Diet characterisation of solitary bees on farmland: dietary specialisation predicts rarity

Changes in agricultural practice across Europe and North America have been associated with declines in wild bee populations. Bee diet breadth has been associated with sensitivity to agricultural intensification, but much of this analysis has been conducted at the categorical level of generalist or specialist, and it is not clear to what extent the level of generalisation within generalist species is also associated with species persistence. We used pollen load analysis to quantify the pollen diets of wild solitary bees on 19 farms across southern England, UK. A total of 72 species of solitary bees were recorded, but only 31 species were abundant enough to allow for formal diet characterisation. The results broadly conformed to existing literature with the majority of species polylectic and collecting pollen from a wide range of plants. Pollen load analysis consistently identified pollens from more plant species and families from each bee species than direct observation of their foraging behaviour. After rarefaction to standardise pollen load sample sizes, diet breadth was significantly associated with frequency of occurrence, with more generalist bees present on more farms than less generalist bees. Our results show that the majority of bee species present on farmland in reasonable numbers are widely variable in their pollen choices, but that those with the broadest diet were present on the greatest number of farms. Increasing the diversity of plants included in agri-environment schemes may be necessary to provide a wider range of pollen resources in order to support a diverse bee community on farmland.

Preoperative carboplatin and paclitaxel-based chemoradiotherapy for esophageal carcinoma: results of a modified CROSS regimen utilizing radiation doses greater than 41.4 Gy

Trimodality therapy for resectable esophageal and gastroesophageal junction cancers utilizing preoperative radiotherapy with concurrent carboplatin and paclitaxel-based chemotherapy is being increasingly utilized secondary to the results of the phase III CROSS trial. However, there is a paucity of reports of this regimen as a component of chemoradiotherapy in North America. We aim to report on our clinical experience using a modified CROSS regimen with higher radiotherapy doses. Patients with advanced (cT2-cT4 or node positive) esophageal or gastroesophageal junction carcinoma who received preoperative carboplatin/paclitaxel-based chemoradiotherapy with radiation doses of greater than 41.4 Gray (Gy) followed by esophagectomy were identified from an institutional database. Patient, imaging, treatment, and tumor response characteristics were analyzed. Twenty-four patients were analyzed. All but one tumor had adenocarcinoma histology. The median radiation dose was 50.4 Gy. Pathologic complete response was achieved in 29% of patients, with all receiving 50.4 Gy. Three early postoperative deaths were seen, due in part to acute respiratory distress syndrome and all three patients received 50-50.4 Gy. With a median follow-up of 9.4 months (23 days-2 years), median survival was 24 months. Trimodality therapy utilizing concurrent carboplatin/paclitaxel with North American radiotherapy doses appeared to have similar pathologic complete response rates compared with the CROSS trial, but may be associated with higher toxicity. Although the sample size is small and further follow-up is necessary, radiation doses greater than 41.4 Gy may not be warranted secondary to a potentially increased risk of severe radiation-induced acute lung injury.

Significant understaging is seen in clinically staged T2N0 esophageal cancer patients undergoing esophagectomy

This study aimed to determine the impact of preoperative staging on the treatment of clinical T2N0 (cT2N0) esophageal cancer patients undergoing esophagectomy. We reviewed a retrospective cohort of 27 patients treated at a single institution between 1999 and 2011. Clinical staging was performed with computed tomography, positron emission tomography, and endoscopic ultrasound. Patients were separated into two groups: neoadjuvant therapy followed by surgery (NEOSURG) and surgery alone (SURG). There were 11 patients (41%) in the NEOSURG group and 16 patients (59%) in the SURG group. In the NEOSURG group, three of 11 patients (27%) had a pathological complete response and eight (73%) were partial or nonresponders after neoadjuvant therapy. In the SURG group, nine of 16 patients (56%) were understaged, 6 (38%) were overstaged, and 1 (6%) was correctly staged. In the entire cohort, despite being clinically node negative, 14 of 27 patients (52%) had node-positive disease (5/11 [45%] in the NEOSURG group, and 9/16 [56%] in the SURG group). Overall survival rate was not statistically significant between the two groups (P = 0.96). Many cT2N0 patients are clinically understaged and show no preoperative evidence of node-positive disease. Consequently, neoadjuvant therapy may have a beneficial role in treatment.

A regression model for predicting conditional survival for head and neck cancer patients: A SEER analysis

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Background: Survival probability changes as patients survive longer periods of time after diagnosis, and estimates of prognosis at diagnosis are no longer valid. Conditional survival (CS) accounts for the changing hazard rate over time and is a more accurate estimate of survival probability for these cancer survivors. The specific aim of this project was to build a statistical model and web-based tool to predict conditional survival for an individual head & neck cancer patient based on tumor and patient characteristics. Methods: Using 27,825 patients diagnosed with head & neck cancer between 1988–97 from the Surveillance, Epidemiology, and End Results 17 (SEER) database, we built a multivariate Cox proportional hazards regression prediction model. Patient and tumor characteristics included as covariates were age, sex, race, tumor site, stage, and grade. The primary endpoint was conditional overall survival. The model was validated for discrimination using the concordance index and a calibration plot was constructed. Bootstrapping was used to correct for optimistic bias. We also built a web-browser software tool to allow a user to enter patient information into the model and calculate conditional survival probability. Results: The regression model showed very good calibration and discrimination with a bootstrap-corrected C-index of 0.71. For a 65-yr old white male with a moderately-differentiated tonsil cancer with regional lymph nodes, the model predicted that the 5-yr conditional overall survival would increase from 50% at the time of diagnosis to 63% at 3 years after diagnosis. For a 75-yr old black male with a well-differentiated localized lip cancer, 5-yr conditional survival would improve from 58% at diagnosis to 70% by 3 years from diagnosis. Conclusions: Our regression model can accurately predict conditional survival for head & neck cancer patients based upon specific patient and tumor characteristics. This tool allows the calculation of more specific prognosis predictions for individual cancer patients who have already survived a period of time after diagnosis and treatment.

No significant financial relationships to disclose.

Spatio-temporal distribution and emergence of beetles in arable fields in relation to soil moisture

Predatory beetles contribute to the control of crop pests and are an important food resource for farmland birds. Many of these beetle species overwinter as larvae within agricultural soils, however, their spatio-temporal emergence patterns are poorly understood, even though such knowledge can assist with their management for biocontrol. Soil moisture is considered to be a key factor influencing oviposition site selection and larval survival. The time, density and spatial pattern of Carabidae and Staphylidae emergence was therefore measured across two fields and compared to soil moisture levels in the previous winter and adult distribution in the previous July. The mean density of Carabidae and Staphylidae that emerged between April and harvest within each field was 157 and 86 m-2, indicating that soils are an important over-wintering habitat for beneficial invertebrates and should be managed sympathetically if numbers are to be increased. Of the species that were sufficiently numerous to allow their spatial pattern to be analysed, all showed a heterogeneous emergence pattern, although patches with high emergence were stable over the sampling period. The distribution of eight species was influenced by soil moisture levels in the previous winter and eight species, although not the same, were spatially associated with the distribution of adults in the previous summer suggesting that the females selected oviposition areas with the appropriate soil wetness.

The role of large-scale spatially explicit and small-scale localized processes on the population dynamics of cereal aphids

A field-scale study of the spatially explicit interaction between the carabid Poecilus cupreus Linnaeus, and two common aphid species (Sitobion avenae (Fabricius) and Metopolophium dirhodum (Walker)) in winter wheat was conducted. All three species showed considerable spatial pattern at the field scale. Activity-density of P. cupreus was an order of magnitude higher in the central part of the field compared to its periphery. Where P. cupreus activity-density was highest, S. avenae and M. dirhodum population peaks were delayed. Additionally, in the case of M. dirhodum, lower maximum counts were evident where P. cupreus activity-density was highest. An analysis of the movement of individual P. cupreus using release-recapture indicated that those beetles within the centre of the field exhibited reduced displacement, which may have caused the generation or maintenance of spatial pattern. Crop density was also measured throughout the field. Although crop density had no large-scale spatial pattern, its variability at the small-scale was consistent with an influence on aphid population dynamics. This study demonstrates empirically that both large-scale spatially explicit and small-scale localized processes influenced aphid population dynamics simultaneously.

Histological effects of tazarotene 0.1% cream vs. vehicle on photodamaged skin: a 6-month, multicentre, double-blind, randomized, vehicle-controlled study in patients with photodamaged facial skin

BACKGROUND

Topical tazarotene has been shown to offer efficacy in ameliorating multiple effects of photodamage.

OBJECTIVES

To evaluate the histological effects of tazarotene cream on photodamaged skin.

METHODS

In this multicentre, double-blind, randomized, vehicle-controlled study, 50 patients with photodamaged facial skin (at least mild fine wrinkling and mottled hyperpigmentation, with at least one of these being moderate) were randomized to apply tazarotene 0.1% cream or vehicle cream to their face, once daily for 24 weeks.

RESULTS

Blinded assessments showed that tazarotene was less likely than vehicle to be associated with an increase in keratinocytic and melanocytic atypia, and more likely than vehicle to be associated with a reduction in atypia. Between-group comparisons in distribution of change from baseline categories of severity were in favour of tazarotene (P = 0.055 for keratinocytic atypia, P = 0.034 for melanocytic atypia, and P < 0.001 for the number of granular cell layers). Compared with vehicle, tazarotene was associated with an increase in epidermal polarity (P = 0.008) and epidermal thickness (P = 0.012), and a tendency for stratum corneum compaction. Tazarotene was also associated with widened intercellular spaces (reported as epidermal oedema) relative to vehicle (P < 0.001).

CONCLUSIONS

Treatment of photodamaged skin with tazarotene is associated with an amelioration of keratinocytic and melanocytic atypia, an improvement in epidermal polarity, and an increase in epidermal thickness.

The spatial dynamics of crop and ground active predatory arthropods and their aphid prey in winter wheat

The distribution of aphid predators within arable fields has been previously examined using pitfall traps. With this technique predominantly larger invertebrate species are captured, especially Carabidae, but the technique provides no estimate of density unless mark-recapture is used. However, many other numerically important aphid predators occur in arable fields and relatively little is known about their distribution patterns nor whether they exhibit a density-dependent response to patches of cereal aphids. Identification of the most effective predators can allow management practices to be developed accordingly. In this study, the distribution of cereal aphids and their predators was examined by suction sampling within a field of winter wheat in Devon, UK, along with visual estimates of weed patchiness. Sampling was conducted on four occasions in 1999 across a grid of 128 sample locations. The distribution of 11 predatory taxa from the Carabidae, Staphylinidae and Linyphiidae was examined. Additionally, the total number of aphid predators and a predation index were used in these analyses. Carabid adults and larvae, along with staphylinid larvae showed the strongest aggregation into patches and the most temporal stability in their distribution. Other taxa had more ephemeral distributions as did the cereal aphids. The distribution of carabid larvae was disassociated from the distribution of cereal aphids for the first two sampling occasions indicating biocontrol was occurring. Other predatory groups showed both association and disassociation. Carabid larvae, Bathyphantes and total numbers of Linyphiidae showed a strong correlation with weed cover for two of the sample dates. Cereal aphids were disassociated from weed cover on three sampling occasions.

A comparison of the effect of new and established insecticides on nontarget invertebrates of winter wheat fields

Six insecticides, a carbamate (pirimicarb), four pyrethroid/mixtures (tao-fluvalinate, zeta-cypermethrin, deltamethrin, and pirimcarb+deltamethrin), and an organophosphate (dimethoate), registered for use within cereals, were field-tested for toxicity to beneficial nontarget invertebrate groups important as food for farmland birds. Compared to the control and the other compounds, pirimicarb was the least toxic for most invertebrate groups examined. The pyrethroids and pyrethroid mixture significantly reduced numbers of many of the nontarget groups compared to the control and pirimicarb. Tao-fluvalinate was the least toxic pyrethroid tested when compared to the other compounds. Toxicity was further tested on larvae of graminivorous sawflies, an important chick- food group, using field-sprayed plants in laboratory and semifield trials. None of the pyrethroid and carbamate compounds and mixtures was as toxic as the organophosphate, but all were more toxic than the control. The semifield experiments provided a useful way of determining potential insecticide impact on this nontarget group where field populations are often too low for field trials to have statistically conclusive results.

Prevention of local recurrence after surgical debulking of nodal and subcutaneous melanoma deposits by hypofractionated radiation

BACKGROUND

Local recurrence (LR) after surgical debulking of nodal or subcutaneous melanoma deposits defeats the purpose of operation and may worsen prognosis if the procedure was performed for stage III disease. To decrease LR rates in this setting, we extended the previously described role of hypofractionated radiation for melanoma deposits of the neck to all situations where the patient was felt to be at high risk for postoperative relapse after resection of bulky disease.

METHODS

Hypofractionated external beam radiation was administered in 6-Gy doses for 5 fractions (total dose 30 Gy, given over a median of 15 elapsed days) to 42 resected melanoma deposit sites in 41 patients.

RESULTS

Stages of the 41 patients at the time of treatment were: 22 stage III and 19 stage IV. All patients had complete gross resection of disease at the radiation site before radiation. Mean time between operation and initiation of radiation was 4 weeks. The 42 sites of treatment included 27 neck, 9 axilla, 3 groin, and 3 subcutaneous deposits. There were no treatment-related deaths; side effects were minimal and self-limited. Transient erythema, desquamation, fibrosis, telangiectasias, and mucositis, parotiditis, and xerostomia (for head and neck radiation) were reported, but no patient required interruption of therapy for these events. Of the 42 treated sites, only 2 recurred in the treatment field (one neck, one axilla) during the mean follow-up time of 22.4 months, for a treatment failure rate of 4.8%. This represents improved local control compared with patients treated with surgery alone at our institution and with published recurrence rates.

CONCLUSIONS

The addition of hypofractionated radiation therapy after resection of nodal and subcutaneous melanoma deposits at a variety of sites is a rapid and well-tolerated method of providing excellent local control.

Cranial neuropathy following curative chemotherapy and radiotherapy for carcinoma of the nasopharynx

Cranial nerve damage following head and neck radiotherapy is an unusual event. Cranial neuropathy following concurrent chemotherapy and radiotherapy is unreported. The authors report a case of a 54-year-old man treated with curative chemotherapy and radiotherapy for a stage III nasopharyngeal carcinoma who developed an unilateral hypoglossal nerve palsy five years after therapy. Follow-up examination and magnetic resonance imaging (MRI) show no evidence of recurrent disease. Hypoglossal nerve injury occurring after head and neck radiotherapy is an indirect effect due to progressive soft tissue fibrosis and loss of vascularity. This process develops over years leading to nerve entrapment and permanent damage. Cranial nerve palsies, including damage to the hypoglossal nerve, can develop years after therapy with no evidence of tumour recurrence. Chemotherapy and radiotherapy have improved progression-free and overall survival in advanced nasopharyngeal cancer. As more patients achieve long-term tumour control following chemotherapy and radiotherapy, we must be cognizant of potential late injury to cranial nerves.

Molecular detection of prostate epithelial cells from the surgical field and peripheral circulation during radical prostatectomy

PURPOSE

Prostate cancer progression despite organ confined pathological assessment has been reported in a variable number of men after radical retropubic prostatectomy. To study this phenomenon, we used the prostate specific antigen (PSA) reverse transcriptase-polymerase chain reaction assay.

MATERIALS AND METHODS

We prospectively assayed the peripheral venous blood before, during and after surgical manipulation as well as the intraoperative field blood for PSA reverse transcriptase-polymerase chain reaction-positive cells in 22 men undergoing radical retropubic prostatectomy.

RESULTS

PSA reverse transcriptase-polymerase chain reaction-positive cells were identified in 20 of the 22 operative field samples (91%) and 4 of 16 (25%) had evidence of intraoperative hematogenous dissemination (p = 0.046). No significant association was identified among Gleason score, pathological stage and the PSA reverse transcriptase-polymerase chain reaction result.

CONCLUSIONS

Our results suggest that tumor cell spillage and less frequently hematogenous dissemination may be associated with operative manipulation of the prostate during radical retropubic prostatectomy and may potentially represent mechanisms of failure after radical retropubic prostatectomy.

Molecular detection of prostate epithelial cells from the surgical field and peripheral circulation during radical prostatectomy

PURPOSE

Prostate cancer progression despite organ confined pathological assessment has been reported in a variable number of men after radical retropubic prostatectomy. To study this phenomenon, we used the prostate specific antigen (PSA) reverse transcriptase-polymerase chain reaction assay.

MATERIALS AND METHODS

We prospectively assayed the peripheral venous blood before, during and after surgical manipulation as well as the intraoperative field blood for PSA reverse transcriptase-polymerase chain reaction-positive cells in 22 men undergoing radical retropubic prostatectomy.

RESULTS

PSA reverse transcriptase-polymerase chain reaction-positive cells were identified in 20 of the 22 operative field samples (91%) and 4 of 16 (25%) had evidence of intraoperative hematogenous dissemination (p = 0.046). No significant association was identified among Gleason score, pathological stage and the PSA reverse transcriptase-polymerase chain reaction result.

CONCLUSIONS

Our results suggest that tumor cell spillage and less frequently hematogenous dissemination may be associated with operative manipulation of the prostate during radical retropubic prostatectomy and may potentially represent mechanisms of failure after radical retropubic prostatectomy.

Phantom orchalgia

Chronic scrotal pain is most commonly explained by the radiculitis that is caused by low back strain. The diagnosis is made chiefly by taking a careful history and by excluding other causes. Treatment directed to relieve sensory nerve root irritation at the T10 to L1 levels is often successful.

Emergency department patterns in psychiatric visits during the holiday season

STUDY OBJECTIVE

To determine the prevalence of psychopathology during the holiday season and which subpopulations are at greatest risk for holiday decompensation.

DESIGN

A retrospective analysis of emergency department records.

SETTING

ED of a university-affiliated hospital located in a mixed urban-agricultural catchment area in North Carolina.

PARTICIPANTS

Eight thousand seven hundred fifty-six patient visits to the ED, with subsequent triage for psychiatric evaluation, for a 6-year period (1987 to 1993), were analyzed.

RESULTS

We observed seasonal patterns in visits, with a general decrease in visits preceding holidays followed by an increase afterward. Substance abusers, men, and black patients were more likely to visit the ED than expected, particularly during the weeks surrounding Christmas.

CONCLUSION

These results support the existence of a "Christmas effect" on ED visitations by patients with psychiatric symptoms. Understanding of these patterns may help emergency physicians predict the seasonal variation of such patient visits and apply preventive measures accordingly.

Tolerance of patients with human immunodeficiency virus and anal carcinoma to treatment with combined chemotherapy and radiation therapy

PURPOSE

To evaluate treatment tolerance in patients with and without the human immunodeficiency virus (HIV) who were undergoing treatment of anal cancer.

MATERIALS AND METHODS

The authors retrospectively reviewed the medical records of 62 patients with anal cancer who received radiation treatment. Seven patients had HIV, four of whom had acquired immunodeficiency syndrome. Fifty-five patients were HIV negative, including 11 patients identified as being at high risk for HIV infection whose status was unknown.

RESULTS

Thirty of the 55 (55%) patients who were HIV negative required treatment breaks of a mean duration of 16.7 days. Four of those 55 (7%) patients required hospitalization. Three of 42 (7%) patients who were HIV negative receiving chemotherapy required chemotherapy dose reduction. All seven patients with HIV required treatment breaks of a mean duration of 21.7 days. Three of the seven (43%) patients required hospitalization. Four of the seven (57%) patients required chemotherapy dose reduction.

CONCLUSION

Patients with HIV undergoing treatment of anal cancer have increased toxic reactions to chemoradiation. Treatment must be individually tailored on the basis of extent of disease and degree of compromise of the immune system.

Extragonadal seminoma involving urinary bladder and arising in the prostate

The authors report the first instance of a patient with seminoma probably arising from the prostate but also involving the bladder. A 58-year-old man presented with symptoms and signs of prostatic enlargement. Cystoscopy revealed a fungating neoplasm, probably arising from the prostate and surrounding the bladder neck. The biopsy was consistent with the diagnosis of seminoma. The patient experienced complete remission after chemotherapy with bleomycin, cisplatin, and etoposide.

Effects of irradiation on nuclear protein synthesis in G2 phase of the cell cycle

A method was developed to determine the synthesis of nuclear proteins throughout the cell cycle which was resolved into six compartments on the basis of DNA and nuclear protein content (i.e., early and late G1, early and late S, etc). Using this technique cell-cycle-specific synthesis of certain nuclear proteins was observed. Of particular interest was a 170-kDa protein(s) whose synthesis was initiated in early S phase and reached a maximum rate in late G2. Following irradiation with 6.8 Gy of 137Cs gamma rays the synthesis of the 170-kDa protein(s) declined in the G2 population with near total inhibition seen by 24 h. Synthesis of the 170-kDa protein(s) appeared to be slightly enhanced, and the postirradiation inhibition of its synthesis was reversed, in the presence of 3 mM caffeine. Also, the synthesis of 55-kDa nuclear protein(s) was stimulated throughout the cell cycle in the presence of 3 mM caffeine. These observations suggest new possibilities regarding the mechanism of the X-ray-induced G2 block and its reversal by caffeine. However, the exact role of these nuclear proteins in cellular events remains to be ascertained.

Comparative effects of caffeine on radiation- and heat-induced alterations in cell cycle progression

The effects of 3 mM caffeine on cell cycle progression of HeLa S3 cells exponentially and asynchronously growing in suspension culture were studied following exposure to 6.8 Gy gamma irradiation or 30 min at 45 degrees C hyperthermia. The stathmokinetic method, in which cells are grown in the presence of colcemid for the duration of experiment, in combination with two flow cytometric techniques, propidium iodide staining of DNA and acridine orange staining following acid denaturation of chromatin, were used to determine the fraction of cells in four cell cycle compartments, G1, S, G2, and M. Radiation and caffeine acted in a complementary manner, in which radiation reduced the caffeine-induced delays in cell cycle progression and caffeine prevented completely the radiation-induced accumulation of cells in G2 and mitotic delay. Heat and caffeine had additive effects on alterations in cell cycle progression. Cells containing spontaneous prematurely condensed chromatin were observed transiently immediately following heat exposure. These cells appeared to be in G2 and late S phase.

Minoxidil stimulates mouse vibrissae follicles in organ culture

Minoxidil, a potent vasodilator, stimulates the growth of terminal hair from vellus or miniaturized follicles in balding scalp. To study minoxidil's action on isolated follicles we developed and validated an organ culture system using mouse whisker follicles. Control follicles cultured without minoxidil showed macroscopic changes including kinking of the hair shafts and bending of the follicles. Necrosis was evident in the differentiating epithelial elements forming the cuticle, cortex, and inner root sheath. These abnormalities were eliminated or greatly reduced in minoxidil-treated follicles. The morphology of these follicles was consistent with the production of new hair during culture. Direct measurement demonstrated that minoxidil-treated follicles grew significantly longer than control follicles during the 3-d culture. Minoxidil increased the incorporation of radiolabeled cysteine and glycine in follicles compared with control treatment. Doses of minoxidil up to 1 mM caused increased cysteine incorporation, while higher doses were inhibitory. Experiments with labeled thymidine indicated that minoxidil induced proliferation of hair epithelial cells near the base of the follicle. Autoradiography also showed that cysteine accumulated in the keratogenous zone above the dermal papilla. These studies demonstrate that organ cultured follicles are suitable for determining minoxidil's mechanism of action and may be useful for studying other aspects of hair biology. The results also show that minoxidil's effect on hair follicles is direct. This suggests that minoxidil's action in vivo includes more than just increasing blood flow to hair follicles.

Animal models of alopecia

A genetic model of androchronogenic alopecia has yet to be described in the rat or mouse, two of the better characterized species. It may be relevant that the best current animal model of androchronogenic alopecia, the stumptailed macaque, is a primate. The age of onset and the pattern of hair loss closely resemble human male-pattern baldness and morphologically, as well as mechanistically, may be analogous to the corresponding process in humans. Since genetically controlled regional hairlessness is a phenomenon relatively unique to Homo sapiens, it may be too much to expect to find an analogous process among rodents.

Prostatic aspiration biopsy: an assessment of accuracy based on long-term observations

We present the results of transrectal thin needle aspiration biopsy of the prostate in 133 patients. Test specificity was 94 per cent and sensitivity also appeared to be high initially. However, with repeated rectal examinations and biopsies during an 11-year period a number of additional false negatives became apparent, which resulted in an apparent test sensitivity of 82 per cent, lower than most previously published reports. Our data suggest that aspiration biopsy has specificity and sensitivity similar to core biopsy, it is important to re-test patients who have a palpable abnormality and an initially benign biopsy, and aspiration biopsy simplicity allows for a low threshold of suspicion of subtle abnormalities and for repeating biopsies after negative findings.

Accidental and homicidal death in a psychiatric emergency room population

To identify potentially preventable mortality other than suicide among psychiatric emergency room patients, the authors compared the rates of accidental and homicidal death among 5,284 consecutive psychiatric emergency room patients with those expected for an age-, sex-, and race-matched sample of the general population. The rate of accidental death was two and one-half times and the rate of homicidal death nearly twice the expected rate for the matched general population. Diagnostic and demographic analyses indicated that increased risk of death from either cause was highest among alcoholics, schizophrenic patients, and males. The implications of the findings for clinical care are discussed.

Epidural hematoma as a cause of postpneumonectomy paraplegia

Postpneumonectomy paraplegia developed in a woman admitted for resection of bronchogenic carcinoma. Postpneumonectomy paraplegia is an uncommon, but catastrophic, event that is thought to be caused primarily by ischemia to the spinal cord; in this instance an epidural hematoma was the cause. Recommendations for prevention are presented.

Prescribing practices among nurse practitioners in adult and family health

Data derived through log recordings of 89 nurse practitioners (NPs) in adult/family practice on 7,086 prescriptions issued during 890 clinical days were analyzed to describe prescribing practices of NPs who held prescriptive authority from the licensing regulatory boards of five western states. Results showed drug utilization to be similar to physician prescribing data, and intensity of prescribing to be less than that of physicians. The distributions of prescriptions by drug category and in relation to health problems underlying prescriptions are reported. Confidence with prescribing by type of drugs was parallel to incidence of prescriptions within drug category. Physician consultation prior to prescribing occurred with highest incidence for health problems treated with least frequently prescribed drugs. Physician consultation or referral was reported for 14.3 per cent of prescriptions.

Reduction in prostatic concentration of endogenous dihydrotestosterone in rats by hyperprolactinemia

Persistently high levels of circulating prolactin can be achieved in male rats when pituitaries from female donors are grafted under the renal capsule. Enhanced growth of the lateral prostate can be accomplished by an apparent synergistic effect of excess prolactin with subphysiologic doses of testosterone. To define this effect we measured the endogenous dihydrotestosterone (DHT) concentrations in rat prostate lobes. Twenty Sprague-Dawley male rats (250 g) were castrated and given subcutaneous implants of silastic tubing filled with 1 cm of crystalline testosterone. Ten of these rats simultaneously received two pituitary grafts under the renal capsule. The remaining ten rats received intrarenal skeletal muscle grafts as controls. Four weeks later, the weight (mg +/- SE) of the ventral and dorsal lobes were not significantly different between the two groups, while the lateral lobe was significantly (P less than 0.01) heavier in rats with pituitary grafts (121.4 +/- 7.5) than in controls (81.7 +/- 10.4). Endogenous DHT in the tissue extracts was determined by radioimmunoassay following KMnO4 treatment to eliminate testosterone. The concentration of DHT (ng/g tissue +/- SE) was significantly (P less than 0.01) lower in the lateral prostate of graft-bearing animals (4.40 +/- 0.29) than in the controls (5.98 +/- 0.34). These results indicate that, in the rat, hyperprolactinemia induced by pituitary grafts is associated with a heavier lateral prostate and a lower concentration of endogenous DHT in that tissue. These results also suggest that the action of prolactin in the rat prostate is not mediated through the action of androgen.

An in vitro approach to studying cutaneous metabolism and disposition of topically applied xenobiotics

The extent to which cutaneous metabolism may be involved in the penetration and fate of topically applied xenobiotics was examined by metabolically viable and structurally intact mouse skin in organ culture. Evidence that skin penetration of certain chemicals is coupled to cutaneous metabolism was based upon observations utilizing [14C]benzo[a]pyrene (BP). As judged by the recovery of radioactivity in the culture medium 24 hr after in vitro topical application of [14C]BP to the skin from both control and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced C3H mice, skin penetration of BP was higher in the induced tissue. All classes of metabolites of BP were found in the culture medium; water-soluble metabolites predominated and negligible amounts of unmetabolized BP were found. As shown by enzymatic hydrolysis of the medium, TCDD induction resulted in shifting the cutaneous metabolism of BP toward the synthesis of more water-soluble conjugates. Differences in the degree of covalent binding of BP, via diol epoxide intermediates to epidermal DNA, from control and induced tissues were observed. These differences may reflect a change in the pathways of metabolism as a consequence of TCDD induction. These results indicated that topically applied BP is metabolized by the skin during its passage through the skin; and the degree of percutaneous penetration and disposition of BP was dependent upon the metabolic status of the tissue. This suggests that cutaneous metabolism may play an important role in the translocation and subsequent physiological disposition of topically applied BP.

The distribution of dermal tumorigens in coal liquids: relationship of tumorigenicity and microbial mutagenicity

Polycyclic aromatic hydrocarbons and/or their pyrolle derivatives were found to be the primary contributors to the skin tumorigenicity of the neutral fractions of two coal oils. Mutagenicity of the neutral fraction in Salmonella test strains was found to be due primarily to polycyclic aromatics containing polar substituents. Thus, the chemical classes responsible for skin tumorigenicity differ from those responsible for mutagenicity.

A multisample apparatus for kinetic evaluation of skin penetration in vitro: the influence of viability and metabolic status of the skin

An apparatus is described for convenient in vitro quantitation of the rate, extent, and character of living skin penetration by chemicals. Evidence that viability markedly affects epidermal penetration was based upon observations utilizing benzo(a)pyrene. This compound displayed saturation kinetics in the extent of penetration, marked elevation in the rate, and extent of penetration following induction of epidermal mixed function oxidase and negligible penetration of skin previously frozen. These data are interpreted to indicate that for certain compounds, such as benzo(a)pyrene where cutaneous metabolism is expected, meaningful in vitro measures of skin penetration should take into consideration the biochemical viability and metabolic status of the tissue.

Use of laser-excited fluorescence to measure mixed-function oxidase activity

The microsomal mixed-function oxidase (MFO) system is involved in the metabolism of various chemical compounds. Polycyclic aromatic hydrocarbons are metabolized by the cytochrome P-448 enzyme system, which contains MFOs. Induction of this MFO activity may be useful as an indicator of the toxicity of the inducer material. We have successfully used a portable centrifugal analyzer equipped with an argonion laser light source to quantify cytochrome P-448 activity induced in mouse-liver microsomes by exposing the animal's skin to different doses of liquids derived from a coal-liquefaction process. The MFO activity was determined kinetically by measuring the rate at which the highly fluorescent compound, resorufin, produced by the oxidation of 7-ethoxyresorufin substrate, was formed. The 514.5-nm laser excitation beam was directed with a fiber-optic bundle from the laser to the cuvets of a specially designed rotor; emitted fluorescence was monitored at 90 degrees to the incident beam through a 560-nm cut-on secondary filter. Use of the laser excitation source allowed very low MFO activities to be measured: picomole quantities of resorufin could be determined. We anticipate that the increased sensitivity of the method described here will allow MFO activities to be determined in body fluids and skin.

Use of laser-excited fluorescence to measure mixed-function oxidase activity

The microsomal mixed-function oxidase (MFO) system is involved in the metabolism of various chemical compounds. Polycyclic aromatic hydrocarbons are metabolized by the cytochrome P-448 enzyme system, which contains MFOs. Induction of this MFO activity may be useful as an indicator of the toxicity of the inducer material. We have successfully used a portable centrifugal analyzer equipped with an argonion laser light source to quantify cytochrome P-448 activity induced in mouse-liver microsomes by exposing the animal's skin to different doses of liquids derived from a coal-liquefaction process. The MFO activity was determined kinetically by measuring the rate at which the highly fluorescent compound, resorufin, produced by the oxidation of 7-ethoxyresorufin substrate, was formed. The 514.5-nm laser excitation beam was directed with a fiber-optic bundle from the laser to the cuvets of a specially designed rotor; emitted fluorescence was monitored at 90 degrees to the incident beam through a 560-nm cut-on secondary filter. Use of the laser excitation source allowed very low MFO activities to be measured: picomole quantities of resorufin could be determined. We anticipate that the increased sensitivity of the method described here will allow MFO activities to be determined in body fluids and skin.

Suicide in a psychiatric emergency room population

Twenty-two suicides were identified in a series of 5,284 psychiatric emergency room patients, yielding a suicide rate of 111.1 per 100,000 "patient-years at risk"--more than seven times the age- and sex-adjusted rate for the general population. Subpopulations at high risk were white people, men, depressed and schizophrenic patients, substance abusers, and patients with multiple emergency room visits. No patients had killed themselves immediately after an emergency room visit, but several had killed themselves without following through on a referral from the emergency room to another facility for treatment. The authors discuss the implications of these findings for emergency room practice and for further research.

Quantitation of cutaneous toxicity: an in vitro approach using skin organ culture

A short-term (48 hr) organ culture system for maintaining metabolically viable and structurally intact mouse skin has been developed. With the culture system, the responses of skin to in vitro physical and chemical insults were assessed by histologic examination and selected biochemical measurements in an attempt to establish a quantitative basis for the evaluation of cutaneous toxicity in vitro. In studies with mouse skin in organ culture following either freeze-thaw treatment (physical insult) or a single in vitro topical application of tributyltin chloride (10 to 1000 nmole/cm2), deleterious morphologic changes were observed. The degree of cellular injury was reflected by inhibition of in vitro incorporation of [3H]thymidine and [14C]leucine into epidermal DNA and protein, respectively; there also was leakage of intracellular enzymes into the culture medium in a dose and time related manner. These biochemical parameters are sensitive indicators of cellular injury; as such they may offer a simple, sensitive, and quantitative measure for assessing cutaneous toxicity of chemicals in vitro.

Dosimetry of PAH skin carcinogenesis: covalent binding of benzo[a]pyrene to mouse epidermal DNA

Benzo[a]pyrene (BaP) is metabolized to the chemically reactive anti and syn isomers of the 7,8-diol-9,10-epoxides of BaP (BPDE) which bind covalently to DNA to form DNA/BPDE complexes. Tetrols liberated from the DNA/BPDE complex by acid hydrolysis are easily quantified by h.p.l.c. using fluorescence detection. This approach allows femtomole amounts of BPDE associated with the DNA isolated from a single mouse to be detected using conventional instrumentation. The usefulness of this technique to estimate the interaction of BaP with DNA of mouse skin, both in the intact animal and in organ culture, was investigated. With mouse skin in organ culture it could be demonstrated that: (i) upon a single topical application of 5 micrograms of BaP, binding to DNA occurred via BPDE at a linear rate for up to 65 h, (ii) the amount of binding was dose dependent at concentrations of BaP less than 10 micrograms.

Immunoselection of tumor cell variants by mice suppressed with ultraviolet radiation

It has previously been shown that mice exposed to ultraviolet radiation (UV) fail to reject highly immunogenic UV-induced tumors, which are regularly rejected by normal mice. The present study shows, however, that this immunosuppresion is incomplete, as UV-treated mice can still mount certain tumor-specific immune responses and reject smaller inocula of tumor cells that regularly grow progressively in athymic nude mice. Furthermore, all tumor cell lines that were reisolated from the tumor mass resulting from one tumor passage through UV-treated recipients heritably lost a tumor-specific determinant present on the parental tumor cells used for transplantation, and a large percentage of these reisolated variant tumors had changed to progressively growing tumors, in that they were no longer rejected by normal mice. In contrast, none of the tumors reisolated from passage through athymic nude mice or anti-idiotypically suppressed mice showed this change in antigenicity and progressive growth behavior. Thus, it appears that the phenotypic change in tumors reisolated from UV-treated mice was caused by immunoselection, and that the tumor-specific immunity in these mice apparently restrained the outgrowth of the parental tumor cells despite the partial immunosuppression. Because of the regularity at which tumor variants arose in the UV-treated mice after tumor transplantation, it appears that the partial immunosuppression caused by UV-treatment may have favored the outgrowth of antigenic variants from the parental tumor cell population, possibly by allowing more time for the generation of tumor variants. A similar immunoselection process might be part of tumor progression during tumor development and preferentially occur in cancer-bearing individuals showing concomitant tumor immunity.

Mechanisms of syngeneic tumor rejection. Susceptibility of host-selected progressor variants to various immunological effector cells

The ultraviolet radiation-induced fibrosarcoma 1591 generally is rejected by normal syngeneic mice and only rarely exhibits progressive growth. We isolated five of these rare progressor tumors from normal animals to determine the selective pressures that had been exerted upon the parental tumor by normal immunocompetent hosts. We found that the variant tumor cell lines could neither induce nor be killed by tumor-specific lymphocytes, suggesting that selection had been exerted against tumor cells expressing the tumor-specific antigen. In contrast, no selection against natural killer cell activity or against nonspecific T cell-mediated immunity seems to have occurred because progressor tumor cells were highly sensitive to these types of effector cells and in fact induced these effector cells more effectively than did the parental tumor. Nude mice were found to be as capable as normal mice in generating natural killer activity in response to a challenge with progressor tumor cells, but they were unable to mount a nonspecific T lymphocyte response. This may account for the fact that the progressor tumors grew at a significantly faster rate in nude animals than in normal mice. Thus, our study shows that in this tumor system nonspecific T cell-mediated immunity may play a role in retarding tumor growth, but the absolute resistance of normal animals to progressive tumor growth critically depends upon the presence of T cell-mediated tumor-specific immunity. Furthermore, neither NK cells nor nonspecific cytotoxic T lymphocytes appear to play a role in immunoselection against this tumor in normal immunocompetent hosts.

An anatomic and histologic study of the rat prostate

Various morphologic features of the rat prostate complex were characterized by anatomic dissection and by light microscope histology. The prostate complex is viewed as a whole and it is related to the individual portions of the male reproductive system. The three lobes of the prostate are designated as ventral, lateral, and dorsal according to their relation to the urethra. These lobes are connected to the urethra by fascia and a series of ducts. Relations of the prostate to the seminal vesicles, coagulating glands, vas deferens and ampullary glands, urinary bladder, and ureters are described. Vascular supply is also reviewed. While the acinar pattern of each prostatic lobe is unique, the dorsal and lateral lobes more closely resemble each other than the ventral lobes.

Poly (ADP-ribosylation) in N, N-diethylnitrosamine-treated mice

1. Liver nuclei isolated from male mice treated with the carcinogen N, N-diethylnitrosamine were examined for the homopolymer poly(adenosine diphosphate ribose) and for the activity of the conjugate polymerase. 2. At all levels of the carcinogen tested, a concomitant increase in both poly(adenosine diphosphate ribose) content and activity of the enzyme were found. 3. Both responses were transitory and dose dependent.

Performance of brain-damaged and non-brain-damaged institutionalized children on the Minnesota Percepto-Diagnostic Test

Examined the performance of 64 children on the Minnesota Percepto-Diagnostic test (MPD) who were diagnosed as either Brain-Damaged (BD) or emotionally impaired Non-Brain-Damaged (NBD). There were 31 children in the NBD group and 33 in the BD group. The MPD T-score and Actuarial Table significantly differentiated between the two groups. Seventy-four percent of the combined BD-NBD groups were identified correctly. Additional discriminant analysis on this sample yielded combined BD-NBD groups classification rates that ranged from 77% with the MPD variables Separation of Circle-Diamond (SPCD), Distortion of Circle-Diamond (DCD) and Distortion of Dots (DD) to 83% with the WISC-R three IQ scores plus the MPD T-score, SPCD and DD. The MPD T-score and Actuarial Table (MPD Two-Step Diagnosis) appeared to generalize to other populations more readily than discriminant analysis formulae, which tend to be sensitive to the samples from which they are derived.

Christmas and psychopathology. Data from a psychiatric emergency room population

It is widely believed among psychiatrists and laymen alike that Christmas and other holidays are associated with an increased incidence of psychopathology. Statistical studies, however, consistently have been shown the Christmas season to be associated with a low incidence of suicide and psychiatric hospitalization. The present study examines the number and type of visits to a 24-hour psychiatric emergency service over a seven-year period. There is a decrease in the number of visits during the days and weeks before Christmas and an increase of roughly the same magnitude afterward. The effect is more prominent for women and older persons but does not seem to differentially affect persons of different racial, marital, or diagnostic status.

Induction of O-deethylase activity as an index to exposure to coal-derived products and trace environmental pollutants

The metabolism of the synthetic substrate 7-ethoxyresorufin is a selective measure of the activity of cytochrome P-448 monooxygenase, the subset of cytochrome P-450-mediated enzymes preferentially induced by polycyclic aromatic hydrocarbons and related compounds. 7-Ethoxycoumarin metabolism, on the other hand, reflects total (nonselective) cytochrome P-450 monooxygenase activity. Either substrate yields a single, highly fluorescent product, amenable to direct, sensitive assay with the portable centrifugal analyzer. We used three assays with liver microsomes from C57/BL6 mice for the short-term bioassay of the dose-dependent effects of exposure to selected environmental toxins, including petroleums, polychlorinated biphenyls, and their oxidative degradation products.