SURPRISINGLY FEW WOMEN WITH SEVERE OSTEOPOROSIS BY BONE DENSITOMETRY UNDERGO WORKUP FOR SECONDARY CAUSES - A RETROSPECTIVE EVALUATION

We describe clinical features of women with extremely low bone density, and investigate secondary causes of osteoporosis. Our hypothesis was that this population would be enriched in identifiable causes of osteoporosis. We performed a retrospective review of medical records of all women seen at our university over 4 years with T-score on bone densitometry at/below -4 at any site. Historical and fracture details were abstracted. We considered a thorough work up to include Vitamin D, PTH, CBC, chemistry panel, cortisol, transglutaminase, myeloma screen, tryptase and 24-hour urine calcium.

RESULTS

137 women were identified with T-score at/below -4. Percent identified as Asian was 26% (higher than local prevalence of 8%). Average BMI was 21.6 kg/m². Clearly identifiable causes of osteoporosis were noted in 57% (inflammatory disorder, glucocorticoid or antacid exposure, prolonged immobilization and alcoholism were most prevalent). Of the remainder, full work up was performed only in 8%. Endocrine consultation and white race predicted thoroughness of secondary work-up.

CONCLUSION

Fragility fractures, leanness and Asian race were common in women with very low T-score. However, few new causes were identified. Underlying etiology was either immediately evident or inadequately studied, especially in minorities.

Common mental disorders among Irish jockeys: prevalence and risk factors

OBJECTIVE

Jockeys compete in a sport, horseracing, renowned for its physical and psychological demands. Previous research has identified that common mental disorders (CMDs) may be prevalent among this unique population of athletes. The aim of the present study was to further explore the prevalence of CMDs among jockeys and to test for associations with potential risk factors.

METHODS

An anonymous survey was distributed to professional jockey online. Self-report screening tools for four CMDs (psychological distress, depression, generalized anxiety, and adverse alcohol use) were included alongside predictor variables from questionnaires assessing for burnout, career satisfaction, social support, and the contemplation of retirement. Binary logistic regression was used to explore associations between CMDs (present versus not present) and risk factors. Eighty-four professional jockeys completed the questionnaire (response rate = 52%).

RESULTS

In total, 79% of jockeys met the threshold for at least one CMD. Prevalence (%) of CMD varied as follows: adverse alcohol (61%), depression (35%), generalized anxiety (27%), and psychological distress (19%). Burnout, career (dis)satisfaction, lower levels of social support, and the contemplation of retirement increased the odds of meeting the criteria for CMDs.

CONCLUSION

The findings indicate that jockeys report CMD symptoms at comparable rates to athletes in other sports. The study was the first to highlight potential risk factors as predictors of CMDs among jockeys, including burnout, career satisfaction, and the current contemplation of retirement. Screening tools for the risk factors demonstrated may, therefore, provide useful in the early identification of CMDs among jockeys. The development of jockey-specific assessment tools, education programmes, and interventions may help better understand and support the mental health of jockeys.

Midface toddler excoriation syndrome (MiTES) can be caused by autosomal recessive biallelic mutations in a gene for congenital insensitivity to pain, PRDM12

BACKGROUND

Midface toddler excoriation syndrome (MiTES) is a condition recently reported in three unrelated children. Habitual scratching from the first year of life inflicted deep, chronic, scarring wounds around the nose and eyes. One child had a mild neurological deficit but there was no other evidence of insensitivity to pain. Bilateral distribution and localization to the midface distinguish MiTES from other causes of self-inflicted skin damage such as trigeminal trophic syndrome. An earlier study of five siblings from a consanguineous Irish family, with lesions corresponding to MiTES plus other sensory deficits, showed homozygous mutations in a gene for hereditary sensory and autonomic neuropathy type VIII (HSAN8), PRDM12.

OBJECTIVES

To study further cases of MiTES, including analysis of PRDM12.

METHODS

We describe five further children, from four families, with facial lesions typical of MiTES, in whom mutation analysis of PRDM12 was carried out.

RESULTS

Homozygous or compound heterozygous pathogenic expansions of the PRDM12 polyalanine tract were found in four of five affected individuals, in three families.

CONCLUSIONS

Our finding of autosomal recessive mutations in PRDM12 in four of five patients with MiTES extends the phenotypic spectrum of PRDM12 mutations, which usually cause HSAN8, characterized by mutilating self-inflicted wounds of the extremities, lips and tongue. By contrast, MiTES shows severe midfacial lesions with little if any evidence of generalized pain insensitivity. The condition is probably genetically heterogeneous, and other congenital insensitivity to pain and HSAN genes such as SCN11A may be implicated. This new understanding of the nature of MiTES, which can masquerade as factitious disease, will facilitate appropriate management.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Behavioural weight management for the primary careprovider

Primary care providers (PCPs) provide the majority of weight management care in clinical settings; however, they often lack the time or resources to apply strategies recommended in treatment guidelines. This review surveyed randomized clinical trials and prospective weight management studies from 1990 to present to identify evidence-based behavioural strategies for weight management applicable to the PCP treatment environment. Data supported, time-limited weight management strategies included self-monitoring, portion control, sleep hygiene, restaurant eating and television viewing. The current review suggests that a number of behavioural strategies are available to enhance the effectiveness of PCPs weight management interventions. Increasing PCP awareness of these evidence-based strategies may increase their attention to overweight and obesity concerns in clinical encounters and encourage more collaborative efforts with patients towards weight management goals.

Clinical evaluation of the Vitek automated system with cards GNS 122 and 127 and VTK-R07.01 software for antimicrobial susceptibility testing of Pseudomonas aeruginosa

The performance of the Vitek Automated Susceptibility Testing System software version VTKR07.01 (bioMerieux Vitek, Hazelwood, MO), for testing Pseudomonas aeruginosa was evaluated by comparing results for 200 clinical isolates with those of disk diffusion and manual broth microtiter dilution testing. For cefepime, the restricted major error rate was 0.53% and the minor error rate was 12.5%. For piperacillin, the restricted major error rate was 2.15%. For ticarcillin/clavulanic acid, restricted very major and major error rates of 6.5% and 3.2%, respectively, occurred. The results of our study indicate that the Vitek system performs within acceptable limits when testing piperacillin, but remains problematic for testing cefepime and ticarcillin-clavulanic acid.

Evidence that natural killer cells express mini P-glycoproteins but not classic 170 kDa P-glycoprotein

Several lines of evidence including reverse transcription polymerase chain reaction, immunoreactivity and their ability to efflux rhodamine 123 have implied the existence of P-glycoprotein in natural killer (NK) cells. It has been a natural tendency to assume that NK-cell P-glycoprotein is identical to the P-glycoprotein of multidrug resistant (MDR) cell lines, however, the present study uncovered major differences. Functionally, NK cells demonstrated a restricted substrate profile, being unable to transport daunorubicin and calcein acetoxymethylester while efficiently transporting other P-glycoprotein substrates. Furthermore, physical differences in NK-cell P-glycoprotein were established by differential reactivity with P-glycoprotein antibodies. NK cells demonstrated strong reactivity with C494 and JSB-1, but did not react appreciably with C219. In addition, NK cells were unable to bind to the antibody MM4.17 unless they had been fixed and permeabilized, yet this antibody normally recognizes an extracellular epitope of P-glycoprotein. These differences culminated in the demonstration using Western analysis that NK cells did not express detectable levels of 170 kDa P-glycoprotein. Instead, NK cells expressed small-molecular-weight 'mini P-glycoprotein' products, of approximately 70 and 80 kDa. Collectively, these data indicate that the predominant P-glycoprotein species of NK cells are novel mini P-glycoproteins and not the classic P-glycoprotein of MDR models.

The role of clinical suspicion in evaluating a new diagnostic test for active tuberculosis: results of a multicenter prospective trial

CONTEXT

In laboratory trials, nucleic acid amplification tests for the diagnosis of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear microscopy and are faster than culture. The impact of these tests on clinical diagnosis is not known.

OBJECTIVE

To assess the performance of a nucleic acid amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test, against a uniform clinical standard stratified by level of clinical suspicion.

DESIGN

Prospective multicenter trial conducted between February and December 1996, documenting the clinical suspicion of TB at enrollment and using final comprehensive diagnosis as the criterion standard.

SETTING

Six urban medical centers and 1 public health TB clinic.

PATIENTS

A total of 338 patients with symptoms and signs consistent with active pulmonary TB and complete clinical diagnosis were stratified by the clinical investigators to be at low (< or =25%), intermediate (26%-75%), or high (>75%) relative risk of having TB.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive values of the E-MTD test in clinical suspicion of groups with low (n = 224); intermediate (n = 68); and high (n = 46) clinical suspicion of TB.

RESULTS

Based on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%, and 87% for low, intermediate, and high clinical suspicion of TB, respectively, and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100% (high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear. Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E-MTD test) vs 96%, 71%, and 37% (AFB smear).

CONCLUSIONS

For complex diagnostic problems like TB, clinical risk assessments can provide important information regarding predictive values more likely to be experienced in clinical practice. For this series, a clinical suspicion of TB was helpful in targeting areas of the clinical spectrum in which nucleic acid amplification tests can make an important contribution.

Stroke prevention trial in sickle cell anemia

Stroke occurs in 7-8% of children with Sickle Cell Disease (Hb SS) and is a major cause of morbidity. Rates of recurrence have been reduced from 46-90% to less than 10% through chronic blood transfusions. Prevention of first stroke, however, would be preferable because even one stroke can cause irreversible brain injury. Transcranial Doppler (TCD) ultrasound can detect arterial blood flow rates associated with subsequent stroke risk. By combining TCD screening and a potentially effective treatment, first stroke may be prevented. The Stroke Prevention Trial in Sickle Cell Anemia (STOP) is the first stroke prevention trial in Hb SS and the first randomized, controlled use of transfusion in Hb SS. This multi-center trial is designed to test whether reducing sickle hemoglobin to 30% or less with periodic blood transfusions will reduce first-time stroke by at least 70% compared to standard care. Primary endpoints will be clinically evident symptoms of cerebral infarction with consistent findings on Magnetic Resonance Imaging and Angiography (MRI/MRA) or symptomatic intracranial hemorrhage. Secondary endpoints will be asymptomatic brain lesions detected by MRI in brain areas not involved in primary endpoints. The design calls for a 6-month start-up interval, 18 months of TCD screening and randomization, and observation for stroke from entry through month 54. Key features of the trial are standardized TCD and MRI/MRA protocols interpreted blindly, and blinded adjudication of endpoints. The sample size (60 per treatment group) is based on prospective data relating TCD velocity to risk of stroke. A time-averaged mean velocity of > or = 200 cm/sec is associated with a 46% risk of cerebral infarction over 39 months. The sample size is sufficient to detect 70% reduction in the primary endpoint at 90% power. This trial will determine if transfusion is effective in the primary prevention of stroke. Secondary aims may further the understanding of the effects of transfusion on the brain and guide future research into cerebrovascular disease in Hb SS.

Comparison of the BacT/Alert and Isolator blood culture systems for recovery of fungi

The recovery of fungi by the BacT/Alert (Organon Teknika Corporation, Durham, NC) and Isolator (Wampole Laboratories, Cranbury, NJ) blood culture systems was compared by retrospective review of 2,174 matched cultures from 715 patients collected from April 1, 1993 to February 28, 1994. One hundred five isolates were recovered from 44 patients by one or both culture systems. All patients were fungemic with one organism. In all cases of fungemia, collection times for both culture systems were within 6 hours of each other. Of 22 isolates of Candida spp, the Isolator recovered all 22 isolates whereas the BacT/Alert recovered 15 (68.2%) (P < .05). The Isolator detected more isolates of Cryptococcus neoformans (10 of 11) than did the BacT/Alert (7 of 11). All 64 isolates of Histoplasma capsulatum (P < .0001) and 6 isolates of Malassezia furfur (P < .05) were recovered by the Isolator system only. For 20 isolates recovered by both systems for which time to recovery could be determined, the mean time to detection of growth was 2.9 days (range 0-9 days) for the Isolator and 2.1 days (range 0-5 days) for the BacT/Alert. In conclusion, the Isolator blood culture system is superior to BacT/Alert for the detection of fungemia, including fungemias caused by Candida spp, H capsulatum, and M furfur.

Male neonatal death and progressive weakness and immune deficiency in females: an unknown X linked condition

We report a family with an undiagnosed X linked condition. The grandmother, two of her three daughters, and one of her grand-daughters have a slowly progressive proximal weakness, brisk reflexes, poor bladder function, static reduced night vision, and IgG2 deficiency. The diagnosis of the three living symptomatic females was "hereditary spastic paraplegia plus". They have lost five male children who died in the neonatal period of severe hypotonia and were of low birth weight. Investigations have not led to a unifying diagnosis: myotonic dystrophy, NARP, and X linked hyper IgM were specifically eliminated. Using the hypothesis that the condition is X linked dominant, haplotype analysis of the family suggests that the disease locus is within Xq26-qter. This entity should be considered in the differential diagnosis of families presenting with severe neonatal hypotonia in males and females with symptoms suggestive of complex hereditary spastic paraplegia.

Cluster analysis of MCMI and MCMI-II on chronic PTSD victims

A cluster analysis was used to identify groups of inpatients with confirmed post-traumatic stress disorder (PTSD) due to combat. In Study 1 the MCMI was administered to 256 subjects, in addition to the MMPI, PTSD measures, and background variables. Three clusters resulted: a Traumatic Personality (8-2), Schizoid Influence (8-2-1), and Antisocial Influence (8-6). Comparison on the MCMI symptom scales, MMPI, and PTSD scales showed that the Antisocial Influence cluster was "healthier" on all measures. The Schizoid Influence was most psychopathological. In Study 2 the MCMI-II was administered to 136 new subjects who met the same criteria as in Study 1. Four clusters resulted: Global (1-2-6A-6B-8A-8B), Subclinical (1), Aggressive (6A-6B-8A), and Detached/Self-defeating (1-2-8A-8B).

Gay re-readings of the Harlem Renaissance poets

In the light of the long-established fact of their homosexuality or bisexuality, it is high time for the cluster of "Negro Renaissance" poets, Countee Cullen, Langston Hughes, Claude McKay, and Richard Bruce Nugent, to be reappraised by and for gay readers. This paper seeks to develop gay reading strategies in relation to the poems of these writers, in order to reveal for contemporary readers likely subtexts which, at the time of their writing, were publicly read as bearing on race alone. It is often possible to read a particular poem as referring (in images such as that of the social outcast) to either racial or sexual oppression, interchangeably; and possibly, therefore, to both at once, by way of an implicit comparison. Likewise, poems on miscegenation can just as well be read, via the theme of forbidden love, as referring to homosexuality. The fact that most published critical readings deal only with the racial issue does not invalidate the likelihood that the poem can be, and indeed requires to be, read as referring, also, to sexuality. Gay readings emerge, then, not merely from these writers' representations of attractive men and boys, but also in the midst of their most famously anti-racist themes.

Relationship between the Millon Clinical Multiaxial Inventory and the Millon-II: value of scales for Aggressive and Self-defeating personalities in Posttraumatic Stress Disorder

This study addressed two issues, the interrelationship between the Millon Clinical Multiaxial Inventory (MCMI) and the Millon II (MCMI-II) and the value of the new personality scales, Aggressive and Self-defeating, in a sample with diagnoses of combat-related Posttraumatic Stress Disorder. 100 confirmed cases of combat-related Posttraumatic Stress Disorder were given a battery of measures including both Millon inventories and the Minnesota Multiphasic Personality Inventory (basic scales and selected subscales). They were rated on discharge status during a structured treatment program. Basic treatment and background information were also obtained. Analysis showed scores on the MCMI-II scales were higher but generally reflective of MCMI scales and that the Self-defeating personality style tends to be reflective of greater psychopathology, suicidal problems, treatment/disposition difficulties, overreporting of symptoms, and intensity of problems. Discussion encouraged the use of the MCMI-II with special emphasis given to the Self-defeating style in this group with Posttraumatic Stress Disorder.

Hospital-acquired infection with vancomycin-resistant Enterococcus faecium transmitted by electronic thermometers

OBJECTIVES

To describe an epidemic of vancomycin-resistant Enterococcus faecium causing bacteremia and bacteriuria, to identify the source of infection, to delineate risk factors associated with acquisition of the organism, and to determine antibiotic sensitivities for the organism.

DESIGN

Investigation of an epidemic, including a case-control study.

SETTING

Medical-surgical intensive care unit and ward in a university medical center.

PATIENTS

Nine patients infected or colonized with vancomycin-resistant Enterococcus faecium and 20 noninfected controls.

MEASUREMENTS

Clinical data, environmental surveillance cultures, and in-vitro microbiologic studies.

RESULTS

Colonization or infection by vancomycin-resistant E. faecium was associated with an increased duration of treatment with ceftazidime, 13.2 compared with 4.6 days, and a greater number of nonisolated days of hospitalization in the intensive care unit, 19.9 compared with 6.4 days for infected and noninfected patients, respectively (P less than 0.05). Environmental surveillance cultures recovered the organism repeatedly from the rectal probe handles of three electronic thermometers used exclusively on nonisolated patients in the intensive care unit. Restriction endonuclease analysis of plasmid DNA showed that all clinical and environmental isolates were identical. Infection control measures, including isolation of colonized or infected patients and removal of the rectal thermometer probes suspected to be responsible for transmission, resulted in termination of the outbreak. In-vitro, time-kill studies showed that the combination of ciprofloxacin, rifampin, and gentamicin resulted in bactericidal activity against the organism.

CONCLUSIONS

This nosocomial outbreak of infection due to a highly vancomycin-resistant strain of Enterococcus is the first epidemic in which an electronic thermometer has been implicated as the vehicle of transmission for an infectious agent.

Prenatal protocol usage

A review was conducted of 825 obstetrics cases on active computer file at the Department of Family and Community Medicine in Little Rock, Arkansas. Independent raters evaluated faculty and resident usage of a prenatal protocol which was routinely used as a teaching tool in the department's residency program since 1972. Significant differences were found to exist with regard to usage of the tool by physician status. Faculty were more consistent and thorough in their usage of the teaching tool when compared to residents. Differences were explained in terms of a practice effect, research bias of faculty, levels of practice, and potential weaknesses in the educational program.

Dehydroepiandrosterone and estrone 17-ketosteroid reductases in MCF-7 human breast cancer cells

The identification of several steroid-transforming enzymes within human breast cancers has led to speculation that the growth of some hormone-responsive tumors might be mediated in part by intracellularly derived estrogens. Reports that MCF-7 human breast cancer cells can transform both estrone (E1)1 to estradiol (E2) and dehydroepiandrosterone (DHEA) to the estrogenic steroid 5-androstenediol (AED), have prompted us to investigate the 17-ketosteroid reductase activities (17-KSR's) which mediate these potentially important reactions. Enzyme assays were performed by quantifying the amounts of [3H]AED or [3H]E2 former from [3H]DHEA or [3H]E1, respectively, by various subcellular preparations from MCF-7 cells under a variety of experimental conditions. DHEA 17-KSR was found to be localized exclusively within cytosol, whereas the E1 17-KSR activity appeared to be nearly equally divided between the soluble and particulate cytoplasmic subfractions. The particulate E1 17-KSR appeared capable of utilizing NADH or NADPH, whereas both the cytosolic form of this enzyme and the soluble DHEA 17-KSR activity showed a strict requirement for NADPH. Although both of the soluble 17-KSR's also showed similar pH optima, several other features suggested that they are different enzymes in MCF-7. E1 did not inhibit the conversion of DHEA to AED, and DHEA did not interfere with the transformation of E1 to E2, indicating that major differences in substrate specificity exist between the two cytosolic activities. Furthermore, DHEA 17-KSR activity within cytosol stored at -20 degrees C deteriorated almost completely over twelve weeks of storage, whereas E1 17-KSR activity remained stable. Finally, although both enzymes were found to be subject to product inhibition, AED inhibited DHEA 17-KSR competitively, whereas cytosolic E1 17-KSR activity was inhibited by E2 in noncompetitive fashion. Studies of the oxidation of E2 to E1 by MCF-7 cells showed that this transformation is catalyzed by both soluble and particulate 17-hydroxysteroid oxidases which utilize either NAD or NADP as cofactor. Having previously reported the presence of a particulate NADP(H)-linked androstenedione (AE) 17-ketosteroid oxidoreductase in MCF-7, we now suggest that at least three different enzymes, one particulate and two soluble forms, participate in the conversion of 17-ketosteroids to their hormonally active 17-hydroxysteroid derivatives within this cell line. The restricted substrate requirements of each enzyme provide a rationale for developing selective enzyme inhibitors which could provide important investigational tools and potentially effective therapeutic agents.

Growth and siderophore production by Bordetella pertussis under iron-restricted conditions

It has been demonstrated that under iron-restricted conditions Bordetella pertussis can obtain iron from iron-saturated human transferrin. Direct contact between B. pertussis and transferrin was not required as B. pertussis was able to acquire iron from transferrin when they were separated by a dialysis membrane. Siderophore activity was detected in supernatants from iron-restricted cultures of B. pertussis, B. bronchiseptica and B. parapertussis. Siderophores were identified as hydroxamates and were produced by both virulent and avirulent strains of B. pertussis.

Diffuse alveolar hemorrhage in autologous bone marrow transplant recipients

PURPOSE

The purpose of our work was to evaluate pulmonary complications in autologous bone marrow transplant recipients.

PATIENTS AND METHODS

A total of 141 consecutive autologous bone marrow transplant recipients were evaluated. In 29 patients, a clinical syndrome characterized by progressive dyspnea, hypoxia, cough, diffuse consolidation on chest roentgenography, and characteristic bronchoalveolar lavage findings developed over one to seven days.

RESULTS

In 29 patients, bronchoalveolar lavage performed by sequential instillation and aspiration of 20-ml aliquots of normal saline resulted in recovered lavage fluid that became progressively bloodier with each recovered aliquot. Autopsy and bronchoalveolar lavage in these patients revealed no pathogens that accounted for the clinical findings. Since the later aliquots sample predominantly alveolar material, this syndrome was termed diffuse alveolar hemorrhage (DAH). DAH was associated with a high inpatient mortality rate (23 of 29 died versus 14 of 112 without DAH, p less than 0.001) and was associated with age over 40 years, solid malignancies, high fevers, severe mucositis, white blood cell recovery, and renal insufficiency (p less than 0.05, compared with patients without DAH). However, DAH was not associated with prolonged prothrombin or partial thromboplastin times or decreased platelet counts compared with patients without DAH.

CONCLUSION

DAH is a frequent cause of respiratory compromise and a major cause of mortality in autologous bone marrow transplant recipients.

Evidence for an involvement of T4+ cytotoxic T cells in tumor immunity

Cell-mediated immunity against cancer cells primarily involves class I major histocompatibility complex (MHC)-restricted cytotoxic T cells and natural killer (NK) cells. To investigate whether T4+ cytotoxic T cells also have a role in tumor-specific immunity, mice were immunized with a B cell lymphoma. T cell hybridomas were constructed from the immune spleen cells and analyzed for their cytotoxic ability against the immunizing lymphoma. A T4+, Lyt-1+ hybridoma cell line was developed (103L2) which specifically killed the immunizing tumor cells but not normal B cells or a range of other tumor cells of B or non-B origin. This cytotoxic hybridoma cell line differed from Lyt-2+ cytotoxic T lymphocyte cells and NK cells, commonly identified with cytotoxicity, in a number of important ways. First, the cells were class II MHC restricted; second, interleukin-2 was released from activated effector cells; and finally but most importantly, innocent nonparticipating bystander cells were also killed. The significance of this observation was that normal cells were protected, although a broad range of tumor cell types, including tumor antigen-negative mutants, were killed. It is therefore conceivable that T4+ cytotoxic T cells might play an important role in tumor immunity through the direct recognition and lysis of tumor cells while any tumor variants, arising due to antigen loss, would remain susceptible through the bystander killing effect and normal cells would remain unaffected. These results strongly suggest that tumor-reactive T4+ cytotoxic T cells belong to a new category of effector cells with an important role in tumor-specific immunity.

Resistance of multidrug-resistant lines to natural killer-like cell-mediated cytotoxicity

Multidrug resistance (MDR) refers to a complex phenotype that describes a number of features characterized primarily by resistance to a wide range of structurally unrelated drugs. In this paper we investigated the relationship between drug resistance and resistance to NK-mediated cytotoxicity. Studies with two independently selected multidrug-resistant cell lines indicated that increased drug resistance was associated with both an increased resistance to NK-mediated cytotoxicity and increased levels of membrane P-glycoprotein expression. This resistance to cytotoxicity appears to result partly from an alteration in the membrane structure of the target cells inasmuch as there was a reduction in effector:target cell recognition. Resistance to NK-mediated cytotoxicity should be included with the numerous pleiotropic changes associated with the multidrug resistance phenotype.

A novel strategy for immunotherapy using antibody-coupled carriers to focus cytotoxic T helper cells

Targeting of cytotoxic T cells to cell-bound antigens has previously been reported using bispecific antibodies. In this report we document a novel targeting system whereby cytotoxic T helper (Thc) cells were targeted to a B cell lymphoma by means of an anti-idiotypic antibody (anti-Id), specific for the surface immunoglobulin of the B cell, coupled to the carrier protein keyhole limpet hemocyanin (KLH). In this system the anti-Id-KLH complex bound to the Id determinant of the surface immunoglobulin of the B cell lymphoma. This complex was then presented in a major histocompatibility complex class II-restricted manner to the KLH-specific Thc cell (KLH55) which was induced into its cytolytic pathway through the specific recognition of KLH. The uniqueness of this system was that it utilized the inherent ability of the target B cell to process and present antigen. This offered the distinct advantage that processed antigen re-expressed on the cell membrane was in a more stable form, thereby enabling the target cell to remain susceptible to cytotoxicity for an extended period of time. Furthermore, as is characteristic of Thc cells in general, bystander killing was demonstrated and Id (or Ia)-negative mutants of the target cell did not escape destruction. The adaptation of such a system will have useful implication for future immunotherapeutic strategies.

Prophylaxis with oral penicillin in children with sickle cell anemia. A randomized trial

Children with sickle cell anemia have an increased susceptibility to bacterial infections, especially to those caused by Streptococcus pneumoniae. We therefore conducted a multicenter, randomized, double-blind, placebo-controlled clinical trial to test whether the regular, daily administration of oral penicillin would reduce the incidence of documented septicemia due to S.pneumoniae in children with sickle cell anemia who were under the age of three years at the time of entry. The children were randomly assigned to receive either 125 mg of penicillin V potassium (105 children) or placebo (110 children) twice daily. The trial was terminated 8 months early, after an average of 15 months of follow-up, when an 84 percent reduction in the incidence of infection was observed in the group treated with penicillin, as compared with the group given placebo (13 of 110 patients vs. 2 of 105; P = 0.0025), with no deaths from pneumococcal septicemia occurring in the penicillin group but three deaths from the infection occurring in the placebo group. On the basis of these results, we conclude that children should be screened in the neonatal period for sickle cell hemoglobinopathy and that those with sickle cell anemia should receive prophylactic therapy with oral penicillin by four months of age to decrease the morbidity and mortality associated with pneumococcal septicemia.

Tissue culture of surgically prepared temporalis fascia

Temporalis fascia which is used to graft the tympanic membrane has been shown to be viable in tissue culture by a previous pilot study. This present study reports the effect on the viability of the fascia by scraping loose connective tissue from it and allowing it to dry. Pieces of fascia from 30 patients were each divided in 4 and prepared to give explants, fresh, fresh and scraped, dried, and dried and scraped. The fascia grew from 17 patients when cultured fresh, 5 when fresh and scraped, 1 when dried, and none when dried and scraped. These results are significantly different and show that the fascia is devitilized when prepared by the normal method for use in tympanoplasty.

Bridging bronchus: a rare airway anomaly

The authors describe an infant whose right-lower-lobe bronchus arose from the left main bronchus and bridged the lower mediastinum. Other major congenital anomalies were present as well. Possible explanations for crossed airways, which would seem to contradict the current theory of embryonic lung development, are suggested.

Sensitivity patterns of urinary pathogens in the Southland community and a study of sewage flora

The overall sensitivity pattern of the three main urinary pathogens to the commonly used oral antibodies exceeded 80 percent. The incidence of multiple resistant Escherichia coli was 8 percent. The resistant patterns of the sewage E. coli resembled that of the resistant urinary E. coli. However only one-third of the resistant urinary E. coli showed multiple resistance whereas two-thirds of the resistant E. coli in the sewage showed this feature. The resistance transfer was low in organisms isolated from the sewage. Regular surveillance of this type may be useful as a guide to therapy and may reflect the impact of continued antibiotic usage in the community.

Translational and rotational diffusion constants of tobacco mosaic virus from Rayleigh linewidths

The translational and rotational diffusion constants of tobacco mosaic virus (TMV) have been determined from homodyne and heterodyne measurements of the spectrum of laser light scattered from dilute aqueous solutions of TMV. Our results for the translational and rotational constants respectively, reduced to 20 degrees C, are: D(T) = 0.280 +/- 0.006 x 10(-7) cm(2)/sec, and D(R) = 320 +/- 18 sec(-1). We include a theoretical derivation of the spectrum of light scattered from rod-shaped molecules which reproduces results obtained previously by Pecora, but which is specialized at the outset to the problem of dilute solutions so that simple single-particle correlation functions may be utilized. An analysis of the photocurrent spectrum for both the homodyne and heterodyne detection schemes is given. Various data reduction schemes utilized in the analysis of our spectra are described in some detail, and our results are compared with values of the diffusion constants obtained from other experiments.