Impact of Sample Type on D-Dimer Screening.

Background: The quality of laboratory test results depends on various factors, including sample type selection. Blood samples, such as whole blood, plasma and serum are commonly used for most clinical laboratory examinations. D-dimer parameters are frequently analysed in haematology laboratories and serve as biomarkers for coagulation activation and fibrinolysis. This study aimed to assess the impact of using different sample types on the quality of D-dimer test results. Method: An observational analytical method was used. D-dimer examination was performed using the fluorescent lateral flow immunoassay method. The study sample consisted of 26 participants aged between 18 years old and 22 years old who had no blood disorders. Whole blood and ethylenediaminetetraacetic acid (EDTA) plasma samples were used for the examination of D-dimer levels. Results: D-dimer levels in 26 participants using whole blood samples had a mean value of 0.23 mg/L (230 ng/mL), while plasma samples yielded a mean value of 0.14 mg/L (140 ng/mL). D-dimer levels obtained from whole blood samples were higher than plasma samples but remained within the normal range of 0 mg/L-0.5 mg/L (0 ng/mL-500 ng/mL). Conclusion: The results showed that whole blood samples were more practical than plasma samples. Nevertheless, plasma samples gave results within the normal range of D-dimer values.

A Multicenter Retrospective Evaluation of Specialized Laboratory Investigations in the Workup of Pediatric Patients With New-Onset Supraventricular Tachycardia.

INTRODUCTION: Specialized laboratory evaluation of supraventricular tachycardia in children may occur, but the utility is unknown. The study objectives are to assess the type, frequency, and results of specialized laboratory testing performed in pediatric patients presenting with new-onset supraventricular tachycardia. We hypothesized that when specialized laboratory testing occurs (particularly for cardiac failure, toxicologic, inflammatory, and thyroid diseases), the results are generally within normal limits. METHODS: This is a retrospective descriptive study using an electronic health record database (TriNetX, Inc). We collected and evaluated the following data of subjects aged younger than 18 years with a first-time supraventricular tachycardia diagnosis: demographics, diagnostic codes, deaths, and laboratory codes/results (natriuretic peptide B, natriuretic peptide B prohormone N-terminal, troponin I, toxicology testing, inflammatory markers, and thyroid studies). RESULTS: A total of 621 subjects (524 [84.4%] without laboratory testing, 97 [15.6%] with laboratory testing) were included. Thyroid studies (65 [10.5%]) were the most frequent laboratory study performed followed by cardiovascular specific studies (35 [5.6%]), inflammatory markers (21 [3.4%]), and toxicology tests (10 [1.6%]) (P = .002). Obtained laboratory testing was more frequent with older subjects, females, and need for emergency, hospital, and critical care services. DISCUSSION: Cardiac-specific and noncardiac laboratory testing is frequently ordered for pediatric patients who present with supraventricular tachycardia. Thyroid studies were the most common laboratory testing ordered, but abnormal results only occurred in less than a quarter of subjects. These findings may highlight a quality improvement opportunity for emergency nurses and practitioners in the practice of obtaining laboratory tests to better reflect high-value evidence-based care for this vulnerable population.

Preventing overuse of laboratory diagnostics: a case study into diagnosing anaemia in Dutch general practice.

BACKGROUND: More information is often thought to improve medical decision-making, which may lead to test overuse. This study assesses which out of 15 laboratory tests contribute to diagnosing the underlying cause of anaemia by general practitioners (GPs) and determines a potentially more efficient subset of tests for setting the correct diagnosis. METHODS: Logistic regression was performed to determine the impact of individual tests on the (correct) diagnosis. The statistically optimal test subset for diagnosing a (correct) underlying cause of anaemia by GPs was determined using data from a previous survey including cases of real-world anaemia patients. RESULTS: Only 9 (60%) of the laboratory tests, and patient age, contributed significantly to the GPs' ability to diagnose an underlying cause of anaemia (CRP, ESR, ferritin, folic acid, haemoglobin, leukocytes, eGFR/MDRD, reticulocytes and serum iron). Diagnosing the correct underlying cause may require just five (33%) tests (CRP, ferritin, folic acid, MCV and transferrin), and patient age. CONCLUSIONS: In diagnosing the underlying cause of anaemia a subset of five tests has most added value. The real-world impact of using only this subset should be further investigated. As illustrated in this case study, a statistical approach to assessing the added value of tests may reduce test overuse.

The liver fibrosis index is superior to the APRI and FIB-4 for predicting liver fibrosis in chronic hepatitis B patients in China.

BACKGROUND: The purpose of this study was to prospectively investigate the value of real-time ultrasound elastography (RTE) for the diagnosis of liver fibrosis (LF) in patients with chronic hepatitis B (CHB), to correlate the elastography findings with the histologic stage of LF and to compare RTE findings with those from noninvasive tests of LF calculated using laboratory blood parameters. METHODS: Liver biopsies, laboratory blood testing, and RTE were performed in 91 patients with CHB. The LF index (LFI) was calculated using a multiple linear regression equation involving 11 parameters, which represented the degree of LF. The higher the LFI is, the greater the degree of LF. RESULTS: The mean aspartate aminotransferase-to-platelet ratio index (APRI) and the mean fibrosis index based on four factors (FIB-4) were significantly different for the 5 stages of LF, respectively. The APRI (r = 0.43, P = 0.006), FIB-4 (r = 0.51, P = 0.012) and LFI (r = 0.562, P = 0.004) were correlated with the stages of LF. For discriminating stage F0 from F1, only the LFI had significant power (P = 0.026) for predicting stage F1. For discriminating stage F4 from F3, only the LFI had statistically significant power (P = 0.024) in predicting stage F4. The areas under the receiver operating characteristic curves (AUCs) of the LFI for diagnosing significant, advanced LF and liver cirrhosis were significantly higher than those of the APRI and FIB-4, and the LFI had better sensitivity and specificity. CONCLUSIONS: The LFI calculated by RTE is reliable for the assessment of LF in patients with CHB and has better discrimination power than the APRI and FIB-4.

Case report: Experience and insights on the treatment of two cases of cryptococcal meningitis during the later stages of the COVID-19 pandemic.

In the late stages of the COVID-19 pandemic, there's an increasing trend in opportunistic infections, including bacterial and fungal infections. This study discusses the treatment process of two cases of cryptococcal meningitis during the COVID-19 pandemic. It highlights the importance of laboratory testing for these co-infections and stresses the need for vigilance, early diagnosis, and proactive treatment to improve patient outcomes in the post-pandemic era.

Self-Supervised Learning-Based General Laboratory Progress Pretrained Model for Cardiovascular Event Detection.

OBJECTIVE: Leveraging patient data through machine learning techniques in disease care offers a multitude of substantial benefits. Nonetheless, the inherent nature of patient data poses several challenges. Prevalent cases amass substantial longitudinal data owing to their patient volume and consistent follow-ups, however, longitudinal laboratory data are renowned for their irregularity, temporality, absenteeism, and sparsity; In contrast, recruitment for rare or specific cases is often constrained due to their limited patient size and episodic observations. This study employed self-supervised learning (SSL) to pretrain a generalized laboratory progress (GLP) model that captures the overall progression of six common laboratory markers in prevalent cardiovascular cases, with the intention of transferring this knowledge to aid in the detection of specific cardiovascular event. METHODS AND PROCEDURES: GLP implemented a two-stage training approach, leveraging the information embedded within interpolated data and amplify the performance of SSL. After GLP pretraining, it is transferred for target vessel revascularization (TVR) detection. RESULTS: The proposed two-stage training improved the performance of pure SSL, and the transferability of GLP exhibited distinctiveness. After GLP processing, the classification exhibited a notable enhancement, with averaged accuracy rising from 0.63 to 0.90. All evaluated metrics demonstrated substantial superiority ([Formula: see text]) compared to prior GLP processing. CONCLUSION: Our study effectively engages in translational engineering by transferring patient progression of cardiovascular laboratory parameters from one patient group to another, transcending the limitations of data availability. The transferability of disease progression optimized the strategies of examinations and treatments, and improves patient prognosis while using commonly available laboratory parameters. The potential for expanding this approach to encompass other diseases holds great promise. CLINICAL IMPACT: Our study effectively transposes patient progression from one cohort to another, surpassing the constraints of episodic observation. The transferability of disease progression contributed to cardiovascular event assessment.

A multi-year evaluation of medical student performance on and perceptions of collaborative gross anatomy laboratory examinations.

Collaborative testing and its benefits have been reported in diverse disciplines across different types of academic institutions. However, there has been minimal research conducted on collaborative assessments in medical schools, particularly in the gross anatomy laboratory. The objectives of this study were to explore the effect of collaborative anatomy laboratory examinations on student performance and to gauge student perceptions of this assessment format. This study examined five academic years of medical students' performance on a two-stage, collaborative anatomy laboratory examination wherein each student's overall score was a weighted combination of scores from the individual and team examination. Analyses of a descriptive survey capturing students' perceptions of the assessment method were also performed. Individual examination averages increased since implementing the collaborative assessment (p < 0.001), and team examination averages were higher than individual examination averages (p < 0.001). Teams outperformed each of their team members 98% of the time. Teams had a greater than 0.90 incidence of answering a question correctly if more than one person in the group got the answer correct on the individual portion, and a 0.66 incidence of answering correctly if only one person in their group answered correctly on the individual portion. Student feedback identified the discussions and learning that took place during the team portion to be a beneficial feature of this assessment format. Students also reported that this collaborative assessment made them feel a higher level of responsibility to perform well, and that it improved their understanding of gross anatomy.

HIV-specific cytotoxic T-cells in HIV-exposed but uninfected Gambian women.

A crucial requirement in the rational design of a prophylactic vaccine against the human immunodeficiency virus (HIV) is to establish whether or not protective immunity can occur following natural infection. The immune response to HIV infection is characterized by very vigorous HIV-specific cytotoxic T-lymphocyte (CTL) activity. We have identified four HIV-1 and HIV-2 cross-reactive peptide epitopes, presented to CTL from HIV-infected Gambians by HLA-B35 (the most common Gambian class I HLA molecule). These peptides were used to elicit HIV-specific CTLs from three out of six repeatedly exposed but HIV-seronegative female prostitutes with HLA-B35. These women remain seronegative with no evidence of HIV infection by polymerase chain reaction or viral culture. Their CTL activity may represent protective immunity against HIV infection.

PIP: A crucial requirement in the rational design of a prophylactic vaccine against HIV is to establish whether or not protective immunity can occur following natural infection. The immune response to HIV infection is characterized by very vigorous HIV-specific cytotoxic T-lymphocyte (CTL) activity. Four HIV-1 and HIV-2 cross-reactive peptide epitopes were identified, presented to CTL from HIV-infected Gambian women by HLA-B35 (the most common Gambian class 1 HLA molecule). The study population consisted of 20 women: 14 had been prostitutes for more than 5 years and reported little condom usage and 6 were long-term sexual partners of HIV-infected men. Peptide-stimulated cultures were also set up from 8 known seropositive donors with HLA-B35 or B53, and from a control group of volunteers at low-risk of HIV infection with HLA-B35 (12 Gambian and 7 European) and 2 Gambians with HLA-B53. Specific CTL activity against one or more peptides was repeatedly detected after 10-14 days in the peptide-stimulated cultures from 3 of the 6 high-risk seronegative women with HLA-B35, but not in their three counterparts with HLA-B53 nor in any of the low-risk volunteers. The strongest responses were generated toward the HIV-1 pol peptide, which lies close to the active site of reverse transcriptase, and to the nef peptide, which is conserved between HIV-1 and -2. HIV-specific CTL in seronegative subjects could potentially be a response to acute HIV infection, before the development of antibodies, but the women were still seronegative and virus-culture negative 3 months after the CTL were first detected, making recent infection extremely unlikely. These women remain seronegative with no evidence of HIV infection by polymerase chain reaction or viral culture. Their CTL activity may represent protective immunity against HIV infection.

A role for a new herpes virus (KSHV) in different forms of Kaposi's sarcoma.

Kaposi's sarcoma (KS) is a previously rare, tumour-like lesion of controversial biological nature. KS has since the early 1980s become frequent in patients with AIDS, particularly in homosexuals. KS is also endemic in Central Africa predominantly in otherwise healthy men but also in women and children. Recently, evidence for the presence of novel, herpes virus DNA sequences in more than 90% of AIDS Kaposi lesions (AKS) was presented. This DNA was identified using representational difference analysis (RDA) generating short, unique sequences with variable homology to several herpes virus, but no intact virus was recovered. If these DNA-sequences are also present in other, non-HIV-associated forms of Kaposi's sarcoma this would strongly suggest a specific, aetiopathological involvement of this putative new herpes virus in the pathogenesis of Kaposi's sarcoma, rather than a contamination of yet another opportunistic virus in immunosuppressed AIDS patients.

PIP: Samples were examined by polymerase chain reaction (PCR) for the presence of the putative Kaposi's sarcoma herpes virus (KSHV). KS DNA from HIV-negative, African, endemic (EKS) samples, and epidemic HIV-positive KS (AKS), and sporadic KS (SKS) samples were tested from Tanzania and Sweden. All of the HIV KS (18 African EKS and 4 Swedish SKS) as well as the HIV-positive AIDS-related KS (16 African and 7 Swedish AKS) biopsies were shown to contain the previously described DNA sequences. KS lesions from children, females, and males in various tissues were analyzed including skin, lymph nodes, gut and oral mucosa. All forms of KS showed a single PCR product of the expected size (233 base pairs). To exclude amplification of other types of herpes virus, virus preparations of Epstein-Barr virus (EBV), herpes simplex virus, cytomegalovirus, vesicular stomatitis, and human herpes virus type 6 (HHV6) were assayed, again by PCR, using the KSHV primers. No PCR products were obtained with any of these virus strains. However, most HIV-positive and HIV-negative KS DNA samples also contained either EBV and/or HHV6 sequences. All biopsies from non-KS tissues (cells) of HIV-positive and HIV-negative individuals were consistently negative for KSHV by PCR. The observation that the same herpes virus-like DNA sequence is present in endemic and sporadic, as well as AIDS-related, Kaposi's sarcoma cases suggests a possible pathogenic association between this putative novel, herpes-like virus and KS. The herpes virus-like DNA sequences described by Y. Chang in 1994 may indeed represent a novel herpes (KSHV), etiopathologically associated with various clinical forms of Kaposi's sarcoma. Its pathogenic importance is indicated by its presence in different KS tissues with various clinical types of KS and its absence from non-KS-involved tissues. Furthermore, the presence of KSHV in KS of children suggests a nonsexual mode of transmission.

Influence of augmented Hageman factor (Factor XII) titers on the cryoactivation of plasma prorenin in women using oral contraceptive agents.

Prolonged cold storage of plasma may induce the conversion of plasma prorenin (inactive renin) to renin. This phenomenon is exaggerated in oral contraceptive (OC) users; the titer of Hageman factor (HF, Factor XII) in OC users is higher than in nonusers. The present study relates these observations. The increment in plasma renin activity (PRA) during cold storage, as measured by generation of angiotensin I, correlated strongly with the initial plasma titer of HF. Increasing the HF titer of nonusers to that observed in OC users by addition of purified HF increased cold-induced PRA at least twofold, while reducing the plasma HF titer of OC users correspondingly decreased cold-induced PRA. Thus, in OC users, the enhanced conversion of plasma prorenin to renin during cold storage reflects the elevated plasma titer of HF.

PIP: Prolonged cold storage of plasma may induce the conversion of plasma prorenin (inactive renin) to renin. This phenomenon is exaggerated in oral contraceptive (OC) users; the titer of Hageman factor (HF, Factor 12) in OC users is higher than in nonusers. The present study relates these observations. The increment in plasma renin activity (PRA) during cold storage, as measured by generation of angiotensin I, correlated strongly with the initial plasma titer of HF. Increasing the HF titer of nonusers to that observed in OC users by the addition of purified HF increased cold-induced PRA at least 2-fold, while reducing the plasma HF titer of OC users correspondingly decreased cold-induced PRA. Thus, in OC users, the enhanced conversion of plasma prorenin to renin during cold storage reflects the elevated plasma titer of HF.

Sperm-related antigens, antibodies, and circulating immune complexes in sera of recently vasectomized men.

Sera from 35 men were collected before and at timed intervals subsequent to vasectomy and examined for the presence of (a) antibody reactive with human spermatozoa, (b) sperm-related antigen, and (c) circulating immune complexes (CIC). Fewer than 10% of the men examined were ever positive for antisperm antibodies. However, sperm-related antigens were elevated in the sera of 18, 18, and 26% of the mean at 2 wk, 2 mo, and 4 mo postvasectomy, respectively. CIC were detected in the sera of some vasectomized men by three different assays. The CIC in patients' sera were precipitated with polyethylene glycol, dissociated, and the individual CIC components identified by an enzyme-linked immunosorbent assay. Most, but not all, of the CIC contained antigen reactive with antisperm immunoglobulin (Ig)G and some also contained complement components C3 and/or Clq. IgA was identified in some of the CIC positive for IgG and sperm antigen and two men had IgM-containing CIC. Analysis of the CIC by sucrose gradient centrifugation revealed them to be heterogeneous in size.

Long-term vasectomy: effects on the occurrence and extent of atherosclerosis in rhesus monkeys.

We demonstrated previously that atherosclerosis develops more extensively in vasectomized cynomolgus macaques fed an atherogenic diet and speculated that the immunologic response to sperm antigens may have exacerbated the atherosclerosis. We report here that rhesus monkeys vasectomized for 9-14 yr and fed monkey chow (devoid of cholesterol and low in fat) rather than an atherogenic diet also had more extensive and severe atherosclerosis than did control animals of the same age. The extent of atherosclerosis was considered as the percentage of intimal surface with plaques. No control animals were found to have plaques in the thoracic aorta, but 7 of 10 vasectomized monkeys were affected. The plaques in the vasectomized monkeys occupied about 13% of the intimal surface. In 4 of 7 control monkeys and 7 of 10 vasectomized monkeys there were lesions in the abdominal aortas; the lesions were considerably more extensive and severe in the vasectomized animals. Lesions were also more common in iliac arteries of vasectomized animals, and the extent was increased about threefold. Plaques were seen at the carotid bifurcation in all of the animals of both the control and vasectomized groups. The carotid bifurcation plaques of the vasectomized monkeys were larger than those of the control animals on the right but not on the left side. Histologically, the lesions of vasectomized monkeys did not appear to be qualitatively different from those of control animals, even though they were larger and contained more collagen, lipid, and mucopolysaccharides. Grossly, the distribution of the lesions in the vasectomized animals was different from that in the control animals, and that of lesions induced by atherogenic diets, i.e., the lesions were distributed randomly within the artery rather than around bifurcations. More extensive atherosclerosis was noted among vasectomized animals that were found to lack demonstrable circulating free antisperm antibodies. On the basis of the observations made in this study, we suggest that the antisperm antibodies that form after vasectomy may result in circulating immune complexes that exacerbate atherosclerosis.

Descripción de las características sociodemográficas y clínicas de pacientes con litiasis renal

Contexto: los cálculos renales son cúmulos o depósitos de minerales que se forman en los cálices, la pelvis renal o el tracto urinario. Objetivo: describir las características sociodemográficas y clínicas de una muestra de pacientes con litiasis renal, mayores de 18 años. Metodología: estudio observacional descriptivo de pacientes atendidos en una consulta ambulatoria de Nefrología en Manizales en el periodo 2010-2020, donde se contaba con estudios en sangre, orina de 24 horas y estudio fisicoquímico del cálculo, además de datos sociodemográficos y clínicos relacionados. Se fragmentaron en grupos, de acuerdo con los hallazgos encontrados en los cálculos disponibles, dividiéndose en oxalato de calcio en su totalidad, calcio mixto con otro compuesto y el último grupo de cálculo no calcio. Resultados: se identificaron 54 pacientes con nefrolitiasis, de los cuales 14 de ellos fueron excluidos. Finalmente, 40 pacientes cumplieron con los criterios de inclusión. La mediana de edad fue 52,5 años, predominio del sexo masculino (55 %), donde se encontró en 20,5 % hiperuricemia, hipercalcemia en 17,6 %, hiperfosfatemia en 5 % e hipercaliemia en 7,5 %. En orina se encontró: hipocitraturia en el 71,1 %, seguido de hipercalciuria (12,5 %), hiperuricosuria (10 %) e hiperoxaluria (5 %). En 17 de los pacientes (42,5 %) se logró el estudio de la composición fisicoquímica del cálculo, en ellos la variedad de calcio mixto fue la más frecuente (55,5 %). Conclusiones: este estudio describe las características de pacientes con cálculos renales, mostrando que la mayoría tiene alteraciones metabólicas asociadas a nefrolitiasis, siendo la hipocitraturia el hallazgo más frecuente y que la mayoría de los cálculos tiene calcio en su composición.

Background: Kidney stones are accumulations or mineral deposits that form in the calyces, renal pelvis, or urinary tract. Purpose: To describe the sociodemographic and clinical characteristics of a sample of patients with kidney stones over 18 years of age. Methodology: Descriptive observational study. Patients treated in an outpatient nephrology and urology consultation in Manizales during the years 2010 to 2020, in which there were studies in blood, 24-hour urine, and a physicochemical study of the stone, as well as related sociodemographic and clinical data. They were divided into groups, according to the findings found in the available stones, dividing into calcium oxalate in its entirety, calcium mixed with another compound and the last group of non-calcium stone. Results: 54 patients with nephrolithiasis were identified, 14 of them were excluded. Finally, 40 patients met the inclusion criteria. Median age was 52.5 years, male predominance (55%), hyperuricemia was found in 20.5%, hypercalcemia in 17.6%, hyperphosphatemia in 5% and hyperkalemia in 7.5%. In urine, hypocitraturia was found in 71.1%, followed by hypercalciuria (12.5%), hyperuricosuria (10%), and hyperoxaluria (5%). In 17 patients (42.5%) there was a result of the physicochemical composition of the stone, in them the mixed calcium variety was the most frequent (55.5%). Conclusions: This study describes the characteristics of patients with kidney stones, showing that the majority have metabolic alterations associated with nephrolithiasis, hypocitraturia being the most frequent finding, and that most stones have calcium in their composition.

Mammary tumorigenesis in chemical carcinogen-treated mice. VII. Prolactin and progesterone levels in BALB/c mice.

PIP: Pituitary and serum levels of prolactin (PRL) and serum levels of progesterone (P) were determined by polyacrylamide gel electrophoresis and radioimmunoassays in BALB/c female mice, 15-17 or 44 weeks old, treated with chemical carcinogens. Neither 1.5 mg 3-methylcholanthrene (MCA) nor 1.5-6 mg 7,12-dimethylbenz(a)anthracene (DMBA) markedly altered pituitary or serum levels of PRL in the younger mice, though DMBA increased the total pituitary content of PRL by about 33% in the 44-week-old mice. However, this increase was not correlated with the incidence of mammary tumors in the group or individuals. MCA increased serum P levels by about 22% within 50 days of the last treatment. This increase was attributable to higher serum levels of P during the diestrous and proestrous phases of the cycle. Adrenalectomy reduced serum P levels by about 60%, wheras ovariectomy had no effect. Serum P levels in 44-week-old rats were not affected by DMBA. The results fail to support the notion that MCA and DMBA promote murine mammary tumorigenesis by increasing pituitary and serum prolactin concentrations.^ieng

Determinants of genital human papillomavirus infection in young women.

Carcinoma of the cervix has several well-established epidemiologic risk factors, including multiple sexual partners and early age at first intercourse. Human papillomavirus (HPV) infection appears to have an etiologic role in the development of cervical neoplasia, but evidence linking HPV infection to known risk factors for cervical cancer has been inconsistent. The lack of expected correlations may be due to the inaccuracy of HPV assays previously used. A polymerase chain reaction DNA amplification method for the detection of HPV was used to investigate the determinants of genital HPV infection in a cross-sectional sample of 467 women attending a university health service. In contrast to studies using less accurate detection methods, the risk factors for HPV infection found here were consistent with those for cervical neoplasia. The risk of HPV infection was strongly and independently associated with increasing numbers of sexual partners in a lifetime, use of oral contraceptives, younger age, and black race. Age at first intercourse, smoking, and history of a prior sexually transmitted disease were correlated with, but not independently predictive of, HPV infection. These results demonstrate that the key risk factors for cervical carcinoma are strongly associated with genital HPV infection. This correlation suggests that HPV has an etiologic role in cervical neoplasia and reaffirms the sexual route of HPV transmission.

Invasive cervical cancer and smoking in Latin America.

A case-control study of 667 patients with invasive squamous cell carcinoma of the cervix and 1,430 controls from four Latin American countries showed an age-adjusted relative risk (RR) of 1.2 [95% confidence interval (CI) = 1.0-1.4] for women who had ever smoked, with risk rising to 1.7 (95% CI, 0.8-3.6) for women who smoked greater than or equal to 30 cigarettes per day. The associations were practically eliminated after adjustment for the number of sexual partners and alcohol consumption, probably a surrogate for an unidentified life-style risk factor. Some excess risk persisted among women who smoked for extended periods (RR = 1.5 for greater than or equal to 40 yr), as well as those who began smoking at older ages (RR = 1.7 for greater than 30 yr), which suggests a late-stage effect. In addition, among women who tested positive for human papillomavirus (HPV) type 16 or 18 by filter in situ hybridization, there was an increased risk for women who had ever smoked and a dose-response relationship with the number of cigarettes smoked (adjusted RRs compared with HPV-negative nonsmokers = 5.0 for HPV-positive nonsmokers, 5.5 for less than 10 cigarettes/day, and 8.4 for greater than or equal to 10 cigarettes/day). In contrast, HPV-negative women had no increased risk associated with smoking. These results, from a high-incidence area where intensive smoking among women is still relatively rare, suggest that smoking has a limited effect on cervical cancer risk, possibly only among women with specific types of HPV.

Her-2/neu and INT2 proto-oncogene amplification in malignant breast tumors in relation to reproductive factors and exposure to exogenous hormones.

In previous studies in southern Sweden, early use of oral contraceptives has been found to be accompanied by an increased risk of developing premenopausal breast cancer, and the tumors developing in these patients have shown a more aggressive behavior. In the present study, amplification of the proto-oncogenes Her-2/neu (also known as ERBB2) and INT2 was studied in primary tumor specimens from 72 premenopausal women and was related to starting age of oral contraceptive use and other reproductive risk factors. Amplification of Her-2/neu was more common among early oral contraceptive users (i.e., those starting at less than or equal to 20 years of age) than among nonusers or late users (odds ratio [OR], 5.3; 95% confidence interval [CI], 1.6-16.7), whereas INT2 amplification did not differ significantly among those groups (OR, 0.9; 95% CI, 0.1-5.0). The likelihood of INT2 amplification was greater among users of progestins and those with a history of abortions before the first full-term pregnancy (OR, 9.0; 95% CI, 1.3-51.7; and OR, 18.6; 95% CI, 2.2-165.8, respectively). No significant relationships were found between proto-oncogene amplification and the variables of parity, age at first full-term pregnancy, or late abortion. The increased ORs persisted after adjustment for age at diagnosis and other risk factors. The findings suggest that the higher rate of Her-2/neu amplification among early oral contraceptive users is an effect of the oral contraceptive use per se rather than of the relative youth of the users. Moreover, the relationship between progestin use and early abortion and amplification of the INT2 gene is biologically plausible.

Potent inhibitory effect of a new antiestrogen (RU 16117) on the growth of 7,12-dimethylbenz[a]anthracene-induced rat mammary tumors.

At the daily dose of 24 mug for a period of 4 weeks, RU 16117 (11alpha-methoxyethinyl estradiol), a new antiestrogen, led to 65% reduction of the number of already established dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in female Sprague-Dawley rats. Not only the tumor number but also the tumor size was reduced by RU 16117 in a manner similar to that seen after ovariectomy. The absence of an inhibitory effect of doses of 0.1 to 12.5 mug 17beta-estradiol (E2) per day, a dose-range which covers the low estrogenic activity of the RU 16117 doses used, suggested that the inhibitory effect of RU 16117 was not due to its estrogenic activity. Decreased levels of receptors for E2, progesterone, and prolactin were found in the tumors remaining after ovariectomy; treatment with the dose of RU 16117 sufficient to inhibit tumor growth (24 mug) had a similar inhibitory effect on the levels of E2 and prolactin receptors. These data suggested that a reduction of hormone receptor levels in the tumor tissue could be a mechanism by which RU 16117 acts as a potent inhibitor of the growth of DMBA-induced mammary carcinoma.

PIP: The new antiestrogen RU 16117, at doses of 8 or 24 mcg daily, had been shown to completely prevent the development of rat mammary cancer when given from the day after 7,12-dimethylbenz(a)anthracene (DMBA) administration. This study was undertaken to investigate the effect of this compound on the growth of DMBA-induced tumors which had already developed in Sprague-Dawley rats. The effect was compared with that of castration. Levels of receptors for 17beta-estradiol (E2), progesterone, and prolactin (PRL) were correlated with the response. At about 3 months after DMBA administration animals with palpable tumors were selected. The rats were then treated daily for 4 weeks with .1, .5, 2.5, or 12.5 mcg E2 or with 2, 8, or 24 mcg RU 16117 injected in .1 ml of 1% gelatin in .9% NaCl. Controls were injected with the vehicle alone. For comparison, a group of rats were ovariectomized. After 4 weeks' treatment rats were killed, blood collected, and a cytosol was prepared from tumor tissues. Binding assays and radioimmunoassays were done. 8 and 24 mcg doses of RU 16117 led to 45 and 65% inhibition of tumor number, respectively, and tumor size was markedly reduced. Lower doses had less effect. Ovariectomy had an effect similar to that of 24 mcg RU 16117. E2 doses did not change the number or size of tumors. Decreased levels of receptors for E2, progesterone, and PRL were found in the tumors remaining after ovariectomy. The 24 mcg dose of RU 16117 had a similar effect on levels of E2 and PRL receptors. It was considered likely that RU 16117 exerts its inhibitory activity at both the hypothalamic-pituitary and tumor levels.

Effects of progesterone on the response to epidermal growth factor and other growth factors in cultured human meningioma cells.

The presence of receptors for progesterone in a large proportion of human meningioma tissues is well established. The occurrence of increased rates of growth of meningiomas in situ during pregnancy suggests the existence of a relationship between high progesterone levels and the growth of meningiomas. However, experiments with cultured meningioma tissue (cells or explants) have shown only minimal effects of progesterone. It has been shown recently that many meningiomas have receptors for epidermal growth factor. In this paper we have investigated the response of cultured human meningioma cells to epidermal growth factor and other growth factors and the modulation of this response by progesterone and the progesterone-receptor blocking agent mifepristone (RU 38486). The results suggest that the presence of progesterone in the culture medium increases the sensitivity of meningioma cells to mitogenic stimuli, whereas mifepristone can counteract the stimulating effects of progesterone.