Communicating the Imperfect Diagnostic Accuracy of COVID-19 Rapid Antigen Self-Tests: An Online Randomized Experiment

OBJECTIVE

To investigate the potential impacts of optimizing coronavirus disease 2019 (COVID-19) rapid antigen test (RAT) self-testing diagnostic accuracy information.

DESIGN

Online randomized experiment using hypothetical scenarios: in scenarios 1 to 3 (RAT result positive), the posttest probability was considered to be very high (likely true positives), and in scenarios 4 and 5 (RAT result negative), the posttest probability was considered to be moderately high (likely false negatives).

SETTING

December 12 to 22, 2022, during the mixed-variant Omicron wave in Australia.

PARTICIPANTS

Australian adults. Intervention: diagnostic accuracy of a COVID-19 self-RAT presented in a health literacy-sensitive way; usual care: diagnostic accuracy information provided by the manufacturer; control: no diagnostic accuracy information.

MAIN OUTCOME MEASURE

Intention to self-isolate.

RESULTS

A total of 226 participants were randomized (control n = 75, usual care n = 76, intervention n = 75). More participants in the intervention group correctly interpreted the meaning of the diagnostic accuracy information (P = 0.08 for understanding sensitivity, P < 0.001 for understanding specificity). The proportion who would self-isolate was similar across scenarios 1 to 3 (likely true positives). The proportion was higher in the intervention group than in the control for scenarios 4 and 5 (likely false negatives). These differences were not statistically significant. The largest potential effect was seen in scenario 5 (dinner party with confirmed cases, the person has symptoms, negative self-RAT result), with 63% of the intervention group and 49% of the control group indicating they would self-isolate (absolute difference 13.3%, 95% confidence interval: -2% to 30%, P = 0.10).

CONCLUSION

Health literacy sensitive formatting supported participant understanding and recall of diagnostic accuracy information. This may increase community intentions to self-isolate when there is a likely false-negative self-RAT result. Trial registration: Australia New Zealand Clinical Trial Registry (ACTRN12622001517763).

HIGHLIGHTS

Community-based diagnostic accuracy studies of COVID-19 self-RATs indicate substantially lower sensitivity (and higher risk of false-negative results) than the manufacturer-supplied information on most government public Web sites.This online randomized study found that a health literacy-sensitive presentation of the imperfect diagnostic accuracy COVID-19 self-RATs supported participant understanding and recall of diagnostic accuracy information.Health literacy-sensitive presentation may increase community intentions to self-isolate after a negative test result where the posttest probability is still moderately high (i.e., likely false-negative result).To prevent the onward spread of infection, efforts to improve communication about the high risk of false-negative results from COVID-19 self-RATs are urgently needed.

Using the Behaviour Change Wheel to identify barriers and targeted strategies to improve adherence in randomised clinical trials: The example of MEL-SELF trial of patient-led surveillance for melanoma

BACKGROUND

Adherence to self-management interventions is critical in both clinical settings and trials to ensure maximal effectiveness. This study reports how the Behaviour Change Wheel may be used to assess barriers to self-management behaviours and develop strategies to maximise adherence in a trial setting (the MEL-SELF trial of patient-led melanoma surveillance).

METHODS

The Behaviour Change Wheel was applied by (i) using the Capability, Opportunity, Motivation-Behaviour (COMB) model informed by empirical and review data to identify adherence barriers, (ii) mapping identified barriers to corresponding intervention functions, and (iii) identifying appropriate behaviour change techniques and developing potential solutions using the APEASE (Affordability, Practicability, Effectiveness and cost-effectiveness, Acceptability, Side-effects and safety, Equity) criteria.

RESULTS

The target adherence behaviour was defined as conducting a thorough skin self-examination and submitting images for teledermatology review. Key barriers identified included: non-engaged skin check partners, inadequate planning, time constraints, low self-efficacy, and technological difficulties. Participants' motivation was positively influenced by perceived health benefits and negatively impacted by emotional states such as anxiety and depression. We identified the following feasible interventions to support adherence: education, training, environmental restructuring, enablement, persuasion, and incentivisation. Proposed solutions included action planning, calendar scheduling, alternative dermatoscopes, optimised communication, educational resources in various formats to boost self-efficacy and motivation and optimised reminders (which will be evaluated in a Study Within A Trial (SWAT)).

CONCLUSION

The Behaviour Change Wheel may be used to improve adherence in clinical trials by identifying barriers to self-management behaviours and guiding development of targeted strategies.

Strategies to Improve Adherence to Skin Self-examination and Other Self-management Practices in People at High Risk of Melanoma: A Scoping Review of Randomized Clinical Trials

Importance

Adherence, both in research trials and in clinical practice, is crucial to the success of interventions. There is limited guidance on strategies to increase adherence and the measurement and reporting of adherence in trials of melanoma self-management practices.

Objective

This scoping review aimed to describe (1) strategies to improve adherence to self-management practices in randomized clinical trials of people at high risk of melanoma and (2) measurement and reporting of adherence data in these trials.

Evidence Review

Four databases, including MEDLINE, Embase, CENTRAL, and CINAHL, were searched from inception to July 2022. Eligible studies were randomized clinical trials of self-monitoring interventions for early detection of melanoma in people at increased risk due to personal history (eg, melanoma, transplant, dysplastic naevus syndrome), family history of melanoma, or as determined by a risk assessment tool or clinical judgment.

Findings

From 939 records screened, 18 eligible randomized clinical trials were identified, ranging in size from 40 to 724 participants, using a range of adherence strategies but with sparse evidence on effectiveness of the strategies. Strategies were classified as trial design (n = 15); social and economic support (n = 5); intervention design (n = 18); intervention and condition support (n = 10); and participant support (n = 18). No strategies were reported for supporting underserved groups (eg, people who are socioeconomically disadvantaged, have low health literacy, non-English speakers, or older adults) to adhere to self-monitoring practices, and few trials targeted provider (referring to both clinicians and researchers) adherence (n = 5). Behavioral support tools included reminders (n = 8), priority-setting guidance (n = 5), and clinician feedback (n = 5). Measurement of adherence was usually by participant report of skin self-examination practice with some recent trials of digital interventions also directly measuring adherence to the intervention through website or application analytic data. Reporting of adherence data was limited, and fewer than half of all reports mentioned adherence in their discussion.

Conclusions and Relevance

Using an adaptation of the World Health Organization framework for clinical adherence, this scoping review of randomized clinical trials identified key concepts as well as gaps in the way adherence is approached in design, conduct, and reporting of trials for skin self-examination and other self-management practices in people at high risk of melanoma. These findings may usefully guide future trials and clinical practice; evaluation of adherence strategies may be possible using a Study Within A Trial (SWAT) framework within host trials.

Assessing the Potential for Patient-led Surveillance After Treatment of Localized Melanoma (MEL-SELF): A Pilot Randomized Clinical Trial

IMPORTANCE

Patient-led surveillance is a promising new model of follow-up care following excision of localized melanoma.

OBJECTIVE

To determine whether patient-led surveillance in patients with prior localized primary cutaneous melanoma is as safe, feasible, and acceptable as clinician-led surveillance.

DESIGN, SETTING, AND PARTICIPANTS

This was a pilot for a randomized clinical trial at 2 specialist-led clinics in metropolitan Sydney, Australia, and a primary care skin cancer clinic managed by general practitioners in metropolitan Newcastle, Australia. The participants were 100 patients who had been treated for localized melanoma, owned a smartphone, had a partner to assist with skin self-examination (SSE), and had been routinely attending scheduled follow-up visits. The study was conducted from November 1, 2018, to January 17, 2020, with analysis performed from September 1, 2020, to November 15, 2020.

INTERVENTION

Participants were randomized (1:1) to 6 months of patient-led surveillance (the intervention comprised usual care plus reminders to perform SSE, patient-performed dermoscopy, teledermatologist assessment, and fast-tracked unscheduled clinic visits) or clinician-led surveillance (the control was usual care).

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of eligible and contacted patients who were randomized. Secondary outcomes included patient-reported outcomes (eg, SSE knowledge, attitudes, and practices, psychological outcomes, other health care use) and clinical outcomes (eg, clinic visits, skin surgeries, subsequent new primary or recurrent melanoma).

RESULTS

Of 326 patients who were eligible and contacted, 100 (31%) patients (mean [SD] age, 58.7 [12.0] years; 53 [53%] men) were randomized to patient-led (n = 49) or clinician-led (n = 51) surveillance. Data were available on patient-reported outcomes for 66 participants and on clinical outcomes for 100 participants. Compared with clinician-led surveillance, patient-led surveillance was associated with increased SSE frequency (odds ratio [OR], 3.5; 95% CI, 0.9 to 14.0) and thoroughness (OR, 2.2; 95% CI, 0.8 to 5.7), had no detectable adverse effect on psychological outcomes (fear of cancer recurrence subscale score; mean difference, -1.3; 95% CI, -3.1 to 0.5), and increased clinic visits (risk ratio [RR], 1.5; 95% CI, 1.1 to 2.1), skin lesion excisions (RR, 1.1; 95% CI, 0.6 to 2.0), and subsequent melanoma diagnoses and subsequent melanoma diagnoses (risk difference, 10%; 95% CI, -2% to 23%). New primary melanomas and 1 local recurrence were diagnosed in 8 (16%) of the participants in the intervention group, including 5 (10%) ahead of routinely scheduled visits; and in 3 (6%) of the participants in the control group, with none (0%) ahead of routinely scheduled visits (risk difference, 10%; 95% CI, 2% to 19%).

CONCLUSIONS AND RELEVANCE

This pilot of a randomized clinical trial found that patient-led surveillance after treatment of localized melanoma appears to be safe, feasible, and acceptable. Experiences from this pilot study have prompted improvements to the trial processes for the larger trial of the same intervention.

TRIAL REGISTRATION

http://anzctr.org.au Identifier: ACTRN12616001716459.

Can patient-led surveillance detect subsequent new primary or recurrent melanomas and reduce the need for routinely scheduled follow-up? A protocol for the MEL-SELF randomised controlled trial

BACKGROUND

Most subsequent new primary or recurrent melanomas might be self-detected if patients are trained to systematically self-examine their skin and have access to timely medical review (patient-led surveillance). Routinely scheduled clinic visits (clinician-led surveillance) is resource-intensive and has not been shown to improve health outcomes; fewer visits may be possible if patient-led surveillance is shown to be safe and effective. The MEL-SELF trial is a randomised controlled trial comparing patient-led surveillance with clinician-led surveillance in people who have been previously treated for localised melanoma.

METHODS

Stage 0/I/II melanoma patients (n = 600) from dermatology, surgical, or general practice clinics in NSW Australia, will be randomised (1:1) to the intervention (patient-led surveillance, n = 300) or control (usual care, n = 300). Patients in the intervention will undergo a second randomisation 1:1 to polarised (n = 150) or non-polarised (n = 150) dermatoscope. Patient-led surveillance comprises an educational booklet, skin self-examination (SSE) instructional videos; 3-monthly email/SMS reminders to perform SSE; patient-performed dermoscopy with teledermatologist feedback; clinical review of positive teledermoscopy through fast-tracked unscheduled clinic visits; and routinely scheduled clinic visits following each clinician's usual practice. Clinician-led surveillance comprises an educational booklet and routinely scheduled clinic visits following each clinician's usual practice. The primary outcome, measured at 12 months, is the proportion of participants diagnosed with a subsequent new primary or recurrent melanoma at an unscheduled clinic visit. Secondary outcomes include time from randomisation to diagnosis (of a subsequent new primary or recurrent melanoma and of a new keratinocyte cancer), clinicopathological characteristics of subsequent new primary or recurrent melanomas (including AJCC stage), psychological outcomes, and healthcare use. A nested qualitative study will include interviews with patients and clinicians, and a costing study we will compare costs from a societal perspective. We will compare the technical performance of two different models of dermatoscope (polarised vs non-polarised).

DISCUSSION

The findings from this study may inform guidance on evidence-based follow-up care, that maximises early detection of subsequent new primary or recurrent melanoma and patient wellbeing, while minimising costs to patients, health systems, and society.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12621000176864 . Registered on 18 February 2021.

Reduction of the onset response in kilohertz frequency alternating current nerve block with amplitude ramps from non-zero amplitudes

BACKGROUND

Kilohertz frequency alternating current (KHFAC) waveforms reversibly block conduction in mammalian peripheral nerves. The initiation of the KHFAC produces nerve activation, called the onset response, before complete block occurs. An amplitude ramp, starting from zero amplitude, is ineffective in eliminating this onset activity. We postulated that initiating the ramp from a non-zero amplitude would produce a different effect on the onset.

METHODS

Experiments were conducted in an in vivo rat model. KHFAC was applied at supra block threshold amplitudes and then reduced to a lower sub block amplitude (25, 50, 75 and 90% of the block threshold amplitude). The amplitude was then increased again to the original supra block threshold amplitude with an amplitude ramp. This ramp time was varied for each of the amplitude levels tested.

RESULTS

The amplitude ramp was successful in eliminating a second onset. This was always possible for the ramps up from 75 and 90% block threshold amplitude, usually from 50% but never from 25% of the block threshold amplitude.

CONCLUSIONS

This maneuver can potentially be used to initiate complete nerve block, transition to partial block and then resume complete block without producing further onset responses.

Expression of luteinizing hormone/human chorionic gonadotropin receptor gene in benign prostatic hyperplasia and in prostate carcinoma in humans

The findings that normal rat prostates express functional LH/hCG receptors led us to test the hypothesis that benign prostatic hyperplasia (BPH) and prostate carcinomas may also express this receptor gene. The data revealed the presence of LH/hCG receptor transcripts and receptor protein in normal and hyperplastic but not in atrophic glands present in BPH tissue. Smooth muscle and blood vessels in stroma of BPH tissue also contained receptors. Prostate carcinomas contain lower and more heterogeneous receptor levels than BPH tissue. Two human prostate cancer cell lines (LNCaP and DU 145) that were investigated showed the presence of a major 4.5-kilobase transcript and several minor transcripts and also the protein of LH/hCG receptors. However, androgen-sensitive LNCaP cells contained more receptors than androgen-insensitive DU 145 cells. In summary, we demonstrate for the first time that BPH and prostate cancer tissues and cell lines express LH/hCG receptor gene. These findings suggest that higher LH levels in aged men may play a role in BPH and/or prostate carcinomas.

Harvey ras (H-ras) point mutations are induced by 4-nitroquinoline-1-oxide in murine oral squamous epithelia, while squamous cell carcinomas and loss of heterozygosity occur without additional exposure

Tumorigenesis is a multistep genetic process requiring several somatic mutations for neoplastic transformation. These mutations appear to be sequential, random, and independent events. However, we find linked, nonrandom ras mutations occurring during 4-nitroquinoline-1-oxide-induced tumorigenesis months after exposure to the carcinogen had ceased. The carcinogen had been topically applied to the oral cavity of CBA mice for 4 to 16 weeks. Dysplasia developed after 24 weeks, and carcinoma in situ and squamous cell carcinoma developed after 28 weeks. H-ras mutations were detected in 13 of 25 tissue specimens (10 of 14 invasive carcinomas and 2 of 4 carcinoma in situ, 1 of 5 dysplastic tissue, and 0 of 2 normal tissues). Approximately one-half of the tumors had G to A point mutations at codon 12 of the cellular H-ras proto-oncogene on mouse chromosome 7. None had codon 11, 13, or 61 mutations. Loss of heterozygosity occurred in 5 of 14 invasive cancers. Larger invasive squamous cell carcinomas consistently lost the wild-type allele, whereas preneoplastic lesions and small tumors were heterozygous for ras. This suggests a causal relationship between carcinogen treatment, H-ras activation, and initiation of tumorigenesis. The wild-type allele in mouse chromosome 7 is lost with the progression of tumorigenesis long after exposure to the carcinogen. Thus, loss of heterozygosity of the ras gene appears to occur without multiple carcinogen-induced mutations, i.e., as a result of a cascade of events induced by an earlier ras mutation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Increased expression of human chorionic gonadotropin/human luteinizing hormone receptors in adenomyosis

Adenomyosis is a benign disease in women in which myometrium is invaded by endometrial glands and stroma. Our laboratory recently demonstrated that normal human endometrial glands and stroma express the hCG/LH receptor gene. This prompted us to investigate whether invading glands and stroma in adenomyosis also express this receptor gene. Fifteen hysterectomy specimens with confirmed histological diagnosis of adenomyosis were examined for hCG/LH receptors by in situ hybridization and immunocytochemistry. The results showed that invading glands contained more receptor mRNA and receptor protein than noninvading glands in the same endometrium. However, the degree of difference between invading and noninvading glands varied among the patients. The higher receptor expression in invading glands is specific because the invading and noninvading stroma showed similar receptor expression, invading and noninvading glands showed similar expression of cadherin, a cell adhesion receptor, and ectopic and eutopic endometrial glands from endometriosis showed similar hCG/LH receptor expression. In summary, the present results demonstrate that invading endometrial glands in adenomyosis selectively express more hCG/LH receptor mRNA and immunoreactive receptor protein than noninvading glands. Whether this increased receptor expression is the cause or a consequence of myometrial invasion of glands in unknown.

Short-term dietary copper deficiency does not inhibit angiogenesis in tumours implanted in striated muscle

The effect of dietary copper deficiency on tumour growth, neovascularisation and microvascular integrity was studied in the rat cremaster muscle. Male, weanling Sprague-Dawley rats were fed purified diets which were copper deficient (< 0.5 micrograms g-1 of diet) or copper adequate (5 micrograms g-1 of diet). Seven days after initiation of diets, a chondrosarcoma was implanted in the cremaster muscle of each rat. Five, 10 or 20 days after tumour implantation, rats were anesthetised and their cremasters prepared for observation by intravital microscopy. Intraarterial injection of fluorescein isothiocyanate-conjugated albumin and subsequent observation of fluorescence in the perivascular space indicated no difference in microvascular albumin leakage between the tumour vasculature of copper deficient and copper adequate rats. Neither tumour growth (assessed by wet weight), vascular density (assessed by light microscopy), nor any ultrastructural characteristics of the tumour or its vasculature (assessed by electron microscopy) were affected by copper deficiency. In view of findings by others which indicate changes in tumour characteristics with copper deficiency, we conclude that the copper dependency of tumour growth and vascularisation is a function of the type of tumour, the host tissue, or the conditions of copper depletion.

Postinfarction rupture of the left ventricular free wall: clinicopathologic correlates in 100 consecutive autopsy cases

Among 100 consecutive autopsied cases of postinfarction rupture of the left ventricular free wall, 51% of the deaths were in-hospital and 49% were out of hospital. There were 51 men (mean age, 72 years) and 49 women (mean age, 76 years); 81% had multivessel disease. All had severe obstruction of at least one major epicardial coronary artery (98 atherosclerotic, one thrombotic, and one embolic). Acute coronary thrombosis was present in 73 cases and occurred on an atherosclerotic plaque in 72, 49 (68%) of which had associated plaque rupture. In 83 cases, the ruptured infarction represented the subject's first myocardial infarction. Despite a history of hypertension in 55 cases, appreciable left ventricular hypertrophy was observed in only 19 cases. By histopathologic age of infarction, 13 ruptures occurred during the first day, 45 between days 2 and 5, and 22 on days 6 and 7; thus, 58% occurred within 5 days and 80% within 7 days. The mid-ventricle was the most frequent site of rupture (66%). Ruptures most frequently involved the lateral aspect of the left ventricular free wall (44%). In 66 cases, the rupture tract occurred along the interface between viable and necrotic myocardium. Our findings support the observations of others that the risk factors for postinfarction left ventricular free wall rupture include age greater than 60 years, female gender, preexisting hypertension, absence of left ventricular hypertrophy, first myocardial infarction, and midventricular or lateral wall transmural infarctions.

Progressive microcirculatory changes caused by hypercholesterolemia in rats

The progressive microcirculatory changes caused by hypercholesterolemia were studied in the rat cremaster model by use of intravital microscopy. Male Sprague-Dawley rats were fed either a normal chow diet or a chow diet supplemented with 1% cholesterol and 0.5% cholic acid for 1, 3, or 5 wk before experimentation. After 3 wk on the diet, hypercholesterolemia produced a significantly decreased vasoconstrictor response to norepinephrine in both arterioles and venules. After 5 wk, there was also significantly reduced macromolecular leakage induced by exogenous histamine and compound 48/80 in the high-cholesterol group. However, there was no change in the degree of base-line macromolecular leakage. Platelet thrombi formation induced by light activation of intravascular fluorescein isothiocyanate tagged to bovine serum albumin was slightly increased by hypercholesterolemia. Despite these microcirculatory changes there was no microscopic evidence of atheromatous pathology after 5 wk on the cholesterol diet. These results suggest a progressive nonspecific receptor desensitization and decreased inflammatory response shortly after the initiation of elevated serum cholesterol but before any histological evidence of atherosclerosis.

Microvascular responses in copper-deficient rats

In this study on copper deficiency, the rat crewmaster microcirculation was used as a model for endogenous histamine release and platelet thrombi formation. Male Sprague-Dawley rats were fed either a copper-supplemented diet (CuS, 5 ppm) or a copper-deficient diet (CuD, 0 ppm) for 5 wk before experimentation. The crewmasters of anesthetized rats were spread in a Krebs-filed tissue bath. In venules of CuS animals, photoactivation of intravascular fluorescein isothiocyanate tagged to bovine serum albumin caused significant platelet aggregation and reduction of red blood cell column diameter (RBCCD) by 40 min and stasis of flow by 60 min. In CuD animals there was only minor platelet aggregation and no reduction in RBCCD. Platelet aggregometry studies did not demonstrate reduced platelet aggregation in the CuD group, suggesting that copper deficiency alters the endothelium to inhibit adhesion. Compound 48/80 (1.0 and 10.0 microgram/ml) induced macromolecular leakage in both CuS and CuD groups, with the response in the CuD animals being significantly greater. The results demonstrate that copper deficiency results in alterations of the regulatory mechanisms governing inflammation and thrombosis.

Aortoenteric fistulas. A study of 28 autopsied cases spanning 25 years

Among 28 autopsied patients with aortoenteric fistulas, the mean age was 67 years (range, 19 to 91 years) and 23 (82%) were men. The most common causes were aortobifemoral bypass grafts (16 cases [57%]) and gastrointestinal carcinomas (6 cases [21%]). Fistulas developed at proximal anastomosis sites in 15 of 16 patients with grafts and were associated with radiation injury in 3 of 6 patients with carcinomas. Aortoenteric fistulas involved the duodenum in 16 (57%), esophagus in 9 (32%), and other gastrointestinal sites in 3 patients (11%). They involved the abdominal aorta in 20 cases (71%) and descending thoracic aorta in 8 cases (29%). Exsanguination from aortoenteric fistulas was the cause of death in 23 cases (82%). Major risk factors for aortoenteric fistulas are aortic bypass grafts and gastrointestinal carcinomas.

The response of the rat urinary bladder microcirculation to photodynamic therapy

Light activation of dihematoporphyrin ether (photofrin II) has been used in the treatment of bladder tumors, yet the effects of this treatment on the normal urinary bladder microcirculation have not been determined. This study involved the use of in vivo television microscopy to observe the effects of light activation (530 to 560 nm., 175 mW/cm.) on the urinary bladder microcirculation of female Sprague-Dawley rats. Animals pretreated with dihematoporphyrin ether 30 minutes prior to light activation had high serum and low tissue concentrations of the photosensitizer and activation resulted in a statistically significant reduction of red blood cell column diameter in both arterioles and venules. The reduction was primarily due to mural thrombus formation with the occlusion remaining 60 minutes after activation. Animals pretreated 48 hours before activation had low serum and high tissue concentrations of dihematoporphyrin ether and activation had no microcirculatory effects apart from occasional platelet aggregation. These results suggest that the photodynamic effect on normal (non-neoplastic) tissue treated more than 48 hours after administration of dihematoporphyrin ether is probably due to a direct effect of light and the sensitizer on the smooth muscle of the bladder rather than an effect on the microcirculation.

Surgical pathology of the tricuspid valve: a study of 363 cases spanning 25 years

Surgical pathologic features of the tricuspid valve were reviewed in 363 patients who had undergone tricuspid valve replacement at our institution during the period 1963 through 1987. Valves were purely regurgitant in 74%, stenotic and regurgitant in 23%, and purely stenotic in 2%; two valves were neither stenotic nor regurgitant. Among 269 purely insufficient tricuspid valves, the four most common causes were postinflammatory disease (41%), congenital disorder (32%), pulmonary venous hypertension (21%), and infective endocarditis (4%). Of 92 cases of tricuspid stenosis, with or without regurgitation, postinflammatory disease was observed in 92%. Female patients accounted for 66% of the 363 cases, including 84% of those with postinflammatory disease and 64% of those with pulmonary venous hypertension. In contrast, male patients accounted for 73% of cases with endocarditis and 61% with congenital heart disease. Although postinflammatory disease accounted for 53% of the 363 cases, its relative frequency diminished from 79% during 1963 through 1967 to only 24% during 1983 through 1987. This trend may reflect the decreasing incidence of acute rheumatic fever reported in Western countries. During the same time interval, the relative frequency of congenital heart disease as a cause of tricuspid dysfunction increased from 7% to 53%, and it is currently the most common cause in our surgical population. This finding apparently reflects changes in patient referral practices and the development of new operative procedures.

Identification of atrial natriuretic factor within ventricular tissue in hamsters and humans with congestive heart failure

In normal mammals, atrial natriuretic factor (ANF) is present within atrial myocardial cells but is absent from ventricular myocardium. In primitive organisms ANF is present within both atria and ventricle, suggesting that the ventricle may participate both in the synthesis and release of the hormone. The current study was designed to test the hypothesis that ventricular ANF develops as a homeostatic response to intravascular volume overload. Studies were performed on cardiac tissue obtained from (i) normal and cardiomyopathic hamsters, (ii) autopsied humans with and without cardiac disease, and (iii) living humans with congestive heart failure (CHF) undergoing diagnostic right ventricular endomyocardial biopsy. The myocardium was examined for the presence of immunoreactive ANF using a two-stage immunohistochemical technique, with nonimmune rabbit sera used as a negative control. There was unequivocal evidence of focal subendocardial deposits of immunoreactive ANF present in both of the ventricles of all six cardiomyopathic hamsters, four of five autopsied human subjects with CHF, and five of seven biopsied humans. No immunoreactive ANF was observed within the ventricular myocardium of control hamsters or normal humans. Utilizing crude tissue homogenates and radioimmunoassay techniques, the quantity of ANF was determined in cardiac atria, ventricles, and noncardiac skeletal muscle. Heart failure is characterized by a reduction in atrial ANF and an increase in ventricular ANF. This study demonstrates immunoreactive ANF is present within the ventricular myocardium in cardiomyopathic hamsters and humans with CHF, and suggests that the ventricle may be capable of responding to chronic volume overload by producing ANF.

Malignant neoplastic emboli to the coronary arteries: report of two cases and review of the literature

Two patients were seen with malignant neoplastic emboli to the coronary arteries. One, a 61-year-old woman with a malignant fibrous histiocytoma of the thigh and a solitary pulmonary metastatic lesion, died of an acute myocardial infarction due to a neoplastic coronary embolus after lobectomy. The other, a 51-year-old woman with bronchogenic adenocarcinoma, died of extensive cerebral metastases. At autopsy, she also was found to have had an acute myocardial infarction associated with a neoplastic coronary embolus.

Sudden death as the initial manifestation of primary pulmonary hypertension. Report of four cases

Four autopsy cases are presented in which sudden death was the initial manifestation of primary pulmonary hypertension. The arteriopathy was plexogenic in two cases (a 3-year-old girl and a 16-year-old boy) and was thrombotic in two other cases (55- and 59-year-old women). The diagnosis of primary pulmonary hypertension, particularly in forensic cases, requires that the pathologist be especially aware of the possibility and that a careful evaluation of multiple sections of lung be performed. Determination of the histopathologic type also is important because some forms of the disease may be familial and may be treatable in other family members if they are detected early.

Traumatic rupture of Ionescu-Shiley aortic valve after the Heimlich maneuver

A 74-year-old woman who had undergone aortic valve replacement with an Ionescu-Shiley bioprosthesis was evaluated and treated because aortic insufficiency developed after the application of the Heimlich maneuver. Pathologic examination of the explanted valve disclosed a cuspid perforation and an adjacent tear of a second cusp at its insertion into the valve strut. Patients with unexplained acute prosthetic insufficiency should be questioned as to whether the Heimlich maneuver has been previously performed.

Temporal changes in the causes of aortic stenosis: a surgical pathologic study of 646 cases

Among 646 patients with pure aortic stenosis who underwent valve replacement at our institution between 1981 and 1985, the three most frequent causes were calcification of congenitally bicuspid aortic valves (38%), degenerative (senile) calcification of tricuspid aortic valves (33%), and postinflammatory (presumably rheumatic) calcification and fibrosis (24%). Among the 324 patients younger than 70 years of age, calcified bicuspid valves were observed in 50%. In contrast, among 322 patients 70 years of age or older, degenerative calcification accounted for 48% of the stenotic aortic valves. During the 5 years of the study, the relative frequency of postinflammatory disease decreased from 30% to 18%, and that of bicuspid valves decreased from 37% to 33%. In contrast, the relative frequency of degenerative calcification increased from 30% to 46%. Consequently, degenerative (senile) calcification is currently the most common cause of aortic stenosis among patients undergoing valve replacement at our institution. This finding may be related to changes in life expectancy in the general population, alterations in patient referral practices, and an increased willingness of surgeons to operate on older patients. Regardless of cause, the observed temporal changes in etiologic factors for aortic stenosis may indicate a potential source of increasing health-care costs among the elderly population.

Surgical pathology of the mitral valve: a study of 712 cases spanning 21 years

The gross surgical pathologic features of the mitral valve were reviewed in 712 patients who had undergone mitral valve replacement at our institution during 1965, 1970, 1975, 1980, and 1985. Among the 452 cases of mitral stenosis, either with or without mitral insufficiency, 99% were attributable to postinflammatory disease and 1% were related to congenital mitral stenosis. Among the 260 cases of pure mitral regurgitation, the two most common causes were a floppy valve (38%) and postinflammatory disease (31%). Moreover, a floppy valve was observed in 73% of the 59 examples of chordal rupture and in 38% of the 16 cases of infective endocarditis. Women accounted for 73% of the 452 cases of mitral stenosis and for 72% of the 530 cases of postinflammatory disease. In contrast, men accounted for 58% of the 260 cases of pure mitral regurgitation, including 76% of the floppy valves and 69% of the infected valves. During the 21 years spanned by the study, the relative frequency of postinflammatory mitral insufficiency progressively decreased, whereas that of floppy mitral valves increased. It is unclear whether aging, heredity, environmental factors, changes in the frequency of acute rheumatic fever, or changes in patient referral practices may account for this observation.

The relationship between atrial granularity and circulating atrial natriuretic peptide in hamsters with congestive heart failure

The BIO 14.6 strain of hamster is a model of familial cardiomyopathy complicated by congestive heart failure, sodium retention, and edema. In previous studies, bioassay techniques have demonstrated that the cardiac content of atrial natriuretic peptide (ANP) is reduced in these animals. On the basis of this observation, the syndrome of congestive heart failure has been hypothesized to be due to a deficiency in ANP. The current study was designed to correlate the cardiac content of ANP (determined by immunohistochemical techniques) with plasma circulating ANP (determined by radioimmunoassay). alpha-ANP antibodies were used for both determinations. The content of ANP in the atria was based on the degree of immunoreactive staining present (1 = lowest; 5 = highest), as graded by two observers. The mean granularity score of the cardiomyopathic hamsters was decreased (2.1 +/- 0.3) in comparison with that of age- and sex-matched control animals (3.5 +/- 0.5; P less than 0.05). In contrast, circulating immunoreactive ANP was higher in the hamsters with congestive heart failure than in the control animals--185.5 +/- 27.2 pg/ml versus 77.7 +/- 10.8 pg/ml (P less than 0.005). This study demonstrates that an inverse relationship exists between ANP content in the atria and circulating ANP. Furthermore, this study suggests that these hamsters with congestive heart failure are not deficient in ANP; rather, secretion of ANP is stimulated and storage of the peptide, represented by atrial granularity, is reduced.

Desmoplastic melanoma of the anus

To date a desmoplastic melanoma, an unusual variant of malignant melanoma, has been described only in the skin. The present report describes a case of desmoplastic melanoma that arose in the anal canal. The patient was without evidence of recurrence or metastases 18 months after surgical removal of the lesion.