Is maternal smoking during pregnancy a causal environmental risk factor for adolescent antisocial behavior? Testing etiological theories and assumptions.

BACKGROUND: Although many studies indicate that maternal smoking during pregnancy (SDP) is correlated with later offspring antisocial behavior (ASB), recent quasi-experimental studies suggest that background familial factors confound the association. The present study sought to test alternative etiological hypotheses using multiple indices of adolescent ASB, comparing differentially exposed siblings, and testing assumptions in the sibling-comparison design. METHOD: The study examined the association between maternal SDP and adolescent-reported ASB, criminal convictions and membership in a group of individuals with early-starting and chronic ASB among 6066 offspring of women from the National Longitudinal Survey of Youth, a representative sample of women in the USA. The analyses controlled for statistical covariates and examined associations while comparing differentially exposed siblings. RESULTS: At the population level, each additional pack of cigarettes per day predicted greater mean adolescent-reported ASB symptoms [ratio of means 1.15, 95% confidence interval (CI) 1.08-1.22], odds of being in the top 10% of ASB [odds ratio (OR) 1.34, 95% CI 1.10-1.65], hazard of a criminal conviction [hazard ratio (HR) 1.51, 95% CI 1.34-1.68] and odds of chronic ASB (OR 1.57, 95% CI 1.25-1.99). SDP robustly predicted most assessments of ASB while controlling for measured covariates. When siblings exposed to differing levels of SDP were compared, however, all of the associations were attenuated and were not statistically significant: adolescent-reported mean ASB (ratio of means 0.86, 95% CI 0.74-1.01), high ASB (OR 0.67, 95% CI 0.41-1.12), criminal conviction (HR 0.98, 95% CI 0.66-1.44) and chronic ASB (OR 0.80, 95% CI 0.46-1.38). CONCLUSIONS: The results strongly suggest that familial factors account for the correlation between SDP and offspring adolescent ASB, rather than a putative causal environmental influence of SDP.

Addition of constitutive c-myc expression to Abelson murine leukemia virus changes the phenotype of the cells transformed by the virus from pre-B-cell lymphomas to plasmacytomas.

Abelson murine leukemia virus (A-MuLV), a retrovirus that expresses the v-abl oncogene, characteristically induces pre-B-cell lymphomas following in vivo infection of BALB/c mice or in vitro infection of suspensions of fetal liver or bone marrow cells. ABL-MYC, a retrovirus that expresses both v-abl and c-myc, induces solely plasmacytomas in BALB/c mice. To investigate how the addition of overexpression of c-myc to that of v-abl accomplishes this dramatic change in the phenotype of the cells transformed by these closely related retroviruses, we utilized helper-free A-MuLV (psi 2) and ABL-MYC (psi 2) in vitro to infect suspensions of cells from different lymphoid tissues and purified immature and purified mature B cells. As expected, A-MuLV(psi 2) induced only pre-B-cell lymphomas in vivo and in vitro when immature B cells were present. ABL-MYC(psi 2), on the other hand, produced only plasmacytomas, even when purified immature B lymphocytes were infected in vitro. Although the A-MuLV(psi 2)-induced pre-B-cell lymphomas express easily detectable levels of c-myc mRNA, maturation into more-mature forms of B lymphocytes is blocked. The constitutively overexpressed c-myc in the ABL-MYC retrovirus abrogates this block, permits maturation of infected immature B cells, and yields transformed plasma cells.

Expression of c-cbl proto-oncogene is modulated during differentiation but not during induction of proliferation.

The proto-oncogene c-cbl is expressed as two mRNAs, ca. 10.5 and 3.1 kb, both of which appear to be functional inasmuch as both can be found on polyribosomes in tissues that express both mRNAs. The function of the 120 kDa c-cbl protein is not known, but its primary structure resembles that of a DNA-binding transcription factor with a basic region, a nuclear localization sequence, a zinc finger-like motif and a leucine zipper. To test whether expression of this protein resembles that of regulatory proteins, we studied expression of c-cbl mRNA and protein in differentiating cells and in proliferating cells, conditions in which expression of regulatory proteins commonly is modulated. Differentiation of both erythroleukemia cells and teratocarcinoma cells showed a decrease in c-cbl expression, with kinetics similar to those of transcription factors that are immediate early response genes. Unlike early response genes, however, c-cbl mRNA showed a very long half life in B lymphocytes. Further, in fibroblasts and spleen cells that were induced to proliferate, c-cbl mRNA expression did not change, and expression of c-cbl protein did not change during any stage of the cell cycle. These characteristics indicate that c-cbl does not belong to the immediate early response type of transcription factor. Yet when c-cbl is truncated, as in v-cbl, the protein does enter the nucleus and bind DNA, and it contributes to neoplastic transformation of B lymphocytes and fibroblasts. These findings indicate that the regulation of the c-cbl proto-oncogene is different from that of the proto-oncogenes identified to date and suggest that c-cbl belongs to a new class of proto-oncogenes.

The catalytic domain of PKC-epsilon, in reciprocal PKC-delta and -epsilon chimeras, is responsible for conferring tumorgenicity to NIH3T3 cells, whereas both regulatory and catalytic domains of PKC-epsilon contribute to in vitro transformation.

Protein kinase C-epsilon (PKC-epsilon) has been shown to increase growth and cause malignant transformation when overexpressed in NIH3T3 cells, whereas PKC-delta reduced fibroblast growth. Two reciprocal chimeric proteins (PKC-epsilondelta and PKC-deltaepsilon were constructed by exchanging the regulatory and catalytic domains of PKC-delta and -epsilon and were stably overexpressed in NIH3T3 cells. Fibroblasts that overexpressed either chimera showed maximum cell density and morphology that were intermediate between cells overexpressing PKC-delta and those that overexpressed PKC-epsilon. Moreover, all lines that expressed chimeras were capable of anchorage-independent growth in the presence of TPA, which indicated that both the regulatory and catalytic domains of PKC-epsilon could independently induce NIH3T3 transformation, although the combination of both domains, as found in PKC-epsilon, was the most active form. In contrast, the translocation pattern and ability to induce tumors in nude mice was attributable to the catalytic domains exclusively. In particular, cells that expressed PKC-deltaepsilon retained PKC-epsilon's full potency of tumorgenicity when injected into nude mice. In sum, our findings not only reinforce the concept that only certain PKC isozymes contribute to carcinogenesis but also show that different domains of PKCs mediate the physiologically distinguishable events of transformation and tumorgenesis.

Adjuvant chemotherapy for osteosarcoma: a randomized prospective trial.

To determine the role of chemotherapy in the multidisciplinary treatment of patients with osteosarcoma, a randomized prospective trial of postoperative adjuvant chemotherapy was begun in 1981. Fifty-nine patients with nonmetastatic classic intramedullary osteosarcoma were randomized; 32 received postoperative adjuvant chemotherapy consisting of high-dose methotrexate, Adriamycin (Adria Laboratories, Columbus, OH), and BCD (bleomycin, cytoxan, actinomycin D), and 27 patients received no adjuvant chemotherapy. At a median follow-up of 2 years, there was a statistically significant improvement in both disease-free and overall survival in those who received adjuvant chemotherapy. In addition, there was no difference in the less than 20% disease-free or overall survival of patients treated in the 1970s who did not receive chemotherapy, as compared with the concurrent nontreatment controls. Therefore, with identical staging procedures, uniform surgical management, and standard pathologic evaluation, postoperative adjuvant chemotherapy definitely improves disease-free and overall survival in patients with osteosarcoma.

The cDNA sequence, expression pattern and protein characteristics of mouse protein kinase C-zeta.

A 2199-bp complementary DNA (cDNA) that encodes protein kinase C-zeta (PKC-zeta) has been isolated from mouse brain by a combination of reverse transcription and primer extension. The predicted PKC-zeta protein consists of 592 amino acids which are 99% identical to those of rat PKC-zeta. Northern blots that were probed with this cDNA revealed abundant 2200-nucleotide (nt) and 4200-nt PKC-zeta mRNAs in mouse brain in roughly equal amounts. PKC-zeta mRNA was also abundant in normal lung, kidney, and testes, and in several hemopoietic tumor lines. In all other mouse tissues and cell lines that were examined, at least faint levels of PKC-zeta mRNAs could also be detected. In tissues other than brain, the amount of PKC-zeta mRNA was less, and the smaller species generally predominated. Furthermore, in these tissues, both PKC-zeta mRNAs appear to be approximately 200 nt longer than the two mRNAs found in the brain. When the cDNA is expressed in insect cells via a baculovirus expression vector, a 75-kDa protein is synthesized which, unlike other PKC isoforms, does not bind phorbol ester, even at very high concentrations.

A protein kinase-encoding gene, pkt1, from Trichoderma reesei, homologous to the yeast YPK1 and YPK2 (YKR2) genes.

A gene (pkt1) was isolated from the filamentous fungus Trichoderma reesei, which exhibits high homology with the yeast YPK1 and YKR2 (YPK2) genes. It contains a 2123-bp ORF that is interrupted by two introns, and it encodes a 662-amino-acid protein with a calculated M(r) of 72,820. During active growth, pkt1 is expressed as two mRNAs of 3.1 and 2.8 kb which differ in the 3' untranslated region due to the use of two different polyadenylation sites.

Identification of the primary growth response gene, ST2/T1, as a gene whose expression is differentially regulated by different protein kinase C isozymes.

Individual protein kinase C isozymes have been shown to play different roles in mediating proliferation, differentiation and transformation, but it is not known to what extent these effects involve induction of expression of particular genes. To explore the differential gene expression that might be induced by activation of different PKC isozymes, we stably transfected NIH 3T3 cells with expression vectors that encode the isozymes PKC-alpha, -beta II, -gamma, -delta, -epsilon, -sigma and -eta. Using differential display-reverse transcription-polymerase chain reaction we isolated a small cDNA that encodes a portion of the primary response gene, ST2 (also referred to as T1 or DER4), and we confirmed by RNA blot studies that ST2/T1 expression is differentially regulated by PKC isozymes. ST2/T1 mRNA is undetectable in the unstimulated parental NIH 3T3 cells that express only the alpha isozyme of PKC, but it can be induced by phorbol ester treatment. Clones that overexpress PKC-alpha, -delta or -epsilon similarly do not express ST2/T1 until they are stimulated with phorbol esters, which induces expression of ST2/T1 with kinetics similar to wild-type NIH 3T3 but to different extents. In contrast, ST2/T1 mRNA is already present in unstimulated cells that overexpress PKC-beta II, -gamma, -sigma and -eta, but phorbol ester greatly enhances ST2/T1 expression in these cells. These results suggest a differential role for PKC isozymes in mediating the ST2/T1 expression that is induced by growth stimuli.

Unique expression pattern of protein kinase C-theta: high mRNA levels in normal mouse testes and in T-lymphocytic cells and neoplasms.

A 2.2-kb cDNA that contains the entire coding region of mouse protein kinase C-theta (PKC-theta) was cloned from skeletal muscle mRNA using reverse transcription and the polymerase chain reaction (PCR). This clone was used as a probe to study the expression of this PKC isoform in normal and transformed hemopoietic cells and other normal tissues. By far the highest steady-state level of PKC-theta mRNA was found as a 2.8-kb transcript on a Northern blot of poly(A)+ RNA from testes. High levels were also found in skeletal muscle, spleen, T lymphomas and purified normal T lymphocytes, but these tissues and cells expressed two transcripts, 3.3 kb and 3.8 kb. Lower levels of similar size transcripts were found in normal brain, B lymphocytes and B-lymphocytic tumors and cell lines.

Induction of plasmacytomas that secrete monoclonal anti-peptide antibodies by retroviral transformation.

ABL-MYC, a retrovirus that coexpresses v-abl and c-myc, was used to infect six BALB/c mice that had been immunized twice with a KLH-conjugated peptide that consisted of the 18 carboxyterminal amino acids of protein kinase C-eta (PKC-eta). All mice developed transplantable, monoclonal plasmacytomas, and five out of six plasmacytomas secreted antigen-specific antibodies, even after transplantation. All these antibodies recognized PKC-eta on Western blots of crude cell lysates and did not cross react with other isoforms of the PKC family.

Identification of unsuspected thyroid carcinoma using immunoperoxidase for thyroglobulin.

Two patients with poorly differentiated metastatic cancer were shown to have metastatic thyroid carcinoma. Each patient had poorly differentiated cancer and remaining thyroid tissue in the neck. The diagnosis was secured using the immunoperoxidase technique with an antibody against thyroglobulin. The proper evaluation of patients with carcinoma of unknown primary involves specific tissue identification using special techniques in pathology.

Serum-blocking factors versus specific cellular tolerance in long-term survival of rat heart allografts.

Long-term survival of Ag-B compatible rat heart allografts was obtained by short-term treatment of the recipients with antilymphocytic serum (ALS). Graft survival apparently was based on a specific change in the hosts rather than on persistent nonspecific effects of ALS. The hosts were not fully tolerant in that they were able to reject secondary skin allografts from the heart donor strain, although in a delayed fashion. The long-surviving heart allografts retained their immunogenicity as they were rejected when retransplanted to new hosts. The passive transfer of serum from long-term heart graft acceptors to new hosts receiving fresh allografts delayed rejection by several days. This effect was seen only with the serum from long-term acceptors suggesting that serum-blocking factors were involved in long-term survival of the heart allografts. However, the ability of adoptively transferred lymphoid cells to break tolerance to a heart allograft residing in a classically tolerant host was tested. In contrast to normal lymphoid cells, cells from the long-term acceptors were unable to break tolerance, suggesting that a specific cellular tolerance had been induced in this cell population. Moreover, a serum from the long-term acceptors failed to block the breakage of tolerance by normal lymphoid cells.

Alternative splicing of pvt-1 transcripts in murine lymphocytic-B neoplasms accompanies amplification and chromosomal translocation.

The Pvt-1 region lies approximately 260 kb 3' of the c-myc proto-oncogene on mouse chromosome 15. Chromosomal translocation or viral integration into the region of Pvt-1 in B-cell or T-cell neoplasms appears to up-regulate c-myc expression by some unknown mechanism. Recent isolations of Pvt-1-encoding cDNAs from both mouse and human tissues indicate that transcripts of Pvt-1 can be found in multiple forms. To elucidate the nature of these transcripts in the mouse, we have analyzed cDNAs from AJ9, an immortalized Ly-1+ B-lymphocytic cell line in which myc/Pvt-1 have been co-amplified, and from ABPC20, a plasmacytoma that contains a t(6;15) translocation in the region of Pvt-1. Alternatively spliced transcripts of Pvt-1 are evident, but a stretch of 57 bp makes up the amino-terminus in each of these cDNAs. This region, designated Pvt-1a, is part of exon 1 and is also found within a 140 aa open reading frame (ORF), the longest Pvt-1 ORF established to date. Pvt-1a also shows homology at the amino acid level with two enzymes associated with transport in E. coli, glutamine permease operon protein glnQ and glycerophosphoryl diester phosphodiesterase glpQ. We predict that such chimeric mRNAs generated in mouse B-cell lymphomas and plasmacytomas with amplified or translocated Pvt-1 sequences may encode an in-frame segment of Pvt-1a.

Discontinuance of immunosuprression in renal transplant patients.

Immunosuppressive therapy was discontinued in six patients for an average of 27 months. In these six patients, only two rejections have occurred. A survey of other transplant centers showed that in such patients rejection was often delayed weeks or months after therapy was stopped. Once immunosuppressive therapy has been stopped, for whatever reason, and rejection has not occurred, consideration should be given to not resuming therapy unless signs of rejection appear.

Composite tissue transfer in limb-salvage surgery.

After extensive resection due to extremity sarcoma, the inability to cover the defect for satisfactory healing and limb function has been an indication for amputation rather than limb salvage. We report herein our experience with seven limb-salvage cases in which we closed difficult and complex defects with composite tissue transfers utilizing microvascular techniques. Free-flap transfers were used to cover soft-tissue defects after extensive resection of primary and locally recurrent tumor and to manage radiation-induced complications. The grafts healed well when infected irradiated tissue was covered, and the grafts tolerated postoperative irradiation. Composite tissue transfer also provided soft-tissue coverage around distal joints that would not have been adequately protected with a skin graft. Complications were minimal, and all patients maintained good extremity function. No patient who underwent composite tissue transfer has had a local recurrence. A free-flap composite tissue transfer can extend the indications for limb-salvage surgery and offers an alternative to amputation in selected patients.

Childbearing and child care in surgery.

HYPOTHESIS: The responsibility for childbearing and child care has a major effect on general surgical residency and subsequent surgical practice. METHODS: A survey of all graduates from a university general surgical training program between 1989 and 2000. RESULTS: Twenty-seven women and 44 men completed general surgical training at our university during the period, and 42 (59%) responded to our survey. The age at completion of the residency was 34.0 +/- 2.2 years for men and 33.9 +/- 2.8 years for women. During residency, 64% (14/22) of the men and 15% (3/20) of the women had children. At the time of the survey, 21 (95%) of the men and 8 (40%) of the women had children. Most residents (24 [57%] of 42) relied on their spouse for child care. During surgical practice, 18 (43%) indicated that they rely on their spouse; 19 (45%) use day care, home care, or both; and (8%) of 26 are unsatisfied with their current child care arrangement. During training, 38% (5/13) of men and 67% (2/3) of women took time off for maternity leave, paternity leave, or child care. Two of 3 surgeons would like to have had more time off during residency; most men (70%, or 7 of 10) recommended a leave of 1 to 3 months, and all women preferred a 3-month maternity or child care leave of absence. During surgical practice, only 12% (2/17) of men but 64% (7/11) of women have taken time off for either childbearing or child care. Half of the respondents (21/42) have a formal leave of absence policy at work, 52% (11/21) of which are paid leave programs. Although the workweek of our practicing graduates is 69 +/- 16 hours for men and 64 +/- 12 hours for women, 62% (26/42) spend more than 20 hours per week parenting. More than 80% (27/32) would consider a part-time surgical practice for more parenting involvement; one third of the responders suggested that 30 hours a week constitutes a reasonable part-time practice, one third preferred fewer than 30 hours, and one third favored more than 30 hours per week. Data are presented as mean +/- SD. CONCLUSIONS: Childbearing and child care may have an enormous impact on one's decision to pursue a career in surgery. To attract and retain the best candidates for future surgeons, formal policies on the availability of child care services in the residency program and the workplace should be studied and implemented. Furthermore, national studies are needed to define appropriate, acceptable workweeks for part-time or flexible practices and the duration of leaves of absence for childbearing or child care.

Bedside noninvasive detection of acute pulmonary embolism in critically ill surgical patients.

HYPOTHESIS: We hypothesized that late pulmonary dead space fraction (Fd(late)) would be a useful tool to screen for pulmonary embolism (PE) in a group of surgical patients, including patients who required mechanical ventilation and patients with adult respiratory distress syndrome. DESIGN: We prospectively calculated Fd(late) in patients with suspected PE who underwent pulmonary angiography. SETTING: University-based, level I trauma center. MAIN OUTCOME MEASURE: Ability of Fd(late) to identify patients with PE. RESULTS: Twelve patients had 14 angiograms for suspected PE. The Fd(late) was 0.12 or above in all 5 patients who had PE; 4 required mechanical ventilation. The Fd(late) values were below 0.12 in 8 of 9 patients without PE. Four patients had adult respiratory distress syndrome. The Fd(late) had 100% sensitivity and 89% specificity for the detection of PE. CONCLUSIONS: The Fd(late) is a valuable tool for bedside screening of PE in surgical patients. We were able to accurately detect all PEs.

Resident experience and opinions about physician-assisted death for cancer patients.

HYPOTHESIS: Surgical residents and staff oncologists (surgical, medical, and radiation therapy) have similar opinions on participation in physician-assisted death for patients with terminal cancer. DESIGN: Prospective survey. SETTING: Tertiary care referral center. PARTICIPANTS: Residents undergoing surgical training (n = 56) and faculty oncologists (n = 24) of all specialties (surgical, medical, and radiation therapy). MAIN OUTCOME MEASURES: Subjects were queried regarding previous experience and willingness to participate (either directly or indirectly) in assisted death for terminal cancer patients. RESULTS: Response rates were 39% (22 of 56) for the residents and 87% (21 of 24) for the oncologists. Of those who responded, 86% (19 of 22) of the residents would aid any of the hypothetical patients with assisted death, whereas only 19% (4 of 21) of the staff oncologists expressed willingness to perform the same service. Furthermore, 32% (7 of 22) of the residents reported previous involvement in a case of assisted death from any disease, whereas only 19% (4 of 21) of the staff oncologists reported previous direct experience with assisted death in the terminal cancer patient. CONCLUSIONS: Surgical residents tend to have more experience with assisted death and are much more willing than staff oncologists to aid terminal cancer patients with this procedure. These opinions and practices are probably not the result of medical education but are developed from personal values.

Cost-benefit analysis of biopsy methods for suspicious mammographic lesions; discussion 994-5.

HYPOTHESIS: Stereotactic core biopsy (SCB) is more cost-effective than needle-localized biopsy (NLB) for evaluation and treatment of mammographic lesions. DESIGN: A computer-generated mathematical model was developed based on clinical outcome modeling to estimate costs accrued during evaluation and treatment of suspicious mammographic lesions. Total costs were determined for evaluation and subsequent treatment of cancer when either SCB or NLB was used as the initial biopsy method. Cost was estimated by the cumulative work relative value units accrued. The risk of malignancy based on the Breast Imaging Reporting Data System (BIRADS) score and mammographic suspicion of ductal carcinoma in situ were varied to simulate common clinical scenarios. MAIN OUTCOME MEASURES: Total cost accumulated during evaluation and subsequent surgical therapy (if required). RESULTS: Evaluation of BIRADS 5 lesions (highly suggestive, risk of malignancy = 90%) resulted in equivalent relative value units for both techniques (SCB, 15.54; NLB, 15.47). Evaluation of lesions highly suspicious for ductal carcinoma in situ yielded similar total treatment relative value units (SCB, 11.49; NLB, 10.17). Only for evaluation of BIRADS 4 lesions (suspicious abnormality, risk of malignancy = 34%) was SCB more cost-effective than NLB (SCB, 7.65 vs. NLB, 15.66). CONCLUSIONS: No difference in cost-benefit was found when lesions highly suggestive of malignancy (BIRADS 5) or those suspicious for ductal carcinoma in situ were evaluated initially with SCB vs. NLB, thereby disproving the hypothesis. Only for intermediate-risk lesions (BIRADS 4) did initial evaluation with SCB yield a greater cost savings than with NLB.

Clinical immunoscintigraphy of recurrent ovarian cancer with indium 111-labeled B72.3 monoclonal antibody.

OBJECTIVE: To prospectively evaluate the ability for immunoscintigraphy with monoclonal antibody CYT-103 labeled with indium 111 to detect tumor presence in 15 patients with ovarian cancer undergoing second-look surgery. DESIGN: Prospective, open-label, nonrandomized trial. SETTING: Hospital-based nuclear medicine facility and operating room. STUDY PARTICIPANTS: Patients with previous ovarian cancer scheduled for second-look surgery. MAIN OUTCOME MEASURE: Correctness of prediction of immunoscintigraphy for presence or absence of ovarian cancer compared with serum CA 125 titer and computed tomography. RESULTS: Immunoscintigraphy, computed tomography, and serum CA 125 titer had respective sensitivities of 92%, 42%, and 42%; specificities of 67%, 100%, and 100%; accuracies of 87%, 53%, and 53%; and diagnostic values of 59%, 42%, and 42%. The full regional extent of recurrent tumor was correctly detected in 45% of patients by immunoscintigraphy and in none of the patients by computed tomography. Immunoscintigraphy detected miliary tumor in two of four patients and computed tomography, as expected, was unable to detect miliary disease. CONCLUSIONS: Recurrent ovarian cancer often presents as multiple small lesions throughout the abdominal cavity. In this subset of patients, immunoscintigraphy may be particularly well suited for detection of the presence of recurrent tumor.