguous in the wild type. The integrant exists as a head to tail tandem dimer with minimal loss of sequence compared with the injected monomer. Analysis of the site of insertion has revealed a 5 bp homology between the 5' end of the transgene and the cellular sequences. In addition, adjacent to the site of insertion within the cellular sequences, there are several sequence motifs implicated in recombination events including a clustering of strong consensus sites of DNA topoisomerase type I and a region of homology to the human minisatellite consensus core sequence, the Escherichia coli Chi site and the meiotic recombination hotspot within the E beta gene of the murine major histocompatibility complex. This clustering of features is likely to have been factorial in the integrity of the insertion event. A model depicting the mechanism of this precise integration is proposed.

One hundred and twelve patients with penetrating abdominal injuries seen at the Kingston Public Hospital, Jamaica, over a twelve month period from January 1 to December 31, 1992 were reviewed. Seventy-five (67%) patients had stab wounds and thirty-seven (33%) sustained gunshot wounds. There were 10 deaths (27%) from gunshot wounds, and seven deaths (9%) due to stab wounds. Using a protocol of selective conservatism for stab wounds, 41 (60%) were observed, 27 (40%) explored and 5 (12%) patients had negative laparotomy. The male to female ratio was 10:1 with 88% in the age group 16-35 years. A decision to perform laparotomy was based entirely on clinical diagnosis of peritonitis. In gunshot wounds a policy of mandatory laparotomy was used and is recommended.

Background: Arterial blood gas (ABG) values and the alveolar-arterial oxygen (A-a) gradient are sensitive indicators of pulmonary pathology. Alone, they are not diagnostic of pulmonary embolism (PE), but they may be useful in excluding the diagnosis of PE if their values fall within the normal range. The purpose of this study was to determine the diagnostic value of a normal A-a gradient in ruling out PE., Patients and Methods: The Derivation Set came from the records of all patients at Cleveland MetroHealth Medical Center who received a ventilation/perfusion (V/Q) scan for suspected PE in 1988 or 1989. Demographic and clinical data were obtained that included risk factors, symptoms, signs, and laboratory tests. A-a gradients were calculated using a standard equation; a normal gradient was defined as less than or equal to (age/4 + 4). The A-a gradient was examined before and after controlling for PE risk factors. The Validation Set was comprised of patients who had V/Q scans in 1987 and 1990., Results: Among the 873 patients in the Derivation Set, 540 had simultaneous room air ABG determinations. Of these patients, 109 (20%) had a discharge diagnosis of PE. Only 1 of 57 (1.8%; 95% confidence interval [CI]: 0.9%-10.7%) patients without a history of PE or deep venous thrombosis (DVT) and with a normal A-a gradient had PE. Among the 805 V/Q patients in the Validation Set, 489 had simultaneous room air/ABG determinations. Of these, 75 (15%) had PE. Only 1 of 54 (1.9%; 95% CI: 0.1%-11.2%) patients without a history of PE or DVT and with a normal A-a gradient had PE., Conclusions: A normal A-a gradient among patients without a history of PE or DVT makes the diagnosis of PE unlikely. Further diagnostic evaluation may be unnecessary in this subgroup of patients.

Purpose: To examine the controversial association of gallstones, cholecystectomy and colorectal cancer. Methodologic explanations for the association include ascertainment bias, unequal diagnostic testing, and necropsy selection bias. Necropsy screening, which eliminates unequal diagnostic testing and ascertainment bias and reduces necropsy selection bias, was used to study this controversy., Methods: Adult necropsies at the University of Kansas Medical Center from 1950 to 1984 were reviewed. Patients with colorectal cancer, gallstones, or who had cholecystectomy during life were excluded. The remaining patients were those in whom neither colorectal cancer nor gallstones were suspected during life (reducing selection bias). The occurrence of gallstones and colorectal cancer among these individuals was then determined (reducing ascertainment bias and unequal diagnostic testing)., Results: Of 7485 persons receiving necropsy, 239 had colorectal cancer diagnosed during life and an additional 604 had gallstones or cholecystectomy, leaving 6642 patients available for study. Overall, no association between colorectal cancer and gallstones was found. In women, gallstones were associated with colorectal cancer; 6/447 (1.3%) with gallstones had colorectal cancer compared with 11/2259 (0.4%) without gallstones who had colorectal cancer, p = 0.048, odds ratio 2.78 (95% CI 0.84-8.25). A stronger association was found between right-sided colorectal cancer and gallstones (odds ratio 6.79, 95% CI 1.14-46.46)., Conclusions: These data suggest an association between gallstones and colorectal cancer among women. Gallstones may indicate patients at higher risk for colorectal cancer. Studies associating cholecystectomy with colorectal cancer may be explained--not by ascertainment bias--but, rather, by susceptibility bias. The reason for the cholecystectomy (gallstones) may be the correct association and not the cholecystectomy itself.

The role of ionic calcium (Ca2+) in the rebound secretion of growth hormone (GH) following termination of somatostatin (SRIF) administration was investigated in vitro by perifusion of acutely dispersed rat anterior pituitary cells. Treatment with 10 nM SRIF for 40 min significantly reduced the mean GH secretory rate by 3.3 +/- 0.2 ng min-1 representing a 58% decrease from baseline (p < 0.01). Following the withdrawal of SRIF treatment, GH levels surged 3- to 5-fold relative to baseline with the mean secretion rate increasing by 4.5 +/- 0.99 ng min-1 (p < 0.05). GH rebound secretion following SRIF removal from the perifusion medium was completely abolished (p < 0.01) when zero calcium medium (0 Ca2+) or medium containing 2 mM cobalt chloride (Co2+) were administered after SRIF termination. Perifusion with 0 Ca2+ caused the GH release rate to return to above baseline levels. In contrast, Co2+ perifusion caused the GH secretion rate to remain at the level observed during SRIF treatment (-4.52 +/- 0.38 ng min-1 relative to baseline; p < 0.01). Similarly, when cells were exposed to Co2+ alone, a reduction in the rate of GH secretion (-3.96 +/- 0.56 ng min-1; p < 0.01) was evident. After termination of Co2+ treatment, either by itself or following SRIF pretreatment, and upon changing from 0 Ca2+ to normal calcium-containing medium following SRIF pretreatment, a significant overshoot in GH release similar to SRIF withdrawal-induced GH release was observed (p < 0.05 and 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

A simple, three-part process is described for the working nurse to identify the activities of each day, order the activities by importance, and then redesign their work day for better time management. The article also describes how to be sure that the employer's values are in sync with the nurse's.

Objective: The epidemiologic necropsy measures the occurrence of unsuspected disease through the examination of necropsy records of patients who died for other reasons. The estimates of unsuspected disease derived from the epidemiologic necropsy should approximate what actually occurs in the living population., Design/setting: To test this hypothesis, all necropsy records of adult patients at the University of Kansas Medical Center from 1950 to 1984 were examined for the presence of gallstones. Patients with previous cholecystectomy or whose gallstones were diagnosed during life were excluded. The data were stratified by age and race and compared with those of a screening survey from Canada, a surgical series from New York, two screening surveys from Italy, and one from Denmark. The crude necropsy detection rates and the rates from the screening surveys were standardized to the 1970 federal census for Kansas City., Results/conclusions: The standardized occurrence rates were similar and suggest that the epidemiologic necropsy accurately assesses the occurrence of asymptomatic gallstones in the living population, thus strengthening its validity as a research tool.

This study represents a review of 33 patients seen at the Kingston Public Hospital, Jamaica, with penetrating cardiac injuries over a 7-year period from 1982 to 1989. Male patients between the ages of 12 and 30 years accounted for more than 80 per cent of cases. A history of syncope associated with haemodynamic instability were the predominant clinical features on presentation. The clinical triad of raised central venous pressure, muffled heart sounds, and low blood pressure levels was present in 33 per cent of the patients with cardiac tamponade. Pulsus paradoxus was not a significant diagnostic sign. Most of the injuries were stab wounds to the left anterior chest. The most commonly injured heart chamber was the right ventricle (48 per cent). Pericardiocentesis was not helpful in making the diagnosis and was only performed as a resuscitative measure in unstable patients prior to thoracotomy. Cardiorrhaphy was performed in the majority of patients through a left anterior lateral thoracotomy with median sternotomy being used only for suspected hilar injuries. A high index of suspicion in patients with penetrating thoracic trauma with expeditious thoracotomy will result in the greatest salvage rate.

The hypothesis has been put forward that genotoxic aromatic amines which induce the P450 I family of haemoproteins, the major enzyme involved in their bioactivation, are more likely to be carcinogenic when compared to those chemicals that fail to do so. Induction of the hepatic P450 I family of proteins by carcinogenic aromatic amines and their non-carcinogenic isomers and analogues was investigated in the rat and correlated to their carcinogenic potential. The activity of the P450 I A1 protein was monitored by the O-deethylation of ethoxyresorufin and of the P450 I A2 by the activation of the premutagen Glu-P-1 to mutagenic intermediates in the Ames test. Results were always confirmed immunologically in Western blots employing antibodies to rat P450 I A1 which recognize both proteins of the P450 I family. With all groups of chemicals used in the present study, the members displaying carcinogenicity were always the more potent inducers, while the non-carcinogenic isomers or analogues displayed little or no induction. It appears that a relationship exists between the carcinogenicity of aromatic amines and their ability to induce hepatic P450 I activity.

Despite improved modern diagnostic techniques, many patients with primary lung cancer escape detection of their disease during life. In a review of postmortem records at a university hospital, 28 percent of 153 primary lung cancers found at necropsy had not been diagnosed while the patient was alive. The male/female ratio was 1.3 in this undetected group, compared with 2.3 in the detected group. The main clinical features that seemed to lead to nondiagnosis were a terminal clinical state in patients who were too sick for further diagnostic searches, the absence of suggestive primary symptoms, a chest x-ray film interpreted as not showing primary lung cancer, and the absence of cigarette smoking. Among the patients with lung cancer at necropsy, the proportion of nonsmokers was higher in the previously undiagnosed group than in the group with antemortem diagnoses, even when patients were stratified for primary symptoms. The findings suggest the need for diagnostic alertness to the possibility that curable lung cancer can occur in patients who have a positive chest-film lesion but who are nonsmokers and who lack typical symptoms.

In previous research, we have demonstrated the value of using necropsy "surprise" lung cancer cases, in those in whom lung cancer was not suspected during life, to estimate the size and composition of the "reservoir" of undetected lung cancer in the general population. The current research was done to determine the characteristics and consequences of secular changes over time in the composition of the lung cancer "reservoir." The results suggest that further advances in diagnostic technology will enhance detection during life of the large "reservoir" of resectable lung cancer, particularly in women. With the increased detection of these reservoir cases during life, the statistical occurrence rates for lung cancer will seem to increase, but survival rates will seem to improve because more of the detected cases will be resectable.

A hypertensive episode precipitated by avocados in a patient on tranylcypromine is described. The patient complained of severe throbbing headache, chest pain, and diaphoresis upon visiting the emergency room. Intravenous phentolamine was administered repeatedly to treat elevated blood pressure. Approximately 4 1/2 hours later, the patient's blood pressure stabilized, and he was released after a short period of observation. This is the first documented case of avocado induced hypertensive crisis.

The epidemiologic use of necropsy data has been inhibited by the belief that the information is demographically biased. This study was undertaken to investigate whether patients who have died and who have undergone a necropsy are representative of hospital deaths. In a review of all hospital and necropsied deaths from 1962 to 1981 in adult patients at the University of Kansas Medical Center, Kansas City, it was found that 7393 hospital patients died and 4122 underwent necropsy (56%), with similar proportions in both men and women. The mean age of those undergoing necropsy was slightly younger: 60 years vs 62 years in men and 57 years vs 59 years in women. The proportion of necropsies performed was relatively similar for whites (57%) and nonwhites (51%). Although the large sample size made all these differences "statistically significant," there were no clinically relevant differences with regard to gender, age, or race. These findings confirm a previous study at another institution and suggest that a demographic bias does not distort necropsy population data compared with data of the population of hospital deaths.

The association between DES and the development of clear cell vaginal carcinoma may have several alternative explanations rather than a cause- and-effect relation. One important possibility is that susceptibility bias, arising from reasons for use of the drug in a problem pregnancy, is a prime source of the observed effect in the case-control studies. Rather than being a cause of clear cell vaginal carcinoma, exposure to DES would serve as a prognostic "marker" to identify women born of problem pregnancies that increased their risk for development of the disease. Since medical advances in prenatal and perinatal care allowed these problem pregnancies to be carried to the term delivery of a viable child, DES may have been associated with an increased occurrence of clear cell vaginal carcinoma--without causing the disease. Another alternative hypothesis is needed to account for the high rates of reported previous exposure to DES in the case subjects of the two case-control studies. These rates may have been elevated by some form of interviewer bias or recall bias. The relatively high incidence of clear cell vaginal carcinoma that would be expected from the results of these case-control studies has not been observed in cohort studies. No instances of clear cell vaginal carcinoma have thus far been found in suitably assembled cohorts of women exposed to DES in utero. The history of science contains abundant examples of fervently held beliefs about cause- and-effect relations that were later found to be erroneous. The existing evidence of a DES/vaginal cancer relation is currently too weak for the causal role of DES to be regarded as established. To get better evidence, the problems of biased comparison and biased data can be addressed in at least three ways. The first is to carry out an appropriately objective new case-control study, with suitably chosen control subjects; the second is to study the issue of susceptibility bias by getting additional information about the occurrence of problem pregnancies in the mothers of patients with clear cell vaginal carcinoma who were not exposed to DES; the third is to review past tissue specimens from previously diagnosed genital adenocarcinomas, searching for clear cell cancers that may have been unrecognized. Until the suspected biases are addressed and either confirmed or refuted, the relation between DES and clear cell vaginal carcinoma remains a statistical association that is unaccompanied by the quality of evidence required for scientific conclusions.

Recent advances in technology have not substantially changed the relatively low survival rate associated with acute renal failure (ARF). Several clinical prognostic variables and multivariate models have been reported to predict survival in individual patients, but these are either cumbersome to use or restrictive in their application. A straightforward clinical index has been developed to predict survival in ARF based on data obtained for all patients receiving dialysis for ARF at the University of Kansas Medical Center from November 1979 through October 1985. During this period, 126 patients received dialysis for ARF, with an overall survival of 25% (32/126). There were no significant differences between survivors and nonsurvivors in age, gender, or indication for dialysis. Eleven variables were statistically related to survival, and were reduced to five when clinically similar variables were combined or eliminated. A clinical survival index was based on these five easily determined variables that were significantly related to survival: systolic blood pressure less than or equal to 110 mm Hg, assisted ventilation, congestive heart failure, proven or suspected sepsis, and gastrointestinal (GI) dysfunction (bleeding, ileus, obstruction, or recent abdominal surgery). Survival was directly related to the number of factors present: zero, 62% (8/13); one, 44% (8/18); two, 30% (10/33); three, 19% (5/26); four, 0% (0/20); and five, 6% (1/16). This straightforward index, derived from easily obtained clinical data, is useful for judging survival prognosis in patients with ARF severe enough to warrant treatment with dialysis.

Recent reports have suggested a minimal difference in demographics between hospital deaths undergoing necropsy and those that do not. In order to assess whether the clinical diagnosis at death influenced the decision to request necropsy in deaths occurring in the hospital, a 10% sample of all adult necropsies at the University of Kansas Medical Center (Kansas City) from 1962 through 1981 was obtained. These patients (cases) were matched by age, race, sex, and date of death to hospital deaths not undergoing necropsy (controls). The charts were reviewed, and the primary diagnosis at death was ascertained and categorized into one of the 14 categories of the International Classification of Diseases. There were 412 case-control pairs, with 237 men and 175 women in each group. Most patients were classified under the headings Circulatory (142 cases vs 140 controls) and Neoplasm (143 cases vs 148 controls), followed by Respiratory (21 cases vs 33 controls) and Digestive (44 cases vs 28 controls). Overall, no statistically significant differences were observed between cases and controls. There were no gender-specific differences in all but two of the categories. In men, the controls had more patients classified under the heading injury (19 vs seven). In women, the control group had more patients classified under the heading Respiratory (14 vs four). Because of multiple comparisons, these findings could have occurred by chance. These data suggest that the primary diagnosis at death is not a source of bias in the selection for necropsy. Consequently, necropsy-selection bias, if it exists, may be due to other factors, such as the complexity of the patient's clinical course.

A review of 60 patients with primary small bowel tumours seen at the University Hospital, Jamaica, during the 15 year period 1971-1985, revealed that adenocarcinoma was the commonest tumour (27%), followed by smooth muscle tumour (23%), and carcinoids (11%). There were 32 malignant and 28 benign tumours. The mean age at presentation was 56 years, with a range of 4 to 85 years. The most common clinical presentation was intestinal obstruction, followed by pain, weight loss, abdominal mass and intussusception. In the majority of patients the diagnosis was not made preoperatively, and 80% with adenocarcinoma had lymph node metastases. Increased awareness of the diagnosis in symptomatic patients may result in improved survival.

Because prognostic adjustment in epidemiologic studies of disease etiology has usually been limited to matchings or stratifications based on demographic characteristics, clinical sources of susceptibility bias have received little attention. This may have led to an incorrect association in two prominent epidemiologic relationships: that between clear-cell vaginal carcinoma and the use of diethylstilbestrol to treat women with bleeding or previous pregnancy loss; and that in the conflicting results of the studies linking sex steroids to the risk of birth defects. The recognition and management of susceptibility bias requires attention to the patients' clinical status at the time of exposure to the alleged causative agent, and also requires collecting and analyzing clinical data excluded or ignored in most epidemiologic studies. To avoid susceptibility bias, data about bleeding, threatened abortion, and other clinical reasons for prescribing therapy are needed for the appropriate matchings or stratifications.

Residency training programs in Internal Medicine require resident attendance in a continuity clinic. This inevitably engenders conflicts between scheduling in the ambulatory clinic and the required teaching activities of the in-patient services. Some of the conflicts can be resolved by allowing the in-patient service directors to indicate preferred plans for their residents to attend in the continuity clinic. With this plan, scheduling becomes quite complicated. A computer program is presented with coordinates these service requests with ambulatory clinic scheduling. As a result, a given resident may have his/her clinic day changed on different rotations. The program automatically arbitrates conflicts and publishes the attendance dates for the entire academic year. This information is supplied to the appointment desk so that patients can be scheduled accordingly. This system has resulted in a 74% continuity rate and improved satisfaction by both residents and staff.